WO2025068826A1

WO2025068826A1 - Implant with sensor integrated with induction coil

Info

Publication number: WO2025068826A1
Application number: PCT/IB2024/059083
Authority: WO
Inventors: Oliver John RIDLER
Original assignee: Cochlear Ltd
Current assignee: Cochlear Ltd
Priority date: 2023-09-27
Filing date: 2024-09-18
Publication date: 2025-04-03
Anticipated expiration: 2026-03-27

Abstract

An apparatus includes at least one housing having a first housing portion and a second housing portion, the at least one housing configured to be implanted beneath a skin of a recipient's body. The apparatus further includes an electrically conductive coil within the first housing portion and configured to transcutaneously and wirelessly receive power from an external device outside the skin. The apparatus further includes at least one sensor at least partially on or within the first housing portion. The at least one sensor is configured to receive sound and to generate electrical signals indicative of the sound. The apparatus further includes circuitry within the second housing portion. The circuitry is configured to receive the power from the coil, to receive the electrical signals from the at least one sensor, and to generate stimulation signals indicative of the sound.

Description

IMPLANT WITH SENSOR INTEGRATED WITH INDUCTION COIL

BACKGROUND

Field

[0001] The present application relates generally to systems configured to be implanted on or within a recipient’s body with induction coils for wirelessly communicating data to and/or from a device external to the recipient’s body.

Description of the Related Art

[0002] Medical devices have provided a wide range of therapeutic benefits to recipients over recent decades. Medical devices can include internal or implantable components/de vices, external or wearable components/devices, or combinations thereof (e.g., a device having an external component communicating with an implantable component). Medical devices, such as traditional hearing aids, partially or fully-implantable hearing prostheses (e.g., bone conduction devices, mechanical stimulators, cochlear implants, etc.), pacemakers, defibrillators, functional electrical stimulation devices, and other medical devices, have been successful in performing lifesaving and/or lifestyle enhancement functions and/or recipient monitoring for a number of years.

[0003] The types of medical devices and the ranges of functions performed thereby have increased over the years. For example, many medical devices, sometimes referred to as “implantable medical devices,” now often include one or more instruments, apparatus, sensors, processors, controllers or other functional mechanical or electrical components that are permanently or temporarily implanted in a recipient. These functional devices are typically used to diagnose, prevent, monitor, treat, or manage a disease/injury or symptom thereof, or to investigate, replace or modify the anatomy or a physiological process. Many of these functional devices utilize power and/or data received from external devices that are part of, or operate in conjunction with, implantable components.

SUMMARY

[0004] In one aspect disclosed herein, an apparatus comprises at least one housing configured to be implanted beneath a skin of a recipient’s body. The at least one housing comprises a first housing portion and a second housing portion. The apparatus further comprises an electrically conductive coil within the first housing portion and configured to transcutaneously and wirelessly receive power from an external device outside the skin. The apparatus further comprises at least one sensor at least partially on or within the first housing portion. The at least one sensor is configured to receive sound and to generate electrical signals indicative of the sound. The apparatus further comprises circuitry within the second housing portion. The circuitry is configured to receive the power from the coil, to receive the electrical signals from the at least one sensor, and to generate stimulation signals indicative of the sound.

[0005] In another aspect disclosed herein, an apparatus comprises an electrically insulative body configured to be implanted on or within a recipient. The apparatus further comprises a substantially planar antenna coil within the body. The antenna coil is configured to wirelessly receive electrical signals from a signal source through tissue between the antenna coil and the signal source. The apparatus further comprises at least one active pressure sensing assembly comprising a chamber comprising a flexible and resilient wall portion and gas within the chamber and a gas pressure sensor in fluidic communication with the gas within the chamber. The chamber is positioned between the antenna coil and the tissue, and the wall portion is configured to flex in response to acoustic pressure waves propagating through the tissue and impinging the chamber such that the acoustic pressure waves propagate through the gas. The gas pressure sensor is configured to receive the acoustic pressure waves propagating through the gas and to generate signals indicative of the acoustic pressure waves.

[0006] In another aspect disclosed herein, a method comprises providing a substantially planar inductive coil and providing at least one pressure sensitive sensor configured to receive sound and to generate electrical signals indicative of the sound. The method further comprises placing the at least one pressure sensitive sensor above, below, or adjacent to the inductive coil. The method further comprises hermetically sealing at least a portion of the inductive coil and the at least one pressure sensitive sensor within an electrically insulating dielectric casing.

[0007] In another aspect disclosed herein, a system comprises at least one implantable component configured to be implanted beneath a skin layer of a recipient’s body. The at least one implantable component comprises a first housing portion and a second housing portion. The system further comprises at least one external component configured to be worn above the skin layer of the recipient’s body. The system further comprises a wireless communication component within the first housing portion and configured to communicate wirelessly with the at least one external component while the at least one external component is worn above the skin layer of the recipient’s body. The system further comprises a sensor component at least partially on or within the first housing portion. The sensor component has a first sensing capability to stimuli while the at least one external component is not worn above the skin layer of the recipient’s body and has a second sensing capability to the stimuli while the at least one external component is worn above the skin layer of the recipient’s body. The second sensing capability is lower than the first sensing capability. The system further comprises circuitry within the second housing portion. The circuitry is configured to receive one or both of input from the wireless communication component and signals from the sensor component.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Implementations are described herein in conjunction with the accompanying drawings, in which:

[0009] FIG. 1A is a perspective view of an example cochlear implant auditory prosthesis implanted in a recipient in accordance with certain implementations described herein;

[0010] FIG. IB is a perspective view of an example fully implantable middle ear implant auditory prosthesis implanted in a recipient in accordance with certain implementations described herein;

[0011] FIG. 2A schematically illustrates a top view of an example apparatus in accordance with certain implementations described herein;

[0012] FIG. 2B schematically illustrates a cross-sectional view of the example apparatus of FIG. 2A in accordance with certain implementations described herein and a device 400 external to the recipient’s body;

[0013] FIGs. 2C-2E schematically illustrate top views of other example apparatus in accordance with certain implementations described herein;

[0014] FIG. 3A schematically illustrates a cross-sectional view of another example apparatus in accordance with certain implementations described herein and FIGs. 3B and 3C schematically illustrate top views of two example apparatus in accordance with certain implementations described herein; and [0015] FIG. 4 is a flow diagram of an example method in accordance with certain implementations described herein.

