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WO2025160472A1 - Procédés et appareils de détection électrique de caillot sanguin - Google Patents

Procédés et appareils de détection électrique de caillot sanguin

Info

Publication number
WO2025160472A1
WO2025160472A1 PCT/US2025/013045 US2025013045W WO2025160472A1 WO 2025160472 A1 WO2025160472 A1 WO 2025160472A1 US 2025013045 W US2025013045 W US 2025013045W WO 2025160472 A1 WO2025160472 A1 WO 2025160472A1
Authority
WO
WIPO (PCT)
Prior art keywords
impedance
indicator
data stream
catheter
blood
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/US2025/013045
Other languages
English (en)
Inventor
Michael Pare
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.)
Inquis Medical Inc
Roseman Jared
Original Assignee
Inquis Medical Inc
Roseman Jared
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 Inquis Medical Inc, Roseman Jared filed Critical Inquis Medical Inc
Publication of WO2025160472A1 publication Critical patent/WO2025160472A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods
    • A61B17/22—Implements for squeezing-off ulcers or the like on inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; for invasive removal or destruction of calculus using mechanical vibrations; for removing obstructions in blood vessels, not otherwise provided for
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
    • A61B5/053—Measuring electrical impedance or conductance of a portion of the body
    • A61B5/0538—Measuring electrical impedance or conductance of a portion of the body invasively, e.g. using a catheter
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods
    • A61B17/32—Surgical cutting instruments
    • A61B17/3205—Excision instruments
    • A61B17/3207—Atherectomy devices working by cutting or abrading; Similar devices specially adapted for non-vascular obstructions
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods
    • A61B2017/00017—Electrical control of surgical instruments
    • A61B2017/00022—Sensing or detecting at the treatment site
    • A61B2017/00026—Conductivity or impedance, e.g. of tissue
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
    • A61B2018/00636—Sensing and controlling the application of energy
    • A61B2018/00904—Automatic detection of target tissue
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B2217/00—General characteristics of surgical instruments
    • A61B2217/002—Auxiliary appliance
    • A61B2217/005—Auxiliary appliance with suction drainage system
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow
    • A61B5/02007—Evaluating blood vessel condition, e.g. elasticity, compliance

Definitions

  • thromboembolism is characteristic of numerous common, life-threatening conditions.
  • examples of potentially fatal diseases resulting from thrombotic occlusion include pulmonary embolism, deep vein thrombosis, and acute limb ischemia.
  • Acute pulmonary embolism is a significant cause of death in the United States.
  • Pulmonary embolism can be a complication from deep vein thrombosis, which has an annual incidence of 1% in patients 60 years and older. All of the aforementioned diseases are examples of conditions in which treatment may include aspiration or evacuation of clot using a vacuum- assisted thrombectomy procedure.
  • Described herein are methods and apparatuses for identifying that a material is at or near the distal end of a catheter and/or identifying one or more characteristics of a material at or near the distal end of the catheter.
  • the catheter may be an aspiration catheter.
  • the methods and apparatuses may be configured to monitor one or more electrical property, such as impedance.
  • these methods and apparatuses may monitor, in an ongoing manner, impedance at a distal end region (e.g., at, on, or in an aspiration orifice) and may determine one or more indicators from the impedance data stream to uniquely identify that the distal end region is contacting or adjacent to (e.g., within about 1 cm, 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, etc.) the electrode(s) used to sense the impedance.
  • any of these methods and apparatuses may use a first indicator from the impedance data stream and a second indicator (which may be selected in order to disambiguate the first indicator) from the impedance data stream to determine if the distal end region is in contract with (and/or adjacent to) clot material (“clot”), vessel wall, blood, air, saline, etc.
  • these methods and apparatuses may identify the type of clot material (e.g., stiffness/viscoelasticity of the clot material, age of the clot material, fibrin content of clot material, etc.).
  • one or more additional sensing modalities in addition to electrical (e.g., impedance) sensing, may be used, such as but not limited to optical information (e.g., reflectance), and/or ultrasound.
  • the methods and/or apparatuses may use a data stream or electrical properties (e.g., an impedance data stream) from one or more electrodes to identify clot material, and/or and to distinguish clot material from blood and/or wall, by analyzing and classifying tip conditions experienced during clinical use.
  • Also described herein are methods of electrically and/or mechanically probing the local area around the catheter (e.g., the tip of an aspiration catheter) to help characterize the conditions and surrounding materials.
  • a method comprising: receiving an impedance data stream from one or more electrodes on a distal end region of a catheter; determining, in an ongoing basis based on the impedance data stream, if the one or more electrodes is in contact with air, saline, blood, non-blood tissue or clot, based on one or more of: a filtered impedance magnitude from the impedance data stream, a rise time of the impedance waveform, a slope (e.g., rate of change) of the impedance magnitude, a maximum impedance magnitude within a window of time, a minimum impedance magnitude within the window of time, a variability of the impedance magnitude within the window of time, a closeness of impedance magnitude waveform shape from the impedance data stream to a known template, and/or a blood impedance baseline level based on the impedance data stream; and outputting a state classification indicator indicating if the distal end region of the catheter is in contact with
  • a method may include: receiving an impedance data stream from one or more electrodes on a distal end region of a catheter; determining, in an ongoing basis based on the impedance data stream, if the one or more electrodes is in contact with air, saline, blood, non-blood tissue or clot, based on one or more of a filtered impedance magnitude from the impedance data stream within a window of time from the impedance data stream, a 10%-90% rise time of the impedance waveform within the window of time, a slope (e.g., rate of change) of the impedance magnitude of the impedance data stream, a maximum impedance magnitude within the window of time, a minimum impedance magnitude within the window of time, a variability of the impedance magnitude within the window of time, a closeness of impedance magnitude waveform shape from the impedance data stream to a known template, and/or a blood impedance baseline level based on the impedance data stream;
  • a slope
  • a method may include: receiving an impedance data stream from one or more electrodes on a distal end region of a catheter; determining from the impedance data stream if the one or more electrodes is in contact with one or more of: air, saline, blood, non-blood tissue or clot based on a filtered impedance magnitude from the impedance data stream within a window of time from the impedance data stream and one or more of: a rise time of the impedance within the window of time, a slope (e.g., rate of change) of the impedance magnitude from the impedance data stream, a maximum impedance magnitude within the window of time, a minimum impedance magnitude within the window of time, a variability of the impedance magnitude within the window of time, a closeness of impedance magnitude waveform shape from the impedance data stream to a known template, and/or a blood impedance baseline level based on the impedance data stream; and outputting a state classification indicator indicating if
  • any of these methods may include adjusting the size of the window of time (e.g., between 0.01 second and 100 seconds, between 0.01 second and 60 seconds, between 0.01 second and 10 seconds, between 0.01 seconds and 1 second, etc.). Any of these methods may include dynamically adjusting the size of the window of time, based on one or more of: the application of aspiration through the catheter, and/or the impedance data stream.
  • the method may include adjusting suction through a lumen of the catheter based on the state classification indicator output.
  • the state classification may include indicating if the distal end region of the catheter is in contact with a vessel wall tissue.
  • the state classification includes indicating if the distal end region of the catheter is in contact with a fluoroscopy contrast injection.
  • the state classification may include indicating if the one or more electrodes is latching onto a vessel wall.
  • the state classification may include indicating a system error.
  • determining may include determining from the impedance data stream if the one or more electrodes is in contact with one or more of: air, saline, blood, non-blood tissue or clot comprises using a trained machine learning agent.
  • determining when the one or more electrodes is in contact with clot may include determining a type of clot in contact with the one or more electrodes.
  • Any of these methods may include filtering the impedance data stream using the window of time to generate the filtered impedance magnitude.
  • any of these systems may include: an elongate flexible catheter comprising one or more electrodes; one or more processors; and a memory storing computerprogram instructions, that, when executed by the one or more processors, perform a computer-implemented method comprising any of the methods described herein.
  • a system may include: an elongate flexible catheter comprising one or more electrodes; one or more processors; and a memory storing computer-program instructions, that, when executed by the one or more processors, perform a computer- implemented method comprising receiving an impedance data stream from one or more electrodes on a distal end region of a catheter; determining, in an ongoing basis based on the impedance data stream, if the one or more electrodes is in contact with air, saline, blood, non- blood tissue or clot, based on one or more of: a filtered impedance magnitude from the impedance data stream, a rise time of the impedance waveform, a slope of the impedance magnitude, a maximum impedance magnitude within a window of time, a minimum impedance magnitude within the window of time, a variability of the impedance magnitude within the window of time, a closeness of impedance magnitude waveform shape from the impedance data stream to a known template, and/or
  • Any of these systems may be configured to adjust suction through a lumen of the catheter based on the state classification indicator output.
  • these methods may include: moving a catheter within a vessel so that one or more sensors, comprising one or more electrodes, are moved along a wall of the vessel; sensing electrical properties from the one or more sensors; determining the type of tissue from the sensed electrical properties; and identifying a side branch in the wall of the vessel based on the type of tissue identified.
  • the method may include configuring the catheter so that the one or more sensors is adjacent to the wall of the vessel.
  • Configuring the catheter may comprise bending a bend region of the catheter.
  • configuring the catheter comprises radially expanding a support holding the one or more sensors.
  • sensing electrical properties may comprise sensing impedance.
  • sensing electrical properties may comprise sensing an impedance data stream.
  • Any of these methods may include determining the type of tissue, wherein determining the type of tissue comprises using an impedance data stream to determine one or more of impedance magnitude, rise time waveform, slope (e.g., rate of change) of the magnitude over time, maximum impedance value within a window of time, variability of the impedance magnitude within a window of time, and/or comparing the magnitude waveform of the impedance to a library of known waveforms.
