Planar end effector for atrial fibrillation ablation by pulse field ablation

Abstract

A catheter with a planar end effector having elongated ablation electrodes configured to provide electrical signals to achieve intravascular resection (IRE) in target tissue is presented. The planar end effector is alignable along the longitudinal axis of the catheter and configured to flex away from the longitudinal axis upon contact with tissue. Bipolar electrical signals can be applied between the elongated ablation electrodes in various combinations to achieve partial invasive ablation (PFA). The end effector may also include diagnostic electrodes configured to receive electrical signals from tissue to map the tissue, paired tissue contact electrodes for determining which portions of the end effector are in contact with the tissue, or reference electrodes configured to measure blood voltage.

Description

Technical Field

[0001] The present invention relates generally to medical devices, and more particularly to catheters configured to ablate tissue by pulsed field ablation. Background Technology

[0002] Arrhythmias, such as atrial fibrillation (AF), occur when a region of the heart tissue abnormally transmits electrical signals to adjacent tissues. This disrupts the normal cardiac cycle and leads to irregular heartbeats. Arrhythmias are treated surgically or via catheter ablation to stop or modify the unwanted transmission of electrical signals from one part of the heart to another.

[0003] Many simultaneous ablation methods utilize radiofrequency (RF) electrical energy to heat tissue. Due to operator skill, RF ablation can have certain rare drawbacks, such as an increased risk of thermal cell injury, which can lead to tissue carbonization, burns, steam bursts, phrenic nerve paralysis, pulmonary vein stenosis, and esophageal fistulas. Cryoablation is an alternative to RF ablation, reducing some of the thermal risks associated with it, but tissue damage can still occur due to the extremely low temperature nature of such devices. Manipulating cryoablation devices and selectively applying cryoablation is generally more challenging than RF ablation; therefore, cryoablation is not feasible in certain anatomical geometries accessible by RF ablation devices.

[0004] Pulsed field ablation (PFA) is a relatively new non-thermal method for ablating cardiac tissue by inducing irreversible electroporation (IRE) in the cells of a target tissue. To achieve IRE, short pulses of a high-voltage electrical signal are delivered to the tissue, and the electrical signal generates irreversible permeability of the cell membrane. Examples of systems and apparatus configured for IRE ablation are disclosed in U.S. Patent Publications Nos. 2021 / 0169550A1, 2021 / 0169567A1, 2021 / 0169568A1, 2021 / 0196372A1, 2021 / 0177503A1, and 2021 / 0186604A1, and U.S. Patent No. 11,540,877, the entire contents of each of which are incorporated herein by reference and are appended to this document.

[0005] Regions of cardiac tissue can be mapped via catheter to identify abnormal electrical signals. Some catheter ablation procedures, particularly those for persistent atrial fibrillation, can be performed using electrophysiological (EP) mapping of target areas of abnormal electrical signals. Such EP mapping may include the use of diagnostic electrodes configured to monitor electrical signals within the cardiovascular system to precisely pinpoint the location of arrhythmogenic, abnormally conductive tissue sites. An example of an EP mapping system is described in U.S. Patent No. 5,738,096, the entire contents of which are incorporated herein by reference. Examples of EP mapping catheters are described in U.S. Patent Nos. 9,907,480, 2018 / 0036078, and 2018 / 0056038, the entire contents of each of which are incorporated herein by reference.

[0006] In addition to EP mapping, some catheter ablation procedures can be performed using image-guided surgery (IGS) systems. IGS systems allow physicians to visually track the catheter's position within the patient's body in real time, relative to images of the patient's anatomy. Some systems offer a combination of EP mapping and IGS functionality, including Biosense Webster, Inc. of Irvine, Calif's CARTO 3. ® system. Summary of the Invention

[0007] A catheter with a planar end effector having elongated ablation electrodes configured to provide electrical signals to achieve intradermal resection (IRE) in target tissue is presented. The planar end effector is alignable along the longitudinal axis of the catheter and configured to flex away from the longitudinal axis upon contact with tissue. Bipolar electrical signals can be applied between the elongated ablation electrodes in various combinations to achieve partial ablation fusion (PFA). The end effector may also include diagnostic electrodes configured to receive electrical signals from tissue to map the tissue, paired tissue contact electrodes for determining which portions of the end effector are in contact with the tissue, reference electrodes configured to measure blood voltage, or combinations thereof. The end effector can provide PFA to generate an ablation foci with a depth of approximately 7.5 mm in a potato model.

[0008] An example end effector of a medical probe includes a planar body and a plurality of ablation electrodes. The planar body has a first side and a second side opposite to the first side, and extends along a longitudinal axis. The plurality of ablation electrodes includes a first ablation electrode and a second ablation electrode, the first ablation electrode being disposed on the first side of the planar body. The end effector is configured to provide a bipolar pulsed field ablation electrical signal between the first ablation electrode and the second ablation electrode. The first and second ablation electrodes each have a corresponding length of at least half the total length of the end effector, the total length being measured from the distal end of the end effector to the distal end of the axis of the medical probe. The corresponding lengths of the first and second ablation electrodes define the distal portion of the end effector.

[0009] An example method for providing a PFA electrical signal to a planar end effector includes: providing a first bipolar pulsed field ablation electrical signal between a first ablation electrode and a second ablation electrode, the first ablation electrode being disposed on a first side of a planar body of the planar end effector, and the second ablation electrode being disposed on a second side of the planar body and not overlapping with the first ablation electrode; and using the planar end effector to generate an ablation foci with a depth of approximately 7.5 mm in a potato model. Attached Figure Description

[0010] Although a claim that specifically points out and clearly claims protection for the subject matter described herein is provided after the specification, it is believed that the subject matter will be better understood through the description of certain examples below in conjunction with the accompanying drawings, in which similar reference numerals denote the same elements. The drawings depict one or more specific embodiments of the apparatus of the invention by way of example only and not by way of limitation.

[0011] Figure 1 This is an illustration of an example of a catheter-based electrophysiological mapping and ablation system.

[0012] Figure 2 This is an illustration of the distal portion of the conduit, including the example end actuator.

[0013] Figure 3 yes Figure 2 An illustration of an enlarged view of the example end effector shown.

[0014] Figure 4 This is an illustration of a first example electrode configuration for an example end effector, which includes an elongated serpentine ablation electrode and a diagnostic electrode positioned next to the ablation electrode.

[0015] Figure 5 This is an illustration of a second example electrode configuration for an example end effector, which includes elongated ablation electrodes segmented into parallel strips and diagnostic electrodes positioned next to the ablation electrodes.

[0016] Figure 6 This is an illustration of a third example electrode configuration for an example end effector, which includes a rectangular elongated ablation electrode but no diagnostic electrode.

[0017] Figure 7 This is an illustration of a fourth example electrode configuration for an example end effector, which includes a rectangular elongated ablation electrode with a diagnostic electrode interruption.

[0018] Figure 8 This is an illustration of an example electrode configuration on one side of an example end effector, which includes an elongated ablation electrode in two ablation electrode regions, a diagnostic electrode located in the two ablation electrode regions, a tissue contact electrode located between the two ablation electrode regions, and a reference electrode located in the proximal region of the illustrated side of the end effector.

[0019] Figure 9A , Figure 9B , Figure 9C and Figure 9D This is an illustration of an alternative configuration of the insulating material in the cross-section of the end effector, wherein... Figure 9A Configured to have an opening in the end effector, such as Figure 8 As shown; Figure 9B The polymer body region includes the width of the extended end effector; Figure 9C Includes a high-dielectric layer located between each side and extending the width of the end effector; and Figure 9D Includes high-dielectric tiles positioned between each side and configured to overlap to collapse the end effector into the delivery sheath.

[0020] Figure 10 This is an illustration of an end effector, in which ablation electrodes are configured to provide 1,200V pulses between ablation electrode regions.

[0021] Figure 11 It is Figure 10 The illustration shows the processing applied to the end effector of the potato model.

[0022] Figure 12A and Figure 12B The voltage applied across the electrode pair in a transbody configuration is shown, wherein for each pair, one ablation electrode is in contact with the tissue, and the other electrode is located on the opposite side of the end effector body and the central axis of the transbody end effector body is opposite to the first electrode region. Figure 12A and Figure 12B Two different electrode pairings are shown.

[0023] Figure 12C The voltage applied between electrode segments that are used as individually activated electrodes is shown.

[0024] Figure 13 The voltage applied across the ablation electrode pair is shown, wherein both ablation electrodes in the pair are in contact with tissue and positioned across each other across the central axis.

[0025] Figure 14 The voltage applied across the ablation electrode in contact with tissue to the ablation electrode located on the opposite side of the end effector and not in contact with tissue is shown.

[0026] Figure 15A and Figure 15B The voltage applied across the electrode pair is shown, wherein the electrodes in the pair are positioned across each other across the central axis.

[0027] Figure 16 This is an illustration of an example electrode configuration on one side of an example end effector, which includes an elongated ablation electrode in four ablation electrode regions, a diagnostic electrode located in at least two of the ablation electrode regions, a tissue contact electrode located along a longitudinal axis between the ablation electrode regions, and a reference electrode located in a proximal region on the illustrated side of the end effector.

[0028] Figure 17 This is an illustration of an example electrode configuration for an example end effector, which includes an elongated, serpentine ablation electrode.

[0029] Figure 18 This is an illustration of an example electrode configuration for an example end effector, which includes a rectangular elongated ablation electrode.

[0030] Figure 19 This is an illustration of an example electrode configuration for an example end effector, which includes a large-area ablation electrode.

[0031] Figure 20 This is an illustration of an example electrode configuration for an example end effector, in which the ablation electrode is wrapped around a ridge or insulating material surrounding the catheter body.