DETAILED DESCRIPTION

[0016] Certain implementations described herein provide an implant having a pressure sensing device (e.g., microphone) in proximity to (e.g., above; below; alongside) a communication coil of the implant. In contrast to other implants with pressure sensing devices in a pendant on a lead or inside the circuitry housing, an implant as described herein provides benefits of reduced cost, reduced size, and/or reduced surgical complexity. The pressure sensing device can include a gas-filled bladder that extends over the communication coil and is in fluidic communication with a gas pressure sensor. Sound incident on the bladder generate acoustic pressure waves in the gas and the sensor is responsive to the acoustic pressure waves by generating signals indicative of the sound.

[0017] The teachings detailed herein are applicable, in at least some implementations, to any type of implantable or non-implantable stimulation and/or measurement system or device (e.g., implantable or non-implantable auditory prosthesis device or system). Implementations can include any type of medical device that can utilize the teachings detailed herein and/or variations thereof. Furthermore, while certain implementations are described herein in the context of auditory prosthesis devices, certain other implementations are compatible in the context of other types of devices or systems.

[0018] Merely for ease of description, apparatus and methods disclosed herein are primarily described with reference to an illustrative medical device, namely an implantable transducer assembly including but not limited to: electro-acoustic electrical/acoustic systems, cochlear implant devices, implantable hearing aid devices, middle ear implant devices, bone conduction devices (e.g., active bone conduction devices; passive bone conduction devices, percutaneous bone conduction devices; transcutaneous bone conduction devices), Direct Acoustic Cochlear Implant (DACI), middle ear transducer (MET), electro-acoustic implant devices, other types of auditory prosthesis devices, and/or combinations or variations thereof, or any other suitable hearing prosthesis system with or without one or more external components. Implementations can include any type of auditory prosthesis that can utilize the teachings detailed herein and/or variations thereof. Certain such implementations can be referred to as “partially implantable,” “semi-implantable,” “mostly implantable,” “fully implantable,” or “totally implantable” auditory prostheses. In some implementations, the teachings detailed herein and/or variations thereof can be utilized in other types of prostheses beyond auditory prostheses.

[0019] For example, certain other implementations are compatible in the context of other types of sensory prosthesis systems that are configured to evoke other types of neural or sensory (e.g., sight, tactile, smell, taste) percepts are compatible with certain implementations described herein, including but are not limited to: vestibular devices (e.g., vestibular implants), visual devices (e.g., bionic eyes), visual prostheses (e.g., retinal implants), somatosensory implants, and chemosensory implants. Certain other implementations are compatible with other types of medical devices that can utilize the teachings detailed herein and/or variations thereof to provide a wide range of therapeutic benefits to recipients, patients, or other users (e.g., epilepsy monitoring systems; pain control systems; bladder control systems; sleep apnea control systems; neurostimulators; pacemakers; other medical implants) or to perform monitoring or measuring functionalities (e.g., electroencephalogram monitoring of brain function; electrocardiogram monitoring of heart function).

[0020] FIG. 1A is a perspective view of an example cochlear implant auditory prosthesis 100 implanted in a recipient in accordance with certain implementations described herein. The example auditory prosthesis 100 is shown in FIG. 1A as comprising an implanted stimulator unit 120 and a microphone assembly 124 that is external to the recipient (e.g., a partially implantable cochlear implant). An example auditory prosthesis 100 (e.g., a totally implantable cochlear implant; a mostly implantable cochlear implant) in accordance with certain implementations described herein can replace the external microphone assembly 124 shown in FIG. 1 A with a subcutaneously implantable microphone assembly, as described more fully herein. In certain implementations, the example cochlear implant auditory prosthesis 100 of FIG. 1 A can be in conjunction with a reservoir of liquid medicament as described herein.

[0021] As shown in FIG. 1A, the recipient has an outer ear 101, a middle ear 105, and an inner ear 107. In a fully functional ear, the outer ear 101 comprises an auricle 110 and an ear canal 102. An acoustic pressure or sound wave 103 is collected by the auricle 110 and is channeled into and through the ear canal 102. Disposed across the distal end of the ear canal 102 is a tympanic membrane 104 which vibrates in response to the sound wave 103. This vibration is coupled to oval window or fenestra ovalis 112 through three bones of middle ear 105, collectively referred to as the ossicles 106 and comprising the malleus 108, the incus 109, and the stapes 111. The bones 108, 109, and 111 of the middle ear 105 serve to filter and amplify the sound wave 103, causing the oval window 112 to articulate, or vibrate in response to vibration of the tympanic membrane 104. This vibration sets up waves of fluid motion of the perilymph within cochlea 140. Such fluid motion, in turn, activates tiny hair cells (not shown) inside the cochlea 140. Activation of the hair cells causes appropriate nerve impulses to be generated and transferred through the spiral ganglion cells (not shown) and auditory nerve 114 to the brain (also not shown) where they are perceived as sound.

[0022] As shown in FIG. 1A, the example auditory prosthesis 100 comprises one or more components which are temporarily or permanently implanted in the recipient. The example auditory prosthesis 100 is shown in FIG. 1A with an external component 142 which is directly or indirectly attached to the recipient’s body, and an internal component 144 which is temporarily or permanently implanted in the recipient (e.g., positioned in a recess of the temporal bone adjacent auricle 110 of the recipient). The external component 142 typically comprises one or more sound input elements (e.g., an external microphone 124) for detecting sound, a sound processing unit 126 (e.g., disposed in a Behind-The-Ear unit), a power source (not shown), and an external transmitter unit 128. In the illustrative implementations of FIG. 1A, the external transmitter unit 128 comprises an external coil 130 (e.g., a wire antenna coil comprising multiple turns of electrically insulated single-strand or multi-strand platinum or gold wire) and, preferably, a magnet (not shown) secured directly or indirectly to the external coil 130. The external coil 130 of the external transmitter unit 128 is part of an inductive radio frequency (RF) communication link with the internal component 144. The sound processing unit 126 processes the output of the microphone 124 that is positioned externally to the recipient’s body, in the depicted implementation, by the recipient’s auricle 110. The sound processing unit 126 processes the output of the microphone 124 and generates encoded signals, sometimes referred to herein as encoded data signals, which are provided to the external transmitter unit 128 (e.g., via a cable). As will be appreciated, the sound processing unit 126 can utilize digital processing techniques to provide frequency shaping, amplification, compression, and other signal conditioning, including conditioning based on recipient-specific fitting parameters. [0023] The power source of the external component 142 is configured to provide power to the auditory prosthesis 100, where the auditory prosthesis 100 includes a battery (e.g., located in the internal component 144, or disposed in a separate implanted location) that is recharged by the power provided from the external component 142 (e.g., via a transcutaneous energy transfer link). The transcutaneous energy transfer link is used to transfer power and/or data to the internal component 144 of the auditory prosthesis 100. Various types of energy transfer, such as infrared (IR), electromagnetic, capacitive, and inductive transfer, may be used to transfer the power and/or data from the external component 142 to the internal component 144. During operation of the auditory prosthesis 100, the power stored by the rechargeable battery is distributed to the various other implanted components as needed.