  • determining the type of tissue comprises using an impedance data stream to determine one or more of impedance magnitude, rise time waveform, slope (e.g., rate of change) of the magnitude over time, maximum impedance value within a window of time, variability of the impedance magnitude within a window of time, and/or comparing the magnitude waveform of the impedance to a library of known waveforms.
  • the methods of determining (or identifying) side branch may include identifying side branches that are occluded (e.g., by clot material).
  • any of the methods described herein may include removing clot material from the side branch.
  • the method may include positioning an aspiration opening on the catheter adjacent to the side branch and applying aspiration from the aspiration opening.
  • a may include: an elongate flexible catheter comprising one or more sensors, comprising one or more electrodes; one or more processors; and a memory storing computer-program instructions, that, when executed by the one or more processors, perform a computer- implemented method comprising: moving a catheter within a vessel so that the one or more sensors are moved along a wall of the vessel; sensing electrical properties from the one or more sensors; determining the type of tissue from the sensed electrical properties; and identifying a side branch in the wall of the vessel based on the type of tissue identified.
  • systems comprising: an elongate flexible catheter comprising one or more electrodes; one or more processors; and a memory storing computer-program instructions, that, when executed by the one or more processors, perform a computer-implemented method comprising: receiving an impedance data stream from one or more electrodes on a distal end region of a catheter; estimating a first indicator derived from the impedance data stream; comparing the first indicator to a first plurality of ranges to determine if the first indicator is consistent with contact with one or more of: air, clot, vessel wall, blood and/or saline; estimating a second indicator derived from the impedance data stream, wherein the second indicator is a different indicator type than the first indicator; comparing the second indicator to a second range of values to confirm that the distal end region of the catheter is in contact with one of: air, clot, vessel wall, blood and saline; and outputting a state classification indicator that the distal end region of
  • the computer-implemented instructions may be stored on the memory as software or firmware, and/or may be partially encoded by hardware or firmware.
  • the one or more processors executing the computer-program instructions may be configured to estimate in an ongoing basis, including continuously or at repeating intervals (e.g., with a frequency of about 1 kHz, 900 Hz, 800 Hz, 700 Hz, 600 Hz, 500 Hz, 400 Hz, 300 Hz, 200 Hz, 150 Hz, 100Hz, 60 Hz, 30 Hz, 20 Hz, 10 Hz, 5 Hz, 1 Hz, between about 1 Hz and 600 Hz, between about 5 Hz and 200 Hz, etc.).
  • the impedance data stream may be continuously monitored; in some examples the impedance data stream may be sampled (e.g., using an analog to digital converter) at a sampling frequency.
  • the first and/or second indicator may comprise an indicator type including one or more of: an impedance magnitude, an impedance phase, a rate of change of the impedance, a variability of the impedance, a rise time of the impedance, a maximum impedance magnitude within a window of time, a minimum impedance magnitude within the window of time, and/or a shape of impedance data stream over time.
  • the first indicator is generally derived from the impedance data stream. In some cases, the first indicator is a filtered impedance magnitude.
  • Determining the first indicator may include processing the impedance data stream by sampling it at the sampling frequency (e.g., about 1 kHz, 900 Hz, 800 Hz, 700 Hz, 600 Hz, 500 Hz, 400 Hz, 300 Hz, 200 Hz, 150 Hz, 100Hz, 60 Hz, 30 Hz, 20 Hz, 10 Hz, 5 Hz, 1 Hz, between about 1 Hz and 600 Hz, between about 5 Hz and 200 Hz, etc.), estimating the first indicator may include processing data from the impedance data stream, such as averaging, sampling, smoothing, etc.
  • the one or more processors executing the computer-program instructions may be configured to normalize the first indicator when estimating the first indicator.
  • the first indicator may be normalized to fit a predetermined range, and/or to remove outliers.
  • the impedance data stream may be normalized using a second impedance measure (or second impedance data stream, such as impedance data from a second electrode or pair of electrodes (e.g., proximally located, and/or located within a region of the catheter that is near the sensing electrodes providing the primary impedance data stream, but protected from contact with non-blood material, such as within the lumen of the aspiration orifice, etc.).
  • the impedance data stream and/or the indicator may be normalized using a prior measurement, e.g., a prior measurement taken with the same electrode(s) used to generate the impedance data stream being normalized.
  • any of the methods and apparatuses described herein may be configured to use a processed impedance data stream and/or processed one or more indicators derived from the impedance data stream, but may also transmit and refer to the raw, unprocessed impedance data stream.
  • the first indicator is based on a processed impedance data stream and/or is itself processed, while the second indicator is based on the un-processed (e.g., ‘raw’) impedance data stream.
  • the second indicator is based on a processed impedance data stream and/or is itself processed, while the first indicator is based on the unprocessed (e.g., ‘raw’) impedance data stream.
  • the unprocessed impedance data stream may be transmitted and/or stored with the processed impedance data stream and/or the first and second indicator.
  • the second indicator may be selected based on the value(s) of the first indicator.
  • the indicator type of the second indicator may be based on the comparison of the first indicator to the first plurality of ranges.
  • the value and/or type of the first indicator may determine which type of second indicator the system uses.
  • the first indicator may be a magnitude of the impedance (of an average and/or peak magnitude over a window of time) from the impedance data stream; if the value of the first indicator is greater than a first predetermined range (indicating that the material in contact with the electrode(s) is likely to be clot material or air) a second indicator that may more readily distinguish between clot material and air may be used, such as phase of the impedance data stream, pressure within the lumen of the catheter, etc.
  • a second indicator may be chosen to distinguish between blood and saline and/or blood and vessel wall, such as matching the time-varying pattern of the impedance data stream, the rate of change of the impedance data stream, the variability of the impedance data stream, etc.
  • the indicator type of the second indicator is one of: impedance magnitude, impedance phase, rate of change of the impedance, variability of the impedance, rise time of the impedance, maximum impedance magnitude within a window of time, minimum impedance magnitude within the window of time, and/or shape of impedance data stream over time.
  • the second indicator may be different from the first indicator.
  • the state classification indicator output may include triggering an operational parameter of an aspiration system including the catheter. Outputting the state classification indicator may comprise triggering a visual and/or audible output indicating that the catheter is in contact with one of: air, clot, vessel wall, blood and saline.
  • the state classification indicator may include an LED illumination of color corresponding to the state (e.g., air, blood, saline, clot, clot wall, etc.) determined for contact at the end region (e.g., aspiration orifice) of the catheter.
  • triggering an operational parameter of an aspiration system may include adjusting suction through a lumen of the catheter (starting, stopping, increasing, decreasing, etc.) based on the state determined.
  • the state classification indicator may indicate if the device (including the one or more electrodes) is latching onto a vessel wall.
  • the state classification indicator may indicate that the distal end region of the device is in air.
  • the state classification indicator may indicate that the distal end region of the device is in clot.
  • the one or more processors may be located remotely from the catheter, including but not limited to a remote server.
  • the one or more processors may be part of a cloud-based system.
  • the apparatus may transmit (via a wired or preferably a wireless connection) either or both the indicators (e.g., first and/or second) and/or the impedance data stream to a remote processor (e.g., remote server) for processing, including determining the state classification indicator.
  • a remote processor e.g., remote server
  • the apparatus may determine the indicators (first and/or second)) and/or the state classification indicator locally, including in a controller coupled to the catheter.
  • any of these apparatuses and methods may use a machine learning agent (e.g., a trained neural network, etc.) to estimate the first and/or second indicator and/or to determine the state classification indicator.
  • a machine learning agent e.g., a trained neural network, etc.
  • the apparatus may be configured to use a trained machine learning agent to estimate the first (and/or second) indicator.
  • any of these methods and apparatuses may be configured to estimate the first indicator from the impedance data stream by continuously monitoring the impedance data stream over a moving window of time.
  • the window may be of a fixed duration or a variable duration.
  • a system such as a system for determining a state classification indicator indicating if the distal end of a catheter is in contact (or adjacent to) blood, air, vessel wall, clot, etc.
  • a system may include: an elongate flexible catheter comprising one or more electrodes; one or more processors; and a memory storing computer-program instructions, that, when executed by the one or more processors, perform a computer-implemented method comprising: receiving an impedance data stream from one or more electrodes on a distal end region of a catheter; estimating, in an ongoing basis, a first indicator from the impedance data stream comprising: a magnitude, a phase, or a rate of change; estimate a second indicator from the impedance data stream, wherein the second indicator is a different indicator type than the first indicator and wherein the second indicator comprises: the magnitude, the phase, the rate of change, a variability of the impedance, a rise time of the impedance, a maximum impedance magnitude within
  • a method may include: receiving an impedance data stream from one or more electrodes on a distal end region of a catheter; estimating a first indicator derived from the impedance data stream; comparing the first indicator to a first plurality of ranges to determine if the first indicator is consistent with contact with one or more of: air, clot, vessel wall, blood and/or saline; estimating a second indicator derived from the impedance data stream, wherein the second indicator is a different indicator type than the first indicator; comparing the second indicator to a second range of values to confirm that the distal end region of the catheter is in contact with one of: air, clot, vessel wall, blood and saline; and outputting an indicator that the distal end region of the catheter
  • Estimating the first indicator may comprise estimating in an ongoing basis (e.g., continuously or periodically).
