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WO2025212628A1 - Method and device for cardiac pressure sensing using an active implantable device and near field communication - Google Patents

Method and device for cardiac pressure sensing using an active implantable device and near field communication

Info

Publication number
WO2025212628A1
WO2025212628A1 PCT/US2025/022515 US2025022515W WO2025212628A1 WO 2025212628 A1 WO2025212628 A1 WO 2025212628A1 US 2025022515 W US2025022515 W US 2025022515W WO 2025212628 A1 WO2025212628 A1 WO 2025212628A1
Authority
WO
WIPO (PCT)
Prior art keywords
imd
pressure data
external
coil
nfc
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/US2025/022515
Other languages
French (fr)
Inventor
Eric Chow
Daniel I. Harjes
Sona Moradi
Eric Lee
Jenna SETTLE
Dan KOVARI
Sam MACNAUGHTON
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TC1 LLC
Original Assignee
TC1 LLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by TC1 LLC filed Critical TC1 LLC
Publication of WO2025212628A1 publication Critical patent/WO2025212628A1/en
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B5/00—Near-field transmission systems, e.g. inductive or capacitive transmission systems
    • H04B5/70—Near-field transmission systems, e.g. inductive or capacitive transmission systems specially adapted for specific purposes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B5/00—Near-field transmission systems, e.g. inductive or capacitive transmission systems
    • H04B5/20—Near-field transmission systems, e.g. inductive or capacitive transmission systems characterised by the transmission technique; characterised by the transmission medium
    • H04B5/24—Inductive coupling
    • H04B5/26—Inductive coupling using coils