[0024] The internal component 144 comprises an internal receiver unit 132, a stimulator unit 120, and an elongate electrode assembly 118. In some implementations, the internal receiver unit 132 and the stimulator unit 120 are hermetically sealed within a biocompatible housing. The internal receiver unit 132 comprises an internal coil 136 (e.g., a wire antenna coil comprising multiple turns of electrically insulated single-strand or multistrand platinum or gold wire), and preferably, a magnet (also not shown) fixed relative to the internal coil 136. The internal receiver unit 132 and the stimulator unit 120 are hermetically sealed within a biocompatible housing, sometimes collectively referred to as a stimulator/receiver unit. The internal coil 136 receives power and/or data signals from the external coil 130 via a transcutaneous energy transfer link (e.g., an inductive RF link). The stimulator unit 120 generates electrical stimulation signals based on the data signals, and the stimulation signals are delivered to the recipient via the elongate electrode assembly 118.

[0025] The elongate electrode assembly 118 has a proximal end connected to the stimulator unit 120, and a distal end implanted in the cochlea 140. The electrode assembly 118 extends from the stimulator unit 120 to the cochlea 140 through the mastoid bone 119. In some implementations, the electrode assembly 118 may be implanted at least in the basal region 116, and sometimes further. For example, the electrode assembly 118 may extend towards apical end of cochlea 140, referred to as cochlea apex 134. In certain circumstances, the electrode assembly 118 may be inserted into the cochlea 140 via a cochleostomy 122. In other circumstances, a cochleostomy may be formed through the round window 121, the oval window 112, the promontory 123, or through an apical turn 147 of the cochlea 140. [0026] The elongate electrode assembly 118 comprises a longitudinally aligned and distally extending array 146 of electrodes or contacts 148, sometimes referred to as electrode or contact array 146 herein, disposed along a length thereof. Although the electrode array 146 can be disposed on the electrode assembly 118, in most practical applications, the electrode array 146 is integrated into the electrode assembly 118 (e.g., the electrode array 146 is disposed in the electrode assembly 118). As noted, the stimulator unit 120 generates stimulation signals which are applied by the electrodes 148 to the cochlea 140, thereby stimulating the auditory nerve 114.

[0027] While FIG. 1 A schematically illustrates an auditory prosthesis 100 utilizing an external component 142 comprising an external microphone 124, an external sound processing unit 126, and an external power source, in certain other implementations, one or more of the microphone 124, sound processing unit 126, and power source are implantable on or within the recipient (e.g., within the internal component 144). For example, the auditory prosthesis 100 can have each of the microphone 124, sound processing unit 126, and power source implantable on or within the recipient (e.g., encapsulated within a biocompatible assembly located subcutaneously), and can be referred to as a totally implantable cochlear implant (“TICI”). For another example, the auditory prosthesis 100 can have most components of the cochlear implant (e.g., excluding the microphone, which can be an in-the-ear-canal microphone) implantable on or within the recipient, and can be referred to as a mostly implantable cochlear implant (“MICI”).

[0028] FIG. IB schematically illustrates a perspective view of an example fully implantable auditory prosthesis 200 (e.g., fully implantable middle ear implant or totally implantable acoustic system), implanted in a recipient, utilizing an acoustic actuator in accordance with certain implementations described herein. The example auditory prosthesis 200 of FIG. IB comprises a biocompatible implantable assembly 202 (e.g., comprising an implantable capsule) located subcutaneously (e.g., beneath the recipient’s skin and on a recipient's skull). While FIG. IB schematically illustrates an example implantable assembly 202 comprising a microphone, in other example auditory prostheses 200, a pendant microphone can be used (e.g., connected to the implantable assembly 202 by a cable). The implantable assembly 202 includes a signal receiver 204 (e.g., comprising a coil element) and an acoustic transducer 206 (e.g., a microphone comprising a diaphragm and an electret or piezoelectric transducer) that is positioned to receive acoustic signals through the recipient’s overlying tissue. The implantable assembly 202 may further be utilized to house a number of components of the fully implantable auditory prosthesis 200. For example, the implantable assembly 202 can include an energy storage device and a signal processor (e.g., a sound processing unit). Various additional processing logic and/or circuitry components can also be included in the implantable assembly 202 as a matter of design choice.

[0029] For the example auditory prosthesis 200 shown in FIG. IB, the signal processor of the implantable assembly 202 is in operative communication (e.g., electrically interconnected via a wire 208) with an actuator 210 (e.g., comprising a transducer configured to generate mechanical vibrations in response to electrical signals from the signal processor). In certain implementations, the example auditory prosthesis 100, 200 shown in FIGs. 1A and IB can comprise an implantable microphone assembly, such as the microphone assembly 206 shown in FIG. IB. For such an example auditory prosthesis 100, the signal processor of the implantable assembly 202 can be in operative communication (e.g., electrically interconnected via a wire) with the microphone assembly 206 and the stimulator unit of the main implantable component 120. In certain implementations, at least one of the microphone assembly 206 and the signal processor (e.g., a sound processing unit) is implanted on or within the recipient.

[0030] The actuator 210 of the example auditory prosthesis 200 shown in FIG. IB is supportably connected to a positioning system 212, which in turn, is connected to a bone anchor 214 mounted within the recipient's mastoid process (e.g., via a hole drilled through the skull). The actuator 210 includes a connection apparatus 216 for connecting the actuator 210 to the ossicles 106 of the recipient. In a connected state, the connection apparatus 216 provides a communication path for acoustic stimulation of the ossicles 106 (e.g., through transmission of vibrations from the actuator 210 to the incus 109).

[0031] During normal operation, ambient acoustic signals (e.g., ambient sound) impinge on the recipient’ s tissue and are received transcutaneously at the microphone assembly 206. Upon receipt of the transcutaneous signals, a signal processor within the implantable assembly 202 processes the signals to provide a processed audio drive signal via wire 208 to the actuator 210. As will be appreciated, the signal processor may utilize digital processing techniques to provide frequency shaping, amplification, compression, and other signal conditioning, including conditioning based on recipient-specific fitting parameters. The audio drive signal causes the actuator 210 to transmit vibrations at acoustic frequencies to the connection apparatus 216 to affect the desired sound sensation via mechanical stimulation of the incus 109 of the recipient.