  • the first indicator may comprise one or more of: an impedance magnitude, an impedance phase, a rate of change of the impedance, a variability of the impedance, a rise time of the impedance, a maximum impedance magnitude within a window of time, a minimum impedance magnitude within the window of time, and/or a shape of impedance data stream over time.
  • the first indicator derived from the impedance data stream may comprise a filtered impedance magnitude.
  • the first indicator may be normalized when estimating from the first indicator.
  • the indicator type of the second indicator may be based on the comparison of the first indicator to the first plurality of ranges.
  • the indicator type of the second indicator may be one of: impedance magnitude, impedance phase, rate of change of the impedance, variability of the impedance, rise time of the impedance, maximum impedance magnitude within a window of time, minimum impedance magnitude within the window of time, and/or shape of impedance data stream over time.
  • the state classification indicator may trigger an operational parameter of an aspiration system including the catheter. Outputting the state classification indicator may comprise triggering a visual output indicating that the catheter is in contact with one of: air, clot, vessel wall, blood and saline.
  • a method may include: receiving an impedance data stream from one or more electrodes on a distal end region of a catheter; estimating, in an ongoing basis, a first indicator from the impedance data stream comprising: a magnitude, a phase, or a rate of change; estimate a second indicator from the impedance data stream, wherein the second indicator is a different indicator type than the first indicator and wherein the second indicator comprises: the magnitude, the phase, the rate of change, a variability of the impedance, a rise time of the impedance, a maximum impedance magnitude within a window of time, a minimum impedance magnitude within the window of time, and/or a shape of impedance data stream over time; and outputting a state indicator that indicates that the distal end region of the catheter is in contact a material consisting of one of: air, clot, vessel wall, blood and saline based on the second indicator and/or the first indicator.
  • This patent application may be related to, may improve on, and/or incorporate, one or more of features or elements of international application no. PCTUS2022035392, filed June 28, 2022, U.S. Patent Application No. 17/866,462 (filed on July 15, 2022), which issued as U.S. Patent No. 11,730,925, and U.S. Patent Application No. 18/329,532, filed on June 5, 2023, each of which is herein incorporated by reference in its entirety.
  • FIG. 1 schematically illustrates one example of an apparatus for sensing clot material.
  • FIG. 2 shows an example of a schematic for determination of tissue type/fluid type identifier.
  • FIG. 3 shows an example of a schematic for a clot detection flow chart.
  • FIG. 4 is an example of impedance magnitude ranges for various tip conditions as described herein.
  • FIG. 5 shows an example of a schematic for determination of wall latch initiation.
  • FIG. 6 is an example of a wall latch template having a wall latch signature.
  • FIGS. 7A-7C illustrate a matched filter detection of the wall latch signature.
  • FIG. 7A Impedance waveform.
  • FIG. 7B Wall latch template with wall latch signature.
  • FIG. 7C Dot product of impedance magnitude waveform with template sweeping from left to right.
  • FIGS. 7D-7G illustrate another example of a matched filter detection of the wall latch signature.
  • FIG. 7D illustrates an example of an impedance magnitude waveform
  • FIG. 7E level-shifted impedance magnitude waveform
  • FIG. 7F latch template
  • FIG. 7G dot product.
  • FIG. 8A shows an example of impedance magnitude and setting a blood impedance baseline.
  • FIG. 8B shows an example of impedance magnitude and the local or current blood impedance value.
  • FIG. 8C shows an example of impedance magnitude and setting a blood impedance baseline.
  • FIG. 9 is an example of an equivalent circuit model for tissue.
  • FIG. 11 schematically illustrates a distal end region of a catheter including electrodes for sensing impedance.
  • FIGS. 12A-12C schematically illustrates identifying the "air seen” condition.
  • FIG. 12A Unfiltered Magnitude.
  • FIG. 12B Mean filtered impedance magnitude.
  • FIG. 12C Zoomed in filtered impedance magnitude showing "Air Seen” 100 ms after remaining in the "air seen” threshold limits for 100 ms.
  • FIG. 13 shows an example of identifying the “blood seen” condition, in which impedance is between 100 Q and 1300 Q and has low variability (maximum impedance - minimum impedance ⁇ 100 Q) for 1000 ms.
  • FIG. 14 shows an example of identifying the “High-Z” condition. Impedance exceeds 80 kQ and stays in Hi-Z range (> 80 kQ) for more > 100 ms.
  • FIG. 15 shows an example of identifying the “low-Z” condition. Impedance falls below 100 Q and stays in Low-Z range ( ⁇ 100 Q) for more > 100 ms.
  • FIG. 16 shows an example of identifying the “baseline detected” condition. Impedance falls below 1300 Q for one sample.
  • FIG. 17 shows an example of identifying the “change-mind” condition. Impedance rises above 2750 Q for one sample.
  • FIG. 18 shows an example of identifying the “clot” condition. Impedance rises above “Clot Detected” threshold 37 samples ago. Delay is to give the “Latch Detected” condition a chance to be seen.
  • FIGS. 19A-19E illustrate an example of identifying the “latch detected” condition.
  • FIG. 19A Unfiltered impedance magnitude waveform.
  • FIG. 19B Mean filtered impedance waveform.
  • FIG. 19C Dot product of unfiltered impedance magnitude with template.
  • FIG 19D Maximum sample in the last 75 samples.
  • FIG. 19E Maximum single point jump in the last 75 samples.
  • FIG. 20 schematically illustrates a method as described herein for detecting one or more side branches in a vessel.
  • FIG. 21 schematically illustrates an example of a method of determining the state (e.g., the state classification indicator) indicating contact of the distal end region of a catheter with one of: blood, clot, vessel wall, air, saline, etc.
  • FIG. 22 schematically illustrates an example of a method of determining the state (e.g., the state classification indicator) indicating contact of the distal end region of a catheter with one of: blood, clot, vessel wall, air, saline, etc.
  • Described herein are methods and apparatuses for identifying that a material (e.g., clot material, blood, non-blood tissue, such as but not limited to vessel wall, etc.) at or near the distal end region of a catheter, and/or identifying the type of material at or near the catheter tip.
  • a material e.g., clot material, blood, non-blood tissue, such as but not limited to vessel wall, etc.
  • electrical monitoring such as (but not limited to) impedance monitoring, which may use electrodes positioned on a catheter, including positioned on the rim of an aspiration orifice of a catheter.
  • described herein are methods and apparatuses for using impedance data streams to identify clot material, and to distinguish clot material from blood and/or wall, by analyzing and classifying tip conditions (e.g., electrical tip conditions) experienced during clinical use. Also described herein are methods of electrically and/or mechanically probing the local area around the catheter (e.g., the tip of an aspiration catheter) to help characterize the conditions and surrounding materials.
  • tip conditions e.g., electrical tip conditions
  • methods of electrically and/or mechanically probing the local area around the catheter e.g., the tip of an aspiration catheter
  • Any of these methods may include determining a first indicator from the impedance data stream, and using a second indicator from the impedance data stream (and/or one or more other sensing modalities) to confirm the material that the distal tip region (such as the region near or at the aspiration orifice) is contacting, such as blood, saline, clot (and in some cases the type of clot and/or a mechanical or compositional characteristic of the clot material), vessel wall, and/or air.
  • An indicator may be a property or characteristic of the impedance data stream, such as but not limited to the impedance magnitude, impedance phase, rate of change of the impedance, variability of the impedance, rise time of the impedance, maximum impedance magnitude within a window of time, minimum impedance magnitude within the window of time, and/or shape of impedance data stream over time.
  • These indicators may be referred to as state indicators or state properties from the impedance data stream. In general, the indicators may be measured and/or estimate over a fixed or adjustable window of time or number of samples from the impedance data stream.
  • the methods and apparatuses described herein may use one or more than one indicator to determine the state of the material that the distal end region of the catheter (where the one or more electrodes sensing the impedance data stream are located) is contacting and/or adjacent to (e.g., within about 1 cm or less, about 9 mm or less, about 8 mm or less, about 7 mm or less, about 6 mm or less, about 5 mm or less, about 4 mm or less, about 3 mm or less, about 2 mm or less, about 1 mm or less, about 0.9 mm or less, about 0.8 mm or less, about 0.7 mm or less, about 0.5 mm or less, etc.).
  • This may be output by any of these methods and apparatuses as a state classification indicator and may be continuously output/updated during operation of the apparatus.
  • the methods and apparatuses described herein may use two or more indicators, such as a first indicator and a second indicator to quickly and reliably determine the state classification indicator.
  • a second indicator that is different from the first indicator, may disambiguate the first indicator and accurately identify the state (e.g., the material at the end of the catheter.
  • the categories of the state classification indicator may include blood, clot and vessel wall.
  • the state classification indicator may include blood, clot, vessel wall, and air (e.g., when the catheter is outside of the patient).
  • the state classification indicator may include blood, clot, vessel wall, air and saline.
  • Other states including different types of clot and/or wall) may be included as state classification indicator outcomes.
  • methods and apparatuses for interpreting and analyzing electrical monitoring data, and in particular impedance electrical data collected by electrodes placed on or near the aspiration orifice.
  • the electrical data may be collected from electrodes placed on or near the rim of an aspiration orifice of a thrombectomy catheter.
  • These methods and apparatuses may process the electrical (e.g., impedance) data to identify and classify the conditions external to and internal to a catheter during a thrombectomy procedure.
  • the methods and apparatuses for analyzing the data streams described herein may identify/classify the catheter tip condition into one of the following conditions likely to be encountered during a thrombectomy procedure (e.g., catheter tip condition classifications/identifications): one or more electrodes in contact with air, one or more electrodes in contact with saline, one or more electrodes in contact with blood, one of more electrodes in contact with non-blood tissue (e.g., catheter tip condition classifications/identifications): one or more electrodes in contact with air, one or more electrodes in contact with saline, one or more electrodes in contact with blood, one of more electrodes in contact with non-blood tissue (e.g.
