Method and apparatus for performing ablation of tissue

Abstract

An ablation device may include an end effector having a working surface; a connector configured to electrically couple the energy source to the end effector; and / or a plurality of electrodes on the working surface and configured to apply energy from an energy source to tissue. The plurality of electrodes may include a first electrode and a second electrode on opposite sides of one or more intermediate electrodes. The plurality of electrodes may be configured such that the first electrode delivers a first voltage and the second electrode delivers a second voltage, and the one or more intermediate electrodes each delivers an intermediate voltage. A voltage potential difference between the first voltage and the second voltage is greater than a voltage potential difference between the first electrode and an intermediate voltage of any one of the one or more intermediate electrodes.

Description

Cross - Reference to Related Applications

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 373,370, filed on August 24, 2022, entitled "METHODS AND APPARATUS FOR PERFORMING DEEP ABLATIONS FOR RADIOFREQUENCY ABLATION OF TISSUE", which is hereby incorporated by reference in its entirety. Technical Field

[0002] The present disclosure is directed to medical devices and related methods, and more particularly, to electrosurgical devices and methods, such as devices and related methods for ablating tissue. Background Art

[0003] The present disclosure contemplates that ablation (e.g., radiofrequency (RF) ablation) can be used as part of a surgical procedure to treat atrial fibrillation, irregular heart rate, and tachycardia. RF ablation heats cardiac tissue to form ablation lesions that disrupt abnormal electrical signals, which may be part of the process of restoring a normal heartbeat. Specific ablation patterns can redirect electrical signals into more appropriate patterns to help treat atrial fibrillation. RF ablation can be applied by clamping tissue via an RF clamp or by pressing and / or aspirating on the exterior of the tissue via an RF pen and / or aspirating device. RF ablation is typically performed at a total power output of 1V - 100V, 100kHz - 1000kHz, and 1 watt - 100 watts. The tissue thickness in critical areas of the heart can range from 2mm - 15mm. The tissue is preferably ablated to achieve transmurality, such that the ablation substantially extends through the thickness of the cardiac tissue muscle.

[0004] The present disclosure contemplates that tissue ablation can be achieved by heating the tissue to about 55°C to 60°C. However, various factors during ablation can typically cause the tissue to be heated beyond this range (e.g., to 100°C or higher). Overheating of the tissue can result in drawbacks such as surface damage and / or charred tissue (which can affect healing time) and steam pops (which can cause holes in the tissue). Additionally, some end effectors can reach high temperatures after one or more ablations because heat is generated at the tissue. This can cause portions of the end effector to be heated above 55°C, which can result in damage to areas in the body adjacent to the heart and in contact with the end effector.

[0005] Some strategies contemplated by the present disclosure for cooling cardiac tissue include adding a heat sink in the device end effector, including actively cooling a liquid, and reducing the electrical output of the device. However, these methods may have their own drawbacks. For example, the heat sink may become overheated after multiple ablations. Active cooling requires a liquid source external to the device, which increases the complexity of the device and requires more energy for ablation. Reducing the electrical output may result in a decrease in the efficiency of the procedure.

[0006] Accordingly, although known devices have been used safely and effectively, there remains a need for improved devices and methods that can improve electro-surgery of tissue (e.g., ablation) while limiting unnecessary damage to the ablated tissue or surrounding tissue. SUMMARY

[0007] Some aspects of the present disclosure are presented below to provide a basic understanding of the technologies discussed. This presentation is not an extensive overview of all contemplated features of the present disclosure, and is neither intended to identify the main or key elements of all aspects of the present disclosure, nor to delineate the scope of any or all aspects of the present disclosure. Its sole purpose is to present one or more aspects of the present disclosure in an introductory form as a prelude to the more detailed description that follows.

