Pulsed-field ablation apparatus and related methods

Abstract

A pulsed-field ablation effector includes (a) an electrode having an electrode surface for delivering an electric current to anatomical tissue, and a deformable insulator selectively covering the electrode surface, the deformable insulator being configured to deform upon contact with anatomical tissue to expose the electrode surface. Methods and devices for performing electroporation and other forms of ablation concurrent with electroporation are also disclosed.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 504,210, filed May 25, 2023, entitled "Pulsed Field Ablation Apparatus And Related Methods"; U.S. Provisional Patent Application No. 63 / 506,898, filed Jun. 8, 2023, entitled "Pulsed Field Ablation Apparatus And Related Methods"; and U.S. Provisional Patent Application No. 63 / 506,900, filed Jun. 8, 2023, entitled "Pulsed Field Ablation Apparatus And Related Methods", the disclosures of each of which are hereby incorporated by reference in their entireties.

[0002] Technical Field The present disclosure is directed to ablation devices, and more particularly, to ablation systems and devices configured to perform pulsed field ablation, their components, and related methods.

Background Art

[0003] This disclosure considers that ablation systems configured to perform pulsed field ablation ("PFA") may be used in a variety of medical and surgical procedures. Generally, PFA systems may be used to ablate target cells while limiting any potential collateral damage to non-target tissues. Typically, PFA involves applying high-voltage electrical pulses to the target tissue. These pulses generate a high-intensity electric field, thereby compromising the integrity of cell membranes within the target tissue. As a result, cells die within a short period (e.g., days to weeks), and lesions are created in the target tissue.

[0004] This disclosure considers that PFA may be used for ablation of cardiac tissue for the treatment of cardiac arrhythmias. Some known PFA techniques, such as catheter-based devices, may produce suboptimal results in some situations. For example, this disclosure considers that it may be difficult to maintain the desired contact pressure between the catheter-based device and the internal cardiac wall, which may result in the resulting injury being improperly positioned and / or less durable than desired.

[0005] While known PFA systems have been used to perform several cardiac ablation procedures, particularly endocardial ablation (e.g., on the inner surface of the heart), improvements in the construction and operation of PFA systems and PFA devices would be beneficial to users (e.g., physicians and surgeons) and patients. This disclosure includes various improvements that may facilitate the construction, operation, and use of PFA systems and PFA devices, including embodiments applicable to epicardial ablation (e.g., on the outer surface of the heart and / or through tissue surfaces). [Overview of the project] [Means for solving the problem]

[0006] A first aspect of the present invention is to provide a pulsed-field ablation effector comprising (a) an electrode having an electrode surface for delivering an electric current to anatomical tissue, and (b) a deformable insulator selectively covering the electrode surface, wherein the deformable insulator is configured to deform when in contact with anatomical tissue to expose the electrode surface.

[0007] In a more detailed embodiment of the first aspect, the deformable insulator includes a slit at least partially occupied by an electrode. In yet another more detailed embodiment, the slit extends longitudinally along the main dimensions of the deformable insulator, and the electrode extends longitudinally within the slit for most of its length. In yet another more detailed embodiment, the pulse-field ablation effector further includes a rigid backer to which the electrode and deformable insulator are mounted. In yet another more detailed embodiment, the deformable insulator is mounted to the rigid backer using a living hinge. In yet another more detailed embodiment, the deformable insulator is embedded within the rigid backer. In yet another more detailed embodiment, the deformable insulator includes a raised feature configured to concentrate contact forces due to contact with anatomical tissue to accelerate the deformation of the deformable insulator. In yet another more detailed embodiment, the raised feature includes a plurality of raised features, at least two of which are located on the opposite side of the electrode. In yet another more detailed embodiment, the plurality of raised features include longitudinal ribs, which generally extend parallel to the electrode.

[0008] In yet another more detailed embodiment of the first aspect, the deformable insulator comprises an elastomer. In yet another more detailed embodiment, the elastomer comprises silicone. In a further detailed embodiment, the electrode is segmented into a plurality of electrodes, the deformable insulator is segmented into a plurality of insulator sections, each of the plurality of electrodes comprises an electrode surface selectively covered by at least one of the plurality of deformable insulator sections, and only the portion of the plurality of deformable insulator sections that is in contact with anatomical tissue deforms to expose the portion of the plurality of electrodes covered by the contacting plurality of deformable insulator sections. In a further detailed embodiment, the deformable insulator is segmented into a plurality of deformable insulator sections, the electrode surface is selectively covered by at least one of the plurality of deformable insulator sections, and only the portion of the plurality of deformable insulator sections that is in contact with anatomical tissue deforms to expose the aspects of the electrode surface covered by the contacting plurality of deformable insulator sections. In a more detailed embodiment, the pulsed-field ablation effector further includes a cryogenic conduit configured to supply cryogenic fluid to a cryogenic tissue contact. In a more detailed embodiment, the cryogenic tissue contact includes the electrode surface of an electrode. In another more detailed embodiment, the pulsed-field ablation effector further includes a radio frequency electrode adapted to deliver radio frequency energy to anatomical tissue. In yet another more detailed embodiment, the radio frequency electrode is selectively coated with a deformable insulator.

[0009] A second aspect of the present invention provides a method for performing pulsed-field tissue ablation, the method comprising: (a) repositioning a pulsed-field ablation effector in close proximity to a target tissue, wherein the pulsed-field ablation effector includes an electrode having an ablation surface covered by a deformable insulator; (b) repositioning the pulsed-field ablation effector to be in sufficient contact with the target tissue, wherein the sufficient contact with the target tissue causes the deformable insulator to deform, exposing the ablation surface of the electrode that was previously covered by the deformable insulator; (c) supplying current to the electrode while in sufficient contact with the target tissue to induce electroporation of the target tissue; and (d) repositioning the pulsed-field ablation effector to no longer be in sufficient contact with the target tissue, wherein the insufficient contact with the target tissue causes the deformable insulator to deform, covering the ablation surface of the electrode that was previously uncovered.

[0010] In a more detailed embodiment of the second aspect, the target tissue is cardiac tissue, and the contact is epicardial contact. In yet another more detailed embodiment, the target tissue is a nerve, and the contact is contact with at least one of an intact nerve and a disconnected nerve. In a further detailed embodiment, the target tissue is an intercostal nerve, and this method is performed concurrently with thoracotomy. In a further detailed embodiment, the target tissue is cardiac tissue, and the contact is endocardial contact. In a more detailed embodiment, the pulsed-field ablation effector includes a first jaw and a second jaw, and the electrodes include a first electrode portion in the first jaw and a second electrode portion in the second jaw, and repositioning the pulsed-field ablation effector to be in sufficient contact with the target tissue includes bringing the first electrode portion into contact with the epicardial tissue and the second electrode portion into contact with the endocardial tissue, such that sufficient contact with the epicardial and endocardial tissues deforms a deformable insulator to expose the first and second electrode portions that were previously covered by the deformable insulator. In a more detailed embodiment, the method further includes performing cryoablation simultaneously with electroporation to cause destruction of the target tissue or adjacent tissue. In another more detailed embodiment, the method further includes performing radio frequency ablation simultaneously with electroporation to cause destruction of the target tissue or adjacent tissue.

[0011] In yet another, more detailed embodiment of the second aspect, when there is insufficient contact between the target tissue and the deformable insulator, the deformable insulator is between the ablation surface of the electrode and the target tissue, and when sufficient contact occurs between the target tissue and the deformable insulator, the deformable insulator is no longer between the ablation surface of the electrode and the target tissue. In yet another, more detailed embodiment, when sufficient contact occurs between the target tissue and the deformable insulator, the tissue contact surface of the electrode erupts from within the deformable insulator. In a further detailed embodiment, the electrode is segmented into a plurality of electrodes, each of which has a tissue contact surface, and the deformable insulator is segmented into a plurality of deformable insulator portions, each of which is selectively covered by at least one of the plurality of deformable insulator portions, and when sufficient contact occurs between the target tissue and each of the plurality of deformable insulator portions, each of the plurality of deformable insulator portions operates to expose the corresponding tissue contact surface of the plurality of electrodes. In a more detailed embodiment, the deformable insulator is segmented into a plurality of deformable insulator portions, and the ablation surface is selectively covered by at least one of the plurality of deformable insulator portions, and when there is insufficient contact between the target tissue and the deformable insulator, the deformable insulator is between the ablation surface of the electrode and the target tissue, and when sufficient contact occurs between the target tissue and each of the plurality of deformable insulator portions, each of the plurality of deformable insulator portions operates to expose a portion of the ablation surface.

[0012] A third aspect of the present invention provides a method for suppressing unintended arcing of a pulsed-field ablation electrode, the method comprising covering the pulsed-field ablation electrode with a deformable insulator, the deformable insulator configured to change its shape between a first shape and a second shape in response to a sufficient external force applied thereto, the first shape covering the tissue contact surface of the pulsed-field ablation electrode and the second shape not covering the tissue contact surface of the pulsed-field ablation electrode.

[0013] The description of exemplary embodiments may be read in conjunction with the accompanying drawings. For the sake of simplicity and clarity of the examples, it should be noted that the components shown in the drawings are not necessarily drawn to scale. For example, the dimensions of some components may be exaggerated relative to others. With respect to the drawings presented herein, embodiments incorporating the teachings of this disclosure are shown and described. [Brief explanation of the drawing]

