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US-12616519-B2 - Basket assembly with atraumatic tip electrode and methods of making thereof

US12616519B2US 12616519 B2US12616519 B2US 12616519B2US-12616519-B2

Abstract

The disclosed technology includes an expandable basket assembly for a medical probe, which may include a single unitary structure comprising a plurality of spines converging at a central spine intersection, the central spine intersection being positioned on a longitudinal axis of the expandable basket assembly at a distal end thereof. The plurality of spines may include a first layer and a second layer attached to the first layer and including a central cutout about the central spine intersection that exposes the first layer at the central spine intersection. The plurality of spine may include a central electrode attached to the first layer at the central spine intersection via a central aperture in the first layer at the central spine intersection. The second layer may be configured to articulate independently of the first layer at the central spine intersection.

Inventors

  • Kevin Mark Okarski
  • Thanh Nguyen
  • Abubakarr BAH
  • Keshava Datta

Assignees

  • BIOSENSE WEBSTER (ISRAEL) LTD.

Dates

Publication Date
20260505
Application Date
20231107

Claims (20)

  1. 1 . An expandable basket assembly for a medical probe, comprising: a single unitary structure comprising a plurality of spines converging at a central spine intersection, the central spine intersection being positioned on a longitudinal axis of the expandable basket assembly at a distal end thereof; the plurality of spines comprise: a first layer; a second layer attached to the first layer and comprising a central cutout about the central spine intersection that exposes the first layer at the central spine intersection, the second layer comprising a plurality of radial cutouts extending from the central cutout along the second layer of each spine; and a central electrode attached to the first layer at the central spine intersection via a central aperture in the first layer at the central spine intersection.
  2. 2 . The expandable basket assembly of claim 1 , wherein the first layer comprises polyether ether ketone (PEEK), liquid crystal polymer (LCP), or both.
  3. 3 . The expandable basket assembly according to claim 2 , wherein the second layer comprises nitinol, cobalt chromium, or both.
  4. 4 . The expandable basket assembly according to claim 1 , wherein the plurality of spines comprises four to ten spines of the plurality of spines.
  5. 5 . The expandable basket assembly according to claim 4 , wherein the plurality of spines comprises six spines.
  6. 6 . The expandable basket assembly according to claim 1 , further comprising one or more electrodes coupled to each of the spines, each electrode defining a lumen through the electrode so that a spine extends through the lumen of each of the one or more electrodes.
  7. 7 . The expandable basket assembly according to claim 6 , wherein each electrode comprises a wire relief adjacent the lumen to allow for one or more wires to extend adjacent to the lumen.
  8. 8 . The expandable basket assembly according to claim 6 , wherein the lumen is disposed symmetrically about a longitudinal axis of each of the one or more electrodes.
  9. 9 . The expandable basket assembly according to claim 6 , wherein the one or more electrodes are configured to deliver electrical pulses for irreversible electroporation, the pulses having a peak voltage of at least 900 volts (V).
  10. 10 . The expandable basket assembly according to claim 6 , wherein the central electrode is electrically isolated from the one or more electrodes coupled to each of the spines.
  11. 11 . The expandable basket assembly according to claim 1 , wherein the plurality of spines form an approximately spherical shape.
  12. 12 . The expandable basket assembly according to claim 1 , wherein the plurality of spines form an approximately oblate-spheroid shape.
  13. 13 . The expandable basket assembly according to claim 1 , wherein the central electrode is spaced apart from the second layer.
  14. 14 . The expandable basket assembly according to claim 1 , wherein the central electrode comprises a disc- or button-shape.
  15. 15 . The expandable basket assembly according to claim 1 , wherein the first layer is an inner layer and the second layer is an outer layer.
  16. 16 . The expandable basket assembly according to claim 1 , wherein the first layer is an outer layer and the first layer is an outer layer.
  17. 17 . The expandable basket assembly of claim 1 , the first layer comprising polyether ether ketone (PEEK), liquid crystal polymer (LCP), or both, the second layer comprising nitinol, cobalt chromium, or both, the plurality of spines comprising six spines, the plurality of spines forming an approximately oblate-spheroid shape, further comprising one or more electrodes coupled to each of the spines, each electrode defining a lumen through the electrode so that a spine extends through the lumen of each of the one or more electrodes, the lumen being disposed symmetrically about a longitudinal axis of each of the one or more electrodes, the one or more electrodes being configured to deliver electrical pulses for irreversible electroporation, the pulses having a peak voltage of at least 900 volts (V), the central electrode being electrically isolated from the one or more electrodes coupled to each of the spines, the central electrode being spaced apart from the second layer, and the central electrode comprising a disc- or button-shape.
  18. 18 . An expandable basket assembly for a medical probe, comprising: a single unitary structure comprising a plurality of spines converging at a central spine intersection, the central spine intersection being positioned on a longitudinal axis of the expandable basket assembly at a distal end thereof; and the plurality of spines comprise: an outer layer comprising a central cutout and a plurality of radial cutouts extending from the central cutout along the outer layer of each spine; an inner layer attached to the outer layer, the central cutout exposing the inner layer at the central spine intersection; one or more extrusion layers at least partially covering each spine; a central electrode attached to the inner layer at the central spine intersection via a central aperture in the inner layer at the central spine intersection; and one or more electrodes attached to each spine and disposed over a portion of the one or more extrusion layers.