Definitions

  • Embodiments of the present disclosure generally relate to methods and devices for acquiring cardiac pressure data and transmitting the data to an external device.
  • BACKGROUND [0003] State of the art commercial implantable heart failure pressure sensors currently rely on complex analog radio frequency (RF) acquisition and tracking to interrogate passive sensors implanted deep (e.g., up to six inches) within the body. This method is prone to signal acquisition issues and sensitivity to noise, movement, and the environment in general.
  • RF radio frequency
  • the current systems can be difficult to use and difficult to obtain a measurement that is consistent, reliable, and accurate.
  • current passive sensors do not have unique serial numbers, patient information or calibration information stored on the device itself, which requires the management of an external device that has to be 15694WOO1 (013-0615PCT1) 1 PATENT manually kept or paired with the patient. Further, since all the data is analog, none of the data is encrypted or protected.
  • the current systems may be difficult for a patient to use at home to obtain measurements that are consistent, reliable, and accurate.
  • the patient places the coil or antenna of the external device on or proximate to their body. The implant is powered via an RF signal transmitted by the external device.
  • Bidirectional communication is based on modulating RF signals between the external system and implant. Due to this wireless functionality of communication and powering, antennas are utilized both on the implant and the external system. The antennas inherently face sensitivity due to variability of the human body composition, location, and distance between the interfacing antennas. For example, the human body has dielectric properties that are different than air, and also vary from person to person as well as from day to day within the same person, which ultimately affects antenna/wireless performance. Also, the coil/antenna of the external system is sensitive to antenna form factor (e.g., belt, sash, pillow, blanket) as well as the positioning of the antenna relative to the body. Other environmental factors such as nearby metal can also impact communication quality.
  • antenna form factor e.g., belt, sash, pillow, blanket
  • an implantable medical device comprises a coil configured to receive near field communication (NFC) signals from an external device and to transmit return NFC signals to the external device.
  • the IMD includes a capacitive element that has a capacitance configured to vary in response to changes in pressure.
  • the IMD also includes an integrated circuit coupled to the capacitive element.
  • the integrated circuit includes at least one of a processor or circuit configured to generate pressure data based on the capacitance of the capacitive element, encode the pressure data to form encoded pressure data, and modulate the return NFC signal, to be transmitted by the coil, based on the encoded pressure data.
  • the at least one of a processor or circuit includes a capacitance to digital (C/D) converter configured to measure the capacitance of the capacitive element and digitally generate the pressure data based on the capacitance of the capacitive element.
  • C/D capacitance to digital
  • the at least one of a processor or circuit is further configured to apply serial encoding to the digital pressure data.
  • the at least one of a processor or circuit is further configured to serial encode the digital pressure data by applying serial encoding.
  • the C/D converter comprises a relaxation oscillator that includes a current source configured to charge and discharge the capacitive element, a first oscillator formed by a feedback loop, and a second 15694WOO1 (013-0615PCT1) 3 PATENT oscillator configured to measure a duration of charge and discharge cycles of the capacitive element, the duration indicative of the capacitance of the capacitive element.
  • the at least one of a processor or circuit is further configured to modulate the return NFC signal utilizing load modulation to transition an impedance of the coil between first and second states corresponding to data values in the encoded pressure data.
  • the transition of the impedance from the first state to the second state corresponds to a logical one in the encoded pressure data and the transition of the impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data.
  • the at least one of a processor or circuit is further configured to apply encryption to the encoded pressure data to form encrypted pressure data, the return NFC signal modulated based on the encrypted pressure data.
  • the at least one of a processor or circuit is further configured to encrypt the encoded pressure data to form encrypted pressure data, the return NFC signal modulated based on the encrypted pressure data.
  • the coil has a length selected within an interval of from 2mm to 20mm, a width selected within an interval of from 1mm to 4mm, and a height selected within an interval of from 0.5mm to 2mm.
  • the coil has a maximum length of 10 mm, a maximum width of 2 mm, and a maximum height of 1 mm.
  • the integrated circuit includes memory configured to store a unique identifier (UID) for the IMD, the integrated circuit configured to combine the UID with the encoded pressure data to modulate the return NFC signal.
  • UID unique identifier
  • the integrated circuit includes a temperature sensor configured to generate temperature data and memory configured to 15694WOO1 (013-0615PCT1) 4 PATENT store the temperature data, the integrated circuit configured to combine the temperature data with the encoded pressure data to modulate the return NFC signal.
  • the IMD is an implantable sensor.
  • the pressure data is indicative of the pressure in a lumen of a body.
  • the integrated circuit includes a capacitance to digital (C/D) converter
  • the method further includes measuring, using the C/D converter, the capacitance of the capacitive element, and digitally generating the pressure data based on the capacitance of the capacitive element.
  • the method further comprises applying serial encoding to the digital pressure data.
  • the method further comprises serially encoding the digital pressure data by applying serial encoding.
  • the C/D converter comprises a relaxation oscillator that includes a current source, a first oscillator, and a second oscillator
  • the method further includes charging and discharging the capacitive element using the current source, forming the first oscillator with a feedback loop, and measuring, using the second oscillator, a duration of charge and discharge cycles of the capacitive element, the duration indicative of the capacitance of the capacitive element.
  • the modulating the return signal further includes modulating the return signal utilizing load impedance modulation and transitioning the load impedance between first and second states corresponding to data values in the encoded pressure data.
  • the transition of the load impedance from the first state to the second state corresponds to a logical one in the encoded pressure data and the transition of the load impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data.
  • the modulating the return signal further includes modulating the return signal utilizing load modulation to transition an impedance of the coil between first and second states corresponding to data values in the encoded pressure data.
  • the transition of the impedance from the first state to the second state corresponds to a logical one in the encoded pressure data and the transition of the impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data 15694WOO1 (013-0615PCT1) 6 PATENT
  • the method further includes encrypting the encoded pressure data to form encrypted pressure data and modulating the return signal based on the encrypted pressure data.
  • the coil has a length selected within an interval of from 2mm to 20mm, a width selected within an interval of from 1mm to 4mm, and a height selected within an interval of from 0.5mm to 2mm.
  • an IMD comprises a coil configured to receive near field communication (NFC) signals from an external device and to transmit return NFC signals to the external device.
  • the IMD further comprises a capacitive element having a capacitance configured to vary in response to changes in pressure, and an integrated circuit coupled to the capacitive element.
  • the integrated circuit includes a capacitance to digital (C/D) converter configured to measure the capacitance of the capacitive element and generate digital pressure data based on the capacitance of the capacitive element.
  • C/D capacitance to digital
  • the IMD further comprises at least one of a processor or 15694WOO1 (013-0615PCT1) 7 PATENT circuit configured to modulate the return NFC signal, to be transmitted by the coil, based on the digital pressure data.
  • the at least one of a processor or circuit is further configured to encode the digital pressure data to form encoded pressure data, and modulate the return NFC signal, to be transmitted by the coil, based on the encoded pressure data.
  • the at least one of a processor or circuit is further configured to serially encode the digital pressure data by applying serial encoding.
  • transition of the impedance from the first state to the second state corresponds to a logical one in the encoded pressure data and the transition of the impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data.
  • the at least one of a processor or circuit is further configured to encode the digital pressure data to form encoded pressure data, and encrypt the encoded pressure data to form encrypted pressure data, the return NFC signal modulated based on the encrypted pressure data.
  • the C/D converter comprises a relaxation oscillator that includes a current source configured to charge and discharge the capacitive element, a first oscillator formed by a feedback loop, and a second 15694WOO1 (013-0615PCT1) 8 PATENT oscillator configured to measure a duration of charge and discharge cycles of the capacitive element, the duration indicative of the capacitance of the capacitive element.
  • the integrated circuit further includes memory configured to store a unique identifier (UID) for the IMD, wherein the at least one of a processor or circuit is further configured to encode the digital pressure data to form encoded pressure data, and combine the sensor UID with the encoded pressure data to modulate the return NFC signal.
  • UID unique identifier
  • the integrated circuit includes a temperature sensor configured to generate temperature data and memory configured to store the temperature data, wherein the at least one of a processor or circuit is further configured to encode the digital pressure data to form encoded pressure data, and combine the temperature data with the encoded pressure data to modulate the return NFC signal.
  • the IMD is an implantable sensor.
  • the digital pressure data is indicative of a pressure in a lumen of a body.
  • a method for generating signals to transmit from an IMD to an external device includes receiving, via a coil communicatively connected to the IMD, near field communication (NFC) signals from the external device and measuring, via a capacitance to digital (C/D) converter, capacitance of a capacitance element.
  • the C/D converter is included within an integrated circuit coupled to the capacitive element.
  • the capacitive element has the capacitance configured to vary in response to changes in pressure.
  • the method further includes generating digital pressure data, via the C/D converter, based on the capacitance of the capacitive element.
  • the method further includes modulating a return signal, using at least one of a processor or circuit included within the integrated circuit, based on the digital pressure data. 15694WOO1 (013-0615PCT1) 9 PATENT [0054] Optionally, the method further includes transmitting the return signal utilizing the coil. [0055] Optionally, the method further includes encoding the digital pressure data to form encoded pressure data, and modulating the return signal, to be transmitted by the coil, based on the encoded pressure data. [0056] Optionally, the method further includes serially encoding the digital pressure data by applying serial encoding.
  • the serial encoding is one of: Non-Return-to-Zero (NRZ) encoding, Non-Return-to-Zero-Inverted (NRZI) encoding, Return-to-Zero (RZ) encoding, or Manchester encoding.
  • the method further includes encoding the digital pressure data to form encoded pressure data, and modulating the return signal utilizing load modulation to transition an impedance of the coil between first and second states corresponding to data values in the encoded pressure data.
  • the transition of the impedance from the first state to the second state corresponds to a logical one in the encoded pressure data and the transition of the impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data.
  • the method further includes encoding the digital pressure data to form encoded pressure data, encrypting the encoded pressure data to form encrypted pressure data and modulating the return signal based on the encrypted pressure data.
  • the C/D converter comprises a relaxation oscillator including a current source, a first oscillator, and a second oscillator
  • the method further includes charging and discharging the capacitive element using the current source, forming the first oscillator with a feedback loop, and measuring, using the second oscillator, a duration of charge and discharge cycles of the capacitive element, the duration indicative of the capacitance of the capacitive element.
  • an implantable medical device comprises a coil configured to receive near field communication (NFC) signals from an external device and to transmit return NFC signals to the external device, a capacitive element having a capacitance configured to vary in response to changes in pressure, and an integrated circuit coupled to the capacitive element.
  • the integrated circuit includes at least one of a processor or circuit configured to generate pressure data based on the capacitance of the capacitive element, and modulate the return NFC signal, to be transmitted by the coil, based on the pressure data.
  • a method for managing inductive communication between an implantable medical device (IMD) and an external device, the external device having an inductive external coil configured to be located proximate to a body, the IMD configured to be located within the body.
  • the method includes transmitting, by the inductive external coil, inductive external near field communication (NFC) signals to an inductive IMD coil, and receiving, via the inductive external coil, inductive IMD NFC signals from the inductive IMD coil.
  • NFC near field communication
  • the method further includes determining a characteristic of interest (COI) based on the inductive IMD NFC signals, and dynamically tuning at least one of the inductive external coil or the inductive IMD coil based on the COI.
  • COI characteristic of interest
  • the COI is a voltage level associated with the inductive IMD NFC signals
  • the dynamically tuning further includes dynamically tuning at least one of the inductive external coil or the inductive IMD coil based on a reflection coefficient associated with the COI.
  • the COI is a voltage level of the inductive IMD NFC signals
  • the dynamically tuning further includes dynamically tuning at least one of the inductive external coil or the inductive IMD coil based on a reflection coefficient of the COI.
  • the dynamically tuning further includes changing at least one parameter of an external tunable matching network associated with the inductive external coil to minimize a reflection coefficient associated with the COI.
  • the COI is a voltage level of the inductive IMD NFC signals
  • the dynamically tuning further includes changing at least one parameter of an external tunable matching network communicatively connected to the inductive external coil to minimize a reflection coefficient of the COI.
  • the dynamically tuning further includes dynamically changing at least one parameter of an external tunable matching network communicatively connected to the inductive external coil to minimize a reflection coefficient of the COI.
  • the changing at least one parameter of the external tunable matching network includes i) opening or closing a switch in the external tunable matching network, ii) adjusting an adjustable component in the external tunable matching network, or iii) increasing or decreasing an input voltage to the external tunable matching network to adjust an impedance of the inductive external coil.
  • the COI is an IMD received signal strength indicator (RSSI), and the COI is included in a data packet transmitted by the inductive IMD coil.
  • the COI is an IMD RSSI
  • the method further includes determining an external RSSI associated with the inductive IMD NFC signals, and wherein the dynamically tuning further includes configuring a network configuration of an external tunable matching network associated with the inductive external coil or an IMD tunable matching network associated with the inductive IMD coil to maximize one of the IMD RSSI or external RSSI.
  • the COI is an IMD RSSI
  • the method further includes determining an external RSSI associated with the inductive IMD NFC signals
  • the dynamically tuning further includes dynamically configuring a network configuration of an external tunable matching network communicatively connected to the inductive external coil or an IMD tunable matching network communicatively connected to the inductive IMD coil to maximize one of the IMD RSSI or external RSSI.
  • the dynamically tuning further includes changing i) at least one parameter of an external tunable matching network associated with the inductive external coil or ii) at least one parameter of an IMD tunable matching network associated with the inductive IMD coil.
  • the dynamically tuning further includes changing i) at least one parameter of an external tunable matching network communicatively connected to the inductive external coil or ii) at least one parameter of an IMD tunable matching network communicatively connected to the inductive IMD coil.
  • the dynamically tuning further includes dynamically changing i) at least one parameter of an external tunable matching network communicatively connected to the inductive external coil or ii) at least one parameter of an IMD tunable matching network communicatively connected to the inductive IMD coil
  • the method further includes transmitting, by the inductive external coil, successive inductive external NFC signals to the inductive IMD coil, receiving, via the inductive external coil, successive inductive IMD NFC signals from the inductive IMD coil, the successive inductive IMD NFC signals including IMD data measurements, determining a successive COI based on the successive inductive 15694WOO1 (013-0615PCT1) 14 PATENT IMD NFC signals, and wherein the dynamically tuning further comprising dynamically tuning at least one of the inductive external coil or the inductive IMD coil based on the successive COI.
  • the method further includes setting an output power of the inductive external coil at an initial level, and in response to not receiving, via the inductive external coil, the inductive IMD NFC signals from the inductive IMD coil, increasing the output power of the inductive external coil.
  • the COI is a phase difference between the inductive external NFC signals and the inductive IMD NFC signals
  • the method further includes determining if the COI satisfies a phase difference threshold, and in response to satisfying the phase difference threshold, changing i) at least one parameter of an external tunable matching network associated with the inductive external coil or ii) at least one parameter of an IMD tunable matching network associated with the inductive IMD coil.
  • the method further includes, in response to a decrease in the output power of the external device, changing at least one parameter of an external tunable matching network communicatively connected to the inductive external coil, and transmitting, by the inductive external coil, successive 15694WOO1 (013-0615PCT1) 15 PATENT inductive external NFC signals to the inductive IMD coil.
  • the method further includes receiving, via the inductive external coil, successive inductive IMD NFC signals from the inductive IMD coil, the successive inductive IMD NFC signals including IMD data measurements, determining a successive COI based on the successive inductive IMD NFC signals, and wherein the dynamically tuning further comprising dynamically tuning the inductive external coil based on the successive COI.
  • the method further includes evaluating i) an IMD RSSI, ii) an external RSSI, iii) a reflection coefficient of or associated with the COI, iv) a phase difference between the inductive external NFC signals and the inductive IMD NFC signals, or v) an output power of the external device.
  • the inductive IMD NFC signals include IMD data measurements.
  • an external device for managing inductive communication between an implantable medical device (IMD) and the external device is provided.
  • the external device includes an inductive external coil configured to transmit inductive external near field communication (NFC) signals to the IMD and receive inductive IMD NFC signals from an inductive IMD coil communicatively connected to the IMD.
  • the external device further includes at least one of a processor or circuit configured to utilize the inductive external coil to transmit the inductive external NFC signals to the inductive IMD coil, receive, via the inductive external coil, inductive IMD NFC signals from the inductive IMD coil, determine a characteristic of interest (COI) based on the inductive IMD NFC signals, and dynamically tune at least one of the inductive external coil or the inductive IMD coil based on the COI.
  • COI characteristic of interest
  • the inductive external coil includes an external tunable matching network including one or more of i) a pi-match network, ii) an L-match network, iii) a T-match network, iv) a combination of two of more of pi- match, L-match, or T-match networks, v) a series of two or more of pi-match, L-match, or T-match network, or vi) an adjustable component.
  • the inductive external coil is conformable.
  • the inductive IMD NFC signals include data measurements.
  • the IMD is a pressure sensor and the inductive IMD NFC signals include pressure measurements.
  • the inductive external coil is configured to be located proximate to a body, the IMD configured to be located within the body.
  • the IMD is an implantable sensor.
  • the IMD is an implantable sensor configured to generate pressure data indicative of pulmonary arterial pressure.
  • the IMD is an active device configured to deliver therapy to a patient.
  • the IMD is a passive device configured to generate data associated with a patient.
  • the COI is a voltage level of the inductive IMD NFC signals
  • the dynamically tune further comprises dynamically tune at least one of the inductive external coil or the inductive IMD coil based on a reflection coefficient of the COI.
  • the inductive external coil further comprises an external tunable matching network
  • the COI is a voltage level of the inductive IMD NFC signals
  • the dynamically tune further comprising changing at least one parameter of the external tunable matching network to minimize a reflection coefficient of the COI.
  • the changing at least one parameter of the external tunable matching network comprises i) opening or closing a switch in the external tunable matching network, ii) adjusting an adjustable component in the external tunable matching network, or iii) increasing or decreasing an input voltage to the external tunable matching network to adjust an impedance of the inductive external coil.
  • the inductive external coil further comprises an external tunable matching network comprising a plurality of switches, wherein each of the plurality of switches is configured to electrically connect and disconnect one or more components, wherein, in response to the COI comprising an IMD RSSI, the at least one of a processor or circuit is further configured to determine an external RSSI; and dynamically tune the inductive external coil by opening or closing at least one of the plurality of switches to maximize one of the IMD RSSI or external RSSI.
  • the COI is a phase difference between the inductive external NFC signals and the inductive IMD NFC signals
  • the at least one of the processor or circuit further configured to determine if the COI satisfies a phase difference threshold; and in response to satisfying the phase difference threshold, change i) at least one parameter of an external tunable matching network communicatively connected to the inductive external coil or ii) at least one parameter of an IMD tunable matching network communicatively connected to the inductive IMD coil.
  • the at least one of the processor or circuit further configured to determine if an output power of the external device satisfies a power threshold; and in response to the output power satisfying the power threshold, decrease the output power.
  • the at least one of the processor or circuit further configured to evaluate i) an IMD RSSI, ii) an external RSSI, iii) a reflection coefficient associated with the COI, iv) 15694WOO1 (013-0615PCT1) 19 PATENT a phase difference between the inductive external NFC signals and the inductive IMD NFC signals, or v) an output power of the external device.
  • IMD implantable medical device
  • FIG. 1A illustrates a system that includes an implantable medical device (IMD), such as an implantable pressure sensor, and an external device implemented in accordance with embodiments herein.
  • Figure 4B shows an exploded view of the IMD (e.g., pressure sensor) in accordance with embodiments herein.
  • Figures 4C and 4D show isometric views of the IMD (e.g., pressure sensor) without and with the top glass included, respectively, in accordance with embodiments herein.
  • Figure 4E shows a portion of the IMD (e.g., pressure sensor) having direct wirebond interconnections to the integrated circuit in accordance with embodiments herein.
  • Figure 4F shows the portion of the IMD (e.g., pressure sensor) as discussed in Figure 4D having a resonant capacitor in accordance with embodiments herein.
  • Figure 4M is a top view of the IMD (e.g., pressure sensor) showing the interconnects directly attaching to the integrated circuit in accordance with embodiments herein.
  • Figure 5 illustrates an example process flow for calibrating the IMD (e.g., pressure sensor) in accordance with embodiments herein.
  • Figure 6 illustrates an example process flow for identifying and baselining the IMD (e.g., pressure sensor) during implantation in accordance with embodiments herein.
  • Figure 7 illustrates an example process flow for acquiring pressure readings sensed by the IMD (e.g., pressure sensor) in accordance with embodiments herein.
  • Figure 8 illustrates a digital healthcare system implemented in accordance with embodiments herein.
  • Figure 9A illustrates a system wherein the external device uses near field communication (NFC) to power and receive data from the IMD in accordance with embodiments herein.
  • Figure 9B illustrates a block diagram of the integrated circuit within the IMD in accordance with embodiments herein.
  • Figure 9C illustrates an exemplary external device for communicating with an IMD implanted within a body in accordance with embodiments herein.
  • NFC near field communication
  • Figure 10A illustrates an example of an IMD matching network communicatively connected to the IMD coil/antenna and an external matching network communicatively connected to the external coil/antenna, the matching networks having a simple pi-match network topology in accordance with embodiments herein.
  • Figure 10B illustrates an example wherein the external matching network of the external device is an L-match topology in accordance with embodiments herein.
  • Figure 10C illustrates an example wherein the external matching network of the external device is a T-match topology in accordance with embodiments herein.
  • Figure 10D illustrates an example of the IMD matching network and the external matching network having a back-to-back L-match network topology in accordance with embodiments herein.
  • Figure 11 illustrates an example process flow for setting an output power of the external device (e.g., reader) for acquiring IMD data measurements, sensed and/or determined by the IMD, in accordance with embodiments herein.
  • Figure 12 illustrates an example process flow for dynamically receiving IMD data measurements and tuning the external coil/antenna to minimize the reflection coefficient in accordance with embodiments herein.
  • Figure 13 illustrates an example process flow for dynamically receiving IMD data measurements and tuning the external coil/antenna based on IMD RSSI and external device RSSI in accordance with embodiments herein.
  • Figure 14 illustrates an example process flow for dynamically receiving IMD data measurements and tuning the external coil/antenna to optimize the phase difference between transmit and receive signals in accordance with embodiments herein.
  • Figure 15 illustrates an example process flow for tuning the external coil/antenna based on a time interval in accordance with embodiments herein.
  • Figure 16 illustrates an example process flow for tuning the external coil/antenna based on the phase difference between the transmit and receive signals in accordance with embodiments herein.
  • Non-limiting examples of IMDs include one or more of neurostimulator devices, implantable leadless monitoring and/or therapy devices, and/or alternative implantable medical devices.
  • the IMD may represent a subcutaneous cardioverter defibrillator, cardiac monitoring device, pacemaker, cardioverter, cardiac rhythm management device, defibrillator, neurostimulator, leadless monitoring device, leadless pacemaker, left atrial or pulmonary artery pressure sensor, blood glucose monitoring device, and the like.
  • the IMD may measure electrical, mechanical, impedance, blood glucose, or pressure information.
  • the IMD may include one or more structural and/or functional aspects of the device(s) described in U.S.
  • Patent Number 9,333,351 entitled “Neurostimulation Method And System To Treat Apnea” issued May 10, 2016 and U.S. Patent Number 9,044,610, entitled “System And Methods For Providing A Distributed Virtual Stimulation Cathode For Use With An Implantable Neurostimulation System” issued June 02, 2015, and U.S. patent application publication no. US 2023/0109023, entitled “System and Method for Intra-Body Communication of Sensed Physiologic Data”, filed August 15694WOO1 (013-0615PCT1) 29 PATENT 18, 2022, which are hereby incorporated by reference.
  • the IMD may monitor transthoracic impedance, such as implemented by the CorVue algorithm offered by St. Jude Medical.
  • the IMD may be a leadless cardiac monitor (ICM) that includes one or more structural and/or functional aspects of the device(s) described in U.S.
  • NFC can be preferably utilized for communication within the complex medical system that includes the pressure sensor implanted within a patient’s body and the external device located outside the patient’s body.
  • the integrated circuit includes memory configured to store various types of information, including calibration information, patient information, and a unique serial number assigned to the implantable sensor.
  • methods and devices are described that automatically and dynamically tune the IMD tunable matching network of an IMD coil communicatively connected to an IMD receiving power from an external device to optimize the NFC link between the IMD and the external device.
  • the matching can become detuned.
  • the tuning can be done continuously, periodically, based on a trigger or measured/detected parameter, on-demand, etc., as the environment and form factor can be dynamic.
  • the components of the matching networks of the external device and/or IMD discussed herein can, preferably, be dynamically and automatically adjusted to configure different matching network configurations.
  • the adjustment can be done by implementing a bank of components and switching them in and out with switches.
  • adjustable components can be used.
  • varactor(s) can be included in a matching network to change the capacitance with voltage (i.e., varying the voltage to vary the capacitance).
  • potentiometer(s) can be 15694WOO1 (013-0615PCT1) 40 PATENT included in a matching network to change the resistance of the matching network.
  • a sub-set of the entire range, a course sweep (larger steps), fine sweep (smaller steps), etc., can be evaluated.
  • power levels are monitored to ensure that the power remains within desired levels to maintain performance (e.g., powering the implanted system and achieving successful communication), to not waste power, and to prevent damage to sensitive components.
  • desired levels e.g., powering the implanted system and achieving successful communication
  • the RSSI values can then be determined continuously, periodically, on-demand, etc., and used to adjust the power if needed.
  • the preferable dynamic tuning of the matching network(s) of the coil(s)/antenna(s) provides improvements to the technical field of communicating bidirectionally and powering implantable medical devices.
  • the embodiments can provide technical improvements to one or both external devices and IMDs that communicate using NFC.
  • the IMD 150 when the IMD 150 is disposed within the PA, the IMD 150 may sense, as the PPOI, blood pressure.
  • the external device 104 is capable of energizing and communicating with multiple IMDs.
  • IMD 152 can also be a pressure sensor, which in this example is located within a chamber of the heart.
  • Other IMDs capable of NFC communication are also contemplated, and can be implanted and/or affixed to a patient’s skin (e.g., partially implanted) in areas of the body other than those discussed and/or shown in Figures 1A-1C.
  • a glucose monitor, neurostimulator, body generated analyte test device, etc. can also communicate with the external device 104.
  • an IMD may have its own power, such as a battery, but communicate via an implantable coil with the external device 104 using NFC. 15694WOO1 (013-0615PCT1) 44 PATENT [00196]
  • Figure 1B illustrates possible locations wherein one or more IMD 150, such as the implantable pressure sensor, may be implanted within the patient in accordance with embodiments herein.
  • the one or more of IMDs 150 can be configured to collect blood pressure data at different locations within the patient. When more than one IMD 150 is implanted, the IMDs 150 may operate independently or in cooperation with one another.
  • the system of the IMD 150 and the external device 104 can include other implantable device(s), semi-implantable device(s) (e.g., devices attached to and extending into the skin of the patient such as a continuous glucose monitor), and external devices (e.g., wearables). These devices can communicate information to the external device 104 that can be correlated in time with the data received by the external device 104 over NFC from the IMD150.
  • Figure 1C illustrates an embodiment, in which an IMD 150, such as the implantable pressure sensor, and a second IMD 100, such as an implantable cardiac monitor, are implanted within a patient in accordance with embodiments herein.
  • the IMD 100 may represent various other types of implantable medical devices, such as a pacemaker, cardioverter- defibrillator, leadless pacemaker, neurostimulator and the like.
  • the IMD 150 may communicate with one or both of the external 15694WOO1 (013-0615PCT1) 45 PATENT device 154 and IMD 100.
  • the IMD 150 may communicate with the IMD 100 using conducted telemetry.
  • the IMD 150 may communicate with an IMD 100 that delivers therapy such as described in US application serial no.63/596,402, filed November 6, 2023, titled “System and Method for Diastolic- Enhanced Systolic Peak Detection” which is hereby incorporated by reference in its entirety.
  • the IMD 100 may communicate directly with the external device 154.
  • the IMD 100 is intended for subcutaneous implantation at a site near the heart.
  • the IMD 100 includes a pair of spaced-apart sense electrodes 114, 126 positioned with respect to a housing 102.
  • the sense electrodes 114, 126 provide for detection of far field electrogram signals. In one example, far field CA signals for a series of beats are obtained. Numerous configurations of electrode arrangements are possible.
  • the electrode 114 may be located on a distal end of the IMD 100, while the electrode 126 is located on a proximal side of the IMD 100. Additionally, or alternatively, electrodes 126 may be located on opposite sides of the IMD 100, opposite ends or elsewhere.
  • the distal electrode 114 may be formed as part of the housing 102, for example, by coating all but a portion of the housing with a nonconductive material such that the uncoated portion forms the electrode 114.
  • the electrode 126 may be electrically isolated from the housing electrode 114 by placing it on a component separate from the housing 102, such as the header 120.
  • the header 120 may be formed as an integral portion of the housing 102.
  • the header 120 includes an antenna 128 and the electrode 126.
  • the antenna 128 is configured to wirelessly communicate with the external device 154 and/or IMD 150 in accordance with one or more predetermined wireless protocols (e.g., Bluetooth, Bluetooth low energy, Wi-Fi, etc.).
  • the IMD 150 includes an inductive IMD coil 202 (e.g., IMD antenna) for communications and power transfer, an integrated circuit 204 (e.g., ASIC), and a Micro-Electromechanical Systems (MEMS) capacitive element 206 for use as a pressure transducer.
  • IMD coil 202 e.g., IMD antenna
  • integrated circuit 204 e.g., ASIC
  • MEMS Micro-Electromechanical Systems
  • the MEMS capacitive element 206 is also referred to herein as a capacitive sensor.
  • the capacitive element is a non-inductive capacitive 15694WOO1 (013-0615PCT1) 47 PATENT element or non-L capacitive element.
  • ASIC and integrated circuit can be used herein interchangeably.
  • the inductive IMD coil 202 is coupled to the integrated circuit 204 and the integrated circuit 204 is coupled to the MEMS capacitive element 206 as discussed further herein.
  • the integrated circuit 204 further includes an IMD NFC transceiver 208 (e.g., capable of receiving and/or transmitting NFC), memory 210, and typically, a capacitance to digital (C/D) converter 212.
  • IMD NFC transceiver 208 e.g., capable of receiving and/or transmitting NFC
  • memory 210 e.g., capable of receiving and/or transmitting NFC
  • C/D capacitance to digital
  • the capacitance of the MEMS capacitive element 206 will vary as a function of the environmental pressure. In other words, the capacitive element 206 has a capacitance configured to vary in response to changes in pressure.
  • the integrated circuit 204 interfaces with the MEMS capacitive element 206, such as via the C/D converter 212, to measure the capacitance values.
  • the memory 210 is a tangible and non-transitory computer-readable storage medium. In some embodiments, logic is hard coded, such as by using digital transistors, on the integrated circuit 204 to perform the operations of the IMD 150. In some embodiments, the memory 210 can be a non-volatile memory (NVM).
  • NVM non-volatile memory
  • the memory 210 stores program instructions (e.g., software) that are executed by one or more processors of the integrated circuit 204 to perform the operations of the IMD 150 described herein. Additionally, or alternatively, the memory 210 stores information, such as physiologic data generated by the MEMS capacitive element 206, information generated by the C/D converter 212, calibration information, serial number, etc. In some embodiments, the memory 210 may store the physiologic data and/or the information of the C/D converter 212 until it is transmitted to the IMD 100 and/or the external device 104.
  • program instructions e.g., software
  • the memory 210 stores information, such as physiologic data generated by the MEMS capacitive element 206, information generated by the C/D converter 212, calibration information, serial number, etc.
  • the memory 210 may store the physiologic data and/or the information of the C/D converter 212 until it is transmitted to the IMD 100 and/or the external device 104.
  • an inductive external coil 231 (e.g., external antenna) communicatively connected to the external device 104 may be designed with a size to generate a larger field, such as to ensure communication of up to six inches deep within the patient’s body. External coil dimensions of at least 4” to 12” (e.g., 10.16 cm to 30.48 cm) in radius may be used.
  • the inductive external coil 231 can either be embedded in a pillow or blanket to be positioned underneath or on top of the patient, or embedded in other concepts like a sash or belt.
  • the IMD 150 includes a housing 214 that holds and encapsulates the inductive IMD coil 202, integrated circuit 204, and MEMS capacitive element 206 to protect these components from the harsh organic environment of the body.
  • the housing 214 may be hermetically sealed.
  • Figure 2B illustrates an example of the MEMS capacitive element 206 formed in accordance with embodiments herein.
  • the element 206 includes at least one lower electrode 207, 209 (e.g., lower electrode) formed on pedestal 416 and an electrode 211 (e.g., upper electrode) formed on an inner surface of glass 412.
  • the pedestal 416 and glass 412 are discussed further below.
  • An air gap 213 separates the electrode 207, 209 and the electrode 211.
  • the electrode 207, 209, 211 are each a metallized layer.
  • the below description of the MEMS capacitive element 206 is an example and represents only one implantable sensor 15694WOO1 (013-0615PCT1) 49 PATENT that may be used together with the new and unique aspects discussed herein. Additionally, or alternatively, other implantable sensors having a pressure- dependent circuit can be used.
  • MEMS capacitive element 206 can be found in at least US published application number 2022/0079456, filed October 21, 2021, titled “System and method for calculating a lumen pressure utilizing sensor calibration parameters”; US patent 9,792,469, filed October 17, 2016, titled “Wireless Physical Property Sensor with Digital Communications”; and US patent 9,653,926, filed May 21, 2015, titled “Physical Property Sensor with Active Electronic Circuit and Wireless Power and Data Transmission”, which are hereby incorporated by reference in their entireties.
  • the capacitor in the MEMS capacitive element 206 consists of at least two conductive elements (e.g., electrodes 207, 209 and electrode 211) separated by the gap 213.
  • the preferred integrated circuit 204 includes two main building blocks, preferably the C/D converter 212 and preferably an NFC block 216.
  • additional blocks include temperature measurement, typically utilizing a temperature sensor 218, preferably the memory 210 (e.g., one-time-programmable (OTP) memory, non-volatile memory (NVM)), 15694WOO1 (013-0615PCT1) 50 PATENT preferably power regulation block 220, and preferably resonant capacitor and tuning trim 222.
  • OTP one-time-programmable
  • NVM non-volatile memory
  • 15694WOO1 e.g., 15694WOO1 (013-0615PCT1
  • the NFC block 216 is interconnected to the inductive coil 202 via connections 228, 230.
  • the NFC block 216 preferably includes power harvesting 248 to collect energy from the transmitted NFC and provide power to the power regulation block 220 via connection 232, which in turn can power the memory 210 via connection 234, the C/D converter 212 via connection 236, and temperature sensor 218 via connection 237.
  • hard coded logic e.g., circuit, circuitry
  • the NFC block 216 includes and/or is in communication with one or more preferred processor 246 incorporated within the integrated circuit 204 that is configured to accomplish requests, receive data, output data via NFC, and the like.
  • the power regulation block 220 takes the power from the NFC power harvesting 248 and generates stable voltages and currents to power the integrated circuit 204.
  • the NFC field will not be a constant value, varying due to a plurality of environmental factors including the distance between the external device 104 and the IMD 150.
  • the power regulation block 220 provides a stable voltage and current to the integrated circuit 204 in order to perform consistently and take accurate measurements.
  • the power regulation block 220 can preferably include OTP/NVM read/write functionality 221. Writing to memory 210 takes a lot of power and needs accurate power regulation. In some cases, the power regulation may need to boost up the voltage in order to write to the memory 210 effectively.
  • the OTP/NVM read/write functionality 221 captures the aspects of power regulation that are needed to write to the memory 210.
  • the power regulation block 220 controls when the applicable blocks are powered. In some embodiments, the C/D converter 212 will always be powered when power is available. In other embodiments, the memory 210 will only be 15694WOO1 (013-0615PCT1) 51 PATENT powered in specific times when a write to memory instruction or read from memory instruction is received.
  • the optional temperature sensor 218 receives a temperature request 224 from the NFC block 216 and sends back temperature data 226. The temperature sensor 218 measures the immediate temperature, such as of the integrated circuit 204. For example, as the integrated circuit 204 is powered by NFC, the temperature can increase.
  • the memory 210 preferably stores a unique identifier (UID) 242 or other identifier(s) (e.g., unique sensor identifier, unique serial number) assigned to the IMD 150.
  • UID unique identifier
  • other identifier(s) e.g., unique sensor identifier, unique serial number
  • the memory 210 preferably also stores calibration information 244 (e.g., coefficients) that can be determined during manufacturing, once the IMD 150 is assembled, upon implant within a patient, and/or updated after being implanted within a patient for a period of time.
  • calibration information 244 is a set of coefficients that represent how the specific MEMS capacitive element 206 performs, and can include, for example, coefficient values and offsets due to temperature and dielectric effect.
  • the memory 210 preferably stores baseline information 258 that is acquired and stored during the implant procedure.
  • the external device 104 can direct the integrated circuit 204 to store the baseline information during the implant procedure.
  • the memory 210 may also store a patient identifier, such as a patient ID within a medical network, a social security number, and the like. [00217]
  • the memory 210 receives an information request 238 from the NFC block 216 and sends back the requested information 240, such as the UID 242, the calibration information 244, and/or baseline information 258.
  • the memory 210 may store the pressure data 256 once digitized by the C/D converter 15694WOO1 (013-0615PCT1) 52 PATENT 212.
  • the pressure data may be stored in a buffer (e.g., a first in first out buffer) or other type of memory before transmission to the external device 104.
  • calibration information 244 is a set of coefficients that represent how the specific MEMS capacitive element 206 performs.
  • the pressure is varied and how the frequency (the frequency corresponds to capacitance) changes is measured.
  • the relationship between the two is modeled with a second order polynomial fit. That second order polynomial has three coefficients that are determined during manufacturing.
  • the coefficients are written into the memory 210 as the calibration information 244 of the integrated circuit 204 during manufacturing. Calibration is discussed further below in Figure 5.
  • Baselining is accomplished during and after implantation of the IMD 150. During the implant procedure, the physician will also feed in a pressure measuring catheter.
  • the pressure that the pressure measuring catheter measures is then compared with the pressure measured by the IMD 150, and any differences are “baselined”. In some embodiments, the value the IMD 150 provides is baselined to the pressure measured by the pressure measuring catheter. Baselining is discussed further below in Figure 6.
  • the one or more processors 246 or other circuitry of the integrated circuit 204 can accomplish fault detection within the integrated circuit 204 and MEMS capacitive element 206. Faults that can be detected include, but are not limited to, capacitance to digital conversion including built in self test (e.g., BIST), within the memory 210, within processing, and shunts and/or opens associated with (e.g., within and/or connected to) the MEMS capacitive element 206.
  • built in self test e.g., BIST
  • the integrated circuit 204 can detect an anomalous reading (e.g., due to EMC, noise). For example, a current reading (or spike) by the MEMS capacitive element 206 that is greater than 10fF (approximately 4 mmHg) from the expected value or reading can be treated as anomalous.
  • the expected reading can be a previous reading or the most recent reading, while in other cases the expected reading can be based on 15694WOO1 (013-0615PCT1) 53 PATENT an average of previous readings, such as the average of a number of the previous readings (e.g., 10, 20, 30 readings).
  • the integrated circuit 204 will send a fault bit along with each measurement.
  • the telemetry controls the trimming (e.g., tells which trim bits to enable/disable) and the NFC powering provides the power needed to write into the memory 210.
  • the one or more processors 246 or other circuitry of the integrated circuit 204 further provide the ability to store implant baseline information in the memory 210, such as during an implant procedure or other procedure.
  • the NFC block 216 Upon receiving power via the NFC coil 202, the NFC block 216 can “wake up” and send a measurement request 254 to the C/D converter 212.
  • the C/D converter 212 powered by the power regulation block 220, converts the 15694WOO1 (013-0615PCT1) 54 PATENT capacitance into a digital word that represents the pressure within the area around the MEMS capacitive element 206 at the particular point in time.
  • capacitance There are numerous methods to measure capacitance including a step response, relaxation oscillator, voltage divider, and bridge configuration.
  • a modified version of the relaxation oscillator consists of current sources to charge and discharge the MEMS capacitive element 206, a feedback loop to form an oscillator (denoted first oscillator herein), and then a second oscillator used to measure the time of the charge and discharge cycles, which corresponds to the MEMS capacitor value.
  • FIG. 3B illustrates an exemplary C/D converter 212 implemented as a modified version of the relaxation oscillator in accordance with embodiments herein.
  • the C/D converter 212 measures capacitance directly.
  • a constant current source is used, the MEMS capacitive element 206 is charged up, and the charging time is measured.
  • current source 260 turns on and digital counter 262 starts to count.
  • FIG. 3C illustrates an implementation of the C/D converter 212 with transistors in accordance with embodiments herein.
  • CMOS complementary metal-oxide semiconductor
  • current source 280 can be implemented with a P-type metal-oxide semiconductor (PMOS) transistor and discharge switch 282 can be implemented with an N-type metal oxide semiconductor (NMOS).
  • PMOS P-type metal-oxide semiconductor
  • NMOS N-type metal oxide semiconductor
  • the C/D converter 212 sends pressure data 256 to the NFC block 216.
  • the one or more processors 246 or other circuitry of the integrated circuit 204 can encrypt the pressure data, serial number, temperature, etc., prior to transmitting the data to the external device 104.
  • the IMD 150 shown in Figure 1A, implanted within the pulmonary artery, and the IMD 152, located within a chamber of the heart, can be interrogated simultaneously, as the external device 104 can distinguish the source of the data based on unique identifier(s).
  • Near Field Communication [00231]
  • the pressure measurement is captured and converted into a digital word (e.g., digitized) by the C/D converter 212, the pressure data is sent to the NFC block 216 for encoding (e.g., adding information such as error bit) to form encoded pressure data.
  • the encoded pressure data may further be encrypted (e.g., encryption 250). The encoded and/or encrypted pressure data is then utilized to modulate the return signal.
  • NFC Type 5 which was released in 2015, is based on Radio Frequency Identification (RFID) technology defined by ISO/IEC 15693, operates at 13.56 MHz, and enables a longer range, up to 1.5 meters, than what was previously achievable (e.g., typically 10 cm or less).
  • RFID Radio Frequency Identification
  • ISO/IEC 15693 operates at 13.56 MHz, and enables a longer range, up to 1.5 meters, than what was previously achievable (e.g., typically 10 cm or less).
  • RFID Radio Frequency Identification
  • ISO/IEC 15693 operates at 13.56 MHz, and enables a longer range, up to 1.5 meters, than what was previously achievable (e.g., typically 10 cm or less).
  • RFID Radio Frequency Identification
  • NFC is a very non-obvious choice for telemetry because NFC is generally targeted for larger coils and very short distances.
  • Some examples of NFC devices operate at 13.56 Megahertz (MHz). The following is a non-exhaustive list of examples of NFC protocols: ECMA-340, ECMA-352, ISO/IEC 14443, ISO/IEC 15693, ISO/IEC 18000-3, ISO/IEC 18092, and ISO/IEC 21481, all of which are incorporated by reference herein in their entirety and for all purposes.
  • NFC Type 5 can use a Manchester encoding modulation scheme along with load modulation.
  • the main principle behind Manchester code is encoding 1s and 0s as a part of transitions, not static values. For example, instead of a 1 and 0 being encoded as a high and low (e.g., high and low voltage levels, first and second states), they are encoded as the transition from high (e.g., a first state) to low (e.g., a second state) and vice versa.
  • This modulation scheme mitigates the issue of loss of clock synchronization as every bit has a transition.
  • the at least one processor or circuit can vary or change the impedance of the inductive IMD coil 202 (e.g., load impedance) to change the power level or strength of the signal corresponding to data values in the encoded pressure data.
  • the transition of the impedance e.g., load impedance, impedance of the inductive IMD coil 202
  • the transition of the impedance from the first state to the second state corresponds to a logical one in the encoded pressure data and the transition of the impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data.
  • serial encoding can be applied to the digital pressure data.
  • the integrated circuit 204 can optionally, in some embodiments, include the C/D converter 212 configured to measure the capacitance of the capacitive element 206 and generate digital pressure data based on the capacitance of the capacitive 15694WOO1 (013-0615PCT1) 59 PATENT element 206.
  • the integrated circuit 204 can further include at least one of a processor or circuit configured to modulate the return NFC signal, to be transmitted by the coil 202, based on the digital pressure data.
  • Calibration Information [00239]
  • the integrated circuit 204 can store information including, but not limited to, calibration information 244, baseline information 258, patient information and a UID 242.
  • the calibration information 244 (e.g., coefficient values and offsets due to temperature and dielectric effect) is specific to the MEMS capacitive element 206 and can be obtained and programed into the IMD 150 during manufacturing. This calibration and serial number information can be encrypted and read by the external device 104 when required. Additionally, since the IMD 150 (e.g., integrated circuit 204) will contain unique identifiers programmed into the integrated circuit 204, multiple sensors/IMDs 150 placed in various locations to capture more than a single hemodynamic parameter will be capable of being interrogated and measured.
  • FIG. 1A the IMD 150 shown in Figure 1A, implanted within the pulmonary artery, and a sensor (not shown) in Figure 1B, implanted within the aorta, can be interrogated simultaneously, as the external device 104 can distinguish the source of the data based on unique identifier(s).
  • An exemplary method for calibrating the pressure sensor is discussed in Figure 5.
  • Pressure Sensor Packaging [00240]
  • Figures 4A–4K show embodiments illustrating the positioning of the integrated circuit 204 within the IMD 150 as well as how the integrated circuit 204 can be connected within the assembly.
  • FIG. 4A shows a top view of the IMD 150 (e.g., implantable pressure sensor) that includes the integrated circuit 204 that is communicates with and is preferably powered by the external device 104 using NFC in accordance with embodiments herein.
  • the overall size of the IMD 150 is limited to being able to be delivered via a 12F-14F catheter.
  • the IMD 150 includes inductive IMD coil 402 (also referred to as inductive NFC coil and inductive IMD coil 202 herein), the integrated circuit 204, and the MEMS capacitive element 206 (the electrode 211 is shown).
  • capacitor traces 408, 410 are interconnected with, via wire bond, the integrated circuit 204, and to the electrodes 207, 209 (not shown) located at the other end of the capacitor traces 408, 410.
  • a top glass 412 extends over the housing and the components, and the assembly is hermetically sealed.
  • Holes 413a, 413b, 413c, 413d extend through the glass 412 and the body of the IMD 150.
  • fastening element(s) such as anchor loops can utilize one or more of the holes 413 to removably fasten the IMD 150 to the delivery catheter.
  • a cavity 422 is formed between outer side surfaces 428 of the pedestal 416 and inner side surfaces 430 of the sensor body 414.
  • the cavity 422 accommodates the inductive IMD coil 402 between the outer side surfaces 428 of the pedestal 416 and the inner side surfaces 430 of the sensor body 414.
  • the cavity 422 is designed to fit in a sufficiently large inductive coil, the inductive IMD coil 402, with sufficient turns and wire gauge width to maximize the link for NFC communication up to six inches.
  • the cavity 422 supports the telemetry inductor and allows room for the integrated circuit 204, while minimizing any potential impact to construction of the IMD 150 and sensor drift.
  • a distal end 432 of the pedestal 416 is rounded and extends toward a distal end 424 of the sensor body 414.
  • a proximal end 434 of the pedestal 416 extends toward a proximal end 426 of the sensor body 414 and is squared-off or forms a mostly flat vertical surface having a width 460 between beveled edges of the pedestal 416 that are proximate the outer side surface 428.
  • the pedestal 416 has a height 462 extending from a top surface of the pedestal 416 the floor of the cavity 422, a maximum width 463, and a maximum length 465.
  • Laser stripping can be used to remove the insulation from the wires to form the coil terminals 404, 406, and the coil terminals 404, 406 will be bonded to the ASIC chip gold electrode pads.
  • the long-term stability (e.g., not drifting over time) of the IMD 150 is preferably considered when choosing materials. Selecting suitable materials for use in the IMD 150 involves multiple considerations, such as the unique properties of each material, their behavior under processing conditions, and their performance in the final application.
  • the material stability, mechanical stability, and bonding integrity e.g., inductive IMD coil 402 to the chip pads or integrated circuit 204 to the fused silica
  • inductive IMD coil 402 present challenging requirements, as both the adhesive(s) and inductive IMD coil 402 in the long term will impact the device drift behavior. Additionally, maintaining the vacuum inside the IMD 150 after processing will lead to better functional performance of the device.
  • 15694WOO1 (013-0615PCT1) 63 PATENT [00251] Turning first to the inductive IMD coil 402, a non-limiting list of considerations comparing copper vs. gold properties is provided: [00252] (1) Electrical Conductivity: Copper has excellent electrical conductivity, making it ideal for efficient electrical signal transmission in coils.
  • Gold is significantly more expensive than copper.
  • (6) Wedge Bonding to Gold Electrode Pads Gold wires are more compatible with gold pads in terms of bonding, while copper wires are less reliable due to intermetallic compound formation in bonding to gold pads. Copper-to-gold bonding has a very narrow window for processing parameters compared to gold- to-gold bonding.
  • a list of adhesives that may be considered for use within the IMD 150 include, but are not limited to, i) UV-Curing Epoxy Adhesive: Master Bond UV25, ii) Epoxy Adhesive: Master Bond Supreme 17HT, iii) Epoxy Adhesive: Master Bond Supreme 121AO, iv) Silicone Adhesive: NuSil-CV1-1142, v) Silicone Adhesive: NuSil MED3-4213, vi) Polyimide: PI 2611, and vii) Epoxy Adhesive: Master Bond Supreme 3HTND-2DA.
  • the coil terminals 404 and 406 of the coil 402 are wirebonded to terminals 452 and 454, respectively, of the integrated circuit 204.
  • Connector 472 extends between and is wirebonded or otherwise attached directly to a proximal end of the capacitor trace 408 and terminal 456 of the integrated circuit 204.
  • Connector 474 extends between and is wirebonded or otherwise attached directly to a proximal end of the capacitor trace 410 and terminal 458 of the integrated circuit 204.
  • the connectors 472 and 474 can be gold, gold plated, contain gold, etc. It should be understood that the location of the terminals 452–458 may vary based on the design of the integrated circuit 204.
  • the width 444 of the integrated circuit 204 is approximately the same as the width 460 of the proximal end 434 of the pedestal 416, and the height 462 of the pedestal 416 is slightly greater than the height 446 of the integrated circuit 204.
  • a distal side of the integrated circuit 204 can sit flush against the proximal end 434 of the pedestal 416, between beveled edges 464 and 466.
  • Open area 468 of the cavity 422 extends between a proximal side 470 of the integrated circuit 204 and the inductive IMD coil 402.
  • FIGS 4G and 4H illustrate views wherein the integrated circuit 204 is mounted to PCB 482 in accordance with embodiments herein.
  • the coil terminals 404 and 406 of the inductive IMD coil 402 are tab welded to pads 484 and 486, respectively, of the PCB 482.
  • Interconnect tab 473 is attached at a proximal end of the capacitor trace 408 and tab welded to pad 488 of the PCB 482.
  • Interconnect tab 475 is attached to a proximal end of the capacitor trace 410 and tab welded to pad 490 of the PCB 482.
  • the interconnect tabs 473, 475 can be formed of gold, be gold plated, etc.
  • the pads 488, 490, 484, 486 can be gold plated.
  • the interconnect tabs 473, 375 can be welded to pads on the integrated circuit 204.
  • the pads can be 488, 490, 484, 486 can be attached to a surface of the integrated circuit 204 instead of to an intermediary PCB 482.
  • Figure 4K illustrates an exploded view of the implantable IMD coil 402 and sensor body 414 wherein the integrated circuit 204 (not shown) is mounted to the bottom side of the PCB 482 in accordance with embodiments herein.
  • the coil terminals 404 and 406 are connected to the pads 484 and 486, respectively, of the PCB 482 as discussed in Figure 4G.
  • the assembly that includes the PCB 482, the integrated circuit 204, and the power/energy storage capacitor 476 (if used) are interconnected with the coil 402 in advance of mounting the implantable IMD coil 402 within the cavity 422.
  • the integrated circuit 204 is attached to the pedestal 416 with the adhesive layer 499.
  • Figure 4L shows a cross-sectional view of the IMD 150 (e.g., implantable pressure sensor) in accordance with embodiments herein. Portions of the implantable IMD coil 402 can be seen at either end.
  • the integrated circuit 204 15694WOO1 (013-0615PCT1) 68 PATENT is mounted to the pedestal 416 with the adhesive layer 499.
  • the gold interconnect tab 475 is indicated, directly connecting the capacitor trace 408 (not shown) to the integrated circuit 204.
  • Figure 4M is a top view showing the interconnect tabs 473, 475 directly attaching to the integrated circuit 204 of the IMD 150 (e.g., implantable pressure sensor) in accordance with embodiments herein.
  • the elements are described in further detail in the other illustrations.
  • the NFC reader e.g., external device 104
  • the external device 104 is designed to be sensitive to pick up the load modulated signal from the IMD 150.
  • the external device 104 includes adaptive power control, where only the necessary amount of power is provided to the IMD 150 to mitigate concerns of overheating the IMD 150 than may result in inaccurate readings.
  • Adaptive power control is based on receive signal strength indicator (RSSI) measurements.
  • RSSI receive signal strength indicator
  • an RSSI measurement may also be accomplished by the IMD 150 to measure the amount of power that it receives.
  • the adaptive power control sequence can start with the external device 104 starting at a low power output and gradually ramping the power output up until the external device 104 receives a response back from the IMD 150.
  • RSSI received signal strength indicator
  • the external device 104 can assess the RSSI and adjust the power accordingly based on a predetermined time period, number of communication packet exchanges, etc.
  • the system can operate in a request-response mode. At least 100 samples/second are achieved.
  • the external device 104 can request one sample at a time, or in other embodiments, samples can be buffered by the integrated circuit 204 so that multiple samples are sent with each request.
  • the NFC transmission generated by the NFC block 216 of the integrated circuit 204 follows the NFC protocol and will include pressure data, unique identifier (UID) 242 (e.g., serial number), and Cyclic Redundancy Check (CRC) (e.g., error detection).
  • UID unique identifier
  • CRC Cyclic Redundancy Check
  • the external device 104 can utilize NFC to energize and receive communications simultaneously from multiple IMDs 150, 152 as each IMD 150, 152 has a UID 242.
  • the external device 104 can also communicate with other IMDs within the body that use NFC and may have their own power source.
  • the external device 104 can identify the source of the received data based on the UID.
  • the pressure measurement is accomplished while NFC power is applied by the external device 104 as there is no power storage on the IMD 150 (e.g., implantable pressure sensor).
  • the IMD 150 e.g., implantable pressure sensor
  • FIG. 5 illustrates an example process flow for calibrating the IMD 150 (e.g., implantable pressure sensor) in accordance with embodiments herein. This process may be accomplished during manufacturing, such as after the IMD 150 is fully assembled and in advance of the IMD 150 being allocated to a patient.
  • IMD 150 e.g., implantable pressure sensor
  • the operations of Figure 5 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server, local computer, or more generally within a health care system.
  • the operations of Figure 5 may be partially implemented by the IMD 150 and partially implemented by another processing device and/or system. It should be recognized that while the operations of Figure 5 are described in a somewhat serial manner, one or more of the operations may be continuous and/or performed in parallel with one another.
  • one or more processors or circuits direct an external device 104 to transmit an energizing NFC signal.
  • the coil transmitting the NFC may be within six inches of the IMD 150.
  • the inductive IMD coil 202 is energized and the resonant capacitor resonates with the inductive IMD coil 202.
  • the one or more processors or circuits measure/determine the resonant frequency of the resonant capacitor.
  • the one or more processors or circuits determine whether the resonant frequency of the resonant capacitor is within an ideal resonance, such as within a predetermined range of 13.56 MHz.
  • the process flows to 508 and the one or more processors or circuits adjust the capacitance by, for example, programmably wiring trim bits (e.g., different 15694WOO1 (013-0615PCT1) 71 PATENT capacitors in an array) in or out of the circuit.
  • trim bits e.g., different 15694WOO1 (013-0615PCT1) 71 PATENT capacitors in an array
  • the swapping in or out of the capacitors in the array is controlled by switches that are closed or opened based on the trim bits. For example, in some cases, coarse trim bits (controlling larger capacitors) may be adjusted/swapped first for larger capacitance change. After the resonant frequency is remeasured, the resonant capacitor can be fine-tuned with finer trim bits (controlling smaller capacitors).
  • the process returns to 508 to evaluate the resonant frequency of the resonant capacitor.
  • the process flows to 510 and the one or more processors or circuits pressurize the IMD 150.
  • the IMD 150 may be placed within a pressure chamber capable of increasing and decreasing pressure at a predetermined rate and/or in a stepped fashion over a predetermined pressure range.
  • the one or more processors or circuits determine the capacitance of the MEMS capacitive element 206 at the particular pressure and convert the capacitance to a digital word, such as with the capacitance to digital converter.
  • the one or more processors or circuits fit a second order polynomial to the capacitance versus pressure relation to determine coefficient values and offsets, generally referred to as calibration 15694WOO1 (013-0615PCT1) 72 PATENT information. These coefficient values and offsets can be due to temperature and dielectric effect.
  • the one or more processors or circuits transmit the calibration information via NFC from the external device 104 to the NFC block 216, and the NFC block 216 directs the memory 210 to store the calibration information 244.
  • the calibration information 244 will only be written once; however, the integrated circuit 204, in other embodiments, allows for up to five writes, either through rewritable memory or by using five times the amount of OTP memory.
  • the IMD 150 may be recalibrated to compensate for changes in aging components.
  • the one or more processors or circuits write the unique serial number or other identifier(s) to the memory 210 of the integrated circuit 204.
  • Implanting the Pressure Sensor [00296]
  • Figure 6 illustrates an example process flow for identifying and baselining the IMD 150 (e.g., implantable pressure sensor) during implantation in accordance with embodiments herein.
  • the operations of Figure 6 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system.
  • the operations of Figure 6 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 6 are described in a somewhat serial manner, one or more of the operations may be continuous and/or performed in parallel with one another.
  • the IMD 150 is placed near the external device 104. In some embodiments, the maximum temperature range for this operation is 5 to 40 degrees Celsius.
  • one or more processors or circuits direct the external device 104 to transmit NFC signal to energize the IMD 150.
  • the one or more processors or circuits transmit a message over NFC to request that the integrated circuit 204 transmit the serial number.
  • the one or more processors or circuits such as of the NFC block 216, generate and send an information request 238 to the memory 210.
  • the one or more processors or circuits access the UID 242 (e.g., serial number) stored within the memory 210 and return the UID 242 (e.g., serial number) via the requested information 240.
  • the one or more processors or circuits such as of the NFC block 216, prepare and transmit a message over NFC to send the UID 242 (e.g., serial number) to the external device 104.
  • the NFC block 216 can build the packets including calibration information 244, UID 242, and/or other identifying information.
  • readings can be acquired from a pressure catheter (e.g., right heart catheter) to detect pressure. In some embodiments, the pressure can be measured using components included in the delivery catheter.
  • the pressure detected by the IMD 150 is compared to the pressure detected by the pressure catheter. 15694WOO1 (013-0615PCT1) 74 PATENT [00306] If a difference is determined between the two pressure measurements at 618, at 620 an offset to the baseline information is determined.
  • the one or more processors or circuits accept the baseline offset and modify the baseline information.
  • the offset may be determined and entered manually at the external device. Additionally, or alternatively, pressure measurements from a catheter may be electronically conveyed/transmitted to the external device which then automatically calculates the offset.
  • the one or more processors or circuits transmit the baseline information, via NFC, to the integrated circuit 204.
  • the one or more processors or circuits such as of the NFC block 216, direct the memory 210 to save the baseline information 258.
  • the one or more processors or circuits transmit a patient identifier, via NFC, to the integrated circuit 204, and the one or more processors or circuits direct the memory 210 to save the patient identifier.
  • a patient identification (ID) number, social security number, etc. may be entered into the external device 104 via a graphical user interface and/or received electronically and saved. This may, for example, be used to ensure that the collected data is assigned to the correct patient, as well as assist with the correlation of data if multiple IMDs 150 are implanted.
  • the physician may choose to insert a pressure catheter to re-baseline the sensor.
  • FIG. 7 illustrates an example process flow for acquiring pressure readings sensed by the IMD 150 (e.g., implantable pressure sensor) in accordance with embodiments herein.
  • the operations of Figure 7 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system.
  • the operations of Figure 7 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 7 are described in a somewhat serial manner, one or more of the operations may be continuous and/or performed in parallel with one another.
  • Figure 7 is discussed together with Figures 1A, 1B, and 3. [00313]
  • the external device 104 is positioned near or in contact with the patient and also near the implanted location of the IMD 150.
  • the patient may be instructed by a clinician where along their torso to position the external device 104.
  • the external device 104 may be a pillow, blanket, belt, or included within another garment, be comprised of more than one piece wherein the coil or antenna is held within a portion close to the patient and interconnected with a computer, phone, base station, and/or other external device.
  • the patient may have more than one implanted pressure sensor that can be sensed with the external device 104 positioned in one place.
  • the patient may be instructed to move the external device 104 to one or more other location proximate their body to read other implantable pressure sensors.
  • one or more processors or circuits direct the external device 104 to transmit NFC signal to energize the IMD 150.
  • the patient may select an option, such as through a graphical user interface (GUI), to direct the external device 104 to take the pressure reading.
  • GUI graphical user interface
  • the external device 104 can respond, for example, to a selection via a keyboard or GUI, a voice command, a command received via an external device such as an application on a patient’s phone, a command received via the internet such as from a clinician, and/or responsive to a preset time.
  • the one or more processors or circuits such as of the NFC block 216, transmit a measurement request 254 to the C/D converter 212.
  • the one or more processors or circuits can also transmit an information request 238 to the memory 210, requesting the UID 242, calibration information 244, baseline information 258, as well as any other identification information such as a patient ID.
  • the one or more processors or circuits determine the capacitance of the MEMS capacitive element 206 and convert the capacitance to a digital word, such as with the C/D converter 212. [00318] At 710, the one or more processors or circuits transmit the pressure data 256 to the NFC block 216. [00319] At 712, the one or more processors or circuits transmit the UID 242 (e.g., serial number) and calibration information 244 from the memory 210 to the NFC block 216 via requested information 240.
  • UID 242 e.g., serial number
  • the one or more processors or circuits prepare a packet or payload of data including the pressure data 256 and the requested information 240 (e.g., UID 242 and calibration information 244) to send to the external device 104 using NFC.
  • the packet of data can be encoded to form encoded pressure data, preferably including an error bit and encrypted.
  • 15694WOO1 (013-0615PCT1) 77 PATENT
  • the one or more processors or circuits use NFC telemetry 252, to transmit the packet using NFC.
  • a plurality of packets can be transmitted in a burst.
  • the one or more processors or circuits receive the packet at the external device 104.
  • the packet can be stored in a memory on the external device 104 until manually deleted, for a predetermined period of time, until transmitted to an external health system, and the like.
  • the one or more processors or circuits determine whether more data is to be collected. For example, a typical reading or collection session can be 18 seconds of data captured at 100 Hz (or 250 Hz). Other lengths of time and frequency is contemplated. [00324] If more data is to be collected, the process returns to 706.
  • the process of determining the capacitance of the MEMS capacitive element 206, converting it to a digital word, and transmitting the data over NFC to the external device 104 occurs thousands of times during the typical reading.
  • the capacitance value can be sampled at a specified sampling frequency without a break in time until the time duration (e.g., 18 seconds) is reached.
  • the process flows to 722.
  • the one or more processors or circuits may direct the patient to move the external device 104 to the next location.
  • the one or more processors or circuits transmit the pressure data from the external device 104 to a healthcare system, such as to an electronic location accessible by a clinician associated with the patient.
  • the patient may take one reading a day.
  • patients may find it easy to take multiple 15694WOO1 (013-0615PCT1) 78 PATENT readings a data. This increase in data collection can result in improved disease and symptom tracking, diagnosis, and recommendations for treatment.
  • the pressure data can be correlated with time the patient takes a medication.
  • FIG. 8 illustrates a digital healthcare system 800 implemented in accordance with embodiments herein.
  • the system 800 utilizes signals detected by an IMD and/or an IPS, implanted for example in a patient’s pulmonary artery and/or other vessel, to determine pressures, arrythmia, valid/invalid heartbeats of a patient, etc.
  • the healthcare system 800 may include wearable devices that communicate with an IMD, IPS, external device, and/or a remote database.
  • the healthcare system 800 may monitor health parameters of a patient, including blood pressure, valid heartbeats, heart rate, HRV, cardiac output, and/or therapies applied utilizing the health parameters, and provide a diagnosis and/or recommendations for the patient based on the monitored health parameters, adjust treatment parameters, etc.
  • the system 800 may be implemented with various architectures, that are collectively referred to as a healthcare system 820.
  • the healthcare system 820 may be implemented as described herein.
  • the healthcare system 820 may be a patient care network, such as the Merlin.net TM patient care network operated by Abbott Laboratories (headquartered in the Abbott Park Business Center in Lake Bluff, Ill.) [00330]
  • the healthcare system 820 is configured to receive data, including IMD data from a variety of external and implantable sources including, but not limited to, active IMDs 802 capable of delivering therapy to a patient, passive IMDs 804 (e.g., cardiac monitors, IPS) capable of generating data associated with a patient, wearable devices/sensors 808, and point-of-care (POC) devices 810 (e.g., at home or at a medical facility).