[0014] [Figure 1] This is a simplified schematic diagram showing an example 100 of a PFA system according to at least some aspects of the present disclosure. [Figure 2] This is a perspective view showing an example 200 of a clamp-type PFA device according to at least some aspects of the present disclosure. [Figure 3A] This is a perspective view showing an example 300 of a minimally invasive PFA device according to at least some aspects of the present disclosure. [Figure 3B] Figure 3A is a simplified schematic diagram showing the PFA device 300. [Figure 4A] This is a perspective view showing an example 400 of a needle-type PFA device according to at least some aspects of the present disclosure. [Figure 4B] Figure 4A is a perspective view showing an example of a needle-type PFA device 400. [Figure 4C] Figure 4A is an enlarged perspective view showing the distal end of needle-type PFA device example 400. [Figure 5A] This figure shows an elongated, generally linear electrode according to at least some aspects of the present disclosure. [Figure 5B] This figure shows a point electrode according to at least some aspects of the present disclosure. [Figure 5C] This figure shows a segment electrode according to at least some aspects of the present disclosure. [Figure 5D] This figure shows examples of nested electrode arrangements according to at least some aspects of the present disclosure. [Figure 5E] This figure shows examples of squiggle electrodes according to at least some aspects of the present disclosure. [Figure 5F] A diagram showing an example of a vertical electrode arrangement according to at least some aspects of the present disclosure. [Figure 5G] A diagram showing an example of a parallel electrode arrangement according to at least some aspects of the present disclosure. [Figure 5H] A diagram showing an example of a continuous electrode according to at least some aspects of the present disclosure. [Figure 5I] A diagram showing an example of two electrode arrays according to at least some aspects of the present disclosure. [Figure 5J] A diagram showing an example of a plate electrode according to at least some aspects of the present disclosure. [Figure 5K] A diagram showing an example of an electrode configuration including a plurality of pairs of cooperating electrodes according to at least some aspects of the present disclosure. [Figure 5L] A diagram showing an example of a raised electrode according to at least some aspects of the present disclosure. [Figure 5M] A diagram showing an example of an electrode configuration including a raised electrode positioned opposite a plate electrode according to at least some aspects of the present disclosure. [Figure 5N] A simplified cross-sectional view showing an example of an alternative electrode configuration that can be used in connection with, for example, PFA devices generally similar to those shown in FIGS. 2, 3A, 4A, and 22 according to at least some aspects of the present disclosure. [Figure 5O] A simplified cross-sectional view showing an example of an alternative electrode configuration that can be used in connection with, for example, PFA devices generally similar to those shown in FIGS. 2, FIG. 3A, FIG. 4A, and FIG. 22 according to at least some aspects of the present disclosure. [Figure 5P] A simplified cross-sectional view showing an example of an alternative electrode configuration that can be used in connection with, for example, PFA devices generally similar to those shown in FIGS. 2, FIG. 3A, FIG. 4A, and FIG. 22 according to at least some aspects of the present disclosure. [Figure 5Q]This is a simplified cross-sectional view showing an example of an alternative electrode configuration that may be used in relation to PFA devices generally similar to the PFA devices shown in, for example, Figures 2, 3A, 4A, and 22, according to at least some aspects of the present disclosure. [Figure 5R] This is a simplified cross-sectional view showing an example of an alternative electrode configuration that may be used in relation to PFA devices generally similar to the PFA devices shown in, for example, Figures 2, 3A, 4A, and 22, according to at least some aspects of the present disclosure. [Figure 5S] This is a simplified cross-sectional view showing an example of an alternative electrode configuration that may be used in relation to PFA devices generally similar to the PFA devices shown in, for example, Figures 2, 3A, 4A, and 22, according to at least some aspects of the present disclosure. [Figure 5T] This is a simplified cross-sectional view showing an example of an alternative electrode configuration that may be used in relation to PFA devices generally similar to the PFA devices shown in, for example, Figures 2, 3A, 4A, and 22, according to at least some aspects of the present disclosure. [Figure 6A] This is a simplified cross-sectional view showing a vacuum clamp configuration according to at least some aspects of the present disclosure. [Figure 6B] This figure shows an example of a basic embodiment including a substantially flat opposing tissue engagement surface according to at least some aspects of the present disclosure. [Figure 6C] This figure shows an example of an embodiment including an opposing convex structure engaging surface according to at least some aspects of the present disclosure. [Figure 6D] This figure shows an example of an embodiment including an opposing concave structure engagement surface according to at least some aspects of the present disclosure. [Figure 6E] This figure shows an example of an embodiment according to at least some aspects of the present disclosure, which includes a cooperating concave structure engaging surface and a convex structure engaging surface. [Figure 7] This is a graphic diagram showing the composition of an example of a multiple burst PFA signal according to at least some aspects of the present disclosure. [Figure 8] This figure shows a table listing examples of PFA signal parameters that may be used in connection with various PFA devices according to at least some aspects of this disclosure. [Figure 9] As part of the description of two-pole / unipolar configurations and two-phase / single-phase signals according to at least some aspects of this disclosure, this is a cross-sectional view showing the arrangement of electrodes relative to each other and the arrangement of tissues on opposite sides. [Figure 10A] This figure shows a plot of an ECG trace example according to at least some aspects of the present disclosure. [Figure 10B] This figure shows two examples of embodiments configured to mechanically measure the distance between opposing jaws, according to at least some aspects of the present disclosure. [Figure 10C] This figure shows four examples of embodiments configured to electrically and / or electronically measure the distance between opposing jaws, according to at least some aspects of the present disclosure. [Figure 10D] This figure shows an example of a ratchet clamp mechanism according to at least some aspects of the present disclosure. [Figure 11A] This is a perspective view showing an example of an insulating configuration, according to at least some aspects of the present disclosure, which includes a compressible insulator that at least partially circumscribing one or more electrodes. [Figure 11B] Figure 11A shows a different perspective view illustrating an example of an insulating structure. [Figure 11C] This is a simplified cross-sectional view showing an embodiment of Figure 11A. [Figure 12A] This is a perspective view showing an example of an insulating configuration forming a shortened electrode exposure region according to at least some aspects of the present disclosure. [Figure 12B] This is a simplified cross-sectional view showing an embodiment of Figure 12A. [Figure 12C] This is another simplified cross-sectional view showing an embodiment of Figure 12A. [Figure 13A] This is a perspective view showing an example configuration including an insulated jaw portion according to at least some aspects of the present disclosure. [Figure 13B]This is a cross-sectional view showing an embodiment of Figure 13A. [Figure 13C] This is a simplified perspective view showing an alternative embodiment in which the electrodes are selectively insulated, according to at least some aspects of the present disclosure. [Figure 14A] This is a perspective view showing an example configuration including a jaw portion having selectively insulated electrodes, according to at least some aspects of the present disclosure. [Figure 14B] This is a cross-sectional view showing an embodiment of Figure 14A. [Figure 14C] Another cross-sectional view showing an embodiment of Figure 14A. [Figure 15A] This is a perspective view showing an alternative configuration example, including a jaw portion having selectively insulated electrodes, according to at least some aspects of the present disclosure. [Figure 15B] This is a cross-sectional view showing an embodiment of Figure 15A. [Figure 15C] Another cross-sectional view showing an embodiment of Figure 15A. [Figure 16A] This is a perspective view showing an alternative configuration example, including a jaw portion having selectively insulated electrodes, according to at least some aspects of the present disclosure. [Figure 16B] This is a cross-sectional view showing an embodiment of Figure 16A. [Figure 16C] This is another cross-sectional view showing an embodiment of Figure 16A. [Figure 17A] This is a perspective view showing an alternative configuration example, including a jaw portion having selectively insulated electrodes, according to at least some aspects of the present disclosure. [Figure 17B] This is a cross-sectional view showing an embodiment of Figure 17A. [Figure 17C] Another cross-sectional view showing an embodiment of Figure 17A. [Figure 18A] This is a perspective view showing an alternative configuration example, including a jaw portion having selectively insulated electrodes, according to at least some aspects of the present disclosure. [Figure 18B] This is a cross-sectional view showing an embodiment of Figure 18A. [Figure 18C] Another cross-sectional view showing an embodiment of Figure 18A. [Figure 18D]This figure shows an example of an embodiment according to at least some aspects of the present disclosure, which includes a deformable insulator positioned around an electrode positioned on a rigid backplate. [Figure 18E] This figure shows an example of an embodiment according to at least some aspects of the present disclosure, which includes spaced supports for electrodes within a deformable insulator. [Figure 18F] This figure shows an example embodiment of at least some aspects of the present disclosure, which includes a deformable insulator bulge mechanism configured to contact tissue and expose an electrode. [Figure 18G] This figure shows an example of an alternative embodiment in which a deformable insulator may be segmented, according to at least some aspects of the present disclosure. [Figure 19A] This is a top view showing an example of a damaged area including a PFA zone and a thermal ablation zone according to at least some aspects of the present disclosure. [Figure 19B] Figure 19A is a cross-sectional view showing the damaged area. [Figure 19C] This is a top view showing an example of damage caused using PFA and RF devices according to at least some aspects of the present disclosure, with the PFA zone and thermal ablation zone shown. [Figure 19D] This figure shows an example of a snare clamp according to at least some aspects of the present disclosure. [Figure 19E] This figure shows examples of generally helical screw engagement components for jaws or electrodes, configured to penetrate target tissue, according to at least some aspects of the present disclosure. [Figure 20] This is a simplified side view showing an example of a PFA device including an expandable structure according to at least some aspects of the present disclosure. [Figure 21] For example, this is a simplified block diagram showing an example of an instrument configuration that may be used to use various PFA and / or RF ablation devices and / or algorithms according to at least some aspects of the present disclosure. [Figure 22]This is a perspective view showing an example of a minimally invasive PFA device according to at least some aspects of the present disclosure. [Figure 23] This figure shows a table listing exemplary parameters or settings for operating a PFA device according to at least some aspects of this disclosure. [Modes for carrying out the invention]

[0015] Examples of embodiments of this disclosure are described and illustrated below to encompass devices, methods, and techniques relating to PFA. Of course, it will be apparent to those skilled in the art that the embodiments considered below are examples and may be reconfigured without departing from the scope and spirit of this disclosure. It should also be understood that variations of the embodiments expected by those skilled in the art will simultaneously constitute part of this disclosure. However, for clarity and accuracy, the embodiments considered below may include optional steps, methods, and features that those skilled in the art should recognize are not requirements for being within the scope of this disclosure. Unless expressly stated otherwise, any feature or function described in relation to any embodiment may apply to any other embodiment, and repetition of descriptions of similar features and functions is omitted for brevity.

[0016] This disclosure considers that PFAs may kill cells by using a high-intensity electric field to induce irreversible nanopore formation in cell membranes, known as irreversible electroporation ("IRE"). IRE may be used to create deep, uniform lesions within cardiac tissue, which may be useful for treating arrhythmias. Reversible electroporation may occur when the electrical signal applied to the target tissue is insufficient in intensity to induce IRE. Pores formed by reversible electroporation may not be permanent, and affected cells typically recover after a short period (e.g., hours, days, weeks). This disclosure considers that the minimum electric field intensity (or voltage) required to induce IRE may depend on the electrical signal applied to the target tissue and the characteristics of the target tissue itself. For example, pulse number, frequency, magnitude, duration, and shape may affect the degree of electroporation. In some circumstances, the area of ​​IRE may be at least partially bounded to the area of ​​reversible electroporation.

[0017] For a given situation, an example of a PFA protocol configured to induce IRE may include a series of energy pulses (i.e., 100 volts direct current (VDC)) for a given duration (i.e., 100 microseconds (μs)) at a given frequency (i.e., 0.1 Hz to 10 Hz). For this type of protocol, an electric field is applied to the tissue to produce a cellular transmembrane voltage potential (CVM) which may range from 0.5 kV / cm to 2.5 kV / cm, depending on how the tissue and tissue damage are assessed. In some situations, the effectiveness of electroporation may not be directly related to the amount of energy or charge delivered. For example, in some situations, two 100 μs pulses of 1000 V / cm may be more effective in inducing IRE than a single 200 μs pulse of similar energy and charge. Additional details and alternatives are described elsewhere in this specification.

[0018] The following description of embodiments with reference to Figures 1, 2, 3A, 3B, and 4A-4C provides context for the features and methods of various apparatus examples described in more detail elsewhere in this specification. It should be understood that any of these embodiments may be used in relation to any feature or aspect described elsewhere in this specification.

[0019] Referring to Figure 1, the PFA system example 100 may include a PFA unit 102, which may be operably coupled with a PFA device 104. The PFA unit 102 may also include a PFA generator 106, which may be configured to generate and / or supply electrical pulses for PFA. The PFA device 104 may be configured to apply PFA pulses to the target tissue 10 in relation to causing damage 12 within the target tissue 10. In some embodiments, the PFA unit 102 may be provided as capital (e.g., reusable) equipment, and / or the PFA device 104 may be provided as disposable (e.g., single-use) equipment.

[0020] In some embodiments, the target tissue 10 may be located inside the patient's body 14. The PFA device 104 may be positioned in close proximity to the target tissue 10 via any preferred patient access 16, such as arterial or venous access, percutaneous access, open surgical access, and / or minimally invasive surgical access. For example, in connection with the treatment of cardiac arrhythmias, the target tissue 10 may include the heart wall (e.g., myocardium). In some embodiments, the PFA device 104 may be positioned generally relative to the outer surface (e.g., epicardium) of the heart wall and / or generally relative to the inner surface (e.g., endocardium) of the heart wall.

[0021] In some embodiments, the PFA unit 102 may include and / or be used in conjunction with various other components. For example, in some embodiments, a foot switch 108 may be used to activate certain functions associated with the PFA unit 102, such as delivering ablation energy to the PFA device 104. In some embodiments, a return electrode 110 may be electrically coupled to the patient's body 14 to provide a return path, for example, for unipolar ablation energy delivered via the PFA device 104.

[0022] In some embodiments, an electrocardiogram ("ECG") monitor 112 may be used to display and / or analyze electrical impulses related to the patient's heartbeat using one or more ECG electrodes 114. In some embodiments, as described below, the ECG monitor 112 may be operably coupled to and / or incorporated into the PFA unit 102, for example, to facilitate synchronization of the timing of ablation pulses with the patient's heartbeat.

[0023] In some embodiments, the PFA unit 102 may be configured to provide only PFA energy. In some embodiments, the PFA unit 102 may be configured for use in connection with additional ablation modalities. For example, the PFA unit 102 may include and / or be used in connection with one or more components configured for RF ablation, such as an RF generator 116, which may be similar to the “Ablation Sensing Unit (ASU),” “Ablation Switch Box (ASB),” and / or “Estech Electrosurgical unit (ESU)” commonly available from AtriCure, Inc. in Mason, Ohio. As another example, the PFA unit 102 may include and / or be used in connection with one or more components configured for cryosurgical ablation, such as a cryosurgical unit 118, which may be similar to the “cryoICE BOX” cryosurgical unit commonly available from AtriCure, Inc. in Mason, Ohio. Generally, a particular area of ​​damage (or a portion thereof) may be formed using PFA, one or more other ablation modalities, or any combination thereof, sequentially and / or simultaneously in any order (e.g., PFA and / or RF and / or cryotherapy).

[0024] In some embodiments, the PFA unit 102 may include one or more indicators and / or displays 120 that may provide the operator with information about the patient, the PFA unit 102, and / or the ablation. For example, some PFA units 102 may include integrated interrogation / mapping functions (e.g., voltage mapping, impedance mapping, cardiac pacing, and exit / inlet block testing of the injured area by detection) and may use one or more dedicated electrodes and / or one or more electrodes associated with the PFA device 104. In some embodiments, the PFA unit 102 may include one or more input devices 122, such as knobs, dials, switches, buttons, or touchscreens, which may allow the operator to control the operation of various components of the PFA unit 102.

[0025] In some embodiments, the PFA unit 102 may be configured with one or more external connections. For example, the PFA unit 102 may be operably coupled to a power source 124, such as a wall outlet. In some embodiments, it may be operably coupled to a vacuum source 126, such as a vacuum system in an operating room. In some embodiments, it may be operably coupled to a gas source 128, such as a compressed gas cylinder, which may contain, for example, a cryogenic fluid.

[0026] In some embodiments, the PFA device 104 may include one or more electrodes 130, which may be located inside or on the end effector 132 to deliver PFA energy to the target tissue 10.

[0027] The descriptions herein refer to distal directions 18 and proximal directions 20. Proximal direction 20 may generally be opposite to distal direction 18. As used herein, “distal” may generally refer to a direction away from the operator of the system or device (e.g., a surgeon), for example, towards the furthest end of the device inserted into the patient’s body. As used herein, “proximal” may generally refer to a direction toward the operator of the system or device (e.g., a surgeon), for example, away from the furthest end of the device inserted into the patient’s body. However, it should be understood that the examples of directions referred herein are for illustrative and clarity purposes only and should not be considered limitations.