[0032] The subcutaneously implantable microphone assembly 202 is configured to respond to auditory signals (e.g., sound; pressure variations in an audible frequency range) by generating output signals (e.g., electrical signals; optical signals; electromagnetic signals) indicative of the auditory signals received by the microphone assembly 202, and these output signals are used by the auditory prosthesis 100, 200 to generate stimulation signals which are provided to the recipient’s auditory system. To compensate for the decreased acoustic signal strength reaching the microphone assembly 202 by virtue of being implanted, the diaphragm of an implantable microphone assembly 202 can be configured to provide higher sensitivity than are external non-implantable microphone assemblies. For example, the diaphragm of an implantable microphone assembly 202 can be configured to be more robust and/or larger than diaphragms for external non-implantable microphone assemblies.

[0033] The example auditory prostheses 100 shown in FIG. 1 A utilizes an external microphone 124 and the auditory prosthesis 200 shown in FIG. IB utilizes an implantable microphone assembly 206 comprising a subcutaneously implantable acoustic transducer. In certain implementations described herein, the auditory prosthesis 100 utilizes one or more implanted microphone assemblies on or within the recipient. In certain implementations described herein, the auditory prosthesis 200 utilizes one or more microphone assemblies that are positioned external to the recipient and/or that are implanted on or within the recipient, and utilizes one or more acoustic transducers (e.g., actuator 210) that are implanted on or within the recipient. In certain implementations, an external microphone assembly can be used to supplement an implantable microphone assembly of the auditory prosthesis 100, 200. Thus, the teachings detailed herein and/or variations thereof can be utilized with any type of external or implantable microphone arrangement, and the acoustic transducers shown in FIGs. 1A and IB are merely illustrative.

[0034] FIG. 2A schematically illustrates a top view of an example apparatus 300 in accordance with certain implementations described herein. FIG. 2B schematically illustrates a cross-sectional view of the example apparatus 300 of FIG. 2A in accordance with certain implementations described herein and a device 400 external to the recipient’s body. FIGs. 2C- 2E schematically illustrate top views of other example apparatus 300 in accordance with certain implementations described herein.

[0035] The apparatus 300 comprises at least one housing 310 configured to be implanted beneath a skin portion 530 (e.g., skin layer) of a recipient’s body. The at least one housing 310 comprises a first housing portion 310a and a second housing portion 310b. The apparatus 300 further comprises an electrically conductive coil 320 within the first housing portion 310a and configured to transcutaneously and wirelessly receive power from an external device 400 outside (e.g., above; on) the skin portion 530. The apparatus 300 further comprises at least one sensor 330 at least partially on or within the first housing portion 310a. The at least one sensor 330 is configured to receive stimuli (e.g., sound; light that passes through the recipient’s tissue) and to generate electrical signals indicative of the stimuli. The apparatus 300 further comprises circuitry 340 within the second housing portion 310b. The circuitry 340 is configured to receive the power from the coil 320, to receive the electrical signals from the at least one sensor 330, and to generate stimulation signals indicative of the stimuli.

[0036] In certain implementations, the apparatus 300 is part of a transcutaneous system (e.g., auditory prosthesis system; vestibular prosthesis system) comprising the apparatus 300 (e.g., an implanted portion of an acoustic prosthesis system or vestibular prosthesis system) and the device 400 (e.g., an external portion of the acoustic prosthesis system or vestibular prosthesis system). For an auditory prosthesis system, the stimuli received by the at least one sensor 330 can comprise sound (e.g., from a source external to the recipient’s body) and the electrical signals generated by the at least one sensor 330 can be indicative of the sound. For a vestibular prosthesis system, the stimuli received by the at least one sensor 330 can comprise light (e.g., from a source external to the recipient’s body; ambient light) that passes through the recipient’s tissue and the electrical signals generated by the at least one sensor 330 can be indicative of the light. The apparatus 300 can be configured to be implanted on and substantially parallel to a bone surface 510 (e.g., a surface of a portion of the skull 520; a surface of the mastoid bone 119) within a recipient and the external device 400 can be configured to be worn on a portion of the recipient’s skin portion 530 over the apparatus 300. The device 400 can comprise a housing 410 (e.g., biocompatible; skin-friendly) and an electrically conductive coil 420 configured to provide power and/or data to the apparatus 300 and/or to receive data from the apparatus 300 via magnetic induction with the electrically conductive coil 320 of the apparatus 300. For example, the coil 320 can be configured to inductively receive power signals transmitted transcutaneously from the device 400, to receive transcutaneously transmitted data and/or control signals from the device 400, and/or to transcutaneously transmit data and/or control signals to the device 400.

[0037] In certain implementations, the at least one housing 310 is configured to be positioned beneath the skin portion 530 and other tissue (e.g., fat and/or muscular 408 layers) and above and on the bone surface 510 in a portion of the recipient’s body (e.g., the head). For example, the at least one housing 310 can be substantially parallel to the bone surface 510 (e.g., schematically illustrated in FIG. 2B). In certain implementations, the at least one housing 310 can be bent to be compatible with (e.g., conforms to; follows) a curvature of the bone surface 510, while in certain other implementations, the bone surface 510 can be altered (e.g., machined) to provide a portion with which the at least one housing 310 is compatible. In certain implementations, the at least one housing 310 can be configured to be affixed to the bone surface 510 using at least one biocompatible anchor, screw, or adhesive.

[0038] In certain implementations, the first housing portion 310a and the second housing portion 310b are portions of a single unitary housing 310, while in certain other implementations, the first housing portion 310a and the second housing portion 310b are separate housings that can be in contact with one another or can be spaced from one another and attached to one another (e.g., electrically connected to one another by at least one electrical conduit). As schematically illustrated in FIGs. 2A and 2B, the first housing portion 310a contains the second housing portion 310b therein.

[0039] In certain implementations, the first housing portion 310a comprises an electrically insulative and biocompatible material (e.g., silicone rubber; polymer; polyetheretherketone (PEEK); ceramic; titanium oxide; glass; glycerine). The first housing portion 310a can also be substantially transparent to the electromagnetic or magnetic fields between the coil 320 of the apparatus 300 and the coil 420 of the device 400 (e.g., such that the first housing portion 310a does not substantially interfere with power transmission from the device 400 to the apparatus 300 and/or data transmission to and/or from the apparatus 300). The first housing portion 310a of certain implementations is configured to hermetically seal the coil 320 from an environment surrounding the first housing portion 310a. [0040] In certain implementations, the second housing portion 310b comprises an electrically insulative and biocompatible material (e.g., silicone rubber; polymer; polyetheretherketone (PEEK); ceramic; titanium oxide; glass; glycerine) or an electrically conductive and biocompatible material (e.g., titanium; titanium alloy). The second housing portion 310b can shield the circuitry 340 contained therein from electromagnetic or magnetic fields that could otherwise affect operation of the circuitry 340. The second housing portion 310b of certain implementations is configured to hermetically seal the circuitry 340 from an environment surrounding the second housing portion 310b.

