Search

CN-122005053-A - Coated end effector electrode for sensing and ablation

CN122005053ACN 122005053 ACN122005053 ACN 122005053ACN-122005053-A

Abstract

A medical probe may include electrodes for ablating and sensing proximity to tissue and/or monitoring electrical signals within the cardiovascular system to identify abnormal conductive tissue sites that lead to arrhythmias. The electrode may be oriented on an end effector assembly, such as a basket assembly, such that one side of the electrode is positioned to contact tissue and an opposite side is inhibited from contacting tissue. To achieve both efficient delivery of energy and high sensitivity for ECG sensing, an impedance reducing coating may be positioned on the tissue contacting side and an impedance increasing coating may be applied on the opposite side. The resistance increasing coating of the IRE electrode may be sufficiently thin to allow energy to be delivered through the coating during ablation. The RF electrode may be of sufficient mass to carry electrical energy for thermal ablation.

Inventors

  • A. Gowali
  • C.T. Bickler
  • J.T. Keith

Assignees

  • 伯恩森斯韦伯斯特(以色列)有限责任公司

Dates

Publication Date
20260512
Application Date
20251110
Priority Date
20241112

Claims (20)

  1. 1. A medical probe, the medical probe comprising: A shaft extending along a longitudinal axis; A plurality of ridges extending from a distal end of the shaft and configured to spread apart from the longitudinal axis to form an elastic basket, and A plurality of electrodes, each of the plurality of electrodes comprising: A respective conductive body circumscribing a respective ridge of the plurality of ridges; an impedance reducing coating on an outer surface of the respective conductive body such that the outer surface faces away from the longitudinal axis, and An impedance increasing coating on an inner surface of the respective conductive body such that the inner surface faces the longitudinal axis.
  2. 2. The medical probe of claim 1, wherein each electrode of the plurality of electrodes is configured to sense tissue contact and provide ablation energy.
  3. 3. The medical probe of claim 1, wherein the impedance reducing coating comprises a conductive polymer.
  4. 4. The medical probe of claim 1, wherein the impedance increasing coating comprises a ceramic.
  5. 5. The medical probe of claim 1, wherein the impedance increasing coating has a thermal conductivity of about 7W/mK to about 30W/mK.
  6. 6. The medical probe of claim 1, wherein the impedance increasing coating comprises Si 3 N 4 .
  7. 7. The medical probe of claim 1, wherein each electrode of the plurality of electrodes is configured for electrocardiogram sensing.
  8. 8. A method, the method comprising: Providing a medical probe comprising a shaft extending along a longitudinal axis, a plurality of ridges extending from a distal end of the shaft and configured to expand away from the longitudinal axis to form an elastic basket, and a plurality of electrodes each comprising a respective conductive body circumscribing a respective ridge of the plurality of ridges; applying an impedance reducing coating to an outer surface of a respective conductive body of each of the plurality of electrodes such that the outer surface faces away from the longitudinal axis, and An impedance increasing coating is applied to an inner surface of the respective conductive body such that the inner surface faces the longitudinal axis.
  9. 9. The method of claim 8, wherein applying the impedance-reducing coating comprises electrodepositing the impedance-reducing coating.
  10. 10. The method of claim 8, wherein applying the impedance increasing coating comprises aerosol depositing the impedance increasing coating.
  11. 11. The method of any of claims 8, wherein the impedance-reducing coating comprises a conductive polymer.
  12. 12. The method of any of claims 8, wherein the impedance increasing coating comprises a ceramic.
  13. 13. A system, the system comprising: A medical probe comprising a shaft, one or more ridges extending from a distal end of the shaft, and a plurality of electrodes each comprising a respective conductive body circumscribing a respective ridge of the one or more ridges, each electrode of the plurality of electrodes comprising an impedance decreasing coating on a first surface of the respective conductive body and an impedance increasing coating on a second surface of the respective conductive body, and A console comprising at least one processor and a non-transitory computer readable medium in communication with the at least one processor and including instructions thereon, which when executed by the processor, cause the console to: Sensing contact of at least a portion of the plurality of electrodes with tissue based in part on impedance measurements between one or more electrode pairs of the plurality of electrodes, and Electrical energy is provided to at least a portion of the plurality of electrodes to ablate tissue.
  14. 14. The system of claim 13, wherein the impedance measurement between the one or more electrode pairs is based at least in part on the impedance of each electrode of the one or more electrode pairs decreasing the impedance of the coating and the impedance increasing the impedance of the coating.
  15. 15. The system of claim 13, wherein the non-transitory computer readable medium has instructions included thereon that, when executed by the processor, cause the console to: The contact of at least a portion of the plurality of electrodes with tissue is sensed based in part on the impedance measurements between the one or more electrode pairs and assuming the impedance increasing coating of each electrode of the one or more electrode pairs is in contact with blood.
  16. 16. The system of claim 13, wherein the electrical energy comprises radiofrequency ablation energy.
  17. 17. The system of claim 13, wherein the impedance-reducing coating comprises a conductive polymer.
  18. 18. The system of claim 13, wherein the impedance increasing coating comprises a ceramic.
  19. 19. The system of claim 13, wherein the impedance increasing coating has a thermal conductivity of about 30W/mK.
  20. 20. The system of claim 13, wherein the impedance increasing coating comprises Si 3 N 4 .