[0028] Referring to Figures 1 and 2, the clamp-type PFA device 200 shown may include a proximal handle 202, a shaft 204 extending distally from the handle 202, and / or an end effector 206 positioned distal to the shaft 204. Generally, some PFA device examples 200 may be similar to the “Isolator Synergy” surgical ablation device available from Atlicure, Inc. of Mason, Ohio, and / or the device described in U.S. Patent No. 9,072,518 issued July 7, 2015, entitled “High-Voltage Pulse Ablation Systems and Methods,” which is incorporated herein by reference in its entirety. Furthermore, various PFA devices according to at least some aspects of the present disclosure in any configuration may use overlapping fields (e.g., concentrated between paired electrodes), on / off duty cycles (e.g., for thermal management), and / or constant signal generation that switches between multiple electrode pairs, similar to those used by “Isolator Synergy” devices and / or described in U.S. 9,072,518.

[0029] In general, any handle described herein with reference to any exemplary embodiment may be configured to be grasped by a human user (e.g., a surgeon) and / or to engage with a non-human mechanical device and / or robotic device (e.g., a surgical robot). More generally, any handle described herein may include any structure that can be fixed, held, and / or manipulated to position and / or restrain a PFA device, regardless of whether the PFA device can be held by a human (e.g., a surgeon or assistant), a robot, a mechanical device, etc.

[0030] In the shown embodiments, a proximal connecting component 208 may electrically couple the PFA device 200 with the PFA unit 102. In some embodiments using vacuum and / or cryogenic conditions, the connecting component 208 may include a suitable conduit. The end effector 206 corresponding to the end effector 132 may include a distal repositionable or fixed jaw 210 and / or a movable proximal jaw 212. A plunger 214 or other actuator, which may be positioned proximal to the handle 202, may allow an operator to reposition one or both jaws 210, 212 to clamp the target tissue 10 between them. In the shown embodiments, one or both jaws 210, 212 may include one or more electrodes 216 corresponding to the electrode 130, which may be used to deliver PFA energy to the target tissue 10. In embodiments including one or more electrodes, the electrode(s) may be positioned on either or both jaws 210, 212.

[0031] Referring to Figures 1, 3A, and 3B, the minimally invasive PFA device 300 shown may include a proximal handle 302, a flexible connecting component 304 extending distally from the handle 302, and / or an end effector 306 positioned distal to the connecting component 304. Generally, some PFA device examples 300 may be similar to the "COBRA Fusion" ablation system available from Atricure, Inc. of Mason, Ohio, and / or the device described in U.S. Patent No. 9,474,574 issued on October 25, 2016, entitled "STABILIZED ABLATION SYSTEMS AND METHODS," which is incorporated herein by reference in its entirety.

[0032] In the shown embodiments, a proximal electrical connection component 308 may electrically couple the PFA device 300 with the PFA unit 102. A proximal vacuum connection component 310 may fluidly couple the PFA device 300 with the PFA unit 102 and / or the vacuum source 126. In the shown embodiments, the end effector 306 corresponding to the end effector 132 may include an elongated, flexible stabilizer 312 configured to engage with the target tissue 10 in a releasable manner, for example, by using a vacuum. In the shown embodiments, one or more electrodes 314A, 314B corresponding to the electrode 130 may be located within the stabilizer 312 and / or used to deliver PFA energy to the target tissue 10. In some embodiments, the PFA device 300 may be configured for vacuum-stabilized operation, unidirectional operation, and / or bipolar (or selectively bipolar / unipolar) operation. In some embodiments, the target tissue may be bent, as commonly shown in Figure 3B. In some embodiments, the target tissue may come into contact with electrodes 314A and 314B without substantial tissue bending. The PFA device 2200 shown in Figure 22 may be used in a similar manner.

[0033] Referring to Figures 1 and 4A-4C, the needle-type PFA device 400 shown may include an elongated, flexible connecting component 402 and / or an end effector 404 positioned distal to the connecting component 402. The connecting component 402 may electrically couple the PFA device 400 with the PFA unit 102. In the shown embodiment, the end effector 404 corresponding to the end effector 132 may include a rigid housing 406 and / or one or more electrodes in the form of outwardly extending needles or pins 408, 410 configured to engage with the target tissue 10, for example, by creating a recess in the target tissue 10 or penetrating the target tissue 10. In some embodiments, such penetration may provide desired tissue contact. The electrodes 408, 410 corresponding to electrode 130 may be used to deliver PFA energy to the target tissue 10. In the shown embodiment, the electrodes are spaced at a fixed inter-electrode spacing 412. In some embodiments, at least a portion of at least one pin 408, 410, such as the proximal portion of one or more pins 408, 410, may be covered by an insulator 414, 416. In various embodiments, one or more pins 408, 410 may have generally rounded tips and / or generally sharp tips. Examples of pin contours may include short (shallow depth) pins and / or elongated (deep depth) pins, as well as combinations thereof. In some embodiments, one or more pins 408, 410 may be in the form of hollow needles configured to inject material into target tissue. In some such embodiments, material may be injected into the target tissue, and then PFA energy may be delivered to the target tissue via the needles acting as electrodes.

[0034] In light of the examples of embodiments provided in Figures 1, 2, 3A, 3B, and 4A-4C, a description of various optional and alternative embodiments and features follows below.

[0035] Generally, PFA devices may be configured for unidirectional and / or bidirectional operation. As used herein, “unidirectional” may generally refer to the application of PFA energy to tissue from one side of the tissue. For example, an example of unidirectional operation is applying PFA energy only to the epicardial surface of the heart and not to the endocardial surface on the opposite side. As used herein, “bidirectional” may refer to the application of PFA energy to tissue from two opposite sides so that the PFA energy flows through the tissue.

[0036] Examples of unidirectional devices may include needle-type PFA devices, pen-type PFA devices configured to produce spot and / or linear injury areas, endocardial catheter PFA devices, some minimally invasive epicardial PFA devices, and / or surface-based end effectors including multiple electrodes operating at predetermined different voltages. Some clamp-type devices, such as those using electrodes in only one jaw area, may also have a unidirectional configuration.

[0037] Examples of bidirectional devices may include clamp-type PFA devices, grabbers, several minimally invasive epicardial PFA devices, and / or systems configured to position cooperative electrodes on opposite sides of tissue, such as (e.g., using magnetic coupling) the endocardial and epicardial surfaces of the heart, or the anterior and posterior surfaces of a body conduit. Clamp-type PFA device examples may be configured as pinch clamps or non-pinch clamps, and / or configured to substantially surround an anatomical structure (e.g., a pulmonary vein), or to ablate the wall of a hollow organ via insertion of one jaw portion into a surgical purse-string suture.

[0038] Some PFA devices, such as those described above with reference to Figures 1, 2, 3A, 3B, and 4A-4C, may include various electrode configurations. In general, any combination or variation of the electrode configurations described herein may be used in connection with any embodiment according to at least some aspects of this disclosure.

[0039] Referring to Figures 5A–5T, Figure 5A shows an elongated, generally linear (e.g., "wire") electrode, which may generally be straight, or may include one or more curves and / or angles, and may be repeated as desired to provide multiple electrodes. Figure 5B shows a point (e.g., "spot") electrode, which may generally be circular, or may have other shapes, such as a sheath electrode exposing a point. Figure 5C shows a segment electrode comprising multiple careful, generally rectangular segments, but segments of other similar or different shapes may be used. In some embodiments, the segments may be electrically coupled to one another. These careful parts may be arranged as lines, curves, meandering paths, stacks, or other arrangements. Figure 5D shows an example of a nested electrode arrangement, where one or more electrodes are positioned sequentially inside another. In the embodiments shown, one or more generally annular and / or circular electrodes or electrode segments may generally be arranged concentrically within one another. Nevertheless, other closed shapes may be used, without limitation, such as triangles, rectangles, pentagons, hexagons, octagons, etc.

[0040] Figure 5E shows an example of a wavy electrode including one or a series of elongated electrodes having multiple opposite curves that may resemble a sine curve. Figure 5F shows an example of a vertical electrode arrangement, including one in which the first segment is generally positioned perpendicular to the second segment. These segments may be connected to form a single electrode, or they may be unconnected to form two separate electrodes or segment electrodes. In the embodiments shown, each segment generally includes a straight electrode. Figure 5G shows an example of a parallel electrode arrangement, including one in which the first segment is generally positioned parallel to the second segment. In the embodiments shown, each segment generally includes a straight electrode. In addition, more than two parallel electrodes may be used depending on the application.

[0041] Figure 5H shows an example of a continuous electrode, while Figure 5I shows an example of a two-electrode array. Generally, a continuous electrode may have a continuous surface presented to the tissue regardless of the electrode shape. Generally, a discontinuous electrode array may include two or more segments having separate tissue contact surfaces. Each segment may have any shape, for example, generally circular and / or generally straight. In some embodiments, two or more segments of the electrode array may be electrically connected. In some embodiments, two or more segments of the electrode array may be electrically isolated from each other, for example, each delivering a different electrical signal or the same electrical signal to the tissue.

[0042] Figure 5J shows an example of a plate electrode, which may include a two-dimensional or three-dimensional electrode surface having a substantial width in relation to its length, regardless of its own shape. For example, plate electrodes may be provided in a continuous or segmented configuration. Figure 5K shows an example of an electrode configuration including multiple pairs of cooperating electrodes. Figure 5L shows an example of a raised electrode. Generally, raised electrodes may protrude from the surrounding surface of the PFA device. In some embodiments, one or more electrodes may be coplanar with the surrounding surface; that is, the tissue contact surface of the electrode may be substantially coplanar with the surrounding surface. In some embodiments, one or more electrodes may be recessed into the surrounding surface; that is, the tissue contact surface of the electrode may be inset into the surrounding surface. Figure 5M shows an example of an electrode configuration including a raised electrode positioned opposite a plate electrode.

[0043] Figures 5N to 5T are simplified cross-sectional views of alternative electrode configurations that may be used in relation to PFA devices generally similar to, for example, PFA devices 200, 300, 400, and 2200 according to at least some aspects of the present disclosure. However, it will be understood that similar configurations may be used in other PFA devices. Specifically, Figure 5N shows a longitudinal cross-sectional view of an elongated (e.g., wire) electrode configuration including two electrodes 502 and 504. In this embodiment, the elongated electrodes 502 and 504 may be arranged as a opposing pair for, for example, two-pole operation. The electrodes 502 and 504 may generally be oriented longitudinally and / or at least partially embedded within the ballast 312. Figure 5O shows longitudinal cross-sectional views of several elongated (e.g., wire) electrode configurations including four electrodes 506, 508, 510, and 512. In this embodiment, the elongated electrodes 506, 508, 510, and 512 may be arranged as two opposing pairs and / or generally oriented longitudinally. However, more than two pairs of electrodes are within the scope of this disclosure. Figure 5P shows side cross-sectional views of a continuous electrode configuration 514 and a segmented electrode configuration 516. In the shown embodiment, the individual electrodes 516A, 516B, and 516C of the segmented electrode configuration 516 may be electrically connected as a group, driven individually, or individually in contact with target tissue.

[0044] Figure 5Q shows a side view of an example electrode arrangement including opposing tissue-penetrating needle electrodes. In the shown embodiment, a first jaw portion 517 includes at least one needle electrode 518 extending therefrom. A second opposing jaw portion 519 includes at least one needle electrode 520 extending therefrom. In the shown embodiment, the needle electrodes 518, 520 are arranged as respective arrays. The spacing between the needles 518, 520 may be fixed to a known defined distance. The shown embodiment includes jaw portions 517, 519 which may represent jaw portions 210, 212 of a clamp-type PFA device (e.g., PFA device 200 shown in Figure 2), but it will be understood that such opposing needle arrangements may be used by PFA devices of other configurations, such as PFA devices 300, 400, etc.

[0045] Figure 5R shows a partially cutaway perspective view of the minimally invasive PFA device 2200 shown in Figure 22, where the electrodes may generally be in the form of helical electrodes 2202. Figure 5S shows a simplified distal perspective view of an example electrode configuration including multiple archwire electrodes 522. In this embodiment, the archwire electrodes 522 may be at least partially arranged within a stabilizer (Figure 3A), and may generally be parallel, laterally oriented, and / or configured to engage with target tissue at their respective concave surfaces. In addition, Figure 5T shows a simplified distal perspective view of an example electrode configuration including multiple archplate electrodes 524. In this embodiment, the archplate electrodes 524 may be at least partially arranged within a stabilizer (Figure 3A), and may generally be parallel, laterally oriented, and / or configured to engage with target tissue at their respective concave surfaces. Generally, the archplate electrodes 524 in Figure 5T may be similar to the archwire electrodes 522 in Figure 5S. However, in some embodiments, the archplate electrode 524 may be wider than the archwire electrode 522 (e.g., in the longitudinal direction).

[0046] In some embodiments, the clamp-type PFA device (e.g., similar to PFA device 200) may include a variety of features. Generally, the clamp-type device may be configured for dynamic closure and / or static closure.

[0047] Embodiments configured for dynamic closure may utilize static and / or dynamic jaws. For example, a static jaw (e.g., a jaw that does not change orientation during use) may be dynamically configured by the use of a spring closure mechanism. In some such embodiments, the closing force is substantially provided by a spring force, and the separation of the jaw in the closure configuration depends on the thickness and compressibility of the tissue. In other embodiments, a static jaw may be dynamically configured by using a closing force applied by the user. Thus, the separation and closing force of the jaw in the closure configuration are directly controlled by the user. Embodiments including a dynamic jaw may include a compressible jaw surface, a conforming jaw (e.g., a jaw that deforms when subjected to a design closing force), and / or a flexible jaw.

