EP-4736798-A1 - ELECTROPHYSIOLOGY CATHETER SYSTEM WITH EXPANDABLE ABLATION MEMBER FOR COMPLETE CIRCUMFERENTIAL ABLATION OF TUBULAR REGIONS AND RELATED METHODS

EP4736798A1EP 4736798 A1EP4736798 A1EP 4736798A1EP-4736798-A1

Abstract

A catheter system is for use with a catheter with an expandable balloon member of a conic configuration with a maximum radius delineating between a distal portion and a proximal portion, the balloon member including a plurality of circumferential flexible circuits disposed thereon in the distal portion of the balloon member, the balloon member defining a longitudinal axis, each ablation flexible circuit extending circumferentially around the longitudinal axis with a different respective radius at a different respective location along the longitudinal axis wherein a circumferential flexible circuit with a conforming radius for contact with tissue is selectively energized to create a complete circumferential lesion around tubular region of the heart.

Inventors

ADAME, Alejandro
RAMPA, Sreekanth Reddy

Assignees

Biosense Webster (Israel) Ltd.

Dates

Publication Date: 20260506
Application Date: 20251031

Claims (15)

A catheter system comprising: a catheter including an ablation balloon member with a membrane, and a plurality of ablation flexible circuits disposed on the membrane, the ablation balloon member defining a longitudinal axis and each ablation flexible circuit extending circumferentially around the longitudinal axis with a different respective circumference at a different respective location along the longitudinal axis; a contact sensor disposed on the membrane and configured to provide contact signals indicating contact between the balloon member and tissue of a tubular region; a generator configured to provide electrical current; and a controller configured to selectively transmit the electrical current to a selected flexible circuit in response to the contact signals.
The catheter system of claim 1, wherein the contact signals indicate contact of the selected ablation flexible circuit with the tissue of the tubular region.
The catheter system of claim 1, wherein each ablation flexible circuit includes a substrate and an electrically-conductive trace, the substrate configured as an elongated strip with a length and a width, and the electrically-conductive trace extends along the length of the strip.
The catheter system of claim 3, wherein the electrically-conductive trace of each ablation flexible circuit is configured to receive the electrical current for ablating tissue.
The catheter system of claim 3, wherein i) a first electrically-conductive trace is configured as an active electrode and a second electrically-conductive trace is configured as a return electrode, the active and return electrodes configured to define a circuit in a patient's body in response to the electrical current, the circuit having voltage which is determinative of an impedance from tissue contact of the first electrically-conductive trace can be inferred, or ii) a first electrically-conductive trace is configured as an active electrode and a surface patch electrode is configured as a return electrode, the active and return electrodes configured to define a circuit in a patient's body in response to the electrical current, the circuit having voltage which is determinative of an impedance from which of tissue contact of the first electrically-conductive trace can be inferred.
The catheter of claim 1, wherein the contact sensor includes an impedance sensor or a force sensitive resistor.
The catheter of claim 1, wherein the balloon member is configured to transition between an expanded configuration and a collapsed configuration.
The catheter of claim 7, wherein the balloon member in the expanded configuration has a conic configuration defined by a maximum circumference.
The catheter of claim 8, wherein i) the plurality of flexible circuits are disposed on the balloon member distal of the maximum circumference, ii) the balloon member has a distal portion distal of 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 nonlinear taper, or ii) the conic configuration includes a globose conic, a long conic or a necked conic.
An ablation catheter, comprising: a control handle; an elongated shaft distal of the control handle; and an ablation end effector including: 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 bands disposed on the balloon member, each flexible circuit band extending circumferentially around the longitudinal axis with a different respective radius at a different respective location along the longitudinal axis, each flexible circuit band 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 signals indicative of a proximity between tissue and a circumferential electrode.
The ablation catheter of claim 10, wherein the balloon member includes: a framework of flexible spines, each spline configured with a distal end and a proximal end, the distal ends of the splines converging at the distal end of the balloon member, the splines configured to bow out radially from the longitudinal axis in supporting the balloon member in the expanded configuration; and a second elongated shaft extending through the elongated shaft, a distal end of the second shaft being coupled to the distal end of the balloon member such that longitudinal movement of the second shaft in a distal direction relative to the elongated shaft transitions the balloon member from the expanded configuration to the collapsed configuration.
A catheter system comprising: a catheter including: an ablation balloon member with a membrane, the balloon member configured with a conical shape with a distal portion and a proximal portion delineated 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 flexible circuits disposed on the membrane in the distal portion of the balloon member, the ablation balloon member defining a longitudinal axis and each ablation flexible circuit extending circumferentially around the longitudinal axis with a different respective radius at a different respective location along the longitudinal axis; and a contact sensor disposed on the membrane and configured to provide signals implicating contact between the balloon member and tissue of a 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 flexible circuit in response to the signals.
The catheter system of claim 12, wherein the controller is configured to selectively transmit the pulsed field ablation energy to a selected flexible circuit as an active electrode in a bipolar configuration or as an active electrode in a unipolar configuration.
The catheter system of claim 12, wherein the energy generator is also configured to provide an electrical current, a first ablation flexible circuit is configured as an active electrode and a second ablation flexible circuit is configured as a return electrode, the active and return electrodes configured to define a circuit in a patient's body in response to the electrical current, the circuit having a voltage which is determinative of an impedance from which tissue contact of the first ablation flexible circuit can be inferred.
The catheter system of claim 12, wherein the energy generator is also configured to provide an electrical current, a first ablation flexible circuit is configured as an active electrode and a body surface patch electrode is configured as a return electrode, the active and return electrodes configured to define a circuit in a patient's body in response to the electrical current, the circuit having a voltage which is determinative of an impedance from which tissue contact of the first ablation flexible circuit can be inferred.