[0032] Figure 21 This is an illustration of an example electrode configuration for an example end effector, wherein the ablation electrode is partially wrapped around a ridge or insulating material surrounding the catheter body. Detailed Implementation

[0033] The following detailed description should be read in conjunction with the accompanying drawings, in which the same elements are labeled identically across the various drawings. The drawings (not necessarily drawn to scale) depict selected embodiments and are not intended to limit the scope of the invention. The detailed description illustrates the principles of the invention by way of example rather than limitation. This description will clearly enable those skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives, and uses of the invention, including what is currently believed to be the best mode for carrying out the invention. Where any material incorporated herein by reference contains similar terms but differs in definition or description, it should be understood that the definitions and descriptions provided herein will be used to understand the technology disclosed herein.

[0034] As used herein, the term “about” or “approximately” for any numerical value or range indicates appropriate dimensional tolerances that allow a collection of parts or components to achieve the intended purpose as described herein. More specifically, “about” or “approximately” may refer to a range of ±20% of the enumerated value, for example, “about 90%” may refer to a range of 71% to 110% of the value.

[0035] In addition, as used herein, the terms “patient,” “recipient,” “user,” and “subject” refer to any human or animal subject and are not intended to limit the system or method to human use, but the use of the subject matter invention in human patients represents a preferred implementation.

[0036] The term "proximal" refers to the position closer to the operator, while "distal" refers to the position further away from the operator or physician.

[0037] As discussed herein, “operator” and “user” may include physicians, surgeons, technicians, scientists, or any other individual or delivery instrument associated with the delivery of the multi-electrode catheters for treatment disclosed herein.

[0038] As discussed herein, the terms “bipolar” and “monopolar”, when used to refer to IRE ablation protocols, describe different ablation protocols in terms of current path and electric field distribution. “Bipolar” refers to an IRE ablation protocol utilizing a current path between two electrodes, both positioned near the ablation site or inside the organ to be treated; at each of these electrodes, the current density and flux density are typically, but not necessarily, approximately equal. “Monopolar” refers to an IRE ablation protocol utilizing a current path between two electrodes, wherein one electrode with high current density and high flux density is positioned at the ablation site, and one or more second electrodes with relatively low current density and lower flux density are positioned away from the ablation site, such as on a patch typically located outside the body and positioned on the patient's skin.

[0039] As discussed herein, the terms "biphase pulse" and "single-phase pulse" refer to the corresponding electrical signals. A "biphase pulse" is an electrical signal having a positive voltage phase pulse (referred to herein as "positive phase") and a negative voltage phase pulse (referred to herein as "negative phase"). A "single-phase pulse" is an electrical signal having only a positive phase or only a negative phase. Preferably, the system providing the biphase pulse is configured to prevent the application of a direct current (DC) voltage to the patient. For example, the average voltage of the biphase pulse may be zero volts relative to ground or other common reference voltage. Each phase of the biphase and single-phase pulses preferably has a square shape and a substantially constant voltage amplitude for most of the phase duration. The phases of the biphase pulse may be temporally separated by an interphase delay.

[0040] Alternative device and system features, as well as alternative method steps, are presented in the example embodiments herein. As will be understood by those skilled in the art and as expressly stated herein, each given example embodiment presented herein can be modified to include features or method steps presented with different example embodiments herein, wherein such features or steps are compatible with the given example. Such modifications and variations are intended to be included within the scope of the claims.

[0041] A catheter with a planar end effector having an elongated ablation electrode configured to provide an electrical signal to achieve intravascular resection (IRE) in target tissue is presented. The planar end effector is alignable along the longitudinal axis of the catheter and is configured to flex away from the longitudinal axis upon contact with tissue. In some embodiments, the catheter is compatible with an 8.5 French sheath. In some embodiments, the end effector includes a highly insulating layer separating the electrodes on either side of the end effector. To facilitate the collapse of the highly rigid insulator, in some embodiments, the highly insulating layer comprises insulating material tiles that overlap when the end effector retracts into the sheath.

[0042] In some embodiments, the end effector includes four elongated electrode segments (eight elongated electrode segments in total) on each side of the end effector. The elongated electrode segments extend from near the distal end of the end effector to approximately half or more than half the length of the end effector, as measured from its distal end to its proximal end. The end effector may include two electrode regions on each side (four electrode regions in total), such that each electrode region includes two elongated electrode segments connected within the end effector to serve as a single electrode. Alternatively, each electrode segment may be approximately halved, resulting in twice the number of elongated electrode segments, each elongated electrode segment being more than half the length of the elongated electrode segments previously described. This embodiment may include four electrode regions on each side of the end effector, for a total of eight electrode regions.

[0043] PFA can be achieved by applying electrical signals, including pulses for implementing IRE, between electrode pairs. Ablation electrodes can be paired in various ways, and pulses can be applied between different ablation electrode pairs during the same PFA treatment. In some embodiments, an end effector can provide PFA to generate an ablation foci with a depth of approximately 7.5 mm in a potato model. PFA can also be achieved by applying bipolar electrical signals between elongated ablation electrodes in various combinations of pairs.

[0044] Each ablation electrode can be designed with a shape that strikes a trade-off between the following factors: total edge area, total contact area, and open space between the non-ablation electrode. The applicant recognizes that a larger surface area to perimeter ratio can effectively deliver ablation energy while reducing the chance of arcing. The applicant recognizes that avoiding arcing is desirable. Conversely, the serpentine electrode increases the mechanical flexibility of the blade. The applicant recognizes that the flexibility of the electrode can improve tissue contact and catheter life, but the geometry of the serpentine electrode has a lower area to perimeter ratio compared to solid electrodes.

[0045] A challenge with existing ablation catheters (especially PFA catheters) is integrating diagnostic electrodes into the end effector assembly, allowing tissue to be mapped and ablated by the same end effector. In some embodiments, the end effector presented herein may include a diagnostic electrode in addition to the ablation electrode, which is configured to receive electrical signals from the tissue for tissue mapping. With this configuration, the end effector is configured for both mapping and ablation.

[0046] In some implementations, the end effector includes a pair of tissue contact electrodes to determine which parts of the end effector contact the tissue.

[0047] In some embodiments, the end effector includes a reference electrode configured to measure blood voltage. An ablation electrode, diagnostic electrode, or tissue contact electrode may be used as a reference electrode when not in contact with tissue. The end effector may additionally or alternatively include one or more dedicated reference electrodes positioned on a portion of the end effector or shaft near the therapeutic or diagnostic electrode in a location unlikely to come into contact with tissue during the procedure, such as on a proximal portion of the end effector.

[0048] The catheter, end effector, and various aspects of the related methods and systems are described below with respect to the accompanying drawings.

[0049] Figure 1 This is an illustration of an example catheter-based electrophysiological mapping and ablation system 10. System 10 may include multiple catheters that are inserted by a physician 24 through the skin into a chamber or vascular structure of the heart 12 via the patient's vascular system. Typically, a delivery sheath catheter (e.g., 8.5 French) is inserted into the left or right atrium near a desired location within the heart 12. A catheter can then be inserted into the delivery sheath catheter to reach that desired location. Such catheters may include catheters specifically designed for sensing intracardiac electrogram (IEGM) signals, catheters specifically designed for ablation, or catheters specifically designed for both sensing and ablation.

[0050] This document illustrates an example catheter 14 including an end effector 100 configured for sensing PFA. The end effector 100 includes an ablation electrode configured to deliver PFA, as well as optional diagnostic electrodes, tissue contact electrodes, and at least one reference electrode. In some embodiments, the end effector 100 includes a diagnostic electrode configured to map abnormal electrical signals in the heart to detect atrial fibrillation, and thus the end effector 100 can be configured to both sense and map. In such examples, the diagnostic electrode is located on the same side of the end effector and adjacent to the ablation electrode. The physician 24 contacts the end effector 100 against the heart wall to sense a target site in the heart 12 and deliver ablation treatment to the target site without repositioning the end effector between mapping and ablation steps. The electrode arrangement is shown in more detail in subsequent figures. As will be understood by those skilled in the art inspired by the examples presented herein, the electrodes can be used for more than one purpose.

[0051] The magnetic-based position sensor 29 operates in conjunction with a positioning pad 25, which includes a plurality of magnetic coils 32 configured to generate a magnetic field in a predefined workspace. The real-time position of the end effector 100 of the catheter 14 can be tracked based on the magnetic field generated by the positioning pad 25 and sensed by the magnetic-based position sensor 29 disposed in the catheter shaft 90. Details of the magnetic-based position sensing technology are described in U.S. Patents Nos. 5,391,199, 5,443,489, 5,558,091, 6,172,499, 6,239,724, 6,332,089, 6,484,118, 6,618,612, 6,690,963, 6,788,967, and 6,892,091, the entire contents of which are incorporated herein by reference. The end effector 100 may also include one or more induction coils configured to provide electrical signals to a magneto-based position sensing system to determine the position or orientation of the end effector. For example, the end effector 100 may include designs similar to those described in U.S. Patent Publication No. 2024 / 0215894. Figure 5 A and Figure 5 The induction loop or coil shown in B is incorporated herein by reference in its entirety and is appended to this document. In some embodiments, one or more induction coils in the end effector may be used in conjunction with position sensor 29 to determine the position or orientation of the end effector.

[0052] System 10 includes one or more electrode patches 38 positioned to contact the skin of patient 23 to establish a position reference for impedance-based tracking of positioning pad 25 and electrodes 26. For impedance-based tracking, current is directed toward electrodes 26 and sensed at the electrode skin patch 38, allowing triangulation of the position of each electrode via the electrode patch 38. The illustration shows impedance-based tracking electrodes 26 fixed to catheter shaft 90. Additionally, or alternatively, end effector 100 may include one or more impedance-based tracking electrodes. Details of impedance-based position tracking technology are described in U.S. Patents 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182, the entire contents of which are incorporated herein by reference.