  19. 19 . A method of constructing a medical probe, the method comprising: cutting a planar sheet of a second material to form a second layer of a plurality of spines having a central spine intersection; cutting a center cutout at the central spine intersection; cutting radial cutouts that extend from the center cutout along the second layer of each spine; overmolding a first material on the second layer for forming a first layer; cutting aperture in the first layer at the central spine intersection; and inserting a central electrode into the aperture.
  20. 20 . The method of according to claim 19 , further comprising: attaching a first extrusion layer to partially cover end portions of each spine; attaching a second extrusion layer to cover each spine and the first extrusion layer covering each spine; inserting one or more ring electrodes around each spine; and fitting ends of the plurality of spines to a tubular shaft sized to traverse vasculature such that the central spine intersection is positioned at a distal end of the medical probe and respective spines are movable from a tubular configuration to a bowed configuration.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims, under 35 U.S.C. § 119(e), priority to and the benefit of U.S. Provisional Patent Application No. 63/387,593, filed Dec. 15, 2022, the entire contents of which are incorporated herein by reference. FIELD The present invention relates generally to medical devices, and in particular catheters with basket assemblies and electrodes, and further relates to, but not exclusively, catheters suitable for use to induce irreversible electroporation (IRE) of cardiac tissues. BACKGROUND Cardiac arrhythmias, such as atrial fibrillation (AF), occur when regions of cardiac tissue abnormally conduct electric signals to adjacent tissue. This disrupts the normal cardiac cycle and causes asynchronous rhythm. Certain procedures exist for treating arrhythmia, including surgically disrupting the origin of the signals causing the arrhythmia and disrupting the conducting pathway for such signals. By selectively ablating cardiac tissue by application of energy via a catheter, it is sometimes possible to cease or modify the propagation of unwanted electrical signals from one portion of the heart to another. Many current ablation approaches in the art tend to utilize radiofrequency (RF) electrical energy to heat tissue. RF ablation can have certain rare drawbacks due to operator's skill, such as heightened risk of thermal cell injury which can lead to tissue charring, burning, steam pop, phrenic nerve palsy, pulmonary vein stenosis, and esophageal fistula. Cryoablation is an alternative approach to RF ablation that generally reduces thermal risks associated with RF ablation but may present tissue damage due to the very low temperature nature of such devices. Maneuvering cryoablation devices and selectively applying cryoablation, however, is generally more challenging compared to RF ablation; therefore cryoablation is not viable in certain anatomical geometries which may be reached by electrical ablation devices. Some ablation approaches use irreversible electroporation (IRE) to ablate cardiac tissue using nonthermal ablation methods. IRE delivers short pulses of high voltage to tissues and generates an unrecoverable permeabilization of cell membranes. Delivery of IRE energy to tissues using multi-electrode catheters was previously proposed in the patent literature. Examples of systems and devices configured for IRE ablation are disclosed in U.S. Patent Pub. No. 2021/0169550A1, 2021/0169567A1, 2021/0169568A1, 2021/0161592A1, 2021/0196372A1, 2021/0177503A1, 2021/0186604A1, 2021/0162210, and 2021/0077180, each of which are incorporated herein by reference and attached in the Appendix included with priority application No. 63/387,593. Regions of cardiac tissue can be mapped by a catheter to identify the abnormal electrical signals. The same or different catheter can be used to perform ablation. Some example catheters include a number of spines with electrodes positioned thereon. The electrodes are generally attached to the spines and secured in place by soldering, welding, or using an adhesive. Furthermore, multiple linear spines are generally assembled together by attaching both ends of the linear spines to a tubular shaft (e.g., a pusher tube) to form a spherical basket. Due to the small size of the spines and the electrodes, however, adhering the electrodes to the spines and then forming a spherical basket from the multiple linear spines can be a difficult task, increasing the manufacturing time and cost and the chances that the electrode fails due to an improper bond or misalignment. What is needed, therefore, are devices and methods of forming an improved basket assembly that can help to reduce the time required for manufacturing the basket assembly and alternative catheter geometries in general. SUMMARY Various embodiments of an expandable basket assembly for a medical probe and related methods are described and illustrated. An expandable basket assembly for a medical probe may include a single unitary structure comprising a plurality of spines converging at a central spine intersection, the central spine intersection being positioned on a longitudinal axis of the expandable basket assembly at a distal end thereof. The plurality of spines may include a first layer and a second layer attached to the first layer and including a central cutout about the central spine intersection that exposes the first layer at the central spine intersection. The plurality of spines may include a central electrode attached to the first layer at the central spine intersection via a central aperture in the first layer at the central spine intersection. The second layer may be configured to articulate independently of the first layer at the central spine intersection. The first layer may include polyether ether ketone (PEEK), liquid crystal polymer (LCP), or both. The plurality of spines may include four to ten spines of the plurality of spines. The plurality of spines may include six spines.