[0048] Some embodiments configured for static closure may use pressure settings; that is, a closing force up to a preset desired level may be applied. In such a situation, any further applied closing force would not be effective in further closing the jaw.

[0049] Referring to Figure 6A, some embodiments configured for static closure may use a fixed distance setting. That is, the jaws are closed to a predetermined jaw spacing, regardless of the closing force required to achieve such spacing. In some embodiments using a fixed distance setting, the PFA device may use both a clamp and a vacuum tissue engagement mechanism. For example, Figure 6A shows a simplified cross-sectional view of a vacuum clamp configuration according to at least some aspects of the present disclosure. In the shown embodiment, the jaws are positioned around the target tissue and moved into the closure configuration. Vacuum is applied to the jaws to maintain or increase the desired tissue contact with the jaws.

[0050] Some embodiments may be configured for hybrid set-distance / dynamic closure operation. For example, the initial closure of the clamp may be performed to a set distance. This may facilitate PFA at, for example, a fixed or known V / cm. The clamp may then be dynamically closed, for example, in preparation for RF ablation. Some embodiments may include a closure mechanism that provides such a series of operations or that is switchable (e.g., user selectable) between such operating modes. In some embodiments, the operating mode of the closure mechanism (e.g., dynamic distance vs. fixed distance) may be determined in relation to selecting the output of the electrosurgical generator (e.g., PFA vs. RF ablation). In an alternative embodiment, dynamic closure may be performed first, followed by set-distance closure, for example, to perform PFA following RF ablation.

[0051] Some embodiments may use a variable distance setting. That is, the jaw may be closed to a certain distance, which may be determined by the user and / or indicated by a stopper or visible scale, but which may vary from ablation to ablation.

[0052] Referring to Figures 6B-6E, some embodiments may use opposing jaws that include a cooperative tissue engagement mechanism. For example, the insulating portion of the jaw adjacent to the electrode may be configured with various shapes for engaging with the target tissue. Figure 6B shows a basic embodiment including a substantially flat opposing tissue engagement surface, Figure 6C shows an embodiment including an opposing convex tissue engagement surface, Figure 6D shows an embodiment including an opposing concave tissue engagement surface, and Figure 6E shows an embodiment including a cooperative concave tissue engagement surface and an opposing convex tissue engagement surface, all of which are at least some aspects of the present disclosure.

[0053] In some embodiments, the tissue-engaging surface (e.g., an insulator) may be substantially rigid; that is, the insulator does not substantially deform under the design load. In some embodiments, the tissue-engaging surface (e.g., an insulator) may be substantially conformable; that is, the insulator may be configured to deform when subjected to the design load, for example, to conform to the target tissue. In some embodiments, the tissue-engaging surface may be partially rigid and / or partially conformable so as to be suitable for achieving the desired tissue contact.

[0054] Referring to Figure 7, a graphic diagram of the configuration of an example of a multiple burst PFA signal according to at least some aspects of this disclosure is shown. In addition, Figure 8 shows a table listing example PFA signal parameters that may be used in relation to various PFA devices according to at least some aspects of this disclosure. In Figure 8, “fusion” refers to a device similar to the PFA device 300 shown in Figure 3, “needle” refers to a device similar to the PFA device 400 shown in Figures 4A-4C, “clamp” refers to a device similar to the PFA device 200 shown in Figure 2, “epi endo” refers to a PFA system including an epicardially positioned PFA device that works in cooperation with an endocardially positioned PFA device, and “evenflow” refers to a PFA device including multiple electrodes that operate at predetermined different voltages. The parameters listed are merely examples and should not be considered limiting in any way.

[0055] In various embodiments, the PFA signal may include single-phase pulses and / or two-phase pulses. Individual pulses may include square waves, and / or the voltage may change over time. For example, individual pulses may generally include sinusoidal waveforms. Individual pulses may be delivered in bursts (e.g., pulse trains). A series of multiple bursts may be delivered. In some embodiments, pulses may be delivered at specific predetermined times relative to the patient's heartbeat.

[0056] The characteristics of the pulse may be modified and selected to achieve the desired result. For example, alternating current ("AC") or direct current ("DC") waveform, pulse amplitude, number of pulses in the pulse train, number of bursts, pulse repetition frequency, burst repetition frequency, pulse width (e.g., nanoseconds or more), etc., may be modified. In some embodiments, some or all of the characteristics may remain substantially constant. In some embodiments, one or more characteristics may change, for example, during ablation. For example, some characteristics may be programmed to change over time.

[0057] In some embodiments, the operation of the PFA system may be configured to measure one or more parameters in real time or at a delayed time in relation to the ablation operation, and / or to use data related to such parameters in relation to the control of PFA energy delivery. In some embodiments, several aspects of PFA energy delivery may be enabled and / or suppressed based at least in part on the detection and / or measurement of several parameters. In some embodiments, one or more aspects of PFA energy delivery may be regulated and / or controlled based at least in part on the detection and / or measurement of one or more parameters.

[0058] In some embodiments, the contact force between the end effector and the target tissue, or parameters related to that contact force, may be measured. For example, in embodiments using vacuum stabilization, the vacuum level may be measured. In embodiments using magnetic force, the magnetic force may be measured.

[0059] In some embodiments where the electrode spacing may vary, such spacing may be measured as described elsewhere in this specification.

[0060] In some embodiments, one or more temperatures may be measured. For example, the temperature of one or more end effectors, the temperature of an electrode, and / or the temperature of tissue may be measured.

[0061] In some embodiments, tissue conductivity may be measured. For example, tissue conductivity may be measured using the same electrodes that may be used to deliver PFA energy. Alternatively, additional electrodes different from those used to deliver PFA energy may be used to measure tissue conductivity. The measured tissue conductivity may be evaluated as a value of absolute conductivity and / or in view of the change in conductivity, for example, as a percentage change in conductivity brought about by ablation. In some situations, tissue conductivity may increase with PFA, so such measurements may facilitate the evaluation of the effectiveness and / or progress of ablation.

[0062] In some embodiments, the current delivered in relation to the PFA may be measured.

[0063] In some embodiments, the ablation time may be measured.

[0064] This disclosure considers that tissue selectivity, which can demonstrate the ability to target and destroy specific tissues while minimizing damage to other untargeted neighboring tissues, may be a relevant consideration when ablating tissue. For example, myocardial tissue ablation may occur near the phrenic nerve, esophagus, and coronary arteries.

[0065] This disclosure acknowledges that the tissue selectivity of PFA may be influenced by various factors, including the duration and intensity of the electric field, the shape and size of the electrodes, and the electrical properties of the target tissue. Generally, PFA may be more selective to tissues with higher electrical conductivity, such as cardiomyocytes, and less selective to tissues with lower conductivity, such as adipose tissue or fibrous tissue. In some situations, PFA energy delivered via an electrical signal having particular characteristics may be substantially destructive to cardiomyocytes and / or minimally destructive to nerve tissue and / or blood vessels.

[0066] This disclosure takes into consideration that, as given by the following equation, the electric field strength (E) (also called the applied electric field) is generally proportional to the applied voltage (V) and inversely proportional to the electrode spacing (d).

[0067]

number

[0068] The electrode spacing (d) is defined as the distance between electrodes used to deliver high-voltage electrical pulses to the target tissue. In some embodiments, IRE may be generated by electric field strengths of approximately 2500 V / cm to 10,000 V / cm.

[0069] The disclosure acknowledges that electrode spacing can affect the spatial distribution of the electric field within tissue. Specifically, as electrode spacing increases, the electric field may become less concentrated in order to distribute over a larger area, while at smaller electrode spacings, the electric field may become more concentrated in order to concentrate over a specific region of tissue.

[0070] This disclosure considers that electrode exposure can also affect the spatial distribution of the electric field within the tissue. Electrode exposure refers to the amount of electrode surface area in direct contact with the tissue being treated. Generally, greater electrode exposure may result in a more uniform electric field distribution within the tissue, which may lead to more effective destruction of the target tissue. Conversely, less electrode exposure may result in a more localized electric field distribution within a smaller tissue footprint. Electrode exposure can be controlled by adjusting the size and shape of the electrodes, and / or by changing the distance between the electrodes and the tissue. In some cases, multiple electrodes (more than two) may be used to achieve greater electrode exposure and / or a more uniform electric field distribution.

[0071] This disclosure considers that pulse width may play an important role in determining the effectiveness of PFA treatment. Pulse width may indicate the duration for which the electric field is applied to the tissue. Generally, longer pulse widths may correspond to an increased likelihood of causing IRE. However, in some situations, if the pulse width is too short, insufficient energy may be delivered to the tissue to produce the desired effect.

[0072] This disclosure considers that dwell can determine the amount of energy delivered to tissue during PFA and therefore may affect the degree of tissue damage. Dwell may refer to the time between individual pulses and / or the time between packets or groups of pulses.

[0073] This disclosure considers that the pulse repetition frequency may affect the duration and / or frequency at which tissue is exposed to an electric field, which may affect efficacy, selectivity, and / or safety in some situations. Generally, the pulse repetition frequency indicates the frequency at which electrical pulses are delivered during PFA. In some situations, increasing the pulse repetition frequency may increase selectivity and reduce the likelihood or magnitude of undesirable muscle stimulation.

[0074] This disclosure considers that the number of pulses delivered to the tissue may affect the degree of tissue damage and / or the effectiveness of the procedure. The pulse count may represent the total number of individual times during which a high voltage current is applied to the target tissue. Generally, reducing the pulse count for a given high voltage current may reduce the possibility of undesirable heating of the tissue.

[0075] Referring to Figure 9, the following descriptions of two-pole / unipolar configurations and two-phase / single-phase signals according to at least some aspects of this disclosure are illustrated.

[0076] The terms “bipolar” and “unipolar” may refer to the electrical configuration of electrodes used to deliver high-voltage electrical pulses to the tissue being treated. Generally, in a unipolar configuration, a single active electrode (or electrode group) may be used to deliver electrical pulses to the tissue, while another electrode and / or grounding pad are typically placed elsewhere on the patient's body to complete the circuit. Such configurations may result in a less controlled electric field distribution and / or damage to healthy tissue near the treatment area. In a bipolar configuration, two active electrodes (or electrode groups) may be placed near the tissue being treated, and high-voltage electrical pulses are delivered between these two electrodes. Such configurations may result in a more localized electric field distribution, thereby reducing the risk of damage to healthy tissue outside the treatment area. Both bipolar and unipolar configurations have been used in PFA, but in some situations, bipolar configurations may offer some safety and / or efficacy advantages. For example, in some situations, a bipolar configuration may provide improved electric field control and / or more controlled injury formation, and / or cause less skeletal muscle stimulation.

[0077] The terms "two-phase" and "single-phase" may refer to the waveforms of the electrical pulses used in PFA procedures. A single-phase pulse may consist of a single high-voltage electric field applied to the tissue over a short duration. Such pulses may be thought of as unidirectional waves propagating through the tissue. A two-phase pulse may consist of two pulses of opposite polarity applied in succession. The polarity of the electric field is reversed between the two pulses, resulting in a bidirectional waveform that oscillates back and forth through the tissue. In some situations, two-phase pulses may more effectively disrupt the cell membranes of certain tissues compared to single-phase pulses.

[0078] This disclosure considers that in some circumstances, the delivery of electrical energy to body tissues may result in muscle contraction. In some circumstances, muscle tissue may contract in response to direct stimulation by electrical energy. In some circumstances, muscle tissue may contract in response to stimulation of nerve tissue by electrical energy. In the context of electrical ablation of cardiac tissue, electrical energy may cause stimulation of the myocardium and / or non-cardiac skeletal muscle. For example, such stimulation may include involuntary contractions and / or unilateral contractions.

[0079] In some embodiments, the delivery of PFA energy to cardiac tissue may be timed to coincide with the patient's heartbeat. For example, the delivery of PFA energy may be timed to coincide with a specific part of the cardiac cycle, and / or not to coincide with a specific part of the cardiac cycle. For example, electrical energy may be applied when the heart is in a refractory period, which may reduce the likelihood of muscle spasms. Plots of ECG trace examples according to at least some embodiments of this disclosure are disclosed, for example, as shown in Figure 10. In some embodiments, PFA energy delivery may be initiated on the downslope of the R wave, thereby reducing the likelihood of undesirable abnormal cardiac stimulation and / or arrhythmias. Specifically, on the downslope of the R wave, cells are already depolarized and therefore generally unable to respond to the PFA signal. In some situations, by applying the first of a series of pulses on the downslope of the R wave, subsequent pulses may be applied at different frequencies without adverse effects. In particular, regardless of the frequency of the subsequent pulses, the heart may be stimulated to beat at a maximum velocity of about 5 beats per second, which is expected to return to normal sinus rhythm after ablation.

[0080] In some embodiments that use a pacing signal to drive the heart at a known speed, PFA energy delivery may be timed to coincide with the pacing signal.