  • one or more electrodes in contact with or near blood clot one or more electrodes embedded in blood clot, and/or one or more electrodes in contact with or near vessel wall (e.g., tissue, including but not limited to common tissues including inferior vena cava (IVC), main pulmonary artery (MPA), right pulmonary artery (RPA), and left pulmonary artery (LPA), etc.), the aspiration of clot passing by (touching or near) one or more electrodes, one or more electrodes latching onto vessel wall (vacuum suction of the aspiration orifice on the wall), one or more electrodes in contact with fluoroscopy contrast injection, estimation of the diameter of a vessel in which the electrodes are located, and/or identification of System/Sensing error.
  • vessel wall e.g., tissue, including but not limited to common tissues including inferior vena cava (IVC), main pulmonary artery (MPA), right pulmonary artery (RPA), and left pulmonary artery (LPA), etc.
  • FIG. 1 illustrates one example of an apparatus as described herein, which may be configured for receiving electrical signals from electrodes positioned on or near the rim of an opening (e.g., aspiration opening).
  • the apparatuses and methods described herein may be used on a device (including, but not limited to, a catheter) that generally includes one or more electrodes for applying electrical energy and detecting an impedance measurement.
  • the device may be insertable or implantable into the body. Properties of the clot material may be determined and output to a user, stored, transmitted and/or further processed.
  • the apparatus includes a flexible catheter having an elongate catheter body, a proximal end region and a distal end region.
  • the distal end region 177 is configured to be inserted into the body, including over a guidewire and/or guide catheter 137.
  • FIG. 1 includes a flexible elongate body 113 (shown in two parts in FIG. 1) that includes a distal end region 177 with a guide channel 131 for a guide or diagnostic catheter 137 (and/or guidewire) extending from a distal end opening through the length of the elongate body.
  • the distal end region may include an extraction chamber region having an aspiration opening 121 into a suction lumen that extends along the length of the flexible elongate body.
  • the aspiration opening 121 at the distal end region of the flexible elongate body in this example is sidefacing (e.g., on a tapered distal end region).
  • the distal end region may also include one or more openings into the suction lumen on a side of the distal end region that is opposite from the aspiration opening (not visible in FIG. 1).
  • the distal end region of the apparatus also includes an aspiration opening sensor comprising two electrodes 158, 158’ positioned at a rim of the aspiration opening.
  • the electrodes are positioned at the 2 o’clock and 10 o’clock position, generally towards the proximal end of the aspiration opening.
  • the electrodes may be positioned anywhere on the rim, including at the distal-most (6 o’clock) and proximal-most (12 o’clock) position, at the 3 o’clock, and the 9 o’clock position, etc.
  • the electrodes may be any appropriate size, such as between about 0.1 and 3 cm (e.g., between about 0.5 and 2 cm, etc.) long (around the perimeter of the aspiration opening).
  • the electrodes may be configured to operate as a pair (e.g., in a bipolar configuration). In some cases, the electrodes may be configured to operate as monopolar electrodes. In some examples the electrodes may be multiplexed together. It may be helpful to sense material in contact with the aspiration opening.
  • the electrode(s) may be positioned in the proximal half (e.g., the proximal 40%, proximal 35%, proximal 30%, etc., such as between the 9 o’clock and 3 o’clock, or more preferably between 10 o’clock and 2 o’clock, or between 11 o’clock and 1 o’clock positions). Additional electrodes may be positioned on the distal end region, and/or on the guidewire/guide catheter 137; in some examples, electrodes may be positioned proximal to the aspiration opening 121, on the outside and/or the inside of the catheter.
  • the proximal half e.g., the proximal 40%, proximal 35%, proximal 30%, etc., such as between the 9 o’clock and 3 o’clock, or more preferably between 10 o’clock and 2 o’clock, or between 11 o’clock and 1 o’clock positions.
  • Additional electrodes may be positioned on the distal end
  • one or more internal electrodes may be positioned just proximally to the aspiration opening and the aspiration opening electrodes 158, 158’.
  • the internal impedance sensing electrodes may be configured to detect material (e.g., clot material) within the suction lumen and may be used in conjunction (or coordinated) with the aspiration opening sensor electrodes to confirm that the aspiration opening is in contact with clot material, or to distinguish from vessel wall when force (e.g., suction) is applied to drive the distal end region, including the aspiration opening, into a material.
  • the internal impedance sensing electrodes may be spaced from the aspiration opening (proximal end) by between about 0.1 and 30 mm (e.g., between about 1 and 20 mm, between about 1 and 10 mm, etc.).
  • the internal impedance sensing electrodes in this example includes two annular electrodes, extending partially around the wall of the suction lumen, but any shape electrode may be used.
  • the internal impedance sensing electrodes may be separated from each other by any appropriate distance, e.g., between about 0.1 and 10 mm (e.g., between about 0.5 and 5 mm, 0.5 and 3 mm, etc.).
  • the electrodes may be referred to as sensing electrodes and/or impedance sensing electrodes and may each be electrically coupled to an electrical line, wire, trace, etc., extending proximally down the length of the flexible elongate body and into the proximal handle 109.
  • the suction lumen may extend from the elongate body into the handle and may include a suction port 197 at the proximal end.
  • the apparatus also includes a controller 115 that couples or connects (via a connector 187 to each of the electrodes including the electrodes on or around the aspiration opening.
  • the controller in this example may include one or more outputs (e.g., display/LED, lights, tone/sound, etc.).
  • the controller may indicate (visually, audibly, etc.) the nature of the material is adjacent to, on or in the distal end of the suction lumen and/or at the aspiration opening.
  • the controller may process impedance signals using the sensing subsystem 117 as described herein, including applying energy, e.g., current, to the electrodes and sensing impedance to generate a data stream, which may be an ongoing data stream, and determining from the data stream the one or more classification states based on the ongoing data stream as described herein.
  • energy e.g., current
  • the sensing sub-system may include control logic, memory and/or one or more processors (or may access the one or more processor of the controller 115) to determine if the electrodes (and therefore the distal end region of the catheter and/or the aspiration opening region, is in contact with air, saline, blood, in contact with or near non-blood tissue, in contact or near clot material, in contact with or near vessel wall, etc.
  • the sensing sub-system may be part of or separate from the controller and/or a removal (e.g., suction-controlling) sub-system 119.
  • the sensing subsystem, controller and/or removal sub-system may include one or more processors or may share one or more processors.
  • a processor includes hardware that runs software (e.g., computer program code).
  • the term ‘processor’ may include or be part of a controller and may encompass not only computers having different architectures such as single/multi-processor architectures and sequential (Von Neumann)/parallel architectures but also specialized circuits such as field-programmable gate arrays (FPGA), application specific circuits (ASIC), signal processing devices and other devices.
  • FPGA field-programmable gate arrays
  • ASIC application specific circuits
  • the controller (and/or the sensing sub-system) may output and indicate the catheter tip conditions described above, and/or impedance information from the ongoing data stream.
  • the impedance information may be ‘raw’ or modulated (e.g., filtered, smoothed, etc.).
  • the output of sensing sub-system may be analyzed, stored, transmitted, etc.
  • the controller may also control the operation of clot removal, including the application of aspiration through the aspiration lumen and distal aspiration opening, e.g., using the removal sub-system 119, which may include one or more aspiration sensors (e.g., sensing the application of aspiration) and/or pumps, switches, etc.
  • the methods and apparatuses described herein may generate an impedance data stream using some or all of the electrodes of the device in order to analyze the impedance data stream to determine a state at the catheter tip.
  • the impedance data stream may be generated and monitoring, sensed, recorded, etc. in real time or near real-time.
  • the impedance data stream may be a continuous (ongoing for a fixed or variable amount of time) or discrete data stream, or in some examples an intermittent impedance data stream.
  • the impedance data stream may measure impedance between or at the electrodes (‘sensing electrodes’ or ‘impedance sensing electrodes’) by applying energy (e.g., a test current, voltage, etc.), and may detect a response electrical signal such as impedance or one or more electrical properties that are related to impedance, or from which impedance may be derived (e.g., resistance, voltage, current, etc.), the impedance signal may be a complex impedance data stream (e.g., including magnitude and phase) and may be applied at two or more frequencies (including but not limited to a spectrum of frequencies).
  • energy e.g., a test current, voltage, etc.
  • the impedance signal may be a complex impedance data stream (e.g., including magnitude and phase) and may be applied at two or more frequencies (including but not limited to a spectrum of frequencies).
  • the impedance data stream (“data stream”) may be used to identify/classify the catheter tip conditions/environments described herein.
  • the methods and apparatuses described herein may be configured to perform an analyses on the impedance data stream, including determining/estimating one or more indicator form the data stream.
  • the impedance data stream may be monitored as a signal waveforms and input to the sensing sub-system as described. These methods and apparatuses may determine the 10%- 90% rise time of the impedance vs. time waveform within a window (e.g., time window) of the impedance data stream.
  • the methods and apparatuses may determine a slope (e.g., rate of change) of the impedance magnitude vs.
  • the methods and apparatuses may determine a maximum impedance magnitude within a window (e.g., a time window).
  • the methods and apparatuses may determine a minimum impedance magnitude within a window (e.g., a time window).
  • the methods and apparatuses may determine a variability of the impedance magnitude within a window of time.
  • Other indicator may be used instead or in addition.