[0008] One aspect of the present disclosure is to provide an ablation device for use with an energy source to apply energy to tissue, the ablation device comprising: (a) an end effector having a working surface; (b) a connector configured to electrically couple the energy source to the end effector; and (c) a plurality of electrodes in electrical communication with the working surface and configured to apply energy from the energy source to the tissue, wherein the plurality of electrodes includes a first electrode and a second electrode on opposite sides of one or more intermediate electrodes, wherein, during energy application, the plurality of electrodes are configured such that the first electrode delivers a first voltage and the second electrode delivers a second voltage, wherein each of the one or more intermediate electrodes delivers an intermediate voltage, wherein the voltage potential difference between the first voltage and the second voltage is greater than the voltage potential difference between the first electrode and the intermediate voltage of any one of the one or more intermediate electrodes, such that the tissue is ablated while also limiting thermal variations within the tissue and locations at the tissue surface where the surface temperature exceeds a maximum temperature.

[0009] In a more detailed embodiment of the first aspect, the end effector includes a radiofrequency pen. In yet another more detailed embodiment, the end effector includes a radiofrequency clamp. In another detailed embodiment, the end effector includes a radiofrequency pen or radiofrequency pod that includes vacuum suction. In yet another detailed embodiment, the end effector includes an expandable device. In a more detailed embodiment, the expandable device includes an inflatable element. In a more detailed embodiment, the first and second electrodes have a greater width than the intermediate electrode. In another more detailed embodiment, the first and second electrodes have a width of 2 to 8 mm, the intermediate electrode has a width less than that of the first and second electrodes, and the total width including the maximum voltage potential difference is between 10 and 30 mm. In yet another more detailed embodiment, the lengths of the plurality of electrodes are configured to produce a desired ablation length. In yet another more detailed embodiment, the plurality of electrodes includes three or more electrodes.

[0010] In yet another more detailed embodiment of the first aspect, the plurality of electrodes are distributed in a rectangular array. In yet another more detailed embodiment, the first, second, and intermediate electrodes are distributed annularly, wherein each electrode is concentric with an adjacent electrode. In another detailed embodiment, the power of each electrode is different from that of an adjacent electrode. In yet another detailed embodiment, the current of each electrode is different from that of an adjacent electrode. In a more detailed embodiment, the intermediate electrode includes a resistive conductor, wherein the resistive conductor is configured to reduce the potential difference between the first and second electrodes. In a more detailed embodiment, the voltage potential difference between each adjacent electrode is uniform or non-uniform. In another more detailed embodiment, the maximum voltage potential difference is between 10 volts and 500 volts. In yet another more detailed embodiment, the maximum voltage potential difference is between 30 and 80 volts. In yet another more detailed embodiment, the total power output is between 1 watt and 200 watts.

[0011] In a more detailed embodiment of the first aspect, the total power output is between 10 watts and 40 watts. In yet another more detailed embodiment, the applied frequency is between 50 kilohertz and 5000 kilohertz. In another detailed embodiment, the applied frequency is between 300 and 500 kilohertz. In yet another detailed embodiment, a plurality of electrode arrays are located end-to-end on the tissue ablation device to extend the surface length of the ablation area while maintaining electrical and thermal energy within the width and depth of the ablation area. In a more detailed embodiment, the voltage and current of each electrode are in phase or out of phase with adjacent electrodes, where the phase is the time-dependent phase of the applied AC voltage potential. In a more detailed embodiment, the voltage and current of each of the first electrode and the second electrode are sinusoidal waves that vary with time. In another more detailed embodiment, the voltage and current of each of the first electrode and the second electrode are rectangular waves that vary with time. In yet another more detailed embodiment, the intermediate electrode is electrically disconnected from the first electrode and the second electrode, where the intermediate electrode conducts current and reduces the resistance between the first electrode and the second electrode.

[0012] A second aspect of the present disclosure is to provide a tissue ablation device for ablating tissue, the device comprising: (a) an end effector having a tissue contact surface; (b) a power source coupled to the end effector; and (c) an array of electrodes in electrical communication with the tissue contact surface, wherein each electrode in the array of electrodes is maintained at a voltage potential, current, or power provided from a voltage source, where the voltage potential, current, or power of each electrode is different from the voltage potential, current, or power of an adjacent electrode, and where the array of electrodes is configured to ablate tissue while distributing the potential across the surface of the tissue such that the distribution of the potential reduces temperature variations within the ablated tissue.