[0081] In some embodiments, the PFA energy delivery parameters may be selected to reduce the possibility of undesirable cardiac and / or skeletal muscle stimulation. For example, less muscle stimulation may be achieved by delivering electrical energy at frequencies of approximately 100 kHz or higher.

[0082] This disclosure considers that at certain voltages used for PFA, arcing can occur between electrodes, potentially leading to undesirable tissue burns, cardiac arrest, hearing loss, blindness, nerve damage, and / or death depending on the placement of the PFA electrodes. In other PFA situations, arcing can occur between the electrodes of the PFA device and the patient's tissue (e.g., target or non-target tissue). Therefore, mitigating unintended arcing may be a consideration for the design and operation of the PFA system.

[0083] In some embodiments, arcing may be reduced by ensuring sufficient contact force or pressure between the PFA electrode and the target tissue. For example, some embodiments may use vacuum stabilization to increase the contact pressure. The vacuum pod may include a fluid flow with a conductive fluid to ensure tissue-to-electrode bonding. Some embodiments may use a clamp-type configuration to increase the contact pressure. Some embodiments may use an expandable structure to increase the contact pressure.

[0084] In some embodiments, arcing may be reduced by coating, drenching, and / or immersing the electrodes and / or tissue with a dielectric fluid, such as deionized water.

[0085] In some embodiments involving multiple electrodes, one or more electrodes may be selectively activated and / or deactivated. For example, in connection with a specific application of PFA energy, one or more electrodes in contact with the target tissue may be activated, and / or one or more electrodes not in contact with the target tissue may be deactivated / deactivated. For example, one or more electrodes not in contact with any tissue and / or one or more electrodes in contact with tissue other than the target tissue may be deactivated. The electrodes may be deactivated manually by the user or automated by an electrical contact test with an applied voltage to confirm tissue contact, or any combination thereof. In some embodiments, several electrodes may be selectively used for a particular ablation modality (e.g., PFA, RF).

[0086] In some embodiments of a PFA device including two or more electrodes, the PFA device may be constructed such that the spacing between adjacent electrodes is sufficient to avoid arcing at a desired voltage. For example, the minimum spacing to avoid arcing may be determined when the maximum voltage difference between two adjacent electrodes is given. In some embodiments, when the device is constructed by rigidly arranging electrodes at a desired spacing, such spacing may be fixed. In some embodiments, such as a clamp-type device having electrodes arranged on opposing jaws, mechanical control may be incorporated to limit the closing movement of the jaws to a minimum separation distance that provides sufficient electrode spacing to avoid arcing, and / or electrical control may be incorporated to suppress electrode movement when the electrode spacing is insufficient. Such control may be located on the end effector and act on or near one or more jaws, and / or located on the handle and act on or near the actuation component operated by the user, and / or located on the PFA unit 102 as physical circuitry and / or programming code.

[0087] In some embodiments, potential arcing conditions may be detected and / or prevented. For example, a PFA device and / or PFA unit may be configured to prevent the delivery of PFA energy when potential arcing conditions are detected. Alternatively, a PFA device and / or PFA unit may be configured to adjust its operation based on the detection of potential arcing conditions. For example, electrodes not in contact with tissue may be disabled, allowing the application of PFA energy only through electrodes substantially in contact with tissue. In some embodiments, parameters related to arcing conditions may be detected, and energy delivery may be terminated. For example, when voltage, current, conductivity, impedance, or other electrical parameters related to arc initiation are detected, PFA unit example 102 may terminate energy delivery to the PFA device.

[0088] Some embodiments that enable variable electrode spacing (e.g., at least one electrode can be repositioned relative to at least one other electrode) may be configured to measure the electrode spacing, for example, before PFA energy is delivered to the electrodes. In some clamp-type embodiments, determining the jaw separation distance may correlate with the electrode spacing. For example, if it is determined that the electrode spacing is insufficient to prevent arcing at a desired voltage, the PFA system may prevent the delivery of PFA energy to the electrodes. In some embodiments, the maximum voltage delivered to the electrodes may be adjusted based at least in part on the detected or determined electrode spacing. That is, for example, the maximum voltage may be lower when a closer electrode spacing is detected or determined, and / or higher when a farther electrode spacing is detected or determined.

[0089] In some clamp-type PFA devices, jaw separation may be mechanically and / or electrically controlled and / or determined. Examples of mechanical configurations may include, for example, a mechanism configured to measure the distance between opposing jaws, a ratchet mechanism related to the distance between jaws, a window cut-out on the shaft or handle indicating jaw separation, and / or ruler marks on the shaft. Examples of electrical configurations may include magnets and Hall sensor devices, linear potentiometers, lasers, echoes, infrared light, and / or tissue impedance.

[0090] Referring to Figure 10B, two examples of embodiments configured to mechanically measure the distance between opposing jaws are shown. As shown, in some embodiments, the ruler marks may be provided to a stationary component relative to a moving drive bar, for example, or to the moving drive bar.

[0091] Referring to Figure 10C, four examples of embodiments configured to electrically and / or electronically measure the distance between opposing jaws are shown. As shown, some embodiments may include, for example, a linear potentiometer (or linear encoder), a Hall sensor, a laser / echo / or IR distance meter, and / or a rotary potentiometer (or encoder).

[0092] This disclosure considers that the voltage associated with PFA may be substantially higher than the voltage associated with RF ablation. Therefore, PFA devices may use increased electrical isolation compared to RF-only devices. For example, it may be advantageous to construct the PFA device from non-conductive materials and / or to isolate (or increase the isolation of) conductive components of the PFA device. As an example, it may be advantageous to electrically isolate a tubular metal shaft extending between the handle and the end effector.

[0093] In some embodiments, the materials(s) used to construct the electrodes may be selected to reduce the likelihood of arcing. For example, some electrodes may be constructed entirely from a single material having certain characteristics. In some embodiments, a portion of the electrode (e.g., the body portion) may be constructed from a first material and at least partially coated (e.g., plated or coated) with a second material different from the first material. Examples of electrode materials include, but are not limited to, copper, gold, and nickel.

[0094] In some embodiments, one or more electrodes may be shaped to reduce the likelihood of arcing. For example, in some embodiments, curved edges with a relatively large radius may be less prone to arcing than sharp corners and / or sharp protrusions. In some embodiments, an array of multiple relatively small electrodes may be less prone to arcing than a single relatively large electrode.

[0095] Referring to Figure 10D, various clamp-type PFA devices according to at least some aspects of the present disclosure may utilize a ratchet clamp mechanism. One such example of a ratchet clamp mechanism is shown. In the shown embodiment, the mechanism, specifically the interaction between the notch and the pin / plate, may be configured to allow the plunger, drive bar, and clamp jaws to move in the closing direction while preventing movement in the opening direction. The clamp jaws may be made to move in the opening direction when desired by using a release bar to pull the pin / plate out of the notch.

[0096] In some embodiments, the PFA device may include one or more insulators and / or electrode arrangements configured to reduce the possibility of arcing. Examples of the following features are shown and described separately in the context of the clamp-type PFA device 200, but one or more similar features may be used in relation to any PFA device configuration, including those generally similar to the minimally invasive PFA device 300.

[0097] Referring to Figures 11A and 11B, an example of an insulating configuration is shown which includes a compressible insulator that at least partially surrounds one or more electrodes. Figure 11C is a simplified cross-sectional view of the embodiments of Figures 11A and 11B. In the embodiments shown, the jaw portion 1102 may include one or more electrodes 1104 configured to deliver PFA energy positioned on a tissue engagement surface. One or more compressible insulators 1106 may at least partially surround the electrodes 1104. In the embodiments shown, the compressible insulators 1106 may be formed from a flexible, compressible insulating tube fixed to the outer periphery of the jaw portion 1102. When an object (e.g., tissue) is clamped between the jaw portions 1102, the compressible insulators 1106 deform (see Figure 11C) so that the electrodes 1104 effectively protrude from the jaw base and make direct contact with the clamped object. In contrast, when no object is clamped between the jaws 1102, the compressible insulator 1106 protrudes from the jaw base and extends outward beyond the reach of the electrode 1104, thereby reducing accidental discharge to unintended objects. The insulator 1106 may be set to a height that ensures the electrode 1104 never makes direct contact, or to a height that ensures minimal electrode separation is maintained. The durometer of 1106 may be selected to achieve a specific compressibility, and it may be relatively harder or softer than the tissue clamped between the opposing jaws.

[0098] Referring to Figure 12A, an example of an insulating configuration forming a shortened electrode exposure region is shown. Figures 12B and 12C are simplified cross-sectional views of the embodiment shown in Figure 12A. In the shown embodiment, the jaw portion 1202 may include one or more electrodes 1204 configured to deliver PFA energy positioned on the tissue contact surface. One or more portions of the electrodes 1204 may have their tissue contact length reduced by being at least partially covered by a fixed or adjustable (sliding) insulator. In the shown embodiment, a first insulator 1206 may cover a portion of the jaw portion 1202 adjacent to the heel, and / or a second insulator 1208 may cover a portion of the jaw portion 1202 adjacent to the toe. Thus, the central portion 1210 of the jaw portion 1202 may generally be left uncovered to allow contact between the electrode and the target tissue. In the embodiment shown, the first and second insulators 1206 and 1208 may be formed from silicone tape wrapped around the jaw portion 1202. In addition, an insulator other than silicone may be used to prevent direct contact between a portion of the electrode 1204 and the tissue.

[0099] Referring to Figure 13A, an example configuration including an insulated jaw is shown. Figure 13B is a cross-sectional view of the embodiment shown in Figure 13A. In the shown embodiment, the jaw 1302 may be constructed from one or more nonconductive (e.g., insulating) materials. The electrodes 1304 may be embedded in and / or positioned on the jaw 1302. Thus, in contrast to embodiments including one or more conductive materials in which the jaw is exposed to the outside, the risk of arcing between the electrodes and the jaw may be reduced.

[0100] Some embodiments of at least some aspects of this disclosure may include one or selectively exposed electrodes. For example, some embodiments may include one or more electrodes that can be at least partially covered by one or more relatively flexible, deformable insulators. In some embodiments, the one or more insulators may be configured to allow contact between the electrodes and target tissue by elastically deforming and / or moving, thereby at least partially exposing one or more electrodes. Generally, in some embodiments, the electrodes may remain at least partially covered by the insulators when not in contact with target tissue. In some embodiments, the insulators may be constructed from a flexible, compressible material. The material properties may be selected so that the material moves when clamped over tissue (e.g., at least partially exposing the electrodes). In some alternative embodiments, the insulators may be constructed from a material having self-healing properties.

[0101] Some embodiments may be constructed with one or more slits configured to facilitate elastic movement and / or electrode exposure. In various embodiments, the electrodes may have any shape, including a shape configured to facilitate exposure. For example, some electrodes may be generally circular, generally rectangular, generally teardrop-shaped, generally parabolic, and so on.

[0102] In some embodiments, the insulator may be overmolded onto the electrode. For example, the insulator may be overmolded and / or bonded to a generally smooth wire electrode. In some embodiments, the electrode may include a coupling mechanism, such as a transverse through-hole, configured to facilitate coupling and retention between the insulator and the electrode. In some embodiments, the electrode may be inserted into an opening in the insulator.

[0103] Some embodiments may include a relatively rigid backing support provided in or near a relatively flexible insulator. For example, the backing may be in the form of a flat plate and / or a grooved block, which may reduce the rotation and / or twisting of the electrode. Some embodiments may include an intermittent support configured to support the electrode against a relatively rigid structure (e.g., a jaw) beneath it.

[0104] Referring to Figure 13C, an alternative embodiment is shown in which the electrode 1306 is selectively insulated. In some embodiments, the configuration in Figure 13C may be used instead of the exposed electrode configuration in Figure 13B. In the embodiments shown, an insulator 1308, which may be constructed of an insulating, deformable material, may be positioned to at least partially cover the electrode 1306. In a manner generally similar to those described below with reference to other selectively insulated electrodes, the insulator 1308 may be deformable to at least partially expose the electrode 1306, for example, when engaging with a target tissue. In the embodiments shown, the insulator 1308 may generally include a longitudinal slit mechanism 1310, which may facilitate the selective exposure of the electrode 1306.

[0105] Referring to Figure 14A, an example configuration is shown that includes a jaw portion having selectively insulated electrodes. Figures 14B and 14C are cross-sectional views of the embodiment of Figure 14A when the electrodes are in contact with target tissue. In the shown embodiments, the jaw portion 1402 may include one or more electrodes 1404, 1406 on the tissue engagement surface. Referring to Figure 14B, when the jaw portion 1402 is not in contact with tissue, one or more deformable insulators 1408, 1410 may at least partially cover one or more electrodes 1404, 1406. In some embodiments, the insulators 1408, 1410 may be constructed from, for example, flexible silicone or other suitable materials. In the shown embodiments, each insulator 1408, 1410 substantially covers the entire length of each electrode 1404, 1406, and a central slit runs between the inner surfaces of the insulators 1408, 1410 along the length of the jaw portion 1402. Referring to Figure 14C, when the jaw portion is positioned in contact with the target tissue 1412, the target tissue 1412 may allow contact with the electrodes 1404, 1406 by deforming the insulators 1408, 1410 (e.g., generally laterally) to expose the electrodes 1404, 1406. When the target tissue extends substantially the entire length of the jaw portion, substantially the entire length of the electrodes 1404, 1406 may be exposed for contact with the target tissue 1412. When the target tissue 1412 is not in contact with the entire length of the jaw portion 1402, only the portion of the electrodes 1404, 1406 adjacent to the target tissue 1412 may be exposed. That is, the portion of the electrodes 1404, 1406 that is not in contact with the target tissue 1412 or that is adjacent to the target tissue 1412 may remain substantially covered by the insulators 1408, 1410. Therefore, the insulators 1408 and 1410 may reduce the possibility of arcing associated with the portions of electrodes 1404 and 1406 that are not in contact with the target tissue 1412.