Description

BACKGROUND Cardiac arrhythmia, such as atrial fibrillation, occurs when regions of cardiac tissue abnormally conduct electric signals to adjacent tissue, thereby disrupting the normal cardiac cycle and causing asynchronous rhythm. Sources of undesired signals may be located in or near an atria or a ventricle. Unwanted signals may be conducted elsewhere through heart tissue where they can initiate or continue arrhythmia. Procedures for treating arrhythmia include surgically disrupting the origin of the signals causing the arrhythmia, as well as disrupting the conducting pathway for such signals. By mapping the electrical properties of the endocardium and the heart volume, and selectively ablating cardiac tissue by application of energy, it may be possible to cease or modify the propagation of unwanted electrical signals from one portion of the heart to another. The ablation process may destroy the unwanted electrical pathways by formation of non-conducting regions of tissue. In this two-step procedure, which includes mapping followed by ablation, electrical activity at 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 multiple points. These data may then be utilized to select the target areas at which ablation is to be performed by a second or ablation catheter. During ablation, RF current is applied to a first electrode of the ablation catheter and current flows through the media that surrounds it, i.e., blood and tissue, toward a second electrode which may be another electrode on the catheter or an external skin patch reference electrode. The distribution of current depends on the amount of electrode surface in contact with the tissue as compared to blood, which has a higher conductivity than the tissue. Heating of tissue occurs due to its electrical resistance. The tissue is heated sufficiently to cause cellular destruction in the target tissue resulting in formation of a lesion which is electrically non-conductive. The lesion may be formed in tissue contacting the electrode or in adjacent tissue. During this process, heating of the electrode also occurs as a result of conduction from the heated tissue to the electrode itself. Using a multi-electrode catheter for irreversible electroporation (IRE) has been previously proposed in patent literature. For example, PCT International Publication WO 2018/191149 describes electroporation systems and methods of energizing a catheter for delivering electroporation. A catheter for delivery electroporation includes a distal section and an electrode assembly. The distal section is configured to be positioned in a vein within a body. The vein defines a central axis. The electrode assembly is coupled to the distal section and includes a structure and a plurality of electrodes distributed thereabout. The structure is configured to at least partially contact the vein. Each of the electrodes is configured to be selectively energized. In an 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 a multi-polar 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, conformable body that is deployable in a patient. The assembly further includes a flexible circuit positioned on a surface of the membrane. An electrically-conductive electrode covers at least a portion of the flexible circuit and a portion of the surface of the membrane not covered by the flexible circuit, wherein the electrically-conductive electrode is foldable upon itself with the membrane to a delivery conformation having a diameter suitable for minimally-invasive delivery of the assembly to the patient. In an embodiment, a pattern of multiple electrodes deposited on the membrane can collectively create a large electrode array of energy-transmitting elements. As a further example, Chinese Patent No. CN 112545643 describes a balloon catheter and an ablation system, wherein the electrode is arranged at the far end of the catheter and comprises an electrode near end, an electrode main body and an electrode far end which are sequentially connected along the extension direction of the catheter, the electrode main body is of a net structure, at least one of the electrode near end and the electrode far end is movably connected with the catheter, and the electrode main body is configured to be switched between a contraction state and an expansion state along with the movement of the electrode near end and/or the electrode far end along the catheter. The balloon catheter comprises a balloon and the electrode, and is used for supporting the electrode main body to keep an expanded state when the balloon is expanded so as to enable the electrode main body to be attached to a preset object. The balloon moves to the far e