CN-121987325-A - Electrophysiology catheter system with expandable ablation member for full circumferential ablation of tubular region and related methods

Abstract

A catheter system for use with a catheter having an inflatable balloon member of conical configuration having a maximum radius defined between a distal portion and a proximal portion, the balloon member including a plurality of circumferential flex circuits disposed thereon in the distal portion of the balloon member, the balloon member defining a longitudinal axis, each ablation flex circuit extending circumferentially about the longitudinal axis, wherein the circumferential flex circuits having a compliant radius for contact with tissue are selectively energized at different respective locations along the longitudinal axis to create a full circumferential ablation focus around a tubular region of the heart.

Inventors

• ACHIM ADAM
• S. R. Rampa

Assignees

• 伯恩森斯韦伯斯特(以色列)有限责任公司

Dates

Publication Date

20260508

Application Date

20251030

Priority Date

20241101

Claims (20)

1. 1. A catheter system, comprising: a catheter comprising an ablation balloon member having a membrane and a plurality of ablation flex circuits disposed on the membrane, the ablation balloon member defining a longitudinal axis and each ablation flex circuit extending circumferentially about the longitudinal axis, wherein there are different respective circumferences at different respective locations along the longitudinal axis; a contact sensor disposed on the membrane and configured to provide a contact signal indicative of contact between the balloon member and tissue of the tubular region; A generator configured to provide a current, and A controller configured to selectively transmit the current to a selected flexible circuit in response to the contact signal.
2. 2. The catheter system of claim 1, wherein the contact signal indicates contact of the selected ablation flex circuit with the tissue of the tubular region.
3. 3. The catheter system of claim 1, wherein each ablation flex circuit comprises a substrate and a conductive trace, the substrate configured as an elongated strip having a length and a width, and the conductive trace extending along the length of the strip.
4. 4. The catheter system of claim 3, wherein the conductive trace of each ablation flex circuit is configured to receive the current for ablating tissue.
5. 5. The catheter system of claim 3, wherein a first conductive trace is configured as an active electrode and a second conductive trace is configured as a return electrode, the active electrode and the return electrode being configured to define a circuit within a patient in response to the current, the circuit having a voltage for determining an impedance from which tissue contact of the first conductive trace can be inferred.
6. 6. The catheter system of claim 3, wherein the first conductive trace is configured as an active electrode and the surface-patch electrode is configured as a return electrode, the active electrode and the return electrode being configured to define a circuit within the patient in response to the current, the circuit having a voltage for determining an impedance from which tissue contact of the first conductive trace can be inferred.
7. 7. The catheter of claim 1, wherein the contact sensor comprises an impedance sensor.
8. 8. The catheter of claim 1, wherein the contact sensor comprises a force sensitive resistor.
9. 9. The catheter of claim 1, wherein the balloon member is configured to transition between an expanded configuration and a collapsed configuration.
10. 10. The catheter of claim 9, wherein the balloon member in the inflated configuration has a conical configuration defined by a maximum circumference.
11. 11. The catheter of claim 10, wherein a plurality of flexible circuits are disposed on the balloon member distal to the maximum circumference.
12. 12. The catheter of claim 10, wherein the balloon member has a distal portion distal to the maximum circumference and a proximal portion of the maximum circumference, the distal portion configured with a linear taper and the proximal portion configured with a non-linear taper.
13. 13. The catheter of claim 10, wherein the conical configuration comprises a spherical cone, a long cone, or a necked cone.
14. 14. An ablation catheter, comprising: A control handle; an elongate shaft distal to the control handle, and An ablation end effector, the ablation end effector comprising: A balloon member defining a longitudinal axis between a proximal end and a distal end, the balloon member configured to transition between a collapsed configuration and an expanded configuration; A plurality of flexible circuit strips disposed on the balloon member, each flexible circuit strip extending circumferentially about the longitudinal axis, wherein the flexible circuit strips have different respective radii at different respective locations along the longitudinal axis, each flexible circuit strip including a circumferential electrode configured to contact a circumferential surface of tissue in a tubular region of the heart, and A sensor configured to generate a signal indicative of proximity between tissue and the circumferential electrode.
15. 15. The ablation catheter of claim 14, wherein the balloon member comprises: A frame of flexible strips, each strip configured with a distal end and a proximal end, the distal ends of the strips converging at the distal end of the balloon member, the strips configured to flex radially outward from the longitudinal axis to support the balloon member in the inflated configuration, and A second elongate shaft extending through the elongate shaft, a distal end of the second shaft coupled to the distal end of the balloon member such that longitudinal movement of the second shaft relative to the elongate shaft in a distal direction transitions the balloon member from the expanded configuration to the collapsed configuration.
16. 16. A catheter system, comprising: A catheter, the catheter comprising: An ablation balloon member having a membrane, the balloon member configured with a conical shape having a distal portion and a proximal portion bounded by a maximum radius Rmax, the distal portion configured with a first taper and the proximal portion configured with a second taper; A plurality of ablation flex circuits disposed on the membrane in the distal portion of the balloon member, the ablation balloon member defining a longitudinal axis and each ablation flex circuit extending circumferentially about the longitudinal axis with different respective radii at different respective locations along the longitudinal axis, and A contact sensor disposed on the membrane and configured to provide a signal indicative of contact between the balloon member and tissue of the tubular region; an energy generator configured to provide pulsed field ablation energy, and A controller configured to selectively transmit the pulsed field ablation energy to a selected flex circuit in response to the signal.
17. 17. The catheter system of claim 16, wherein the controller is configured to selectively transmit the pulsed field ablation energy to a selected flex circuit that is an active electrode in a bipolar configuration.
18. 18. The catheter system of claim 16, wherein the controller is configured to selectively transmit the pulsed field ablation energy to a selected flex circuit that is an active electrode in a monopolar configuration.
19. 19. The catheter system of claim 16, wherein the energy generator is further configured to provide an electrical current, the first ablation flex circuit is configured as an active electrode, and the second ablation flex circuit is configured as a return electrode, the active electrode and the return electrode being configured to define an electrical circuit within the patient in response to the electrical current, the electrical circuit having a voltage for determining an impedance from which tissue contact of the first ablation flex circuit can be inferred.
20. 20. The catheter system of claim 16, wherein the energy generator is further configured to provide an electrical current, the first ablation flex circuit is configured as an active electrode, and the body surface patch electrode is configured as a return electrode, the active electrode and the return electrode being configured to define an electrical circuit within the patient in response to the electrical current, the electrical circuit having a voltage for determining an impedance from which tissue contact of the first ablation flex circuit can be inferred.