[0053] Recorder 11 displays the electrophoresis records captured using surface ECG electrodes 18. Figure 21In an embodiment where the end effector 100 includes diagnostic electrodes, the recorder 11 may further display an intracardiac electrogram (IEGM) derived from electrical signals from the diagnostic electrodes on the end effector 100. The recorder 11 may include pacing capability for pacing rhythms or may be electrically connected to a separate pacemaker.

[0054] System 10 includes an ablation energy generator 50 adapted to conduct ablation energy to an ablation electrode on end effector 100. The energy generated by the ablation energy generator 50 includes pulses for inducing IRE via PFA to perform ablation, and can also be configured to provide radio frequency (RF) energy to heat tissue to facilitate PFA without significant thermal ablation, or to heat tissue for thermal ablation in addition to PFA. The ablation energy generator 50 is preferably configured to provide biphasic pulses to induce IRE while maintaining tissue temperature below the thermal ablation temperature. Alternatively, the ablation energy generator 50 is configured to provide monophasic IRE pulses, monopolar IRE pulses, thermal ablation electrical signals, or combinations thereof. For example, the ablation energy generator 50 may be configured to provide pulses similar to those described in U.S. Patent Publications 2021 / 0169550A1, 2021 / 0177503A1, 2021 / 0186604A1, and 2023 / 0009191A1, as well as U.S. Patent No. 11,540,877B2, the entire contents of which are incorporated herein by reference and are appended to this document. U.S. Patent No. 11,540,877B2 corresponds to U.S. Patent Publication 2021 / 0161592A1, the entire contents of which are incorporated herein by reference.

[0055] For example, as described in U.S. Patent No. 11,540,877B2, generator 50 may be configured to apply a bipolar pulse having an amplitude sufficient to induce an IRE in tissue contacted by the electrode, and RF energy having power sufficient to thermally ablate the tissue contacted by the electrode. In some embodiments, the bipolar pulse sequence comprises pulses having an amplitude of at least 200V, and each bipolar pulse has a duration of less than 20µs. Additionally, or alternatively, the RF signal has a frequency between 350kHz and 500kHz and an amplitude between 10V and 200V. The end effector may also include a temperature sensor, and the electrical signal generator may be configured to apply a signal in response to a temperature measured by the temperature sensor. In some embodiments, the IRE signal may have parameters as indicated in Table 1 of U.S. Patent No. 11,540,877B2. Note that the “bipolar pulse” described in U.S. Patent No. 11,540,877B2 is referred to herein as a “biphase pulse” and relates to the shape of an electrical signal; while the “bipolar pulse” as described herein relates to the arrangement of electrodes for receiving the pulse as defined herein.

[0056] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between catheters, electrophysiological equipment, a power supply, and a workstation 55 for operating the system 10. The electrophysiological equipment of the system 10 may include, for example, multiple catheters, positioning pads 25, surface ECG electrodes 18, electrode patches 38, an ablation energy generator 50, and a recorder 11. Optionally and preferably, the PIU 30 includes processing capabilities for real-time calculation of catheter position and for performing ECG calculations. The PIU 30 can control the generator 50 to provide electrical power to the ablation electrodes of the end effector 100 according to the ablation protocol described above and in the references incorporated herein by reference. The PIU 30, workstation 55, and generator 50 can be collectively considered as an ablation system console having one or more output ports configured to provide ablation energy to the ablation electrodes, one or more processors, and a non-transitory computer-readable medium communicating with the processor to enable the ablation system console to provide ablation energy, as described above and in the examples below.

[0057] In some examples, system 10 also includes a flushing system configured to flush during IRE. In some embodiments, PIU 30 is configured to control the flushing system to provide flushing to the catheter end actuator, similar to that described in U.S. Patent Publication No. 2021 / 0196372A1, the entire contents of which are incorporated herein by reference and appended to this appendix. Flushing fluid may exit the distal end of catheter 100 through a port at the distal end of the shaft or through a hole in the body of the end actuator.

[0058] Workstation 55 includes memory, a processor unit with memory or storage device loaded with appropriate operating software, and user interaction capabilities. Workstation 55 can be configured to provide a variety of functions, optionally including: (1) three-dimensional (3D) modeling of endocardial anatomy and rendering the model or anatomical mapping. Figure 20 (2) To display on display device 27; (3) To overlay on rendered anatomical maps on display device 27 Figure 20 Representative visual markers or images on the screen are compiled from recorded electrophoresis. Figure 21 (2) activating sequence (or other data); (3) displaying the real-time position and orientation of one or more catheters within the cardiac chamber; and (4) displaying the site of interest, such as the location where ablation energy was applied, on the display device 27. A commercial product embodying the elements of system 10 can be CARTO. ™ The system was purchased from Biosense Webster, Inc., 31A Technology Drive, Irvine, CA 92618.

[0059] Figure 2 This is an illustration of the distal portion of the conduit 14, including the example end actuator 100. Figure 2 A first side 101a of an end effector 100 is shown. The end effector has a planar body 140, which has a second side 101b opposite to the first side. Figures 9A to 9D , Figures 12A to 14 The second side 101b preferably, but not necessarily, has electrodes positioned similarly to those on the first side 101a. When similar electrode configurations are arranged on both sides 101a, 101b of the end effector 100, either side can be positioned against tissue during treatment. When one side of the end effector 100 is in contact with tissue, the corresponding electrode on the opposite side is in contact with bodily fluid (e.g., blood) and can serve as a corresponding reference electrode for those electrodes in contact with tissue.

[0060] The end effector 100 includes ablation electrodes, each having longitudinally elongated segments 111a, 111b, 112a, 112b extending along a longitudinal axis AA defined by the conduit shaft 90. The longitudinally elongated segments 111a, 111b on the left side of the longitudinal axis AA form a first ablation electrode 111 (…). Figure 8 The longitudinally elongated segments 112a and 112b on the right side of the longitudinal axis AA form the second ablation electrode 112. Figure 8The ablation electrode has a length L2 that is at least half the total length L1 of the end effector 100, which is measured from the distal end 106 of the end effector to the distal end of the axis 90 of the medical probe 14. The ablation electrodes 111, 112 extend substantially to the distal end 106 of the end effector 100. The length L2 of the ablation electrode defines the distal portion of the end effector 100. The end effector 100 has a width W1 measured from its leftmost and rightmost edges. As shown, the leftmost and rightmost edges of the end effector 100 define parallel side edges of the end effector 100. When in the position of... Figure 2 In the unconstrained configuration shown, the planar body 140 is preferably aligned with the longitudinal axis AA.

[0061] Ablation electrodes 111 and 112 are configured to deliver ablation energy to tissue, as described in more detail elsewhere herein. The second side 101b of the planar body 140 of the end effector 100 preferably includes an ablation electrode having a longitudinally elongated segment opposite the illustrated longitudinally elongated segments 111a, 111b, 112a, 112b electrodes to the plane defined by the planar body 140. In some embodiments, the ablation electrodes 111 and 112 are flush with the planar body 140 to provide the end effector with a first planar surface corresponding to the first side 101a of the planar body and a second planar surface corresponding to the second side 101b of the planar body.

[0062] In some embodiments, when the first side 101a contacts tissue, the ablation electrode on the second side 101b can be used as a corresponding reference electrode for the corresponding relative ablation electrode on the first side 101a, and vice versa. Alternatively, the ablation electrodes on the opposite sides 101a, 101b can be paired to provide a bipolar PFA electrical signal between the paired ablation electrodes. Alternatively, the ablation electrodes on the same side can be paired to provide a bipolar PFA electrical signal between the paired ablation electrodes. The bipolar PFA electrical signal can be monophasic or biphasic.

[0063] The illustrated end effector 100 includes optional diagnostic electrodes 113, 114 located on a first side 101a, which are electrically isolated from ablation electrode segments 111a, 111b, 112a, 112b. The diagnostic electrodes 113, 114 are configured to receive electrical signals from tissue to map cardiac tissue and detect arrhythmias. As shown, the diagnostic electrodes 113, 114 are arranged as a pair, with the first diagnostic electrode 113 on the left side of the longitudinal axis AA and the second diagnostic electrode 114 on the right side of the longitudinal axis AA. The diagnostic electrodes 113, 114 are arranged opposite to each other along an axis DA orthogonal to the longitudinal axis AA. The second side 101b of the planar body 140 of the end effector 100 preferably includes a second pair of diagnostic electrodes opposite to the first pair of diagnostic electrodes relative to the plane defined by the planar body 140.

[0064] The illustrated end effector 100 includes optional tissue contact mass electrodes 115, 116, positioned in pairs with close spacing such that impedance measurements across the respective tissue contact mass electrode pair indicate that both electrodes in the pair are in contact with tissue. As shown, the first side 101a includes a distal tissue contact mass electrode pair 115 disposed near the distal end 106 of the end effector 100 and a central tissue contact mass electrode pair 116 positioned approximately midway along a length L2 of the distal portion of the end effector 100. The paired tissue contact mass electrodes 115, 116 are spaced apart along a longitudinal axis AA. The planar body 140 of the end effector includes a central portion 104 extending along the longitudinal axis AA and centrally extending along a total length L1, the central portion containing no ablation electrodes. As shown, the tissue contact mass electrodes 115, 116 are positioned within this central portion 104. The second side 101b of the planar body 140 of the end effector 100 preferably includes a corresponding tissue contact mass electrode pair, which is opposite to the tissue contact mass electrode pairs 115, 116 on the first side 101a relative to the plane defined by the planar body 140.