[0013] A third aspect of the present disclosure is to provide a method for ablating tissue, the method comprising: (a) positioning an end effector at a target site of the tissue, where the end effector includes a tissue contact surface in electrical communication with an array of electrodes; (b) applying a voltage potential, current, or power from a power source to each electrode in the array of electrodes, where the array of electrodes includes a distributed potential and is configured to ablate the tissue while distributing the potential across the tissue; and (c) ablating tissue spaced apart from the end effector while minimizing the heat applied to the surface of the tissue in order to produce a more uniform and deeper ablation.

[0014] A fourth aspect of the present disclosure is to provide an electrosurgical device comprising: (a) a first electrode; (b) a second electrode; and (c) an intermediate electrical element, where the first electrode, the second electrode, and the intermediate electrical element are configured to be in electrical communication with target tissue, and where the intermediate electrical element is interposed between the first electrode and the second electrode.

[0015] In a more detailed embodiment of the fourth aspect, the intermediate electrical element includes at least one intermediate electrode. In yet another more detailed embodiment, the at least one intermediate electrode includes a plurality of intermediate electrodes. In a further detailed embodiment, the at least one electrical parameter includes current. In yet another further detailed embodiment, the first electrode, the at least one intermediate electrode, and the second electrode are configured to deliver electrical energy to the target tissue, and at least one electrical parameter of the electrical energy varies incrementally among the first electrode, the at least one intermediate electrode, and the second electrode. In a more detailed embodiment, the at least one electrical parameter includes potential. In a more detailed embodiment, the at least one electrical parameter includes power.

[0016] A fifth aspect of the present disclosure is to provide an electrosurgical system, which includes: (a) an electrosurgical device, the electrosurgical device includes: (i) a first electrode; (ii) a second electrode; and (iii) an intermediate electrical element, wherein the first electrode, the second electrode, and the intermediate electrical element are configured to be in electrical communication with the target tissue, and wherein the intermediate electrical element is interposed between the first electrode and the second electrode; (b) a resistive voltage divider, the resistive voltage divider is electrically connected to a first input conductor and a second input conductor, the resistive voltage divider includes a first resistor and a second resistor, wherein the first resistor and the second resistor are electrically connected in series between the first input conductor and the second input conductor, and wherein the first electrode is configured to be electrically connected to a first input connector, the second electrode is configured to be electrically connected to a second input connector, and at least one intermediate electrode is configured to be electrically connected to at least one intermediate conductor, and the at least one intermediate conductor is electrically connected between the first resistor and the second resistor.

[0017] In a more detailed embodiment of the fifth aspect, the resistive voltage divider is disposed in at least one of a handle, a shaft, an end effector, or a connection element of the electrosurgical device, the first input conductor and the second input conductor are configured to be releasably electrically coupled to an electrosurgical generator, the first input conductor is electrically coupled to the first electrode, the second input conductor is electrically coupled to the second electrode, and the at least one intermediate electrode is electrically coupled to the at least one intermediate conductor. In yet another more detailed embodiment, the resistive voltage divider is disposed in an interface component, the interface component is configured to be electrically interposed between the electrosurgical device and the electrosurgical generator, the first input conductor and the second input conductor are configured to be releasably electrically coupled to the electrosurgical generator, the first input conductor is configured to be releasably electrically coupled to the first electrode, the second input conductor is configured to be releasably electrically coupled to the second electrode, and the at least one intermediate conductor is configured to be releasably electrically coupled to the at least one intermediate electrode. In a further detailed embodiment, the resistive voltage divider is disposed in the electrosurgical generator, the first input conductor is configured to be releasably electrically coupled to the first electrode, the second input conductor is configured to be releasably electrically coupled to the second electrode, and the at least one intermediate conductor is configured to be releasably electrically coupled to the at least one intermediate electrode.

[0018] A sixth aspect of the present disclosure is to provide an electrosurgical device, comprising: (a) a first electrode; (b) a second electrode; and (c) at least one intermediate resistive element, wherein the first electrode, the second electrode, and the at least one intermediate resistive element are configured to be in electrical communication with a target tissue, and wherein the at least one intermediate resistive element is interposed between the first electrode and the second electrode.