  • active IMDs 802 capable of delivering therapy to a patient
  • passive IMDs 804 e.g., cardiac monitors, IPS
  • wearable devices/sensors 808 capable of generating data associated with a patient
  • POC point-of-care
  • FIG. 9A illustrates a system 200 wherein the external device 104 uses NFC to communicate with and preferably power the IMD 150 in accordance with embodiments herein.
  • the system 200 shows some of the components of the IMD 150 and the external device 104.
  • the IMD 150 is an implantable pressure sensor.
  • the IMD 150 can be a different type of implantable device.
  • the terms coil and antenna are herein used interchangeably.
  • the IMD 150 includes the inductive IMD coil 202 (e.g., antenna) for communications and power transfer, the integrated circuit 204 (e.g., ASIC), and the Micro-Electromechanical Systems (MEMS) capacitive element 206 for use as a pressure transducer.
  • MEMS Micro-Electromechanical Systems
  • the integrated circuit 204 further includes the IMD transceiver 208, memory 210, and, preferably the capacitance to digital (C/D) converter 212.
  • an IMD tunable matching network 205 is coupled between the IMD inductive IMD coil 202 and the integrated circuit 204.
  • the IMD tunable matching network 205 can be included on the integrated circuit 204, while in other embodiments, the IMD tunable matching network 205 can be located outside the integrated circuit 204.
  • the IMD tunable matching network 205 can be preferably dynamically tuned as the IMD 150 communicates bidirectionally with the external device 104.
  • the IMD tunable matching network 205 can be initially optimized 15694WOO1 (013-0615PCT1) 80 PATENT during manufacturing using switches and/or adjustable components. Then, when installed in the body, the IMD tunable matching network 205 can continue to be optimized using switches and/or adjustable components to create different IMD matching network configurations.
  • the memory 210 is a tangible and non-transitory computer-readable storage medium. In addition to the information stored as discussed above, the memory 210 can further store information related to tuning the IMD tunable matching network 205, such as thresholds, search ranges, time intervals, etc.
  • the external device 104 can be configured to direct the integrated circuit 204 to store information in the memory 210.
  • the external device 104 may direct the integrated circuit 204 to store calibration information, baseline information, and the like.
  • the external device 104 can also be used to store new and/or updated calibration and/or baseline information at a later date, such as during another procedure or during an office visit.
  • the external device 104 may also be capable of storing information related to tuning the inductive IMD coil 202, such as thresholds, search ranges, time intervals, etc.
  • an external device 104 may be designed for the patient to be used at home and may not have the capability to direct the integrated circuit 204 to write to the memory 210.
  • the external device 104 includes an inductive external coil 231 and an external transceiver 235 (e.g., capable of transmitting and/or receiving NFC).
  • an external tunable matching network 233 is coupled between the inductive external coil 231 and the external transceiver 235.
  • the external tunable matching network 233 can preferably be dynamically tuned as the external device 104 establishes communication with, and communicates bidirectionally with, the IMD 150.
  • the external tunable 15694WOO1 (013-0615PCT1) 81 PATENT matching network 233 can be optimized using switches and/or adjustable components to create different external matching network configurations.
  • the inductive external coil 231 communicatively connected to the external device 104 may be designed with a size to generate a larger field, such as to ensure communication of up to six inches deep within the patient’s body.
  • External coil dimensions of at least 4” to 12” e.g., 10.16 cm to 30.48 cm
  • the inductive external coil 231 can either be embedded in a pillow or blanket to be positioned underneath or on top of the patient, or embedded in other concepts like a sash, belt, or garment.
  • the external antenna/coil dimensions can be larger than 12” (e.g., 30.48 cm).
  • At least some components of the inductive external coil 231 can be conformable and/or flexible to better match contours of the patient, improving transmission between the external device 104 and the IMD 150.
  • the inductive external coil 231 may be connected to but housed separately from one or more other components of the external device 104.
  • the IMD 150 includes a housing 214 that holds and encapsulates the components including the inductive IMD coil 202, the IMD tunable matching network 205, the integrated circuit 204, and MEMS capacitive element 206 to protect these components from the harsh organic environment of the body.
  • the housing 214 may be hermetically sealed.
  • the MEMS capacitive element 206 is an example and represents only one implantable sensor that may be used together with the new and unique aspects discussed herein.
  • Figure 9B illustrates a block diagram of the preferable integrated circuit 204 in accordance with embodiments herein. Some components of Figure 9B are discussed above with respect to Figure 3A and are not further discussed in this section.
  • the NFC block 216 is interconnected to the inductive IMD coil 202 (e.g., antenna) / IMD tunable matching network 205 via connections 228, 230.
  • the NFC block 216 preferably includes power harvesting 248 to collect energy from the transmitted NFC and provide power to the power regulation block 220 via connection 232, which in turn can power the memory 210 via connection 234, the C/D converter 212 via connection 236, and temperature sensor 218 via connection 237.
  • the temperature sensor 218 can monitor the temperature over a time period (e.g., 18 seconds, 30 seconds) that the integrated circuit 204 is expected to be powered during normal use to allow adjustments in the calibration, capacitance trimming, configuration of the IMD tunable matching network 205, etc.
  • hard coded logic e.g., circuit, circuitry
  • the NFC block 216 includes and/or is in communication with one or more preferred processor 246 incorporated within the integrated circuit 204 that includes program instructions and is configured to accomplish requests, receive data, output data via NFC, and the like.
  • the NFC block 216 can further include a preferred IMD receive signal strength indicator (RSSI) determination module 269 that can determine an IMD RSSI, which can be a measure of the strength or power of the NFC signal received by the IMD 150, typically measured in decibels (dB).
  • RSSI receive signal strength indicator
  • the IMD RSSI determination module 269 can be in communication with and receive 15694WOO1 (013-0615PCT1) 83 PATENT instructions from the processor 246.
  • the NFC block 216 can receive instructions within an NFC packet transmitted from the external device 104 requesting that the IMD RSSI determination module 269 determine the IMD RSSI.
  • the IMD RSSI can be included in an NFC packet (e.g., data packet) and transmitted to the external device 104.
  • the NFC block 216 can also include a preferred IMD matching network configuration module 271.
  • the IMD matching network configuration module 271 can be in communication with and receive instruction from the processor 246.
  • the IMD matching network configuration module 271 can control switches and/or adjustable components of the IMD tunable matching network 205 to change the configuration of the IMD tunable matching network 205 and dynamically tune the antenna/coil 202.
  • the IMD matching network configuration module 271 can adjust adjustable components that can change capacitance, inductance, and/or resistance, and/or vary voltage such as to change the capacitance of varactor(s).
  • the NFC block 216 can include a preferred IMD phase difference determination module 273.
  • the IMD phase difference determination module 273 can determine the phase difference between the transmit (e.g., IMD 150) and receive (e.g., external device 104) signals.
  • the IMD phase difference determination module 273 can initiate tuning of one or both of the external tunable matching network 233 and the IMD tunable matching network 205. In some embodiments, the IMD phase difference determination module 273 can monitor the phase difference at predetermined time intervals, and/or as part of another process. [00345] In some embodiments, the at least one processor 246 or circuit of the integrated circuit 204 provides the ability to trim or configure the IMD tunable matching network 205 to optimize it for the NFC frequency.
  • the IMD 15694WOO1 (013-0615PCT1) 84 PATENT tunable matching network 205 can include a resonant capacitor that resonates with the coil 202; however, manufacturing and assembly variability may result in frequency variations. In some cases, it is desirable to trim the resonant capacitor so that it resonates at the NFC frequency of 13.56 MHz.
  • the NFC block 216 can have an on-chip resonant capacitor as well as the ability to trim the capacitor (shown collectively as IMD tunable matching network 205).
  • an array of capacitors can be wired in or out of circuit via trim bits. The trim bits can be programmable via the NFC interface and powering, ideally when the IMD 150 is fully packaged.
  • the telemetry controls the trimming (e.g., tells which trim bits to enable/disable) and the NFC powering provides the power needed to write into the memory 210.
  • the trim bits are programmed before the IMD 150 is implanted within a patient, such as during a factory process.
  • the NFC block 216 can “wake up” and preferably send a measurement request 254 to the C/D converter 212.
  • the C/D converter 212 powered by the power regulation block 220, converts the capacitance into a digital word that represents the pressure within the area around the MEMS capacitive element 206 at the particular point in time.
  • the pressure data is sent to the NFC block 216 for encoding (e.g., adding information such as error bit) to form encoded pressure data.
  • the encoded pressure data may further be encrypted (e.g., encryption 250).
  • the encoded and/or encrypted pressure data is then utilized to modulate the return signal. Encoding and encryption are further discussed herein above.
  • the pressure data along with data that identifies the IMD 150, the IMD RSSI, the IMD output frequency, the IMD matching network configuration, temperature data, etc., can be transmitted to the external device 104, such as in one or more packets.
  • Figure 9C illustrates an exemplary external device 104 for communicating with an IMD 150 implanted within a body in accordance with embodiments herein.
  • the IMD 150 can be one of the sensors discussed with respect to Figure 1A and/or another implanted sensor/device capable of NFC.
  • the NFC reader e.g., external device 104
  • the external device 104 is designed to be sensitive to pick up the load modulated signal from the IMD 150.
  • the external device 104 is positioned outside of the patient.
  • the external device 104 may have components configured to interface with and/or contact skin and/or clothing of the patient, such as a pillow, garment, and the like.
  • the inductive external coil 231 e.g., antenna
  • the inductive external coil 231 and/or external tunable matching network 233 can be conformable, i.e., components of the inductive external coil 231 and/or external tunable matching network 233 may flex, bend, and the like to conform to the patient.
  • the external device 104 is capable of communicating (e.g., communications circuit 950) with other external device(s) 952, such as smart phones, cellular phones, watches, computers, laptops, tablets, programmers, etc., as well as communicating wirelessly and over wired communication technologies to convey/transmit information between remote servers, computers, etc.
  • other external device(s) 952 such as smart phones, cellular phones, watches, computers, laptops, tablets, programmers, etc.
  • the external device 104 can include a programmable microcontroller 954 and/or other processor(s) and/or circuit(s) that controls various operations, including communicating with one or more IMDs 150, configuring the external tunable matching network 233, directing one or more IMD 150 to configure the IMD 15694WOO1 (013-0615PCT1) 86 PATENT 150 tunable matching network 205, and cardiac monitoring such as monitoring blood pressure.
  • the microcontroller 954 can include a microprocessor (or equivalent control circuitry, one or more processors, etc.), RAM and/or ROM memory, logic and timing circuitry, state machine circuitry, I/O circuitry, ASIC, and the like.
  • the inductive external coil 231 can power the IMD 150 and convey/transmit the external NFC signals to the IMD 150.
  • the external device 104 also includes the external transceiver 235 ( Figure 9A) that is capable of transmitting the external NFC signals having relatively different power levels, and receiving the NFC signals via the inductive external coil 231 that include IMD NFC signals, such as from the IMD 150.
  • the external transceiver 235 can simultaneously power multiple IMDs, and transmit and receive NFC signals to and from multiple IMDs.
  • the external device 104 can also include an emission or output power level adjustment module 956 for selecting an output power of the external NFC signals.
  • the output power level adjustment module 956 can set an emission level to a relatively lower setting while initiating communication with an IMD 150.
  • the output power level adjustment module 956 can increase the power up to a maximum power threshold (e.g., ramp up) until communication is established.
  • a power threshold may be set at 7 W, 8 W, 10 W, etc.
  • the output power level adjustment module 956 can increase/decrease the output power in several ways. Non-limiting examples include directing an amplifier (e.g., adjust a gain adjustment), which may be included in the external transceiver 235, the inductive external coil 231, or elsewhere within the external device 104 to increase/decrease the output power and/or increase/decrease a current input power to the amplifier.
  • the external device 104 when initiating communication with the IMD 150, can start at a low level of power output and gradually ramp up the power until communication is reached. In some cases, the power 15694WOO1 (013-0615PCT1) 87 PATENT output may be increased slightly beyond this level to ensure enough margin. As an example, the external device 104 can start at 100 mW, then step up in 100-250 mW increments until successful communication occurs. If successful communication occurs at 2 W, the RSSI (received signal strength indicator) of the IMD 150 may be, for example, 1 mW. The external device 104 can then increase the power output to, for example, 2.5 W, to ensure enough margin.
  • the power 15694WOO1 (013-0615PCT1) 87 PATENT output may be increased slightly beyond this level to ensure enough margin.
  • the external device 104 can start at 100 mW, then step up in 100-250 mW increments until successful communication occurs. If successful communication occurs at 2 W, the RSSI (received signal strength
  • the RSSI of the IMD 150 will also increase, such as to 5 mW.
  • the external device 104 and IMD 150 may begin the telemetry/measurement process.
  • the RSSI of the IMD 150 can be monitored so that if the RSSI increases too much, such as above a maximum threshold, the power output of the external device 104 can be decreased. If, however, the RSSI falls below a lower threshold, such as below 2 mW, the output power can be increased, such as to approximately 3 W, to return to an RSSI of approximately 5 mW.
  • An output power determination module 958 can compare the output power to the power threshold, such as at time intervals set by a timer, based on a trigger, and/or as part of another process.
  • the external device 104 can include an RSSI determination module 960.
  • monitoring the IMD RSSI and/or external RSSI can be referred to as adaptive power control, wherein only the necessary amount of power is provided to the IMD 150 to mitigate concerns of overheating the IMD 150 that may result in inaccurate readings.
  • Adaptive power control can also be used to ensure maximum power transfer.
  • Adaptive power control is based on RSSI measurements.
  • the external RSSI measurements can be accomplished by the external device 104, which measures the strength of the signal it receives back from the IMD 150. In some cases, the closer the IMD 150 is to the external device 104, the larger the signal that is reflected back.
  • an IMD RSSI measurement may also be accomplished by the IMD 150 (e.g., IMD RSSI determination module 269 of Figure 9B) to measure the amount of power that it receives.
  • the IMD RSSI can be transmitted to the external device 104.
  • the IMD 150 can compare the IMD RSSI to an IMD RSSI threshold and if the threshold is satisfied (e.g., met, exceeded), the IMD 150 can send a request to the external device 104 to lower the output power.
  • the adaptive power control sequence can start with the external device 104 starting at a low power output and gradually ramping the power output up until the external device 104 receives a response back from the IMD 150. Once the external device 104 receives a response back, it can determine the external RSSI.
  • the power level can be referred to as a characteristic of interest (COI). If the external RSSI is too high, such as compared to a predetermined threshold, the external device 104 can reduce the power output (e.g., output power level 15694WOO1 (013-0615PCT1) 89 PATENT adjustment module 956). If the external RSSI is low, such as compared to the predetermined threshold or a different second threshold, then the external device 104 can increase the power.
  • COI characteristic of interest
  • the external device 104 can assess the external RSSI and adjust the power accordingly. In other embodiments, the external device 104 can assess the external RSSI and/or IMD RSSI and adjust the power accordingly based on a predetermined time period, number of communication packet exchanges, a trigger, etc. [00359] In some embodiments, the external device 104 can include a reflection coefficient module 962. For example, the external device 104 can determine a voltage level of and/or associated with IMD NFC signals returned from the IMD 150 and a voltage level of and/or associated with the external NFC signals transmitted by the external device 104. The voltage level can be referred to as a characteristic of interest (COI).
  • COI characteristic of interest
  • the reflection coefficient can be determined as the ratio of the reflected wave (e.g., IMD NFC signals) to the incident wave (e.g., external NFC signals. It is desirable to minimize the reflection coefficient at the target frequency of 13.56 MHz.
  • a phase difference determination module 964 can determine the phase difference between the transmit (external device 104) and receive (IMD 150) signals. If the phase difference determination module 964 determines that the phase difference satisfies a threshold, such as being outside of a range, percentage, and/or number, the phase difference determination module 964 can initiate tuning one or both of the external tunable matching network 233 and the IMD tunable matching network 205.
  • the phase difference determination module 964 can monitor the phase difference at predetermined time intervals, as the result of a trigger, and/or as part of another process.
  • An IMD data determination module 966 can decode packets of information sent via the IMD NFC signals.
  • the external device 104 transmits the energizing external NFC signal, and receives, via IMD NFC signals, 15694WOO1 (013-0615PCT1) 90 PATENT packets that include the digitized capacitance information.
  • the NFC block 216 ( Figure 9B) can build the packets including calibration information 244, UID 242, and/or other identifying information, data measurements such as pressure, IMD RSSI, IMD output frequency, IMD matching network configuration, etc.
  • An external matching network configuration module 968 can direct the external tunable matching network 233 and/or the IMD tunable matching network 205 to change configuration.
  • the external matching network configuration module 968 can reconfigure the external tunable matching network 233 to “sweep” the range of the external tunable matching network 233 to adjust the impedance of the external coil 231.
  • the external matching network configuration module 968 can reconfigure the external tunable matching network 233 through an impedance range that is less than a total range, in different sized step increments (course or fine adjustments), etc.
  • the external matching network configuration module 968 can initiate a message to be included in a packet sent to the IMD 150 to direct the IMD 150 to reconfigure the IMD tunable matching network 205 according to certain parameters.
  • a memory 970 or other storage medium stores program instructions, settings, thresholds, ranges, IMD data measurements, signal data such as pressure, data received from the IMD 150, etc.
  • the external device 104 can perform a method for managing inductive communication between an IMD 150 and an external device 104, wherein the external device 104 has an inductive external coil 231 (e.g., external antenna) configured to be located proximate to a body and the IMD 150 is configured to be located within the body.
  • an inductive external coil 231 e.g., external antenna
  • the external device 104 transmits, by the inductive external coil 231, inductive external near field communication (NFC) signals to an inductive IMD coil 202 (e.g., IMD antenna).
  • the inductive external coil 231 receives inductive IMD NFC signals from the inductive IMD coil 202.
  • a characteristic of interest (COI) can be determined based on the inductive IMD NFC 15694WOO1 (013-0615PCT1) 91 PATENT signals, such as by but not limited to the RSSI determination module 960 and/or the reflection coefficient module 962.
  • the external device 104 can dynamically tune at least one of the inductive external coil 231 or the inductive IMD coil 202 based on the COI.
  • the inductive IMD NFC signals include IMD data measurements.
  • the COI is a voltage level of (or associated with) the IMD NFC signals, and the external device 104 can dynamically tune the inductive external coil 231 or the inductive IMD coil 202 based on a reflection coefficient of (associated with) the COI.
  • the COI is a voltage level of (associated with) the IMD NFC signals, and the external device 104 can dynamically tune the inductive external coil 231 by changing at least one parameter of an external tunable matching network 233 communicatively connected to the inductive external coil 231 to minimize a reflection coefficient associate with the COI.
  • Changing at least one parameter of the external tunable matching network 233 can comprise opening or closing one or more switches in the external tunable matching network, adjusting one or more adjustable components in the external tunable matching network 233, and/or increasing or decreasing an input voltage to the external tunable matching network to adjust an impedance of the inductive external coil 231.
  • the COI is an IMD received signal strength indicator (RSSI), and the COI is included in a data packet transmitted by the IMD coil.
  • RSSI received signal strength indicator
  • the method for managing inductive communication further includes determining an external RSSI of, based on, and/or associated with the inductive IMD NFC signals, and wherein the dynamically tuning further includes configuring a network configuration of an external tunable matching network 233 communicatively connected to the inductive external coil 231 or an IMD tunable 15694WOO1 (013-0615PCT1) 92 PATENT matching network 205 communicatively connected to the inductive IMD coil 202 to maximize one of the IMD RSSI or external RSSI.
  • the method for managing inductive communication further includes transmitting, by the inductive external coil 231, successive inductive external NFC signals to the inductive IMD coil 202, receiving, via the inductive external coil 231, successive inductive IMD NFC signals from the inductive IMD coil 202, the successive inductive IMD NFC signals including IMD data measurements, determining a successive COI based on the successive inductive IMD NFC signals, and the dynamically tuning further comprising dynamically tuning at least one of the inductive external coil 231 or the inductive IMD coil 202 based on the successive COI.
  • the external device 104 can set an output power of the inductive external coil 231 at an initial level, and in response to not receiving, via the inductive external coil 231, the IMD NFC signals from the inductive IMD coil 202, the output power level adjustment module can increase the output power of the inductive external coil 231.
  • the output power determination module can determine if an output power of the external device 104 satisfies a power threshold, and in response to the output power satisfying the power threshold, the output power level adjustment module 956 can decrease the output power.
  • the phase difference determination module can determine if a phase difference between the inductive external NFC signals of the inductive external coil 231 and the inductive IMD NFC signals of the inductive IMD coil 202 satisfies a phase difference threshold, and in response to the phase 15694WOO1 (013-0615PCT1) 93 PATENT difference satisfying the phase difference threshold, the external matching network configuration module 968 can change at least one parameter of an external tunable matching network 233 communicatively connected to the inductive external coil 231 or at least one parameter of an IMD tunable matching network 205 communicatively connected the inductive IMD coil 202.
  • the method further comprises evaluating i) an IMD RSSI, ii) an external RSSI, iii) a reflection coefficient of (associated with) the COI, iv) a phase difference between the inductive external NFC signals and the inductive IMD NFC signals, or v) an output power of the external device 104.
  • Matching Networks [00372] Figures 10A, 10B, 10C, and 10D illustrate examples of tunable matching networks that can be used with the inductive IMD coil 202 (e.g., IMD antenna) and/or the inductive external coil 231 (e.g., external antenna).
  • FIG. 10A a pi-network is illustrated
  • Figure 10B an L-match network is illustrated
  • Figure 10C a T-match network is shown
  • Figure 15694WOO1 (013-0615PCT1) 94 PATENT 10D
  • any combination of these antenna matching networks can be used, e.g., L-match, T- match, back-to-back Lmatch, such as by replicating one topology in series/parallel, multiple different networks in series/parallel, etc., and the arrangement of components is not limited to those shown and/or discussed.
  • any of the tunable matching networks in Figures 10A, 10B, 10C, and 10D can include more or less components, different components than shown, and components arranged in different configuration/order, including, but not limited to, switches, adjustable components, resistors, capacitors, inductors, and the like.
  • the components and changes to the tunable matching networks can be referred to as parameters, such that changing a parameter of the tunable matching network can include one or more of changing the position of a switch to include or exclude components, changing or adjusting the value of an adjustable component, and/or varying the level of input power to the tunable matching network.
  • the matching networks will include at least one switch, such that at least one component can be included or excluded from the circuit depending upon the position of the switch and/or adjusting the values of one or more adjustable components, resulting in at least two different matching network configurations.
  • one or more adjustable components can be included in the matching networks with or without one or more switches.
  • varactor(s) can be included in a matching network to change the capacitance with voltage (i.e., varying the voltage to vary the capacitance).
  • potentiometer(s) can be included in a matching network to change the resistance of the matching network.
  • a matching network can be used to tune an antenna/coil to its transceiver circuit.
  • these matching networks consist of capacitors, inductors, resistors, etc., and are static values.
  • the IMD and external tunable matching networks 205, 233 are designed so that the components can be dynamically and automatically adjusted. The adjustment can be done by implementing a bank of components and switching them in and out with switches, and/or adjusting adjustable components.
  • the external device 104 can be designed to constantly and/or periodically (e.g., based on time intervals, number of packets received from the IMD 150, every packet received from the IMD 150, result of a test of external and/or IMD RSSI, result of measuring the reflection coefficient, result of determining phase difference between the transmit and receive signals) adjust/sweep the antenna matching components of the external and/or IMD tunable matching networks 233, 205 to stay at maximum signal point (e.g., power, voltage current).
  • maximum signal point e.g., power, voltage current
  • the external device 104 may direct the external matching network configuration module 968 to adjust/sweep the external antenna matching components to stay at maximum signal point, and/or the external device 104 may direct the IMD matching network configuration module 271 to adjust/sweep the IMD antenna matching components to stay at maximum signal point.
  • the adjustments of the IMD and external tunable matching networks 205, 233 can be accomplished iteratively, serially, substantially simultaneously, continuously, etc.
  • the external and IMD matching network configuration modules 292, 271 can be directed in a similar 15694WOO1 (013-0615PCT1) 96 PATENT manner to adjust/sweep the external and/or IMD antenna matching components to minimize the reflection coefficient at the target frequency (e.g., 13.56 MHz).
  • Figure 10A illustrates an example of the IMD tunable matching network 205a and the external tunable matching network 233a having a simple pi- match network topology in accordance with embodiments herein.
  • the external tunable matching network 233a is interconnected with the inductive external coil 231 and the external transceiver 235 of the external device 104, and the IMD tunable matching network 205a is interconnected with the inductive IMD coil 202 and the integrated circuit 204 and/or IMD transceiver 208. It should be understood that other components than shown may be included in the external tunable matching network 233a and the IMD tunable matching network 205a. [00378]
  • the external tunable matching network 233a matches the output impedance of the external device 104 (e.g., power amplifier in, of, and/or associated with the external transceiver 235) to the impedance of the inductive external coil 231.
  • the external tunable matching network 233a includes capacitors (C1-C8), inductor L1, and switches (S1-S6).
  • the IMD tunable matching network 205a is also a pi-match network topology which matches the output impedance of the IMD 150 to the inductive IMD coil 202.
  • the IMD tunable matching network 205a includes capacitors (C10-C17), inductor L2, and switches (S10- S16). While the switches S1-S6 and S10-S15 are shown in the open position, each network configuration can have different numbers of open or closed switches. It should be noted that there is no requirement for the external and IMD tunable matching networks 233, 205 to be the same topology.
  • the example pi-match network is shown having inductor(s) in the middle and capacitors on the side, a different pi-match network could be used that has capacitor(s) in the middle with inductors on the side. Further, resistor(s) can be included in parallel or in series with other components.
  • the implementation of the matching network can vary, new and unique embodiments as discussed herein include the use of switches and/or adjustable 15694WOO1 (013-0615PCT1) 97 PATENT components to allow different configurations of the matching networks 205, 233, advantageously allowing the matching networks 205, 233 to be modified dynamically to optimally tune the antenna(s) to changes in the environment. This provides a technological improvement to the field of medical communication that utilizes NFC.
  • the external device 104 and IMD 150 can be programmed, such as based on calculations, to identify which switch(s) to change to increase or decrease frequency of the associated antenna and by how much. This provides the advantage of decreasing the time required to evaluate different matching network configurations of the matching networks 205, 233. [00381] In other embodiments, successive approximation could be used. Again, the external device 104 and IMD 150 can be programmed, such as based on calculations, to identify which switch(s)/adjustable components provide the biggest impact. If a matching network configuration is evaluated that has gone too far or made too big of a change, other switches/adjustable components associated with smaller changes can be open/closed until the matching is optimized.
  • Figure 10B illustrates an example wherein the external tunable matching network 233b of the external device 104 is an L-match topology in accordance with embodiments herein.
  • the external tunable matching 15694WOO1 (013-0615PCT1) 98 PATENT network 233b includes capacitor C20, C21, inductor L20, and switch S20, although more components are contemplated.
  • Figure 10C illustrates an example wherein the external tunable matching network 233c of the external device 104 is a T-match topology in accordance with embodiments herein.
  • the external tunable matching network 233c includes capacitors C30, C31, inductors L30, L31, and switch S30.
  • the IMD 150 can also include an IMD tunable matching network 205 that is the same as or different from the external tunable matching network 233b, 233c. It is not required for the IMD and external tunable matching networks 205, 233 to be the same.
  • Figure 10D illustrates an example of the IMD tunable matching network 205d and the external tunable matching network 233d having a back-to- back L-match network topology in accordance with embodiments herein.
  • the external tunable matching network 233d is interconnected with the external coil 231 and the external transceiver 235 of the external device 104
  • the IMD tunable matching network 205d is interconnected with the inductive IMD coil 202 and the integrated circuit 204 and/or IMD transceiver 208.
  • the external tunable matching network 233b includes capacitors C40, C41, C42, C43, inductors L40, L41, L42, L43, and switches S41, S42, S43, S44, although more components are contemplated.
  • the IMD tunable matching network 205d includes capacitors C50, C51, C52, C53, inductors L51, L52, L53, L54, and switches S50, S51, S52, S53.
  • switches S41, S43, S51, 15694WOO1 (013-0615PCT1) 99 PATENT and S54 are arranged to include or exclude serial component(s), such as an inductor, in the matching network configuration.
  • FIG. 11 illustrates an example process flow 1100 for setting an output power of the external device 104 (e.g., reader) for acquiring IMD data measurements, sensed and/or determined by the IMD 150, in accordance with embodiments herein.
  • the acquired data can be pressure readings and the IMD 150 can be a pressure sensor.
  • the operations of Figure 11 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system.
  • the operations of Figure 11 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 11 are described in a somewhat serial manner, one or more of the operations may be continuous, performed in a different order, and/or performed in parallel with one another.
  • the external device 104 is positioned near or in contact with the patient and also near the implanted location of the IMD 150.
  • the patient may be instructed by a clinician where along their torso to position the external device 104.
  • the external device 104 may be a pillow, blanket, belt, or included within another garment, be comprised of more than one piece wherein the coil or antenna is held within a portion close to the patient and interconnected with a computer, 15694WOO1 (013-0615PCT1) 100 PATENT phone, base station, and/or other external device.
  • the inductive external coil 231 and/or external tunable matching network 233 can be conformable to the shape of the patient.
  • the patient may select an option, such as through a graphical user interface (GUI), to direct the external device 104 to take the reading, such as the pressure reading.
  • GUI graphical user interface
  • the external device 104 can respond, for example, to a selection via a keyboard or GUI, a voice command, a command received via an external device such as an application on a patient’s phone, a command received via the internet such as from a clinician, and/or responsive to a preset time.
  • the patient may have more than one IMD 150, 152 that can be powered and sensed with the external device 104 positioned in one place.
  • the patient may be instructed to move the external device 104 to one or more other location proximate their body to read other IMDs.
  • the below process flow is written from the perspective of a single IMD 150; however, if more than one IMD is powered by the external device 104 (e.g., IMD 152 of Figure 1A), each powered IMD 150, 152, for example, will collect pressure data (or other data) and transmit the data to the external device 104.
  • the external device 104 can simultaneously communicate with another IMD that has its own battery source.
  • the other IMD can receive NFC communications from the external device 104 and/or wake up as a result of detecting the external NFC signals, and send IMD NFC signals, such as packets, to the external device 104 at the same time the external device 104 is receiving IMD NFC signals from the IMD 150.
  • one or more processors or circuits set an output power of the external device 104 at an initial level.
  • the initial level may be preset, such as by the manufacturer or clinician, at 100 mW, 200 mW, etc. In other embodiments, the initial level can be based on a previous level, such as based on one or more prior sessions.
  • the one or more processors or circuits may set the initial level of the output power of the external device 104 at 3.5 W, or slightly less than the lowest output power level. This provides the advantage of quicker connectivity by learning the power requirements of the particular system, wherein variabilities exist between patients based on positioning of the external device 104, depth of the IMD 150, etc. When connectivity is quickly achieved, the length of the collection session can be minimized, thus improving patient compliance.
  • the one or more processors or circuits direct the external device 104 to transmit external NFC signals to energize the IMD 150.
  • the one or more processors or circuits determine whether the external device 104 received a response from the IMD 150. In some embodiment, the one or more processors of the external device 104 measure how much power is received back from the IMD 150 to determine the external RSSI. In some embodiments, the external device 104 may wait a predetermined time for a response. In some embodiments, the one or more processors or circuits of the IMD 150 determine the IMD RSSI, which is an indication of how much power the IMD 150 received, and transmit the IMD RSSI to the external device 104.
  • a power threshold can be a maximum output power level based on regulatory requirements, anatomical depth of the IMD 150, etc., and prevents over-voltage conditions and over-heating of the IMD 150.
  • the power threshold can be set at 7 W, 8 W, 9 W, 10 W, and the like.
  • a message indicating a power level can be logged/displayed.
  • a 15694WOO1 (013-0615PCT1) 102 PATENT message can be logged and/or transmitted to the clinician, indicating a positioning error, an output power too high error, and/or the potential non-responsiveness of the IMD 150.
  • the one or more processors or circuits can increase the output power level, such as in 100-250 mW increments.
  • the output power level can be increased by increasing a gain amplifier on a power amplifier of the external transceiver 235 or by increasing the input power to the power amplifier.
  • the one or more processors or circuits direct the external device 104 to transmit external NFC signals at the increased output power level to energize the IMD 150.
  • the method flows to 1108 and again monitors for a response from the IMD 150.
  • the external device 104 When the external device 104 receives a response from the IMD 150, process flows to 1116. In some cases, the output power can be increased to ensure enough margin. Until evaluated again, such as in Figure 18 discussed further below, the current output power level is used to transmit external NFC signals to the IMD 150. [00400] In some embodiments, the external device 104 can display a power level and/or coupling quality output to the patient. This can have the advantageous effect of providing feedback to the patient regarding placement of the inductive external coil 231, effect of patient movement on the reading, and the like. A visual indicator, such as a battery indictor with horizonal or vertical lines indicating the degree of optimization accomplished at the current placement, and/or auditory cues could be provided to the patient to prompt patient behavior.
  • a visual indicator such as a battery indictor with horizonal or vertical lines indicating the degree of optimization accomplished at the current placement, and/or auditory cues could be provided to the patient to prompt patient behavior.
  • the IMD 150 can transmit packets of information via NFC telemetry 252.
  • One or more packets can include information associated with the IMD 150, such as pressure measurements (e.g., a capacitance converted to a digital word), a UID 242, calibration information 244, baseline 15694WOO1 (013-0615PCT1) 103 PATENT information 258, as well as any other identification information such as a patient ID.
  • the packet of data or payload can be encoded, including an error bit and encrypted.
  • a plurality of packets can be transmitted in a burst.
  • the one or more processors or circuits of the external device 104 receive the packet(s).
  • the packet(s) can be stored in a memory 970 on the external device 104 until manually deleted, for a predetermined period of time, until transmitted to an external health system, and the like.
  • the external device 104 continues to power the IMD 150 and collect data until a collection session is complete. For example, a typical reading or collection session can be 18 seconds of data captured at 100 Hz (or 250 Hz). Other lengths of time and frequency are contemplated.
  • a typical reading or collection session can be 18 seconds of data captured at 100 Hz (or 250 Hz). Other lengths of time and frequency are contemplated.
  • the process flows simultaneously to one or more of Figures 12-18, and the one or more processors or circuits one or more of i) identify the external matching network configuration that provides the best reflection coefficient to tune the inductive external coil 231 to its external transceiver 235, ii) identify the external matching network configuration that provides the highest RSSI to tune the inductive external coil 231 to its external transceiver 235, iii) identify the external matching network configuration that provides the least phase difference, iv) monitor the output power, and v) monitor the RSSI. Simultaneously, the one or more processors continue to receive packets from the IMD 150 that can include IMD data measurements, calibration information, IMD identification information, etc.
  • the system dynamically, e.g., in real-time, receives IMD NFC signals from the inductive IMD coil 202 that contain data measurements, and the external device 104 determines at least one characteristic of interest (COI) from the IMD NFC signals that contain the data measurements.
  • COI characteristic of interest
  • the one or more processors or circuits determine if the data collection session is complete. If more IMD data is to be collected, the process returns to 1118.
  • the process of determining the capacitance of the MEMS capacitive element 206, converting it to a digital word, and transmitting the data over NFC to the external device 104 occurs thousands of times during the typical reading.
  • the capacitance value can be sampled at a specified sampling frequency without a break in time until the time duration (e.g., 18 seconds) is reached.
  • the process flows to 1122, and the one or more processors or circuits stop transmitting external NFC signals and transmit the pressure data and/or other data received from the external device 104 to a healthcare system, such as to an electronic location accessible by a clinician associated with the patient.
  • the patient may take one reading (e.g., one collection session) a day.
  • the pressure data can be correlated with a time the patient takes a medication. The patient may be prompted, such as through the external device 104, to take measurements at particular times relative to ingestion to determine the efficacy of the medication and/or the dose.
  • Figure 12 describes a process for dynamically tuning the inductive external coil 231 to minimize the reflection coefficient
  • Figure 13 describes a process for dynamically tuning the inductive external coil 231 based on RSSI
  • Figure 14 describes a process for dynamically tuning the inductive external coil 231 based on phase difference.
  • the system can be designed to use one of the 15694WOO1 (013-0615PCT1) 105 PATENT processes, to use all of the processes at different times (e.g., serially) or to conduct all of the processes simultaneously.
  • dynamically tuning the inductive external coil 231 can be accomplished in real-time, such as during a beginning, middle, or end of a data exchange session, which includes an interval of time during which the IMD 150 sends data measurements to the external device 104.
  • the IMD 150 is a pulmonary artery pressure (PAP) sensor
  • the external device 104 can dynamically tune the inductive external coil 231 at any time while simultaneously receiving data measurements, such as PAP measurements, from the PAP sensor.
  • PAP pulmonary artery pressure
  • the process for dynamically tuning the inductive external coil 231 can occur before the IMD 150 conducts measurements and transmits IMD data measurements to the external device 104, and/or the measurement and transmission of IMD data measurements can be suspended while the dynamic tuning of the inductive external coil 231 is accomplished.
  • Figure 12 illustrates an example process flow 1200 for dynamically receiving IMD data measurements and tuning the inductive external coil 231 to minimize the reflection coefficient in accordance with embodiments herein.
  • the IMD data measurements can be pressure readings and the IMD 150 can be a pressure sensor.
  • the dynamic tuning of the inductive external coil 231, by sweeping the components of the external tunable matching network 233 can be accomplished in less than one second.
  • the operations of Figure 12 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system.
  • the operations of Figure 12 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system.
  • one or more of the operations may be 15694WOO1 (013-0615PCT1) 106 PATENT continuous, performed in a different order, and/or performed in parallel with one another.
  • one or more processors or circuits configure a first external matching network configuration.
  • the external device 104 can configure the external tunable matching network 233 of the inductive external coil 231 to a first external matching network configuration.
  • the external matching network configuration module 968 ( Figure 9C) can command particular switches S1-S6 of the external tunable matching network 233a ( Figure 10A) open or closed and/or set values/parameters for adjustable components.
  • the first impedance can be achieved by, for example, opening all switches or closing all switches.
  • a course sweep of the matching components could be implemented, wherein not all of the possible configurations are evaluated, or a fine sweep could be used, wherein all of the possible configurations are evaluated.
  • a course or fine sweep of the possible external matching network configurations can be determined within a certain range (e.g., around the configuration previously determined to result in the minimum reflection coefficient).
  • the one or more processors or circuits of the IMD 150 receive the external NFC signals and at 1208, the one or more processors or circuits transmit IMD NFC signals that can include IMD data measurements.
  • the one or more processors or circuits of the external device 104 receive the IMD NFC signals.
  • the one or more processors or circuits determine a characteristic of interest (COI) associated with the IMD NFC signals and the first external matching network configuration.
  • COI characteristic of interest
  • the COI is a voltage level and can be used to determine the reflection coefficient. In other embodiments, the COI can be an amplitude.
  • the one or more processors or circuits determine a COI of and/or associated with the transmitted external NFC signals and the first external matching network configuration.
  • the COI can be a voltage level.
  • the one or more processors or circuits, such as of the external device 104 calculate the reflection coefficient associated with the first external matching network configuration as the ratio of the reflected wave (e.g., IMD NFC signals) to the incident wave (e.g., external NFC signals.)
  • the reflection coefficient and the associated external matching network configuration can be saved, at least temporarily, in the memory 970.
  • the one or more processors or circuits determine whether another external matching network configuration should be evaluated to determine the associated reflection coefficient. [00418] If another configuration is to be evaluated, at 1220, the one or more processors or circuits change at least one parameter of the inductive external coil 231 by configuring the second external matching network configuration, and the process returns to 1204.
  • a parameter may be the position of a switch, a setting of an adjustable component, or a voltage input level, but is not so limited.
  • 1204-1218 are repeated for the second external matching network configuration, transmitting second (successive) external NFC signals, receiving second (successive) IMD NFC signals, determining a second COI of and/or associated with the second IMD NFC signals and the second external matching network configuration, and determining the associated reflection coefficient.
  • the process is repeated for any successive configuration of the external tunable matching network 233.
  • the external matching network configuration module 968 can direct first switch S1 to open, and then the reflection coefficient is determined.
  • the external matching network configuration module 968 can successively direct each of the switches S2-S6 to open, and then the associated, 15694WOO1 (013-0615PCT1) 108 PATENT successive reflection coefficient is determined. In some embodiments, not all of the switches may be opened or closed during the evaluation process. [00421] Once the associated reflection coefficients have been determined for the external matching network configurations to be evaluated, process flows to 1222 and the one or more processors or circuits identify the external matching network configuration having the minimum reflection coefficient. The identified external matching network configuration is used to transmit the external NFC signals until a trigger is received, a time interval is satisfied, etc., indicating that the reflection coefficient should be evaluated.
  • the one or more processors or circuits can iteratively evaluate the change between successive reflection coefficient values. For example, the external matching network configurations may be cycled through and evaluated for improvement. When the reflection coefficient value does not improve (e.g., lower), the one or more processors or circuits may select the previous external matching network configuration.
  • the IMD tunable matching network 205 can be configured. For example, in Figure 12, based on a command from the external device 104 or a command from within the IMD 150 (e.g., a trigger, an automatic setting, interval of time), the IMD 150 can change at least one parameter of the inductive IMD coil 202 by configuring the IMD matching network configuration.
  • the IMD 150 can transmit, via a packet, information regarding the instant IMD matching network configuration, which the external device 104 can correlate with the measured power reflected back from the inductive IMD coil 202, and determine the associated reflection coefficient.
  • the external device 104 can receive IMD data associated with at least two of the IMD matching network configurations and can respond to the IMD 150 with a command/instruction indicating what IMD matching network configuration to use. 15694WOO1 (013-0615PCT1) 109 PATENT [00424]
  • the external device 104 can also verify that the output frequency of the inductive external coil 231 is within a predetermined range of 13.56 MHz.
  • process of Figure 12 can be used to dynamically receive IMD data measurements while tuning the IMD tunable matching network 205 of the inductive IMD coil 202 to minimize the reflection coefficient. Multiple configurations of the IMD tunable matching network 205 can be evaluated to identify the IMD matching network configuration with the minimum reflection coefficient. In some cases, the evaluation of the IMD tunable matching network 205 can alternate with the evaluation of the external tunable matching network 233, occur simultaneously, interactively, etc.
  • Figure 13 illustrates an example process flow 1300 for dynamically receiving IMD data measurements and tuning the inductive external coil 231 based on IMD RSSI and external device RSSI in accordance with embodiments herein.
  • the IMD data measurements can be pressure readings and the IMD 150 can be a pressure sensor, and the RSSI can be measured in decibels (dB) of power.
  • the operations of Figure 13 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system.
  • the operations of Figure 13 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 13 are described in a somewhat serial manner, one or more of the operations may be continuous, performed in a different order, and/or performed in parallel with one another.
  • the external matching network configuration module 968 ( Figure 9C) can command particular switches S1-S6 of the external tunable matching network 233a ( Figure 10A) open or closed, set values/parameters for adjustable components, perform course and/or fine sweeps, evaluate some of all configurations, etc.
  • the RSSI values and associated external matching network configuration and/or IMD matching network configuration can be stored in the memory 970 at least temporarily.
  • one or more processors or circuits configure a first external matching network configuration.
  • the external device 104 can configure the external tunable matching network 233 of the inductive external coil 231 to a first external matching network configuration.
  • the one or more processors or circuits transmit external NFC signals using the first external matching network configuration and request the IMD RSSI, such as by sending a request packet.
  • the one or more processors or circuits of the IMD 150 receive the request, and at 1308, the one or more processors or circuits determine the IMD RSSI, which is an indication of how much power the IMD 150 received.
  • the COI in this example is the IMD RSSI that is of and/or associated with the first external matching network configuration.
  • the one or more processors or circuits transmit IMD NFC signals that include the IMD RSSI and IMD data measurements, such as in one or more data packet.
  • the IMD matching network configuration associated with the IMD RSSI may also be sent. 15694WOO1 (013-0615PCT1) 111 PATENT [00433]
  • the one or more processors or circuits of the external device 104 receive the IMD NFC signals and the IMD RSSI.
  • the one or more processors or circuits determine an external RSSI (e.g., COI) of and/or associated with the first external matching network configuration (and optionally, the IMD matching network configuration). For example, the one or more processors or circuits of the external device 104 measure how much power is received back from the IMD 150.
  • COI external RSSI
  • the one or more processors or circuits determine whether another external matching network configuration should be evaluated. [00436] If another configuration is to be evaluated, at 1318 the one or more processors or circuits change at least one parameter of the inductive external coil 231 by configuring the next external matching network configuration, and the process returns to 1304.
  • the external matching network configuration module 968 can close or open one or more of switches S1-S6, change the value or setting of an adjustable component, or change the voltage input level.
  • [00437] 1304-1316 are repeated for the second external matching network configuration, transmitting second (successive) external NFC signals, determining a second IMD RSSI (e.g., COI), receiving second (successive) IMD NFC signals including the IMD RSSI (e.g., COI), and determining a second external RSSI (e.g., COI) of and/or associated with the second IMD NFC signals and the second external matching network configuration.
  • the process is repeated for any successive configuration of the external tunable matching network 233.
  • the one or more processors can identify the external matching network configuration to maximize one of the IMD RSSI or external RSSI, or to maximize both of the IMD 15694WOO1 (013-0615PCT1) 112 PATENT RSSI and external RSSI.
  • the identified external matching network configuration is used to transmit the external NFC signals until a trigger is received, a time interval is satisfied, etc., indicating that the RSSIs should be evaluated.
  • the external matching network configuration can be selected based on i) both the highest IMD RSSI and external RSSI, ii) the highest IMD RSSI, or iii) the highest external RSSI.
  • the process of Figure 13 can be used to dynamically receive IMD data measurements while tuning the inductive IMD coil 202 based on IMD RSSI and external device RSSI.
  • Multiple configurations of the IMD tunable matching network 205 can be evaluated to identify the IMD matching network configuration with i) both the highest IMD RSSI and external RSSI, ii) the highest IMD RSSI, or iii) the highest external RSSI.
  • FIG 14 illustrates an example process flow 1400 for dynamically receiving IMD data measurements and tuning the inductive external coil 231 to optimize the phase difference in accordance with embodiments herein.
  • the IMD data measurements can be pressure readings and the IMD 150 can be an implantable pressure sensor.
  • the dynamic tuning of the inductive external coil 231, by sweeping the components of the external tunable matching network 233 can be accomplished in less than one second.
  • the operations of Figure 14 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system.
  • the operations of Figure 14 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 14 are described in a somewhat serial manner, one or more of the operations may be 15694WOO1 (013-0615PCT1) 113 PATENT continuous, performed in a different order, and/or performed in parallel with one another.
  • one or more processors or circuits configure a first external matching network configuration.
  • the external device 104 can configure the external tunable matching network 233 of the inductive external coil 231 to a first external matching network configuration.
  • the external matching network configuration module 968 ( Figure 9C) can command particular switches S1-S6 of the external tunable matching network 233a ( Figure 10A) open or closed and/or set values/parameters for adjustable components.
  • the first impedance can be achieved by, for example, opening all switches or closing all switches.
  • a course sweep of the matching components could be implemented, wherein not all of the possible configurations are evaluated, or a fine sweep could be used, wherein all of the possible configurations are evaluated.
  • a course or fine sweep of the possible external matching network configurations can be determined within a certain range (e.g., around the configuration previously determined to result in the minimum phase difference).
  • the one or more processors or circuits transmit external NFC signals using the first external matching network configuration.
  • the one or more processors or circuits of the IMD 150 receive the external NFC signals and at 1408, the one or more processors or circuits transmit IMD NFC signals that can include IMD data measurements.
  • the one or more processors or circuits of the external device 104 receive the IMD NFC signals.
  • the one or more processors or circuits determine the phase difference associated with the first external matching network configuration as the difference between the received IMD NFC signals and the transmitted external NFC signals.
  • the phase difference and the associated external matching network configuration can be saved, at least 15694WOO1 (013-0615PCT1) 114 PATENT temporarily, in the memory 970.
  • the phase difference is a COI based on the IMD NFC signals.
  • the phase difference is also a COI based on the external NFC signals.
  • the one or more processors or circuits determine whether another external matching network configuration should be evaluated to determine the associated phase difference.
  • the one or more processors or circuits change at least one parameter of the inductive external coil 231 by configuring the second external matching network configuration, and the process returns to 1404.
  • a parameter may be the position of a switch, a setting of an adjustable component, or a voltage input level, but is not so limited.
  • 1404-1414 are repeated for the second external matching network configuration, transmitting second (successive) external NFC signals, receiving second (successive) IMD NFC signals, determining a second COI (e.g., the associated phase difference) associated with the second IMD NFC signals, the second external NFC signals, and the second external matching network configuration.
  • a second COI e.g., the associated phase difference
  • the process is repeated for any successive configuration of the external tunable matching network 233.
  • the external matching network configuration module 968 can direct first switch S1 to open, change an adjustable component value, vary an input voltage, etc., and then the phase difference is determined.
  • the external matching network configuration module 968 can successively configure to external tunable matching network 233, and then the associated, successive phase difference is determined. In some embodiments, not all of the configurations may be evaluated.
  • the identified external 15694WOO1 (013-0615PCT1) 115 PATENT matching network configuration is used to transmit the external NFC signals until a trigger is received, a time interval is satisfied, etc., indicating that the phase difference should be evaluated.
  • the one or more processors or circuits can iteratively evaluate the change between successive phase differences. For example, the external matching network configurations may be cycled through and evaluated for improvement. When the phase difference does not improve, the one or more processors may select the previous external matching network configuration.
  • the IMD tunable matching network 205 can be configured.
  • the IMD 150 can change at least one parameter of the IMD coil 202 by configuring the IMD matching network configuration.
  • the IMD 150 can transmit, via a packet, information regarding the instant IMD matching network configuration, which the external device 104 can correlate with the associated phase difference.
  • the external device 104 can receive IMD data associated with at least two of the IMD matching network configurations and can respond to the IMD 150 with a command/instruction indicating what IMD matching network configuration to use.
  • the IMD 150 can determine the phase difference between the external NFC signals (received at the IMD 150) and the IMD NFC signals (transmitted by the IMD 150).
  • the IMD 150 can configure the IMD matching network configurations and determine the associated phase differences until the optimal phase difference is determined.
  • the process of Figure 14 can be used to dynamically receive IMD data measurements while tuning the inductive IMD coil 202 to optimize the phase difference.
  • Multiple configurations of the IMD tunable matching network 205 can be evaluated to identify the IMD matching network 15694WOO1 (013-0615PCT1) 116 PATENT configuration with the optimal phase difference.
  • Figures 15-18 illustrate several process flows that can be used to determine when to tune the external tunable matching network 233 and/or the IMD tunable matching network 205 while the external device 104 is dynamically receiving IMD data measurements. While each of the methods are initiated based on a time interval being satisfied, it should be understood that other factors can initiate the method, such as the number of packets received, a temperature indication from the IMD 150 that is within a predetermined range, bad, lost or missed data packets, etc.
  • a time interval has an associated predetermined duration of time between starting and ending points, and the satisfaction of the time interval indicates that the predetermined duration of time has passed since the starting point.
  • the various process flows can run concurrently, serially, simultaneously, etc.
  • the process flows of Figures 15-18 discuss tuning (e.g., dynamically tuning) the external tunable matching network 233 of the external device 104, if should be understood that time interval(s) can equally be applied to determine when/if to tune the IMD tunable matching network 205 of the IMD 150.
  • Figure 15 illustrates an example process flow 1500 for tuning the inductive external coil 231 based on a time interval in accordance with embodiments herein.
  • the time interval (e.g., time interval 1) can be reset.
  • the operations of Figure 15 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system.
  • the operations of Figure 15 may be partially 15694WOO1 (013-0615PCT1) 117 PATENT implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system.
  • the operations of Figure 15 are described in a somewhat serial manner, one or more of the operations may be continuous, performed in a different order, and/or performed in parallel with one another.
  • the NFC communication between the external device 104 and the IMD 150 is established, and the external device is receiving the IMD data measurements transmitted by the IMD 150, as discussed in 1116 of Figure 11.
  • the one or more processors or circuits determine if a time interval (e.g., time interval 1) is satisfied.
  • the time interval 1 can be programmed by the physician or the manufacturer.
  • the time interval may be programmed to have a predetermined duration of time of a few seconds or longer between starting and ending points.
  • Additional or other time intervals can be programmed to have different predetermined durations of time between their starting and ending points.
  • the external tunable matching network 233 and/or IMD tunable matching network 205 has been configured, flow passes to 1508 and the one or more processors or circuits reset the time interval 1, and flow returns to 1504.
  • the inductive IMD coil 202 can be tuned simultaneously and/or serially with respect to the inductive external coil 231.
  • process flows may utilize offset time interval 1, such that the external coil 231 is tuned, followed by tuning the IMD coil 202, and so on.
  • Figure 16 illustrates an example process flow 1600 for tuning the external coil 231 based on phase difference between the transmit and receive 15694WOO1 (013-0615PCT1) 118 PATENT signals in accordance with embodiments herein. For example, every time the inductive external coil 231 is tuned, the time interval (e.g., time interval 2) can be reset. This has the advantage of tuning the inductive external coil 231 to ensure that the communication parameters remain optimized.
  • the operations of Figure 16 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system.
  • the operations of Figure 16 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 16 are described in a somewhat serial manner, one or more of the operations may be continuous, performed in a different order, and/or performed in parallel with one another.
  • the NFC communication between the external device 104 and the IMD 150 is established and the external device is receiving the IMD data measurements transmitted by the IMD 150, as discussed in 1116 of Figure 11.
  • the one or more processors or circuits determine if a time interval (e.g., time interval 2) is satisfied.
  • the time interval 2 can be programmed by the physician or the manufacturer and can be shorter or less than time interval 1.
  • the one or more processors or circuits can monitor for a predetermined number of packets to be transmit and/or received, then initiate measuring the phase difference between the transmit and receive signals.
  • phase difference threshold can be a range, percentage, and/or number indicating an upper limit for phase differences between the signals.
  • phase difference threshold is not satisfied, i.e., the phase difference is within an acceptable range
  • the phase difference is satisfied at 1608 flow passes to 1610 and the one or more processors or circuits accomplish the tuning of the inductive external coil 231 and/or inductive IMD coil 202 in accordance with Figure 12, Figure 13, and/or Figure 14.
  • the sweep of the components of the external tunable matching network 233 and/or IMD tunable matching network 205 may be over a smaller range, and the sweep may evaluate a greater number of configurations within the smaller range compared to a broader “ball park” range.
  • the one or more processors or circuits can determine if a time interval (e.g., time interval 2 or other time interval less than time interval 1) is satisfied.
  • the one or more processors or circuits can determine the associated reflection coefficient (e.g., COI). If the reflection coefficient satisfies a reflection coefficient 15694WOO1 (013-0615PCT1) 120 PATENT threshold, the one or more processors or circuits can accomplish the tuning of the external coil 231 and/or IMD coil 202 in accordance with Figure 12, Figure 13, and/or Figure 14.
  • Figure 17 illustrates an example process flow 1700 for tuning the inductive external coil 231 based on the IMD RSSI and/or the external RSSI in accordance with embodiments herein.
  • the operations of Figure 17 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system.
  • the operations of Figure 17 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 17 are described in a somewhat serial manner, one or more of the operations may be continuous, performed in a different order, and/or performed in parallel with one another.
  • the NFC communication between the external device 104 and the IMD 150 is established and the external device is receiving the IMD data measurements transmitted by the IMD 150, as discussed in 1116 of Figure 11.
  • the one or more processors or circuits determine if a time interval (e.g., time interval 3) is satisfied.
  • the time interval 3 can be programmed by the physician or the manufacturer and can be less than time interval 1 of Figure 15.
  • the one or more processors or circuits can monitor for a predetermined number of packets to be transmit and/or received, then initiate the determination of the IMD RSSI and the external RSSI.
  • the one or more processors request the IMD RSSI and determine the external RSSI, as discussed previously in Figure 13. 15694WOO1 (013-0615PCT1) 121 PATENT [00475]
  • the one or more processors or circuits determine if the IMD RSSI and/or the external RSSI satisfy one or more RSSI threshold (e.g., percentage, range, predetermined value, programmed value, value based on IMD RSSI when communication was established, value based on external RSSI when communication was established). As discussed above, it is important to maximize power transfer.
  • the RSSI threshold may be satisfied. If the RSSI threshold is not satisfied, i.e., the IMD RSSI and/or external RSSI are within an acceptable range, flow passes to 1712 and the one or more processors or circuits reset the time interval 3.
  • the RSSI threshold may be a value, such as mW, based on the initial output power or a predetermined or programmed value. For example, if the IMD RSSI was 5 mW when communication between the IMD 150 and external device 104 was established, the RSSI threshold may be set at 2 mW, based on the initial output power.
  • the RSSI threshold may be associated with the external RSSI, the IMD RSSI, both, and/or that each of the external RSSI and IMD RSSI can have an associated RSSI threshold.
  • the RSSI threshold is satisfied at 1708, flow passes to 1710 and the one or more processors or circuits accomplish the tuning of the inductive external coil 231 and/or IMD coil 202 in accordance with Figure 12, Figure 13, and/or Figure 14.
  • the external tunable matching network 233 has been configured, flow passes to 1712 and the one or more processors or circuits reset the time interval 3, and flow returns to 1704.
  • Figure 18 illustrates an example process flow 1800 for tuning the inductive external coil 231 based on output power of the external device 104 in accordance with embodiments herein.
  • the operations of Figure 18 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system.
  • the operations of Figure 18 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 18 are described in a somewhat serial manner, one or more of the operations may be continuous, performed in a different order, and/or performed in parallel with one another.
  • the NFC communication between the external device 104 and the IMD 150 is established and the external device is receiving the IMD data measurements transmitted by the IMD 150, as discussed in 1116 of Figure 11.
  • the one or more processors or circuits determine if a time interval (e.g., time interval 4) is satisfied.
  • the time interval 4 can be programmed by the physician or the manufacturer and can be less than time interval 1 of Figure 15.
  • the one or more processors or circuits can monitor for a predetermined number of packets to be transmit and/or received, then initiate the determination of the output power. [00482] If the time interval 4 is satisfied at 1804 (the predetermined duration of time of the time interval 4 has passed), process flows to 1806 and the one or more processors or circuits determine the output power of the external device 104. [00483] At 1808, the one or more processors or circuits determine if the output power satisfies an output power threshold.
  • the output power determined at 1808 can be compared to the output power set during the process of Figure 11, to a predetermined maximum (e.g., 7.5 W, 8 W, 8.5 W). If the output power threshold is not satisfied, i.e., the output power is within an acceptable 15694WOO1 (013-0615PCT1) 123 PATENT range, flow passes to 1814 and the one or more processors or circuits reset the time interval 4. [00484] If the output power threshold is satisfied at 1808, flow passes to 1810 and the one or more processors or circuits decrease the output power, such as to a second power threshold.
  • a predetermined maximum e.g., 7.5 W, 8 W, 8.5 W.
  • the output power can be decreased to a predetermined value, and/or set to the output power level set at 1108 in Figure 11 when communication was established.
  • the one or more processors or circuits accomplish the tuning of the inductive external coil 231 and/or inductive IMD coil 202 in accordance with Figure 12, Figure 13, and/or Figure 14.
  • aspects may take the form of an entirely hardware embodiment or an 15694WOO1 (013-0615PCT1) 124 PATENT embodiment including hardware and software that may all generally be referred to herein as a “circuit,” “module” or “system.”
  • aspects may take the form of a computer (device) program product embodied in one or more computer (device) readable storage medium(s) having computer (device) readable program code embodied thereon.
  • Any combination of one or more non-signal computer (device) readable media may be utilized.
  • the non-signal media may be a storage medium.
  • a storage medium may be, for example, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a storage medium would include the following: a portable computer diskette, a hard disk, a random access memory (RAM), a dynamic random access memory (DRAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.
  • Program code for carrying out operations may be written in any combination of one or more programming languages.
  • the program code may execute entirely on a single device, partly on a single device, as a stand-alone software package, partly on single device and partly on another device, or entirely on the other device.
  • the devices may be connected through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made through other devices (for example, through the Internet using an Internet Service Provider) or through a hard wire connection, such as over a USB connection.
  • LAN local area network
  • WAN wide area network
  • a server having a first processor, a network interface, and a storage device for storing code may store the program code for carrying out the operations and provide this code through its network interface via a network to a second device having a second processor for execution of the code on the second device.
  • the program instructions may be provided to a processor of a general-purpose computer, special purpose computer, or other programmable data processing device or information handling device to produce a machine, such that the instructions, which execute via a processor of the device implement the functions/acts specified.
  • the program instructions may also be stored in a device readable medium that can direct a device to function in a particular manner, such that the instructions stored in the device readable medium produce an article of manufacture including instructions which implement the function/act specified.
  • the modules/controllers herein may represent circuit modules that may be implemented as hardware with associated instructions (for example, software stored on a tangible and non-transitory computer readable storage medium, such as a computer hard drive, ROM, RAM, or the like) that perform the operations described herein.
  • a tangible and non-transitory computer readable storage medium such as a computer hard drive, ROM, RAM, or the like
  • the above examples are exemplary only, and are thus not intended to limit in any way the definition and/or meaning of the term “controller.”
  • the units/modules/applications herein may execute a set of instructions that are stored in one or more storage elements, in order to process data.
  • the storage elements may also store data or other information as desired or needed.
  • the storage element may be in the form of an information source or a 15694WOO1 (013-0615PCT1) 126 PATENT physical memory element within the modules/controllers herein.
  • the set of instructions may include various commands that instruct the modules/applications herein to perform specific operations such as the methods and processes of the various embodiments of the subject matter described herein.
  • the set of instructions may be in the form of a software program.
  • the software may be in various forms such as system software or application software. Further, the software may be in the form of a collection of separate programs or modules, a program module within a larger program or a portion of a program module.
  • the software also may include modular programming in the form of object-oriented programming.
  • the processing of input data by the processing machine may be in response to user commands, or in response to results of previous processing, or in response to a request made by another processing machine.