[0041] In certain implementations, the coil 320 is substantially planar and comprises multiple turns of electrically insulated single-strand or multi-strand wire (e.g., a planar electrically conductive wire with multiple windings having a substantially circular, rectangular, spiral, or oval shape or other shape) or metal traces on epoxy of a printed circuit board. For example, as shown in FIG. 2B, the wires of the coil 320 can extend substantially parallel to a plane 322 and can have a diameter, length, and/or width (e.g., along a lateral direction substantially parallel to the bone surface 510) less than or equal to 100 millimeters (e.g., in a range of 15 millimeters to 40 millimeters; in a range of 25 millimeters to 50 millimeters; in a range of less than 30 millimeters; in a range of 20 millimeters to 60 millimeters; in a range greater than 60 millimeters). The coil 320 can at least partially bound or surround a region 324 (e.g., the region 324 surrounded by a periphery of the coil 320). In certain implementations, the coil 320 is configured to inductively receive signals (e.g., power, data, and/or control signals) generated externally to the recipient by the device 400 and/or to inductively transmit signals (e.g., power, data, and/or control signals) to the device 400.

[0042] In certain implementations, the circuitry 340 is configured to receive electrical signals from the coil 320 and/or to transmit electrical signals to the coil 320. For example, electrical conduits 326 (e.g., comprising electrical feedthrough pins extending through the second housing portion 310b) can be connected to both the coil 320 and the circuitry 340. The circuitry 340 can comprise one or more active elements (e.g., stimulator unit 120; assembly 202; vibrating actuator) configured to deliver stimuli (e.g., stimulation signals) to a portion of the recipient’s body and/or to detect an attribute or condition of the recipient’s body. The circuitry 340 can be in electrical communication with the portion of the recipient’s body via electrical conduits 342 (e.g., electrode assembly 118; return electrode) in electrical communication with the circuitry 340 and extending from the second housing portion 310b to a region of the recipient’s body. The electrical conduits 342 can provide the stimulation signals to a portion of the recipient’s body to evoke a sensory (e.g., hearing; balance) percept by the recipient.

[0043] The circuitry 340 can comprise one or more microprocessors (e.g., application-specific integrated circuits; generalized integrated circuits programmed by software with computer executable instructions; microelectronic circuitry; microcontrollers) and at least one storage device (e.g., at least one tangible or non-transitory computer readable storage medium; read only memory; random access memory; flash memory) configured to store information (e.g., data; commands) accessed by the one or more microprocessors during operation. The at least one storage device can be encoded with software (e.g., a computer program downloaded as an application) comprising computer executable instructions for instructing the one or more microprocessors (e.g., executable data access logic, evaluation logic, and/or information outputting logic). In certain implementations, the one or more microprocessors execute the instructions of the software to provide functionality as described herein. The circuitry 340 can be configured to receive power signals, data signals, and/or control signals wirelessly communicated from the device 400 via the coil 420 and the coil 320. In certain implementations, the circuitry 340 comprises a power storage device (e.g., battery; capacitor) configured to store electrical power to be used by the apparatus 300 during operation.

[0044] In certain implementations, the apparatus 300 further comprises a magnetic element 350 (e.g., magnetic cassette) within the first housing portion 310a (e.g., the first housing portion 310a is configured to hermetically seal the magnetic element 350 from the environment surrounding the first housing portion 310a). The magnetic element 350 can be configured to generate a magnetic force with the device 400 external to the recipient’s body. In certain implementations, the magnetic element 350 comprises at least one magnetic material (e.g., ferromagnetic; ferrimagnetic; permanent magnet; diamagnetic magnet) and has a substantially planar shape (e.g., disk; plate; substantially circular, oval, or rectangular). The magnetic element 350 can be configured to interact with a portion of the device 400 (e.g., a magnetic element 450) when the device 400 is positioned on or over the skin portion 530 of the recipient above the apparatus 300. The interaction can generate a magnetic attraction force with sufficient strength to hold the device 400 onto the recipient’s skin portion 530 such that the coil 420 is in operative wireless communication with the coil 320 of the apparatus 300 to wirelessly and transcutaneously transfer energy from the device 400 to the apparatus 300 (e.g., via magnetic induction; via a radio-frequency or RF link) and/or to transmit data and/or control signals between the apparatus 300 and the device 400. In certain implementations, as shown in FIGs. 2A-2E, at least a portion of the magnetic element 350 can be positioned within the region 324 at least partially bounded or surrounded by the coil 320. For example, the magnetic element 350 and the coil 320 can both be substantially circular in the plane 322, substantially coplanar with one another, and/or substantially concentric with one another, with the coil 320 encircling the magnetic element 350.

[0045] In certain implementations, the at least one sensor 330 is located above, below, or within a periphery of the coil 320 (e.g., above, below, or within the region 324; between the magnetic element 350 and the coil 320; see, e.g., FIGs. 2C and 2E), outside a periphery of the coil 320 (between the coil 320 and the second housing portion 310b containing the circuitry 340; see, e.g., FIG. 2D), and/or between the coil 320 and the external device 400 (e.g., between the magnetic element 350 and the external device 400; see, e.g., FIGs. 2A-2B). In certain implementations in which the stimuli comprises sound, by having the at least one sensor 330 in proximity to the coil 320, which is generally positioned above the ear at a location that receives less body noise than other locations closer to the spine and/or jaw, certain implementations described herein are less affected by body noise.

[0046] While FIGs. 2A-2E schematically illustrate the sensor 330 above the coil 320 (e.g., above the plane 322; between the plane 322 and the skin portion 530), the at least one sensor 330 can comprise sensors 330 below the coil 320 (e.g., below the plane 322; between the plane and the bone surface 510). For example, the at least one housing 310 can be configured to be implanted on the bone surface 510 of the recipient’s body with the at least one sensor 330 located between the coil 320 and the bone surface 510 and/or between the magnetic element 350 and the bone surface 510.