[0019] In a more detailed embodiment of the sixth aspect, the at least one intermediate resistive element includes a first resistive element electrically connected to the first electrode and a second resistive element electrically connected to the second electrode, and the first resistive element is not directly electrically connected to the second resistive element. In yet another more detailed embodiment, the first resistive element and the second resistive element are interposed by a gap therebetween. In a further detailed embodiment, the gap includes at least one of an unoccupied space and a non-conductive element. In still another detailed embodiment, the at least one intermediate resistive element is electrically connected between the first electrode and the second electrode. In a more detailed embodiment, the resistance of the at least one intermediate resistive element is approximately equal to the resistance of the target tissue.

[0020] A seventh aspect of the present disclosure is to provide an electrosurgical device, comprising: (a) a tissue contact surface that is in electrical communication with a first electrode, a second electrode, and a plurality of intermediate electrodes; and (b) an electrical input connector, wherein the first electrode and the second electrode are spaced apart by a first width, wherein the plurality of intermediate electrodes are sequentially disposed between the first electrode and the second electrode along the first width, and wherein at least one electrical parameter varies between the first electrode, the plurality of intermediate electrodes, and the second electrode such that the electrical parameter has a first value at the first electrode, a second value at the second electrode, and a corresponding intermediate value between the first value and the second value at each of the intermediate electrodes.

[0021] In yet another more detailed embodiment of the seventh aspect, the intermediate values vary incrementally between the first electrode, each intermediate electrode, and the second electrode.

[0022] An eighth aspect of the present disclosure is to provide an ablation device for forming an ablation lesion in a target tissue, the ablation device comprising: (a) an end effector that includes a tissue engagement portion configured to engage the target tissue, the tissue engagement portion being configured for electrical contact with the target tissue and including a first tissue contact portion, a second tissue contact portion, and an intermediate tissue contact portion, wherein the intermediate tissue contact portion is disposed between the first tissue contact portion and the second tissue contact portion, and wherein the first tissue contact portion, the intermediate tissue contact portion, and the second tissue contact portion are electrically coupled such that when the end effector is supplied with electroablation energy, the magnitude of at least one electrical parameter is different between the first tissue contact portion, the intermediate tissue contact portion, and the second tissue contact portion such that the magnitude of the intermediate tissue contact portion is between the magnitude of the first tissue contact portion and the magnitude of the second tissue contact portion.

[0023] In yet another more detailed embodiment of the eighth aspect, the tissue engaging portion includes a discrete first electrode and a discrete second electrode. The discrete first electrode includes a first tissue contact portion, and the discrete second electrode includes a second tissue contact portion. In yet another more detailed embodiment, the tissue engaging portion includes a discrete intermediate electrode, and the discrete intermediate electrode includes an intermediate tissue contact portion. In another detailed embodiment, the tissue engaging portion includes a first insulator between the first electrode and the intermediate electrode and a second insulator between the intermediate electrode and the second electrode. In yet another detailed embodiment, the intermediate electrode includes at least two discrete intermediate electrodes arranged in sequence, and the magnitude of at least one electrical parameter varies incrementally between the at least two discrete intermediate electrodes arranged in sequence. In a more detailed embodiment, the first electrode, the intermediate electrode, and the second electrode are arranged in a line, and the first electrode is arranged as a first outermost electrode at a first end, and the second electrode is arranged as a second outermost electrode at a second end. In a more detailed embodiment, the first electrode is nested within the intermediate electrode, and the intermediate electrode is nested within the second electrode. In another more detailed embodiment, the first electrode is concentrically nested within the intermediate electrode, and the intermediate electrode is concentrically nested within the second electrode. In yet another more detailed embodiment, the intermediate electrode and the second electrode include nested, concentric, generally stadium-shaped ring electrodes disposed around the first electrode. In yet another more detailed embodiment, the first electrode is generally circular, the intermediate electrode is generally semi-circular and disposed around the first electrode, and the second electrode is generally semi-circular and disposed around the intermediate electrode.