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Abstract

An implantable sensor includes a coil, a capacitive element, and an integrated circuit. The coil is configured to receive near field communication (NFC) signals from an external device and to transmit return NFC signals to the external device. The capacitive element has a capacitance configured to vary in response to changes in pressure. The integrated circuit is coupled to the capacitive element and includes at least one of a processor or circuit configured to generate pressure data based on the capacitance of the capacitive element, encode the pressure data to form encoded pressure data, and modulate the return NFC signal, to be transmitted by the coil, based on the encoded pressure data.

Description

METHOD AND DEVICE FOR CARDIAC PRESSURE SENSING USING AN ACTIVE IMPLANTABLE DEVICE AND NEAR FIELD COMMUNICATION CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to United States Provisional Application No. 63/574,335, titled “Method and Device for Cardiac Pressure Sensing Using an Active Implantable Device and Near Field Communication”, which was filed on 04-April-2024, and to United State Provisional Application No. 63/756,947, titled “Method and Device for Cardiac Pressure Sensing Using an Active Implantable Device and Near Field Communication”, which was filed on 11- February-2025, the complete subject matter of which are expressly incorporated herein by reference in their entirety. TECHNICAL FIELD [0002] Embodiments of the present disclosure generally relate to methods and devices for acquiring cardiac pressure data and transmitting the data to an external device. BACKGROUND [0003] State of the art commercial implantable heart failure pressure sensors currently rely on complex analog radio frequency (RF) acquisition and tracking to interrogate passive sensors implanted deep (e.g., up to six inches) within the body. This method is prone to signal acquisition issues and sensitivity to noise, movement, and the environment in general. As a result, the current systems can be difficult to use and difficult to obtain a measurement that is consistent, reliable, and accurate. Additionally, current passive sensors do not have unique serial numbers, patient information or calibration information stored on the device itself, which requires the management of an external device that has to be 15694WOO1 (013-0615PCT1) 1 PATENT manually kept or paired with the patient. Further, since all the data is analog, none of the data is encrypted or protected. [0004] In addition, the current systems may be difficult for a patient to use at home to obtain measurements that are consistent, reliable, and accurate. In the hemodynamic monitoring system, the patient places the coil or antenna of the external device on or proximate to their body. The implant is powered via an RF signal transmitted by the external device. Bidirectional communication is based on modulating RF signals between the external system and implant. Due to this wireless functionality of communication and powering, antennas are utilized both on the implant and the external system. The antennas inherently face sensitivity due to variability of the human body composition, location, and distance between the interfacing antennas. For example, the human body has dielectric properties that are different than air, and also vary from person to person as well as from day to day within the same person, which ultimately affects antenna/wireless performance. Also, the coil/antenna of the external system is sensitive to antenna form factor (e.g., belt, sash, pillow, blanket) as well as the positioning of the antenna relative to the body. Other environmental factors such as nearby metal can also impact communication quality. Additionally, the proximity of the external and implanted antennas (i.e. implant depth) will affect the antenna tuning as well as the amount of power needed to interface the systems effectively. Due to at least these variabilities, it is undesirable to use a fixed communication configuration to transmit data between the IMD and the external device. [0005] A need remains for methods and devices that can accurately acquire data within the body, while utilizing communication methods to transmit the data to an external device in a safe and secure manner, as well as methods and devices that can accurately address the variability of the environment and improve the communication between the IMD and external device. SUMMARY 15694WOO1 (013-0615PCT1) 2 PATENT [0006] In accordance with embodiments herein, an implantable medical device (IMD) comprises a coil configured to receive near field communication (NFC) signals from an external device and to transmit return NFC signals to the external device. The IMD includes a capacitive element that has a capacitance configured to vary in response to changes in pressure. The IMD also includes an integrated circuit coupled to the capacitive element. The integrated circuit includes at least one of a processor or circuit configured to generate pressure data based on the capacitance of the capacitive element, encode the pressure data to form encoded pressure data, and modulate the return NFC signal, to be transmitted by the coil, based on the encoded pressure data. [0007] Optionally, wherein the at least one of a processor or circuit includes a capacitance to digital (C/D) converter configured to measure the capacitance of the capacitive element and digitally generate the pressure data based on the capacitance of the capacitive element. [0008] Optionally, wherein the at least one of a processor or circuit is further configured to apply serial encoding to the digital pressure data. [0009] Optionally, wherein the at least one of a processor or circuit is further configured to serial encode the digital pressure data by applying serial encoding. [0010] Optionally, wherein the serial encoding is one of: Non-Return-to-Zero (NRZ) encoding, Non-Return-to-Zero-Inverted (NRZI) encoding, Return-to-Zero (RZ) encoding, or Manchester encoding. [0011] Optionally, wherein the C/D converter comprises a relaxation oscillator that includes a current source to charge and discharge the capacitive element, a feedback loop to form an oscillator, and a second oscillator configured to measure a duration of charge and discharge cycles of the capacitive element, the duration indicative of the capacitance of the capacitive element. [0012] Optionally, wherein the C/D converter comprises a relaxation oscillator that includes a current source configured to charge and discharge the capacitive element, a first oscillator formed by a feedback loop, and a second 15694WOO1 (013-0615PCT1) 3 PATENT oscillator configured to measure a duration of charge and discharge cycles of the capacitive element, the duration indicative of the capacitance of the capacitive element. [0013] Optionally, wherein the at least one of a processor or circuit is further configured to modulate the return NFC signal utilizing load modulation to transition an impedance of the coil between first and second states corresponding to data values in the encoded pressure data. [0014] Optionally, wherein the transition of the impedance from the first state to the second state corresponds to a logical one in the encoded pressure data and the transition of the impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data. [0015] Optionally, wherein the at least one of a processor or circuit is further configured to apply encryption to the encoded pressure data to form encrypted pressure data, the return NFC signal modulated based on the encrypted pressure data. [0016] Optionally, wherein the at least one of a processor or circuit is further configured to encrypt the encoded pressure data to form encrypted pressure data, the return NFC signal modulated based on the encrypted pressure data. [0017] Optionally, wherein the coil has a length selected within an interval of from 2mm to 20mm, a width selected within an interval of from 1mm to 4mm, and a height selected within an interval of from 0.5mm to 2mm. [0018] Optionally, wherein the coil has a maximum length of 10 mm, a maximum width of 2 mm, and a maximum height of 1 mm. [0019] Optionally, wherein the integrated circuit includes memory configured to store a unique identifier (UID) for the IMD, the integrated circuit configured to combine the UID with the encoded pressure data to modulate the return NFC signal. [0020] Optionally, wherein the integrated circuit includes a temperature sensor configured to generate temperature data and memory configured to 15694WOO1 (013-0615PCT1) 4 PATENT store the temperature data, the integrated circuit configured to combine the temperature data with the encoded pressure data to modulate the return NFC signal. [0021] Optionally, wherein the IMD is an implantable sensor. [0022] Optionally, wherein the pressure data is indicative of the pressure in a lumen of a body. [0023] In accordance with embodiments herein, a method for generating signals to transmit from an implantable medical device (IMD) to a base unit includes receiving, via a coil communicatively connected to the IMD, near field communication (NFC) signals from the external device, and generating, via an integrated circuit coupled to a capacitive element, pressure data based on capacitance of the capacitive element. The capacitance of the capacitive element is configured to vary in response to changes in pressure. The method further includes encoding the pressure data to form encoded pressure data, and modulating a return signal, to be transmitted by the coil, based on the encoded pressure data. [0024] Optionally, wherein the integrated circuit includes a capacitance to digital (C/D) converter, and the method further includes measuring, using the C/D converter, the capacitance of the capacitive element, and digitally generating the pressure data based on the capacitance of the capacitive element. [0025] Optionally, the method further comprises applying serial encoding to the digital pressure data. [0026] Optionally, the method further comprises serially encoding the digital pressure data by applying serial encoding. [0027] Optionally, wherein the serial encoding is one of: Non-Return-to- Zero (NRZ) encoding, Non-Return-to-Zero-Inverted (NRZI) encoding, Return- to-Zero (RZ) encoding, or Manchester encoding. [0028] Optionally, wherein the C/D converter comprises a relaxation oscillator that includes a current source, a feedback loop, and a second 15694WOO1 (013-0615PCT1) 5 PATENT oscillator, and the method further includes charging and discharging the capacitive element using the current source, forming an oscillator with the feedback loop, and measuring, using the second oscillator, a duration of charge and discharge cycles of the capacitive element, the duration indicative of the capacitance of the capacitive element. [0029] Optionally, wherein the C/D converter comprises a relaxation oscillator that includes a current source, a first oscillator, and a second oscillator, and the method further includes charging and discharging the capacitive element using the current source, forming the first oscillator with a feedback loop, and measuring, using the second oscillator, a duration of charge and discharge cycles of the capacitive element, the duration indicative of the capacitance of the capacitive element. [0030] Optionally, wherein the modulating the return signal further includes modulating the return signal utilizing load impedance modulation and transitioning the load impedance between first and second states corresponding to data values in the encoded pressure data. [0031] Optionally, wherein the transition of the load impedance from the first state to the second state corresponds to a logical one in the encoded pressure data and the transition of the load impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data. [0032] Optionally, wherein the modulating the return signal further includes modulating the return signal utilizing load modulation to transition an impedance of the coil between first and second states corresponding to data values in the encoded pressure data. [0033] Optionally, the transition of the impedance from the first state to the second state corresponds to a logical one in the encoded pressure data and the transition of the impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data 15694WOO1 (013-0615PCT1) 6 PATENT [0034] Optionally, the method further includes encrypting the encoded pressure data to form encrypted pressure data and modulating the return signal based on the encrypted pressure data. [0035] Optionally, wherein the coil has a length selected within an interval of from 2mm to 20mm, a width selected within an interval of from 1mm to 4mm, and a height selected within an interval of from 0.5mm to 2mm. [0036] Optionally, wherein the coil has a maximum length of 10 mm, a maximum width of 2 mm, and a maximum height of 1 mm. [0037] Optionally, wherein the integrated circuit includes a memory, and the method further includes storing a unique identifier (UID) for the IMD in the memory and combining the UID with the encoded pressure data to modulate the return signal. [0038] Optionally, the wherein integrated circuit includes a temperature sensor configured to generate temperature data and memory configured to store the temperature data, the method further comprising combining the temperature data with the encoded pressure data to modulate the return signal. [0039] Optionally, wherein the IMD is an implantable sensor. [0040] Optionally, wherein the pressure data is indicative of the changes in the pressure in a lumen of a body. [0041] In accordance with embodiments herein, an IMD comprises a coil configured to receive near field communication (NFC) signals from an external device and to transmit return NFC signals to the external device. The IMD further comprises a capacitive element having a capacitance configured to vary in response to changes in pressure, and an integrated circuit coupled to the capacitive element. The integrated circuit includes a capacitance to digital (C/D) converter configured to measure the capacitance of the capacitive element and generate digital pressure data based on the capacitance of the capacitive element. The IMD further comprises at least one of a processor or 15694WOO1 (013-0615PCT1) 7 PATENT circuit configured to modulate the return NFC signal, to be transmitted by the coil, based on the digital pressure data. [0042] Optionally, wherein the at least one of a processor or circuit is further configured to encode the digital pressure data to form encoded pressure data, and modulate the return NFC signal, to be transmitted by the coil, based on the encoded pressure data. [0043] Optionally, wherein the at least one of a processor or circuit is further configured to serially encode the digital pressure data by applying serial encoding. [0044] Optionally, wherein the serial encoding is one of: Non-Return-to- Zero (NRZ) encoding, Non-Return-to-Zero-Inverted (NRZI) encoding, Return- to-Zero (RZ) encoding, or Manchester encoding. [0045] Optionally, wherein the at least one of a processor or circuit is further configured to encode the digital pressure data to form encoded pressure data and modulate the return NFC signal utilizing load modulation to transition an impedance of the coil between first and second states corresponding to data values in the encoded pressure data. [0046] Optionally, wherein the transition of the impedance from the first state to the second state corresponds to a logical one in the encoded pressure data and the transition of the impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data. [0047] Optionally, wherein the at least one of a processor or circuit is further configured to encode the digital pressure data to form encoded pressure data, and encrypt the encoded pressure data to form encrypted pressure data, the return NFC signal modulated based on the encrypted pressure data. [0048] Optionally, wherein the C/D converter comprises a relaxation oscillator that includes a current source configured to charge and discharge the capacitive element, a first oscillator formed by a feedback loop, and a second 15694WOO1 (013-0615PCT1) 8 PATENT oscillator configured to measure a duration of charge and discharge cycles of the capacitive element, the duration indicative of the capacitance of the capacitive element. [0049] Optionally, wherein the integrated circuit further includes memory configured to store a unique identifier (UID) for the IMD, wherein the at least one of a processor or circuit is further configured to encode the digital pressure data to form encoded pressure data, and combine the sensor UID with the encoded pressure data to modulate the return NFC signal. [0050] Optionally, wherein the integrated circuit includes a temperature sensor configured to generate temperature data and memory configured to store the temperature data, wherein the at least one of a processor or circuit is further configured to encode the digital pressure data to form encoded pressure data, and combine the temperature data with the encoded pressure data to modulate the return NFC signal. [0051] Optionally, wherein the IMD is an implantable sensor. [0052] Optionally, wherein the digital pressure data is indicative of a pressure in a lumen of a body. [0053] In accordance with embodiments herein, a method for generating signals to transmit from an IMD to an external device includes receiving, via a coil communicatively connected to the IMD, near field communication (NFC) signals from the external device and measuring, via a capacitance to digital (C/D) converter, capacitance of a capacitance element. The C/D converter is included within an integrated circuit coupled to the capacitive element. The capacitive element has the capacitance configured to vary in response to changes in pressure. The method further includes generating digital pressure data, via the C/D converter, based on the capacitance of the capacitive element. The method further includes modulating a return signal, using at least one of a processor or circuit included within the integrated circuit, based on the digital pressure data. 15694WOO1 (013-0615PCT1) 9 PATENT [0054] Optionally, the method further includes transmitting the return signal utilizing the coil. [0055] Optionally, the method further includes encoding the digital pressure data to form encoded pressure data, and modulating the return signal, to be transmitted by the coil, based on the encoded pressure data. [0056] Optionally, the method further includes serially encoding the digital pressure data by applying serial encoding. [0057] Optionally, the serial encoding is one of: Non-Return-to-Zero (NRZ) encoding, Non-Return-to-Zero-Inverted (NRZI) encoding, Return-to-Zero (RZ) encoding, or Manchester encoding. [0058] Optionally, the method further includes encoding the digital pressure data to form encoded pressure data, and modulating the return signal utilizing load modulation to transition an impedance of the coil between first and second states corresponding to data values in the encoded pressure data. [0059] Optionally, the transition of the impedance from the first state to the second state corresponds to a logical one in the encoded pressure data and the transition of the impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data. [0060] Optionally, the method further includes encoding the digital pressure data to form encoded pressure data, encrypting the encoded pressure data to form encrypted pressure data and modulating the return signal based on the encrypted pressure data. [0061] Optionally, the C/D converter comprises a relaxation oscillator including a current source, a first oscillator, and a second oscillator, and the method further includes charging and discharging the capacitive element using the current source, forming the first oscillator with a feedback loop, and measuring, using the second oscillator, a duration of charge and discharge cycles of the capacitive element, the duration indicative of the capacitance of the capacitive element. 15694WOO1 (013-0615PCT1) 10 PATENT [0062] Optionally, the method further includes storing a unique identifier (UID) for the IMD in a memory within or communicatively connected to the integrated circuit, encoding the digital pressure data to form encoded pressure data, and combining the UID with the encoded pressure data to modulate the return signal. [0063] Optionally, the method further includes encoding the digital pressure data to form encoded pressure data, generating temperature data with a temperature sensor included within the integrated circuit and combining the temperature data with the encoded pressure data to modulate the return signal. [0064] Optionally, wherein the IMD is an implantable sensor. [0065] Optionally, wherein the digital pressure data is indicative of the pressure in a lumen of a body. [0066] In accordance with embodiments herein, an implantable medical device (IMD) comprises a coil configured to receive near field communication (NFC) signals from an external device and to transmit return NFC signals to the external device, a capacitive element having a capacitance configured to vary in response to changes in pressure, and an integrated circuit coupled to the capacitive element. The integrated circuit includes at least one of a processor or circuit configured to generate pressure data based on the capacitance of the capacitive element, and modulate the return NFC signal, to be transmitted by the coil, based on the pressure data. [0067] The various embodiments described in the foregoing also apply to the IMD as defined above. [0068] In accordance with embodiments herein, a method for generating signals to transmit from an implantable medical device (IMD) to an external device, comprises receiving, via a coil communicatively connected with the IMD, near field communication (NFC) signals from the external device; generating, via an integrated circuit coupled to a capacitive element, pressure data based on 15694WOO1 (013-0615PCT1) 11 PATENT capacitance of the capacitive element, the capacitance of the capacitive element configured to vary in response to changes in pressure; and modulating a return signal, to be transmitted by the coil, based on the pressure data. [0069] The various embodiments described in the foregoing also apply to the method of the IMD as defined above. [0070] In accordance with embodiments herein, a method is disclosed for managing inductive communication between an implantable medical device (IMD) and an external device, the external device having an inductive external coil configured to be located proximate to a body, the IMD configured to be located within the body. The method includes transmitting, by the inductive external coil, inductive external near field communication (NFC) signals to an inductive IMD coil, and receiving, via the inductive external coil, inductive IMD NFC signals from the inductive IMD coil. The method further includes determining a characteristic of interest (COI) based on the inductive IMD NFC signals, and dynamically tuning at least one of the inductive external coil or the inductive IMD coil based on the COI. [0071] Optionally, wherein the COI is a voltage level associated with the inductive IMD NFC signals, and the dynamically tuning further includes dynamically tuning at least one of the inductive external coil or the inductive IMD coil based on a reflection coefficient associated with the COI. [0072] Optionally, wherein the COI is a voltage level of the inductive IMD NFC signals, and the dynamically tuning further includes dynamically tuning at least one of the inductive external coil or the inductive IMD coil based on a reflection coefficient of the COI. [0073] Optionally, wherein the COI is a voltage level associated with the inductive IMD NFC signals, and the dynamically tuning further includes changing at least one parameter of an external tunable matching network associated with the inductive external coil to minimize a reflection coefficient associated with the COI. 15694WOO1 (013-0615PCT1) 12 PATENT [0074] Optionally, wherein the COI is a voltage level of the inductive IMD NFC signals, and the dynamically tuning further includes changing at least one parameter of an external tunable matching network communicatively connected to the inductive external coil to minimize a reflection coefficient of the COI. [0075] Optionally, wherein the COI is a voltage level of the inductive IMD NFC signals, and the dynamically tuning further includes dynamically changing at least one parameter of an external tunable matching network communicatively connected to the inductive external coil to minimize a reflection coefficient of the COI. [0076] Optionally, wherein the changing at least one parameter of the external tunable matching network includes i) opening or closing a switch in the external tunable matching network, ii) adjusting an adjustable component in the external tunable matching network, or iii) increasing or decreasing an input voltage to the external tunable matching network to adjust an impedance of the inductive external coil. [0077] Optionally, wherein the COI is an IMD received signal strength indicator (RSSI), and the COI is included in a data packet transmitted by the inductive IMD coil. [0078] Optionally, wherein the COI is an IMD RSSI, and the method further includes determining an external RSSI associated with the inductive IMD NFC signals, and wherein the dynamically tuning further includes configuring a network configuration of an external tunable matching network associated with the inductive external coil or an IMD tunable matching network associated with the inductive IMD coil to maximize one of the IMD RSSI or external RSSI. [0079] Optionally, wherein the COI is an IMD RSSI, and the method further includes determining an external RSSI associated with the inductive IMD NFC signals, and wherein the dynamically tuning further includes configuring a network configuration of an external tunable matching network 15694WOO1 (013-0615PCT1) 13 PATENT communicatively connected to the inductive external coil or an IMD tunable matching network communicatively connected to the inductive IMD coil to maximize one of the IMD RSSI or external RSSI. [0080] Optionally, wherein the COI is an IMD RSSI, and the method further includes determining an external RSSI associated with the inductive IMD NFC signals, and wherein the dynamically tuning further includes dynamically configuring a network configuration of an external tunable matching network communicatively connected to the inductive external coil or an IMD tunable matching network communicatively connected to the inductive IMD coil to maximize one of the IMD RSSI or external RSSI. [0081] Optionally, the dynamically tuning further includes changing i) at least one parameter of an external tunable matching network associated with the inductive external coil or ii) at least one parameter of an IMD tunable matching network associated with the inductive IMD coil. [0082] Optionally, the dynamically tuning further includes changing i) at least one parameter of an external tunable matching network communicatively connected to the inductive external coil or ii) at least one parameter of an IMD tunable matching network communicatively connected to the inductive IMD coil. [0083] Optionally, the dynamically tuning further includes dynamically changing i) at least one parameter of an external tunable matching network communicatively connected to the inductive external coil or ii) at least one parameter of an IMD tunable matching network communicatively connected to the inductive IMD coil [0084] Optionally, wherein in response to changing the at least one parameter, the method further includes transmitting, by the inductive external coil, successive inductive external NFC signals to the inductive IMD coil, receiving, via the inductive external coil, successive inductive IMD NFC signals from the inductive IMD coil, the successive inductive IMD NFC signals including IMD data measurements, determining a successive COI based on the successive inductive 15694WOO1 (013-0615PCT1) 14 PATENT IMD NFC signals, and wherein the dynamically tuning further comprising dynamically tuning at least one of the inductive external coil or the inductive IMD coil based on the successive COI. [0085] Optionally, the method further includes setting an output power of the inductive external coil at an initial level, and in response to not receiving, via the inductive external coil, the inductive IMD NFC signals from the inductive IMD coil, increasing the output power of the inductive external coil. [0086] Optionally, wherein the COI is a phase difference between the inductive external NFC signals and the inductive IMD NFC signals, and the method further includes determining if the COI satisfies a phase difference threshold, and in response to satisfying the phase difference threshold, changing i) at least one parameter of an external tunable matching network associated with the inductive external coil or ii) at least one parameter of an IMD tunable matching network associated with the inductive IMD coil. [0087] Optionally, wherein the COI is a phase difference between the inductive external NFC signals and the inductive IMD NFC signals, and the method further includes determining if the COI satisfies a phase difference threshold, and in response to satisfying the phase difference threshold, changing i) at least one parameter of an external tunable matching network communicatively connected to the inductive external coil or ii) at least one parameter of an IMD tunable matching network communicatively connected to the inductive IMD coil. [0088] Optionally, the method further includes determining if an output power of the external device satisfies a power threshold, and in response to the output power satisfying the power threshold, decreasing the output power. [0089] Optionally, the method further includes, in response to a decrease in the output power of the external device, changing at least one parameter of an external tunable matching network communicatively connected to the inductive external coil, and transmitting, by the inductive external coil, successive 15694WOO1 (013-0615PCT1) 15 PATENT inductive external NFC signals to the inductive IMD coil. The method further includes receiving, via the inductive external coil, successive inductive IMD NFC signals from the inductive IMD coil, the successive inductive IMD NFC signals including IMD data measurements, determining a successive COI based on the successive inductive IMD NFC signals, and wherein the dynamically tuning further comprising dynamically tuning the inductive external coil based on the successive COI. [0090] Optionally, wherein in response to a time interval being satisfied, the method further includes evaluating i) an IMD RSSI, ii) an external RSSI, iii) a reflection coefficient of or associated with the COI, iv) a phase difference between the inductive external NFC signals and the inductive IMD NFC signals, or v) an output power of the external device. [0091] Optionally, the inductive IMD NFC signals include IMD data measurements. [0092] In accordance with embodiments herein, an external device for managing inductive communication between an implantable medical device (IMD) and the external device is provided. The external device includes an inductive external coil configured to transmit inductive external near field communication (NFC) signals to the IMD and receive inductive IMD NFC signals from an inductive IMD coil communicatively connected to the IMD. The external device further includes at least one of a processor or circuit configured to utilize the inductive external coil to transmit the inductive external NFC signals to the inductive IMD coil, receive, via the inductive external coil, inductive IMD NFC signals from the inductive IMD coil, determine a characteristic of interest (COI) based on the inductive IMD NFC signals, and dynamically tune at least one of the inductive external coil or the inductive IMD coil based on the COI. [0093] Optionally, the inductive external coil further comprises an external tunable matching network, wherein the dynamically tune the inductive external coil 15694WOO1 (013-0615PCT1) 16 PATENT further comprises changing at least one parameter of an external matching network configuration associated with the external tunable matching network. [0094] Optionally, the inductive external coil further comprises an external tunable matching network, wherein the dynamically tune the inductive external coil further comprises changing at least one parameter of an external matching network configuration of the external tunable matching network. [0095] Optionally, the inductive external coil further includes an external tunable matching network comprising i) a switch communicatively interconnected with one or more components or ii) an adjustable component, wherein the at least one of a processor or circuit is further configured to direct the switch to electrically connect or disconnect the one or more components or adjust the adjustable component, utilize the inductive external coil to transmit successive inductive external NFC signals to the inductive IMD coil, receive, via the inductive external coil, successive inductive IMD NFC signals from the inductive IMD coil, the successive inductive IMD NFC signals including IMD data measurements, and determine a successive characteristic of interest (COI) based on the successive inductive IMD NFC signals. [0096] Optionally, wherein the inductive external coil further includes an external tunable matching network comprising i) at least one adjustable component or ii) at least one switch, wherein the at least one switch is configured to electrically connect and disconnect at least one component of the external tunable matching network. [0097] Optionally, wherein the inductive external coil further comprises an external tunable matching network that includes a plurality of switches, wherein each of the plurality of switches is configured to electrically connect and disconnect one or more components, wherein, in response to the COI comprising an IMD RSSI, the at least one of a processor or circuit is further configured to dynamically tune the inductive external coil by opening or closing at least one of the plurality of switches to adjust the IMD RSSI. 15694WOO1 (013-0615PCT1) 17 PATENT [0098] Optionally, wherein the inductive external coil includes an external tunable matching network including one or more of i) a pi-match network, ii) an L-match network, iii) a T-match network, iv) a combination of two of more of pi- match, L-match, or T-match networks, v) a series of two or more of pi-match, L-match, or T-match network, or vi) an adjustable component. [0099] Optionally, wherein the inductive external coil is conformable. [00100] Optionally, wherein the inductive IMD NFC signals include data measurements. [00101] Optionally, wherein the IMD is a pressure sensor and the inductive IMD NFC signals include pressure measurements. [00102] Optionally, wherein the inductive external coil is configured to be located proximate to a body, the IMD configured to be located within the body. [00103] Optionally, wherein the IMD is an implantable sensor. [00104] Optionally, wherein the IMD is an implantable sensor configured to generate pressure data indicative of pulmonary arterial pressure. [00105] Optionally, wherein the IMD is an active device configured to deliver therapy to a patient. [00106] Optionally, wherein the IMD is a passive device configured to generate data associated with a patient. [00107] Optionally, wherein the COI is a voltage level of the inductive IMD NFC signals, and wherein the dynamically tune further comprises dynamically tune at least one of the inductive external coil or the inductive IMD coil based on a reflection coefficient of the COI. [00108] Optionally, wherein the inductive external coil further comprises an external tunable matching network, wherein the COI is a voltage level of the inductive IMD NFC signals, wherein the dynamically tune further comprising changing at least one parameter of the external tunable matching network to minimize a reflection coefficient of the COI. 15694WOO1 (013-0615PCT1) 18 PATENT [00109] Optionally, wherein the changing at least one parameter of the external tunable matching network comprises i) opening or closing a switch in the external tunable matching network, ii) adjusting an adjustable component in the external tunable matching network, or iii) increasing or decreasing an input voltage to the external tunable matching network to adjust an impedance of the inductive external coil. [00110] Optionally, wherein the inductive external coil further comprises an external tunable matching network comprising a plurality of switches, wherein each of the plurality of switches is configured to electrically connect and disconnect one or more components, wherein, in response to the COI comprising an IMD RSSI, the at least one of a processor or circuit is further configured to determine an external RSSI; and dynamically tune the inductive external coil by opening or closing at least one of the plurality of switches to maximize one of the IMD RSSI or external RSSI. [00111] Optionally, wherein the COI is a phase difference between the inductive external NFC signals and the inductive IMD NFC signals, wherein the at least one of the processor or circuit further configured to determine if the COI satisfies a phase difference threshold; and in response to satisfying the phase difference threshold, change i) at least one parameter of an external tunable matching network communicatively connected to the inductive external coil or ii) at least one parameter of an IMD tunable matching network communicatively connected to the inductive IMD coil. [00112] Optionally, wherein the at least one of the processor or circuit further configured to determine if an output power of the external device satisfies a power threshold; and in response to the output power satisfying the power threshold, decrease the output power. [00113] Optionally, wherein in response to a time interval being satisfied, the at least one of the processor or circuit further configured to evaluate i) an IMD RSSI, ii) an external RSSI, iii) a reflection coefficient associated with the COI, iv) 15694WOO1 (013-0615PCT1) 19 PATENT a phase difference between the inductive external NFC signals and the inductive IMD NFC signals, or v) an output power of the external device. BRIEF DESCRIPTION OF THE DRAWINGS [00114] Figure 1A illustrates a system that includes an implantable medical device (IMD), such as an implantable pressure sensor, and an external device implemented in accordance with embodiments herein. [00115] Figure 1B illustrates possible configurations wherein one or more IMD, such as an implantable pressure sensor(s), is implanted within the heart in accordance with embodiments herein. [00116] Figure 1C illustrates an embodiment in which an IMD, such as an implantable pressure sensor, and a second IMD, such as an implantable cardiac monitor, are implanted within a patient in accordance with embodiments herein. [00117] Figure 2A illustrates a system wherein an external device uses near field communication (NFC) to power and receive data from the IMD in accordance with embodiments herein. [00118] Figure 2B illustrates a cross-sectional view of an example of a MEMS capacitive sensor formed in accordance with embodiments herein. [00119] Figure 3A illustrates a block diagram of an integrated circuit within the IMD in accordance with embodiments herein. [00120] Figure 3B illustrates an exemplary capacitance to digital converter implemented as a modified version of a relaxation oscillator in accordance with embodiments herein. [00121] Figure 3C illustrates an implementation of the capacitance to digital converter with transistors in accordance with embodiments herein. [00122] Figure 4A shows a top view of the IMD (e.g., pressure sensor) that includes the integrated circuit that is powered by and communicates with the external device using NFC in accordance with embodiments herein. 15694WOO1 (013-0615PCT1) 20 PATENT [00123] Figure 4B shows an exploded view of the IMD (e.g., pressure sensor) in accordance with embodiments herein. [00124] Figures 4C and 4D show isometric views of the IMD (e.g., pressure sensor) without and with the top glass included, respectively, in accordance with embodiments herein. [00125] Figure 4E shows a portion of the IMD (e.g., pressure sensor) having direct wirebond interconnections to the integrated circuit in accordance with embodiments herein. [00126] Figure 4F shows the portion of the IMD (e.g., pressure sensor) as discussed in Figure 4D having a resonant capacitor in accordance with embodiments herein. [00127] Figures 4G and 4H illustrate views wherein the integrated circuit is mounted to a printed circuit board (PCB) in accordance with embodiments herein. [00128] Figures 4I and 4J show top and isometric views, respectively, of the IMD (e.g., pressure sensor) that utilizes tab welding as discussed in Figure 4G in accordance with embodiments herein. [00129] Figure 4K illustrates an exploded view of the coil and sensor body wherein the integrated circuit (not shown) is mounted to the bottom side of the PCB in accordance with embodiments herein. [00130] Figure 4L shows a cross-sectional view of the IMD (e.g., pressure sensor) in accordance with embodiments herein. [00131] Figure 4M is a top view of the IMD (e.g., pressure sensor) showing the interconnects directly attaching to the integrated circuit in accordance with embodiments herein. [00132] Figure 5 illustrates an example process flow for calibrating the IMD (e.g., pressure sensor) in accordance with embodiments herein. [00133] Figure 6 illustrates an example process flow for identifying and baselining the IMD (e.g., pressure sensor) during implantation in accordance with embodiments herein. 15694WOO1 (013-0615PCT1) 21 PATENT [00134] Figure 7 illustrates an example process flow for acquiring pressure readings sensed by the IMD (e.g., pressure sensor) in accordance with embodiments herein. [00135] Figure 8 illustrates a digital healthcare system implemented in accordance with embodiments herein. [00136] Figure 9A illustrates a system wherein the external device uses near field communication (NFC) to power and receive data from the IMD in accordance with embodiments herein. [00137] Figure 9B illustrates a block diagram of the integrated circuit within the IMD in accordance with embodiments herein. [00138] Figure 9C illustrates an exemplary external device for communicating with an IMD implanted within a body in accordance with embodiments herein. [00139] Figure 10A illustrates an example of an IMD matching network communicatively connected to the IMD coil/antenna and an external matching network communicatively connected to the external coil/antenna, the matching networks having a simple pi-match network topology in accordance with embodiments herein. [00140] Figure 10B illustrates an example wherein the external matching network of the external device is an L-match topology in accordance with embodiments herein. [00141] Figure 10C illustrates an example wherein the external matching network of the external device is a T-match topology in accordance with embodiments herein. [00142] Figure 10D illustrates an example of the IMD matching network and the external matching network having a back-to-back L-match network topology in accordance with embodiments herein. 15694WOO1 (013-0615PCT1) 22 PATENT [00143] Figure 11 illustrates an example process flow for setting an output power of the external device (e.g., reader) for acquiring IMD data measurements, sensed and/or determined by the IMD, in accordance with embodiments herein. [00144] Figure 12 illustrates an example process flow for dynamically receiving IMD data measurements and tuning the external coil/antenna to minimize the reflection coefficient in accordance with embodiments herein. [00145] Figure 13 illustrates an example process flow for dynamically receiving IMD data measurements and tuning the external coil/antenna based on IMD RSSI and external device RSSI in accordance with embodiments herein. [00146] Figure 14 illustrates an example process flow for dynamically receiving IMD data measurements and tuning the external coil/antenna to optimize the phase difference between transmit and receive signals in accordance with embodiments herein. [00147] Figure 15 illustrates an example process flow for tuning the external coil/antenna based on a time interval in accordance with embodiments herein. [00148] Figure 16 illustrates an example process flow for tuning the external coil/antenna based on the phase difference between the transmit and receive signals in accordance with embodiments herein. [00149] Figure 17 illustrates an example process flow for tuning the external coil/antenna based on the IMD RSSI and/or the external RSSI in accordance with embodiments herein. [00150] Figure 18 illustrates an example process flow for tuning the external coil/antenna based on output power of the external device in accordance with embodiments herein. DETAILED DESCRIPTION [00151] It will be readily understood that the components of the embodiments as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations in addition to the described 15694WOO1 (013-0615PCT1) 23 PATENT example embodiments. Thus, the following more detailed description of the example embodiments, as represented in the figures, is not intended to limit the scope of the embodiments, as claimed, but is merely representative of example embodiments. [00152] Reference throughout this specification to “one embodiment” or “an embodiment” (or the like) means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” or the like in various places throughout this specification are not necessarily all referring to the same embodiment. [00153] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that the various embodiments can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obfuscation. The following description is intended only by way of example, and simply illustrates certain example embodiments. [00154] The methods described herein may employ structures or aspects of various embodiments (e.g., systems, devices and/or methods) discussed herein. In various embodiments, certain operations may be omitted or added, certain operations may be combined, certain operations may be performed simultaneously, certain operations may be performed concurrently, certain operations may be split into multiple operations, certain operations may be performed in a different order, or certain operations or series of operations may be re-performed in an iterative fashion. It should be noted that other methods may be used in accordance with an embodiment herein. Further, wherein indicated, the methods may be fully or partially implemented by one or more processors or 15694WOO1 (013-0615PCT1) 24 PATENT integrated circuits of one or more devices or systems. While the operations of some methods may be described as performed by the processor(s) of one device, additionally, some or all of such operations may be performed by the processor(s) of another device described herein. Terms [00155] The term “PA” shall mean pulmonary artery. [00156] The term “PAP” shall mean pulmonary arterial pressure. [00157] The terms “non-inductive capacitive element” and “non-L capacitive element” shall mean a capacitive element that is not connected to an inductive element upstream of a capacitance to digital converter unit. [00158] The terms “antenna”, “inductive coil”, and “coil” are used interchangeably herein and shall mean a device capable of telemetry and powering at various frequencies, including 13.56 MHz for near field communication. [00159] The terms “dynamic” and dynamically” shall mean that operations can occur simultaneously and/or in real-time. For example, an external device can receive packets from an IMD that include IMD data measurements (e.g., pressure data), calibration information, IMD identification information, IMD matching network configuration information, etc., while dynamically determining characteristics of interest of (e.g., associated with) an external and/or an IMD NFC signal, adjusting one or more parameter of or associated with an antenna/coil matching network (e.g., external tunable matching network, IMD tunable matching network), determining and/or adjusting an output power level of an external device, etc. In some cases, dynamically tuning the external and/or IMD coil (e.g., antenna) can be accomplished in real-time, such as during a beginning, middle, or end of a data exchange session, which includes an interval of time during which the IMD sends data measurements to the external device. 15694WOO1 (013-0615PCT1) 25 PATENT [00160] The terms “characteristic of interest” and “COI” are used interchangeably herein. Non-limiting examples of COIs associated with NFC signals include power level (decibels), voltage level, and amplitude. [00161] The terms “tuning” and “tune” shall mean changing at least one parameter of a matching network communicatively connected to an antenna/coil to improve and/or optimize for the system configuration and environment at a particular time to improve and/or optimize communication factors, e.g., coil (e.g., antenna) matching, frequency, noise, power level. [00162] The terms “data exchange session” and “collection session” are used interchangeably herein and shall mean an interval of time, during which communication between the external device and the IMD is established. During at least a portion of the collection session, the IMD is collecting IMD data measurements and transmitting the IMD data measurements to the external device via NFC. In addition, the IMD can receive information and/or commands from the external device, and the IMD can transmit other information, such as serial number, error codes, temperature measurements, and the like to the external device. Further, the external device and/or IMD can tune an external coil/antenna and/or an IMD coil/antenna during the collection session. [00163] The term “course sweep” indicates a sweep over a range that does not evaluate each possible configuration of a matching network of a coil/antenna. The term “fine sweep” indicates a sweep over a range that evaluates a greater number of the possible configurations than the course sweep over a given range. A course sweep and fine sweep can be evaluated over an entire possible range or a sub-set of the entire possible range. In accordance with embodiments herein, the sweeps can be accomplished by changing at least one parameter at a time of a matching network communicatively connected to a coil/antenna. [00164] The terms “doctor” and “clinician” shall mean medical personnel, nonlimiting examples of which include doctors, nurses, hospital or clinical staff, 15694WOO1 (013-0615PCT1) 26 PATENT pharmacist, physical therapist, and any other person trained or licensed to provide medical assistance to a patient. [00165] The term “hermetic”, as used herein, shall refer to a sealed interface at least with respect to entry or escape of air and/or bodily fluids. [00166] The terms “processor,” “a processor”, “one or more processors” and “the processor” shall mean one or more processors. The one or more processors may be implemented by one, or by a combination of more than one implantable medical device, a wearable device, a local device, a remote device, a server computing device, a network of server computing devices and the like. The one or more processors may be implemented at a common location or at distributed locations. The one or more processors may implement the various operations described herein in a serial or parallel manner, in a shared-resource configuration and the like. [00167] The term “external device” shall mean a commercial wireless device (e.g., a tablet computer, a smartphone, a laptop computer) and/or a specialized wireless device, such as a programmer or bedside monitor. A patient, using an application, button, selection, etc., on the external device, may trigger the external device to transmit near field communication (NFC) signals from the external device to the IMD. The NFC signals can power the IMD, transmit information to the IMD, and direct the IMD to save information and settings. The NFC signals received by the external device can include information transmitted by the IMD. [00168] The terms “cardiac activity signal”, “cardiac activity signals”, “CA signal” and “CA signals” (collectively “CA signals”) refer to measured signals indicative of cardiac activity by a region or chamber of interest. For example, the CA signals may be indicative of impedance, electrical or mechanical activity by one or more chambers (e.g., left or right ventricle, left or right atrium) of the heart and/or by a local region within the heart (e.g., impedance, electrical or mechanical activity at the AV node, along the septal wall, within the left or right bundle branch, within the Purkinje fibers). The cardiac activity may be normal/healthy or 15694WOO1 (013-0615PCT1) 27 PATENT abnormal/arrhythmic. An example of CA signals includes EGM signals. Electrical based CA signals refer to an analog or digital electrical signal recorded by two or more electrodes, where the electrical signals are indicative of cardiac activity. Heart sound (HS) based CA signals refer to signals output by a heart sound sensor such as an accelerometer, where the HS based CA signals are indicative of one or more of the S1, S2, S3 and/or S4 heart sounds. Impedance based CA signals refer to impedance measurements recorded along an impedance vector between two or more electrodes, where the impedance measurements are indicative of cardiac activity. [00169] The term “health care system” refers to a system that includes equipment for measuring health parameters, and communication pathways from the equipment to secondary devices. The secondary devices may be at the same location as the equipment, or remote from the equipment at a different location. The communication pathways may be wired, wireless, over the air, cellular, in the cloud, etc. In one example, the healthcare system provided may be one of the systems described in U.S. published application US20210020294A1 entitled METHODS DEVICE AND SYSTEMS FOR HOLISTIC INTEGRATED HEALTHCARE PATIENT MANAGEMENT, filed July 16, 2020, the entire contents of which are incorporated in full herein. Other patents that describe example monitoring systems include U.S. Pat. No. 6,572,557 entitled SYSTEM AND METHOD FOR MONITORING PROGRESSION OF CARDIAC DISEASE STATE USING PHYSIOLOGIC SENSORS, filed Dec.21, 2000.; U.S. Pat. No.6,480,733 entitled METHOD FORMONITORING HEART FAILURE filed Dec.17, 1999; U.S. Pat. No.7,272,443 entitled SYSTEM AND METHOD FOR PREDICTING A HEART CONDITION BASED ON IMPEDANCE VALUES USING AN IMPLANTABLE MEDICAL DEVICE, filed Dec. 14, 2004; U.S. Pat. No. 7,308,309 entitled DIAGNOSING CARDIAC HEALTH UTILIZING PARAMETER TREND ANALYSIS, filed Jan.11, 2005; and U.S. Pat. No.6,645,153 entitled SYSTEM AND METHOD FOR EVALUATING RISK OF MORTALITY DUE TO CONGESTIVE HEART 15694WOO1 (013-0615PCT1) 28 PATENT FAILURE USING PHYSIOLOGIC SENSORS, filed Feb.7, 2002 et. al., the entire contents of which are incorporated in full herein. [00170] The term “IMD data” shall refer to any and all types of information and signals conveyed (e.g., transmitted) from an implantable medical device to a local or remote external device. Non-limiting examples of IMD data include cardiac activity signals (e.g., intracardiac electrogram or IEGM signals), impedance signals (e.g., cardiac, pulmonary or transthoracic impedances), accelerometer signatures (e.g., activity signals, posture/orientation signals, heart sounds), pulmonary arterial pressure signals, digital signals representative of pressure signals, mechanical circulatory support (MCS) rpm levels, MCS flow rates, device alerts and the like. [00171] The term “IMD” shall mean an implantable medical device. The terms “IMD”, “implantable pressure sensor”, “implantable sensor”, and “sensor” can be used interchangeably herein. Embodiments may be implemented in connection with one or more implantable medical devices (IMDs). Non-limiting examples of IMDs include one or more of neurostimulator devices, implantable leadless monitoring and/or therapy devices, and/or alternative implantable medical devices. For example, the IMD may represent a subcutaneous cardioverter defibrillator, cardiac monitoring device, pacemaker, cardioverter, cardiac rhythm management device, defibrillator, neurostimulator, leadless monitoring device, leadless pacemaker, left atrial or pulmonary artery pressure sensor, blood glucose monitoring device, and the like. The IMD may measure electrical, mechanical, impedance, blood glucose, or pressure information. For example, the IMD may include one or more structural and/or functional aspects of the device(s) described in U.S. Patent Number 9,333,351, entitled “Neurostimulation Method And System To Treat Apnea” issued May 10, 2016 and U.S. Patent Number 9,044,610, entitled “System And Methods For Providing A Distributed Virtual Stimulation Cathode For Use With An Implantable Neurostimulation System” issued June 02, 2015, and U.S. patent application publication no. US 2023/0109023, entitled “System and Method for Intra-Body Communication of Sensed Physiologic Data”, filed August 15694WOO1 (013-0615PCT1) 29 PATENT 18, 2022, which are hereby incorporated by reference. The IMD may monitor transthoracic impedance, such as implemented by the CorVue algorithm offered by St. Jude Medical. Additionally or alternatively, the IMD may include one or more structural and/or functional aspects of the device(s) described in U.S. Patent Number 9,216,285, entitled “Leadless Implantable Medical Device Having Removable And Fixed Components” issued December 22, 2015 and U.S. Patent Number 8,831,747, entitled “Leadless Neurostimulation Device And Method Including The Same” issued September 09, 2014, which are hereby incorporated in full by reference herein. Additionally or alternatively, the IMD may include one or more structural and/or functional aspects of the device(s) described in U.S. Patent Number 8,391,980, entitled “Method And System For Identifying A Potential Lead Failure In An Implantable Medical Device” issued March 05, 2013, and U.S. Patent Number 9,232,485, entitled “System And Method For Selectively Communicating With An Implantable Medical Device” issued January 05, 2016, which are hereby incorporated in full by reference herein. Additionally or alternatively, the IMD may be a subcutaneous IMD that includes one or more structural and/or functional aspects of the device(s) described in U.S. Patent Number 10,765,860, entitled “Subcutaneous Implantation Medical Device With Multiple Parasternal-Anterior Electrodes” issued September 08, 2020; U.S. Patent Number 10,722,704, entitled “Implantable Medical Systems And Methods Including Pulse Generators And Leads” issued July 28, 2020; U.S. Patent Number 11,045,643, entitled “Single Site Implantation Methods For Medical Devices Having Multiple Leads”, issued June 29, 2021; and U.S. published application US2021/0330239A1, entitled “Method and system for adaptive-sensing of electrical cardiac signals” filed March 4, 2021, which are hereby incorporated by reference in their entireties. Additionally or alternatively, the IMD may be a leadless cardiac monitor (ICM) that includes one or more structural and/or functional aspects of the device(s) described in U.S. Patent 9,949,660, entitled, “METHOD AND SYSTEM TO DISCRIMINATE RHYTHM PATTERNS IN CARDIAC 15694WOO1 (013-0615PCT1) 30 PATENT ACTIVITY,” which is expressly incorporated herein by reference. Further, one or more combinations of IMDs may be utilized from the above incorporated patents and applications in accordance with embodiments herein. Embodiments may be implemented in connection with one or more subcutaneous implantable medical devices (S-IMDs). The IMD may represent a device that utilizes an external power source, an entirely mechanical device, and/or an active device that includes an internal power source. The IMD may be an active IMD and deliver some type of therapy/treatment and/or provide mechanical circulatory support, or be a passive IMD, monitoring one or more physiologic characteristics of interest (e.g., PAP, CA signals, impedance, heart sounds.) Additionally, the IMD may be a device that utilizes an external power source while also utilizing active components to monitor physiologic characteristics of interest. [00172] The “implantable pressure sensor” and “implantable sensor” disclosed herein may implement one or more structural and/or functional aspects of the device(s) described in U.S. patent 11,033,192, filed November 16, 2018, and entitled “Wireless Sensor for Measuring Pressure”; U.S. patent 10,143,388, filed Jun.8, 2015, titled "Method of Manufacturing Implantable Wireless Sensor for In Vivo Pressure Measurement”; U.S. patent 9,078,563, filed Nov.4, 2009, titled "Method of Manufacturing Implantable Wireless Sensor for In Vivo Pressure Measurement"; U.S. patent 7,621,036, filed on Aug. 16, 2005, titled "Method of Manufacturing Implantable Wireless Sensor for In Vivo Pressure Measurement"; and U.S. published patent application 2006/0287602, filed Jun. 21, 2005, titled "Implantable Wireless Sensor for In Vivo Pressure Measurement," which are expressly incorporated herein by reference in their entireties. [00173] Additionally or alternatively, the processes, systems, components, etc., described herein may be implemented utilizing all or portions of the structural and/or functional aspects of the methods and systems described in US published application number 2014/0330143, filed May 2, 2014, titled “Method and system for treating cardiovascular disease”; US published application number 15694WOO1 (013-0615PCT1) 31 PATENT 2014/0288459, filed March 25, 2013, titled “Ventricular shunt system and method”; US published application number 2014/0288085, filed March 17, 2014, titled “Methods for the Treatment of Cardiovascular Conditions“; US published application number 2014/0275861, filed March 17, 2014, titled “Ambulatory sensing system and associated methods”; US published application number 2014/0155769, filed November 21, 2013, titled “Devices, Systems, and Methods for Pulmonary Arterial Hypertension (PAH) Assessment and Treatment”; US published application number 2014/0084943, filed September 21, 2012, titled “Strain monitoring system and apparatus; US published application number 2014/0088994, filed September 23, 2013, titled “Method and system for trend- based patient management”; US published application number 2013/0245469, filed March 15, 2013, titled “Pulmonary Arterial Hemodynamic Monitoring for Chronic Obstructive Pulmonary Disease Assessment and Treatment”; US published application number 2015/0133796, filed November 6, 2014, titled “Systems and methods for using physiological information”; US patent 8,669,770, filed November 15, 2010, titled “Selectively actuating wireless, passive implantable sensor”; US published application number 2013/0296721, January 29, 2013, titled “Hypertension System And Method”; US patent 8,264,240, July 20, 2009, titled “Physical property sensor with active electronic circuit and wireless power and data transmission”; US patent 8,159,348, filed February 26, 2009, titled “Communication system with antenna box amplifier”; US patent 7,667,547, filed August 22, 2007, titled “Loosely-coupled oscillator”; US patent 7,966,886, filed October 9, 2009, titled “Method and apparatus for measuring pressure inside a fluid system”; US patent 8,665,086, January 4, 2012, titled “Physiological data acquisition and management system for use with an implanted wireless sensor”; US patent 7,908,018, September 6, 2006, titled “Flexible electrode”; US patent 7,909,770, July 3, 2007, titled “Method for using a wireless pressure sensor to monitor pressure inside the human heart”; US patent 7,812,416, filed May 15, 2007, titled “Methods and apparatus having an integrated circuit attached to fused 15694WOO1 (013-0615PCT1) 32 PATENT silica”; US patent 7,829,363, May 10, 2007, titled “Method and apparatus for microjoining dissimilar materials”; US published application number 2007/0199385, filed November 17, 2006, titled “Capacitor electrode formed on surface of integrated circuit chip”; US patent 7,748,277, filed October 18, 2006, titled “Hermetic chamber with electrical feedthroughs”; US published application number 2007/0158769, filed October 12, 2006, titled “Integrated CMOS-MEMS technology for wired implantable sensors”; US patent 7,710,103, filed January 7, 2009, titled “Preventing false locks in a system that communicates with an implanted wireless sensor”; US patent 8,896,324, filed September 26, 2011, titled “System, apparatus, and method for in-vivo assessment of relative position of an implant”; US published application number 2012/0016207, filed September 26, 2011, titled “Electromagnetically coupled hermetic chamber”; US patent 8,355,777, filed September 19, 2011, titled “Apparatus and method for sensor deployment and fixation”; US patent 7,854,172, filed February 17, 2009, titled “Hermetic chamber with electrical feedthroughs”; US patent 7,147,604, filed August 7, 2002, titled “High Q factor sensor”; US patent 7,618,363, filed August 6, 2003, titled “Hydraulically actuated artificial muscle for ventricular assist”; US patent 7,699,059, filed January 22, 2002, titled “Implantable wireless sensor”; US patent 7,481,771, filed July 7, 2007, titled “Implantable wireless sensor for pressure measurement within the heart”; US published application number 2022/0079456, filed October 21, 2021, titled “System and method for calculating a lumen pressure utilizing sensor calibration parameters”; PCT application number PCT/US2024/052734, filed October 24, 2024, claiming priority to US serial number 63/596,402, filed November 6, 2023, titled “System and Method for Diastolic- Enhanced Systolic Peak Detection”; US patent 11,832,920, filed June 5, 2020, titled “Devices, Systems, and Methods for Pulmonary Arterial Hypertension (PAH) Assessment and Treatment”; US patent 9,792,469, filed October 17, 2016, titled “Wireless Physical Property Sensor with Digital Communications”; US patent 8,237,451, filed April 1, 2011, titled “Communicating with an implanted wireless 15694WOO1 (013-0615PCT1) 33 PATENT sensor”; and US patent 9,653,926, filed May 21, 2015, titled “Physical Property Sensor with Active Electronic Circuit and Wireless Power and Data Transmission”, U.S. Patent No. 9,265,428, filed July 18, 2008, titled “Implantable Wireless Sensor”; U.S. Patent No.8,278,941, April 1, 2009, titled “Strain Monitoring System and Apparatus”; U.S. Patent No.8,026,729, filed April 1, 2009, titled “System and Apparatus for In-Vivo Assessment of Relative Position of an Implant”; U.S. Patent No.8,870,787, filed July 24, 2009, titled “Ventricular Shunt System and Method”; US Patent No.9,955,289, filed September 14, 2016, titled “Systems and methods for implantable medical devices including near field communications”; and US Patent No. 9,288,614, filed March 3, 2015, titled “Systems and methods for initiating a communication link between an implantable medical device and an external device”, which are hereby incorporated by reference in their entireties. [00174] Additionally or alternatively, the processes, systems, components, etc., described herein may be implemented utilizing all or portions of the structural and/or functional aspects of the methods and systems described in US published application number 2024/0053324, filed September 6, 2023, titled “Systems, devices, and methods for wireless communications in analyte monitoring systems”; US published application number 2024/0065586, filed August 28, 2023, titled “SYSTEM, APPARATUS, AND DEVICES FOR ANALYTE MONITORING”; US published application number 2023/0389838, filed August 15, 2023, titled “SYSTEMS, DEVICES, AND METHODS RELATED TO THE INDIVIDUALIZED CALIBRATION AND/OR MANUFACTURING OF MEDICAL DEVICES”; US published application number 2023/0404441, filed April 25, 2023, titled “SYSTEMS, DEVICES, AND METHODS FOR MEAL-RELATED ANALYTE RESPONSE MONITORING”; US published application number 2023/0248272, filed February 6, 2023, titled “SYSTEMS, DEVICES, AND METHODS FOR AN ANALYTE SENSOR”; US published application number 2023/0157590, filed January 9, 2023, titled “FOCUSED STERILIZATION AND STERILIZED SUBASSEMBLIES FOR ANALYTE MONITORING SYSTEMS”; US published 15694WOO1 (013-0615PCT1) 34 PATENT application number 2023/0096239, filed September 29, 2022, titled “Mobile Application Updates for Analyte Data Receiving Devices”; US Patent No. 11,571149, filed September 28, 2022, titled “Systems, devices, and methods for energy efficient electrical device activation”; US published application number 2023/0027588; filed July 20, 2022, titled “Over-the-Air Programming of Sensing Devices”; US published application number 2022/0369926, filed October 28, 2020, titled “SYSTEMS, DEVICES, AND METHODS FOR SENSOR COMMUNICATIONS”; US published application number 2023/0000350, filed April 19, 2022, titled “SYSTEMS, DEVICES, AND METHODS FOR INTEGRATION OF AN ANALYTE DATA READER AND MEDICATION DELIVERY DEVICE”; US published application number 2022/0240819, filed January 28, 2022, titled “THIRD PARTY ANALYTE MONITORING”; US published application number 2022/0116395, filed December 23, 2021, titled “SYSTEMS, DEVICES, AND METHODS FOR AUTHENTICATION IN AN ANALYTE MONITORING ENVIRONMENT”; Mexican published application number 2021/012625, filed April 17, 2020, titled “Systems, devices, and methods for handling wireless communications in an analyte monitoring environment”; Canadian published application number 3191110, filed September 17, 2021, titled “Digital and user interfaces for analyte monitoring systems”; Canadian published application number 3186875, filed September 14, 2021, titled “System, apparatus, and devices for analyte monitoring”; US published application number 2022/0070666, filed September 1, 2023, titled “SECURED COMMUNICATIONS IN MEDICAL MONITORING SYSTEMS”; Canadian published application number 3196957, filed August 31, 2021, titled “Embedded systems in medical monitoring systems”; US published application number 2022/0167885, filed July 1, 2021, titled “SYSTEMS, DEVICES, AND METHODS FOR ESTABLISHING AND/OR MAINTAINING SYNCHRONIZATION BETWEEN ENTITIES IN AN ANALYTE MONITORING ENVIRONMENT”; US published application number 2020/0100676, filed December 2, 2019, titled “Medical Devices and Methods”; US 15694WOO1 (013-0615PCT1) 35 PATENT Patent No. 10,742,269, filed August 30, 2019, titled “Systems, devices, and methods utilizing secondary communication systems”; US published application number 2019/0354674, filed June 7, 2019, titled “APPLICATION INTERFACE AND DISPLAY CONTROL IN AN ANALYTE MONITORING ENVIRONMENT”; US published application number 2018/0199813, filed March 7, 2018, “SYSTEMS, DEVICES, AND METHODS FOR MONITORING MEDICAL DEVICES”; US Patent No.10,290,208, filed October 17, 2017, titled “Methods for enabling a disabled capability of a medical device”; US Patent No.10,488,362, filed July 17, 2017, titled “Paper substrate diagnostic apparatus and related methods and systems”; US published application number 2018/0007139, filed June 30, 2017, titled “MANAGEMENT OF MULTIPLE DEVICES WITHIN AN ANALYTE MONITORING ENVIRONMENT”; US Patent No. 10,361,574, filed January 20, 2017, titled “Systems, devices, and methods for control of a power supply connection”; and US Patent No.9,907,470, filed April 22, 2016, titled “Analyte meter including an RFID reader”, which are hereby incorporated by reference in their entireties. [00175] All references, including publications, patent applications and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. System Overview [00176] In accordance with new and unique aspects herein, methods and devices are described that utilize active electronics on an integrated circuit, such as an application specific integrated circuit (ASIC), within an implantable medical device (IMD), such as a pressure sensor. The integrated circuit is coupled, preferably directly, to a capacitive element, typically utilizing a capacitance to digital (C/D) converter circuit, to preferably digitize the capacitance measurement right at, or as practically close to, the capacitance source within the body. The preferred C/D converter circuit is configured to measure the capacitance of the 15694WOO1 (013-0615PCT1) 36 PATENT capacitive element and generate pressure data, preferably digital pressure data, based on the capacitance of the capacitive element. In some embodiments, the (digital) pressure data is indicative of the pressure in the lumen, in which the IMD is implanted. In other embodiments, the (digital) pressure data is indicative of the pressure elsewhere within the body, such as within another vessel or chamber, such as a chamber of the heart. The integrated circuit further includes at least one of a processor or circuit configured to modulate a return signal, to be transmitted by the coil, based on the (digital) pressure data. [00177] Prior to modulation into the return signal, at least one of a processor or circuit (within the integrated circuit) is further configured to: apply encoding to the (digital) pressure data to form encoded pressure data; and modulate the return signal, to be transmitted by the coil, based on the encoded pressure data. The encoding may, in an embodiment, include encryption applied to the digital pressure data. [00178] Embodiments utilize Near Field Communication (NFC) to both power the integrated circuit and any other active electronics and to retrieve the pressure data, preferably digitized pressure data. In accordance with new and unique aspects, performing the signal acquisition right at the capacitive element source mitigates the opportunity for noise and other environmental effects from corrupting an otherwise analog capacitive signal. In conventional approaches, an analog capacitive signal traveled from the capacitive element within analog components within the pressure sensor until applied, in an analog manner, to a return signal and transmitted to an external device located outside of the body or to another implantable device located in another location within the body. In an embodiment, a capacitive to digital converter is coupled to the capacitive element. Such a new and unique embodiment can result in a more accurate, consistent, and reliable measurement. 