[0047] While FIGs. 2A-2D schematically illustrate the apparatus 300 comprising a single sensor 330 at least partially on or within the first housing portion 310a, the apparatus 300 can comprise a plurality of sensors 330 on or within the first housing portion 310a and located at different positions relative to the coil 320. For example, the plurality of sensors 330 can comprise two sensors 330 (see, e.g., FIG. 2E). The circuitry 340 of certain such implementations is configured to receive the electrical signals from the plurality of sensors 330 and to process the electrical signals to enhance the detection of the stimuli. For example, in certain implementations in which the stimuli comprises sound, a first sensor 330a can be positioned above the plane 332 and sensitive to both external sound contributions and body noise contributions and a second sensor 330 can be positioned below the plane 322 and more sensitive to the body noise contribution to the sound than to the external sound contributions. The circuitry 340 can process the electrical signals to reduce (e.g., remove; cancel) the body noise contribution by subtracting a signal proportional to the electrical signals from the second sensor 330b from the electrical signals from the first sensor 330a and to generate the stimulation signals in response to the processed electrical signals. For another example, a first sensor 330a can be sensitive to both external sound contributions and external noise contributions and a second sensor 330 can be more sensitive to the external noise contribution to the sound than to the external sound contributions. The circuitry 340 can process the electrical signals to reduce (e.g., remove; cancel) the external noise contribution by subtracting a signal proportional to the electrical signals from the second sensor 330b from the electrical signals from the first sensor 330a and to generate the stimulation signals in response to the processed electrical signals. For another example, a first sensor 330a can be positioned at a first location and a second sensor 330b can be positioned at a second location different from the first location, such that a sound signal reaches the first and second sensors 330a, b at different times. The circuitry 340 can utilize the relative times of arrival of the sound signal at the first and second sensors 330a, b to process the electrical signals from both the first and second sensors 330a,b to perform beam forming to provide selectivity of sound from a particular direction and to generate the stimulation signals in response to the processed electrical signals. For another example, an external device worn behind the ear can comprise an external microphone that is more sensitive to external sound contributions and the external device can be in wireless communication (e.g., via Bluetooth) with the apparatus 300. The at least one sensor 330 can be more sensitive to body noise contributions and the circuitry 340 can process the electrical signals from the external device and from the at least one sensor 330 to reduce (e.g., remove; cancel) the body noise contributions by subtracting a signal proportional to the electrical signals from the at least one sensor 330 from the electrical signals from the external device and to generate the stimulation signals in response to the processed electrical signals.

[0048] In certain implementations, as shown in FIGs. 2A and 2C-2E, the at least one sensor 330 is in electrical communication with the circuitry 340 via at least one electrical conduit 336 (e.g., comprising at least one electrical feedthrough pin extending through the second housing portion 310b). In certain implementations, the at least one sensor 330 is hermetically sealed within the first housing portion 310a. In certain other implementations, the at least one sensor 330 is located with a non -hermetic portion of the first housing portion 310a and the at least one sensor 330 comprises a biocompatible casing. As compared to pendant-type implantable microphones, certain implementations described herein can have a smaller footprint and/or size, more simplified surgical implantation processes, and/or reduced implantation costs (e.g., without a second hermetically sealed housing; no cable).

[0049] In certain implementations, the at least one sensor 330 comprises at least one element having at least one characteristic configured to vary in response to the stimuli, the at least one characteristic selected from the group consisting of: shape; inductance; capacitance; self-resonance; resistance; voltage. For example, the at least one element can be configured to change shape in response to sound such that the sound creates a variation of the inductance, self -resonance, capacitance, or resistance of the at least one element. For another example, the at least one element can comprise a piezoelectric material configured to generate a voltage difference in response to sound (e.g., in response to mechanical distortion, bending, or stresses of the piezoelectric material from sound vibrations impinging the sensor 330). For another example, the at least one element can comprise at least two electrically conductive elements (e.g., plates; surfaces) configured to move relative to one another in response to sound such that a capacitance between the two electrically conductive elements ins indicative of the sound. The region between the two electrically conductive elements can comprise a gas or other easily compressible material. One of the at least two electrically conductive elements can comprise at least a portion of the coil 320 and/or at least a portion of the magnetic element 350. For another example, the at least one element can comprise an electrically conductive first element and a magnetic second element, the first and second elements configured to move relative to one another in response to sound such that a time-varying electric current indicative of the sound is induced within the first element by the second element. The magnetic second element can comprise at least a portion of the magnetic element 350 (e.g., configured to generate an attractive magnetic force with the external device 400 to hold the external device 400 on the skin portion 530 above the coil 320).

[0050] In certain implementations, the external device 400 blocks at least a portion of the stimuli (e.g., external sound; ambient light) from reaching the at least one sensor 330 such that the performance of the at least one sensor 330 is better when the device 400 is not worn as compared to when the device 400 is worn. For example, the at least one sensor 330 can have a first sensing capability (e.g., sensitivity) to the stimuli while the device 400 is not worn above the skin portion 530 and can have a second sensing capability to the stimuli while the device 400 is worn above the skin portion 530, the second sensing capability lower than the first sensing capability.

[0051] FIG. 3A schematically illustrates a cross-sectional view of another example apparatus 300 in accordance with certain implementations described herein. The apparatus 300 comprises a housing 310 (e.g., electrically insulative body) configured to be implanted on or within a recipient and an electrically conductive coil 320 (e.g., substantially planar antenna coil) within the housing 310. The coil 320 is configured to wirelessly receive electrical signals from a signal source (e.g., device 400) through tissue (e.g., skin portion 530) between the coil 320 and the signal source. The apparatus 300 further comprises at least one active pressure sensing assembly 600. The at least one active pressure sensing assembly 600 comprises a chamber 610 (e.g., bladder) comprising a flexible and resilient wall portion 612 and gas (e.g., air; nitrogen; inert gas) within the chamber 610 and a gas pressure sensor 620 in fluidic communication with the gas within the chamber 610. The chamber 610 is positioned between the coil 320 and the tissue, and the wall portion 612 is configured to flex in response to acoustic pressure waves propagating through the tissue and impinging the chamber 610 such that the acoustic pressure waves propagate through the gas. The gas pressure sensor 620 is configured to receive the acoustic pressure waves propagating through the gas and to generate signals (e.g., electrical signals) indicative of the acoustic pressure waves. By not having electrically conductive material between the coil 320 and the device 400, certain implementations described herein reduce (e.g., avoid) reduction of coil performance that would result from electrically conductive materials in this region. [0052] In certain implementations, the chamber 610 has a thickness in a first direction substantially perpendicular to the coil 320 (e.g., substantially perpendicular to the plane 322) and a width in a second direction substantially perpendicular to the first direction (e.g., substantially parallel to the plane 322), the width greater than the thickness. For example, the thickness can be in a range of 1 millimeter to 5 millimeters and the width can be in a range of 10 millimeters to 60 millimeters (e.g., in a range of 25 millimeters to 50 millimeters; in a range of 10 millimeters to 30 millimeters; in a range of 20 millimeters to 60 millimeters). While the cross-sectional view of FIG. 3 shows the width of the chamber 610 in a first lateral direction substantially parallel to the plane 322, the chamber 610 can have a second width in a second lateral direction substantially parallel to the plane 322 and substantially perpendicular to the first lateral direction, the second width also greater than the thickness (e.g., the second width in a range of 10 millimeters to 60 millimeters; in a range of 25 millimeters to 50 millimeters; in a range of 10 millimeters to 30 millimeters; in a range of 20 millimeters to 60 millimeters).