[0065] The illustrated end effector 100 includes an optional reference electrode 117 disposed on a first side 101a of the planar body 140. Alternatively, the end effector 100 may include a reference electrode similarly disposed on a second side 101b of the planar body 140. The reference electrodes 117 may be used for either monopolar or bipolar (separate or closed pair) ECG collection, or may serve as a reference. The number may be as few as four per side, but can be increased as needed (and may comply with trace limitations). Signals from the reference electrodes 117 may also be used for contact information to determine which portion of the blade is in contact with or near tissue. The end effector 100 includes a proximal portion defined by a proximal length L3, which does not contain any ablation electrodes. The reference electrodes 117 may be disposed in this proximal portion. As discussed herein, ablation electrodes, diagnostic electrodes, or tissue contact electrodes may be used as reference electrodes for corresponding electrodes in contact with tissue on opposite sides. Each of these electrodes is positioned in the distal portion of the end effector 100 defined by the ablation electrode length L2, such that they can be positioned to contact the tissue if desired by the physician 24. Figure 1 Preferably, the reference electrode 117 is positioned such that the physician 24 cannot, or is at least unlikely to, position the reference electrode 117 in contact with tissue, but remains relatively adjacent to the electrode configured to contact tissue. For example, the end effector 100 may be configured to flex such that when the distal portion of the first side 101a contacts tissue, the majority of the proximal portion is not in contact with tissue. By being positioned in the proximal portion, the reference electrode 117 therefore cannot, or is unlikely to, contact tissue during the procedure. In other words, the end effector is configured to flex such that the majority of the first side 101a of the distal portion is configured to conform to the planar surface when the reference electrode is separated from the planar surface. In such embodiments, the illustrated reference electrode 117 is a dedicated reference electrode rather than a multi-purpose electrode.

[0066] In some embodiments, at least the ablation electrode, diagnostic electrode, and tissue contact electrode are flush with the planar body to provide the end effector 100 with a first planar surface corresponding to a first side 101a of the planar body 140, and a second planar surface corresponding to a second side 101b of the planar body. Any combination of ablation electrodes 111, 112 and other electrodes 113, 114, 115, 116, 117 may include an exposed conductive layer in a flexible printed circuit board, which may include silver epoxy resin or conductive ink.

[0067] The planar body 140 shown includes openings 102, 105 located between a first side 101a and a second side 101b. The size and shape of the openings 102, 105 may be set or otherwise configured to allow an end effector to flex through a sheath conduit. This opening configuration may be determined by the size of the sheath conduit through which the end effector is configured for delivery. The size and shape of the openings 102, 105 may be set or otherwise configured to collapse or expand when the end effector presses against a nonplanar tissue surface to provide conformal contact with the nonplanar tissue surface. The applicant recognizes that consistent contact between the ablation electrode and nonplanar tissue can produce improved ablation foci compared to less conformal electrode contact. In some embodiments, the distal end may not be fully closed to allow for greater flexibility and a larger area. In some embodiments, the EM circuit extends through a paddle ridge between the openings. An external opening 102 is disposed between the elongated ablation electrode segments 111a, 111b, 112a, and 112b of the corresponding ablation electrodes 111 and 112. An internal opening 105 is disposed between the internal elongated ablation electrode segments 111b and 112b and the central portion 104.

[0068] Figure 3 Is it like this? Figure 2 An illustration of an enlarged view of a portion of the indicated example end effector 100. The planar body 140 includes a frame 150 surrounded by a flexible electrically insulating package 142. The insulating package may be primarily made of a polymer material, or may include components with higher insulation, as per [reference to...]. Figures 9A to 9D More specifically, the frame 150 is elastic and provides structural support for the end effector 100, allowing the end effector to retract into a delivery configuration for delivery through the sheath, then self-expand to an unconstrained planar configuration as shown, flexing to allow the distal portion to conform to a planar or near-planar surface (such as tissue), and collapsing upon retraction into the sheath. The frame 150 may be formed of a hyperelastic material or shape memory alloy, such as nickel-titanium (also known as nitinol), cobalt-chromium, stainless steel, or other alloys exhibiting pseudoelastic or hyperelastic properties.

[0069] The planar body 140 is divided into three sections: an outer section including an outer elongated ablation electrode section 111a, an inner section including an inner elongated ablation electrode section 111b, and a central portion 104. The planar body 140 includes... Figure 2 Shown but not in Figure 3The second outer segment and the second inner segment, located on the right side of the planar body, are shown, giving the planar body 140 a total of five segments. The outer segment has a width W4; the inner segment has a width W3; and the central portion 104 has a width W2. In the example shown, the body segment widths W2, W3, and W4 are approximately equal to each other. Each elongated ablation electrode segment 111a, 111b has a width W5 that exceeds half the width of the outer body segment W4 and the inner body segment W3, approximately 80%. The ablation electrode segment width W5 is approximately 10% of the total width W1 of the end effector 100.

[0070] Elongated ablation electrode segments 111a and 111b are positioned to the left or right of each other. Each of the elongated ablation electrode segments 111a and 111b extends distally to approximately the distal edge of the planar body 140. Because the distal edge is curved, the inner ablation electrode segment 111b defines a length L2 of the distal portion, while the length L5 of the outer ablation electrode segment 111a is shorter than the length L2 of the inner ablation electrode segment 111b.

[0071] The diagnostic electrode 113 shown is positioned on the outer segment of the planar body 140 and is entirely within the width W5 and length L5 of the longitudinally extending ablation electrode segment 111a. The diagnostic electrode 113 has a width W7 that is less than half, preferably about one-third, of the width W5 of the longitudinally extending ablation electrode segment 111a. The diagnostic electrode 113 has a length L4 that is less than half, less than or about one-fifth, or less than or about one-tenth of the length L5 of the longitudinally extending ablation electrode segment 111a.

[0072] Each elongated ablation electrode segment 111a, 111b has a serpentine shape. The serpentine shape of the outer longitudinally extending ablation electrode segment 111a bends around three of the four sides of the diagnostic electrode 113. As shown, the serpentine shape has a path width W6, which is approximately equal to the width W7 of the diagnostic electrode W7 and approximately one-third of the width W5 of the outer longitudinally extending ablation electrode segment 111a.

[0073] The end effector 100 also includes electrical traces 118 and 119, which have insulated serpentine electrical conductor portions. The illustrated electrical traces 118 and 119 extend longitudinally, forming a serpentine path within the central portion 104. The illustrated electrical traces 118 and 119 are electrically connected to the central tissue contact mass electrode pair 116 and the distal tissue contact mass electrode pair 115.

[0074] Figure 4This is an illustration of a first alternative electrode configuration for an example end effector 100, which includes an ablation electrode 111 and a diagnostic electrode 113. Similar to... Figure 2 and Figure 3 The ablation electrode 111 includes a serpentine longitudinally extending segment with a total width W5 and a path width W6. Although Figure 2 and Figure 3 The configuration includes only a single diagnostic electrode 113 for each ablation electrode 111, but Figure 4 The example includes six diagnostic electrodes 113 for each ablation electrode 111. The end effector 100 may include one, two, three, four, five, or six diagnostic electrodes 113 for each ablation electrode 111. The dimensions of each diagnostic electrode are set to be similar to the width W7, which is approximately 1.5 times the path width W6 of the ablation electrode 111 and approximately half the total width W5 of the elongated segments of the ablation electrode 111. The diagnostic electrodes 113 are surrounded on two or three sides by corresponding elongated segments of the ablation electrode 111.

[0075] Figure 5 This is an illustration of a second alternative electrode configuration for an example end effector. The configuration includes an ablation electrode 111 and a diagnostic electrode 113. The ablation electrode has elongated segments, each segment being divided into parallel strips. The diagnostic electrode is positioned adjacent to the elongated ablation electrode segments. Each elongated segment has multiple conductive strips extending parallel to each other to form a configuration similar to... Figure 4 The overall shape of the corresponding elongated segments is shown. Other ablation electrode shapes shown herein, and their alternative forms understood by those skilled in the art, can also be divided into similar forms. Figure 5 The diagram shows multiple conductive strips extending parallel to each other. This configuration increases the total edge length of the ablation electrode to provide tissue with an ablation electrode of a similar shape to that of a solid ablation electrode during PFA (e.g., as shown in the diagram). Figure 4 (As shown) different electric field distributions.

[0076] Figure 6 This is an illustration of a third example electrode configuration for an example end effector, which includes a rectangular elongated segment of ablation electrode 111 without a diagnostic electrode 113. The entire width W5 of the electrode segment is used for ablation electrode 111 to maximize the surface area of ​​ablation electrode 111. The diagnostic electrode may be disposed elsewhere on the planar body, such as in the central portion 104.

[0077] Figure 7 This is an illustration of a fourth example electrode configuration for an example end effector, which includes a rectangular elongated segment of an ablation electrode 111 interrupted by a diagnostic electrode 113. Figure 6Compared to the continuous rectangular electrode segments shown, the segmented, elongated ablation electrode segments can have greater flexibility to allow the planar body 140 to flex away from the longitudinal axis AA, but at the cost of the total ablation electrode area.