15694WOO1 (013-0615PCT1) 37 PATENT [00179] In an embodiment, once the signal is, preferably, digitized, the data quality is protected from noise and environmental conditions, maintaining the accuracy of the measurement. In accordance with new and unique aspects herein, some embodiments utilize an NFC communication protocol that is configured to operate and coexist in environments that are noisy and full of other interfering sources. In new and unique embodiments, NFC can be preferably utilized for communication within the complex medical system that includes the pressure sensor implanted within a patient’s body and the external device located outside the patient’s body. [00180] The integrated circuit includes memory configured to store various types of information, including calibration information, patient information, and a unique serial number assigned to the implantable sensor. This mitigates the need to manage the storage of the calibration information on an external device, such as within a memory stick, loaded within the external device, and the like. [00181] In some embodiments, the calibration information and all the digitized data can be encrypted via various cryptographic techniques such as, but not limited to, Advanced Encryption Standard (AES). In accordance with new and unique aspects, the ability to store unique identification information on an implantable medical device, such as the pressure sensor, enables the ability to use NFC to collect information from multiple pressure sensors and/or other implantable devices located in different locations within the body, facilitating correlation of different physiological data to improve patient care, treatment, diagnostics, and recommendations. [00182] There are multiple key advantages of the new and unique aspects described herein. Including, but not limited to, first, the measurement (e.g., blood pressure) is taken right at the source and, preferably, immediately digitized, encrypted, and sent out via digital communication protocols to mitigate effects of noise and other environmental conditions that could reduce the accuracy of the measurement. Second, NFC communication provides a means of telemetry and 15694WOO1 (013-0615PCT1) 38 PATENT powering, which is robust and easy to use. For example, it is easy for a patient, with the external device, to obtain a measurement that is, preferably, already digitized. Third, NFC is designed to operate and coexist in noisy environments with other interfering devices. Fourth, the use of NFC allows the simplification of the transmitter design with the use of standard off-the-shelf and proven components. Fifth, the use of NFC allows the potential for the device (e.g., IMD, pressure sensor) to be interfaced with patient devices, such as phones, further simplifying the ability of the patient to collect their data. Sixth, the storage of data within the implantable sensor, including calibration information and a unique serial number, mitigates the need to manage the storage of the calibration information on an external device. Additionally, in some embodiments, all the digital data can be encrypted and sent out through a protected channel to the receiver. [00183] In accordance with new and unique aspects herein, the methods and devices energize an IMD, such as but not limited to an implanted pressure sensor, and receive, preferably, digitized, encrypted data that represents the pressure proximate to the pressure sensor within the body. A technical advantage is realized as an accurate pressure is collected and, preferably, digitized at the source. The patient’s pressure, such as but not limited to pulmonary arterial pressure, is important both for accessing the immediate status of the patient, as well as to provide accurate data input that is used by other algorithms to assess the patient, treat the patient, modify treatment of the patient, provide a treatment notification, provide a treatment recommendation, select an appropriate therapy for the patient, reprogram a device, such as an implantable medical device, implantable sensor, implantable pressure sensor, external device, etc., and/or display information and/or recommendations related to the pressure and/or detected changes over time and status of the patient. [00184] In accordance with new and unique aspects herein, methods and devices are described that, in some embodiments, automatically and dynamically tune an external tunable matching network of an external coil (e.g., antenna, 15694WOO1 (013-0615PCT1) 39 PATENT inductive external coil), and monitor/adjust the power levels of the external coil communicatively connected to an external device, and/or automatically and dynamically tune an IMD tunable matching network of an IMD coil (e.g., antenna, inductive IMD coil) communicatively connected to an IMD to optimize the NFC link for the given configuration and environment. Additionally, or alternatively, methods and devices are described that automatically and dynamically tune the IMD tunable matching network of an IMD coil communicatively connected to an IMD receiving power from an external device to optimize the NFC link between the IMD and the external device. As changes in the patient’s body, positioning, external environment, etc., change, the matching can become detuned. The tuning can be done continuously, periodically, based on a trigger or measured/detected parameter, on-demand, etc., as the environment and form factor can be dynamic. Based on changes in proximity to the human body, form factor of the flexible/conformable external coil/antenna, breathing, movement, and changes to the dielectric properties of the tissue, one or more parameters of the system can be automatically adjusted to keep the coil(s) optimally tuned and the power output of the external coil set within an optimal range. This maximizes the performance of the system in the midst of the variability experienced during normal operation. [00185] In some embodiments, a matching network can be used to tune a coil (e.g., antenna) to its transceiver circuit. Typically, matching networks consist of capacitors, inductors, and resistors, and are static values. In accordance with new and unique aspects herein, the components of the matching networks of the external device and/or IMD discussed herein can, preferably, be dynamically and automatically adjusted to configure different matching network configurations. For example, the adjustment can be done by implementing a bank of components and switching them in and out with switches. In other cases, adjustable components can be used. Additionally, or alternatively, varactor(s) can be included in a matching network to change the capacitance with voltage (i.e., varying the voltage to vary the capacitance). Additionally, or alternatively, potentiometer(s) can be 15694WOO1 (013-0615PCT1) 40 PATENT included in a matching network to change the resistance of the matching network. It should be understood that a combination of these components can be used wherein one or more adjustable component and/or switch can be included within each matching network, and that other adjustable components not specifically identified may also be used. [00186] To control the configuration of the matching network(s) and ensure that it is maximizing the link performance, the receive signal strength indicator (RSSI) of the signal that’s received from the IMD can be, preferably, continuously and/or periodically monitored. In some cases, the coil/antenna matching components communicatively connected to the external coil and/or implanted coil can be adjusted/swept to determine the matching network configuration to set the associated coil at maximum signal point (e.g., maximum power transfer). In some cases, the entire range of frequencies can be evaluated during the adjustment/sweep of the components. In other cases, a sub-set of the entire range, a course sweep (larger steps), fine sweep (smaller steps), etc., can be evaluated. [00187] Another approach to control the adjustment of the matching network(s) and ensure that it is maximizing the link performance is to, in some embodiments, measure the reflection coefficient, which is the ratio of the reflected wave to the incident wave. Preferably, the coil (e.g., antenna) matching components communicatively connected to the external coil and/or implanted coil can be continuously and/or periodically adjusted/swept to determine the matching network configuration to set the associated coil to minimize the reflection coefficient at a target near field communication (NFC) frequency (e.g., 13.56 MHz). The entire range of frequencies can be evaluated during the adjustment/sweep of the components. In other cases, a sub-set of the entire range, a course sweep (larger steps), fine sweep (smaller steps), etc., can be evaluated. [00188] In other embodiments, the phase difference between the transmit and receive signals can be determined to control the adjustment of the matching network(s) and ensure that it is maximizing the link performance. Preferably, the 15694WOO1 (013-0615PCT1) 41 PATENT coil (e.g., antenna) matching components communicatively connected to the external coil and/or implanted coil can be continuously and/or periodically adjusted/swept to optimize the phase difference. The entire range of frequencies can be evaluated during the adjustment/sweep of the components. In other cases, a sub-set of the entire range, a course sweep (larger steps), fine sweep (smaller steps), etc., can be evaluated. [00189] In still further embodiments, power levels are monitored to ensure that the power remains within desired levels to maintain performance (e.g., powering the implanted system and achieving successful communication), to not waste power, and to prevent damage to sensitive components. Preferably, once the IMD and/or external tunable matching network(s) is tuned, such as within predetermined parameters or based on criteria, the RSSI values can then be determined continuously, periodically, on-demand, etc., and used to adjust the power if needed. For example, if the implant is shallow and close to the external coil and the power level is too high, the implant may need to shunt the excess power, resulting in undesirable heat and potentially negatively affecting the performance and also the patient’s safety and comfort. Thus, this power level can be dynamically adjusted based on the RSSI values to set the range of power that is necessary for the configuration of the system. [00190] According to new and unique embodiments herein, the preferable dynamic tuning of the matching network(s) of the coil(s)/antenna(s) provides improvements to the technical field of communicating bidirectionally and powering implantable medical devices. For example, the embodiments can provide technical improvements to one or both external devices and IMDs that communicate using NFC. Preferably, the embodiments provide the benefit of dynamically adjusting the matching networks of the coils to varying conditions. This can compensate for a less-than-ideal placement of the external device coil with respect to one or more IMD, as well as movement of the patient during the data collection session and external environmental factors. In some embodiments, further advantages are 15694WOO1 (013-0615PCT1) 42 PATENT realized as the dynamic tuning of the external and implanted coils, as well as the monitoring of the power levels of the system, can be accomplished while the IMD is measuring data, such as pressure data, and transmitting the IMD data to the external device. [00191] Figure 1A illustrates a system that includes an IMD 150 and an external device 104 implemented in accordance with embodiments herein. As discussed above, an IMD 150 may be an implantable pressure sensor or implantable sensor. An implantable pressure sensor may utilize active electronics on an integrated circuit, such as an application specific integrated circuit (ASIC). [00192] The IMD 150 is configured to be implanted within the body of a patient. The external device 104 is configured to be outside of the patient body. The external device 104 may be a reader, programmer, an external defibrillator, a workstation, a portable computer (e.g., laptop or tablet computer), a personal digital assistant, a cell phone (e.g., smartphone), a bedside monitor, include or be a sash, blanket, pillow, belt, garment, and the like. The external device 104 utilizes NFC to power the IMD 150 and to receive digitized data from the IMD 150. For example, the external device 104 may be coupled to an inductive antenna or coil and implement some or all of the functions and/or structure described in the patents and application cited herein, including but not limited to, US11759623B2, titled “Implantable medical devices including low frequency and high frequency clocks and related methods”, US11330981B2, titled “Method and apparatus for a burst operation pressure sensor”; US9792469B1, titled “Wireless physical property sensor with digital communications”; US11219379B2, titled “Wireless MEMS left atrial pressure sensor”; US8159348B2, titled “Communication system with antenna box amplifier”; US7492144B2, title ”Preventing false locks in a system that communicates with an implanted wireless sensor”; US7245117B1, titled “Communicating with implanted wireless sensor”; and US8237451B2, titled “Communicating with an implanted wireless sensor”, the complete subject matter for all of which are incorporated herein by reference in their entireties. 15694WOO1 (013-0615PCT1) 43 PATENT [00193] The IMD 150 may be implanted in a blood vessel, such as an artery or vein. In an embodiment, the IMD 150 is implanted within the pulmonary artery (PA) while in another embodiment, the IMD 150 or an additional IMD 150 (not shown) is implanted within the aortic artery. The IMD 150 may be anchored to the vessel wall of a blood vessel using one or more expandable loop wires. The diameter of each loop should be larger than the diameter of the target blood vessel in order to provide adequate anchoring force. Optionally, instead of the loop wire, the IMD 150 may be attached to the end of a self-expandable stent and deployed into the blood vessel through a minimally invasive method. This method may be preferable over the loop wire(s) in situations in which strong anchoring is needed. It should be understood that other anchoring mechanisms can be used. [00194] Alternatively, the IMD 150 may be secured to tissue surrounding the blood vessels. The IMD 150 may be secured in place by using a fixation screw (e.g., helix) attached to the housing. The screw may anchor the IMD 150 to patient heart tissue, such as shown in Figure 1B. The IMD 150 is configured to sense a physiologic parameter of interest (PPOI) and to generate signals indicative of the PPOI. In a non-limiting example, when the IMD 150 is disposed within the PA, the IMD 150 may sense, as the PPOI, blood pressure. [00195] The external device 104 is capable of energizing and communicating with multiple IMDs. For example, IMD 152 can also be a pressure sensor, which in this example is located within a chamber of the heart. Other IMDs capable of NFC communication are also contemplated, and can be implanted and/or affixed to a patient’s skin (e.g., partially implanted) in areas of the body other than those discussed and/or shown in Figures 1A-1C. For example, a glucose monitor, neurostimulator, body generated analyte test device, etc., can also communicate with the external device 104. In some embodiments, an IMD may have its own power, such as a battery, but communicate via an implantable coil with the external device 104 using NFC. 15694WOO1 (013-0615PCT1) 44 PATENT [00196] Figure 1B illustrates possible locations wherein one or more IMD 150, such as the implantable pressure sensor, may be implanted within the patient in accordance with embodiments herein. The one or more of IMDs 150 can be configured to collect blood pressure data at different locations within the patient. When more than one IMD 150 is implanted, the IMDs 150 may operate independently or in cooperation with one another. For example, as shown in Figure 1B, pressure data can be collected to measure i) pulmonary vascular resistance associated with the lungs, ii) pulmonary arterial pressure, iii) right atrial pressure, iv) right ventricular pressure, v) central venous pressure, vi) wedge pressure associated with the pulmonary vein, vii) left atrial pressure, viii) ejection fraction, ix) cardiac output, x) left ventricular pressure, xi) systemic blood pressure, and xii) systemic vascular resistance associated with systemic body tissues. It should be understood that other locations within the body are contemplated. The IMD 150 can be positioned, for example, within a lumen, a chamber of the heart, another organ, and the like. [00197] It should be understood that in other embodiments, the system of the IMD 150 and the external device 104 can include other implantable device(s), semi-implantable device(s) (e.g., devices attached to and extending into the skin of the patient such as a continuous glucose monitor), and external devices (e.g., wearables). These devices can communicate information to the external device 104 that can be correlated in time with the data received by the external device 104 over NFC from the IMD150. [00198] For example, Figure 1C illustrates an embodiment, in which an IMD 150, such as the implantable pressure sensor, and a second IMD 100, such as an implantable cardiac monitor, are implanted within a patient in accordance with embodiments herein. It is understood that the IMD 100 may represent various other types of implantable medical devices, such as a pacemaker, cardioverter- defibrillator, leadless pacemaker, neurostimulator and the like. In the embodiment of Figure 1C, the IMD 150 may communicate with one or both of the external 15694WOO1 (013-0615PCT1) 45 PATENT device 154 and IMD 100. For example, the IMD 150 may communicate with the IMD 100 using conducted telemetry. For example, the IMD 150 may communicate with an IMD 100 that delivers therapy such as described in US application serial no.63/596,402, filed November 6, 2023, titled “System and Method for Diastolic- Enhanced Systolic Peak Detection” which is hereby incorporated by reference in its entirety. Additionally, the IMD 100 may communicate directly with the external device 154. [00199] The IMD 100 is intended for subcutaneous implantation at a site near the heart. The IMD 100 includes a pair of spaced-apart sense electrodes 114, 126 positioned with respect to a housing 102. The sense electrodes 114, 126 provide for detection of far field electrogram signals. In one example, far field CA signals for a series of beats are obtained. Numerous configurations of electrode arrangements are possible. For example, the electrode 114 may be located on a distal end of the IMD 100, while the electrode 126 is located on a proximal side of the IMD 100. Additionally, or alternatively, electrodes 126 may be located on opposite sides of the IMD 100, opposite ends or elsewhere. The distal electrode 114 may be formed as part of the housing 102, for example, by coating all but a portion of the housing with a nonconductive material such that the uncoated portion forms the electrode 114. In this case, the electrode 126 may be electrically isolated from the housing electrode 114 by placing it on a component separate from the housing 102, such as the header 120. Optionally, the header 120 may be formed as an integral portion of the housing 102. The header 120 includes an antenna 128 and the electrode 126. The antenna 128 is configured to wirelessly communicate with the external device 154 and/or IMD 150 in accordance with one or more predetermined wireless protocols (e.g., Bluetooth, Bluetooth low energy, Wi-Fi, etc.). Powering and Receiving Data Via NFC 15694WOO1 (013-0615PCT1) 46 PATENT [00200] Figure 2A illustrates a system 200 wherein the external device 104 uses NFC to power and receive data from the IMD 150 in accordance with embodiments herein. The system 200 shows some of the components of the IMD 150 and the external device 104. In some embodiments, data acquired by the IMD 150 for heart failure applications includes, for instance, measuring right-side preload and afterload as well as left-side preload and afterload. The right and left side preload and afterload may be derived from surrogates. For example, the right atrial pressure may be utilized as an estimate of the right ventricular EDP. Cardiac filling pressures may be used as surrogates for estimating cardiac chamber volumes. Left ventricular end diastolic volume (LVEDV) corresponds to myocardial fiber length at the end of left ventricular filling and thus preload for the left ventricle (LV). Surrogate markers such as central venous pressure (CVP), right atrial pressure (RAP), pulmonary artery occlusion pressure (PAOP), pulmonary artery diastolic pressure (PADP), and left atrial pressure (LAP) may be used to estimate left ventricular end diastolic pressure (LVEDP), for which correlation with LVEDV is assumed. [00201] It should be understood that the functionality of the IMD 150 as described herein can be included within other implantable medical devices. Non- limiting examples of other implantable medical devices are discussed above and include, but are not limited to, cardiac monitoring devices, pacemakers, implantable leadless monitoring and/or therapy devices, subcutaneous cardioverter defibrillators, cardioverters, cardiac rhythm management devices, defibrillators, neurostimulators, left atrial or pulmonary artery pressure sensors, blood glucose monitoring devices, etc. [00202] The IMD 150 includes an inductive IMD coil 202 (e.g., IMD antenna) for communications and power transfer, an integrated circuit 204 (e.g., ASIC), and a Micro-Electromechanical Systems (MEMS) capacitive element 206 for use as a pressure transducer. The MEMS capacitive element 206 is also referred to herein as a capacitive sensor. The capacitive element is a non-inductive capacitive 15694WOO1 (013-0615PCT1) 47 PATENT element or non-L capacitive element. The terms ASIC and integrated circuit can be used herein interchangeably. The inductive IMD coil 202 is coupled to the integrated circuit 204 and the integrated circuit 204 is coupled to the MEMS capacitive element 206 as discussed further herein. The integrated circuit 204 further includes an IMD NFC transceiver 208 (e.g., capable of receiving and/or transmitting NFC), memory 210, and typically, a capacitance to digital (C/D) converter 212. The capacitance of the MEMS capacitive element 206 will vary as a function of the environmental pressure. In other words, the capacitive element 206 has a capacitance configured to vary in response to changes in pressure. The integrated circuit 204 interfaces with the MEMS capacitive element 206, such as via the C/D converter 212, to measure the capacitance values. [00203] The memory 210 is a tangible and non-transitory computer-readable storage medium. In some embodiments, logic is hard coded, such as by using digital transistors, on the integrated circuit 204 to perform the operations of the IMD 150. In some embodiments, the memory 210 can be a non-volatile memory (NVM). If the power is removed, the memory 210 will retain its state, and the memory 210 can be re-written and changed. The memory 210 stores program instructions (e.g., software) that are executed by one or more processors of the integrated circuit 204 to perform the operations of the IMD 150 described herein. Additionally, or alternatively, the memory 210 stores information, such as physiologic data generated by the MEMS capacitive element 206, information generated by the C/D converter 212, calibration information, serial number, etc. In some embodiments, the memory 210 may store the physiologic data and/or the information of the C/D converter 212 until it is transmitted to the IMD 100 and/or the external device 104. [00204] In some cases, the external device 104 can be configured to direct the integrated circuit 204 to store information in the memory 210. For example, during an implant procedure the external device 104 may direct the integrated circuit 204 to store calibration information, baseline information, and the like. The external device 104 can also be used to store new and/or updated calibration 15694WOO1 (013-0615PCT1) 48 PATENT and/or baseline information at a later date, such as during another procedure or during an office visit. In other embodiments, an external device 104 may be designed for the patient to be used at home and may not have the capability to direct the integrated circuit 204 to write to the memory 210. Instead, a home-use external device 104 may be limited with respect to interactions with the IMD 150 to providing NFC and receiving communications. [00205] To optimize the system and NFC link, an inductive external coil 231 (e.g., external antenna) communicatively connected to the external device 104 may be designed with a size to generate a larger field, such as to ensure communication of up to six inches deep within the patient’s body. External coil dimensions of at least 4” to 12” (e.g., 10.16 cm to 30.48 cm) in radius may be used. In some embodiments, the inductive external coil 231 can either be embedded in a pillow or blanket to be positioned underneath or on top of the patient, or embedded in other concepts like a sash or belt. In some cases, the inductive external coil 231 may be connected to but housed separate from other components of the external device. [00206] The IMD 150 includes a housing 214 that holds and encapsulates the inductive IMD coil 202, integrated circuit 204, and MEMS capacitive element 206 to protect these components from the harsh organic environment of the body. The housing 214 may be hermetically sealed. [00207] Figure 2B illustrates an example of the MEMS capacitive element 206 formed in accordance with embodiments herein. The element 206 includes at least one lower electrode 207, 209 (e.g., lower electrode) formed on pedestal 416 and an electrode 211 (e.g., upper electrode) formed on an inner surface of glass 412. The pedestal 416 and glass 412 are discussed further below. An air gap 213 separates the electrode 207, 209 and the electrode 211. In some embodiments, the electrode 207, 209, 211 are each a metallized layer. [00208] It should be understood that the below description of the MEMS capacitive element 206 is an example and represents only one implantable sensor 15694WOO1 (013-0615PCT1) 49 PATENT that may be used together with the new and unique aspects discussed herein. Additionally, or alternatively, other implantable sensors having a pressure- dependent circuit can be used. Examples of MEMS capacitive element 206 can be found in at least US published application number 2022/0079456, filed October 21, 2021, titled “System and method for calculating a lumen pressure utilizing sensor calibration parameters”; US patent 9,792,469, filed October 17, 2016, titled “Wireless Physical Property Sensor with Digital Communications”; and US patent 9,653,926, filed May 21, 2015, titled “Physical Property Sensor with Active Electronic Circuit and Wireless Power and Data Transmission”, which are hereby incorporated by reference in their entireties. [00209] The capacitor in the MEMS capacitive element 206 consists of at least two conductive elements (e.g., electrodes 207, 209 and electrode 211) separated by the gap 213. If a force is exerted on the IMD 150, a portion of the IMD 150 deflects, such as the glass 412, changing the relative position between the at least two conductive elements. This movement will have the effect of reducing the gap 213 between the conductive elements, which will consequently change the measured capacitance. Changes in pressure alter the capacitance and, ultimately, cause a shift in the resonant frequency of the IMD 150. The pressure of the environment external to the IMD 150 is then determined by referencing the value obtained for the resonant frequency to a previously generated curve relating resonant frequency to pressure. Integrated Circuit [00210] Figure 3A illustrates a block diagram of a preferable integrated circuit 204 in accordance with embodiments herein. The preferred integrated circuit 204 includes two main building blocks, preferably the C/D converter 212 and preferably an NFC block 216. Preferably, additional blocks include temperature measurement, typically utilizing a temperature sensor 218, preferably the memory 210 (e.g., one-time-programmable (OTP) memory, non-volatile memory (NVM)), 15694WOO1 (013-0615PCT1) 50 PATENT preferably power regulation block 220, and preferably resonant capacitor and tuning trim 222. [00211] The NFC block 216 is interconnected to the inductive coil 202 via connections 228, 230. The NFC block 216 preferably includes power harvesting 248 to collect energy from the transmitted NFC and provide power to the power regulation block 220 via connection 232, which in turn can power the memory 210 via connection 234, the C/D converter 212 via connection 236, and temperature sensor 218 via connection 237. In some embodiments, hard coded logic (e.g., circuit, circuitry) of the integrated circuit 204 can accomplish requests, receive data, output data via NFC, etc. In other embodiments, the NFC block 216 includes and/or is in communication with one or more preferred processor 246 incorporated within the integrated circuit 204 that is configured to accomplish requests, receive data, output data via NFC, and the like. [00212] The power regulation block 220 takes the power from the NFC power harvesting 248 and generates stable voltages and currents to power the integrated circuit 204. The NFC field will not be a constant value, varying due to a plurality of environmental factors including the distance between the external device 104 and the IMD 150. The power regulation block 220 provides a stable voltage and current to the integrated circuit 204 in order to perform consistently and take accurate measurements. [00213] In some embodiments, the power regulation block 220 can preferably include OTP/NVM read/write functionality 221. Writing to memory 210 takes a lot of power and needs accurate power regulation. In some cases, the power regulation may need to boost up the voltage in order to write to the memory 210 effectively. The OTP/NVM read/write functionality 221 captures the aspects of power regulation that are needed to write to the memory 210. [00214] The power regulation block 220 controls when the applicable blocks are powered. In some embodiments, the C/D converter 212 will always be powered when power is available. In other embodiments, the memory 210 will only be 15694WOO1 (013-0615PCT1) 51 PATENT powered in specific times when a write to memory instruction or read from memory instruction is received. [00215] The optional temperature sensor 218 receives a temperature request 224 from the NFC block 216 and sends back temperature data 226. The temperature sensor 218 measures the immediate temperature, such as of the integrated circuit 204. For example, as the integrated circuit 204 is powered by NFC, the temperature can increase. Monitoring the temperature over a time period (e.g., 18 seconds, 30 seconds) that the integrated circuit 204 is expected to be powered during normal use can allow adjustments in the calibration, capacitance trimming, etc., to be made prior to implant. In other embodiments, the temperature sensor 218 can be used to measure and track core body temperature. [00216] The memory 210 preferably stores a unique identifier (UID) 242 or other identifier(s) (e.g., unique sensor identifier, unique serial number) assigned to the IMD 150. The memory 210 preferably also stores calibration information 244 (e.g., coefficients) that can be determined during manufacturing, once the IMD 150 is assembled, upon implant within a patient, and/or updated after being implanted within a patient for a period of time. By way of example, calibration information 244 is a set of coefficients that represent how the specific MEMS capacitive element 206 performs, and can include, for example, coefficient values and offsets due to temperature and dielectric effect. The memory 210 preferably stores baseline information 258 that is acquired and stored during the implant procedure. In some embodiments, the external device 104 can direct the integrated circuit 204 to store the baseline information during the implant procedure. The memory 210 may also store a patient identifier, such as a patient ID within a medical network, a social security number, and the like. [00217] The memory 210 receives an information request 238 from the NFC block 216 and sends back the requested information 240, such as the UID 242, the calibration information 244, and/or baseline information 258. Optionally, the memory 210 may store the pressure data 256 once digitized by the C/D converter 15694WOO1 (013-0615PCT1) 52 PATENT 212. The pressure data may be stored in a buffer (e.g., a first in first out buffer) or other type of memory before transmission to the external device 104. [00218] By way of example, calibration information 244 is a set of coefficients that represent how the specific MEMS capacitive element 206 performs. In manufacturing, the pressure is varied and how the frequency (the frequency corresponds to capacitance) changes is measured. In some embodiments, the relationship between the two is modeled with a second order polynomial fit. That second order polynomial has three coefficients that are determined during manufacturing. The coefficients are written into the memory 210 as the calibration information 244 of the integrated circuit 204 during manufacturing. Calibration is discussed further below in Figure 5. [00219] Baselining is accomplished during and after implantation of the IMD 150. During the implant procedure, the physician will also feed in a pressure measuring catheter. The pressure that the pressure measuring catheter measures is then compared with the pressure measured by the IMD 150, and any differences are “baselined”. In some embodiments, the value the IMD 150 provides is baselined to the pressure measured by the pressure measuring catheter. Baselining is discussed further below in Figure 6. The one or more processors 246 or other circuitry of the integrated circuit 204 can accomplish fault detection within the integrated circuit 204 and MEMS capacitive element 206. Faults that can be detected include, but are not limited to, capacitance to digital conversion including built in self test (e.g., BIST), within the memory 210, within processing, and shunts and/or opens associated with (e.g., within and/or connected to) the MEMS capacitive element 206. Additionally, the integrated circuit 204 can detect an anomalous reading (e.g., due to EMC, noise). For example, a current reading (or spike) by the MEMS capacitive element 206 that is greater than 10fF (approximately 4 mmHg) from the expected value or reading can be treated as anomalous. In some cases, the expected reading can be a previous reading or the most recent reading, while in other cases the expected reading can be based on 15694WOO1 (013-0615PCT1) 53 PATENT an average of previous readings, such as the average of a number of the previous readings (e.g., 10, 20, 30 readings). [00220] The integrated circuit 204 will send a fault bit along with each measurement. The fault bit will be enabled if there is a detection of a fault or anomalous reading. [00221] In some embodiments, the BIST can be accomplished using a capacitor (not shown) internal to the C/D converter 212. The BIST may be accomplished i) every time a measurement is taken (e.g., approximately 100 times a second), ii) every measurement session (e.g., approximately once a day), or iii) on demand (determined by the integrated circuit 204 or the external device 104). [00222] The one or more processors 246 or other circuitry of the integrated circuit 204 provide the ability to trim the resonant capacitor to optimize it for the NFC frequency. For example, the resonant capacitor resonates with the inductive IMD coil 202; however, manufacturing and assembly variability may result in frequency variations. It is desirable to trim the resonant capacitor so that it resonates at the NFC frequency of 13.56 MHz. For example, the NFC block 216 can have an on-chip resonant capacitor as well as the ability to trim the capacitor (shown collectively as resonant capacitor and tuning trim 222). In some embodiments, an array of capacitors can be wired in or out of circuit via trim bits. The trim bits can be programmable via the NFC interface and powering, ideally when the IMD 150 is fully packaged. For example, the telemetry controls the trimming (e.g., tells which trim bits to enable/disable) and the NFC powering provides the power needed to write into the memory 210. [00223] The one or more processors 246 or other circuitry of the integrated circuit 204 further provide the ability to store implant baseline information in the memory 210, such as during an implant procedure or other procedure. [00224] Upon receiving power via the NFC coil 202, the NFC block 216 can “wake up” and send a measurement request 254 to the C/D converter 212. The C/D converter 212, powered by the power regulation block 220, converts the 15694WOO1 (013-0615PCT1) 54 PATENT capacitance into a digital word that represents the pressure within the area around the MEMS capacitive element 206 at the particular point in time. There are numerous methods to measure capacitance including a step response, relaxation oscillator, voltage divider, and bridge configuration. In one example, a modified version of the relaxation oscillator consists of current sources to charge and discharge the MEMS capacitive element 206, a feedback loop to form an oscillator (denoted first oscillator herein), and then a second oscillator used to measure the time of the charge and discharge cycles, which corresponds to the MEMS capacitor value. This modified version of the relaxation oscillator can be implemented without the use of external components and since both oscillators are implemented on the same silicon die on the integrated circuit 204, the effects of process, aging, and environmental conditions, are mitigated as they would affect both oscillators at the same time. [00225] Figure 3B illustrates an exemplary C/D converter 212 implemented as a modified version of the relaxation oscillator in accordance with embodiments herein. The C/D converter 212 measures capacitance directly. In some embodiments, a constant current source is used, the MEMS capacitive element 206 is charged up, and the charging time is measured. [00226] At the start of the measurement, current source 260 turns on and digital counter 262 starts to count. The current source 260 charges up the MEMS capacitive element 206 at node A 264. Once the voltage at node A 264 exceeds a reference voltage 266, comparator 268 will trip and set node B 270 to high (previously it was low). This stops the digital counter 262, which then holds a digital number that correlates to the charge up time. [00227] The voltage at node B 270 is used to control a discharge switch 272 which discharges the MEMS capacitive element 206 at Node A 264. After the measurement is recorded at recording block 274 (or sent out via NFC 275) and after a small delay time until the MEMS capacitive element 206 is discharged, the 15694WOO1 (013-0615PCT1) 55 PATENT system is reset, the node B 270 is pulled back down to low, and then, another measurement sequence can start. [00228] Figure 3C illustrates an implementation of the C/D converter 212 with transistors in accordance with embodiments herein. In complementary metal-oxide semiconductor (CMOS) technologies, current source 280 can be implemented with a P-type metal-oxide semiconductor (PMOS) transistor and discharge switch 282 can be implemented with an N-type metal oxide semiconductor (NMOS). The digital counter 262 can also be timed with a ring oscillator 28 serving as its clock. When implemented on a single chip ASIC (i.e., integrated circuit 204), the PMOS and NMOS transistors in the ring oscillator 284 can be optimally matched on the layout, using common centroiding and symmetry techniques, to the MP1 and MN1 transistors (current source 280 and discharge switch 282, respectively). Thus, any variations due to process, temperature, voltage, and other environmental conditions will impact all the transistors equally and thus cancel out. For example, if a condition causes the PMOS transistors to be stronger and produce more current, then MP1 will have a higher current that will speed up the charging time on the MEMS capacitive element 206. However, the PMOS transistors in the ring oscillator 284 will also have a higher current, and thus the oscillator 284 will speed up, and thus the digital counter 262 will count faster. These two effects will cancel out such that the digital counter 262 will still produce the same counts for the MEMS capacitive element 206 charging time even if the PMOS transistors’ current varies. [00229] The C/D converter 212 sends pressure data 256 to the NFC block 216. Preferably, the one or more processors 246 or other circuitry of the integrated circuit 204 can encrypt the pressure data, serial number, temperature, etc., prior to transmitting the data to the external device 104. Preferably, for example, encryption 250 may use the Advanced Encryption Standard (AES) data encryption capability (128-bits block), although is not so limited and other encryption schemes/standards can be used. 15694WOO1 (013-0615PCT1) 56 PATENT [00230] For example, the calibration and serial number information can be encrypted and read by the external device 104 when required. Additionally, since the IMD 150 (e.g., integrated circuit 204) will contain unique identifiers programmed into the integrated circuit 204, multiple IMDs 150 placed in various locations to capture more than a single hemodynamic parameter will be capable of being interrogated and measured. For example, the IMD 150 shown in Figure 1A, implanted within the pulmonary artery, and the IMD 152, located within a chamber of the heart, can be interrogated simultaneously, as the external device 104 can distinguish the source of the data based on unique identifier(s). Near Field Communication [00231] Once the pressure measurement is captured and converted into a digital word (e.g., digitized) by the C/D converter 212, the pressure data is sent to the NFC block 216 for encoding (e.g., adding information such as error bit) to form encoded pressure data. Optionally, the encoded pressure data may further be encrypted (e.g., encryption 250). The encoded and/or encrypted pressure data is then utilized to modulate the return signal. [00232] NFC Type 5, which was released in 2015, is based on Radio Frequency Identification (RFID) technology defined by ISO/IEC 15693, operates at 13.56 MHz, and enables a longer range, up to 1.5 meters, than what was previously achievable (e.g., typically 10 cm or less). This new standard makes it possible to achieve reasonable communication distances that would be required for deep implants (e.g., pressure sensors implanted in the pulmonary artery) such as for implantable heart failure applications, which may experience up to six inches of distance between the transmitter (e.g., external device 104) and the IMD 150 and overcome the challenges of the human body tissue between the transmitter and IMD 150. To achieve the desired range under the implanted conditions, coil sizes are determined as further discussed herein. According to new and unique aspects, with the small size of the IMD coil 202 and very large distance of 15694WOO1 (013-0615PCT1) 57 PATENT operation, around 6 inches, NFC is a very non-obvious choice for telemetry because NFC is generally targeted for larger coils and very short distances. [00233] Some examples of NFC devices operate at 13.56 Megahertz (MHz). The following is a non-exhaustive list of examples of NFC protocols: ECMA-340, ECMA-352, ISO/IEC 14443, ISO/IEC 15693, ISO/IEC 18000-3, ISO/IEC 18092, and ISO/IEC 21481, all of which are incorporated by reference herein in their entirety and for all purposes. Examples also include RFID protocols, also incorporated by reference herein in their entireties and for all purposes. [00234] NFC Type 5 can use a Manchester encoding modulation scheme along with load modulation. The main principle behind Manchester code is encoding 1s and 0s as a part of transitions, not static values. For example, instead of a 1 and 0 being encoded as a high and low (e.g., high and low voltage levels, first and second states), they are encoded as the transition from high (e.g., a first state) to low (e.g., a second state) and vice versa. This modulation scheme mitigates the issue of loss of clock synchronization as every bit has a transition. This scheme also prevents situations where long strings of 1s and 0s lead to a growing DC offset, which can degrade the RF link quality. The load modulation scheme simply switches in and out loads to represent signal transitions that can be read on the external transmitter side. This allows for a very low-power telemetry from the implant side (e.g., preferably NFC telemetry 252). These advantages of clock synchronization, improved RF link quality, and low-power telemetry are important for simplifying the design of the miniature deep implant and maximizing the signal quality. [00235] In some embodiments, the at least one processor or circuit can modulate the return NFC signal utilizing load modulation to transition an impedance of the inductive IMD coil 202 between first and second states. In some cases, the at least one processor or circuit can vary or change the impedance of the inductive IMD coil 202 (e.g., load impedance) to change the power level or strength of the signal corresponding to data values in the encoded pressure data. 15694WOO1 (013-0615PCT1) 58 PATENT In further embodiments, the transition of the impedance (e.g., load impedance, impedance of the inductive IMD coil 202) from the first state to the second state corresponds to a logical one in the encoded pressure data and the transition of the impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data. [00236] In some embodiments, serial encoding can be applied to the digital pressure data. For example, in some embodiments, at least one of a processor or circuit is configured to serially encode the digital pressure data by applying serial encoding. The serial encoding can be Non-Return-to-Zero (NRZ) encoding, Non- Return-to-Zero-Inverted (NRZI) encoding, Return-to-Zero (RZ) encoding, or Manchester encoding. [00237] In some embodiments, the IMD 150 comprises the coil 202 configured to receive NFC signals from the external device 104 and to transmit return NFC signals to the external device 104. The IMD 150 includes the capacitive element 206 having a capacitance configured to vary in response to changes in pressure, and an integrated circuit 204 coupled to the capacitive element 206. The integrated circuit 204 includes at least one of a processor or circuit configured to generate pressure data based on the capacitance of the capacitive element 206. In some embodiments, optionally the pressure data is encoded to form encoded pressure data, and the return NFC signal, to be transmitted by the coil 202, is modulated based on the encoded pressure data. [00238] In other embodiments, the IMD 150 comprises the coil 202 configured to receive NFC signals from the external device 104 and to transmit return NFC signals to the external device 104. The IMD 150 includes a capacitive element 206 having a capacitance configured to vary in response to changes in pressure, and the integrated circuit 204 coupled to the capacitive element 206. The integrated circuit 204 can optionally, in some embodiments, include the C/D converter 212 configured to measure the capacitance of the capacitive element 206 and generate digital pressure data based on the capacitance of the capacitive 15694WOO1 (013-0615PCT1) 59 PATENT element 206. Optionally, the integrated circuit 204 can further include at least one of a processor or circuit configured to modulate the return NFC signal, to be transmitted by the coil 202, based on the digital pressure data. Calibration Information [00239] The integrated circuit 204 can store information including, but not limited to, calibration information 244, baseline information 258, patient information and a UID 242. The calibration information 244 (e.g., coefficient values and offsets due to temperature and dielectric effect) is specific to the MEMS capacitive element 206 and can be obtained and programed into the IMD 150 during manufacturing. This calibration and serial number information can be encrypted and read by the external device 104 when required. Additionally, since the IMD 150 (e.g., integrated circuit 204) will contain unique identifiers programmed into the integrated circuit 204, multiple sensors/IMDs 150 placed in various locations to capture more than a single hemodynamic parameter will be capable of being interrogated and measured. For example, the IMD 150 shown in Figure 1A, implanted within the pulmonary artery, and a sensor (not shown) in Figure 1B, implanted within the aorta, can be interrogated simultaneously, as the external device 104 can distinguish the source of the data based on unique identifier(s). An exemplary method for calibrating the pressure sensor is discussed in Figure 5. Pressure Sensor Packaging [00240] Figures 4A–4K show embodiments illustrating the positioning of the integrated circuit 204 within the IMD 150 as well as how the integrated circuit 204 can be connected within the assembly. Although not explicitly shown in all the figures, when the IMD 150 is fully assembled, the MEMS capacitive element 206 and the inductive IMD coil 202 are connected directly to the integrated circuit 204 or a printed circuit board (PCB), to which the integrated circuit 204 is interconnected. 15694WOO1 (013-0615PCT1) 60 PATENT [00241] It should be understood that the directional indicators of “proximal” and “distal” used with some of the figures are for description purposes only. Proximal and distal are not limiting to an orientation in which the IMD 150 may be implanted or assembled. [00242] Figure 4A shows a top view of the IMD 150 (e.g., implantable pressure sensor) that includes the integrated circuit 204 that is communicates with and is preferably powered by the external device 104 using NFC in accordance with embodiments herein. In some cases, the overall size of the IMD 150 is limited to being able to be delivered via a 12F-14F catheter. The IMD 150 includes inductive IMD coil 402 (also referred to as inductive NFC coil and inductive IMD coil 202 herein), the integrated circuit 204, and the MEMS capacitive element 206 (the electrode 211 is shown). Coil terminations 404, 406 interconnect, such as via wire bond, the inductive IMD coil 402 and the integrated circuit 204. One end of capacitor traces 408, 410 are interconnected with, via wire bond, the integrated circuit 204, and to the electrodes 207, 209 (not shown) located at the other end of the capacitor traces 408, 410. A top glass 412 extends over the housing and the components, and the assembly is hermetically sealed. [00243] Holes 413a, 413b, 413c, 413d, extend through the glass 412 and the body of the IMD 150. In some embodiments, fastening element(s) (not shown) such as anchor loops can utilize one or more of the holes 413 to removably fasten the IMD 150 to the delivery catheter. It should be understood that other mechanisms may be used to removably fasten the IMD 150 to the delivery catheter and/or securely position the IMD 150 within a vessel. [00244] Figure 4B shows an exploded view of the IMD 150 (e.g., implantable pressure sensor) in accordance with embodiments herein. The top glass 412, inductive IMD coil 402, integrated circuit 204, and sensor body 414 are shown. The sensor body 414 includes a pedestal 416 attached to an inner floor of a bottom 418 of the sensor body 414 that extends toward a top 420 of the sensor body 414. In other embodiments, the pedestal 416 and sensor body 414 are formed of a 15694WOO1 (013-0615PCT1) 61 PATENT single piece of material. The pedestal 416 remains in a fixed relationship with the sensor body 414 and is not expected to move. [00245] A cavity 422 is formed between outer side surfaces 428 of the pedestal 416 and inner side surfaces 430 of the sensor body 414. The cavity 422 accommodates the inductive IMD coil 402 between the outer side surfaces 428 of the pedestal 416 and the inner side surfaces 430 of the sensor body 414. According to new and unique aspects herein, the cavity 422 is designed to fit in a sufficiently large inductive coil, the inductive IMD coil 402, with sufficient turns and wire gauge width to maximize the link for NFC communication up to six inches. The cavity 422 supports the telemetry inductor and allows room for the integrated circuit 204, while minimizing any potential impact to construction of the IMD 150 and sensor drift. For example, the materials forming the sensor body 414 and glass 412, as well as the processes of joining and sealing the components, are known to mitigate sensor drift. [00246] A distal end 432 of the pedestal 416 is rounded and extends toward a distal end 424 of the sensor body 414. A proximal end 434 of the pedestal 416 extends toward a proximal end 426 of the sensor body 414 and is squared-off or forms a mostly flat vertical surface having a width 460 between beveled edges of the pedestal 416 that are proximate the outer side surface 428. The pedestal 416 has a height 462 extending from a top surface of the pedestal 416 the floor of the cavity 422, a maximum width 463, and a maximum length 465. The portion of the cavity 422 formed proximate the proximal end 426 is sized to accommodate the integrated circuit 204 between the proximal end 434 of the pedestal 416 and the coil 402. [00247] The inductive IMD coil 402 can have a length 436 selected within an interval of from 2 mm to 20 mm, a width 438 selected within an interval of from 1 mm to 4 mm, and a height 440 selected within an interval of from 0.5 mm to 2 mm. Alternatively, in some embodiments the coil 402 can have a maximum length 436 of 10 mm, a maximum width 438 of 2 mm, and a maximum height 440 of 1 mm. In 15694WOO1 (013-0615PCT1) 62 PATENT still further embodiments, as shown in Figure 4K, the inductive IMD coil 402 can have a length 436 of approximately 9.75mm, a width 438 of approximately 2.5 mm, and a height 440 of approximately 1.1mm. The measurements of length 436, width 438, and height 440 are exemplary and not limited. Also, in some cases the length 436, width 438, and height 440 of the coil 402 fit within the length, width, and height of the cavity 422 without extending beyond a top surface of the pedestal 416 or sensor body 414. [00248] In some embodiments, based on the constraints of a very small IMD 150 and large communication distance (e.g., up to six inches), the number of turns of the inductive IMD coil 402 are maximized within the constraints of the packaging while also providing sufficient wire gauge to mitigate high resistance within the wires. For example, the inductive IMD coil 402 can have 20–50 turns with a 48–36 gauge wire. [00249] In some embodiments, the inductive IMD coil 402 can be a multilayer coil made from, for example, copper or gold wires insulated with polymeric coatings. Laser stripping can be used to remove the insulation from the wires to form the coil terminals 404, 406, and the coil terminals 404, 406 will be bonded to the ASIC chip gold electrode pads. [00250] The long-term stability (e.g., not drifting over time) of the IMD 150 is preferably considered when choosing materials. Selecting suitable materials for use in the IMD 150 involves multiple considerations, such as the unique properties of each material, their behavior under processing conditions, and their performance in the final application. For example, the material stability, mechanical stability, and bonding integrity (e.g., inductive IMD coil 402 to the chip pads or integrated circuit 204 to the fused silica) present challenging requirements, as both the adhesive(s) and inductive IMD coil 402 in the long term will impact the device drift behavior. Additionally, maintaining the vacuum inside the IMD 150 after processing will lead to better functional performance of the device. 