[0053] In certain implementations, as schematically illustrated by FIG. 3A, the wall portion 612 comprises a top wall portion of the first housing portion 310a between the coil 320 and the device 400, the top wall portion comprising an electrically insulative and biocompatible material (e.g., silicone rubber; polymer; polyether-etherketone (PEEK); ceramic; titanium oxide; glass; glycerine). The wall portion 612 can also be substantially transparent to the electromagnetic or magnetic fields between the coil 320 and the coil 420 of the device 400 (e.g., such that the wall portion 612 does not substantially interfere with power transmission from the device 400 to the apparatus 300 and/or data transmission to and/or from the apparatus 300).

[0054] In certain implementations, as schematically illustrated by FIG. 3A, the gas pressure sensor 620 is spaced from the chamber 610 and the at least one active pressure sensing assembly 600 further comprises at least one elongate gas conduit 630 (e.g., tube) configured to allow the acoustic pressure waves to propagate from the chamber 610 to the gas pressure sensor 620. In certain implementations, as schematically illustrated by FIG. 3A, the at least one active pressure sensing assembly 600 further comprises at least one orifice 640 through which the acoustic pressure waves propagate between the chamber 610 and the gas pressure sensor 620. The at least one orifice 640 can be configured to amplify the acoustic pressure waves propagating therethrough, thereby providing passive amplification of the acoustic pressure waves that can facilitate higher detection sensitivity by the gas pressure sensor 620.

[0055] FIGs. 3B and 3C schematically illustrate top views of two example apparatus 300 in accordance with certain implementations described herein. As shown in FIGs. 3 A and 3B, the gas pressure sensor 620 can be outside and spaced from the second housing portion 310b containing the circuitry 340. The gas pressure sensor 620 can be electrically coupled to the circuitry 340 by at least one electrical conduit 622 (e.g., comprising at least one electrical feedthrough pin extending through the hermetic barrier of the second housing portion 310b). In certain other implementations, as schematically illustrated by FIG. 3C, the gas conduit 630 can extend through the hermetic barrier of the second housing portion 310b and the gas pressure sensor 620 can be within the second housing portion 310b, such that the acoustic pressure waves pass through the hermetic barrier to the gas pressure sensor 620.

[0056] FIG. 4 is a flow diagram of an example method 700 in accordance with certain implementations described herein. While the method 700 is described by referring to some of the structures of the example apparatus 300 of FIGs. 2A-2E and 3, other apparatus and systems with other configurations of components can also be used to perform the method 700 in accordance with certain implementations described herein.

[0057] In an operational block 710, the method 700 comprises providing a substantially planar inductive coil 320. In an operational block 720, the method 700 further comprises providing at least one pressure sensitive sensor 330 configured to receive sound and to generate electrical signals indicative of the sound. In an operational block 730, the method 700 further comprises placing the at least one sensor 330 above, below, or adjacent to the inductive coil 320. For example, the at least one sensor 330 can be within a region 324 surrounded by a periphery of the coil 320 or the at least one sensor can be outside the region 324. In an operational block 740, the method 700 further comprises hermetically sealing at least a portion of the inductive coil 320 and the at least one sensor 330 within an electrically insulating dielectric housing 310.

[0058] Although commonly used terms are used to describe the systems and methods of certain implementations for ease of understanding, these terms are used herein to have their broadest reasonable interpretations. Although various aspects of the disclosure are described with regard to illustrative examples and implementations, the disclosed examples and implementations should not be construed as limiting. Conditional language, such as, among others, "can," "could," "might," or "may," unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain implementations include, while other implementations do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more implementations or that one or more implementations necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular implementation. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a nonexclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.

[0059] It is to be appreciated that the implementations disclosed herein are not mutually exclusive and may be combined with one another in various arrangements. In addition, although the disclosed methods and apparatuses have largely been described in the context of various devices, various implementations described herein can be incorporated in a variety of other suitable devices, methods, and contexts. More generally, as can be appreciated, certain implementations described herein can be used in a variety of implantable medical device contexts that can benefit from certain attributes described herein.

[0060] Language of degree, as used herein, such as the terms “approximately,” “about,” “generally,” and “substantially,” represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately,” “about,” “generally,” and “substantially” may refer to an amount that is within ± 10% of, within ± 5% of, within ± 2% of, within ± 1 % of, or within ± 0.1% of the stated amount. As another example, the terms “generally parallel” and “substantially parallel” refer to a value, amount, or characteristic that departs from exactly parallel by ± 10 degrees, by ± 5 degrees, by ± 2 degrees, by ± 1 degree, or by ± 0.1 degree, and the terms “generally perpendicular” and “substantially perpendicular” refer to a value, amount, or characteristic that departs from exactly perpendicular by ± 10 degrees, by ± 5 degrees, by ± 2 degrees, by ± 1 degree, or by ± 0.1 degree. The ranges disclosed herein also encompass any and all overlap, sub-ranges, and combinations thereof. Language such as “up to,” “at least,” “greater than,” less than,” “between,” and the like includes the number recited. As used herein, the meaning of “a,” “an,” and “said” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “into” and “on,” unless the context clearly dictates otherwise.

[0061] While the methods and systems are discussed herein in terms of elements labeled by ordinal adjectives (e.g., first, second, etc.), the ordinal adjective are used merely as labels to distinguish one element from another (e.g., one signal from another or one circuit from one another), and the ordinal adjective is not used to denote an order of these elements or of their use.

[0062] The invention described and claimed herein is not to be limited in scope by the specific example implementations herein disclosed, since these implementations are intended as illustrations, and not limitations, of several aspects of the invention. Any equivalent implementations are intended to be within the scope of this invention. Indeed, various modifications of the invention in form and detail, in addition to those shown and described herein, will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the claims. The breadth and scope of the invention should not be limited by any of the example implementations disclosed herein but should be defined only in accordance with the claims and their equivalents.

Claims

WHAT IS CLAIMED IS:

1. An apparatus comprising: at least one housing configured to be implanted beneath a skin of a recipient’s body, the at least one housing comprising a first housing portion and a second housing portion; an electrically conductive coil within the first housing portion and configured to transcutaneously and wirelessly receive power from an external device outside the skin; and at least one sensor at least partially on or within the first housing portion, the at least one sensor configured to receive sound and to generate electrical signals indicative of the sound; and circuitry within the second housing portion, the circuitry configured to receive the power from the coil, to receive the electrical signals from the at least one sensor, and to generate stimulation signals indicative of the sound.