[0106] Referring to Figure 15A, an alternative configuration example is shown that includes a jaw portion having selectively insulated electrodes. Figures 15B and 15C are cross-sectional views of the embodiment of Figure 15A when the electrodes are in contact with target tissue. In the shown embodiments, the jaw portion 1502 may include one or more electrodes 1504, 1506 on the tissue engagement surface. Referring to Figure 15B, when the jaw portion 1502 is not in contact with tissue, one or more deformable insulators 1508, 1510 may at least partially cover one or more electrodes 1504, 1506. In some embodiments, the insulators 1508, 1510 may be constructed from flexible silicone or other suitable materials. In the shown embodiments, each insulator 1508, 1510 substantially covers the entire length of each electrode 1504, 1506, and a central slit runs between the inner surfaces of the insulators 1508, 1510 along the length of the jaw portion 1502. Referring to Figure 15C, when the jaw portion is positioned in contact with the target tissue 1512, the target tissue 1512 may allow contact between the target tissue 1512 and the electrodes 1504 and 1506 by deforming the insulators 1508 and 1510 (e.g., generally laterally) to expose the electrodes 1504 and 1506. When the target tissue extends substantially along the entire length of the jaw portion, substantially the entire length of the electrodes 1504 and 1506 may be exposed for contact with the target tissue 1512. When the target tissue 1512 is not in contact with the entire length of the jaw portion 1502, only the portions of the electrodes 1504 and 1506 adjacent to the target tissue 1512 will be exposed. That is, portions of the electrodes 1504 and 1506 that are not in contact with the target tissue 1512 or that are adjacent to the target tissue 1512 may remain substantially covered by the insulators 1508 and 1510. Therefore, the insulators 1508 and 1510 may reduce the possibility of arcing associated with portions of electrodes 1504 and 1506 that are not in contact with the target tissue 1512. In the embodiments shown, the insulators 1508 and 1510 in Figures 15A to 15C differ from the insulators 1408 and 1410 in Figures 14A to 14C in that the insulators 1508 and 1510 are arranged on elongated base portions 1514 and 1516 that may extend longitudinally along the lateral edges of the jaw portion 1502.In the embodiments shown, the insulators 1508 and 1510 may be integrally formed with their respective base portions 1514 and 1516. In some embodiments, the body of the jaw portion 1502 may be constructed from a relatively rigid material, and / or the base portions 1514 and 1516 and / or the insulators 1508 and 1510 may be constructed from a relatively flexible, deformable material.

[0107] Referring to Figure 16A, an alternative configuration example is shown that includes a jaw portion having selectively insulated electrodes. Figures 16B and 16C are cross-sectional views of the embodiment of Figure 16A when one or more electrodes are in contact with target tissue. In the shown embodiments, the jaw portion 1602 may include one or more electrodes 1604 on the tissue engagement surface. Referring to Figure 16B, when the jaw portion 1602 is not in contact with tissue, one or more deformable insulators 1606, 1608 may at least partially cover one or more electrodes 1604. In some embodiments, the insulators 1606, 1608 may be constructed from, for example, flexible silicone or other suitable material. In the shown embodiments, each insulator 1606, 1608 substantially covers the entire length of the electrode 1604, and a central slit runs between the inner surfaces of the insulators 1606, 1608 along the length of the jaw portion 1602. Referring to Figure 16C, when the jaw portion is positioned in contact with the target tissue 1610, the target tissue 1610 may allow contact with the electrode 1604 by deforming the insulators 1606, 1608 (e.g., generally laterally) to expose the electrode 1604. When the target tissue extends substantially the entire length of the jaw portion, substantially the entire length of the electrode 1604 may be exposed for contact with the target tissue 1610. When the target tissue 1610 is not in contact with the entire length of the jaw portion 1602, only the portion of the electrode 1604 adjacent to the target tissue 1610 may be exposed. That is, portions of the electrode 1604 that are not in contact with the target tissue 1610 or that are adjacent to the target tissue 1610 may remain substantially covered by the insulators 1606, 1608. Thus, the insulators 1606, 1608 may reduce the possibility of arcing associated with portions of the electrode 1604 that are not in contact with the target tissue 1610. In some embodiments, the insulators 1606 and 1608 may be arranged on elongated base portions 1612 and 1614 that may extend longitudinally along the lateral edges of the jaw portion 1602. In the shown embodiments, the insulators 1606 and 1608 may be integrally formed with the base portions 1612 and 1614.In some embodiments, the body of the jaw portion 1602 may be constructed from a relatively rigid material, and / or the base portions 1612, 1614 and / or the insulators 1606, 1608 may be constructed from a relatively flexible, deformable material. In the embodiments shown, the configurations in Figures 16A-16C may differ from those in Figures 15A-15C in that they may include one elongated electrode 1604 instead of a pair of generally parallel elongated electrodes 1504, 1506.

[0108] Referring to Figure 17A, an alternative configuration example is shown that includes a jaw portion having selectively insulated electrodes. Figures 17B and 17C are cross-sectional views of the embodiment of Figure 17A when the electrodes are in contact with target tissue. In the embodiments shown, the jaw portion 1702 may include one or more electrodes 1704 on the tissue engagement surface and one or more deformable insulators 1706, 1708, which are generally similar to the corresponding components described with reference to Figures 16A-16C. In the embodiments shown in Figures 17A-17C, the body of the jaw portion 1702 may be formed integrally with the insulators 1706, 1708. In some embodiments, the body of the jaw portion 1702 may be formed of the same material as the insulators 1706, 1708. Thus, in some embodiments, the body of the jaw portion 1702 may be deformable. In some embodiments, the body of the jaw portion 1702 may be mounted on a rigid or more rigid jaw backer when assembled into a clamp-type configuration.

[0109] Referring to Figure 18A, an alternative configuration example is shown that includes a jaw portion having selectively insulated electrodes. Figures 18B and 18C are cross-sectional views of the embodiment of Figure 18A when the electrodes are in contact with target tissue. In the shown embodiments, the jaw portion 1802 may include one or more electrodes 1804 on the tissue engagement surface and one or more deformable insulators 1806, 1808, which are generally similar to the corresponding components described with reference to Figures 16A-16C. In the shown embodiments, the insulators 1806, 1808 may be adjacent to, for example, the electrodes 1804 and at least partially overlap them. In the shown embodiments, the body of the jaw portion 1802 may be formed integrally with the insulators 1806, 1808. In some embodiments, the body of the jaw portion 1802 may be formed of the same material as the insulators 1806, 1808. Thus, in some embodiments, the body of the jaw portion 1802 may be deformable. In some embodiments, the body of the jaw portion 1802 may be mounted on a rigid or more rigid jaw backer when assembled into a clamp-type configuration. In the embodiments shown, the configurations in Figures 17A-17C further differ from those in Figures 18A-18C in that the jaw portion 1702 may generally be curved in the longitudinal direction, whereas the jaw portion 1802 may generally be straight in the longitudinal direction.

[0110] Figure 18D shows an example embodiment including a deformable insulator 1810 positioned around an electrode 1812 positioned on a rigid backplate 1814. In the shown embodiment, the backplate may include one or more longitudinal grooves 1816 for, for example, receiving the electrode therein. In some alternative embodiments, the backplate 1814 may generally be flat (e.g., without grooves).

[0111] Figure 18E shows an example embodiment including spaced struts 1818 that support electrodes 1820 within a deformable insulator 1822. The struts 1818 may be mechanically coupled to a relatively rigid partial support component, such as a jaw structure of a clamp-type PFA device. In some embodiments, the insulator 1822 may include one or more openings configured to receive the struts 1818.

[0112] Some embodiments may include one or more leading ridge mechanisms configured to facilitate the movement of insulating material, for example, to expose an electrode. For example, one or more ridge mechanisms 1824 on the tissue contact surface 1826 shown in Figure 18F. These mechanisms may be positioned to contact the target tissue before other parts of the insulators 1828, 1830, thereby causing the insulators 1828, 1830 to move away from the electrode 1832 and expose the electrode 1832.

[0113] Figure 18G shows an alternative embodiment in which the deformable insulator 1834 may be segmented. In the shown embodiment, in addition to the longitudinal slit 1838, one or more generally lateral cross-cuts 1836 (e.g., slits) are provided. Thus, the segments 1840 of the insulator 1834 that are in contact with the tissue may more easily separate from the electrode 1842, while the segments 1840 of the insulator 1834 that are not in contact with the tissue may remain in place (e.g., at least partially covering the electrode 1842).

[0114] This disclosure considers that microbubbles may form when high-voltage electrical pulses are delivered during PFA. Generally, microbubbles may contain multiple thin spheres of liquid, each containing a small pocket of gas. Microbubbles may be formed by, for example, vaporization of the liquid, cavitation, and / or electrolysis. Generally, microbubble formation can be undesirable because, after formation, they can travel through the bloodstream and clog microvessels, potentially leading to unintended tissue damage and / or organ dysfunction. In addition, microbubbles may cause silent cerebral events, such as brain injury that occurs without any noticeable symptoms during a medical procedure or intervention.

[0115] Although PFA is generally considered non-thermal because it does not rely on high temperatures to ablate tissue, this disclosure considers that in some situations, the application of PFA energy may result in tissue heating. Generally, the duration, intensity, and / or frequency of the PFA signal may affect the degree of tissue heating. In some situations, the composition and / or structure of the tissue may affect heating, such as how quickly heat can be transferred and dissipated. In some situations, cooling methods may be used to lower the tissue temperature. For example, the possibility of undesirable heating may be reduced by irrigation with a cooling fluid, such as saline solution, and / or the use of a heat sink or cooling catheter. Alternatively, in embodiments of a vacuum pod, a fluid flow through the vacuum pod may be used to cool the electrodes and tissue surface. Electrode pair alternating switching may be used for on / off electrode duty cycles.

[0116] This disclosure acknowledges that PFA and RF ablation may be associated with different mechanisms of action and / or different possible advantages and / or disadvantages. In some embodiments of at least some aspects of this disclosure, these differences may be used to facilitate desired results. For example, some exemplary embodiments may be configured to perform both PFA and RF ablation on a particular target tissue. In some embodiments, PFA and RF ablation may be performed using at least one common electrode. In some embodiments, PFA and RF ablation may be performed using different electrodes. In general, any systems, devices, electrodes, isolation configurations, etc., described herein may be used in connection with the delivery of either or both RF and PFA.

[0117] For example, in some embodiments, the user may be able to select between PFA alone and RF alone. Thus, the user may select the desired ablation modality for a particular ablation. For example, a surgeon may select PFA and / or RF ablation at least partially based on the location of the ablation (e.g., adjacent to sensitive non-target tissue) and / or the type of target tissue.

[0118] Some embodiments may be configured to create a lesion using both PFA and RF ablation modalities. For example, in some situations, it may be advantageous to perform PFA on the endocardium in connection with epicardial RF ablation. The resulting ablation may be partially PFA and partially RF in any mixing ratio that fits within the tissue thickness to create a lesion of full thickness. PFA may extend from one surface into the tissue thickness, while RF may extend from the opposite surface. Alternatively, the RF lesion may be formed partially or entirely in the center of the tissue thickness, and PF may complete the lesion outward toward the tissue surface. Such mixed modality approaches may create transmural lesions in the target tissue while benefiting from the advantages associated with each individual modality. For example, in some situations, using PFA on the endocardium may avoid some of the disadvantages that may result from using RF ablation in close proximity to blood, and / or using RF ablation on the epicardium may facilitate thermal ablation of some target autonomic tissues. In some embodiments, PFA may be applied in two directions (e.g., endocardium and epicardium), and RF ablation may be applied in one direction (e.g., epicardium only). In some embodiments, both PFA and RF ablation may be performed over substantially the entire thickness of the tissue.

[0119] In some embodiments, PFA may be performed before RF ablation, thereby facilitating faster RF ablation due to the increased tissue conductivity provided by PFA. In some embodiments, RF ablation may be performed before PFA. In some embodiments, RF and PF ablation may be performed simultaneously by interrupted alternating and / or overlapping deliveries.

[0120] This disclosure acknowledges that PFA and cryoablation may be associated with different mechanisms of action and / or different advantages and disadvantages. In some embodiments of at least some aspects of this disclosure, these differences may be used to facilitate the desired results. For example, some exemplary embodiments may be configured to perform both PFA and cryoablation, not necessarily simultaneously.

[0121] For example, in some embodiments, the user may be able to select between PFA alone and cryoablation alone. Thus, the user may select the desired ablation modality for a particular ablation. For example, a surgeon may select PFA and / or cryoablation based at least partially on the location of the ablation and / or the type of target tissue.