15694WOO1 (013-0615PCT1) 63 PATENT [00251] Turning first to the inductive IMD coil 402, a non-limiting list of considerations comparing copper vs. gold properties is provided: [00252] (1) Electrical Conductivity: Copper has excellent electrical conductivity, making it ideal for efficient electrical signal transmission in coils. While not as conductive as copper, gold still offers very good electrical conductivity. [00253] (2) Corrosion and Oxidation Resistance: Gold is highly resistant to oxidation and corrosion, making it ideal for long-term stability. Copper is prone to oxidation, forming a surface layer of copper oxide when exposed to air, especially at high temperatures, which can affect its conductivity and bonding capabilities. [00254] (3) Mechanical Strength: Copper has good tensile strength (better than gold), which is an advantage in fabricating and handling the coils. [00255] (4) Thermal Stability: Gold has excellent thermal stability, maintaining its properties over a wide temperature range (coils will be exposed to more than 300C in manufacturing processes). [00256] (5) Cost-Effectiveness: Compared to gold, copper is much cheaper. Gold is significantly more expensive than copper. [00257] (6) Wedge Bonding to Gold Electrode Pads: Gold wires are more compatible with gold pads in terms of bonding, while copper wires are less reliable due to intermetallic compound formation in bonding to gold pads. Copper-to-gold bonding has a very narrow window for processing parameters compared to gold- to-gold bonding. [00258] (7) Laser Stripping Compatibility: Gold is stable and resistant to oxidation in exposure to laser processing. Copper can get oxidized in laser stripping and requires a special processing environment to prevent oxidation. [00259] Turning to adhesive selection for bonding the silicon integrated circuit 204 to the fused silica cavity (e.g., the pedestal 416), following is a nonlimiting list of considerations: [00260] (1) Low Outgassing: To maintain vacuum integrity. Outgassing overtime will impact long-stability performance. 15694WOO1 (013-0615PCT1) 64 PATENT [00261] (2) High-Temperature Resistance: The adhesive should have high thermal stability to withstand processing and operating temperatures (up to 300°C). [00262] (3) Thermal Compatibility: The adhesive should have a Coefficient of Thermal Expansion (CTE) close to that of silicon and fused silica to minimize thermal stress. [00263] (4) Mechanical Properties: Adequate tensile and shear strengths to maintain bond integrity, especially after processing. [00264] (5) Curing Process Compatibility: The curing process should align with the IMD’s 150 manufacturing processes without necessitating extensive modifications to the existing processes. [00265] (6) Manufacturing and Application Ease: Preference for adhesives that are simple to apply, possibly with automated dispensing systems, to ensure consistency and efficiency in manufacturing. [00266] A list of adhesives that may be considered for use within the IMD 150 include, but are not limited to, i) UV-Curing Epoxy Adhesive: Master Bond UV25, ii) Epoxy Adhesive: Master Bond Supreme 17HT, iii) Epoxy Adhesive: Master Bond Supreme 121AO, iv) Silicone Adhesive: NuSil-CV1-1142, v) Silicone Adhesive: NuSil MED3-4213, vi) Polyimide: PI 2611, and vii) Epoxy Adhesive: Master Bond Supreme 3HTND-2DA. [00267] Turning to the integrated circuit 204, the integrated circuit has a length 442, width 444, and height 446 allowing the integrated circuit to fit within the cavity 422. [00268] Figures 4C and 4D show isometric views of the IMD 150 (e.g., implantable pressure sensor) without and with the top glass 412 shown, respectively, in accordance with embodiments herein. As discussed with respect to Figure 4A, the coil terminations 404, 406 of the inductive IMD coil 402 are interconnected via wire bond with the integrated circuit 204. One end of the capacitor traces 408, 410 are interconnected with, via wire bond, the integrated 15694WOO1 (013-0615PCT1) 65 PATENT circuit 204, while the electrodes 207, 209 located at distal ends of the capacitor traces 408, 410 form part of the MEMS capacitive element 206. In some embodiments, the fully assembled IMD 150 can be coated in silicone to make it biocompatible. [00269] Figure 4E shows a portion of the IMD 150 (e.g., implantable pressure sensor) having direct wirebond interconnections to the integrated circuit 204 in accordance with embodiments herein. The top glass 412 and electrode 211 are not shown. The coil terminals 404 and 406 of the coil 402 are wirebonded to terminals 452 and 454, respectively, of the integrated circuit 204. Connector 472 extends between and is wirebonded or otherwise attached directly to a proximal end of the capacitor trace 408 and terminal 456 of the integrated circuit 204. Connector 474 extends between and is wirebonded or otherwise attached directly to a proximal end of the capacitor trace 410 and terminal 458 of the integrated circuit 204. In some embodiments the connectors 472 and 474 can be gold, gold plated, contain gold, etc. It should be understood that the location of the terminals 452–458 may vary based on the design of the integrated circuit 204. [00270] Referring also to the integrated circuit 204 in Figure 4B, the width 444 of the integrated circuit 204 is approximately the same as the width 460 of the proximal end 434 of the pedestal 416, and the height 462 of the pedestal 416 is slightly greater than the height 446 of the integrated circuit 204. In some embodiments, a distal side of the integrated circuit 204 can sit flush against the proximal end 434 of the pedestal 416, between beveled edges 464 and 466. Open area 468 of the cavity 422 extends between a proximal side 470 of the integrated circuit 204 and the inductive IMD coil 402. [00271] Figure 4F shows the portion of the IMD 150 (e.g., implantable pressure sensor) as discussed in Figure 4D having a power/energy storage capacitor 476 in accordance with embodiments herein. The power/energy storage capacitor 476 is wirebonded to terminals 478 and 480 of the integrated circuit 204. The power/energy storage capacitor 276 can also be referred to as a decoupling 15694WOO1 (013-0615PCT1) 66 PATENT capacitor. The capacitor 276 may be included because NFC powering may come in bursts or the strength of the field may vary, and the capacitor 276 helps to provide a consistent supply of charge to power the integrated circuit 204 in the midst of these variations. In some cases, the capacitor 276 may be included to provide a cleaner signal (e.g., flatten the variation) for the integrated circuit 204. [00272] Figures 4G and 4H illustrate views wherein the integrated circuit 204 is mounted to PCB 482 in accordance with embodiments herein. Turning first to Figure 4G, the coil terminals 404 and 406 of the inductive IMD coil 402 are tab welded to pads 484 and 486, respectively, of the PCB 482. Interconnect tab 473 is attached at a proximal end of the capacitor trace 408 and tab welded to pad 488 of the PCB 482. Interconnect tab 475 is attached to a proximal end of the capacitor trace 410 and tab welded to pad 490 of the PCB 482. It should be understood that the location of the pads 484–490 may vary based on the design of the PCB 482 and the integrated circuit 204. The interconnect tabs 473, 475 can be formed of gold, be gold plated, etc. In some embodiments, the pads 488, 490, 484, 486 can be gold plated. In other embodiments, the interconnect tabs 473, 375 can be welded to pads on the integrated circuit 204. In some embodiments, the pads can be 488, 490, 484, 486 can be attached to a surface of the integrated circuit 204 instead of to an intermediary PCB 482. According to new and unique embodiments, the interconnect tabs 473 and 475 can connect the capacitor traces 408 and 410 directly to the integrated circuit 204, such as by welding. Similarly, the coil terminals 404 and 406 can be directly connected to the pads 484 and 486 on the integrated circuit 204. [00273] The PCB 482 has a rounded proximal end 496. A width 497 at distal end 498 of the PCB 482 is smaller or approximately the same as the maximum width 463 of the pedestal 416 and can be larger than the width 444 of the integrated circuit 204 (shown in Figure 4B). In some embodiments, top surfaces of the tab welds of the PCB 482 sit below the top surface of the pedestal 416. 15694WOO1 (013-0615PCT1) 67 PATENT [00274] Turning to Figure 4H, this side view shows the integrated circuit 204 mounted to bottom side 492 of the PCB 482 by, for example only, flip chip bonding. The pad 488 is shown on top side 494 of the PCB 482. The power/energy storage capacitor 476 is mounted to the bottom side 492 of the PCB 482, and the PCB 482 interconnects the power/energy storage capacitor 476 and the integrated circuit 204. The PCB 482 provides the interconnections between the integrated circuit 204 and the inductive IMD coil 402 (shown in Figure 4A), facilitating and/or conveying/transmitting power and communications. The bottom surface of the integrated circuit 204 can be affixed to a lower surface 495 of the pedestal 416 with an adhesive layer 499. [00275] Figures 4I and 4J show top and isometric views, respectively, of the IMD 150 (e.g., implantable pressure sensor) that utilizes tab welding as discussed in Figure 4G in accordance with embodiments herein. The integrated circuit 204 (not shown) is mounted to a bottom side of the PCB 482. The IMD 150 is shown with the electrode 211 of the MEMS capacitive element 206 and the top glass 412 mounted over the assembly. The IMD 150 is powered by and communicates with the external device 104 using NFC. [00276] Figure 4K illustrates an exploded view of the implantable IMD coil 402 and sensor body 414 wherein the integrated circuit 204 (not shown) is mounted to the bottom side of the PCB 482 in accordance with embodiments herein. The coil terminals 404 and 406 are connected to the pads 484 and 486, respectively, of the PCB 482 as discussed in Figure 4G. In some embodiments, the assembly that includes the PCB 482, the integrated circuit 204, and the power/energy storage capacitor 476 (if used) are interconnected with the coil 402 in advance of mounting the implantable IMD coil 402 within the cavity 422. The integrated circuit 204 is attached to the pedestal 416 with the adhesive layer 499. [00277] Figure 4L shows a cross-sectional view of the IMD 150 (e.g., implantable pressure sensor) in accordance with embodiments herein. Portions of the implantable IMD coil 402 can be seen at either end. The integrated circuit 204 15694WOO1 (013-0615PCT1) 68 PATENT is mounted to the pedestal 416 with the adhesive layer 499. The gold interconnect tab 475 is indicated, directly connecting the capacitor trace 408 (not shown) to the integrated circuit 204. [00278] Figure 4M is a top view showing the interconnect tabs 473, 475 directly attaching to the integrated circuit 204 of the IMD 150 (e.g., implantable pressure sensor) in accordance with embodiments herein. The elements are described in further detail in the other illustrations. Near Field Communication [00279] The NFC reader (e.g., external device 104) is expected to be high power, for example, 4 W or higher as International Electrotechnical Commission (IEC) and Federal Communication Commission (FCC) limits will allow. The external device 104 is designed to be sensitive to pick up the load modulated signal from the IMD 150. In some embodiments, the external device 104 includes adaptive power control, where only the necessary amount of power is provided to the IMD 150 to mitigate concerns of overheating the IMD 150 than may result in inaccurate readings. [00280] Adaptive power control is based on receive signal strength indicator (RSSI) measurements. These measurements are done on the external reader side, which measures the strength of the signal it receives back from the IMD 150. In some cases, the closer the IMD 150 is to the external device 104, the larger the signal that is reflected back. If the IMD 150 is close, a lower level of power is needed to establish a successful link, so the external device 104 can decrease the amount of transmitted power if the reflected power (e.g., reflected from the IMD 150) is too high. In some embodiments, an RSSI measurement may also be accomplished by the IMD 150 to measure the amount of power that it receives. [00281] The adaptive power control sequence can start with the external device 104 starting at a low power output and gradually ramping the power output up until the external device 104 receives a response back from the IMD 150. Once 15694WOO1 (013-0615PCT1) 69 PATENT the external device 104 receives a response back, it can determine the received signal strength indicator (RSSI). If the RSSI is too high, such as compared to a predetermined threshold, the external device 104 can reduce the power output. If the RSSI is low, such as compared to the predetermined threshold or a different second threshold, then the external device 104 can increase the power. In some embodiments, with every communication packet exchange, the external device 104 can assess the RSSI and adjust the power accordingly. In other embodiments, the external device 104 can assess the RSSI and adjust the power accordingly based on a predetermined time period, number of communication packet exchanges, etc. [00282] The system can operate in a request-response mode. At least 100 samples/second are achieved. In some embodiments, the external device 104 can request one sample at a time, or in other embodiments, samples can be buffered by the integrated circuit 204 so that multiple samples are sent with each request. [00283] The NFC transmission generated by the NFC block 216 of the integrated circuit 204 follows the NFC protocol and will include pressure data, unique identifier (UID) 242 (e.g., serial number), and Cyclic Redundancy Check (CRC) (e.g., error detection). According to new and unique embodiments, the external device 104 can utilize NFC to energize and receive communications simultaneously from multiple IMDs 150, 152 as each IMD 150, 152 has a UID 242. The external device 104 can also communicate with other IMDs within the body that use NFC and may have their own power source. The external device 104 can identify the source of the received data based on the UID. [00284] The pressure measurement is accomplished while NFC power is applied by the external device 104 as there is no power storage on the IMD 150 (e.g., implantable pressure sensor). Thus, proper filtering to minimize or eliminate noise from the NFC power needs to be implemented to ensure the NFC field does not cause inaccuracies in the measurement. 15694WOO1 (013-0615PCT1) 70 PATENT [00285] The circuit needs to be designed so that the NFC field does not over- voltage the circuitry, while the system needs to ensure the silicon does not overheat and result in inaccuracies in the measurement. Calibrating the Pressure Sensor [00286] Figure 5 illustrates an example process flow for calibrating the IMD 150 (e.g., implantable pressure sensor) in accordance with embodiments herein. This process may be accomplished during manufacturing, such as after the IMD 150 is fully assembled and in advance of the IMD 150 being allocated to a patient. The operations of Figure 5 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server, local computer, or more generally within a health care system. Optionally, the operations of Figure 5 may be partially implemented by the IMD 150 and partially implemented by another processing device and/or system. It should be recognized that while the operations of Figure 5 are described in a somewhat serial manner, one or more of the operations may be continuous and/or performed in parallel with one another. [00287] At 502, one or more processors or circuits direct an external device 104 to transmit an energizing NFC signal. In some embodiments, the coil transmitting the NFC may be within six inches of the IMD 150. The inductive IMD coil 202 is energized and the resonant capacitor resonates with the inductive IMD coil 202. [00288] At 504, the one or more processors or circuits measure/determine the resonant frequency of the resonant capacitor. [00289] At 506, the one or more processors or circuits determine whether the resonant frequency of the resonant capacitor is within an ideal resonance, such as within a predetermined range of 13.56 MHz. If not within the predetermined range, the process flows to 508 and the one or more processors or circuits adjust the capacitance by, for example, programmably wiring trim bits (e.g., different 15694WOO1 (013-0615PCT1) 71 PATENT capacitors in an array) in or out of the circuit. In some embodiments, the swapping in or out of the capacitors in the array is controlled by switches that are closed or opened based on the trim bits. For example, in some cases, coarse trim bits (controlling larger capacitors) may be adjusted/swapped first for larger capacitance change. After the resonant frequency is remeasured, the resonant capacitor can be fine-tuned with finer trim bits (controlling smaller capacitors). The process returns to 508 to evaluate the resonant frequency of the resonant capacitor. [00290] If the frequency of the resonant capacitor is within the predetermined range at 506, the process flows to 510 and the one or more processors or circuits pressurize the IMD 150. For example, the IMD 150 may be placed within a pressure chamber capable of increasing and decreasing pressure at a predetermined rate and/or in a stepped fashion over a predetermined pressure range. [00291] At 512, the one or more processors or circuits determine the capacitance of the MEMS capacitive element 206 at the particular pressure and convert the capacitance to a digital word, such as with the capacitance to digital converter. The pressure data 256 is sent to the NFC block 216 for transmission via NFC to the external device 104. [00292] At 514, the one or more processors or circuits determine whether values have been collected over a desired predetermined range. In some embodiments, the predetermined range can be from 500 mmHg to 1020 mmHg. If more values are to be collected, the process returns to 512. It should be understood that the pressurization can be increased (or decreased) continuously and at a constant rate, while the reading of the capacitance can occur at a predetermined frequency to ensure a desired pressure resolution. [00293] When all of the pressure data is collected, converted to digital and transmitted to the external device 104 via NFC, at 516 the one or more processors or circuits fit a second order polynomial to the capacitance versus pressure relation to determine coefficient values and offsets, generally referred to as calibration 15694WOO1 (013-0615PCT1) 72 PATENT information. These coefficient values and offsets can be due to temperature and dielectric effect. [00294] At 518, the one or more processors or circuits transmit the calibration information via NFC from the external device 104 to the NFC block 216, and the NFC block 216 directs the memory 210 to store the calibration information 244. In some embodiments, the calibration information 244 will only be written once; however, the integrated circuit 204, in other embodiments, allows for up to five writes, either through rewritable memory or by using five times the amount of OTP memory. For example, the IMD 150 may be recalibrated to compensate for changes in aging components. [00295] At 520, the one or more processors or circuits write the unique serial number or other identifier(s) to the memory 210 of the integrated circuit 204. Implanting the Pressure Sensor [00296] Figure 6 illustrates an example process flow for identifying and baselining the IMD 150 (e.g., implantable pressure sensor) during implantation in accordance with embodiments herein. The operations of Figure 6 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system. Optionally, the operations of Figure 6 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 6 are described in a somewhat serial manner, one or more of the operations may be continuous and/or performed in parallel with one another. [00297] At 602, prior to implant, the IMD 150 is placed near the external device 104. In some embodiments, the maximum temperature range for this operation is 5 to 40 degrees Celsius. 15694WOO1 (013-0615PCT1) 73 PATENT [00298] At 604, one or more processors or circuits direct the external device 104 to transmit NFC signal to energize the IMD 150. [00299] At 606, the one or more processors or circuits transmit a message over NFC to request that the integrated circuit 204 transmit the serial number. [00300] At 608, the one or more processors or circuits, such as of the NFC block 216, generate and send an information request 238 to the memory 210. [00301] At 610, the one or more processors or circuits access the UID 242 (e.g., serial number) stored within the memory 210 and return the UID 242 (e.g., serial number) via the requested information 240. [00302] At 612, the one or more processors or circuits, such as of the NFC block 216, prepare and transmit a message over NFC to send the UID 242 (e.g., serial number) to the external device 104. In some embodiments, the external device 104 can display the serial number on a display or user interface and/or compare the retrieved serial number to an expected serial number to ensure that the serial number of or associated with the IMD 150 to be implanted is properly documented and associated with (e.g., assigned to) the patient. [00303] After the IMD 150 is implanted within the patient, such as in the pulmonary artery, aortic artery, a chamber of the heart, etc., at 614 the one or more processors or circuits direct the external device 104 to take readings from the IMD 150. For example, the external device 104 transmits the energizing NFC signal, and receives, via NFC, packets that include the digitized capacitance information. The NFC block 216 can build the packets including calibration information 244, UID 242, and/or other identifying information. [00304] While the external device 104 is receiving readings from the IMD 150, at 616 readings can be acquired from a pressure catheter (e.g., right heart catheter) to detect pressure. In some embodiments, the pressure can be measured using components included in the delivery catheter. [00305] At 618, the pressure detected by the IMD 150 is compared to the pressure detected by the pressure catheter. 15694WOO1 (013-0615PCT1) 74 PATENT [00306] If a difference is determined between the two pressure measurements at 618, at 620 an offset to the baseline information is determined. [00307] At 622, the one or more processors or circuits accept the baseline offset and modify the baseline information. As one example, the offset may be determined and entered manually at the external device. Additionally, or alternatively, pressure measurements from a catheter may be electronically conveyed/transmitted to the external device which then automatically calculates the offset. [00308] AT 624, the one or more processors or circuits transmit the baseline information, via NFC, to the integrated circuit 204. [00309] At 626, the one or more processors or circuits, such as of the NFC block 216, direct the memory 210 to save the baseline information 258. [00310] Optionally, at 628, the one or more processors or circuits transmit a patient identifier, via NFC, to the integrated circuit 204, and the one or more processors or circuits direct the memory 210 to save the patient identifier. For example, a patient identification (ID) number, social security number, etc., may be entered into the external device 104 via a graphical user interface and/or received electronically and saved. This may, for example, be used to ensure that the collected data is assigned to the correct patient, as well as assist with the correlation of data if multiple IMDs 150 are implanted. [00311] In some embodiments, during a follow-up procedure, the physician may choose to insert a pressure catheter to re-baseline the sensor. The re- baseline can then be programmed into the IMD 150 through NFC into the memory 210 allocated for baseline information 258. The integrated circuit 204 shall allow for up to 16 writes of the baseline information 258, either through rewritable memory, or using 16 times the amount of OTP. Acquiring Pressure Readings 15694WOO1 (013-0615PCT1) 75 PATENT [00312] Figure 7 illustrates an example process flow for acquiring pressure readings sensed by the IMD 150 (e.g., implantable pressure sensor) in accordance with embodiments herein. The operations of Figure 7 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system. Optionally, the operations of Figure 7 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 7 are described in a somewhat serial manner, one or more of the operations may be continuous and/or performed in parallel with one another. Figure 7 is discussed together with Figures 1A, 1B, and 3. [00313] At 702, the external device 104 is positioned near or in contact with the patient and also near the implanted location of the IMD 150. For example, to detect pressure readings of the pulmonary artery, the patient may be instructed by a clinician where along their torso to position the external device 104. As discussed herein, the external device 104 may be a pillow, blanket, belt, or included within another garment, be comprised of more than one piece wherein the coil or antenna is held within a portion close to the patient and interconnected with a computer, phone, base station, and/or other external device. [00314] In some embodiments, the patient may have more than one implanted pressure sensor that can be sensed with the external device 104 positioned in one place. In other embodiments, the patient may be instructed to move the external device 104 to one or more other location proximate their body to read other implantable pressure sensors. The below process flow is written from the perspective of a single pressure sensor; however, if more than one implantable pressure sensor is powered by the external device 104, each powered implantable pressure sensor will collect pressure data and transmit the data to the external device 104. 15694WOO1 (013-0615PCT1) 76 PATENT [00315] At 704, one or more processors or circuits direct the external device 104 to transmit NFC signal to energize the IMD 150. The patient may select an option, such as through a graphical user interface (GUI), to direct the external device 104 to take the pressure reading. The external device 104 can respond, for example, to a selection via a keyboard or GUI, a voice command, a command received via an external device such as an application on a patient’s phone, a command received via the internet such as from a clinician, and/or responsive to a preset time. [00316] At 706, as the NFC powers the integrated circuit 204, the one or more processors or circuits, such as of the NFC block 216, transmit a measurement request 254 to the C/D converter 212. The one or more processors or circuits can also transmit an information request 238 to the memory 210, requesting the UID 242, calibration information 244, baseline information 258, as well as any other identification information such as a patient ID. [00317] At 708, the one or more processors or circuits determine the capacitance of the MEMS capacitive element 206 and convert the capacitance to a digital word, such as with the C/D converter 212. [00318] At 710, the one or more processors or circuits transmit the pressure data 256 to the NFC block 216. [00319] At 712, the one or more processors or circuits transmit the UID 242 (e.g., serial number) and calibration information 244 from the memory 210 to the NFC block 216 via requested information 240. [00320] At 714, the one or more processors or circuits prepare a packet or payload of data including the pressure data 256 and the requested information 240 (e.g., UID 242 and calibration information 244) to send to the external device 104 using NFC. For example, the packet of data can be encoded to form encoded pressure data, preferably including an error bit and encrypted. 15694WOO1 (013-0615PCT1) 77 PATENT [00321] At 716, the one or more processors or circuits use NFC telemetry 252, to transmit the packet using NFC. In some embodiments, a plurality of packets can be transmitted in a burst. [00322] At 718, the one or more processors or circuits receive the packet at the external device 104. The packet can be stored in a memory on the external device 104 until manually deleted, for a predetermined period of time, until transmitted to an external health system, and the like. [00323] At 720, the one or more processors or circuits determine whether more data is to be collected. For example, a typical reading or collection session can be 18 seconds of data captured at 100 Hz (or 250 Hz). Other lengths of time and frequency is contemplated. [00324] If more data is to be collected, the process returns to 706. It should be understood that the process of determining the capacitance of the MEMS capacitive element 206, converting it to a digital word, and transmitting the data over NFC to the external device 104 occurs thousands of times during the typical reading. For example, in some embodiments, the capacitance value can be sampled at a specified sampling frequency without a break in time until the time duration (e.g., 18 seconds) is reached. [00325] If no more data is to be collected, the process flows to 722. Optionally, if data is to be acquired from another implantable pressure sensor requiring the patient to relocate the external device 104, the one or more processors or circuits may direct the patient to move the external device 104 to the next location. [00326] At 724, the one or more processors or circuits transmit the pressure data from the external device 104 to a healthcare system, such as to an electronic location accessible by a clinician associated with the patient. [00327] In some embodiments, the patient may take one reading a day. In accordance with new and unique aspects, with the increased ease of use of utilizing NFC to acquire pressure data, patients may find it easy to take multiple 15694WOO1 (013-0615PCT1) 78 PATENT readings a data. This increase in data collection can result in improved disease and symptom tracking, diagnosis, and recommendations for treatment. For example, the pressure data can be correlated with time the patient takes a medication. The patient may be prompted, such as through the external device 104, to take measurements at particular times relative to ingestion to determine the efficacy of the medication and/or the dose. [00328] Figure 8 illustrates a digital healthcare system 800 implemented in accordance with embodiments herein. The system 800 utilizes signals detected by an IMD and/or an IPS, implanted for example in a patient’s pulmonary artery and/or other vessel, to determine pressures, arrythmia, valid/invalid heartbeats of a patient, etc. The healthcare system 800 may include wearable devices that communicate with an IMD, IPS, external device, and/or a remote database. As a result, the healthcare system 800 may monitor health parameters of a patient, including blood pressure, valid heartbeats, heart rate, HRV, cardiac output, and/or therapies applied utilizing the health parameters, and provide a diagnosis and/or recommendations for the patient based on the monitored health parameters, adjust treatment parameters, etc. [00329] The system 800 may be implemented with various architectures, that are collectively referred to as a healthcare system 820. By way of example, the healthcare system 820 may be implemented as described herein. The healthcare system 820 may be a patient care network, such as the Merlin.netTM patient care network operated by Abbott Laboratories (headquartered in the Abbott Park Business Center in Lake Bluff, Ill.) [00330] The healthcare system 820 is configured to receive data, including IMD data from a variety of external and implantable sources including, but not limited to, active IMDs 802 capable of delivering therapy to a patient, passive IMDs 804 (e.g., cardiac monitors, IPS) capable of generating data associated with a patient, wearable devices/sensors 808, and point-of-care (POC) devices 810 (e.g., at home or at a medical facility). The data from one or more of the external and/or 15694WOO1 (013-0615PCT1) 79 PATENT implantable sources is collected and communicated to one or more secure databases within the healthcare system 820. Optionally, the patient and/or other users may utilize a device, such as a smart phone, tablet device, external device 104, etc., to enter data and/or connect via NFC with the active IMDs 802, passive IMDs 804, wearable devices/sensors 808, and/or device 1210. Tuning Coil/Antenna to Optimize NFC Link [00331] Figure 9A illustrates a system 200 wherein the external device 104 uses NFC to communicate with and preferably power the IMD 150 in accordance with embodiments herein. The system 200 shows some of the components of the IMD 150 and the external device 104. In this example, the IMD 150 is an implantable pressure sensor. However, in other embodiments, the IMD 150 can be a different type of implantable device. As discussed above, the terms coil and antenna are herein used interchangeably. [00332] As discussed above with respect to Figure 2A, the IMD 150 includes the inductive IMD coil 202 (e.g., antenna) for communications and power transfer, the integrated circuit 204 (e.g., ASIC), and the Micro-Electromechanical Systems (MEMS) capacitive element 206 for use as a pressure transducer. The integrated circuit 204 further includes the IMD transceiver 208, memory 210, and, preferably the capacitance to digital (C/D) converter 212. [00333] Preferably, an IMD tunable matching network 205 is coupled between the IMD inductive IMD coil 202 and the integrated circuit 204. In some embodiments, the IMD tunable matching network 205 can be included on the integrated circuit 204, while in other embodiments, the IMD tunable matching network 205 can be located outside the integrated circuit 204. As discussed herein, the IMD tunable matching network 205 can be preferably dynamically tuned as the IMD 150 communicates bidirectionally with the external device 104. In some embodiments, the IMD tunable matching network 205 can be initially optimized 15694WOO1 (013-0615PCT1) 80 PATENT during manufacturing using switches and/or adjustable components. Then, when installed in the body, the IMD tunable matching network 205 can continue to be optimized using switches and/or adjustable components to create different IMD matching network configurations. [00334] The memory 210 is a tangible and non-transitory computer-readable storage medium. In addition to the information stored as discussed above, the memory 210 can further store information related to tuning the IMD tunable matching network 205, such as thresholds, search ranges, time intervals, etc. [00335] In some cases, the external device 104 can be configured to direct the integrated circuit 204 to store information in the memory 210. For example, during an implant procedure the external device 104 may direct the integrated circuit 204 to store calibration information, baseline information, and the like. The external device 104 can also be used to store new and/or updated calibration and/or baseline information at a later date, such as during another procedure or during an office visit. The external device 104 may also be capable of storing information related to tuning the inductive IMD coil 202, such as thresholds, search ranges, time intervals, etc. In other embodiments, an external device 104 may be designed for the patient to be used at home and may not have the capability to direct the integrated circuit 204 to write to the memory 210. Instead, a home-use external device 104 may be limited with respect to interactions with the IMD 150 to providing NFC and receiving communications. [00336] The external device 104 includes an inductive external coil 231 and an external transceiver 235 (e.g., capable of transmitting and/or receiving NFC). Preferably, an external tunable matching network 233 is coupled between the inductive external coil 231 and the external transceiver 235. As discussed herein, the external tunable matching network 233 can preferably be dynamically tuned as the external device 104 establishes communication with, and communicates bidirectionally with, the IMD 150. In some embodiments, the external tunable 15694WOO1 (013-0615PCT1) 81 PATENT matching network 233 can be optimized using switches and/or adjustable components to create different external matching network configurations. [00337] To optimize the system and NFC link, the inductive external coil 231 communicatively connected to the external device 104 may be designed with a size to generate a larger field, such as to ensure communication of up to six inches deep within the patient’s body. External coil dimensions of at least 4” to 12” (e.g., 10.16 cm to 30.48 cm) in radius may be used. In some embodiments, the inductive external coil 231 can either be embedded in a pillow or blanket to be positioned underneath or on top of the patient, or embedded in other concepts like a sash, belt, or garment. In cases such as a sash, the external antenna/coil dimensions can be larger than 12” (e.g., 30.48 cm). At least some components of the inductive external coil 231 can be conformable and/or flexible to better match contours of the patient, improving transmission between the external device 104 and the IMD 150. In some cases, the inductive external coil 231 may be connected to but housed separately from one or more other components of the external device 104. [00338] The IMD 150 includes a housing 214 that holds and encapsulates the components including the inductive IMD coil 202, the IMD tunable matching network 205, the integrated circuit 204, and MEMS capacitive element 206 to protect these components from the harsh organic environment of the body. The housing 214 may be hermetically sealed. [00339] It should be understood that the MEMS capacitive element 206 is an example and represents only one implantable sensor that may be used together with the new and unique aspects discussed herein. Integrated Circuit [00340] Figure 9B illustrates a block diagram of the preferable integrated circuit 204 in accordance with embodiments herein. Some components of Figure 9B are discussed above with respect to Figure 3A and are not further discussed in this section. The preferred integrated circuit 204 includes two main building blocks, 15694WOO1 (013-0615PCT1) 82 PATENT preferably the C/D converter 212 and preferably the NFC block 216. Preferably, additional blocks include temperature measurement, typically utilizing the temperature sensor 218, preferably the memory 210 (e.g., one-time- programmable (OTP) memory, non-volatile memory (NVM)), preferably power regulation block 220, and preferably IMD tunable matching network 205. In some cases, resonant capacitor and (optional) tuning trim 223 can be included off-chip. Preferably, the inductive IMD coil 202 is coupled with the IMD tunable matching network 205 included on the integrated circuit 204. [00341] Preferably, the NFC block 216 is interconnected to the inductive IMD coil 202 (e.g., antenna) / IMD tunable matching network 205 via connections 228, 230. The NFC block 216 preferably includes power harvesting 248 to collect energy from the transmitted NFC and provide power to the power regulation block 220 via connection 232, which in turn can power the memory 210 via connection 234, the C/D converter 212 via connection 236, and temperature sensor 218 via connection 237. For example, preferably, the temperature sensor 218 can monitor the temperature over a time period (e.g., 18 seconds, 30 seconds) that the integrated circuit 204 is expected to be powered during normal use to allow adjustments in the calibration, capacitance trimming, configuration of the IMD tunable matching network 205, etc. In some embodiments, hard coded logic (e.g., circuit, circuitry) of the integrated circuit 204 can accomplish requests, receive data, output data via NFC, etc. In other embodiments, the NFC block 216 includes and/or is in communication with one or more preferred processor 246 incorporated within the integrated circuit 204 that includes program instructions and is configured to accomplish requests, receive data, output data via NFC, and the like. [00342] The NFC block 216 can further include a preferred IMD receive signal strength indicator (RSSI) determination module 269 that can determine an IMD RSSI, which can be a measure of the strength or power of the NFC signal received by the IMD 150, typically measured in decibels (dB). For example, the IMD RSSI determination module 269 can be in communication with and receive 15694WOO1 (013-0615PCT1) 83 PATENT instructions from the processor 246. Preferably, the NFC block 216 can receive instructions within an NFC packet transmitted from the external device 104 requesting that the IMD RSSI determination module 269 determine the IMD RSSI. The IMD RSSI can be included in an NFC packet (e.g., data packet) and transmitted to the external device 104. [00343] The NFC block 216 can also include a preferred IMD matching network configuration module 271. The IMD matching network configuration module 271 can be in communication with and receive instruction from the processor 246. Preferably, the IMD matching network configuration module 271 can control switches and/or adjustable components of the IMD tunable matching network 205 to change the configuration of the IMD tunable matching network 205 and dynamically tune the antenna/coil 202. Additionally, and/or alternatively, the IMD matching network configuration module 271 can adjust adjustable components that can change capacitance, inductance, and/or resistance, and/or vary voltage such as to change the capacitance of varactor(s). [00344] The NFC block 216 can include a preferred IMD phase difference determination module 273. Preferably, the IMD phase difference determination module 273 can determine the phase difference between the transmit (e.g., IMD 150) and receive (e.g., external device 104) signals. If the IMD phase difference determination module 273 determines that the phase difference satisfies a threshold, such as being outside of a range, percentage, and/or number, the IMD phase difference determination module 273 can initiate tuning of one or both of the external tunable matching network 233 and the IMD tunable matching network 205. In some embodiments, the IMD phase difference determination module 273 can monitor the phase difference at predetermined time intervals, and/or as part of another process. [00345] In some embodiments, the at least one processor 246 or circuit of the integrated circuit 204 provides the ability to trim or configure the IMD tunable matching network 205 to optimize it for the NFC frequency. For example, the IMD 15694WOO1 (013-0615PCT1) 84 PATENT tunable matching network 205 can include a resonant capacitor that resonates with the coil 202; however, manufacturing and assembly variability may result in frequency variations. In some cases, it is desirable to trim the resonant capacitor so that it resonates at the NFC frequency of 13.56 MHz. For example, the NFC block 216 can have an on-chip resonant capacitor as well as the ability to trim the capacitor (shown collectively as IMD tunable matching network 205). In some embodiments, an array of capacitors can be wired in or out of circuit via trim bits. The trim bits can be programmable via the NFC interface and powering, ideally when the IMD 150 is fully packaged. For example, the telemetry controls the trimming (e.g., tells which trim bits to enable/disable) and the NFC powering provides the power needed to write into the memory 210. In some embodiments, the trim bits are programmed before the IMD 150 is implanted within a patient, such as during a factory process. [00346] Upon receiving power via the inductive IMD coil 202, the NFC block 216 can “wake up” and preferably send a measurement request 254 to the C/D converter 212. Preferably, the C/D converter 212, powered by the power regulation block 220, converts the capacitance into a digital word that represents the pressure within the area around the MEMS capacitive element 206 at the particular point in time. [00347] Once the pressure measurement is captured and converted into a digital word (e.g., digitized) by the C/D converter 212, preferably the pressure data is sent to the NFC block 216 for encoding (e.g., adding information such as error bit) to form encoded pressure data. Optionally, the encoded pressure data may further be encrypted (e.g., encryption 250). The encoded and/or encrypted pressure data is then utilized to modulate the return signal. Encoding and encryption are further discussed herein above. In some embodiments, the pressure data, along with data that identifies the IMD 150, the IMD RSSI, the IMD output frequency, the IMD matching network configuration, temperature data, etc., can be transmitted to the external device 104, such as in one or more packets. 15694WOO1 (013-0615PCT1) 85 PATENT External Device [00348] Figure 9C illustrates an exemplary external device 104 for communicating with an IMD 150 implanted within a body in accordance with embodiments herein. In some environments the IMD 150 can be one of the sensors discussed with respect to Figure 1A and/or another implanted sensor/device capable of NFC. The NFC reader (e.g., external device 104) is expected to be high power, for example, 1 W or higher as International Electrotechnical Commission (IEC) and Federal Communication Commission (FCC) limits will allow. The external device 104 is designed to be sensitive to pick up the load modulated signal from the IMD 150. [00349] The external device 104 is positioned outside of the patient. In some embodiments, the external device 104 may have components configured to interface with and/or contact skin and/or clothing of the patient, such as a pillow, garment, and the like. In some embodiments, the inductive external coil 231 (e.g., antenna) can be included on and/or within the components, and in some cases the inductive external coil 231 and/or external tunable matching network 233 can be conformable, i.e., components of the inductive external coil 231 and/or external tunable matching network 233 may flex, bend, and the like to conform to the patient. [00350] The external device 104 is capable of communicating (e.g., communications circuit 950) with other external device(s) 952, such as smart phones, cellular phones, watches, computers, laptops, tablets, programmers, etc., as well as communicating wirelessly and over wired communication technologies to convey/transmit information between remote servers, computers, etc. [00351] The external device 104 can include a programmable microcontroller 954 and/or other processor(s) and/or circuit(s) that controls various operations, including communicating with one or more IMDs 150, configuring the external tunable matching network 233, directing one or more IMD 150 to configure the IMD 15694WOO1 (013-0615PCT1) 86 PATENT 150 tunable matching network 205, and cardiac monitoring such as monitoring blood pressure. The microcontroller 954 can include a microprocessor (or equivalent control circuitry, one or more processors, etc.), RAM and/or ROM memory, logic and timing circuitry, state machine circuitry, I/O circuitry, ASIC, and the like. [00352] The inductive external coil 231 can power the IMD 150 and convey/transmit the external NFC signals to the IMD 150. The external device 104 also includes the external transceiver 235 (Figure 9A) that is capable of transmitting the external NFC signals having relatively different power levels, and receiving the NFC signals via the inductive external coil 231 that include IMD NFC signals, such as from the IMD 150. In some embodiments, the external transceiver 235 can simultaneously power multiple IMDs, and transmit and receive NFC signals to and from multiple IMDs. [00353] The external device 104 can also include an emission or output power level adjustment module 956 for selecting an output power of the external NFC signals. For example, the output power level adjustment module 956 can set an emission level to a relatively lower setting while initiating communication with an IMD 150. The output power level adjustment module 956 can increase the power up to a maximum power threshold (e.g., ramp up) until communication is established. In some embodiments, a power threshold may be set at 7 W, 8 W, 10 W, etc. The output power level adjustment module 956 can increase/decrease the output power in several ways. Non-limiting examples include directing an amplifier (e.g., adjust a gain adjustment), which may be included in the external transceiver 235, the inductive external coil 231, or elsewhere within the external device 104 to increase/decrease the output power and/or increase/decrease a current input power to the amplifier. [00354] In some embodiments, when initiating communication with the IMD 150, the external device 104 can start at a low level of power output and gradually ramp up the power until communication is reached. In some cases, the power 15694WOO1 (013-0615PCT1) 87 PATENT output may be increased slightly beyond this level to ensure enough margin. As an example, the external device 104 can start at 100 mW, then step up in 100-250 mW increments until successful communication occurs. If successful communication occurs at 2 W, the RSSI (received signal strength indicator) of the IMD 150 may be, for example, 1 mW. The external device 104 can then increase the power output to, for example, 2.5 W, to ensure enough margin. As a result, the RSSI of the IMD 150 will also increase, such as to 5 mW. At this point the external device 104 and IMD 150 may begin the telemetry/measurement process. The RSSI of the IMD 150 can be monitored so that if the RSSI increases too much, such as above a maximum threshold, the power output of the external device 104 can be decreased. If, however, the RSSI falls below a lower threshold, such as below 2 mW, the output power can be increased, such as to approximately 3 W, to return to an RSSI of approximately 5 mW. [00355] An output power determination module 958 can compare the output power to the power threshold, such as at time intervals set by a timer, based on a trigger, and/or as part of another process. For example, the output power determination module 958 may monitor the output power when the external device 104 is establishing connection with the IMD 150 to ensure that the output power does not exceed the power threshold, potentially damaging components within the IMD 150 and/or exceeding statutory regulations that limit radiation exposure. If the output power determination module 958 determines that the power threshold is satisfied (e.g., at or beyond a desirable limit), the output power determination module 958 can initiate one or more of i) tuning one or both of the external tunable matching network 233 and the IMD tunable matching network 205, ii) decrease the output power (output power level adjustment module 956), iii) initiate a message to the patient (e.g., display a message on a display, sound a tone or message, send a text message) to indicate that the external device 104 should be repositioned with respect to the IMD 150, or iv) terminate the attempt to establish communication and/or terminate the NFC communication with the IMD 150 to 15694WOO1 (013-0615PCT1) 88 PATENT prevent damage to either the external device 104 or the IMD 150 (e.g., over-heat, over-voltage). [00356] The external device 104 can include an RSSI determination module 960. In some embodiments, monitoring the IMD RSSI and/or external RSSI can be referred to as adaptive power control, wherein only the necessary amount of power is provided to the IMD 150 to mitigate concerns of overheating the IMD 150 that may result in inaccurate readings. Adaptive power control can also be used to ensure maximum power transfer. [00357] Adaptive power control is based on RSSI measurements. The external RSSI measurements can be accomplished by the external device 104, which measures the strength of the signal it receives back from the IMD 150. In some cases, the closer the IMD 150 is to the external device 104, the larger the signal that is reflected back. If the IMD 150 is close, a lower level of power is needed to establish a successful link, so the external device 104 can decrease the amount of transmitted power if the reflected power (e.g., reflected from the IMD 150) is too high. In some embodiments, an IMD RSSI measurement may also be accomplished by the IMD 150 (e.g., IMD RSSI determination module 269 of Figure 9B) to measure the amount of power that it receives. The IMD RSSI can be transmitted to the external device 104. In some embodiments, the IMD 150 can compare the IMD RSSI to an IMD RSSI threshold and if the threshold is satisfied (e.g., met, exceeded), the IMD 150 can send a request to the external device 104 to lower the output power. [00358] The adaptive power control sequence can start with the external device 104 starting at a low power output and gradually ramping the power output up until the external device 104 receives a response back from the IMD 150. Once the external device 104 receives a response back, it can determine the external RSSI. The power level can be referred to as a characteristic of interest (COI). If the external RSSI is too high, such as compared to a predetermined threshold, the external device 104 can reduce the power output (e.g., output power level 15694WOO1 (013-0615PCT1) 89 PATENT adjustment module 956). If the external RSSI is low, such as compared to the predetermined threshold or a different second threshold, then the external device 104 can increase the power. In some embodiments, with every communication packet exchange, the external device 104 can assess the external RSSI and adjust the power accordingly. In other embodiments, the external device 104 can assess the external RSSI and/or IMD RSSI and adjust the power accordingly based on a predetermined time period, number of communication packet exchanges, a trigger, etc. [00359] In some embodiments, the external device 104 can include a reflection coefficient module 962. For example, the external device 104 can determine a voltage level of and/or associated with IMD NFC signals returned from the IMD 150 and a voltage level of and/or associated with the external NFC signals transmitted by the external device 104. The voltage level can be referred to as a characteristic of interest (COI). The reflection coefficient can be determined as the ratio of the reflected wave (e.g., IMD NFC signals) to the incident wave (e.g., external NFC signals. It is desirable to minimize the reflection coefficient at the target frequency of 13.56 MHz. [00360] A phase difference determination module 964 can determine the phase difference between the transmit (external device 104) and receive (IMD 150) signals. If the phase difference determination module 964 determines that the phase difference satisfies a threshold, such as being outside of a range, percentage, and/or number, the phase difference determination module 964 can initiate tuning one or both of the external tunable matching network 233 and the IMD tunable matching network 205. In some embodiments, the phase difference determination module 964 can monitor the phase difference at predetermined time intervals, as the result of a trigger, and/or as part of another process. [00361] An IMD data determination module 966 can decode packets of information sent via the IMD NFC signals. For example, the external device 104 transmits the energizing external NFC signal, and receives, via IMD NFC signals, 15694WOO1 (013-0615PCT1) 90 PATENT packets that include the digitized capacitance information. The NFC block 216 (Figure 9B) can build the packets including calibration information 244, UID 242, and/or other identifying information, data measurements such as pressure, IMD RSSI, IMD output frequency, IMD matching network configuration, etc. [00362] An external matching network configuration module 968 can direct the external tunable matching network 233 and/or the IMD tunable matching network 205 to change configuration. In some embodiments, the external matching network configuration module 968 can reconfigure the external tunable matching network 233 to “sweep” the range of the external tunable matching network 233 to adjust the impedance of the external coil 231. In other embodiments, the external matching network configuration module 968 can reconfigure the external tunable matching network 233 through an impedance range that is less than a total range, in different sized step increments (course or fine adjustments), etc. In still further embodiments, the external matching network configuration module 968 can initiate a message to be included in a packet sent to the IMD 150 to direct the IMD 150 to reconfigure the IMD tunable matching network 205 according to certain parameters. [00363] A memory 970 or other storage medium stores program instructions, settings, thresholds, ranges, IMD data measurements, signal data such as pressure, data received from the IMD 150, etc. [00364] For example, the external device 104 can perform a method for managing inductive communication between an IMD 150 and an external device 104, wherein the external device 104 has an inductive external coil 231 (e.g., external antenna) configured to be located proximate to a body and the IMD 150 is configured to be located within the body. The external device 104 transmits, by the inductive external coil 231, inductive external near field communication (NFC) signals to an inductive IMD coil 202 (e.g., IMD antenna). The inductive external coil 231 receives inductive IMD NFC signals from the inductive IMD coil 202. A characteristic of interest (COI) can be determined based on the inductive IMD NFC 15694WOO1 (013-0615PCT1) 91 PATENT signals, such as by but not limited to the RSSI determination module 960 and/or the reflection coefficient module 962. The external device 104 can dynamically tune at least one of the inductive external coil 231 or the inductive IMD coil 202 based on the COI. In some embodiments, the inductive IMD NFC signals include IMD data measurements. [00365] In some cases, the COI is a voltage level of (or associated with) the IMD NFC signals, and the external device 104 can dynamically tune the inductive external coil 231 or the inductive IMD coil 202 based on a reflection coefficient of (associated with) the COI. In other cases, the COI is a voltage level of (associated with) the IMD NFC signals, and the external device 104 can dynamically tune the inductive external coil 231 by changing at least one parameter of an external tunable matching network 233 communicatively connected to the inductive external coil 231 to minimize a reflection coefficient associate with the COI. Changing at least one parameter of the external tunable matching network 233, such as by using the external matching network configuration module 968, can comprise opening or closing one or more switches in the external tunable matching network, adjusting one or more adjustable components in the external tunable matching network 233, and/or increasing or decreasing an input voltage to the external tunable matching network to adjust an impedance of the inductive external coil 231. [00366] In other cases, the COI is an IMD received signal strength indicator (RSSI), and the COI is included in a data packet transmitted by the IMD coil. In some embodiments, wherein the COI is an IMD RSSI, the method for managing inductive communication further includes determining an external RSSI of, based on, and/or associated with the inductive IMD NFC signals, and wherein the dynamically tuning further includes configuring a network configuration of an external tunable matching network 233 communicatively connected to the inductive external coil 231 or an IMD tunable 15694WOO1 (013-0615PCT1) 92 PATENT matching network 205 communicatively connected to the inductive IMD coil 202 to maximize one of the IMD RSSI or external RSSI. [00367] In some embodiments, the external matching network configuration module 968 can dynamically tune the inductive external coil 231 by changing at least one parameter of an external tunable matching network 233 communicatively connected to the inductive external coil 231 or at least one parameter of an IMD tunable matching network 205 communicatively connected to the inductive IMD coil 202. In response to changing the at least one parameter, the method for managing inductive communication further includes transmitting, by the inductive external coil 231, successive inductive external NFC signals to the inductive IMD coil 202, receiving, via the inductive external coil 231, successive inductive IMD NFC signals from the inductive IMD coil 202, the successive inductive IMD NFC signals including IMD data measurements, determining a successive COI based on the successive inductive IMD NFC signals, and the dynamically tuning further comprising dynamically tuning at least one of the inductive external coil 231 or the inductive IMD coil 202 based on the successive COI. [00368] In some cases, the external device 104 can set an output power of the inductive external coil 231 at an initial level, and in response to not receiving, via the inductive external coil 231, the IMD NFC signals from the inductive IMD coil 202, the output power level adjustment module can increase the output power of the inductive external coil 231. In some embodiments, the output power determination module can determine if an output power of the external device 104 satisfies a power threshold, and in response to the output power satisfying the power threshold, the output power level adjustment module 956 can decrease the output power. [00369] In other cases, the phase difference determination module can determine if a phase difference between the inductive external NFC signals of the inductive external coil 231 and the inductive IMD NFC signals of the inductive IMD coil 202 satisfies a phase difference threshold, and in response to the phase 15694WOO1 (013-0615PCT1) 93 PATENT difference satisfying the phase difference threshold, the external matching network configuration module 968 can change at least one parameter of an external tunable matching network 233 communicatively connected to the inductive external coil 231 or at least one parameter of an IMD tunable matching network 205 communicatively connected the inductive IMD coil 202. [00370] In some cases, in response to a decrease in an output power of the external device 104, changing, with the external matching network configuration module 968, at least one parameter of an external tunable matching network 233 communicatively connected to the inductive external coil 231, transmitting, by the inductive external coil 231, successive inductive external NFC signals to the inductive IMD coil 202, receiving, via the inductive external coil 231, successive inductive IMD NFC signals from the inductive IMD coil 202, the successive inductive IMD NFC signals including IMD data measurements, determining a successive COI based on the successive IMD NFC signals, and the dynamically tuning further comprising dynamically tuning the inductive external coil 231 based on the successive COI. [00371] In other cases, in response to a time interval being satisfied, the method further comprises evaluating i) an IMD RSSI, ii) an external RSSI, iii) a reflection coefficient of (associated with) the COI, iv) a phase difference between the inductive external NFC signals and the inductive IMD NFC signals, or v) an output power of the external device 104. Matching Networks [00372] Figures 10A, 10B, 10C, and 10D illustrate examples of tunable matching networks that can be used with the inductive IMD coil 202 (e.g., IMD antenna) and/or the inductive external coil 231 (e.g., external antenna). Various topologies can be used and are not limited to the examples shown herein. For example, in Figure 10A, a pi-network is illustrated, in Figure 10B an L-match network is illustrated, in Figure 10C a T-match network is shown, and in Figure 15694WOO1 (013-0615PCT1) 94 PATENT 10D a back-to-back L-match network is shown. It should be understood that any combination of these antenna matching networks can be used, e.g., L-match, T- match, back-to-back Lmatch, such as by replicating one topology in series/parallel, multiple different networks in series/parallel, etc., and the arrangement of components is not limited to those shown and/or discussed. For example, any of the tunable matching networks in Figures 10A, 10B, 10C, and 10D can include more or less components, different components than shown, and components arranged in different configuration/order, including, but not limited to, switches, adjustable components, resistors, capacitors, inductors, and the like. The components and changes to the tunable matching networks can be referred to as parameters, such that changing a parameter of the tunable matching network can include one or more of changing the position of a switch to include or exclude components, changing or adjusting the value of an adjustable component, and/or varying the level of input power to the tunable matching network. [00373] In some embodiments, the matching networks will include at least one switch, such that at least one component can be included or excluded from the circuit depending upon the position of the switch and/or adjusting the values of one or more adjustable components, resulting in at least two different matching network configurations. [00374] Additionally, or alternatively, one or more adjustable components can be included in the matching networks with or without one or more switches. For example, varactor(s) can be included in a matching network to change the capacitance with voltage (i.e., varying the voltage to vary the capacitance). Additionally, or alternatively, potentiometer(s) can be included in a matching network to change the resistance of the matching network. It should be understood that a combination of these components can be used wherein one or more adjustable component and/or switch can be included within each matching network, and that other adjustable components