[0078] Figure 8 This illustration shows an example electrode configuration on one side of an example end effector. The example electrode configuration includes elongated ablation electrodes 111, 112 located in two ablation electrode regions 121, 122; diagnostic electrodes 113, 114 located in the two ablation electrode regions 121, 122; tissue contact electrodes 115, 116 located between the two ablation electrode regions 121, 122; and a reference electrode 117 located in the proximal region of the illustrated side of the end effector. In some embodiments, the total area of ​​each ablation electrode 111, 112 within the respective electrode regions 121, 122 is approximately 7.5 mm². 2 .exist Figure 8 As can be seen, there are two separate ablation electrodes 111a and 111b on the left side and two separate ablation electrodes 112a and 112b on the right side. The left electrodes 111a and 111b can be connected to a pulse field generator to deliver a biphasic pulse field between electrodes 111a and 111b. The right electrodes 112a and 112b can also be connected to a pulse field generator to deliver a biphasic pulse field between electrodes 112a and 112b. Alternatively, each of the left electrodes 111a and 111b can be connected to the generator together with each of the right electrodes 112a and 112b to deliver a bipolar pulse between the left and right electrodes. For example, a bipolar electrode pair can be formed by one or more left electrodes 111a and 111b together with one or more right electrodes 112a and 112b.

[0079] exist Figure 8 A centerline CC is drawn, indicating the line of symmetry of the electrode configuration or planar body. As shown, the electrode configuration is symmetrical about the centerline CC. Preferably, at least the ablation electrodes 111 and 112 are symmetrical about each other with respect to the centerline CC. As shown, the planar body can also be a shape symmetrical about the centerline CC. In an alternative embodiment, the planar body may not be symmetrical about the centerline CC. As shown, the centerline CC extends along the longitudinal axis AA. In an alternative embodiment, the centerline CC may not extend along the longitudinal axis AA.

[0080] The planar body 140 has a left half to the left of the centerline CC and a right half to the right of the centerline CC on one side. A first ablation electrode 111 defines a first electrode region 121, which is entirely within the left half of the planar body 140. A second ablation electrode 112 defines a second electrode region 122, which is entirely within the right half of the planar body 140. Tissue contact electrodes 115 and 116 are arranged in pairs, each tissue contact electrode being disposed across the centerline CC on the shown side of the planar body 140. The distal tissue contact electrode pair 115 is located near the distal end 106 of the planar body 140. The central tissue contact electrode pair 116 is located proximally relative to the distal pair 115 and is disposed across the centerline CC. A reference electrode 117 is disposed on the shown side of the planar body 140 and is disposed across the centerline CC.

[0081] Figures 9A to 9D This is an illustration of an alternative configuration of the insulating material in the cross-section of the end effector. The second side 101b of the planar body 140 is indicated as opposite to the first side 101a. Ablation electrodes 131 and 132 are shown on the second side 101b, opposite to the ablation electrodes 111 and 112 on the first side. The opposing ablation electrodes 131 and 132 overlap with, preferably with a majority of, the ablation electrodes 111 and 112 on the first side 101a, and may be symmetrical with respect to the plane defined by the planar body 140 and the ablation electrodes 111 and 112 on the first side 101a. For illustrative purposes, the cross-section of the planar body 140 is simplified to omit the frame 150, electrical traces, and other such features. Ablation electrodes 111, 112, 131, 132 are shown protruding from the planar body 140, but may alternatively be recessed into the planar body 140 to provide a smooth planar surface on each respective side 101a, 101b. Ablation electrodes 111, 112, 131, 132 may have approximately equal surface areas to each other. Each segment 111a, 111b, 112a, 112b, 131a, 131b, 132a, 132b of the ablation electrode is shown as continuous across its width. Alternatively, some or all segments may include similar... Figure 5 The parallel strips shown create segmented cross-sectional profiles.

[0082] Figures 9A to 9D The various configurations shown provide different levels of electrical insulation between electrodes on opposite sides of the planar body. This electrical insulation can be tailored to guide electric field lines between the bipolar ablation electrode pairs on opposite sides of the planar body 140 during PFA application, thereby guiding electroporation of cells within the target tissue.

[0083] Figure 9A Configured to have an opening in the end effector, such as Figure 8 As shown. Figure 9B This includes the polymer body region that extends the width of the end effector. Essentially, Figure 2 and Figure 3 Some or all of the openings 102, 105 (and other unlabeled openings) of the example end effector 100 shown may include corresponding thinned polymer-filled regions without a frame or any circuitry. With this configuration, the planar body 140 may provide additional electrical insulation between electrodes on opposite sides of the planar body 140 (compared to openings 102, 105) while maintaining sufficient maneuvering flexibility for tissue positioning and transfer through the sheath. Figure 9C A planar high-dielectric layer 144 is included between each side and extends the width of the end effector. The dielectric layer 144 overlaps with and is parallel to each of the ablation electrodes 111, 112, 113, 114. The planar high-dielectric layer 144 may comprise a ceramic-doped polymer to provide additional electrical insulation between the electrodes on opposite sides of the planar body compared to a single polymer, while still providing sufficient flexibility. As shown, the planar high-dielectric layer 144 extends across a large portion of the entire width W1 of the planar body 140. The planar body 140 includes longitudinally elongated regions (e.g., corresponding to...). Figure 2 and Figure 3 The longitudinally elongated region (with openings 102 and 105) includes a planar high-dielectric layer 140, without a frame or circuitry. Figure 9D This includes high-dielectric tiles 145 located between each side 101a, 101b and configured to overlap to collapse the end effector 100 into the delivery sheath. The high-dielectric tiles 145 may include ceramic plates extending longitudinally through each segment of the body and overlapping between the segments, such that the overlap corresponds to... Figure 2 and Figure 3 The openings 102 and 105 are shown. The high-dielectric tile or longitudinally extending ceramic plate may be angled relative to the plane defined by the planar body 140, such that the tile / plate 145 is configured to overlap when the end effector retracts into the sheath—with a longitudinal side on the longitudinal side.

[0084] Figure 10 This is an illustration of an end effector where ablation electrodes are configured to provide 1,200V pulses between ablation electrode regions. In some embodiments, the end effector 100 is configured to provide PFA electrical pulses of approximately 600V to approximately 1,200V between pairs of ablation electrodes 111, 112, 131, 132. Figure 10As shown, the end effector 100 is configured to provide an electrical pulse with an amplitude of 1,200V between bipolar pairs, each bipolar pair comprising an ablation electrode (i.e., electrode 111) located on the upper left side of the planar body and in contact with tissue, and an electrode (i.e., electrode 132) located on the upper right side of the planar body and not in contact with tissue. Similarly, electrodes 112 and 131 are paired. The paired electrodes are located on opposite sides of the planar body 140 and do not overlap.

[0085] In some embodiments, cardiac electrical signals can be measured from one or more diagnostic electrodes positioned on the tissue-contact side of the planar body. In some embodiments, tissue contact can be measured from a pair of tissue-contact electrodes positioned on the tissue-contact side of the planar body. In some embodiments, reference electrical signals can be measured from a reference electrode positioned on the tissue-contact side of the planar body, wherein the reference electrode itself does not contact the tissue.

[0086] Figure 11 It is Figure 10 The illustration shows the process applied to the end effector 100 of a potato model 160. A PFA electrical signal applied to the ablation electrode generates an ablation foci 161 with a depth D1 of approximately 7.5 mm. To generate the ablation foci, a first bipolar PFA electrical signal is applied to a first ablation electrode and a second ablation electrode, the first ablation electrode being disposed on a first side of the planar body of the planar end effector, and the second ablation electrode being disposed on a second side of the planar body and not overlapping with the first ablation electrode (i.e., ablation electrode pairs 111, 132). The first bipolar PFA electrical signal comprises 60 pulses having a magnitude of approximately 1,200 V and a total duration of approximately 4 seconds. A second bipolar PFA electrical signal is applied between a third and a fourth ablation electrode, the third ablation electrode being disposed on a first side of the planar body of the planar end effector and overlapping with the second ablation electrode, and the fourth ablation electrode being disposed on a second side of the planar body and overlapping with the second ablation electrode (i.e., ablation electrode pairs 112, 131). The second bipolar PFA electrical signal consists of 60 pulses, with a magnitude of approximately 1,200V and a total duration of approximately 4 seconds. The bipolar pulses may include an inter-pulse delay of approximately 2 microseconds.

[0087] Figure 12A , Figure 12B , Figure 12C , Figure 13 , Figure 14 , Figure 15A and Figure 15B An embodiment in which the end effector 100 includes a total of four ablation electrodes 111, 112, 131, 132 is shown, illustrating an ablation electrode pairing configuration for applying bipolar PFA electrical pulses with a voltage of about 600V to about 1,200V. (See also: Regarding...) Figure 10 In more detail, the end effector 100 preferably includes a total of two to eight ablation electrodes. The pattern of ablation electrode pairing can be adjusted based on the total number of ablation electrodes in the end effector 100, as per [reference to...]. Figure 10 This will be discussed in more detail, and as those skilled in the art will understand as inspired by the contents of this document.

[0088] Figure 12A and Figure 12B It shows the relationship with, as about Figure 10 and Figure 11 The ablation electrodes are paired across the body. The ablation electrodes in the ablation electrode pair are symmetrical with respect to the centerline CC and are located on opposite sides of the planar body 140. A voltage is applied across the electrodes in the paired electrode regions, wherein for each pair of electrode regions, the ablation electrode in the first electrode region is in contact with the tissue, and the other electrode region is located on the opposite side of the end effector and is opposite to the first electrode region across the centerline CC. Figure 12A and Figure 12B Two different pairs of electrode regions are shown. Figure 12A Elongated segments 111a, 111b of the ablation electrode 111 with positive charge are shown, while elongated segments 132a, 132b of the ablation electrode 132 have negative charge. This illustrates a positive voltage pulse configured to induce electroporation in tissue in contact with either side 101a, 101b of the planar body 140. Biphasic pulses can be applied, wherein the polarity is as follows: Figure 12A The polarity shown can be switched or alternated between the polarity where positive charges are on the ablation electrode 132 that is not in contact with tissue and negative charges are on the ablation electrode 111 that is in contact with tissue. This can be achieved as follows: Figure 12A The bipolar ablation electrode pair shown applies a bipolar pulse train (which may include biphasic pulses, monophasic pulses, or combinations thereof) between 111 and 132, and then... Figure 12B The bipolar ablation electrode shown applies a bipolar pulse train between 112 and 131.