  • the time window for analyzing (e.g., determining the indicator from) the data stream may be dynamic. Specifically, the time window may be made larger or smaller depending on the operational state and/or sensing state of the apparatus. For example, the size of the time window for the impedance data stream may be changed based on the impedance value(s) sensed. For example, when clot is identified, the apparatus may reduce the size of the window, which may result in increasing the sensitivity of the apparatus. In some cases, the apparatus may be configured to adjust the time window to adjust the sensing thresholds based on the application of aspiration.
  • the apparatus may switch sensing thresholds by adjusting the timing window so the apparatus can have a larger window for impedance monitoring when tracking through the vessel as compared with the size of the window for impedance monitoring when aspiration is activated.
  • This switch can happen using a switch/sensor at the aspiration valve or by monitoring vacuum.
  • the methods and apparatuses may determine the closeness of impedance magnitude waveform shape to a known template using methods such as a matched filter in which the impedance magnitude is correlated with various templates having signatures associated with different tissue types or events.
  • the template may be mean-normalized such that the mean value of the template is zero.
  • the input impedance magnitude data stream may be mean-normalized such that the mean of the impedance magnitude data stream in the window is approximately zero.
  • Any of these methods and apparatuses may determine deviation(s) from a maximum impedance magnitude within a window of time, and/or deviation(s) from a minimum impedance magnitude within a window of time.
  • any of these methods and apparatuses may determine a filtered impedance magnitude.
  • the impedance magnitude waveform may be filtered for noise using any appropriate time domain filters (e.g. mean filter, median filter, etc.) or frequency domain filters (e.g. low-pass filter, band-pass filter, etc.).
  • any of these methods and apparatuses may determine and store as a reference (which may be updated as a running value) a maintenance value, or baseline value, of the lowest blood-impedance measured. For example, these methods and apparatuses may track, in an ongoing manner, a current baseline corresponding to the lowest value of the impedance over a window of time; this ongoing baseline may be based on a filtered value, average value, etc.
  • the methods and apparatuses may determine or track variations first and/or second derivative of the impedance values over time, and/or within a time window. Thus, any of these methods and apparatuses may determine if the rate of change of the impedance is positive, negative and/or a magnitude of the rate of change. For example, the methods and apparatuses may determine a sign or variation in the derivative of impedance magnitude and/or phase.
  • the parameters determined from the impedance data stream discussed above may be used to directly or indirectly determine the state of the distal end region (e.g., aspiration opening) relative to clot material, blood, tissue, etc. This may be performed using one or more deterministic models and/or one or more artificial intelligence agents (e.g., using a trained neural network, deep learning agent, etc.). In some examples, the methods and apparatuses may employ a machine learning agent to aid in discerning waveform signatures leading to correct identification of environment classifications described above.
  • Table 1 describes one example of the use of these data analysis methods to identify the catheter tip conditions previously identified, for the case of using electrical impedance from a pair of electrodes placed on the rim of an aspiration orifice similar to that shown in FIG. 1.
  • the methods and apparatuses described herein may be configured to use the impedance data stream (raw, or in some cases, pre-processed) as input to determine any of the “states” for the end of the catheter (e.g., the region adjacent to the sensing electrodes).
  • the states may also be referred to as tissue classifications, and may include: one or more electrodes in contact with air; one or more electrodes in contact with saline; one or more electrodes in contact with blood; one or more electrodes in contact with or near blood clot; one or more electrodes embedded in blood clot; one or more electrodes in contact with or near vessel wall (tissue); the aspiration of clot passing by (touching or near) one or more electrodes; one or more electrodes latching onto vessel wall; one or more electrode in contact with fluoroscopy contrast injection; estimation of the diameter of a vessel in which the electrodes are located; and/or identification of System/Sensing error.
  • the thresholds determined may be fixed or adaptive based on measurements made (e.g., in the patient).
  • the window of time may be the same for each of these techniques for analyzing the impedance data streams described herein. In some case the window of time may be constant or adjustable.
  • the window of time may be preset or user set.
  • the thresholds may use impedance magnitude and/or phase information.
  • the thresholds may include hysteresis to help prevent noise fluctuations from erratic interpretation.
  • the identification of tissue and fluids may include saline, blood, and air.
  • the position of the electrode may be on or near the distal end region of the catheter, thus the electrode is a proxy for the distal end region of the catheter (e.g., the region near the aspiration opening).
  • FIG. 2 illustrates one example of a method of determining tissue type and/or fluid (e.g., blood, saline, clot, vessel, etc.).
  • the method or apparatus utilizes the impedance magnitude and phase vs. time waveform to identify the catheter tip conditions above.
  • the schematic illustrates determining a tissue type/fluid type. This may include determining if the electrode are in saline, blood, near or against clot and/or embedded in clot (e.g., state classifications A-D or A-E).
  • Clot may be considered detected when the impedance magnitude exceeds a known rising clot impedance threshold, but still resides below a higher threshold.
  • the environment may be considered clear of clot when the impedance magnitude drops below the falling clot impedance threshold.
  • the difference between the rising and falling clot impedance threshold adds hysteresis to the system preventing unwanted rapid switching between the clot and nonclot state.
  • FIG. 3 illustrates one example of a clot detection flow chart.
  • the impedance magnitude may be used to determine the one more tip conditions (e.g., may determine some or all of the state classification).
  • FIG. 4 illustrates an example of the magnitude order for various states based on the magnitude of their impedance values.
  • the change in the impedance data stream parameters over time may also be used to identify one or more states of the region around the electrodes, e.g., the catheter tip.
  • an impedance magnitude vs. time waveform may have a distinct signature that can be used to identify the wall latch.
  • This signature can be detected by using a matched filter in which the impedance magnitude is correlated with a “latch template” also having the wall latch signature.
  • the matched filter may be implemented by taking the dot product of the “latch template” and the impedance magnitude data stream. A threshold may then be implored on the result of this dot product, as a measure of how well the data stream matches the template.
  • FIGS. 7D-7G illustrate another example of a matched filter detection of the wall latch signature.
  • FIG. 7D shows an impedance magnitude waveform
  • FIG. 7E shows a level- shifted impedance magnitude waveform
  • FIG. 7F shows a latch template
  • FIG. 7G shows the dot product.
  • the impedance of blood clot in a particular patient may scale with the blood impedance in that patient.
  • a person with a high impedance blood may be likely to have higher-impedance blood clot, for example. So, a measurement of the patient’s blood impedance can be used to scale the thresholds for determining clot in that patient.
  • the methods and apparatuses described herein may be adaptive for each patient. Examples of such adaptive behavior may include: clot threshold (upper and/or lower threshold) may be equal to a fixed offset from that patient’s blood impedance, and/or fixed scale-factor of that patient’s blood impedance.
  • the methods and apparatuses described herein may determine a “blood baseline” by estimating the unimpeded blood magnitude. These methods and apparatuses may maintain the lowest blood measurement seen, so that as the catheter is introduced into the body, the blood measurement may be saved, which may be taken with the largest volume of blood around the catheter tip.
  • these methods and apparatuses may include other characteristics which help ensure the methods and apparatuses do not get “fooled” by noise or other non-blood activities.
  • These methods and apparatuses may include an average impedance over a small moving time-window that may be used to help filter noise spikes.
  • the impedance may be constrained within the blood-range impedance bounds (low and high) known for blood.
  • These methods and apparatuses may be configured to have a low- variation (max -min) over a certain time-duration to show a steady value is maintained to be considered a good blood-measurement. In some examples, these methods and apparatuses may constrain the impedance to be lower than previously measured blood-baseline.
  • FIG. 8A illustrates one example of a detection and monitoring of impedance magnitude over time that may be used to determine a blood impedance baseline.
  • a “local blood value” or “current blood” value may be determined.
  • These methods and apparatuses may capture the impedance of blood in a vessel which can vary both up and down as different vessels are traversed.
  • these methods and apparatuses have found that even when just blood is in contact with the electrodes at the tip of a catheter, the smaller the vessel the higher that blood impedance measurement will be. So, a value for what blood impedance measures in the current vessel may be used to better interpret what is happening when things other than blood are in contact with the tip electrodes.
  • FIG. 8B shows another example of a graph showing the unfiltered impedance magnitude of blood and the running baseline.
  • the average impedance over a small moving time-window may be used to help filter noise spikes.
  • the impedance may be constrained to be within the blood-range impedance bounds (low and high) known for blood.
  • the impedance waveform may be constrained to have low-variation (max-min) over a certain time-duration to show a steady value is maintained to be considered a good bloodmeasurement.
  • the impedance can be less than or greater than previously measured bloodvalue.
  • the electrodes may be configured as electrochemical impedance sensors (EIS).
  • EIS electrochemical impedance sensors
  • the method or apparatus may be configured to measure impedance signals by applying an AC potential to an electrochemical cell and then measuring the current through the cell.
  • a sinusoidal potential excitation may be applied, and the response to this potential is an AC current signal.
  • FIG. 9 illustrates one example of an equivalent circuit model for tissue.
  • the EIS measurements can be used to perform an equivalent circuit model parameter extraction. The resulting parameters can be used in classification of the environment categories as described above.
  • Electrochemical Impedance Spectroscopy results in complex impedance data between two or more electrodes whereas potentiometric/amperometric analysis results in potential across/current through two or more electrodes.