not specifically identified may also be used. 15694WOO1 (013-0615PCT1) 95 PATENT [00375] As discussed herein, a matching network can be used to tune an antenna/coil to its transceiver circuit. Typically, these matching networks consist of capacitors, inductors, resistors, etc., and are static values. As the inductive IMD coil 202 and the inductive external coil 231 are in environments that are variable, such as due to human body composition, placement, and distance (e.g., distance between the IMD and external coils/antennas), the IMD and external tunable matching networks 205, 233 are designed so that the components can be dynamically and automatically adjusted. The adjustment can be done by implementing a bank of components and switching them in and out with switches, and/or adjusting adjustable components. [00376] In some embodiments, to control the switching/adjusting and ensure that it is maximizing the link performance, the external device 104 can be designed to constantly and/or periodically (e.g., based on time intervals, number of packets received from the IMD 150, every packet received from the IMD 150, result of a test of external and/or IMD RSSI, result of measuring the reflection coefficient, result of determining phase difference between the transmit and receive signals) adjust/sweep the antenna matching components of the external and/or IMD tunable matching networks 233, 205 to stay at maximum signal point (e.g., power, voltage current). For example, if the RSSI has drifted, the external device 104 may direct the external matching network configuration module 968 to adjust/sweep the external antenna matching components to stay at maximum signal point, and/or the external device 104 may direct the IMD matching network configuration module 271 to adjust/sweep the IMD antenna matching components to stay at maximum signal point. The adjustments of the IMD and external tunable matching networks 205, 233 can be accomplished iteratively, serially, substantially simultaneously, continuously, etc. In other embodiments, if the reflection coefficient, which is the ratio of the reflected wave to the incident wave, is too high, the external and IMD matching network configuration modules 292, 271 can be directed in a similar 15694WOO1 (013-0615PCT1) 96 PATENT manner to adjust/sweep the external and/or IMD antenna matching components to minimize the reflection coefficient at the target frequency (e.g., 13.56 MHz). [00377] Figure 10A illustrates an example of the IMD tunable matching network 205a and the external tunable matching network 233a having a simple pi- match network topology in accordance with embodiments herein. The external tunable matching network 233a is interconnected with the inductive external coil 231 and the external transceiver 235 of the external device 104, and the IMD tunable matching network 205a is interconnected with the inductive IMD coil 202 and the integrated circuit 204 and/or IMD transceiver 208. It should be understood that other components than shown may be included in the external tunable matching network 233a and the IMD tunable matching network 205a. [00378] The external tunable matching network 233a matches the output impedance of the external device 104 (e.g., power amplifier in, of, and/or associated with the external transceiver 235) to the impedance of the inductive external coil 231. The external tunable matching network 233a includes capacitors (C1-C8), inductor L1, and switches (S1-S6). Similarly, the IMD tunable matching network 205a is also a pi-match network topology which matches the output impedance of the IMD 150 to the inductive IMD coil 202.The IMD tunable matching network 205a includes capacitors (C10-C17), inductor L2, and switches (S10- S16). While the switches S1-S6 and S10-S15 are shown in the open position, each network configuration can have different numbers of open or closed switches. It should be noted that there is no requirement for the external and IMD tunable matching networks 233, 205 to be the same topology. [00379] Although the example pi-match network is shown having inductor(s) in the middle and capacitors on the side, a different pi-match network could be used that has capacitor(s) in the middle with inductors on the side. Further, resistor(s) can be included in parallel or in series with other components. Although the implementation of the matching network can vary, new and unique embodiments as discussed herein include the use of switches and/or adjustable 15694WOO1 (013-0615PCT1) 97 PATENT components to allow different configurations of the matching networks 205, 233, advantageously allowing the matching networks 205, 233 to be modified dynamically to optimally tune the antenna(s) to changes in the environment. This provides a technological improvement to the field of medical communication that utilizes NFC. [00380] In some embodiments, the external device 104 and IMD 150 can be programmed, such as based on calculations, to identify which switch(s) to change to increase or decrease frequency of the associated antenna and by how much. This provides the advantage of decreasing the time required to evaluate different matching network configurations of the matching networks 205, 233. [00381] In other embodiments, successive approximation could be used. Again, the external device 104 and IMD 150 can be programmed, such as based on calculations, to identify which switch(s)/adjustable components provide the biggest impact. If a matching network configuration is evaluated that has gone too far or made too big of a change, other switches/adjustable components associated with smaller changes can be open/closed until the matching is optimized. [00382] As the impedance changes due to variations of surrounding human body tissue, position of external device 104 relative to IMD 150, and antenna shape, the performance will degrade (which can be detected by increased reflection, reduced receive signal strength indicator (RSSI), and/or phase differences between the transmit and receive signals). The system can detect those degradations and control the switches S1-S6, S10-S15 to switch in and out capacitors C2-C8, C11-C17 (and/or other components) to re-optimize the matching and keep the system operating in the region of maximum performance. [00383] While a pi-network is illustrated, the same concept applies to other matching topologies including L-match, T-match, back-back-Lmatch, and any combination of those options. Figure 10B illustrates an example wherein the external tunable matching network 233b of the external device 104 is an L-match topology in accordance with embodiments herein. The external tunable matching 15694WOO1 (013-0615PCT1) 98 PATENT network 233b includes capacitor C20, C21, inductor L20, and switch S20, although more components are contemplated. Figure 10C illustrates an example wherein the external tunable matching network 233c of the external device 104 is a T-match topology in accordance with embodiments herein. In this example, the external tunable matching network 233c includes capacitors C30, C31, inductors L30, L31, and switch S30. It should be understood that these are examples only, and that more components and/or more switches may be included. Any of the topologies in Figures 10A, 10B, 10C, and 10D can include more or less components, including switches, adjustable components, resistors, capacitors, inductors, and the like, depending on system requirements. Also, the matching network may include a single switch, providing two different configurations, one with the switch open and a second one with the switch closed. [00384] Although not shown in Figures 10B and 10C, the IMD 150 can also include an IMD tunable matching network 205 that is the same as or different from the external tunable matching network 233b, 233c. It is not required for the IMD and external tunable matching networks 205, 233 to be the same. [00385] Figure 10D illustrates an example of the IMD tunable matching network 205d and the external tunable matching network 233d having a back-to- back L-match network topology in accordance with embodiments herein. The external tunable matching network 233d is interconnected with the external coil 231 and the external transceiver 235 of the external device 104, and the IMD tunable matching network 205d is interconnected with the inductive IMD coil 202 and the integrated circuit 204 and/or IMD transceiver 208. [00386] The external tunable matching network 233b includes capacitors C40, C41, C42, C43, inductors L40, L41, L42, L43, and switches S41, S42, S43, S44, although more components are contemplated. The IMD tunable matching network 205d includes capacitors C50, C51, C52, C53, inductors L51, L52, L53, L54, and switches S50, S51, S52, S53. In this example, switches S41, S43, S51, 15694WOO1 (013-0615PCT1) 99 PATENT and S54 are arranged to include or exclude serial component(s), such as an inductor, in the matching network configuration. [00387] Although the IMD tunable matching network 205d and the external tunable matching network 233d are illustrated with the same topology, the system is not so limited. Each of the IMD tunable matching network 205 and external tunable matching network 233 can have any of the topologies disclosed herein. Tuning the Coils/Antennas and Receiving IMD Data Measurements [00388] Figure 11 illustrates an example process flow 1100 for setting an output power of the external device 104 (e.g., reader) for acquiring IMD data measurements, sensed and/or determined by the IMD 150, in accordance with embodiments herein. In some embodiments, the acquired data can be pressure readings and the IMD 150 can be a pressure sensor. The operations of Figure 11 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system. Optionally, the operations of Figure 11 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 11 are described in a somewhat serial manner, one or more of the operations may be continuous, performed in a different order, and/or performed in parallel with one another. [00389] At 1102, the external device 104 is positioned near or in contact with the patient and also near the implanted location of the IMD 150. For example, to detect pressure readings of the pulmonary artery, the patient may be instructed by a clinician where along their torso to position the external device 104. As discussed herein, the external device 104 may be a pillow, blanket, belt, or included within another garment, be comprised of more than one piece wherein the coil or antenna is held within a portion close to the patient and interconnected with a computer, 15694WOO1 (013-0615PCT1) 100 PATENT phone, base station, and/or other external device. For example, the inductive external coil 231 and/or external tunable matching network 233 can be conformable to the shape of the patient. [00390] The patient may select an option, such as through a graphical user interface (GUI), to direct the external device 104 to take the reading, such as the pressure reading. The external device 104 can respond, for example, to a selection via a keyboard or GUI, a voice command, a command received via an external device such as an application on a patient’s phone, a command received via the internet such as from a clinician, and/or responsive to a preset time. [00391] In some embodiments, the patient may have more than one IMD 150, 152 that can be powered and sensed with the external device 104 positioned in one place. In other embodiments, the patient may be instructed to move the external device 104 to one or more other location proximate their body to read other IMDs. The below process flow is written from the perspective of a single IMD 150; however, if more than one IMD is powered by the external device 104 (e.g., IMD 152 of Figure 1A), each powered IMD 150, 152, for example, will collect pressure data (or other data) and transmit the data to the external device 104. In some embodiments, the external device 104 can simultaneously communicate with another IMD that has its own battery source. In that case, the other IMD can receive NFC communications from the external device 104 and/or wake up as a result of detecting the external NFC signals, and send IMD NFC signals, such as packets, to the external device 104 at the same time the external device 104 is receiving IMD NFC signals from the IMD 150. [00392] At 1104, one or more processors or circuits set an output power of the external device 104 at an initial level. The initial level may be preset, such as by the manufacturer or clinician, at 100 mW, 200 mW, etc. In other embodiments, the initial level can be based on a previous level, such as based on one or more prior sessions. For example, if the external device 104 communicated with the IMD 150 successfully at 4 W, 4.5 W, and 4 W in the previous three sessions, 15694WOO1 (013-0615PCT1) 101 PATENT respectively, the one or more processors or circuits may set the initial level of the output power of the external device 104 at 3.5 W, or slightly less than the lowest output power level. This provides the advantage of quicker connectivity by learning the power requirements of the particular system, wherein variabilities exist between patients based on positioning of the external device 104, depth of the IMD 150, etc. When connectivity is quickly achieved, the length of the collection session can be minimized, thus improving patient compliance. [00393] At 1106, the one or more processors or circuits direct the external device 104 to transmit external NFC signals to energize the IMD 150. [00394] At 1108, the one or more processors or circuits determine whether the external device 104 received a response from the IMD 150. In some embodiment, the one or more processors of the external device 104 measure how much power is received back from the IMD 150 to determine the external RSSI. In some embodiments, the external device 104 may wait a predetermined time for a response. In some embodiments, the one or more processors or circuits of the IMD 150 determine the IMD RSSI, which is an indication of how much power the IMD 150 received, and transmit the IMD RSSI to the external device 104. [00395] If the external device 104 does not receive a response from the IMD 150, process flows to 1110 and the one or more processors or circuits determine whether the output power level satisfies a power threshold. For example, a power threshold can be a maximum output power level based on regulatory requirements, anatomical depth of the IMD 150, etc., and prevents over-voltage conditions and over-heating of the IMD 150. In some embodiments, the power threshold can be set at 7 W, 8 W, 9 W, 10 W, and the like. [00396] If the output power level satisfies the power threshold, process flows to 1112 and the one or more processors or circuits can output an indication to the patient to adjust the external device 104, and/or specifically the inductive external coil 231, relative to the IMD 150 and restart the process. In some embodiments, a message indicating a power level can be logged/displayed. In some cases, a 15694WOO1 (013-0615PCT1) 102 PATENT message can be logged and/or transmitted to the clinician, indicating a positioning error, an output power too high error, and/or the potential non-responsiveness of the IMD 150. [00397] Returning to 1110, if the output power level does not satisfy the power threshold, process flows to 1114 and the one or more processors or circuits can increase the output power level, such as in 100-250 mW increments. In some embodiments, the output power level can be increased by increasing a gain amplifier on a power amplifier of the external transceiver 235 or by increasing the input power to the power amplifier. [00398] Returning to 1106, the one or more processors or circuits direct the external device 104 to transmit external NFC signals at the increased output power level to energize the IMD 150. [00399] The method flows to 1108 and again monitors for a response from the IMD 150. When the external device 104 receives a response from the IMD 150, process flows to 1116. In some cases, the output power can be increased to ensure enough margin. Until evaluated again, such as in Figure 18 discussed further below, the current output power level is used to transmit external NFC signals to the IMD 150. [00400] In some embodiments, the external device 104 can display a power level and/or coupling quality output to the patient. This can have the advantageous effect of providing feedback to the patient regarding placement of the inductive external coil 231, effect of patient movement on the reading, and the like. A visual indicator, such as a battery indictor with horizonal or vertical lines indicating the degree of optimization accomplished at the current placement, and/or auditory cues could be provided to the patient to prompt patient behavior. [00401] In some embodiments, the IMD 150 can transmit packets of information via NFC telemetry 252. One or more packets can include information associated with the IMD 150, such as pressure measurements (e.g., a capacitance converted to a digital word), a UID 242, calibration information 244, baseline 15694WOO1 (013-0615PCT1) 103 PATENT information 258, as well as any other identification information such as a patient ID. In some embodiments, the packet of data or payload can be encoded, including an error bit and encrypted. In other embodiments, a plurality of packets can be transmitted in a burst. [00402] The one or more processors or circuits of the external device 104 receive the packet(s). The packet(s) can be stored in a memory 970 on the external device 104 until manually deleted, for a predetermined period of time, until transmitted to an external health system, and the like. [00403] The external device 104 continues to power the IMD 150 and collect data until a collection session is complete. For example, a typical reading or collection session can be 18 seconds of data captured at 100 Hz (or 250 Hz). Other lengths of time and frequency are contemplated. [00404] While the collection session is in process and data is being collected, process flows to 1118. At 1118, the process flows simultaneously to one or more of Figures 12-18, and the one or more processors or circuits one or more of i) identify the external matching network configuration that provides the best reflection coefficient to tune the inductive external coil 231 to its external transceiver 235, ii) identify the external matching network configuration that provides the highest RSSI to tune the inductive external coil 231 to its external transceiver 235, iii) identify the external matching network configuration that provides the least phase difference, iv) monitor the output power, and v) monitor the RSSI. Simultaneously, the one or more processors continue to receive packets from the IMD 150 that can include IMD data measurements, calibration information, IMD identification information, etc. In accordance with embodiments herein, the system dynamically, e.g., in real-time, receives IMD NFC signals from the inductive IMD coil 202 that contain data measurements, and the external device 104 determines at least one characteristic of interest (COI) from the IMD NFC signals that contain the data measurements. 15694WOO1 (013-0615PCT1) 104 PATENT [00405] At 1120, the one or more processors or circuits determine if the data collection session is complete. If more IMD data is to be collected, the process returns to 1118. It should be understood that the process of determining the capacitance of the MEMS capacitive element 206, converting it to a digital word, and transmitting the data over NFC to the external device 104 occurs thousands of times during the typical reading. For example, in some embodiments, the capacitance value can be sampled at a specified sampling frequency without a break in time until the time duration (e.g., 18 seconds) is reached. [00406] If no more data is to be collected, the process flows to 1122, and the one or more processors or circuits stop transmitting external NFC signals and transmit the pressure data and/or other data received from the external device 104 to a healthcare system, such as to an electronic location accessible by a clinician associated with the patient. The transmission of the data to another location may occur as soon as the data collection is complete, at a later time, based on a schedule, on demand, etc. [00407] In some embodiments, the patient may take one reading (e.g., one collection session) a day. In accordance with new and unique aspects, with the increased ease of use of utilizing NFC to acquire pressure data, patients may find it easy to take multiple readings a day. This increase in data collection can result in improved disease and symptom tracking, diagnosis, and recommendations for treatment. For example, the pressure data can be correlated with a time the patient takes a medication. The patient may be prompted, such as through the external device 104, to take measurements at particular times relative to ingestion to determine the efficacy of the medication and/or the dose. [00408] Figure 12 describes a process for dynamically tuning the inductive external coil 231 to minimize the reflection coefficient, Figure 13 describes a process for dynamically tuning the inductive external coil 231 based on RSSI, and Figure 14 describes a process for dynamically tuning the inductive external coil 231 based on phase difference. The system can be designed to use one of the 15694WOO1 (013-0615PCT1) 105 PATENT processes, to use all of the processes at different times (e.g., serially) or to conduct all of the processes simultaneously. As discussed herein, dynamically tuning the inductive external coil 231 can be accomplished in real-time, such as during a beginning, middle, or end of a data exchange session, which includes an interval of time during which the IMD 150 sends data measurements to the external device 104. In some embodiments, when the IMD 150 is a pulmonary artery pressure (PAP) sensor, the external device 104 can dynamically tune the inductive external coil 231 at any time while simultaneously receiving data measurements, such as PAP measurements, from the PAP sensor. In other embodiments, the process for dynamically tuning the inductive external coil 231 can occur before the IMD 150 conducts measurements and transmits IMD data measurements to the external device 104, and/or the measurement and transmission of IMD data measurements can be suspended while the dynamic tuning of the inductive external coil 231 is accomplished. [00409] Figure 12 illustrates an example process flow 1200 for dynamically receiving IMD data measurements and tuning the inductive external coil 231 to minimize the reflection coefficient in accordance with embodiments herein. In some embodiments, the IMD data measurements can be pressure readings and the IMD 150 can be a pressure sensor. In other embodiments, the dynamic tuning of the inductive external coil 231, by sweeping the components of the external tunable matching network 233 (e.g., sweeping frequency) can be accomplished in less than one second. The operations of Figure 12 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system. Optionally, the operations of Figure 12 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 12 are described in a somewhat serial manner, one or more of the operations may be 15694WOO1 (013-0615PCT1) 106 PATENT continuous, performed in a different order, and/or performed in parallel with one another. [00410] At 1202, one or more processors or circuits configure a first external matching network configuration. For example, the external device 104 can configure the external tunable matching network 233 of the inductive external coil 231 to a first external matching network configuration. For example, the external matching network configuration module 968 (Figure 9C) can command particular switches S1-S6 of the external tunable matching network 233a (Figure 10A) open or closed and/or set values/parameters for adjustable components. In some embodiments, the first impedance can be achieved by, for example, opening all switches or closing all switches. In other embodiments, a course sweep of the matching components could be implemented, wherein not all of the possible configurations are evaluated, or a fine sweep could be used, wherein all of the possible configurations are evaluated. In still further embodiments, a course or fine sweep of the possible external matching network configurations can be determined within a certain range (e.g., around the configuration previously determined to result in the minimum reflection coefficient). [00411] At 1204, the one or more processors or circuits transmit external NFC signals using the first external matching network configuration. [00412] At 1206, the one or more processors or circuits of the IMD 150 receive the external NFC signals and at 1208, the one or more processors or circuits transmit IMD NFC signals that can include IMD data measurements. [00413] At 1210, the one or more processors or circuits of the external device 104 receive the IMD NFC signals. [00414] At 1212, the one or more processors or circuits determine a characteristic of interest (COI) associated with the IMD NFC signals and the first external matching network configuration. In the example of Figure 12, the COI is a voltage level and can be used to determine the reflection coefficient. In other embodiments, the COI can be an amplitude. 15694WOO1 (013-0615PCT1) 107 PATENT [00415] At 1214, the one or more processors or circuits determine a COI of and/or associated with the transmitted external NFC signals and the first external matching network configuration. The COI can be a voltage level. [00416] At 1216, the one or more processors or circuits, such as of the external device 104, calculate the reflection coefficient associated with the first external matching network configuration as the ratio of the reflected wave (e.g., IMD NFC signals) to the incident wave (e.g., external NFC signals.) The reflection coefficient and the associated external matching network configuration can be saved, at least temporarily, in the memory 970. [00417] At 1218, the one or more processors or circuits determine whether another external matching network configuration should be evaluated to determine the associated reflection coefficient. [00418] If another configuration is to be evaluated, at 1220, the one or more processors or circuits change at least one parameter of the inductive external coil 231 by configuring the second external matching network configuration, and the process returns to 1204. For example, a parameter may be the position of a switch, a setting of an adjustable component, or a voltage input level, but is not so limited. [00419] 1204-1218 are repeated for the second external matching network configuration, transmitting second (successive) external NFC signals, receiving second (successive) IMD NFC signals, determining a second COI of and/or associated with the second IMD NFC signals and the second external matching network configuration, and determining the associated reflection coefficient. The process is repeated for any successive configuration of the external tunable matching network 233. [00420] By way of example only, the external matching network configuration module 968 can direct first switch S1 to open, and then the reflection coefficient is determined. The external matching network configuration module 968 can successively direct each of the switches S2-S6 to open, and then the associated, 15694WOO1 (013-0615PCT1) 108 PATENT successive reflection coefficient is determined. In some embodiments, not all of the switches may be opened or closed during the evaluation process. [00421] Once the associated reflection coefficients have been determined for the external matching network configurations to be evaluated, process flows to 1222 and the one or more processors or circuits identify the external matching network configuration having the minimum reflection coefficient. The identified external matching network configuration is used to transmit the external NFC signals until a trigger is received, a time interval is satisfied, etc., indicating that the reflection coefficient should be evaluated. [00422] Additionally, and/or alternatively, the one or more processors or circuits can iteratively evaluate the change between successive reflection coefficient values. For example, the external matching network configurations may be cycled through and evaluated for improvement. When the reflection coefficient value does not improve (e.g., lower), the one or more processors or circuits may select the previous external matching network configuration. [00423] Additionally, and/or alternatively, the IMD tunable matching network 205 can be configured. For example, in Figure 12, based on a command from the external device 104 or a command from within the IMD 150 (e.g., a trigger, an automatic setting, interval of time), the IMD 150 can change at least one parameter of the inductive IMD coil 202 by configuring the IMD matching network configuration. In some embodiments, the IMD 150 can transmit, via a packet, information regarding the instant IMD matching network configuration, which the external device 104 can correlate with the measured power reflected back from the inductive IMD coil 202, and determine the associated reflection coefficient. The external device 104 can receive IMD data associated with at least two of the IMD matching network configurations and can respond to the IMD 150 with a command/instruction indicating what IMD matching network configuration to use. 15694WOO1 (013-0615PCT1) 109 PATENT [00424] In some cases, the external device 104 can also verify that the output frequency of the inductive external coil 231 is within a predetermined range of 13.56 MHz. [00425] In some embodiments, process of Figure 12 can be used to dynamically receive IMD data measurements while tuning the IMD tunable matching network 205 of the inductive IMD coil 202 to minimize the reflection coefficient. Multiple configurations of the IMD tunable matching network 205 can be evaluated to identify the IMD matching network configuration with the minimum reflection coefficient. In some cases, the evaluation of the IMD tunable matching network 205 can alternate with the evaluation of the external tunable matching network 233, occur simultaneously, interactively, etc. [00426] Figure 13 illustrates an example process flow 1300 for dynamically receiving IMD data measurements and tuning the inductive external coil 231 based on IMD RSSI and external device RSSI in accordance with embodiments herein. In some embodiments, the IMD data measurements can be pressure readings and the IMD 150 can be a pressure sensor, and the RSSI can be measured in decibels (dB) of power. The operations of Figure 13 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system. Optionally, the operations of Figure 13 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 13 are described in a somewhat serial manner, one or more of the operations may be continuous, performed in a different order, and/or performed in parallel with one another. [00427] As the IMD 150 is powered by harvesting power from the external device 104, maximum power consumption is very critical, and thus maximum power transfer is very critical. According to new and unique embodiments herein, dynamically tuning the inductive external coil 231 and/or inductive IMD coil 202 15694WOO1 (013-0615PCT1) 110 PATENT provides an improvement in the technology of communicating between implantable and external devices using NFC. By maximizing power transfer, the output power of the external device 104 can be kept within an acceptable range, instead of increasing the power level to the IMD 150 which may result in the IMD 150 having to dissipate the power as heat within the body. [00428] The different matching network configurations can be determined and achieved as discussed above in Figure 12. For example, the external matching network configuration module 968 (Figure 9C) can command particular switches S1-S6 of the external tunable matching network 233a (Figure 10A) open or closed, set values/parameters for adjustable components, perform course and/or fine sweeps, evaluate some of all configurations, etc. The RSSI values and associated external matching network configuration and/or IMD matching network configuration can be stored in the memory 970 at least temporarily. [00429] At 1302, one or more processors or circuits configure a first external matching network configuration. For example, the external device 104 can configure the external tunable matching network 233 of the inductive external coil 231 to a first external matching network configuration. [00430] At 1304, the one or more processors or circuits transmit external NFC signals using the first external matching network configuration and request the IMD RSSI, such as by sending a request packet. [00431] At 1306, the one or more processors or circuits of the IMD 150 receive the request, and at 1308, the one or more processors or circuits determine the IMD RSSI, which is an indication of how much power the IMD 150 received. The COI in this example is the IMD RSSI that is of and/or associated with the first external matching network configuration. [00432] At 1310, the one or more processors or circuits transmit IMD NFC signals that include the IMD RSSI and IMD data measurements, such as in one or more data packet. In some embodiments, the IMD matching network configuration associated with the IMD RSSI may also be sent. 15694WOO1 (013-0615PCT1) 111 PATENT [00433] At 1312, the one or more processors or circuits of the external device 104 receive the IMD NFC signals and the IMD RSSI. [00434] At 1314, the one or more processors or circuits determine an external RSSI (e.g., COI) of and/or associated with the first external matching network configuration (and optionally, the IMD matching network configuration). For example, the one or more processors or circuits of the external device 104 measure how much power is received back from the IMD 150. [00435] At 1316, the one or more processors or circuits determine whether another external matching network configuration should be evaluated. [00436] If another configuration is to be evaluated, at 1318 the one or more processors or circuits change at least one parameter of the inductive external coil 231 by configuring the next external matching network configuration, and the process returns to 1304. For example, the external matching network configuration module 968 can close or open one or more of switches S1-S6, change the value or setting of an adjustable component, or change the voltage input level. [00437] 1304-1316 are repeated for the second external matching network configuration, transmitting second (successive) external NFC signals, determining a second IMD RSSI (e.g., COI), receiving second (successive) IMD NFC signals including the IMD RSSI (e.g., COI), and determining a second external RSSI (e.g., COI) of and/or associated with the second IMD NFC signals and the second external matching network configuration. The process is repeated for any successive configuration of the external tunable matching network 233. [00438] Once the associated IMD and external RSSI have been determined for the external matching network configurations to be evaluated, process flows to 1320 and the one or more processors or circuits identify the external matching network configuration having the highest RSSI values, while remaining within boundaries, indicating a maximized amount of power transfer. For example, the one or more processors can identify the external matching network configuration to maximize one of the IMD RSSI or external RSSI, or to maximize both of the IMD 15694WOO1 (013-0615PCT1) 112 PATENT RSSI and external RSSI. The identified external matching network configuration is used to transmit the external NFC signals until a trigger is received, a time interval is satisfied, etc., indicating that the RSSIs should be evaluated. In some embodiments, the external matching network configuration can be selected based on i) both the highest IMD RSSI and external RSSI, ii) the highest IMD RSSI, or iii) the highest external RSSI. [00439] In some embodiments, the process of Figure 13 can be used to dynamically receive IMD data measurements while tuning the inductive IMD coil 202 based on IMD RSSI and external device RSSI. Multiple configurations of the IMD tunable matching network 205 can be evaluated to identify the IMD matching network configuration with i) both the highest IMD RSSI and external RSSI, ii) the highest IMD RSSI, or iii) the highest external RSSI. In some cases, the evaluation of the IMD tunable matching network 205 can alternate with the evaluation of the external tunable matching network 233, occur simultaneously, interactively, etc. [00440] Figure 14 illustrates an example process flow 1400 for dynamically receiving IMD data measurements and tuning the inductive external coil 231 to optimize the phase difference in accordance with embodiments herein. In some embodiments, the IMD data measurements can be pressure readings and the IMD 150 can be an implantable pressure sensor. In other embodiments, the dynamic tuning of the inductive external coil 231, by sweeping the components of the external tunable matching network 233 (e.g., sweeping frequency) can be accomplished in less than one second. The operations of Figure 14 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system. Optionally, the operations of Figure 14 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 14 are described in a somewhat serial manner, one or more of the operations may be 15694WOO1 (013-0615PCT1) 113 PATENT continuous, performed in a different order, and/or performed in parallel with one another. [00441] At 1402, one or more processors or circuits configure a first external matching network configuration. For example, the external device 104 can configure the external tunable matching network 233 of the inductive external coil 231 to a first external matching network configuration. For example, the external matching network configuration module 968 (Figure 9C) can command particular switches S1-S6 of the external tunable matching network 233a (Figure 10A) open or closed and/or set values/parameters for adjustable components. In some embodiments, the first impedance can be achieved by, for example, opening all switches or closing all switches. In other embodiments, a course sweep of the matching components could be implemented, wherein not all of the possible configurations are evaluated, or a fine sweep could be used, wherein all of the possible configurations are evaluated. In still further embodiments, a course or fine sweep of the possible external matching network configurations can be determined within a certain range (e.g., around the configuration previously determined to result in the minimum phase difference). [00442] At 1404, the one or more processors or circuits transmit external NFC signals using the first external matching network configuration. [00443] At 1406, the one or more processors or circuits of the IMD 150 receive the external NFC signals and at 1408, the one or more processors or circuits transmit IMD NFC signals that can include IMD data measurements. [00444] At 1410, the one or more processors or circuits of the external device 104 receive the IMD NFC signals. [00445] At 1412, the one or more processors or circuits, such as of the external device 104, determine the phase difference associated with the first external matching network configuration as the difference between the received IMD NFC signals and the transmitted external NFC signals. The phase difference and the associated external matching network configuration can be saved, at least 15694WOO1 (013-0615PCT1) 114 PATENT temporarily, in the memory 970. In this example, the phase difference is a COI based on the IMD NFC signals. The phase difference is also a COI based on the external NFC signals. [00446] At 1414, the one or more processors or circuits determine whether another external matching network configuration should be evaluated to determine the associated phase difference. [00447] If another configuration is to be evaluated, at 1416, the one or more processors or circuits change at least one parameter of the inductive external coil 231 by configuring the second external matching network configuration, and the process returns to 1404. For example, a parameter may be the position of a switch, a setting of an adjustable component, or a voltage input level, but is not so limited. [00448] 1404-1414 are repeated for the second external matching network configuration, transmitting second (successive) external NFC signals, receiving second (successive) IMD NFC signals, determining a second COI (e.g., the associated phase difference) associated with the second IMD NFC signals, the second external NFC signals, and the second external matching network configuration. The process is repeated for any successive configuration of the external tunable matching network 233. [00449] By way of example only, the external matching network configuration module 968 can direct first switch S1 to open, change an adjustable component value, vary an input voltage, etc., and then the phase difference is determined. The external matching network configuration module 968 can successively configure to external tunable matching network 233, and then the associated, successive phase difference is determined. In some embodiments, not all of the configurations may be evaluated. [00450] Once the associated phase differences have been determined for the external matching network configurations to be evaluated, process flows to 1418 and the one or more processors or circuits identify the external matching network configuration having the optimal phase difference. The identified external 15694WOO1 (013-0615PCT1) 115 PATENT matching network configuration is used to transmit the external NFC signals until a trigger is received, a time interval is satisfied, etc., indicating that the phase difference should be evaluated. [00451] Additionally, and/or alternatively, the one or more processors or circuits can iteratively evaluate the change between successive phase differences. For example, the external matching network configurations may be cycled through and evaluated for improvement. When the phase difference does not improve, the one or more processors may select the previous external matching network configuration. [00452] Additionally, and/or alternatively, the IMD tunable matching network 205 can be configured. For example, in Figure 14, based on a command from the external device 104 (e.g., a trigger, an automatic setting, interval of time), the IMD 150 can change at least one parameter of the IMD coil 202 by configuring the IMD matching network configuration. In some embodiments, the IMD 150 can transmit, via a packet, information regarding the instant IMD matching network configuration, which the external device 104 can correlate with the associated phase difference. The external device 104 can receive IMD data associated with at least two of the IMD matching network configurations and can respond to the IMD 150 with a command/instruction indicating what IMD matching network configuration to use. [00453] Alternatively, the IMD 150 can determine the phase difference between the external NFC signals (received at the IMD 150) and the IMD NFC signals (transmitted by the IMD 150). The IMD 150 can configure the IMD matching network configurations and determine the associated phase differences until the optimal phase difference is determined. [00454] In some embodiments, the process of Figure 14 can be used to dynamically receive IMD data measurements while tuning the inductive IMD coil 202 to optimize the phase difference. Multiple configurations of the IMD tunable matching network 205 can be evaluated to identify the IMD matching network 15694WOO1 (013-0615PCT1) 116 PATENT configuration with the optimal phase difference. In some cases, the evaluation of the IMD tunable matching network 205 can alternate with the evaluation of the external tunable matching network 233, occur simultaneously, interactively, etc. [00455] Figures 15-18 illustrate several process flows that can be used to determine when to tune the external tunable matching network 233 and/or the IMD tunable matching network 205 while the external device 104 is dynamically receiving IMD data measurements. While each of the methods are initiated based on a time interval being satisfied, it should be understood that other factors can initiate the method, such as the number of packets received, a temperature indication from the IMD 150 that is within a predetermined range, bad, lost or missed data packets, etc. For example, a time interval has an associated predetermined duration of time between starting and ending points, and the satisfaction of the time interval indicates that the predetermined duration of time has passed since the starting point. The various process flows can run concurrently, serially, simultaneously, etc. [00456] Although the process flows of Figures 15-18 discuss tuning (e.g., dynamically tuning) the external tunable matching network 233 of the external device 104, if should be understood that time interval(s) can equally be applied to determine when/if to tune the IMD tunable matching network 205 of the IMD 150. [00457] Figure 15 illustrates an example process flow 1500 for tuning the inductive external coil 231 based on a time interval in accordance with embodiments herein. For example, every time the inductive external coil 231 is tuned, the time interval (e.g., time interval 1) can be reset. This has the advantage of tuning the inductive external coil 231 at least at a predetermined frequency of time to ensure that the communication parameters remain optimized. The operations of Figure 15 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system. Optionally, the operations of Figure 15 may be partially 15694WOO1 (013-0615PCT1) 117 PATENT implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 15 are described in a somewhat serial manner, one or more of the operations may be continuous, performed in a different order, and/or performed in parallel with one another. [00458] At 1502, the NFC communication between the external device 104 and the IMD 150 is established, and the external device is receiving the IMD data measurements transmitted by the IMD 150, as discussed in 1116 of Figure 11. [00459] At 1504, the one or more processors or circuits determine if a time interval (e.g., time interval 1) is satisfied. For example, the time interval 1 can be programmed by the physician or the manufacturer. As a non-limiting example, the time interval may be programmed to have a predetermined duration of time of a few seconds or longer between starting and ending points. Additional or other time intervals can be programmed to have different predetermined durations of time between their starting and ending points. [00460] If the time interval 1 is satisfied at 1504 (e.g., the predetermined duration of time of the time interval 1 has passed), flow passes to 1506 and the one or more processors or circuits accomplish the tuning of the inductive external coil 231 and/or inductive IMD coil 202 in accordance with Figure 12, Figure 13, and/or Figure 14. When the external tunable matching network 233 and/or IMD tunable matching network 205 has been configured, flow passes to 1508 and the one or more processors or circuits reset the time interval 1, and flow returns to 1504. [00461] In some embodiments, the inductive IMD coil 202 can be tuned simultaneously and/or serially with respect to the inductive external coil 231. For example, process flows may utilize offset time interval 1, such that the external coil 231 is tuned, followed by tuning the IMD coil 202, and so on. [00462] Figure 16 illustrates an example process flow 1600 for tuning the external coil 231 based on phase difference between the transmit and receive 15694WOO1 (013-0615PCT1) 118 PATENT signals in accordance with embodiments herein. For example, every time the inductive external coil 231 is tuned, the time interval (e.g., time interval 2) can be reset. This has the advantage of tuning the inductive external coil 231 to ensure that the communication parameters remain optimized. The operations of Figure 16 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system. Optionally, the operations of Figure 16 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 16 are described in a somewhat serial manner, one or more of the operations may be continuous, performed in a different order, and/or performed in parallel with one another. [00463] At 1602, the NFC communication between the external device 104 and the IMD 150 is established and the external device is receiving the IMD data measurements transmitted by the IMD 150, as discussed in 1116 of Figure 11. [00464] At 1604, the one or more processors or circuits determine if a time interval (e.g., time interval 2) is satisfied. For example, the time interval 2 can be programmed by the physician or the manufacturer and can be shorter or less than time interval 1. In other embodiments, the one or more processors or circuits can monitor for a predetermined number of packets to be transmit and/or received, then initiate measuring the phase difference between the transmit and receive signals. [00465] If the time interval 2 is satisfied at 1604 (e.g., the predetermined duration of time of the time interval 2 has passed), process flows to 1606 where the one or more processors or circuits measure the phase difference between the output of the inductive external coil 231 and the phase of the signal received from the IMD 150. 15694WOO1 (013-0615PCT1) 119 PATENT [00466] At 1608, the one or more processors or circuits determine if the phase difference between the transmit and receive signals satisfies a phase difference threshold. In some embodiments, the phase difference threshold can be a range, percentage, and/or number indicating an upper limit for phase differences between the signals. If the phase difference threshold is not satisfied, i.e., the phase difference is within an acceptable range, flow passes to 1612 and the one or more processors reset the time interval 2. [00467] If the phase difference is satisfied at 1608, flow passes to 1610 and the one or more processors or circuits accomplish the tuning of the inductive external coil 231 and/or inductive IMD coil 202 in accordance with Figure 12, Figure 13, and/or Figure 14. In some embodiments, the sweep of the components of the external tunable matching network 233 and/or IMD tunable matching network 205 may be over a smaller range, and the sweep may evaluate a greater number of configurations within the smaller range compared to a broader “ball park” range. [00468] When the external tunable matching network 233 and/or IMD tunable matching network 205 has been configured, flow passes to 1612, the one or more processors or circuits reset the time interval 2, and flow returns to 1604. [00469] Although Figure 16 is written from the perspective of the external device 104, additionally, optionally, or alternatively, the phase difference evaluation may be accomplished by the inductive IMD coil 202 to evaluate the phase difference at the inductive IMD coil 202 and tune the IMD tunable matching network 205 as needed. [00470] In other embodiments, a process flow similar to Figure 16 may be implemented for tuning the inductive external coil 231 based on reflection coefficient. The one or more processors or circuits can determine if a time interval (e.g., time interval 2 or other time interval less than time interval 1) is satisfied. The one or more processors or circuits can determine the associated reflection coefficient (e.g., COI). If the reflection coefficient satisfies a reflection coefficient 15694WOO1 (013-0615PCT1) 120 PATENT threshold, the one or more processors or circuits can accomplish the tuning of the external coil 231 and/or IMD coil 202 in accordance with Figure 12, Figure 13, and/or Figure 14. [00471] Figure 17 illustrates an example process flow 1700 for tuning the inductive external coil 231 based on the IMD RSSI and/or the external RSSI in accordance with embodiments herein. The operations of Figure 17 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system. Optionally, the operations of Figure 17 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 17 are described in a somewhat serial manner, one or more of the operations may be continuous, performed in a different order, and/or performed in parallel with one another. [00472] At 1702, the NFC communication between the external device 104 and the IMD 150 is established and the external device is receiving the IMD data measurements transmitted by the IMD 150, as discussed in 1116 of Figure 11. [00473] At 1704, the one or more processors or circuits determine if a time interval (e.g., time interval 3) is satisfied. For example, the time interval 3 can be programmed by the physician or the manufacturer and can be less than time interval 1 of Figure 15. In other embodiments, the one or more processors or circuits can monitor for a predetermined number of packets to be transmit and/or received, then initiate the determination of the IMD RSSI and the external RSSI. [00474] If the time interval 3 is satisfied at 1704 (the predetermined duration of time of the time interval 3 has passed), process flows to 1706 and the one or more processors request the IMD RSSI and determine the external RSSI, as discussed previously in Figure 13. 15694WOO1 (013-0615PCT1) 121 PATENT [00475] At 1708, the one or more processors or circuits determine if the IMD RSSI and/or the external RSSI satisfy one or more RSSI threshold (e.g., percentage, range, predetermined value, programmed value, value based on IMD RSSI when communication was established, value based on external RSSI when communication was established). As discussed above, it is important to maximize power transfer. For example, in some embodiments, if the IMD RSSI falls below a percentage of external device RSSI, e.g., approximately 70%, 72%, 75%, the RSSI threshold may be satisfied. If the RSSI threshold is not satisfied, i.e., the IMD RSSI and/or external RSSI are within an acceptable range, flow passes to 1712 and the one or more processors or circuits reset the time interval 3. In other embodiments, the RSSI threshold may be a value, such as mW, based on the initial output power or a predetermined or programmed value. For example, if the IMD RSSI was 5 mW when communication between the IMD 150 and external device 104 was established, the RSSI threshold may be set at 2 mW, based on the initial output power. If the IMD RSSI decreases to 2 mW, flow passes to 1710. It should be understood that the RSSI threshold may be associated with the external RSSI, the IMD RSSI, both, and/or that each of the external RSSI and IMD RSSI can have an associated RSSI threshold. [00476] If the RSSI threshold is satisfied at 1708, flow passes to 1710 and the one or more processors or circuits accomplish the tuning of the inductive external coil 231 and/or IMD coil 202 in accordance with Figure 12, Figure 13, and/or Figure 14. [00477] When the external tunable matching network 233 has been configured, flow passes to 1712 and the one or more processors or circuits reset the time interval 3, and flow returns to 1704. [00478] Referring again to 1708, alternatively and/or additionally, when the RSSI threshold is satisfied, the output power may be increased to increase the IMD RSSI and external RSSI. 15694WOO1 (013-0615PCT1) 122 PATENT [00479] Figure 18 illustrates an example process flow 1800 for tuning the inductive external coil 231 based on output power of the external device 104 in accordance with embodiments herein. The operations of Figure 18 may be implemented by hardware, firmware, circuitry and/or one or more processors or circuits housed partially and/or entirely within the IMD 150, a local external device 104, remote server or more generally within a health care system. Optionally, the operations of Figure 18 may be partially implemented by the IMD 150 and partially implemented by a local external device, remote server or more generally within a health care system. It should be recognized that while the operations of Figure 18 are described in a somewhat serial manner, one or more of the operations may be continuous, performed in a different order, and/or performed in parallel with one another. [00480] At 1802, the NFC communication between the external device 104 and the IMD 150 is established and the external device is receiving the IMD data measurements transmitted by the IMD 150, as discussed in 1116 of Figure 11. [00481] At 1804, the one or more processors or circuits determine if a time interval (e.g., time interval 4) is satisfied. For example, the time interval 4 can be programmed by the physician or the manufacturer and can be less than time interval 1 of Figure 15. In other embodiments, the one or more processors or circuits can monitor for a predetermined number of packets to be transmit and/or received, then initiate the determination of the output power. [00482] If the time interval 4 is satisfied at 1804 (the predetermined duration of time of the time interval 4 has passed), process flows to 1806 and the one or more processors or circuits determine the output power of the external device 104. [00483] At 1808, the one or more processors or circuits determine if the output power satisfies an output power threshold. For example, the output power determined at 1808 can be compared to the output power set during the process of Figure 11, to a predetermined maximum (e.g., 7.5 W, 8 W, 8.5 W). If the output power threshold is not satisfied, i.e., the output power is within an acceptable 15694WOO1 (013-0615PCT1) 123 PATENT range, flow passes to 1814 and the one or more processors or circuits reset the time interval 4. [00484] If the output power threshold is satisfied at 1808, flow passes to 1810 and the one or more processors or circuits decrease the output power, such as to a second power threshold. In some embodiments, the output power can be decreased to a predetermined value, and/or set to the output power level set at 1108 in Figure 11 when communication was established. [00485] At 1812, the one or more processors or circuits accomplish the tuning of the inductive external coil 231 and/or inductive IMD coil 202 in accordance with Figure 12, Figure 13, and/or Figure 14. [00486] When the external tunable matching network 233 has been configured, flow passes to 1814 and the one or more processors or circuits reset the time interval 4, and flow returns to 1804. Closing [00487] It should be clearly understood that the various arrangements and processes broadly described and illustrated with respect to the Figures, and/or one or more individual components or elements of such arrangements and/or one or more process operations associated of such processes, can be employed independently from or together with one or more other components, elements and/or process operations described and illustrated herein. Accordingly, while various arrangements and processes are broadly contemplated, described and illustrated herein, it should be understood that they are provided merely in illustrative and non-restrictive fashion, and furthermore can be regarded as but mere examples of possible working environments in which one or more arrangements or processes may function or operate. [00488] As will be appreciated by one skilled in the art, various aspects may be embodied as a system, method or computer (device) program product. Accordingly, aspects may take the form of an entirely hardware embodiment or an 15694WOO1 (013-0615PCT1) 124 PATENT embodiment including hardware and software that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects may take the form of a computer (device) program product embodied in one or more computer (device) readable storage medium(s) having computer (device) readable program code embodied thereon. [00489] Any combination of one or more non-signal computer (device) readable media may be utilized. The non-signal media may be a storage medium. A storage medium may be, for example, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a storage medium would include the following: a portable computer diskette, a hard disk, a random access memory (RAM), a dynamic random access memory (DRAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. [00490] Program code for carrying out operations may be written in any combination of one or more programming languages. The program code may execute entirely on a single device, partly on a single device, as a stand-alone software package, partly on single device and partly on another device, or entirely on the other device. In some cases, the devices may be connected through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made through other devices (for example, through the Internet using an Internet Service Provider) or through a hard wire connection, such as over a USB connection. For example, a server having a first processor, a network interface, and a storage device for storing code may store the program code for carrying out the operations and provide this code through its network interface via a network to a second device having a second processor for execution of the code on the second device. 15694WOO1 (013-0615PCT1) 125 PATENT [00491] Aspects are described herein with reference to the figures, which illustrate example methods, devices and program products according to various example embodiments. The program instructions may be provided to a processor of a general-purpose computer, special purpose computer, or other programmable data processing device or information handling device to produce a machine, such that the instructions, which execute via a processor of the device implement the functions/acts specified. The program instructions may also be stored in a device readable medium that can direct a device to function in a particular manner, such that the instructions stored in the device readable medium produce an article of manufacture including instructions which implement the function/act specified. The program instructions may also be loaded onto a device to cause a series of operational steps to be performed on the device to produce a device implemented process such that the instructions which execute on the device provide processes for implementing the functions/acts specified. [00492] The units/modules/applications herein may include any processor- based or microprocessor-based system including systems using microcontrollers, reduced instruction set computers (RISC), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), logic circuits, and any other circuit or processor capable of executing the functions described herein. Additionally, or alternatively, the modules/controllers herein may represent circuit modules that may be implemented as hardware with associated instructions (for example, software stored on a tangible and non-transitory computer readable storage medium, such as a computer hard drive, ROM, RAM, or the like) that perform the operations described herein. The above examples are exemplary only, and are thus not intended to limit in any way the definition and/or meaning of the term “controller.” The units/modules/applications herein may execute a set of instructions that are stored in one or more storage elements, in order to process data. The storage elements may also store data or other information as desired or needed. The storage element may be in the form of an information source or a 15694WOO1 (013-0615PCT1) 126 PATENT physical memory element within the modules/controllers herein. The set of instructions may include various commands that instruct the modules/applications herein to perform specific operations such as the methods and processes of the various embodiments of the subject matter described herein. The set of instructions may be in the form of a software program. The software may be in various forms such as system software or application software. Further, the software may be in the form of a collection of separate programs or modules, a program module within a larger program or a portion of a program module. The software also may include modular programming in the form of object-oriented programming. The processing of input data by the processing machine may be in response to user commands, or in response to results of previous processing, or in response to a request made by another processing machine. [00493] It is to be understood that the subject matter described herein is not limited in its application to the details of construction and the arrangement of components set forth in the description herein or illustrated in the drawings hereof. The subject matter described herein is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. [00494] It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings herein without departing from its scope. While the dimensions, types of materials and coatings described herein are intended to define various parameters, they are by no means limiting and are illustrative in nature. Many other embodiments will be apparent to those of skill in the art upon reviewing the above 15694WOO1 (013-0615PCT1) 127 PATENT description. The scope of the embodiments should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein." Moreover, in the following claims, the terms "first," "second," and "third," etc., are used merely as labels, and are not intended to impose numerical requirements on their objects or order of execution on their acts. 15694WOO1 (013-0615PCT1) 128 PATENT