Description

Coated end effector electrode for sensing and ablation Technical Field The present invention relates generally to medical devices, and in particular to medical probes, such as catheters, configured to sense tissue proximity and deliver ablation therapy. Background Arrhythmia, such as Atrial Fibrillation (AF), may occur when a region of cardiac tissue abnormally conducts electrical signals to adjacent tissue. This can disrupt the normal cardiac cycle and lead to arrhythmia. Certain protocols are used to treat cardiac arrhythmias, including surgically disturbing the source of the signals responsible for the arrhythmia and disturbing the conduction pathways for such signals. By selectively ablating cardiac tissue by applying energy through the catheter, it is sometimes possible to stop or alter the propagation of unwanted electrical signals from one portion of the heart to another. Many contemporaneous catheter-based ablation methods utilize Radio Frequency (RF) electrical energy to heat tissue. Cryoablation is an alternative catheter-based approach to RF ablation that uses low temperature rather than heat to disable electrical signals through tissue. Irreversible electroporation (IRE) is a recent catheter-based electrical ablation method that uses non-thermal ablation to ablate cardiac tissue. To achieve IRE, a short pulse of high voltage electrical signal is delivered to the tissue, and the electrical signal generates an unrecoverable cell membrane permeabilization. The use of multi-electrode catheters to deliver IRE energy to tissue has previously been proposed in the patent literature. Examples of systems and devices configured for IRE ablation are disclosed in U.S. patent publications No. 2021/0169550A1, no. 2021/0169567A1, no. 2021/0169568A1, no. 2021/0161592A1, no. 2021/0196372A1, no. 2021/0177503A1 and No. 2021/0186604A1, each of which is incorporated herein by reference. Areas of cardiac tissue may be mapped through the catheter to identify abnormal electrical signals. Ablation may be performed using the same or different catheters. Areas of cardiac tissue may be mapped through the catheter to identify abnormal electrical signals. Ablation may be performed using the same or different catheters. Some catheter ablation procedures, particularly those with persistent atrial fibrillation, may be performed using Electrophysiology (EP) mapping to a target region of abnormal electrical signals. Such EP mapping may include the use of sensing electrodes configured to monitor electrical signals within the cardiovascular system to accurately determine the location of arrhythmogenic abnormal electrically conductive tissue sites. Examples of EP mapping systems are described in U.S. patent No. 5,738,096, which is incorporated herein by reference and appended in the appendix hereof. Examples of EP mapping catheters are described in U.S. patent No. 9,907,480, U.S. patent publication No. 2018/0036078, and U.S. patent publication No. 2018/0056038, each of which is incorporated herein by reference and in the appendix hereof. In addition to using EP mapping, some catheter ablation procedures may also be performed using Image Guided Surgery (IGS) systems. The IGS system may enable a physician to visually track the position of a catheter within a patient in real time relative to an image of an anatomical structure within the patient. Some systems may provide a combination of EP mapping and IGS functionality, including the CARTO 3 ® system of Biosense Webster, inc. Of Irvine, calif. An example of a catheter configured for use with an IGS system is disclosed in U.S. patent No. 9,480,416, which is incorporated herein by reference. Disclosure of Invention A medical probe may include an electrode configured to perform electrical ablation using IRE and/or thermal ablation, while also being configured for sensing functions such as sensing proximity to tissue and/or monitoring electrical signals within the cardiovascular system to identify abnormal conductive tissue sites that lead to arrhythmias. When configured for thermal ablation, the electrodes are of sufficient mass to carry electrical energy and provide thermal conduction and stability for thermal ablation. The electrode may be oriented on an end effector assembly, such as a basket assembly, such that one side of the electrode is positioned to contact tissue and an opposite side is inhibited from contacting tissue. To achieve both efficient delivery of energy and high sensitivity for ECG sensing, an impedance reducing coating may be positioned on the tissue contacting side and an impedance increasing coating may be applied on the opposite side. When configured for IRE, the impedance increasing coating is configured to provide sufficient resistance to provide specificity for tissue proximity indication measurements while being thin enough to allow electrical energy to be delivered through the impedance increasing coating during IRE. An example medical probe includes a shaft,