  • EIS Electrochemical Impedance Spectroscopy
  • the methods and apparatuses described herein may accurately sense when the aspiration catheter tip (including the sensing electrodes) is in proximity to clot material and this information may be used to automatically control the aspiration of that clot out of the body. These methods and apparatuses may signal when the aspiration orifice is in contact with clot, for instance, to drive an electro-mechanical interface to perform aspiration. That interface (e.g., a removal sub-system as described in FIG. 1) may include a valve into a vacuum chamber, or a motor drive to pull suction (e.g., a pump).
  • the methods and apparatuses may signal to turn on aspiration e.g., when the catheter contacts clot, and/or turn off aspiration, e.g., when the catheter tip is no longer in contact with clot.
  • This mechanism of operation may allow for the most efficient use of aspiration to only extract blood clots and may minimize blood loss.
  • This automatic aspiration control may be enabled/disabled by the user of the device.
  • FIGS. 10A-10B schematically illustrate examples of such an apparatus that includes an aspiration catheter 1032 having two or more electrodes 1032, 1032’ configured to sense impedance and provide an impedance data stream for detecting clot 1030, blood, tissue (e.g., vessel wall), air, etc.
  • an aspiration catheter 1032 having two or more electrodes 1032, 1032’ configured to sense impedance and provide an impedance data stream for detecting clot 1030, blood, tissue (e.g., vessel wall), air, etc.
  • tissue e.g., vessel wall
  • air e.g.
  • the apparatus 1000 may control aspiration generally, e.g., when the system 1000 senses clot material (or a transition from blood and/or wall to clot) on one or more sensors (e.g., electrodes 1032, 1032’) on the catheter, such as on the aspiration opening of the catheter, the controller (e.g., control circuitry, including one or more processors 1038) may switch on aspiration.
  • the controller 1038 may be part of the handle 1035 and/or may be coupled to the handle, wirelessly and/or via one or more cables/wires.
  • the controller 1038 may be part of the local system or may be remote from the system such as part of a remote server, and the system may transmit data (e.g., the stream of impedance data) from the local system to a remote server and/or processor.
  • a system may include one or more (preferably two or more, such as one or more pairs of) electrodes 1032, 1032’ that are configured to sense impedance.
  • One or more additional sensors e.g., pressure sensors, etc. may be included.
  • the apparatus when analyzing the impedance data stream, determines that the catheter is in contact with clot material (or is adjacent to clot material), may activate aspiration from a source of aspiration 1040, e.g., by activating an on-demand aspiration power source such as a syringe pump (or just a moving syringe plunger) or by any other on- demand pump, vacuum pump, etc.
  • a source of aspiration 1040 e.g., by activating an on-demand aspiration power source such as a syringe pump (or just a moving syringe plunger) or by any other on- demand pump, vacuum pump, etc.
  • the apparatus may open one or more valves 1036 to apply aspiration, e.g., from a charged source of aspiration (e.g., suction chamber 1040’).
  • the catheter handle 1035 may include a controller 1038 (not shown in FIG.
  • valve 1036 integrated within and may control the source of aspiration including a valve 1036 opening/closing a chamber charged with vacuum 1040’ based on when clot is detected/not detected.
  • these methods and apparatuses may stop the application of aspiration either when clot is no longer detected (e.g., from the ongoing impedance data stream), and/or based on a predetermined or adjustable time after opening, and/or base on a sensed pressure within the lumen of the catheter 1032.
  • the apparatus may turn off aspiration either immediately (if above a shut-down threshold) or after a delay (e.g., if less than the shut-down threshold).
  • a predetermined threshold including when the catheter is clogged
  • the apparatus and/or method may be configured to automatic, including closed-loop, operation.
  • the apparatus and method may be configured to for semi-automatic and/or manual operation.
  • the apparatus may be configured alert the user (e.g., a medical care provider, such as a nurse, medical technician, physician, surgeon, doctor, etc.) so that the user may confirm and/or prevent turning on and/or off of the aspiration or other components based on detection of a clot material at or near the aspiration opening of the catheter.
  • the apparatus may be configured to trigger turning on and/or off after a waiting period to allow the user to confirm/reject the action.
  • the apparatus may display that a clot, tissue (e.g., wall), air and/or blood has been detected using one or more of the high-confidence detection techniques and apparatuses described herein.
  • the apparatus may output an indicator of the material detected from the impedance data stream (and in some cases one or more secondary sensors) confirming the material at or near the aspiration opening of the catheter.
  • this output may be a display or other indicator, such as one or more LEDs showing a color corresponding to the identified material (clot, wall, blood, air, etc.).
  • the output may be visual (text, color, symbol, etc.) and/or audible (e.g., a tone, etc.).
  • any of these apparatuses may include one or more additional sensors, including pressure sensors (e.g., detecting pressure within the aspiration source, within the lumen of the catheter), contact/force sensors, optical sensors or the like, that may be used to refine the analysis of the impedance data stream to further confirm if/that the distal end region of the catheter (and/or the aspiration opening) is in adjacent and/or in contact with clot, wall (e.g., tissue), blood, air, etc., particularly in one or more predetermined states, such as when the rate of change of the impedance data stream is greater than a rate of change threshold, when the magnitude of the impedance data stream is greater than an impedance magnitude upper threshold, or is less than an impedance magnitude lower threshold, or when the phase is outside of a predetermine range of phase values.
  • pressure sensors e.g., detecting pressure within the aspiration source, within the lumen of the catheter
  • contact/force sensors e.g., detecting pressure within the aspiration source, within
  • these apparatuses may include one or more sensors that may detect operational states of the system, including the catheter, aspiration source, etc. that may also be used by the controller to control operation of the apparatus.
  • the apparatus may include a sensor detecting the operational state of the aspiration source (e.g., no aspiration, open aspiration chamber, etc.) and may emit one or more alerts and/or may prevent operation of the apparatus in one or more states (e.g., source of vacuum not ready, etc.).
  • any of these apparatuses may include a pump to provide suction (e.g., aspiration) through the catheter.
  • the pump system e.g., aspiration sub-system
  • the pump system may include one or more sensors that may provide input to the controller for controlling operation of the apparatus.
  • a piston-driven pump e.g., a syringe pump, etc.
  • a position e.g., encoder
  • This data may be used to control overall operation of the system, as mentioned, and/or may provide data that may be used to determine that the distal end region (and/or aspiration opening) of the catheter is in contact with or adjacent to clot, wall, blood, air, etc.
  • data indicating that the pump is actively applying pressure through the catheter which may be indicated by pressure sensors on the pump and/or catheter, or one or more position sensors indicating an operation of the pump (e.g., piston pump, or other drive member).
  • This information e.g., the status of the pump, in addition to data from the impedance data stream, may distinguish between clot, wall, blood, air, etc.
  • the apparatus or method may only classify wall latch (e.g., wall at or near the distal tip) if the pressure indicates that vacuum is being applied.
  • the controller may be configured to detect a rapid change in pressure (e.g., form a pressure or pump sensor) such as a positive pressure spike, which may identify and/or help classify contrast injection during operation of the apparatus.
  • a rapid change in pressure e.g., form a pressure or pump sensor
  • the pressure e.g., sensed from a pressure sensor, may exceed a pressure threshold if the system is clogged; thus these apparatuses and methods may be configured to detect clogging based at least in part on sensed pressure.
  • pressure e.g., sensed pressure
  • the use of pressure may be used in combination with the impedance data stream to identify one or more system errors, and/or to trigger one or more user actions required, such as (but not limited to), identifying and/or notifying that aspiration/pump is low on power (e.g., low on charged vacuum), that a return line restricted, etc.
  • the methods and apparatuses described herein may include electrodes in any appropriate region.
  • the electrodes 1132 may be at or on the aspiration opening.
  • the electrodes may be distal to the aspiration opening.
  • a pair of electrodes 1133 are located distal to the aspiration orifice 1125. This location of electrodes may provide information about clot-presence in a vessel in regions distal to the orifice, which may help inform where best to place the catheter to perform aspiration / clot extraction.
  • the aspiration opening is shown on a side (e.g., a tapered side) of the distal end region of the catheter.
  • the aspiration opening may be on the distal face of the catheter (e.g., eri face).
  • the electrode may be fluish, recessed and/or may extend proud of the aspiration opening and/or outer surface of the catheter.
  • the best location to extract clot may not be with the aspiration orifice embedded into the clot but instead could be several millimeters back from the clot itself, in order to allow some initial blood flow to come into the catheter orifice and help agitate and move the clot through the catheter lumen without clogging. If the distance from the orifice to the clot is too close (e.g., 0 mm, less than 1 mm, less than 2 mm, etc.) there could be restricted flow and possible clogging.
  • One apparatus design may include a catheter which has a pair of electrodes on the aspiration orifice, but one or more additional electrodes on a region of the catheter tip more distal than the aspiration orifice, as shown in FIG. 11, such that information regarding clot-touching is available at both locations.
  • the user could use the two independent sensing signals to appropriately place the catheter prior to aspiration.
  • the catheter could be advanced in a vessel until just the distal electrodes provide a clot signal and the rimelectrodes still show blood-exposure, for instance.
  • the catheter could be advanced until both sets of electrodes detected clot-contact, and then the catheter slowly backed up until the rim-electrodes again sensed blood, but the distal electrodes still sensed clot. Either way the catheter may be placed in an optimal location for clot extraction.
  • the distal electrodes may be a pair (as shown) or may be a single electrode with respect to a further reference electrode.
  • FIGS. 12A-12C illustrate one example of the detection that the electrodes (e.g., the distal tip of the catheter) is in air.
  • the apparatus or method may determine the “air seen” condition (mode).
  • FIG. 12A shows the unfiltered magnitude of the impedance sensed.
  • FIG. 12B shows the mean filtered impedance magnitude.