[0089] Figure 12C Another configuration is shown in which ablation electrodes 131a and 131b are considered to be in contact with tissue. In this example, ablation electrodes 131a and 131b are no longer connected to each other, but are instead connected individually to the generator, allowing a biphasic pulsed field to be provided between the two tissue-contacting ablation electrodes in a bipolar configuration to allow electrons to flow between 131a and 131b. Similarly, ablation electrodes 131c and 131d (in contact with tissue) are no longer connected to each other, but are instead connected individually to the generator, allowing a biphasic pulsed field to be provided between the two tissue-contacting ablation electrodes to allow electrons to flow between them.

[0090] Figure 13An ablation electrode pairing configuration is shown, in which the ablation electrodes in the pair are symmetrical about the centerline CC and located on the same side of the planar body 140. As shown, electrodes 111 and 112, which are in contact with tissue, are applied across the tissue-contacting side 101a of the planar body 140. Electrodes 131 and 132, which are not in contact with tissue, can be used as reference electrodes. Biphasic pulses can be applied, wherein the polarity is as follows: Figure 13 The polarity shown can be switched or alternated between the polarity where positive charge is on the right ablation electrode 112 and negative charge is on the left ablation electrode 111. A bipolar pulse train can be applied between the bipolar ablation electrode pairs 111 and 112.

[0091] Figure 14 An ablation electrode pairing configuration is shown, in which the ablation electrodes in the pair overlap and are located on opposite sides of a planar body. A voltage is applied across the tissue-contacting ablation electrodes 111, 112 to the opposite sides of the planar body 140 and not in contact with tissue, to the non-tissue-contacting ablation electrodes 131, 132. Biphasic pulses can be applied, wherein the polarity is as follows: Figure 14 The polarity shown switches or alternates between the polarity of the ablation electrodes 131 and 132 that are not in contact with tissue and the polarity of the ablation electrodes 111 and 112 that are in contact with tissue. A bipolar pulse train can be applied between the bipolar ablation electrode pairs. As shown, the two electrodes 111 and 112 in contact with tissue are activated simultaneously. Alternatively, a bipolar pulse train can be applied to the first pair of ablation electrodes while de-energizing the second pair of ablation electrodes, and subsequently, a bipolar pulse train can be applied to the second pair of ablation electrodes while de-energizing the first pair of ablation electrodes.

[0092] Figure 15A and Figure 15B The diagram illustrates a voltage applied across an electrode pair, where the electrodes in the pair are positioned across a central axis. These electrode pairs are asymmetrical relative to the centerline, such that one electrode (or group of electrodes) in the pair is closer to the centerline than the other. In this configuration, electrode segments on opposite sides of the end effector body are activated as a unit and electrically coupled within a conduit. For example, electrodes 111a and 131a can form a bipolar pair with electrodes 112b and 132b, as shown. Figure 15A As shown. Similarly, as Figure 15B As shown, electrodes 111b and 131b can form a bipolar pair with electrodes 112a and 132a. Alternatively, only the electrodes on the tissue-contacting side of the planar body can be activated. For example, ablation electrodes 111a and 112b can form... Figure 15A The bipolar pair in the middle, while the opposing ablation electrodes 131a and 132b are disconnected. Similarly, in Figure 15B In the process, ablation electrodes 111b and 112a can form Figure 15AThe bipolar electrodes are connected in a bipolar pair, while the opposing ablation electrodes 131b and 132a are disconnected. A bipolar pulse train (which may include biphasic pulses, monophasic pulses, or combinations thereof) can be applied between the bipolar ablation electrode pairs, such as... Figure 15A As shown, and subsequently as Figure 15B As shown, in Figure 15A and Figure 15B It switches back and forth between the bipolar configurations.

[0093] Figure 16 This is an illustration of an example electrode configuration on one side of an example end effector, which includes elongated ablation electrodes 171, 172, 173, 174 located in four ablation electrode regions 181, 182, 183, 184; diagnostic electrodes 113, 114 located in at least two ablation electrode regions 181, 182; tissue contact electrodes 115, 116 located along the centerline CC between the ablation electrode regions; and a reference electrode 117 located in the proximal region of the illustrated side of the end effector 100. While the embodiment of the end effector 100 described above includes exactly four ablation electrodes 111, 112, 131, 132, the embodiment shown in FIG. 15 includes up to eight ablation electrodes, including those ablation electrodes 171, 172, 173, 174 shown and corresponding overlapping ablation electrodes (not shown) located on opposite sides of the planar body.

[0094] The end effector 100 preferably includes a total of two to eight ablation electrodes. The end effector 100 preferably includes exactly two, three, or four ablation electrodes on each side of the planar body 140. Each ablation electrode preferably overlaps with a corresponding ablation electrode on the opposite side of the planar body, such that the ablation electrodes are symmetrical with respect to the plane defined by the planar body 140. Fewer ablation electrodes can be achieved by electrically connecting combinations of ablation electrodes within the end effector 100 or elsewhere within the conduit 14. Increasing the number of ablation electrodes can be achieved by dividing the ablation electrodes into two parts, which are electrically insulated from each other within the conduit 14 and configured to be activated independently by the generator 50. Figure 15 shows an example where, as Figure 8 The ablation electrode 111 to the left of the center line CC shown is divided into two electrodes: the upper left ablation electrode 171 and the lower left ablation electrode 173. Similarly, as... Figure 8 The ablation electrode 112 to the right of the center line CC shown is divided into two electrodes: the upper right ablation electrode 172 and the lower right ablation electrode 174. Preferably, all ablation electrodes 171, 172, 173, and 174 have approximately the same surface area.

[0095] Figure 17This is an illustration of an example electrode configuration for an example end effector, which includes an elongated, serpentine ablation electrode. The elongated segment is serpentine, similar to... Figure 3 As shown. In one embodiment, the trace width W6 is approximately 0.28 mm, the electrode segment width W5 is approximately 1 mm, the ablation electrode surface area is approximately 10.1 square millimeters, the perimeter is approximately 67.7 mm, and the perimeter to area ratio is approximately 7:1.

[0096] Figure 18 This is an illustration of an example electrode configuration for an example end effector, which includes a rectangular, elongated ablation electrode. The elongated segment is solid, similar to... Figure 6 As shown, this means that the trace width is equal to the total width. In one embodiment, the electrode segment width W5 is approximately 1 mm, the ablation electrode surface area is approximately 16.8 square millimeters, the perimeter is approximately 37.4 mm, and the perimeter to area ratio is approximately 2:1.

[0097] Figure 19 This is an illustration of an example electrode configuration for an example end effector, which includes a large-area ablation electrode. In one embodiment, the electrode segment width W5 is approximately 3.5 mm, the ablation electrode surface area is approximately 28.8 square millimeters, the perimeter is approximately 24.8 mm, and the perimeter-to-area ratio is approximately 1:1.

[0098] Figure 20 This is an illustration of an example electrode configuration for an example end effector, in which the ablation electrode is wrapped around a ridge or insulating material surrounding the catheter body.

[0099] Figure 21 This is an illustration of an example electrode configuration for an example end effector, wherein the ablation electrode is partially wrapped around a ridge or insulating material surrounding the catheter body.

[0100] Figure 20 and Figure 21 Each electrode in the structure can be individually activated to form a bipolar pair that is symmetrical or asymmetrical with respect to the center line CC.

[0101] Ablation electrodes can be paired in various combinations to provide a bipolar PFA electrical signal between the ablation electrodes in a pair. Table 1 includes an overview of selected example ablation electrode pairs based on the examples shown herein. As will be understood by those skilled in the art inspired by the disclosure herein, the individual pairs can be activated simultaneously or sequentially in various combinations to achieve PFA in the target tissue.

[0102] Table 1: Overview of Selected Example Ablation Electrode Pairs

[0103]

[0104] In another alternative implementation (not shown), Figure 8 The segments 111a and 111b of the left-side ablation electrode 111 shown are electrically insulated from each other to form individual ablation electrodes. In an embodiment where all elongated ablation electrode segments form individual electrodes, the end effector 100 includes a total of eight elongated ablation electrodes. The exemplary ablation electrode configurations shown and described herein are non-limiting, and many other ablation electrode configurations are possible. In each ablation electrode configuration, the ablation electrodes can be paired according to the same concept outlined in Table 1.

[0105] The following provisions set forth non-restrictive embodiments of this disclosure:

[0106] Clause 1. An end effector for a medical probe, the end effector comprising: a planar body including a first side and a second side opposite to the first side and extending along a longitudinal axis; and a plurality of ablation electrodes, including a first ablation electrode and a second ablation electrode, the first ablation electrode being disposed on the first side of the planar body, the end effector being configured to provide a bipolar pulsed field ablation electrical signal between the first ablation electrode and the second ablation electrode, the first ablation electrode and the second ablation electrode each having a corresponding length of at least half of the total length of the end effector, the total length being measured from a distal end of the end effector to a distal end of the axis of the medical probe, such that the corresponding lengths of the first ablation electrode and the second ablation electrode define a distal portion of the end effector.

[0107] Clause 2. The end effector according to Clause 1 further includes: at least one diagnostic electrode disposed on at least one of the first side or the second side of the planar body, the at least one diagnostic electrode being electrically isolated from the plurality of ablation electrodes and configured to receive electrical signals from tissue.