2. The apparatus of claim 1, wherein the at least one sensor is located above, below, or within a periphery of the coil, outside a periphery of the coil, and/or between the coil and the external device.

3. The apparatus of claim 1 or claim 2, further comprising a magnetic element within the first housing portion, the coil surrounding the magnetic element in a plane, the magnetic element configured to generate an attractive magnetic force with the external device, the attractive magnetic force configured to hold the external device on the skin above the coil, the at least one sensor located between the magnetic element and the external device and/or between the magnetic element and the coil.

4. The apparatus of claim 3, wherein the at least one housing is configured to be implanted on a bone surface of the recipient’s body with the at least one sensor located between the coil and the bone surface and/or between the magnetic element and the bone surface.

5. The apparatus of any preceding claim, wherein the at least one sensor is located between the coil and the circuitry.

6. The apparatus of any preceding claim, wherein the first housing portion comprises a non-hermetic portion and the at least one sensor is located within the non-hermetic portion and comprises a biocompatible casing.

7. The apparatus of any preceding claim, wherein the at least one sensor comprises at least one element having at least one characteristic configured to vary in response to the sound, the at least one characteristic selected from the group consisting of: shape; inductance; capacitance; self-resonance; resistance; voltage.

8. The apparatus of claim 7, wherein the at least one element comprises at least two electrically conductive elements configured to move relative to one another in response to the sound such that a capacitance between the two electrically conductive elements is indicative of the sound.

9. The apparatus of claim 8, wherein one of the at least two electrically conductive elements comprises at least a portion of the coil.

10. The apparatus of claim 7, wherein the at least one element comprises a piezoelectric material configured to generate a voltage difference in response to the sound.

11. The apparatus of claim 7, wherein the at least one element comprises an electrically conductive first element and a magnetic second element, the first and second elements configured to move relative to one another in response to the sound such that a timevarying current indicative of the sound is induced within the first element by the second element.

12. The apparatus of claim 11, wherein the magnetic second element is configured to generate an attractive magnetic force with the external device, the attractive magnetic force configured to hold the external device on the skin above the coil.

13. The apparatus of any preceding claim, wherein the at least one sensor comprises a plurality of sensors located at different positions relative to the coil, the circuitry configured to receive the electrical signals from the plurality of sensors.

14. The apparatus of claim 13, wherein the circuitry is configured to process the electrical signals to enhance detection of the sound by at least one of: removal of a body noise contribution; removal of an external noise contribution; beam forming to provide selectivity of sound from a particular direction.

15. The apparatus of any preceding claim, wherein the circuitry comprises a stimulation assembly configured to provide the stimulation signals to a portion of the recipient’s body to evoke a hearing percept by the recipient.

16. An apparatus comprising: an electrically insulative body configured to be implanted on or within a recipient; a substantially planar antenna coil within the body, the antenna coil configured to wirelessly receive electrical signals from a signal source through tissue between the antenna coil and the signal source; and at least one active pressure sensing assembly comprising: a chamber comprising a flexible and resilient wall portion and gas within the chamber, the chamber positioned between the antenna coil and the tissue, the wall portion configured to flex in response to acoustic pressure waves propagating through the tissue and impinging the chamber such that the acoustic pressure waves propagate through the gas; and a gas pressure sensor in fluidic communication with the gas within the chamber, the gas pressure sensor configured to receive the acoustic pressure waves propagating through the gas and to generate signals indicative of the acoustic pressure waves.

17. The apparatus of claim 16, wherein the chamber has a thickness in a first direction substantially perpendicular to the antenna coil and a width in a second direction substantially perpendicular to the first direction, the width greater than the thickness.

18. The apparatus of claim 16 or claim 17, wherein the at least one active pressure sensing assembly further comprises at least one elongate gas conduit configured to allow the acoustic pressure waves to propagate from the chamber to the gas pressure sensor, the gas pressure sensor spaced from the chamber.

19. The apparatus of any of claims 16 to 18, wherein the at least one active pressure sensing assembly further comprises at least one orifice through which the acoustic pressure waves propagate between the chamber and the gas pressure sensor, the at least one orifice configured to amplify the acoustic pressure waves propagating therethrough.

20. The apparatus of any of claims 16 to 19, wherein the wall portion comprises an electrically insulative material.

21. A method comprising: providing a substantially planar inductive coil; providing at least one pressure sensitive sensor configured to receive sound and to generate electrical signals indicative of the sound; placing the at least one pressure sensitive sensor above, below, or adjacent to the inductive coil; and hermetically sealing at least a portion of the inductive coil and the at least one pressure sensitive sensor within an electrically insulating dielectric casing.

22. The method of claim 21, wherein the at least one pressure sensitive sensor is within a region substantially surrounded by a periphery of the coil.

23. The method of claim 21, wherein the at least one pressure sensitive sensor is outside a region substantially surrounded by a periphery of the coil.

24. A system comprising: at least one implantable component configured to be implanted beneath a skin layer of a recipient’s body, the at least one implantable component comprising a first housing portion and a second housing portion; at least one external component configured to be worn above the skin layer of the recipient’s body; a wireless communication component within the first housing portion and configured to communicate wirelessly with the at least one external component while the at least one external component is worn above the skin layer of the recipient’s body; a sensor component at least partially on or within the first housing portion, the sensor component having a first sensing capability to stimuli while the at least one external component is not worn above the skin layer of the recipient’s body and having a second sensing capability to the stimuli while the at least one external component is worn above the skin layer of the recipient’s body, the second sensing capability lower than the first sensing capability; and circuitry within the second housing portion, the circuitry configured to receive one or both of input from the wireless communication component and signals from the sensor component.

25. The system of claim 24, wherein the wireless communication component comprises an electrically conductive coil.

26. The system of claim 25, wherein the electrically conductive coil is configured to transcutaneously and wirelessly receive power from the at least one external component.

27. The system of any of claims 24 to 26, wherein the stimuli comprises sound from a source external to the recipient’s body.

28. The system of claim 27, wherein the sensor component is configured to generate electrical signals indicative of the sound.

29. The system of claim 24, wherein the input from the wireless communication component comprises power, the signals are indicative of sound sensed by the sensor component, and the circuitry is configured to use the power and to provide stimulation signals to the recipient, the stimulation signals indicative of the sound.

30. The system of claim 24, wherein the at least one implantable component is configured to transcutaneously and wirelessly receive signals indicative of sound from the at least one external component.

31. The system of claim 30, wherein the circuitry is configured to provide stimulation signals to the recipient, the stimulation signals indicative of the sound.