  • FIG. 12C shows an example of the zoomed-in filtered impedance magnitude showing "air seen" approximately 100 ms after remaining in the "air seen" threshold limits for 100 ms.
  • FIG. 14 shows an example of the detection of “High-Z” condition using the methods and apparatuses described herein.
  • the impedance exceeds a threshold of 80 kQ and stays in this Hi-Z range (> 80 kQ) for more > 100 ms, resulting in the determination by the apparatus or method that the electrodes (e.g., the distal end of the catheter) is in a high-impedance (High-Z) state, which may be used by the apparatus or method to indicate a state classification (e.g., within clot, etc.).
  • FIG. 15 shows an example of the detection of “Low-Z” condition using the methods and apparatuses described herein.
  • the impedance falls below 100 Q and stays in Low-Z range (e.g., ⁇ 100 Q) for more > 100 ms, resulting in the determination by the apparatus or method that the electrodes (e.g., the distal end of the catheter) is in a low- impedance (Low-Z) state, which may be used by the apparatus or method to indicate a state classification.
  • Low-Z low- impedance
  • FIG. 16 is a graph illustrating that the baseline has been detected using the mean filtered impedance.
  • the “baseline detected” condition may be determined as the impedance falls below 1300 Q for one sample.
  • FIG. 17 is a graph illustrating that the “change mind” condition (e.g., indication a likely change in the state condition) using the filtered impedance magnitude.
  • the impedance rises above 2750 Q for one sample.
  • FIG. 18 graphically illustrates the detection of clot (e.g., the clot contact condition).
  • clot e.g., the clot contact condition
  • the mean filtered impedance rises above a “clot detected” threshold, e.g., 37 samples ago (a predetermined or adjustable delay). The delay may be used to give the “latch detected” condition a chance to be seen.
  • the methods and apparatuses described herein may use other techniques for determining clot threshold, which may be fixed (predetermined), settable or adjustable.
  • the clot threshold may be a multiple of the blood baseline.
  • the clot threshold may be a (programmable) fixed offset above the blood baseline.
  • FIGS. 19A-19E illustrate another example of latch detection, e.g., showing parameters that may be used for determining the “latch detected” condition.
  • FIG. 19A shows the unfiltered impedance magnitude waveform.
  • FIG. 19B shows the mean filtered impedance waveform.
  • Fig. 19C shows the dot product of unfiltered impedance magnitude with template.
  • FIG. 19D shows the maximum sample in the last 75 samples.
  • FIG 19E shows the maximum single point jump in the last 75 samples.
  • the methods and apparatuses described herein may also be configured to determine what type of blood clot is on or near the electrodes based on the electrical impedance values, including based on the impedance data stream.
  • the electrical properties of clot material may depend on the composition and structure of the clot, and may be based on the age, composition of fibrin, platelets, and red blood cells in the clot. These variations can result in differences in their electrical properties, including impedance.
  • impedance spectroscopy techniques may be used, including measuring impedance across a range of frequencies. Different clot types may exhibit unique impedance spectra due to variations in their cellular and structural compositions.
  • Impedance spectroscopy can provide detailed information about the clot's properties at different frequencies.
  • the impedance-based apparatuses described herein may detect and differentiate clot types based on the impedance patterns; by analyzing the impedance data stream obtained from these sensors, it's possible to categorize clots into types such as fibrin-rich, platelet-rich, or red blood cell-rich clots.
  • the ability to identify different clot types through impedance analysis may improve clinical diagnostics and treatment.
  • the methods described herein may provide a standardized technique for measurements and/or for interpretations of otherwise complex impedance data.
  • the methods and apparatuses described herein may be configured to detect a side branch of the pulmonary vasculature that is occluded with clot.
  • the branches of the vasculature may be so occluded that even contrast injections do not show the existence of the side branch, or where the entrance is located. This may result in incomplete removal of clot material.
  • the methods and apparatuses described herein may be capable of, and in some cases adapted for, detection of occluded, including fully occluded, side branches. This information may allow for catheter tip placement for extraction of the clot material occluding the branch. Sensing the clot at the entrance to such an occluded vessel may allow the user to identify where that vessel is located and perform extraction.
  • procedure for removing clot material may include using a sensing/aspiration catheter to described herein to identify an occluded vessel and performing thrombectomy by aspirating the clot material from the occluded vessel.
  • These methods may include orienting one or more sensors (e.g., electrodes, including electrode pairs) on the distal end region of the device towards and/or against the vessel wall.
  • the sensing electrodes may the sensing electrodes described above, e.g., on the distal end region, including on the periphery of the aspiration opening or proximal and/or distal to the aspiration opening, or opposite the aspiration opening (on the radially opposite side of the aspiration opening).
  • the apparatus may include with one or more additional sensing electrodes or electrode pairs that are positioned on a side-facing region portion.
  • the sensing electrodes may be configured to be held against the wall of the vessel as the apparatus is moved within the vessel.
  • the apparatus may include a bending region and the electrodes may be located on an outer region of this bending region, so that the electrodes are positioned against the wall when the bending region is bent or curved.
  • the sensing electrode(s) may be on a radially expandable region that may position the electrodes against the wall.
  • the electrode(s) may be moved with the catheter along the vessel wall to see if clot is sensed. This sliding may be done in either direction (e.g., towards a more distal location and/or towards a more proximal location).
  • the tapered shape of the distal tip may be advantageous, as it may act as its own dilator.
  • the apparatuses described herein may be configured to scan for side branches as the device is advanced and/or retracted.
  • the controller may be configured to, on an ongoing basis, examine the electrical properties of the side-facing electrode(s) that are presumed to be in contact with the wall of the vessel and may indicate when the electrical signal is within the range of clot material, potentially indicating a side branch that is occluded.
  • the controller may be configured to scan automatically or semi -automatically (e.g., assisting the user in directing movement of the distal end region of the device).
  • FIGS. 21 and 22 illustrate examples of determining the state (e.g., the state classification indicator) indicating contact of the distal end region of a catheter with one of: blood, clot, vessel wall, air, saline, etc.
  • the method may first receive an impedance data stream from one or more electrodes on a distal end region of a catheter 2101. Any of these methods may include estimating, in an ongoing basis, a first indicator from the impedance data stream 2103.
  • this first indicator may be, e.g., a magnitude of the impedance (at a current time point or window of time), a phase of the impedance (at a current time point or window of time), or a rate of change of the impedance.
  • the method may determine which type of second indicator to estimate/measure in order to disambiguate the state as suggested by the first indicator. For example, if the first indicator is a magnitude of the impedance (in some cases an average, peak, median, etc. of the impedance) is within one or a number of ranges, a different second indicator may be used to disambiguate the state.
  • the first indicator is a magnitude of the impedance (in some cases an average, peak, median, etc. of the impedance) is within one or a number of ranges
  • a different second indicator may be used to disambiguate the state.
  • the apparatus may determine that the second indicator should be one that distinguishes blood clot from air (e.g., phase, the rate of change, a variability of the impedance, a rise time of the impedance, etc.) or may be a from an alternative sensing technique, such as pressure, optical, etc.).
  • the second indicator is not limited to being derived from the impedance data stream but may be an alternative sensing technique.
  • the method may then, based on the value of the first indicator, may estimate a second indicator (e.g., from the impedance data stream or an alternative sensor) 2105.
  • the second indicator is generally a different indicator type than the first indicator.
  • the second indicator may be: a magnitude of the impedance, a phase of the impedance, a rate of change of the impedance, a variability of the impedance, a rise time of the impedance, a maximum impedance magnitude within a window of time, a minimum impedance magnitude within the window of time, and/or a shape of impedance data stream over time, etc.
  • the value of the first indicator may therefore provide an initial or rough estimate of the state and the second indicator may confirm or refine the estimate.
  • This estimate of the state may be determined from both the first and second indicators using a look-up table or series of look-up tables, and/or a trained machine learning agent.
  • the state classification indicator may indicate the material that the distal end region of the catheter is in contact with (e.g., a material consisting of one of: air, clot, vessel wall, blood and saline) 2107.
  • FIG. 22 illustrate another example of a method as described herein.
  • the method may again begin with a received impedance data stream from one or more electrodes (e.g., a pair of electrodes) 2201.
  • multiple impedance data streams may be received (e.g., by a processor either local and/or remote); in some cases a second or more impedance data stream may provide a baseline that may be used, e.g., for normalizing the primary impedance data stream and/or any indicators determined therefrom.
  • a first indicator may be estimated from the impedance data stream 2203.
  • the first indicator may be a magnitude estimate, as mentioned above.
  • the first indicator is a phase estimate and/or a complex impedance estimate.
  • the first estimate is a rate of change estimate.
  • the first indicator may then be compared to a first plurality of ranges; the ranges are matched to the indicator type.
  • the indicator may be a rate of change of impedance having four range categories: positive and greater than a first threshold value, positive and less than the first threshold value, negative and greater than the first (or a second) threshold value and negative and less than the first (or the second) threshold value.
  • the indicator may be a magnitude as mentioned above, and may have five categories (corresponding to percentages of the dynamic range of magnitudes, as shown in FIG. 4, e.g., greater than 85%, between 50%-85%, between 30%-50%, between 15-30%, less than 15%).
  • the value within the ranges may indicate or suggest a particular state, and may also inform the selection of the second indicator.
  • a second indicator may be estimated (e.g., from the impedance data stream or an alternative sensing technique) 2207.
  • the second indicator is different from the first indicator and may include, for example: the magnitude, the phase, the rate of change, a variability of the impedance, a rise time of the impedance, a maximum impedance magnitude within a window of time, a minimum impedance magnitude within the window of time, and/or a shape of impedance data stream over time.