[0122] Some embodiments may be configured to induce damage using both PFA and cryoablation modalities. Such mixed modality approaches may induce transmural damage in the target tissue while benefiting from the advantages associated with each individual modality. In some embodiments, PFA may be performed before cryoablation. In some embodiments, cryoablation may be performed before PFA. In some embodiments, PFA may be performed during cryoablation, at any point during cryodelivery, or throughout the entire duration. Temperature measurements or setpoints may or may not be used as feedback. In some embodiments, cryoablation may be applied at a therapeutic level; that is, the cryoablation itself may be sufficient to result in permanent damage formation in the target tissue. In other embodiments, cryoablation may be applied at a subthermal level; that is, the cryoablation itself may affect the tissue in a substantially reversible manner. In some situations, performing cryoablation before PFA may affect (e.g., improve or accelerate) the subsequent PFA. For example, the cryoablated target tissue may receive PFA energy more efficiently by being completely reheated or still cooled to below body temperature, or the PFA energy may be conducted through the target tissue in a different manner, or the lower tissue temperature achieved by cryoablation may offset or reduce the temperature increase caused by the use of PFA.

[0123] This disclosure considers that, in some circumstances, PFA-induced damage may not be readily visible in the target tissue immediately or for a short period after PFA energy delivery. In some cases, due to cell death and tissue response, PFA damage may not be readily visible or detectable for several days to several weeks. Therefore, the presence, location, and / or extent of PFA damage may not be readily apparent or detectable to the user during the ablation procedure. This disclosure considers that this lack of immediate visibility and / or detectability may increase the difficulty in creating elongated, continuous damage formed by performing multiple overlapping ablations.

[0124] Returning to Figure 1, in some embodiments of at least some aspects of the present disclosure, the PFA device 104 may operate to immediately induce a visible thermal injury in connection with inducing a PFA injury. For example, a PFA injury may be formed, and then a corresponding thermal injury may be formed using RF ablation and / or cryoablation (e.g., without moving the end effector 132 between the PFA and RF or cryoablation). Alternatively, a localized thermal injury may be induced using high-voltage PFA in addition to ablating the surrounding tissue by irreversible electroporation. Alternatively, after PFA is performed, a high-voltage pulse or pulse train may follow that may not electrically porate the tissue but may induce a thermal injury in the tissue. In some embodiments, the thermally induced injury may be advantageous for ablating the surface nerve plexus.

[0125] Referring to Figure 19A, an example of a damaged area including a PFA zone 1902 and a thermal ablation zone 1904 is shown. Figure 19B is a cross-sectional view of the damaged area in Figure 19A.

[0126] Figure 19C is a top view of an example of damage caused using a PFA+RF device having a PFA zone 1902 and a thermal ablation zone 1904 as shown, according to at least some aspects of the present disclosure.

[0127] Examples of embodiments according to at least some aspects of this disclosure may use various tissue contact configurations.

[0128] Some embodiments may be configured to use a contact force applied by an operator to induce desired tissue contact. For example, the pen-type configuration may be manually held against the target tissue by the operator while PFA energy is being applied. Similarly, a surgical robot may be used to apply the PFA device to the target tissue.

[0129] Some embodiments using a mechanical configuration may generally be constructed in the form of a clamp. See, for example, the embodiment in Figure 2. Some embodiments using a mechanical configuration may use a snare. Figure 19D shows snare clamp example 1910.

[0130] In some embodiments, screws may be used for tissue engagement. Figure 19E shows an example 1920 of a generally helical screw engagement component for a jaw or electrode 1922, configured to penetrate target tissue 1924.

[0131] Some embodiments may utilize magnetic components that cooperate for tissue engagement. For example, various embodiments described in International Application PCT / US2022 / 082057, filed on December 20, 2022, published on July 6, 2023, as International Publication WO2023129842, which are incorporated herein by reference, entitled “Magnetically Coupled Ablation Components,” may be used in connection with embodiments of at least some aspects of this disclosure.

[0132] Some embodiments may be configured to create holes in the tissue. See, for example, the needle-type embodiments shown in Figures 4A-4C.

[0133] Some embodiments may be configured to use a vacuum for tissue engagement. See, for example, the embodiments shown in Figures 3A and 3B.

[0134] Some embodiments may use tissue freezing for tissue engagement. For example, an embodiment including cryogenic capability may be placed in contact with the target tissue. The tissue may be therapeutically or subthermally frozen at least partially or significantly cooled so that the tissue engagement probe adheres to the target tissue. PFA energy may be applied while the probe maintains contact by adhering to the target tissue. After the desired PFA and / or cryogenic effect has been achieved, the tissue may be thawed or heated and the probe may be removed from the tissue.

[0135] Referring to Figure 20, some embodiments may use one or more expandable structures to generate tissue contact force. In the shown embodiments, the PFA device 2002 may include one or more electrodes 2004, 2006 and / or one or more expandable structures 2008 on the tissue engagement surface. In the shown embodiments, the expandable structure 2008 may generally be positioned opposite the electrodes 2004, 2006. During operation, the PFA device 2002 may be positioned between the target tissue 2010 and the opposing tissue 2012. The expandable structure 2008 may expand from a flattened configuration (dashed line) to an expanded configuration (solid line). By expanding the expandable structure 2008 and bringing it into contact with the opposing tissue 2012, the tissue engagement surface including the electrodes 2004, 2006 may be pressed against the target tissue 2010. The expansion of the expandable structure 2008 may be controlled as needed to achieve the desired contact between the electrodes 2004, 2006 and the target tissue 2010. The expandable structure 2008 may be deflated when one or more ablations are completed. In some embodiments, the expandable structure may be inflatable by a fluid (e.g., gas and / or liquid). In some embodiments, the target tissue 2010 may include myocardium, and the opposing tissue 2012 may include pericardium.

[0136] Some embodiments of at least some aspects of this disclosure may include multiple electrodes. Unless otherwise expressly stated, generally, any embodiment described herein may provide one or more electrodes. While some embodiments may be described in relation to the specific exemplary use of certain individual electrodes, it should be understood that any electrode in any embodiment may be used for any purpose, regardless of how it is described in a particular example. For example, an electrode described as an ablation electrode may be used for pacing, stimulation, mapping, and / or detection in some situations. Similarly, an electrode described as a pacing, stimulation, mapping, and / or detection electrode may be used for ablation in certain situations. Furthermore, it should be understood that any embodiment of at least some aspects of this disclosure may include additional electrodes for, for example, pacing, stimulation, mapping, and / or detection, whether or not they are specifically described herein in relation to a particular embodiment.

[0137] Some embodiments of at least some aspects of this disclosure may be used in connection with procedures directed toward the treatment of various arrhythmias. For example, ablation may be performed on various target tissues, including the autonomic nervous system of the heart (e.g., ganglionated plexuses, ganglia, and / or conduction pathways) and / or cardiac substantive tissue (e.g., atria and / or ventricles).

[0138] Generally, performing procedures involving any part of the heart using the apparatus and / or methods disclosed herein is within the scope of this disclosure. For example, procedures involving the right atrium may be performed in connection with treatment for inadequate sinus tachycardia (e.g., crista line, inferior vena cava, and / or superior vena cava), atrial fibrillation (e.g., Cox maze injury - right side), and / or Wolff-Parkinson-White syndrome. For example, procedures involving the right ventricle may be performed in connection with treatment for ventricular tachycardia (e.g., posterior wall of the right ventricle, lateral free wall of the right ventricle, anterior part of the right ventricle, septum, right ventricular papillary muscle, and / or right ventricular outflow tract), partial ventricular contraction (e.g., septum of the right ventricular outflow tract, basal right ventricle, and / or right ventricular outflow tract free wall), and / or Brugada syndrome (e.g., right ventricular outflow tract). Procedures involving the left atrium may be performed in connection with treatment for atrial fibrillation (e.g., Marshall's ligament, roof and floor lines, posterior left atrial wall, isthmus line, and / or autonomic nerves (ganglion plexus)) and / or left atrial appendage isolation (e.g., left atrial appendage foramen). Procedures involving the left ventricle may be performed in connection with, for example, syncope (e.g., autonomic nerves (ganglion plexus)), atrial tachycardia (e.g., somewhere in the left ventricle), atrial flutter (e.g., mitral valve), Wolff-Parkinson-White syndrome (e.g., atrioventricular groove), partial ventricular contraction (e.g., left ventricular outflow tract and / or aortic root), hypertension (e.g., somewhere in the left ventricle), and / or ventricular tachycardia (e.g., posterior left ventricle, left ventricular lateral free wall, left ventricle, septum, left ventricular papillary muscle, and / or left ventricular apex). For example, procedures involving the right / left ventricular septum may be performed in relation to ventricular tachycardia (e.g., combined right and left ventricular injuries). It should be understood that the above list is merely an example and should not be considered limiting.

[0139] Some embodiments of at least some aspects of this disclosure may be used in connection with nerve block procedures. For example, peripheral nerves may be ablated to produce a temporary but fully reversible loss of sensory nerve function. Ablation may cause axonal rupture, which is a level of nerve damage according to Seddon's classification, where the axon and myelin are destroyed, but at least some of the surrounding tubular structures, such as the endoneurium, perineurium, bundles, and / or epineurium, remain intact. Subsequent Wallerian degeneration is a process in which the entire length of the nerve segment distal to the ablated injury is destroyed, which takes about a week. Nerve regeneration begins with the proximal segment and continues at an average rate of 1–3 mm / day, following the intact structural components, until the tissue is reinnervated. Depending on how prominent the ablated injury is in the tissue, this process may take several weeks to several months. Since such procedures preserve the structure of the nerve, they will not be associated with the development of a neuroma.

[0140] Local analgesia for nerves (e.g., intercostal nerves) is intended for the management of pain caused by discomfort resulting from nerve damage by incisions, surgical muscle destruction, surgical instruments (e.g., retractors) and surgical retainers (e.g., sutures), as well as for any openings created by tubes or trocar sites. In exemplary form, one exemplary process involves nerve ablation for pain after thoracotomy, including ablation of intercostal nerves. What follows are exemplary procedures for performing nerve blocks in response to thoracotomy, which are effective for pain management and can be applied to any nerve in the body of an animal.

[0141] It may be recommended to perform nerve ablation procedures as early as possible in the surgical procedure, for example, before or immediately after making a thoracotomy. Target nerves, such as intercostal nerves, may be located in the margin of the incised intercostal space (e.g., between the ribs), preferably around the membranous portion of the medial and internal intercostal muscles. A location proximal to the lateral cutaneous branch, but at least 2 cm from the ganglion and / or at least 4 cm from the vertebra, may be selected.

[0142] The ablation device may be positioned directly at the apex of the nerve with a slight angle to optionally ensure that the nerve is directly beneath the ablation component. Prior to ablation, the ablation device may be pressed into the rib groove with sufficient pressure to produce tissue compression for stability and reduction of local perfusion. The appropriate pressure may be sufficient to produce blanching when pressed against the skin. In some embodiments, a needle-type PFA device may be used. In some embodiments, a pen-type PFA device may be used. In some embodiments, a minimally invasive PFA device may be used, such as one that provides vacuum stabilization capability.

[0143] After positioning the ablation device to be in contact with or in close proximity to the nerve, the ablation device may be activated to ablate the nerve. A series of ablations may be repeated at different locations on the same nerve (or at different locations on different nerves), and may be repeated as needed to achieve adequate pain management outcomes. In general, some exemplary nerve ablation procedures as described above may be repeated for intercostal nerves located in each of the third through ninth intercostal spaces.

[0144] In some method examples according to at least some aspects of the present disclosure, nerve ablation may be provided in connection with the amputation of the limb and / or extremity. The present disclosure considers that in some circumstances, nerve ablation may be performed at some time after the amputation procedure has been performed (e.g., weeks, months, or years later), for example, after the onset of significant pain in the patient.

[0145] In some method examples according to at least some aspects of this disclosure, nerve ablation may be performed concurrently with the cutting procedure. For example, the nerve may be identified during the cutting procedure. The nerve may be cut after being separated from adjacent tissue, such as a nearby blood vessel. The nerve cutting site may be determined. In some cases, the nerve may regress distally. For example, the nerve ablation site may be determined proximal to the nerve cutting site. The nerve may be engaged with the ablation site using, for example, an ablation device. The nerve may be ablated by using an ablation device to make contact with a pen-like device or by capturing it between clamp-like or gripper-like devices. In some cases, one or more ablation cycles may be performed. The ablation device may be removed from the nerve. The nerve may be cut at the nerve cutting site.

[0146] Therefore, mechanical damage to the nerve (e.g., nerve transection at the transection site) may be located at a certain distance distal to the nerve ablation site. Because the nerve can slowly regenerate distally from the ablation site toward the transection site, it may take a considerable amount of time for the regenerated nerve to reach the transection site. During this time, the damaged tissue adjacent to the transection site may heal. As a result, when the regenerated nerve reaches the transection site, it may be surrounded by relatively healed tissue, thus reducing the likelihood and / or severity of neuromatosis. In addition, the need for further postoperative pain management may be reduced by the reduction of pain and other sensations from distal to the ablation site during the time required for nerve regeneration.