[0108] Clause 3. The end effector according to Clause 2, wherein the at least one diagnostic electrode comprises a plurality of pairs of diagnostic electrodes, wherein each pair of diagnostic electrodes is disposed on a respective first side and a second side along an axis orthogonal to the longitudinal axis and opposite to each other.

[0109] Clause 4. The end effector according to any one of Clauses 1 to 3 further comprises: a pair of tissue contact electrodes disposed on the first side of the planar body.

[0110] Clause 5. The end effector according to any one of Clauses 1 to 4 further comprises: a plurality of pairs of tissue contact electrodes spaced apart along the longitudinal axis, each of the plurality of pairs of tissue contact electrodes being disposed on at least one of the first side or the second side, near the distal portion of the end effector.

[0111] Clause 6. The end effector according to any one of Clauses 1 to 4, wherein the plurality of first ablation electrodes comprises four individual first ablation electrodes, wherein each of the four first ablation electrodes is connectable to the other three ablation electrodes to form one or more combinations of first ablation electrodes with an electrode area larger than any individual first ablation electrode, and the plurality of second ablation electrodes comprises four individual second ablation electrodes, wherein each of the four second ablation electrodes is connectable to any of the other three second ablation electrodes to form a combination of second ablation electrodes with an electrode area larger than any individual second ablation electrode.

[0112] Clause 7. An end effector according to any one of Clauses 1 to 6, said end effector comprising a proximal portion located on the proximal side of the distal portion and without any ablation electrode.

[0113] Clause 8. The end effector according to Clause 7, wherein any two of the individual first ablation electrodes are configured to be electrically connected to a biphasic pulse field generator, and any two of the individual second ablation electrodes are electrically connected to a biphasic pulse field generator, the end effector further comprising: a reference electrode disposed on the first side of the planar body and in the proximal portion.

[0114] Clause 9. The end effector according to Clause 8, wherein the end effector is configured to flex such that a majority of the first side of the distal portion is configured to conform to the planar surface when the reference electrode is separated from the planar surface.

[0115] Clause 10. The end effector according to any one of Clauses 1 to 9, wherein the first ablation electrode and the second ablation electrode each extend substantially to the distal end of the end effector.

[0116] Clause 11. An end effector according to any one of Clauses 1 to 10, wherein the planar body includes a central portion extending along the longitudinal axis and centrally extending along the total length of the end effector, the total length being measured from the distal end of the end effector to the distal end of the axis of the medical probe, the central portion having no ablation electrodes.

[0117] Clause 12. The end effector according to any one of Clauses 1 to 11, wherein the first ablation electrode comprises a plurality of longitudinally elongated segments positioned to the left or right of each other.

[0118] Clause 13. The end effector according to Clause 12, each of the plurality of longitudinally extending segments defines a width, wherein the diagnostic electrode is fully positioned within the width of the corresponding longitudinally extending segment of the first ablation electrode.

[0119] Clause 14. The end effector according to Clause 13, wherein the diagnostic electrode has a width less than half the width of the corresponding longitudinal extension segment.

[0120] Clause 15. The end effector according to Clause 14, wherein the width of the diagnostic electrode is approximately one-third of the width of the corresponding longitudinal extension segment.

[0121] Clause 16. The end effector according to any one of Clauses 12 to 15, wherein the diagnostic electrode is fully positioned within the length of the corresponding longitudinal extension segment of the first ablation electrode.

[0122] Clause 17. The end effector according to Clause 16, wherein the diagnostic electrode has a length less than half the length of the corresponding longitudinal extension segment.

[0123] Clause 18. The end effector according to Clause 17, wherein the diagnostic electrode has a length less than one-fifth of the length of the corresponding longitudinal extension segment.

[0124] Clause 19. The end effector according to Clause 18, wherein the diagnostic electrode has a length less than one-tenth the length of the corresponding longitudinal extension segment.

[0125] 20. The end effector according to any one of clauses 1 to 19, wherein each of the plurality of ablation electrodes comprises a serpentine shape.

[0126] Clause 21. The end effector according to Clause 20, wherein the serpentine shape of the first ablation electrode bends around at least three of the four sides of the diagnostic electrode.

[0127] Clause 22. The end effector according to any one of Clauses 1 to 21, wherein each of the plurality of elongated segments comprises a plurality of conductive strips extending parallel to each other to form the overall shape of the respective elongated segment of the plurality of elongated segments.

[0128] Clause 23. The end effector according to any one of Clauses 1 to 22 further comprises: an electrical trace, the electrical trace comprising an insulated serpentine electrical conductor portion.

[0129] Clause 24. The end effector according to any one of Clauses 1 to 23, wherein the total surface area of ​​the first ablation electrode is approximately 7.5 mm². 2 .

[0130] 25. The end effector according to any one of clauses 1 to 24, wherein each of the plurality of ablation electrodes is flush with the planar body to provide the end effector with a first planar surface corresponding to the first side of the planar body and to provide the end effector with a second planar surface corresponding to the second side of the planar body.

[0131] Clause 26. The end effector according to any one of Clauses 1 to 25 further comprises: an inductive loop navigation sensor disposed in the planar body.

[0132] Clause 27. The end effector according to any one of Clauses 1 to 26, wherein the plurality of ablation electrodes comprise silver epoxy resin.

[0133] Clause 28. The end effector according to any one of Clauses 1 to 27, wherein the plurality of ablation electrodes comprise conductive ink.

[0134] Clause 29. The end effector according to any one of Clauses 1 to 28, wherein the planar body is symmetrical about a centerline that bisects the planar body along the longitudinal axis.

[0135] Clause 30. The end effector according to Clause 29, when viewed from the first side, the planar body has a left half and a right half, the left half being to the left of the centerline and the right half being to the right of the centerline, and the first ablation electrode defining a first electrode region entirely disposed in the left half.

[0136] Clause 31. The end effector according to Clause 30 further includes: a pair of tissue contact electrodes disposed across the centerline on the first side of the planar body.

[0137] Clause 32. The end effector according to Clause 30 or 31, wherein the pair of tissue contact electrodes are located near the distal end of the end effector.

[0138] Clause 33. The end effector according to Clause 32 further includes: a second pair of tissue contact electrodes disposed on the first side in a proximal direction relative to the pair of tissue contact electrodes and across the centerline.

[0139] Clause 34. The end effector according to any one of Clauses 30 to 33 further includes: a reference electrode disposed across the centerline on the first side of the planar body.

[0140] Clause 35. The end effector according to any one of Clauses 30 to 34, wherein the plurality of ablation electrodes further comprises a third ablation electrode and a fourth ablation electrode, the end effector being configured to provide a bipolar pulsed field ablation electrical signal between the third ablation electrode and the fourth ablation electrode.

[0141] Clause 36. The end effector according to Clause 35, wherein the first ablation electrode, the second ablation electrode, the third ablation electrode and the fourth ablation electrode have substantially equal surface areas to each other.

[0142] Clause 37. In the end effector according to Clause 35 or 36, each of the first ablation electrode, the second ablation electrode, the third ablation electrode, and the fourth ablation electrode defines a corresponding electrode region, each electrode region in the corresponding electrode region being initially located entirely in the right half of the planar body or entirely in the left half of the planar body.

[0143] Clause 38. The end effector according to any one of Clauses 1 to 37, wherein the planar body includes an opening passing through it between the first side and the second side (101b).

[0144] Clause 39. The end effector according to any one of Clauses 1 to 38, wherein the planar body comprises a polymer encapsulation.

[0145] Clause 40. The end effector according to any one of Clauses 1 to 39, wherein the planar body comprises a plurality of elongated, thinned polymer-filled regions, the plurality of elongated, thinned polymer-filled regions being without a frame and without circuitry.

[0146] Clause 41. The end effector according to any one of Clauses 1 to 40, wherein the planar body includes a planar high-dielectric layer that overlaps with and is parallel to each of the plurality of ablation electrodes.

[0147] Clause 42. The end effector according to Clause 41, wherein the planar high-dielectric layer comprises a ceramic-doped polymer.

[0148] Clause 43. An end effector as described in Clause 41 or 42, wherein the planar high-dielectric layer extends across most of the entire width of the planar body.

[0149] Clause 44. The end effector according to any one of Clauses 41 to 43, wherein the planar body includes a longitudinally elongated region, the longitudinally elongated region including the planar high-dielectric layer, without a frame and without circuitry.

[0150] Clause 45. The end effector according to any one of Clauses 1 to 44, wherein the planar body comprises at least one ceramic plate.

[0151] Clause 46. The end effector according to Clause 45, wherein the at least one ceramic plate comprises a plurality of longitudinally extending ceramic plates.

[0152] Clause 47. The end effector according to Clause 46, wherein the plurality of longitudinally extending ceramic plates are angled such that the plurality of longitudinally extending ceramic plates are configured to overlap on the longitudinal side when the end effector is retracted into the sheath.

[0153] Clause 48. An end effector according to any one of Clauses 1 to 47, wherein the end effector is configured to provide a pulsed field ablation pulse with a voltage of about 600 volts to about 1,200 volts between pairs of ablation electrodes in the plurality of ablation electrodes.

[0154] Clause 49. The end effector according to any one of Clauses 1 to 48, said end effector being configured to provide an ablation foci depth of approximately 7.5 mm in a potato model.

[0155] Clause 50. The end effector according to any one of Clauses 1 to 49, wherein the second ablation electrode is disposed on the second side of the planar body and does not overlap with the first ablation electrode.

[0156] Clause 51. The end effector according to any one of Clauses 1 to 49, wherein the second ablation electrode is disposed on the first side of the planar body and does not overlap with the first ablation electrode.