  • the second indicator may then be compared (e.g., using a look-up table and/or trained machine learning agent, as mentioned above) to a range of values to determine, in some cases in combination with the first indicator, the state of the state classification indicator 2209.
  • the method may then output the state classification indicator 2211 indicating what material that the distal end region of the catheter is in contact with (e.g., air, clot, vessel wall, blood and saline).
  • an error state may be generated, if the first and second indicators conflict or fail to converge on a particular material.
  • any of the methods (including user interfaces) described herein may be implemented as software, hardware or firmware, and may be described as a non-transitory computer-readable storage medium storing a set of instructions capable of being executed by a processor (e.g., computer, tablet, smartphone, etc.), that when executed by the processor causes the processor to control perform any of the steps, including but not limited to: displaying, communicating with the user, analyzing, modifying parameters (including timing, frequency, intensity, etc.), determining, alerting, or the like.
  • any of the methods described herein may be performed, at least in part, by an apparatus including one or more processors having a memory storing a non-transitory computer-readable storage medium storing a set of instructions for the processes(s) of the method.
  • FIG. 20 schematically illustrates one example of a method for detecting (e.g., identifying) a side branch within a vessel.
  • the method may include moving a catheter within a vessel (e.g., advancing and/or retracting) 2001.
  • the method may include using one or more guidewires, guide/navigation catheters, etc. and may include using fluoroscopy to image movement and assist in guidance.
  • any of these methods may include positioning one or more sensing electrodes near the vessel wall (e.g., bending the catheter, radially extending a support supporting the sensing electrodes, etc.) 2003. This step may be performed before and/or while moving the catheter.
  • the method may further include sensing and determining the type of tissue adjacent to the sensing electrode(s), e.g., using an impedance data stream to determine one or more of: impedance magnitude, rise time waveform, slope (e.g., rate of change) of the magnitude over time, maximum impedance value within a window of time, variability of the impedance magnitude within a window of time, comparing the magnitude waveform of the impedance to a library of known waveforms, etc. 2005.
  • the characterization of the tissue may be used to identify a side branch in the vessel based on the type of tissue adjacent to the sensing electrode(s) 2007.
  • One identified the side branch may be examined (e.g., navigated, characterized, etc.).
  • the method and/or apparatus may identify if the side branch is occluded (e.g., by clot material). If so, the method may further include removing clot material from the side branch 2009. For example, the method ma include aligning the aspiration opening and applying suction, etc.
  • the computing devices and systems described and/or illustrated herein broadly represent any type or form of computing device or system capable of executing computer-readable instructions, such as those contained within the modules described herein. In their most basic configuration, these computing device(s) may each comprise at least one memory device and at least one physical processor.
  • the term “memory” or “memory device,” as used herein, generally represents any type or form of volatile or non-volatile storage device or medium capable of storing data and/or computer-readable instructions. In one example, a memory device may store, load, and/or maintain one or more of the modules described herein.
  • RAM Random Access Memory
  • ROM Read Only Memory
  • HDD Hard Disk Drives
  • SSDs Solid-State Drives
  • optical disk drives caches, variations or combinations of one or more of the same, or any other suitable storage memory.
  • processor or “physical processor,” as used herein, generally refers to any type or form of hardware-implemented processing unit capable of interpreting and/or executing computer-readable instructions.
  • a physical processor may access and/or modify one or more modules stored in the above-described memory device.
  • Examples of physical processors comprise, without limitation, microprocessors, microcontrollers, Central Processing Units (CPUs), Field-Programmable Gate Arrays (FPGAs) that implement softcore processors, Application-Specific Integrated Circuits (ASICs), portions of one or more of the same, variations or combinations of one or more of the same, or any other suitable physical processor.
  • the method steps described and/or illustrated herein may represent portions of a single application.
  • one or more of these steps may represent or correspond to one or more software applications or programs that, when executed by a computing device, may cause the computing device to perform one or more tasks, such as the method step.
  • one or more of the devices described herein may transform data, physical devices, and/or representations of physical devices from one form to another. Additionally or alternatively, one or more of the modules recited herein may transform a processor, volatile memory, non-volatile memory, and/or any other portion of a physical computing device from one form of computing device to another form of computing device by executing on the computing device, storing data on the computing device, and/or otherwise interacting with the computing device.
  • computer-readable medium generally refers to any form of device, carrier, or medium capable of storing or carrying computer-readable instructions.
  • Examples of computer-readable media comprise, without limitation, transmission-type media, such as carrier waves, and non-transitory-type media, such as magnetic-storage media (e.g., hard disk drives, tape drives, and floppy disks), optical-storage media (e.g., Compact Disks (CDs), Digital Video Disks (DVDs), and BLU-RAY disks), electronic-storage media (e.g., solid-state drives and flash media), and other distribution systems.
  • transmission-type media such as carrier waves
  • non-transitory-type media such as magnetic-storage media (e.g., hard disk drives, tape drives, and floppy disks), optical-storage media (e.g., Compact Disks (CDs), Digital Video Disks (DVDs), and BLU-RAY disks), electronic-storage media (e.g., solid-state drives and flash media),
  • the processor as described herein can be configured to perform one or more steps of any method disclosed herein. Alternatively or in combination, the processor can be configured to combine one or more steps of one or more methods as disclosed herein.
  • the device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
  • the terms “upwardly”, “downwardly”, “vertical”, “horizontal” and the like are used herein for the purpose of explanation only unless specifically indicated otherwise.
  • first and second may be used herein to describe various features/elements (including steps), these features/elements should not be limited by these terms, unless the context indicates otherwise. These terms may be used to distinguish one feature/element from another feature/element. Thus, a first feature/element discussed below could be termed a second feature/element, and similarly, a second feature/element discussed below could be termed a first feature/element without departing from the teachings of the present invention.
  • any of the apparatuses and methods described herein should be understood to be inclusive, but all or a sub-set of the components and/or steps may alternatively be exclusive and may be expressed as “consisting of’ or alternatively “consisting essentially of’ the various components, steps, sub-components or sub-steps.
  • all numbers may be read as if prefaced by the word "about” or “approximately,” even if the term does not expressly appear.
  • a numeric value may have a value that is +/- 0.1% of the stated value (or range of values), +/- 1% of the stated value (or range of values), +/- 2% of the stated value (or range of values), +/- 5% of the stated value (or range of values), +/- 10% of the stated value (or range of values), etc.
  • Any numerical values given herein should also be understood to include about or approximately that value, unless the context indicates otherwise. For example, if the value " 10" is disclosed, then “about 10" is also disclosed.
  • any numerical range recited herein is intended to include all sub-ranges subsumed therein. It is also understood that when a value is disclosed that “less than or equal to” the value, “greater than or equal to the value” and possible ranges between values are also disclosed, as appropriately understood by the skilled artisan. For example, if the value "X” is disclosed the “less than or equal to X” as well as “greater than or equal to X” (e.g., where X is a numerical value) is also disclosed. It is also understood that the throughout the application, data is provided in a number of different formats, and that this data, represents endpoints and starting points, and ranges for any combination of the data points.

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Abstract

Procédés et appareils de surveillance électrique, comprenant la surveillance d'impédance électrique, à l'aide d'électrodes positionnées sur un cathéter pour permettre d'identifier le type de matériau en contact avec le cathéter. En particulier, sont décrits dans la description des procédés et des appareils pour utiliser des flux de données d'impédance pour identifier un matériau qui peut être rencontré lors de la réalisation d'une intervention vasculaire comprenant : un matériau de caillot, du sang, une solution saline, de l'air et/ou une paroi de vaisseau, par analyse et classification de conditions d'impédance. Sont également décrits dans la description des procédés de sondage électrique et/ou mécanique de la zone locale autour du cathéter (p. ex., la pointe d'un cathéter d'aspiration) pour permettre de caractériser les conditions et les matériaux environnants.
PCT/US2025/013045 2024-01-24 2025-01-24 Procédés et appareils de détection électrique de caillot sanguin Pending WO2025160472A1 (fr)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150011856A1 (en) * 2013-07-03 2015-01-08 Saranas, Inc. Bleed detection technique
US20200188016A1 (en) * 2005-12-06 2020-06-18 St. Jude Medical, Atrial Fibrillation Division, Inc. System and method for assessing lesions in tissue
US20200281648A1 (en) * 2014-11-19 2020-09-10 Epix Therapeutics, Inc. Electrode assembly with thermal shunt member
WO2022261448A1 (fr) * 2021-06-10 2022-12-15 Shifamed Holdings, Llc Systèmes de retrait de thrombus et procédés associés
US20230405273A1 (en) * 2021-06-28 2023-12-21 Inquis Medical, Inc. Apparatuses and methods for tracking obstructive material within a suction catheter

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20200188016A1 (en) * 2005-12-06 2020-06-18 St. Jude Medical, Atrial Fibrillation Division, Inc. System and method for assessing lesions in tissue
US20150011856A1 (en) * 2013-07-03 2015-01-08 Saranas, Inc. Bleed detection technique
US20200281648A1 (en) * 2014-11-19 2020-09-10 Epix Therapeutics, Inc. Electrode assembly with thermal shunt member
WO2022261448A1 (fr) * 2021-06-10 2022-12-15 Shifamed Holdings, Llc Systèmes de retrait de thrombus et procédés associés
US20230405273A1 (en) * 2021-06-28 2023-12-21 Inquis Medical, Inc. Apparatuses and methods for tracking obstructive material within a suction catheter

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