[0024] In a more detailed embodiment of the eighth aspect, the intermediate electrode and the second electrode are truncated to form a generally bowtie shape. In yet another more detailed embodiment, the first electrode, the intermediate electrode, and the second electrode are truncated to form a generally bowtie shape. In another detailed embodiment, the tissue engaging portion includes a semiconductor element, and the semiconductor element includes an intermediate tissue contact portion. In yet another detailed embodiment, the semiconductor element has a resistivity greater than that of the target tissue. In a more detailed embodiment, the semiconductor element further includes a first tissue contact portion and a second tissue contact portion. In a more detailed embodiment, the end effector further includes a first electrical conductor electrically coupled to the semiconductor element near the first tissue contact portion, and the end effector further includes a second electrical conductor electrically coupled to the semiconductor element near the second tissue contact portion, and the first electrical conductor and the second electrical conductor are configured to receive electroablation energy from an ablation energy source. In another more detailed embodiment, the end effector further includes an intermediate electrical conductor electrically coupled to the semiconductor element near the intermediate tissue contact portion.

[0025] In yet another more detailed embodiment of the eighth aspect, an intermediate electrical conductor is electrically coupled to the first electrical conductor and the second electrical conductor such that when the first electrical conductor and the second electrical conductor are supplied with electroablation energy, the magnitude of at least one electrical parameter is different between the first electrical conductor, the intermediate electrical conductor, and the second electrical conductor, such that the magnitude of the intermediate tissue contact portion is between the magnitude of the first tissue contact portion and the magnitude of the second tissue contact portion. In yet another more detailed embodiment, the intermediate electrical conductor is electrically coupled to the first electrical conductor by a first resistor and the intermediate electrical conductor is electrically coupled to the second electrical conductor by a second resistor. In a further detailed embodiment, the tissue engaging portion includes a discrete first electrode and a discrete second electrode, the discrete first electrode including the first tissue contact portion and the discrete second electrode including the second tissue contact portion. In yet a further detailed embodiment, a semiconductor element is electrically coupled to the first electrode and the second electrode. In a more detailed embodiment, at least one electrical parameter includes potential. In a more detailed embodiment, at least one electrical parameter includes current. In another more detailed embodiment, the electroablation energy includes radiofrequency electrical energy. In yet another more detailed embodiment, the electroablation energy includes pulsed field ablation electrical energy. In yet another more detailed embodiment, the ablation device further includes a shaft disposed proximally on the end effector.

[0026] In a more detailed embodiment of the eighth aspect, the ablation device further includes a handle disposed proximally on the shaft. In yet another more detailed embodiment, the ablation device further includes at least one connection element configured to electrically couple the end effector to an external electroablation energy source.

[0027] A ninth aspect of the present disclosure is to provide a method of forming an ablation lesion in a target tissue, the method comprising: (a) positioning a tissue engaging portion of an end effector of an ablation device adjacent to the target tissue such that a first tissue contact portion of the tissue engaging portion is in electrical contact with the target tissue, a second tissue contact portion of the tissue engaging portion is in electrical contact with the target tissue, and an intermediate tissue contact portion of the tissue engaging portion between the first tissue contact portion and the second tissue contact portion is in electrical contact with the target tissue, and (b) forming an ablation lesion in the target tissue by applying electroablation energy to the end effector such that the magnitude of at least one electrical parameter or a combination of electrical parameters is different between the first tissue contact portion, the intermediate tissue contact portion, and the second tissue contact portion, such that the magnitude at the intermediate tissue contact portion is less than the magnitude at the first tissue contact portion and greater than the magnitude at the second tissue contact portion.