Claims

CLAIMS WHAT IS CLAIMED IS: 1. An implantable medical device (IMD), comprising: a coil configured to receive near field communication (NFC) signals from an external device and to transmit return NFC signals to the external device; a capacitive element having a capacitance configured to vary in response to changes in pressure; and an integrated circuit coupled to the capacitive element, the integrated circuit including: at least one of a processor or circuit configured to: generate pressure data based on the capacitance of the capacitive element; encode the pressure data to form encoded pressure data; and modulate the return NFC signal, to be transmitted by the coil, based on the encoded pressure data.
2. The IMD of claim 1, wherein the at least one of a processor or circuit includes a capacitance to digital (C/D) converter configured to measure the capacitance of the capacitive element and digitally generate the pressure data based on the capacitance of the capacitive element.
3. The IMD of claim 2, wherein the at least one of a processor or circuit is further configured to serially encode the digital pressure data by applying serial encoding.
4. The IMD of claim 3, wherein the serial encoding is one of: Non- Return-to-Zero (NRZ) encoding, Non-Return-to-Zero-Inverted (NRZI) encoding, Return-to-Zero (RZ) encoding, or Manchester encoding. 15694WOO1 (013-0615PCT1) 129 PATENT
5. The IMD of claim 2, wherein the C/D converter comprises a relaxation oscillator, the relaxation oscillator including: a current source configured to charge and discharge the capacitive element; a first oscillator formed by a feedback loop; and a second oscillator configured to measure a duration of charge and discharge cycles of the capacitive element, the duration indicative of the capacitance of the capacitive element.
6. The IMD of claim 1, wherein the at least one of a processor or circuit is further configured to modulate the return NFC signal utilizing load modulation to transition an impedance of the coil between first and second states corresponding to data values in the encoded pressure data.
7. The IMD of claim 6, wherein the transition of the impedance from the first state to the second state corresponds to a logical one in the encoded pressure data and the transition of the impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data.
8. The IMD of claim 1, wherein the at least one of a processor or circuit is further configured to encrypt the encoded pressure data to form encrypted pressure data, the return NFC signal modulated based on the encrypted pressure data.
9. The IMD of claim 1, wherein the coil has a length selected within an interval of from 2 mm to 20mm, a width selected within an interval of from 1 mm to 4mm, and a height selected within an interval of from 0.5mm to 2mm. 15694WOO1 (013-0615PCT1) 130 PATENT
10. The IMD of claim 1, wherein the coil has a maximum length of 10 mm, a maximum width of 2 mm, and a maximum height of 1 mm.
11. The IMD of claim 1, wherein the integrated circuit includes memory configured to store a unique identifier (UID) for the IMD, the integrated circuit configured to combine the UID with the encoded pressure data to modulate the return NFC signal.
12. The IMD of claim 1, wherein the integrated circuit includes a temperature sensor configured to generate temperature data and memory configured to store the temperature data, the integrated circuit configured to combine the temperature data with the encoded pressure data to modulate the return NFC signal.
13. The IMD of claim 1, wherein the IMD is an implantable sensor.
14. The IMD of claim 13, wherein the pressure data is indicative of the pressure in a lumen of a body.
15. A method for generating signals to transmit from an implantable medical device (IMD) to a base unit, comprising: receiving, via a coil communicatively connected to the IMD, near field communication (NFC) signals from the external device; generating, via an integrated circuit coupled to a capacitive element, pressure data based on capacitance of the capacitive element, the capacitance of the capacitive element configured to vary in response to changes in pressure; encoding the pressure data to form encoded pressure data; and modulating a return signal, to be transmitted by the coil, based on the encoded pressure data. 15694WOO1 (013-0615PCT1) 131 PATENT
16. The method of claim 15, wherein the integrated circuit includes a capacitance to digital (C/D) converter, the method further comprising: measuring, using the C/D converter, the capacitance of the capacitive element; and digitally generating the pressure data based on the capacitance of the capacitive element.
17. The method of claim 16, further comprising serially encoding the digital pressure data by applying serial encoding.
18. The method of claim 17, wherein the serial encoding is one of: Non-Return-to-Zero (NRZ) encoding, Non-Return-to-Zero-Inverted (NRZI) encoding, Return-to-Zero (RZ) encoding, or Manchester encoding.
19. The method of claim 16, wherein the C/D converter comprises a relaxation oscillator that includes a current source, a first oscillator, and a second oscillator, the method further comprising: charging and discharging the capacitive element using the current source; forming the first oscillator with a feedback loop; and measuring, using the second oscillator, a duration of charge and discharge cycles of the capacitive element, the duration indicative of the capacitance of the capacitive element.
20. The method of claim 15, wherein the modulating the return signal further comprises modulating the return signal utilizing load modulation to transition an impedance of the coil between first and second states corresponding to data values in the encoded pressure data. 15694WOO1 (013-0615PCT1) 132 PATENT
21. The method of claim 20, wherein the transition of the impedance from the first state to the second state corresponds to a logical one in the encoded pressure data and the transition of the impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data.
22. The method of claim 15, further comprising: encrypting the encoded pressure data to form encrypted pressure data; and modulating the return signal based on the encrypted pressure data.
23. The method of claim 15, wherein the coil has a length selected within an interval of from 2 mm to 20 mm, a width selected within an interval of from 1 mm to 4mm, and a height selected within an interval of from 0.5 mm to 2mm.
24. The method of claim 15, wherein the coil has a maximum length of 10 mm, a maximum width of 2 mm, and a maximum height of 1 mm.
25. The method of claim 15, wherein the integrated circuit includes a memory, the method further comprising: storing a unique identifier (UID) for the IMD in the memory; and combining the UID with the encoded pressure data to modulate the return signal.
26. The method of claim 15, wherein the integrated circuit includes a temperature sensor configured to generate temperature data and memory configured to store the temperature data, the method further comprising combining the temperature data with the encoded pressure data to modulate the return signal. 15694WOO1 (013-0615PCT1) 133 PATENT
27. The method of claim 15, wherein the IMD is an implantable sensor.
28. The method of claim 27, wherein the pressure data is indicative of the changes in the pressure in a lumen of a body.
29. An implantable medical device (IMD), comprising: a coil configured to receive near field communication (NFC) signals from an external device and to transmit return NFC signals to the external device; a capacitive element having a capacitance configured to vary in response to changes in pressure; and an integrated circuit coupled to the capacitive element, the integrated circuit including: a capacitance to digital (C/D) converter configured to measure the capacitance of the capacitive element and generate digital pressure data based on the capacitance of the capacitive element; and at least one of a processor or circuit configured to: modulate the return NFC signal, to be transmitted by the coil, based on the digital pressure data.
30. The IMD of claim 29, wherein the at least one of a processor or circuit is further configured to: encode the digital pressure data to form encoded pressure data; and modulate the return NFC signal, to be transmitted by the coil, based on the encoded pressure data. 15694WOO1 (013-0615PCT1) 134 PATENT
31. The IMD of claim 29, wherein the at least one of a processor or circuit is further configured to serially encode the digital pressure data by applying serial encoding.
32. The IMD of claim 31, wherein the serial encoding is one of: Non- Return-to-Zero (NRZ) encoding, Non-Return-to-Zero-Inverted (NRZI) encoding, Return-to-Zero (RZ) encoding, or Manchester encoding.
33. The IMD of claim 29, wherein the at least one of a processor or circuit is further configured to: encode the digital pressure data to form encoded pressure data; and modulate the return NFC signal utilizing load modulation to transition an impedance of the coil between first and second states corresponding to data values in the encoded pressure data.
34. The IMD of claim 33, wherein the transition of the impedance from the first state to the second state corresponds to a logical one in the encoded pressure data and the transition of the impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data.
35. The IMD of claim 29, wherein the at least one of a processor or circuit is further configured to: encode the digital pressure data to form encoded pressure data; and encrypt the encoded pressure data to form encrypted pressure data, the return NFC signal modulated based on the encrypted pressure data.
36. The IMD of claim 29, wherein the C/D converter comprises a relaxation oscillator, the relaxation oscillator including: a current source configured to charge and discharge the capacitive element; 15694WOO1 (013-0615PCT1) 135 PATENT a first oscillator formed by a feedback loop; and a second oscillator configured to measure a duration of charge and discharge cycles of the capacitive element, the duration indicative of the capacitance of the capacitive element.
37. The IMD of claim 29, wherein the integrated circuit further includes memory configured to store a unique identifier (UID) for the IMD, wherein the at least one of a processor or circuit is further configured to: encode the digital pressure data to form encoded pressure data; and combine the UID with the encoded pressure data to modulate the return NFC signal.
38. The IMD of claim 29, wherein the integrated circuit includes a temperature sensor configured to generate temperature data and memory configured to store the temperature data, wherein the at least one of a processor or circuit is further configured to: encode the digital pressure data to form encoded pressure data; and combine the temperature data with the encoded pressure data to modulate the return NFC signal.
39. The IMD of claim 29, wherein the IMD is an implantable sensor.
40. The IMD of claim 39, wherein the digital pressure data is indicative of a pressure in a lumen of a body.
41. A method for generating signals to transmit from an implantable medical device (IMD) to an external device, comprising: receiving, via a coil communicatively connected to the IMD, near field communication (NFC) signals from the external device; 15694WOO1 (013-0615PCT1) 136 PATENT measuring, via a capacitance to digital (C/D) converter, capacitance of a capacitance element, the C/D converter included within an integrated circuit coupled to the capacitive element, the capacitive element having the capacitance configured to vary in response to changes in pressure; generating digital pressure data, via the C/D converter, based on the capacitance of the capacitive element; and modulating a return signal, using at least one of a processor or circuit included within the integrated circuit, based on the digital pressure data.
42. The method of claim 41, further comprising: encoding the digital pressure data to form encoded pressure data; and modulating the return signal, to be transmitted by the coil, based on the encoded pressure data.
43. The method of claim 41, further comprising serially encoding the digital pressure data by applying serial encoding.
44. The method of claim 43, wherein the serial encoding is one of: Non-Return-to-Zero (NRZ) encoding, Non-Return-to-Zero-Inverted (NRZI) encoding, Return-to-Zero (RZ) encoding, or Manchester encoding.
45. The method of claim 41, further comprising: encoding the digital pressure data to form encoded pressure data; and modulating the return signal utilizing load modulation to transition an impedance of the coil between first and second states corresponding to data values in the encoded pressure data.
46. The method of claim 45, wherein the transition of the impedance from the first state to the second state corresponds to a logical one in the 15694WOO1 (013-0615PCT1) 137 PATENT encoded pressure data and the transition of the impedance from the second state to the first state corresponds to a logical zero in the encoded pressure data.
47. The method of claim 41, further comprising: encoding the digital pressure data to form encoded pressure data; encrypting the encoded pressure data to form encrypted pressure data; and modulating the return signal based on the encrypted pressure data.
48. The method of claim 41, wherein the C/D converter comprises a relaxation oscillator including a current source, a first oscillator, and a second oscillator, the method further comprising: charging and discharging the capacitive element using the current source; forming the first oscillator with a feedback loop; and measuring, using the second oscillator, a duration of charge and discharge cycles of the capacitive element, the duration indicative of the capacitance of the capacitive element.
49. The method of claim 41, further comprising: storing a unique identifier (UID) for the IMD in a memory within or communicatively connected to the integrated circuit; encoding the digital pressure data to form encoded pressure data; and combining the UID with the encoded pressure data to modulate the return signal.
50. The method of claim 41, further comprising: encoding the digital pressure data to form encoded pressure data; generating temperature data with a temperature sensor included within the integrated circuit; and 15694WOO1 (013-0615PCT1) 138 PATENT combining the temperature data with the encoded pressure data to modulate the return signal.
51. The method of claim 41, wherein the IMD is an implantable sensor.
52. The method of claim 51, wherein the digital pressure data is indicative of the pressure in a lumen of a body. 15694WOO1 (013-0615PCT1) 139 PATENT
PCT/US2025/022515 2024-04-04 2025-04-01 Method and device for cardiac pressure sensing using an active implantable device and near field communication Pending WO2025212628A1 (en)

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Citations (89)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6480733B1 (en) 1999-11-10 2002-11-12 Pacesetter, Inc. Method for monitoring heart failure
US6572557B2 (en) 2000-05-09 2003-06-03 Pacesetter, Inc. System and method for monitoring progression of cardiac disease state using physiologic sensors
US6645153B2 (en) 2002-02-07 2003-11-11 Pacesetter, Inc. System and method for evaluating risk of mortality due to congestive heart failure using physiologic sensors
US7147604B1 (en) 2002-08-07 2006-12-12 Cardiomems, Inc. High Q factor sensor
US20060287602A1 (en) 2005-06-21 2006-12-21 Cardiomems, Inc. Implantable wireless sensor for in vivo pressure measurement
US20070158769A1 (en) 2005-10-14 2007-07-12 Cardiomems, Inc. Integrated CMOS-MEMS technology for wired implantable sensors
US7245117B1 (en) 2004-11-01 2007-07-17 Cardiomems, Inc. Communicating with implanted wireless sensor
US20070199385A1 (en) 2005-11-18 2007-08-30 Cardiomems, Inc. Capacitor electrode formed on surface of integrated circuit chip
US7272443B2 (en) 2004-03-26 2007-09-18 Pacesetter, Inc. System and method for predicting a heart condition based on impedance values using an implantable medical device
US7308309B1 (en) 2005-01-11 2007-12-11 Pacesetter, Inc. Diagnosing cardiac health utilizing parameter trend analysis
US7481771B2 (en) 2002-01-22 2009-01-27 Cardiomems, Inc. Implantable wireless sensor for pressure measurement within the heart
US7492144B2 (en) 2005-09-06 2009-02-17 Cardiomems, Inc. Preventing false locks in a system that communicates with an implanted wireless sensor
US7618363B2 (en) 2002-08-06 2009-11-17 Cardiomems, Inc. Hydraulically actuated artificial muscle for ventricular assist
US7621036B2 (en) 2005-06-21 2009-11-24 Cardiomems, Inc. Method of manufacturing implantable wireless sensor for in vivo pressure measurement
US7667547B2 (en) 2007-08-22 2010-02-23 Cardiomems, Inc. Loosely-coupled oscillator
US7699059B2 (en) 2002-01-22 2010-04-20 Cardiomems, Inc. Implantable wireless sensor
US7748277B2 (en) 2005-10-19 2010-07-06 Cardiomems, Inc. Hermetic chamber with electrical feedthroughs
US7812416B2 (en) 2006-05-22 2010-10-12 Cardiomems, Inc. Methods and apparatus having an integrated circuit attached to fused silica
US7829363B2 (en) 2006-05-22 2010-11-09 Cardiomems, Inc. Method and apparatus for microjoining dissimilar materials
US7854172B2 (en) 2005-02-10 2010-12-21 Cardiomems, Inc. Hermetic chamber with electrical feedthroughs
US7908018B2 (en) 2006-09-06 2011-03-15 Cardiomems, Inc. Flexible electrode
US7909770B2 (en) 2006-07-05 2011-03-22 Cardiomems, Inc. Method for using a wireless pressure sensor to monitor pressure inside the human heart
US7966886B2 (en) 2006-10-20 2011-06-28 Cardiomems, Inc. Method and apparatus for measuring pressure inside a fluid system
US8026729B2 (en) 2003-09-16 2011-09-27 Cardiomems, Inc. System and apparatus for in-vivo assessment of relative position of an implant
US20120016207A1 (en) 2005-04-12 2012-01-19 Cardiomems Electromagnetically coupled hermetic chamber
US8159348B2 (en) 2008-02-29 2012-04-17 Cardiomems, Inc. Communication system with antenna box amplifier
US8264240B2 (en) 2008-07-20 2012-09-11 Cardiomems, Inc. Physical property sensor with active electronic circuit and wireless power and data transmission
US8278941B2 (en) 2003-09-16 2012-10-02 Cardiomems, Inc. Strain monitoring system and apparatus
US8355777B2 (en) 2005-03-03 2013-01-15 Cardiomems, Inc. Apparatus and method for sensor deployment and fixation
US8391980B2 (en) 2009-07-07 2013-03-05 Pacesetter, Inc. Method and system for identifying a potential lead failure in an implantable medical device
US20130245469A1 (en) 2012-03-19 2013-09-19 Cardiomems, Inc. Pulmonary Arterial Hemodynamic Monitoring for Chronic Obstructive Pulmonary Disease Assessment and Treatment
US20130296721A1 (en) 2009-01-27 2013-11-07 Cardiomems, Inc. Hypertension System And Method
US8665086B2 (en) 2006-09-08 2014-03-04 Cardiomems, Inc. Physiological data acquisition and management system for use with an implanted wireless sensor
US8669770B2 (en) 2009-11-16 2014-03-11 Cardiomems, Inc. Selectively actuating wireless, passive implantable sensor
US20140084943A1 (en) 2012-09-21 2014-03-27 Cardiomems, Inc. Strain monitoring system and apparatus
US20140088994A1 (en) 2012-09-21 2014-03-27 CardioMEMS, Inc Method and system for trend-based patient management
US20140100627A1 (en) * 2012-10-08 2014-04-10 Pacesetter, Inc. Leadless intra-cardiac medical device with integrated l-c resonant circuit pressure sensor
US20140155769A1 (en) 2012-11-21 2014-06-05 Cardiomems, Inc. Devices, Systems, and Methods for Pulmonary Arterial Hypertension (PAH) Assessment and Treatment
US8831747B1 (en) 2013-11-19 2014-09-09 Pacesetter, Inc. Leadless neurostimulation device and method including the same
US20140275861A1 (en) 2013-03-15 2014-09-18 Cardiomems, Inc. Ambulatory sensing system and associated methods
US20140288085A1 (en) 2013-03-15 2014-09-25 Cardiomems, Inc. Methods for the Treatment of Cardiovascular Conditions
US20140288459A1 (en) 2013-03-25 2014-09-25 Cardiomems, Inc. Ventricular shunt system and method
US8870787B2 (en) 2003-09-16 2014-10-28 Cardiomems, Inc. Ventricular shunt system and method
US20140330143A1 (en) 2013-05-03 2014-11-06 Cardiomems, Inc. Method and system for treating cardiovascular disease
US20150133796A1 (en) 2010-08-06 2015-05-14 Cardiomems, Inc. Systems and methods for using physiological information
US9044610B2 (en) 2013-03-15 2015-06-02 Pacesetter, Inc. Systems and methods for providing a distributed virtual stimulation cathode for use with an implantable neurostimulation system
US9078563B2 (en) 2005-06-21 2015-07-14 St. Jude Medical Luxembourg Holdings II S.à.r.l. Method of manufacturing implantable wireless sensor for in vivo pressure measurement
US9216285B1 (en) 2014-12-18 2015-12-22 Pacesetter, Inc. Leadless implantable medical device having removable and fixed components
US9232485B2 (en) 2013-08-23 2016-01-05 Pacesetter, Inc. System and method for selectively communicating with an implantable medical device
US9265428B2 (en) 2003-09-16 2016-02-23 St. Jude Medical Luxembourg Holdings Ii S.A.R.L. (“Sjm Lux Ii”) Implantable wireless sensor
US9288614B1 (en) 2015-03-03 2016-03-15 Pacesetter, Inc. Systems and methods for initiating a communication link between an implantable medical device and an external device
US9333351B2 (en) 2013-12-16 2016-05-10 Pacesetter, Inc. Neurostimulation method and system to treat apnea
US9792469B1 (en) 2016-10-17 2017-10-17 Pacesetter, Inc. Wireless physical property sensor with digital communications
US20180007139A1 (en) 2014-05-21 2018-01-04 Abbott Diabetes Care Inc. Management of multiple devices within an analyte monitoring environment
US9907470B2 (en) 2005-02-08 2018-03-06 Abbott Diabetes Care Inc. Analyte meter including an RFID reader
US9949660B2 (en) 2016-03-29 2018-04-24 Pacesetter, Inc. Method and system to discriminate rhythm patterns in cardiac activity
US9955289B1 (en) 2016-09-14 2018-04-24 Pacesetter, Inc. Systems and methods for implantable medical devices including near field communications
US20180199813A1 (en) 2015-05-14 2018-07-19 Abbott Diabetes Care Inc. Systems, devices, and methods for monitoring medical devices
US10290208B2 (en) 2012-12-20 2019-05-14 Abbott Diabetes Care Inc. Methods for enabling a disabled capability of a medical device
US10361574B2 (en) 2013-11-05 2019-07-23 Abbott Diabetes Care Inc. Systems, devices, and methods for control of a power supply connection
US20190354674A1 (en) 2013-12-27 2019-11-21 Abbott Diabetes Care Inc. Application interface and display control in an analyte monitoring environment
US10488362B2 (en) 2014-10-24 2019-11-26 Abbott Laboratories Paper substrate diagnostic apparatus and related methods and systems
US20200100676A1 (en) 2009-08-31 2020-04-02 Abbott Diabetes Care Inc. Medical Devices and Methods
US20200196867A1 (en) * 2018-12-20 2020-06-25 Pacesetter, Inc. Method and apparatus for a burst operation pressure sensor
US10722704B2 (en) 2018-05-07 2020-07-28 Pacesetter, Inc. Implantable medical systems and methods including pulse generators and leads
US10742269B2 (en) 2017-03-02 2020-08-11 Abbott Diabetes Care Inc. Systems, devices, and methods utilizing secondary communication systems
US10765860B2 (en) 2018-05-07 2020-09-08 Pacesetter, Inc. Subcutaneous implantation medical device with multiple parasternal-anterior electrodes
US20210020294A1 (en) 2019-07-18 2021-01-21 Pacesetter, Inc. Methods, devices and systems for holistic integrated healthcare patient management
US11045643B2 (en) 2018-05-07 2021-06-29 Pacesetter, Inc. Single-site implantation methods for medical devices having multiple leads
US20210330239A1 (en) 2020-04-22 2021-10-28 Pacesetter, Inc. Method and system for adaptive-sensing of electrical cardiac signals
US11219379B2 (en) 2013-01-31 2022-01-11 Pacesetter, Inc. Wireless MEMS left atrial pressure sensor
MX2021012625A (en) 2019-04-18 2022-01-24 Abbott Diabetes Care Inc SYSTEMS, DEVICES AND METHODS FOR HANDLING WIRELESS COMMUNICATIONS IN AN ANALYTE MONITORING ENVIRONMENT.
US20220070666A1 (en) 2020-08-31 2022-03-03 Abbott Diabetes Care Inc. Secured communications in medical monitoring systems
US20220116395A1 (en) 2013-12-27 2022-04-14 Abbott Diabetes Care Inc. Systems, devices, and methods for authentication in an analyte monitoring environment
US20220167885A1 (en) 2017-06-29 2022-06-02 Abbott Diabetes Care Inc. Systems, devices, and methods for establishing and/or maintaining synchronization between entities in an analyte monitoring environment
US20220240819A1 (en) 2021-01-29 2022-08-04 Abbott Diabetes Care Inc. Third party analyte monitoring
US20220369926A1 (en) 2019-10-28 2022-11-24 Abbott Diabetes Care Inc. Systems, devices, and methods for sensor communications
US20230000350A1 (en) 2017-02-15 2023-01-05 Abbott Diabetes Care Inc. Systems, devices, and methods for integration of an analyte data reader and medication delivery device
US20230027588A1 (en) 2021-07-21 2023-01-26 Abbott Diabetes Care Inc. Over-the-Air Programming of Sensing Devices
US11571149B1 (en) 2013-04-30 2023-02-07 Abbott Diabetes Care Inc. Systems, devices, and methods for energy efficient electrical device activation
US20230096239A1 (en) 2021-09-29 2023-03-30 Abbott Diabetes Care Inc. Mobile Application Updates for Analyte Data Receiving Devices
US20230109023A1 (en) 2021-10-05 2023-04-06 Tc1 Llc System and method for intra-body communication of sensed physiologic data
US20230157590A1 (en) 2018-06-07 2023-05-25 Abbott Diabetes Care Inc. Focused sterilization and sterilized subassemblies for analyte monitoring systems
US20230248272A1 (en) 2022-02-04 2023-08-10 Abbott Diabetes Care Inc. Systems, devices, and methods for an analyte sensor
US11759623B2 (en) 2020-01-07 2023-09-19 Pacesetter, Inc. Implantable medical devices including low frequency and high frequency clocks and related methods
US20230389838A1 (en) 2017-08-18 2023-12-07 Abbott Diabetes Care Inc. Systems, devices, and methods related to the individualized calibration and/or manufacturing of medical devices
US20230404441A1 (en) 2022-04-26 2023-12-21 Abbott Diabetes Care Inc. Systems, devices, and methods for meal-related analyte response monitoring
US20240053324A1 (en) 2016-12-20 2024-02-15 Abbott Diabetes Care Inc. Systems, devices, and methods for wireless communications in analyte monitoring systems
US20240065586A1 (en) 2022-08-31 2024-02-29 Abbott Diabetes Care Inc. System, apparatus, and devices for analyte monitoring

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8996121B2 (en) * 2009-07-10 2015-03-31 Cochlear Limited Varying the effective coil area for an inductive transcutaneous power link
US10881869B2 (en) * 2016-11-21 2021-01-05 Cardiac Pacemakers, Inc. Wireless re-charge of an implantable medical device

Patent Citations (98)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6480733B1 (en) 1999-11-10 2002-11-12 Pacesetter, Inc. Method for monitoring heart failure
US6572557B2 (en) 2000-05-09 2003-06-03 Pacesetter, Inc. System and method for monitoring progression of cardiac disease state using physiologic sensors
US7699059B2 (en) 2002-01-22 2010-04-20 Cardiomems, Inc. Implantable wireless sensor
US7481771B2 (en) 2002-01-22 2009-01-27 Cardiomems, Inc. Implantable wireless sensor for pressure measurement within the heart
US6645153B2 (en) 2002-02-07 2003-11-11 Pacesetter, Inc. System and method for evaluating risk of mortality due to congestive heart failure using physiologic sensors
US7618363B2 (en) 2002-08-06 2009-11-17 Cardiomems, Inc. Hydraulically actuated artificial muscle for ventricular assist
US7147604B1 (en) 2002-08-07 2006-12-12 Cardiomems, Inc. High Q factor sensor
US8278941B2 (en) 2003-09-16 2012-10-02 Cardiomems, Inc. Strain monitoring system and apparatus
US9265428B2 (en) 2003-09-16 2016-02-23 St. Jude Medical Luxembourg Holdings Ii S.A.R.L. (“Sjm Lux Ii”) Implantable wireless sensor
US8026729B2 (en) 2003-09-16 2011-09-27 Cardiomems, Inc. System and apparatus for in-vivo assessment of relative position of an implant
US8896324B2 (en) 2003-09-16 2014-11-25 Cardiomems, Inc. System, apparatus, and method for in-vivo assessment of relative position of an implant
US8870787B2 (en) 2003-09-16 2014-10-28 Cardiomems, Inc. Ventricular shunt system and method
US7272443B2 (en) 2004-03-26 2007-09-18 Pacesetter, Inc. System and method for predicting a heart condition based on impedance values using an implantable medical device
US8237451B2 (en) 2004-11-01 2012-08-07 Cardiomems, Inc. Communicating with an implanted wireless sensor
US7245117B1 (en) 2004-11-01 2007-07-17 Cardiomems, Inc. Communicating with implanted wireless sensor
US7308309B1 (en) 2005-01-11 2007-12-11 Pacesetter, Inc. Diagnosing cardiac health utilizing parameter trend analysis
US9907470B2 (en) 2005-02-08 2018-03-06 Abbott Diabetes Care Inc. Analyte meter including an RFID reader
US7854172B2 (en) 2005-02-10 2010-12-21 Cardiomems, Inc. Hermetic chamber with electrical feedthroughs
US8355777B2 (en) 2005-03-03 2013-01-15 Cardiomems, Inc. Apparatus and method for sensor deployment and fixation
US20120016207A1 (en) 2005-04-12 2012-01-19 Cardiomems Electromagnetically coupled hermetic chamber
US9078563B2 (en) 2005-06-21 2015-07-14 St. Jude Medical Luxembourg Holdings II S.à.r.l. Method of manufacturing implantable wireless sensor for in vivo pressure measurement
US11033192B2 (en) 2005-06-21 2021-06-15 St. Jude Medical Luxembourg Holdings Ii S.A.R.L. (“Sjm Lux 11”) Wireless sensor for measuring pressure
US7621036B2 (en) 2005-06-21 2009-11-24 Cardiomems, Inc. Method of manufacturing implantable wireless sensor for in vivo pressure measurement
US20060287602A1 (en) 2005-06-21 2006-12-21 Cardiomems, Inc. Implantable wireless sensor for in vivo pressure measurement
US10143388B2 (en) 2005-06-21 2018-12-04 St, Jude Medical Luxembourg Holdings II S.A.R.L. (“SJM LUX II”) Method of manufacturing implantable wireless sensor for pressure measurement
US20220079456A1 (en) 2005-06-21 2022-03-17 St. Jude Medical Luxembourg Holdings Ii S.A.R.L. ("Sjm Lux 11") System and method for calculating a lumen pressure utilizing sensor calibration parameters
US7710103B2 (en) 2005-09-06 2010-05-04 Cardiomems, Inc. Preventing false locks in a system that communicates with an implanted wireless sensor
US7492144B2 (en) 2005-09-06 2009-02-17 Cardiomems, Inc. Preventing false locks in a system that communicates with an implanted wireless sensor
US20070158769A1 (en) 2005-10-14 2007-07-12 Cardiomems, Inc. Integrated CMOS-MEMS technology for wired implantable sensors
US7748277B2 (en) 2005-10-19 2010-07-06 Cardiomems, Inc. Hermetic chamber with electrical feedthroughs
US20070199385A1 (en) 2005-11-18 2007-08-30 Cardiomems, Inc. Capacitor electrode formed on surface of integrated circuit chip
US7829363B2 (en) 2006-05-22 2010-11-09 Cardiomems, Inc. Method and apparatus for microjoining dissimilar materials
US7812416B2 (en) 2006-05-22 2010-10-12 Cardiomems, Inc. Methods and apparatus having an integrated circuit attached to fused silica
US7909770B2 (en) 2006-07-05 2011-03-22 Cardiomems, Inc. Method for using a wireless pressure sensor to monitor pressure inside the human heart
US7908018B2 (en) 2006-09-06 2011-03-15 Cardiomems, Inc. Flexible electrode
US8665086B2 (en) 2006-09-08 2014-03-04 Cardiomems, Inc. Physiological data acquisition and management system for use with an implanted wireless sensor
US7966886B2 (en) 2006-10-20 2011-06-28 Cardiomems, Inc. Method and apparatus for measuring pressure inside a fluid system
US7667547B2 (en) 2007-08-22 2010-02-23 Cardiomems, Inc. Loosely-coupled oscillator
US8159348B2 (en) 2008-02-29 2012-04-17 Cardiomems, Inc. Communication system with antenna box amplifier
US8264240B2 (en) 2008-07-20 2012-09-11 Cardiomems, Inc. Physical property sensor with active electronic circuit and wireless power and data transmission
US9653926B2 (en) 2008-07-20 2017-05-16 St. Jude Medical Luxenbourg Holdings II S. A. R. L (“SJM LUX II”) Physical property sensor with active electronic circuit and wireless power and data transmission
US20130296721A1 (en) 2009-01-27 2013-11-07 Cardiomems, Inc. Hypertension System And Method
US8391980B2 (en) 2009-07-07 2013-03-05 Pacesetter, Inc. Method and system for identifying a potential lead failure in an implantable medical device
US20200100676A1 (en) 2009-08-31 2020-04-02 Abbott Diabetes Care Inc. Medical Devices and Methods
US8669770B2 (en) 2009-11-16 2014-03-11 Cardiomems, Inc. Selectively actuating wireless, passive implantable sensor
US20150133796A1 (en) 2010-08-06 2015-05-14 Cardiomems, Inc. Systems and methods for using physiological information
US20130245469A1 (en) 2012-03-19 2013-09-19 Cardiomems, Inc. Pulmonary Arterial Hemodynamic Monitoring for Chronic Obstructive Pulmonary Disease Assessment and Treatment
US20140088994A1 (en) 2012-09-21 2014-03-27 CardioMEMS, Inc Method and system for trend-based patient management
US20140084943A1 (en) 2012-09-21 2014-03-27 Cardiomems, Inc. Strain monitoring system and apparatus
US20140100627A1 (en) * 2012-10-08 2014-04-10 Pacesetter, Inc. Leadless intra-cardiac medical device with integrated l-c resonant circuit pressure sensor
US20140155769A1 (en) 2012-11-21 2014-06-05 Cardiomems, Inc. Devices, Systems, and Methods for Pulmonary Arterial Hypertension (PAH) Assessment and Treatment
US11832920B2 (en) 2012-11-21 2023-12-05 St. Jude Medical Luxembourg Holdings Ii S.A.R.L. (“Sjm Lux Ii”) Devices, systems, and methods for pulmonary arterial hypertension (PAH) assessment and treatment
US10290208B2 (en) 2012-12-20 2019-05-14 Abbott Diabetes Care Inc. Methods for enabling a disabled capability of a medical device
US11219379B2 (en) 2013-01-31 2022-01-11 Pacesetter, Inc. Wireless MEMS left atrial pressure sensor
US20140275861A1 (en) 2013-03-15 2014-09-18 Cardiomems, Inc. Ambulatory sensing system and associated methods
US20140288085A1 (en) 2013-03-15 2014-09-25 Cardiomems, Inc. Methods for the Treatment of Cardiovascular Conditions
US9044610B2 (en) 2013-03-15 2015-06-02 Pacesetter, Inc. Systems and methods for providing a distributed virtual stimulation cathode for use with an implantable neurostimulation system
US20140288459A1 (en) 2013-03-25 2014-09-25 Cardiomems, Inc. Ventricular shunt system and method
US11571149B1 (en) 2013-04-30 2023-02-07 Abbott Diabetes Care Inc. Systems, devices, and methods for energy efficient electrical device activation
US20140330143A1 (en) 2013-05-03 2014-11-06 Cardiomems, Inc. Method and system for treating cardiovascular disease
US9232485B2 (en) 2013-08-23 2016-01-05 Pacesetter, Inc. System and method for selectively communicating with an implantable medical device
US10361574B2 (en) 2013-11-05 2019-07-23 Abbott Diabetes Care Inc. Systems, devices, and methods for control of a power supply connection
US8831747B1 (en) 2013-11-19 2014-09-09 Pacesetter, Inc. Leadless neurostimulation device and method including the same
US9333351B2 (en) 2013-12-16 2016-05-10 Pacesetter, Inc. Neurostimulation method and system to treat apnea
US20190354674A1 (en) 2013-12-27 2019-11-21 Abbott Diabetes Care Inc. Application interface and display control in an analyte monitoring environment
US20220116395A1 (en) 2013-12-27 2022-04-14 Abbott Diabetes Care Inc. Systems, devices, and methods for authentication in an analyte monitoring environment
US20180007139A1 (en) 2014-05-21 2018-01-04 Abbott Diabetes Care Inc. Management of multiple devices within an analyte monitoring environment
US10488362B2 (en) 2014-10-24 2019-11-26 Abbott Laboratories Paper substrate diagnostic apparatus and related methods and systems
US9216285B1 (en) 2014-12-18 2015-12-22 Pacesetter, Inc. Leadless implantable medical device having removable and fixed components
US9288614B1 (en) 2015-03-03 2016-03-15 Pacesetter, Inc. Systems and methods for initiating a communication link between an implantable medical device and an external device
US20180199813A1 (en) 2015-05-14 2018-07-19 Abbott Diabetes Care Inc. Systems, devices, and methods for monitoring medical devices
US9949660B2 (en) 2016-03-29 2018-04-24 Pacesetter, Inc. Method and system to discriminate rhythm patterns in cardiac activity
US9955289B1 (en) 2016-09-14 2018-04-24 Pacesetter, Inc. Systems and methods for implantable medical devices including near field communications
US9792469B1 (en) 2016-10-17 2017-10-17 Pacesetter, Inc. Wireless physical property sensor with digital communications
US20240053324A1 (en) 2016-12-20 2024-02-15 Abbott Diabetes Care Inc. Systems, devices, and methods for wireless communications in analyte monitoring systems
US20230000350A1 (en) 2017-02-15 2023-01-05 Abbott Diabetes Care Inc. Systems, devices, and methods for integration of an analyte data reader and medication delivery device
US10742269B2 (en) 2017-03-02 2020-08-11 Abbott Diabetes Care Inc. Systems, devices, and methods utilizing secondary communication systems
US20220167885A1 (en) 2017-06-29 2022-06-02 Abbott Diabetes Care Inc. Systems, devices, and methods for establishing and/or maintaining synchronization between entities in an analyte monitoring environment
US20230389838A1 (en) 2017-08-18 2023-12-07 Abbott Diabetes Care Inc. Systems, devices, and methods related to the individualized calibration and/or manufacturing of medical devices
US10765860B2 (en) 2018-05-07 2020-09-08 Pacesetter, Inc. Subcutaneous implantation medical device with multiple parasternal-anterior electrodes
US10722704B2 (en) 2018-05-07 2020-07-28 Pacesetter, Inc. Implantable medical systems and methods including pulse generators and leads
US11045643B2 (en) 2018-05-07 2021-06-29 Pacesetter, Inc. Single-site implantation methods for medical devices having multiple leads
US20230157590A1 (en) 2018-06-07 2023-05-25 Abbott Diabetes Care Inc. Focused sterilization and sterilized subassemblies for analyte monitoring systems
US11330981B2 (en) 2018-12-20 2022-05-17 Pacesetter, Inc. Method and apparatus for a burst operation pressure sensor
US20200196867A1 (en) * 2018-12-20 2020-06-25 Pacesetter, Inc. Method and apparatus for a burst operation pressure sensor
MX2021012625A (en) 2019-04-18 2022-01-24 Abbott Diabetes Care Inc SYSTEMS, DEVICES AND METHODS FOR HANDLING WIRELESS COMMUNICATIONS IN AN ANALYTE MONITORING ENVIRONMENT.
US20210020294A1 (en) 2019-07-18 2021-01-21 Pacesetter, Inc. Methods, devices and systems for holistic integrated healthcare patient management
US20220369926A1 (en) 2019-10-28 2022-11-24 Abbott Diabetes Care Inc. Systems, devices, and methods for sensor communications
US11759623B2 (en) 2020-01-07 2023-09-19 Pacesetter, Inc. Implantable medical devices including low frequency and high frequency clocks and related methods
US20210330239A1 (en) 2020-04-22 2021-10-28 Pacesetter, Inc. Method and system for adaptive-sensing of electrical cardiac signals
US20220070666A1 (en) 2020-08-31 2022-03-03 Abbott Diabetes Care Inc. Secured communications in medical monitoring systems
US20220240819A1 (en) 2021-01-29 2022-08-04 Abbott Diabetes Care Inc. Third party analyte monitoring
US20230027588A1 (en) 2021-07-21 2023-01-26 Abbott Diabetes Care Inc. Over-the-Air Programming of Sensing Devices
US20230096239A1 (en) 2021-09-29 2023-03-30 Abbott Diabetes Care Inc. Mobile Application Updates for Analyte Data Receiving Devices
US20230109023A1 (en) 2021-10-05 2023-04-06 Tc1 Llc System and method for intra-body communication of sensed physiologic data
US20230248272A1 (en) 2022-02-04 2023-08-10 Abbott Diabetes Care Inc. Systems, devices, and methods for an analyte sensor
US20230404441A1 (en) 2022-04-26 2023-12-21 Abbott Diabetes Care Inc. Systems, devices, and methods for meal-related analyte response monitoring
US20240065586A1 (en) 2022-08-31 2024-02-29 Abbott Diabetes Care Inc. System, apparatus, and devices for analyte monitoring

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