[0157] Clause 52. The end effector according to Clause 50 or 51, when viewed from the first side, the planar body has a left half and a right half, the left half being to the left of a center line that bisects the planar body along the longitudinal axis, the right half being to the right of the center line, the first ablation electrode defining a first electrode region entirely disposed in the left half, and the second ablation electrode defining a second electrode region entirely disposed in the right half.

[0158] Clause 53. The end effector according to any one of Clauses 1 to 49, wherein the second ablation electrode is disposed on the second side of the planar body, substantially overlapping the first ablation electrode.

[0159] Clause 54. The end effector according to any one of Clauses 1 to 53, wherein the plurality of ablation electrodes comprises exactly two, three, or four ablation electrodes on the first side of the planar body and exactly two, three, or four ablation electrodes on the second side of the planar body.

[0160] Clause 55. The end effector according to Clause 54, wherein the plurality of ablation electrodes comprises exactly two ablation electrodes on the first side of the planar body and exactly two ablation electrodes on the second side of the planar body.

[0161] Clause 56. The end effector according to Clause 54, wherein the plurality of ablation electrodes comprises exactly four ablation electrodes on the first side of the planar body and exactly four ablation electrodes on the second side of the planar body.

[0162] Clause 57. The end effector according to any one of Clauses 54 to 56, wherein the plurality of ablation electrodes located on the first side of the planar body exactly overlap with the plurality of ablation electrodes located on the second side of the planar body.

[0163] Clause 58. A method for providing a pulsed field ablation signal to a planar end effector, the method comprising: providing a first bipolar pulsed field ablation signal between a first ablation electrode and a second ablation electrode, the first ablation electrode being disposed on a first side of a planar body of the planar end effector, and the second ablation electrode being disposed on a second side of the planar body and not overlapping with the first ablation electrode; and using the planar end effector to generate an ablation foci with a depth of approximately 7.5 mm in a potato model.

[0164] Clause 59. The method according to Clause 58, wherein providing the first bipolar pulse field ablation electrical signal comprises: providing a pulse of approximately 1,200 volts for a duration of approximately 4 seconds.

[0165] Clause 60. The method according to Clause 58 or 59, wherein providing the first bipolar pulse field ablation electrical signal comprises providing 60 electrical pulse bursts.

[0166] Clause 61. The method according to any one of Clauses 58 to 60 further comprises: providing a second bipolar pulsed field ablation signal between a third ablation electrode and a fourth ablation electrode, the third ablation electrode being disposed on a first side of the planar body of the planar end effector and overlapping with the second ablation electrode, and the fourth ablation electrode being disposed on a second side of the planar body and overlapping with the second ablation electrode.

[0167] Clause 62. The method according to any one of Clauses 58 to 61 further includes: measuring cardiac electrical signals from diagnostic electrodes disposed on the first side of the planar body.

[0168] Clause 63. The method according to any one of Clauses 58 to 62 further comprises: measuring tissue contact from a pair of tissue contact electrodes disposed on the first side of the planar body.

[0169] Clause 64. The method according to any one of Clauses 58 to 63, wherein the bipolar pulse includes an inter-pulse delay of approximately 2 microseconds.

[0170] Exemplary embodiments of the subject matter contained herein have been shown and described, and further improvements to the methods and systems described herein can be achieved through appropriate modifications without departing from the scope of the claims. For example, the end effector 100 may have an alternative shape or include alternative materials, and the electrical signals used to implement the PFA may be modified to suit the specific geometry and material of the end effector 100. Furthermore, where the methods and steps described above represent specific events occurring in a particular order, it is intended herein that certain specific steps need not necessarily be performed in the described order, but may be performed in any order, as long as the steps enable the embodiment to achieve its intended purpose. Therefore, if variations of the invention exist and these variations fall within the substantial scope of the disclosure or equivalents of the invention found in the claims, this patent is intended to cover such variations as well. Many such modifications will be apparent to those skilled in the art. For example, the examples, embodiments, geometries, materials, dimensions, ratios, steps, etc., described above are illustrative. Therefore, the claims should not be limited to the specific details of the structures and operations shown in this written description and the drawings.

Claims

1. An end effector for a medical probe, the end effector comprising: A planar body, the planar body including a first side and a second side opposite to the first side, and extending along a longitudinal axis; and Multiple ablation electrodes are provided, including a first ablation electrode and a second ablation electrode, wherein the first ablation electrode is disposed on the first side of the planar body. The end effector is configured to provide a bipolar pulsed field ablation electrical signal between the first ablation electrode and the second ablation electrode. The first ablation electrode and the second ablation electrode each have a corresponding length that is at least half of the total length of the end effector, the total length being measured from the distal end of the end effector to the distal end of the axis of the medical probe, such that the corresponding lengths of the first ablation electrode and the second ablation electrode define the distal portion of the end effector.

2. The end effector according to claim 1, further comprising: At least one diagnostic electrode is disposed on at least one of the first side or the second side of the planar body, the at least one diagnostic electrode being electrically isolated from the plurality of ablation electrodes and configured to receive electrical signals from tissue.

3. The end effector according to claim 2, wherein the at least one diagnostic electrode comprises a plurality of pairs of diagnostic electrodes, wherein each pair of diagnostic electrodes is disposed on a respective first side and a second side opposite to each other along an axis orthogonal to the longitudinal axis.

4. The end effector according to claim 1, further comprising: Multiple pairs of tissue contact electrodes are spaced apart along the longitudinal axis, and each pair of tissue contact electrodes is disposed on at least one of the first side or the second side, near the distal portion of the end effector.

5. The end effector according to claim 1, comprising: A plurality of first ablation electrodes, the plurality of first ablation electrodes including four individual first ablation electrodes, the first ablation electrode being one of the four individual first ablation electrodes, wherein each of the four first ablation electrodes is capable of being connected to the other three ablation electrodes to form one or more combined first ablation electrodes with an electrode area larger than any individual first ablation electrode; and A plurality of second ablation electrodes, the plurality of second ablation electrodes including four separate second ablation electrodes, wherein each of the four separate second ablation electrodes is capable of being connected to any of the other three second ablation electrodes to form a combined second ablation electrode with an electrode area larger than any single second ablation electrode.

6. The end effector of claim 1, wherein the first ablation electrode comprises a plurality of longitudinally elongated segments positioned to the left or right of each other, each of the plurality of longitudinally elongated segments defining a width and a length, wherein the diagnostic electrode is fully positioned within the width of the respective longitudinally elongated segment of the first ablation electrode and fully positioned within the length of the respective longitudinally elongated segment of the first ablation electrode.

7. The end effector according to claim 1, wherein, Each of the plurality of ablation electrodes includes a serpentine shape, wherein the serpentine shape of the first ablation electrode bends around at least three of the four sides of the diagnostic electrode.

8. The end effector according to claim 1, wherein each of the plurality of ablation electrodes is flush with the planar body to provide the end effector with a first planar surface corresponding to the first side of the planar body, and to provide the end effector with a second planar surface corresponding to the second side of the planar body.

9. The end effector according to claim 1, The planar body is symmetrical about the center line that bisects the planar body along the longitudinal axis. When viewed from the first side, the planar main body has a left half and a right half. The left half is to the left of the center line. The right half is to the right of the center line, and The first ablation electrode defines a first electrode region that is completely disposed in the left half.

10. The end effector according to claim 9, further comprising: A pair of tissue contact electrodes, the pair of tissue contact electrodes being disposed across the centerline on the first side of the planar body; and A reference electrode is disposed on the first side of the planar body across the center line.

11. The end effector of claim 9, wherein the plurality of ablation electrodes further comprises a third ablation electrode and a fourth ablation electrode, and the end effector is configured to provide a bipolar pulsed field ablation electrical signal between the third ablation electrode and the fourth ablation electrode.

12. The end effector according to claim 11, wherein the first ablation electrode, the second ablation electrode, the third ablation electrode and the fourth ablation electrode have substantially equal surface areas to each other.

13. The end effector of claim 11, wherein each of the first ablation electrode, the second ablation electrode, the third ablation electrode, and the fourth ablation electrode defines a corresponding electrode region, each electrode region in the corresponding electrode region being initially located entirely in the right half of the planar body or entirely in the left half of the planar body.

14. The end effector of claim 1, wherein the planar body comprises a planar high-dielectric layer that overlaps with and is parallel to each of the plurality of ablation electrodes.

15. The end effector of claim 14, wherein the planar high-dielectric layer comprises a ceramic-doped polymer.

16. The end effector of claim 14, wherein the planar body includes a longitudinally elongated region, the longitudinally elongated region including the planar high-dielectric layer, without a frame and without circuitry.

17. The end effector of claim 1, wherein the planar body comprises a plurality of longitudinally extending ceramic plates angled such that the plurality of longitudinally extending ceramic plates are configured to overlap on the longitudinal side when the end effector retracts into the sheath.

18. The end effector of claim 1, wherein the end effector is configured to provide a pulsed field ablation pulse with a voltage of about 600 volts to about 1,200 volts between ablation electrode pairs of the plurality of ablation electrodes.

19. The end effector according to claim 1, The second ablation electrode is disposed on the second side of the planar body and does not overlap with the first ablation electrode. When viewed from the first side, the planar main body has a left half and a right half. The left half is located to the left of the center line that bisects the planar body along the longitudinal axis. The right half is to the right of the center line. The first ablation electrode defines a first electrode region that is completely disposed in the left half, and The second ablation electrode defines a second electrode region that is completely disposed in the right half.

20. The end effector of claim 1, wherein the plurality of ablation electrodes comprises exactly two, three, or four ablation electrodes on the first side of the planar body and exactly two, three, or four ablation electrodes on the second side of the planar body.

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