Description

Electrophysiology catheter system with expandable ablation member for full circumferential ablation of tubular region and related methods Background When a region of cardiac tissue abnormally conducts electrical signals to adjacent tissue, an arrhythmia, such as atrial fibrillation, will occur, disrupting the normal cardiac cycle and causing arrhythmia. The source of the undesired signals may be located in or near the atrium or ventricle. Unwanted signals may be conducted through heart tissue elsewhere where they may trigger or sustain an arrhythmia. Procedures for treating cardiac arrhythmias include surgically disrupting the source of the signal responsible for the arrhythmia, as well as disrupting the conduction pathways for such signals. By mapping the electrical properties of the endocardium and the heart volume and by selectively ablating heart tissue by applying energy, it may be possible to stop or modify the propagation of unwanted electrical signals from one portion of the heart to another. The ablation process may disrupt unwanted electrical pathways by creating areas of non-conductive tissue. In this two-step procedure (including mapping and ablation), electrical activity at various points in the heart may be sensed and measured by advancing a first or mapping catheter containing one or more electrical sensors into the heart and acquiring data at various points. These data may then be used to select a target area to be ablated by the second or ablation catheter. During ablation, RF current is applied to a first electrode of the ablation catheter and current flows through the medium surrounding it (i.e., blood and tissue) to a second electrode, which may be another electrode on the catheter or an external skin patch reference electrode. The distribution of the current depends on the amount of electrode surface in contact with the tissue compared to blood, which has a higher conductivity than the tissue. Due to the electrical resistance of the tissue, heating of the tissue may occur. The tissue is heated sufficiently to cause cell destruction in the target tissue, thereby forming a non-conductive ablation focus. The ablation focus may be formed in tissue contacting the electrode or in adjacent tissue. During this process, heating of the electrode also occurs due to conduction from the heated tissue to the electrode itself. Irreversible electroporation (IRE) using a multi-electrode catheter has been previously proposed in the patent literature. For example, PCT international publication WO 2018/191149 describes electroporation systems and methods for energizing catheters used for delivery electroporation. A catheter for delivering electroporation includes a distal section and an electrode assembly. The distal segment is configured to be positioned in a vein in a body. The vein defines a central axis. The electrode assembly is coupled to the distal segment and includes a structure and a plurality of electrodes distributed about the structure. The structure is configured to at least partially contact the vein. Each electrode is configured to be selectively energized. In one embodiment, each electrode is individually wired such that it can be selectively paired or combined with any other electrode to act as a bipolar or multipolar electrode. As another example, U.S. patent No. 8,295,902 describes a tissue electrode assembly that includes a membrane configured to form an expandable and conformable body that is capable of being deployed within a patient. The assembly also includes a flexible circuit positioned on a surface of the diaphragm. The conductive electrode covers at least a portion of the flexible circuit and a portion of the surface of the septum not covered by the flexible circuit, wherein the conductive electrode is foldable upon itself with the septum into a delivery configuration having a diameter suitable for minimally invasive delivery of the assembly to a patient. In one embodiment, the pattern of multiple electrodes deposited on the separator may collectively form a large electrode array of energy transmitting elements. As yet another example, chinese patent No. CN 112545643 describes a balloon catheter and an ablation system in which an electrode is disposed at a distal end of the catheter and includes an electrode proximal end, an electrode body, and an electrode distal end that are sequentially connected along an extending direction of the catheter, the electrode body is of a mesh structure, at least one of the electrode proximal end and the electrode distal end is movably connected with the catheter, and the electrode body is configured to switch between a contracted state and an expanded state as the electrode proximal end and/or the electrode distal end are moved along the catheter. The balloon catheter comprises a balloon and an electrode, and is used for supporting the electrode body when the balloon is inflated to maintain an inflated state so as to enable the electrode body t