[0147] Some embodiments of at least some aspects of this disclosure may be used in connection with the ablation of target tissues other than cardiac and nervous tissue. For example, some embodiments may be used in connection with the ablation of tissues including liver tissue, kidney tissue, and / or brain tissue.

[0148] Referring to Figure 21, a simplified block diagram of an example of an equipment configuration that may be used to use various PFA and / or RF ablation devices and / or algorithms, for example, according to at least some aspects of this disclosure is shown.

[0149] Referring to Figure 22, an example PFA device 2200 for vacuum stabilization and / or unipolar energy delivery may be configured. The embodiments shown may be constructed and / or operated in general similar manner to those described in U.S. Patent No. 10,413,355 issued September 17, 2019, entitled “VACUUM COAGULATION PROBES,” which is incorporated herein by reference. Referring to Figures 5R and 22, some embodiments may include a generally helical electrode 2202 disposed within a vacuum pod, which may engage with target tissue using vacuum and / or be supplied with saline solution to facilitate cooling and / or bonding.

[0150] Referring to Figure 23, in some embodiments of at least some aspects of this disclosure, one or more PFA energy parameters, such as those described herein, may be modified at least in part based on one or more measured parameters. For example, one or more measurements may be taken before the delivery of PFA energy, and these measurements may be used to determine one or more PFA energy parameters to be delivered. In some embodiments, one or more measurements may be taken in connection with the delivery of PFA energy (e.g., during and / or between PFA pulses), and these measurements may be used to determine whether to continue or stop the delivery of PFA energy, and / or whether to adjust one or more PFA energy parameters.

[0151] In some embodiments, including clamp-type PFA devices, one or more parameters related to the distance between jaws may be used to at least partially determine one or more PFA energy parameters. For example, one or more PFA energy parameters may be controlled as a function of parameters related to the distance between opposing jaws. For example, in one embodiment, the distance between jaws may be measured and used to determine the PFA energy potential (e.g., the maximum voltage delivered). In some such embodiments, a larger measured jaw distance may result in a larger PFA energy potential. Thus, in some embodiments, a desired transmembrane potential may be achieved over a range of jaw closure distances.

[0152] In some embodiments, at least one PFA energy parameter may increase as the measurement parameter increases. In some embodiments, at least one PFA energy parameter may decrease as the measurement parameter decreases. In some embodiments, at least one PFA energy parameter may increase as the measurement parameter decreases. In some embodiments, at least one PFA energy parameter may decrease as the measurement parameter increases.

[0153] In some embodiments, at least one PFA energy parameter may vary substantially linearly with respect to the measurement parameter. In some embodiments, at least one PFA energy parameter may vary substantially nonlinearly with respect to the measurement parameter.

[0154] For example, without limitation, one or more PFA energy parameters, such as those described herein, may be determined and / or modified based at least in part on one or more measurements of voltage, current, inductance, impedance, conductivity, resistance, or temperature.

[0155] In some embodiments of at least some aspects of this disclosure, one or more PFA energy parameters, such as those described herein, may be modified at least partially based on one or more selected parameters. Such selected parameters may be pre-set when the device or unit is built for a particular end use, or they may be selected by the user before and / or during use. To determine at least partially one or more PFA energy parameters, for example, tissue type, cell density, and / or tissue compressibility may be used.

[0156] In some embodiments, two or more measurement and / or selected parameters may be used in combination to determine one or more PFA energy parameters. For example, a selected tissue type (which may relate to, for example, known tissue compressibility and / or cell density values), a measured jaw closure distance, and / or a measured jaw closure force may be used in combination to at least partially determine at least one PFA energy parameter, such as maximum potential. In some embodiments, two or more measurement and / or selected parameters may be weighted equally in determining at least one PFA energy parameter. In some embodiments, two or more measurement and / or selected parameters may be weighted unequally in determining at least one PFA energy parameter. In some embodiments, different selected and / or measurement parameters may be used to at least partially determine different PFA energy parameters. In some embodiments, different selected and / or measurement parameters may be weighted in different ways in relation to at least partially determining different PFA energy parameters.

[0157] In general, any one or more PFA energy parameters described herein may be determined and / or modified at least in part on the selection and / or measurement of any parameter or condition described herein.

[0158] The following patent references may provide context to this disclosure and are incorporated herein by reference in their entirety: U.S. Patent No. 9,072,518, issued July 7, 2015, entitled "High-Voltage Pulse Ablation Systems and Methods"; U.S. Patent No. 9,474,574, issued October 25, 2016, entitled "Stabilized Ablation Systems and Methods"; U.S. Patent No. 11,628,007, issued April 18, 2023, entitled "CryoProbe"; U.S. Patent No. 10,413,355, issued September 17, 2019, entitled "Vacuum Coagulation Probes"; and "Ablation Devices and Methods of Use U.S. Patent Application Publication No. 2022 / 0133400, published on May 5, 2022, titled "USE); U.S. Patent Application Publication No. 2019 / 0159835, published on May 30, 2019, titled "CRYOPAD"; and International Application PCT / US2022 / 082057, filed on December 20, 2022, published on July 6, 2023, as International Publication No. WO2023129842, titled "MAGNETICALLY COUPLED ABLATION COMPONENTS". Generally, any feature or improvement described herein may be used in connection with the embodiments described herein, and any feature, component, or method described herein may be used in connection with any embodiment described herein.

[0159] Unless otherwise specifically indicated, any description of any structure, function, and / or method relating to any exemplary embodiment herein will be understood to apply to any other exemplary embodiment. More generally, it is within the scope of this disclosure to use any one or more features of any one or more embodiments described herein in relation to any one or more features of any other embodiments described herein. Accordingly, any combination of any features or embodiments described herein is within the scope of this disclosure.

[0160] From the above description and summary of the invention, it should be apparent to those skilled in the art that while the methods and apparatus described herein constitute examples of embodiments provided herein, the scope of the disclosure contained herein is not limited to the exact embodiments described above, and modifications may be made without departing from the scope defined by the following claims. Similarly, it should be understood that inherent and / or unexpected advantages may exist even if they are not explicitly considered herein, and therefore, it is not necessary to satisfy any or all of the identified advantages or objectives disclosed herein in order to be within the scope of the claims.

Claims

1. An electrode including an electrode surface for delivering electric current to anatomical tissue, The system includes a deformable insulator that selectively covers the electrode surface, wherein the deformable insulator is configured to deform when it comes into contact with the anatomical tissue, thereby exposing the electrode surface. Pulse field ablation effector.

2. The pulsed-field ablation effector according to claim 1, wherein the deformable insulator includes a slit at least partially occupied by the electrode.

3. The slit extends longitudinally along the main dimensions of the deformable insulator, The electrode extends longitudinally within the slit over most of its length. The pulse-field ablation effector according to claim 2.

4. The pulse-field ablation effector according to claim 1, further comprising a rigid backer, wherein the electrodes and a deformable insulator are mounted on the rigid backer.

5. The pulse-field ablation effector according to claim 4, wherein the deformable insulator is mounted to the rigid backer using a living hinge.

6. The pulse-field ablation effector according to claim 4, wherein the deformable insulator is embedded within the rigid backer.

7. The pulse-field ablation effector according to claim 1, wherein the deformable insulator includes a bulging mechanism configured to concentrate contact force due to contact with the anatomical tissue, thereby accelerating the deformation of the deformable insulator.

8. The pulsed-field ablation effector according to claim 7, wherein the elevation mechanism includes a plurality of elevation mechanisms, and at least two of the plurality of elevation mechanisms are located on the opposite side of the electrode.

9. The aforementioned plurality of raised mechanisms include longitudinal ribs, The longitudinal ribs generally extend parallel to the electrodes. The pulse-field ablation effector according to claim 7.

10. The pulse-field ablation effector according to claim 1, wherein the deformable insulator includes an elastomer.

11. The pulsed-field ablation effector according to claim 10, wherein the elastomer contains silicone.

12. The electrode is segmented into multiple electrodes, The deformable insulator is segmented into multiple deformable insulator portions, Each of the plurality of electrodes includes an electrode surface selectively covered by at least one of the plurality of deformable insulating portions, Of the plurality of deformable insulating portions, only those that come into contact with the anatomical tissue deform, exposing the portion of the plurality of electrodes that was covered by the contacting plurality of deformable insulating portions. The pulse-field ablation effector according to claim 1.

13. The deformable insulator is segmented into multiple deformable insulator portions, The electrode surface is selectively covered by at least one of the plurality of deformable insulating portions, Only the portion of the plurality of deformable insulating material that is in contact with the anatomical tissue deforms, exposing the side surface of the electrode surface covered by the contacting portion of the plurality of deformable insulating material. The pulse-field ablation effector according to claim 1.

14. The pulsed-field ablation effector according to claim 1, further comprising a cryogenic conduit configured to supply cryogenic fluid to the cryogenic tissue contact area.

15. The pulsed-field ablation effector according to claim 14, wherein the cryogenic tissue contact portion includes the electrode surface of the electrode.

16. The pulsed-field ablation effector according to claim 1, further comprising radio frequency electrodes adapted to deliver radio frequency energy to the anatomical tissue.

17. The pulse-field ablation effector according to claim 16, wherein the radio frequency electrode is selectively covered with the deformable insulator.

18. A method for performing pulsed-field tissue ablation, wherein the method is Repositioning a pulsed-field ablation effector in close proximity to target tissue, wherein the pulsed-field ablation effector includes an electrode having an ablation surface covered with a deformable insulator. Repositioning the pulsed-field ablation effector so that it is in sufficient contact with the target tissue, wherein sufficient contact with the target tissue deforms the deformable insulator to expose the ablation surface of the electrode that was previously covered by the deformable insulator. When the electrode is in sufficient contact with the target tissue, an electric current is supplied to the electrode to induce electroporation of the target tissue. A method comprising repositioning the pulsed-field ablation effector such that it is no longer in sufficient contact with the target tissue, the insufficient contact with the target tissue causing the deformable insulator to deform and cover the previously uncovered ablation surface of the electrode.

19. The target tissue is cardiac tissue, The aforementioned contact is epicardial contact. The method according to claim 18.

20. The aforementioned target tissue is nerve tissue, The aforementioned contact is with at least one of an intact nerve and a severed nerve. The method according to claim 18.

21. The target tissue is the intercostal nerve. The aforementioned method is performed simultaneously with thoracotomy. The method according to claim 18.

22. The target tissue is cardiac tissue, The aforementioned contact is endocardial contact. The method according to claim 18.

23. The pulsed field ablation effector includes a first jaw portion and a second jaw portion, and the electrodes include a first electrode portion in the first jaw portion and a second electrode portion in the second jaw portion. The method according to claim 18, wherein repositioning the pulsed-field ablation effector to be in sufficient contact with the target tissue includes bringing the first electrode portion into contact with epicardial tissue and the second electrode portion into contact with endocardial tissue, such that sufficient contact with the epicardial and endocardial tissues deforms the deformable insulator to expose the first and second electrode portions that were previously covered by the deformable insulator.

24. Performing cryoablation simultaneously with the electroporation causes destruction of the target tissue or tissue adjacent to it. The method according to claim 18, further comprising:

25. By performing radio frequency ablation simultaneously with the electroporation, the destruction of the target tissue or tissue adjacent to it is induced. The method according to claim 18, further comprising:

26. When there is insufficient contact between the target tissue and the deformable insulator, the deformable insulator is located between the ablation surface of the electrode and the target tissue. When sufficient contact occurs between the target tissue and the deformable insulator, the deformable insulator is no longer between the ablation surface of the electrode and the target tissue. The method according to claim 18.

27. The method according to claim 26, wherein when the target tissue and the deformable insulator are in sufficient contact, the tissue contact surface of the electrode emerges from within the deformable insulator.

28. The electrode is segmented into a plurality of electrodes, and each of the plurality of electrodes has a tissue contact surface. The deformable insulator is segmented into a plurality of deformable insulator portions, and each of the plurality of electrodes is selectively covered by at least one of the plurality of deformable insulator portions. When sufficient contact occurs between the target tissue and each of the plurality of deformable insulating portions, each of the plurality of deformable insulating portions acts to expose the corresponding tissue contact surface of the plurality of electrodes. The method according to claim 26.

29. The deformable insulator is segmented into a plurality of deformable insulator portions, and the ablation surface is selectively covered by at least one of the plurality of deformable insulator portions. When there is insufficient contact between the target tissue and the deformable insulator, the deformable insulator is located between the ablation surface of the electrode and the target tissue. When sufficient contact occurs between the target tissue and each of the plurality of deformable insulating portions, each of the plurality of deformable insulating portions acts to expose a portion of the ablation surface. The method according to claim 18.

30. A method for suppressing unintended arcing of a pulsed-field ablation electrode, wherein the method is A method comprising covering the pulsed-field ablation electrode with a deformable insulator, wherein the deformable insulator is configured to change its shape between a first shape and a second shape in response to a sufficient external force applied thereto, the first shape covering the tissue contact surface of the pulsed-field ablation electrode, and the second shape not covering the tissue contact surface of the pulsed-field ablation electrode.

31. Any apparatus, method, or combination thereof disclosed herein.

32. Any combination of any two or more prior claims.

33. Any combination of one or more components of a prior claim.

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