[0028] In a more detailed embodiment of the ninth aspect, applying electroablation energy to the end effector includes applying electroablation energy to a discrete first electrode including a first tissue contact portion and a discrete second electrode including a second tissue contact portion. In yet another more detailed embodiment, applying electroablation energy to the end effector includes applying electroablation energy to a discrete intermediate electrode including an intermediate tissue contact portion. In a further detailed embodiment, the intermediate electrode includes at least two discrete intermediate electrodes arranged sequentially, and applying electroablation energy to the discrete intermediate electrodes includes applying electroablation energy to at least two discrete intermediate electrodes arranged sequentially such that the magnitude of at least one electrical parameter varies incrementally between the at least two discrete intermediate electrodes arranged sequentially. In yet a further detailed embodiment, applying electroablation energy to the end effector includes applying electroablation energy to a semiconductor element including an intermediate tissue contact portion. In a more detailed embodiment, applying electroablation energy to the end effector includes applying electroablation energy to a semiconductor element that further includes a first tissue contact portion and a second tissue contact portion. In a more detailed embodiment, applying electroablation energy to the end effector includes applying electroablation energy from an ablation energy source to a first electrical conductor and a second electrical conductor, the first electrical conductor being electrically connected to the semiconductor element near the first tissue contact portion, and the second electrical conductor being electrically connected to the semiconductor element near the second tissue contact portion. In another more detailed embodiment, applying electroablation energy to the end effector includes applying electroablation energy from an ablation energy source to an intermediate electrical conductor, and the intermediate electrical conductor being electrically connected to the semiconductor element near the intermediate tissue contact portion.

[0029] In yet another more detailed embodiment of the ninth aspect, applying electroablation energy from an ablation energy source to an intermediate electrical conductor includes applying electroablation energy from the ablation source to the intermediate electrical conductor such that the magnitude of at least one electrical parameter or combination of electrical parameters is different between the first electrical conductor, the intermediate electrical conductor, and the second electrical conductor, such that the magnitude of the intermediate tissue contact is between the magnitude of the first tissue contact and the magnitude of the second tissue contact. In yet another more detailed embodiment, applying electroablation energy from the ablation source to the intermediate electrical conductor includes applying electroablation energy from the ablation source to the intermediate electrical conductor from the first electrical conductor via a first resistor and from the second electrical conductor via a second resistor. In a further detailed embodiment, applying electroablation energy to the end effector includes applying electroablation energy to a discrete first electrode including a first tissue contact and a discrete second electrode including a second tissue contact. In yet a further detailed embodiment, at least one electrical parameter includes potential. In a more detailed embodiment, at least one electrical parameter includes current. In a more detailed embodiment, the electroablation energy includes radiofrequency electrical energy. In another more detailed embodiment, the electroablation energy includes pulsed field ablation electrical energy. In yet another more detailed embodiment, the ablation device includes a shaft disposed proximally on the end effector, and positioning the tissue engaging portion of the end effector of the ablation device adjacent to the target tissue includes positioning the tissue engaging portion of the end effector of the ablation device using the shaft. In yet another more detailed embodiment, the ablation device includes a handle disposed proximally on the shaft, and positioning the tissue engaging portion of the end effector of the ablation device adjacent to the target tissue includes positioning the tissue engaging portion of the end effector of the ablation device using the handle. In yet another more detailed embodiment, the ablation device includes at least one connection element configured to electrically couple the end effector to an external ablation energy source, and applying electroablation energy to the end effector includes applying electroablation energy to the end effector via the at least one connection element.

[0030] A tenth aspect of the present disclosure is to provide a method of ablating tissue, the method comprising: (a) positioning an end effector of an ablation device such that a first contact portion, a second contact portion, and an intermediate contact portion interposed between the first contact portion and the second contact portion of the end effector physically touch the tissue, wherein the intermediate contact portion includes at least one of an electrode and a semiconductor, wherein the first contact portion is in electrical communication with a first electrode, and wherein the second contact portion is in electrical communication with a second electrode; and (b) applying electrical energy to the first electrode and the second electrode such that the magnitude of at least one electrical parameter or combination of electrical parameters is different between the first contact portion and the second contact portion, wherein the magnitude at the intermediate contact portion is less than the magnitude at the first contact portion and greater than the magnitude at the second contact portion.

[0031] The eleventh aspect of the present disclosure is to provide an ablation device for ablating tissue, the ablation device comprising: (a) an end effector including a first contact portion, a second contact portion, and an intermediate contact portion interposed between the first contact portion and the second contact portion, the intermediate contact portion including a plurality of intermediate electrodes, the first contact portion being in electrical communication with a first electrode, the second contact portion being in electrical communication with a second electrode, wherein the first electrode and the second electrode are spaced apart from each other by a first distance, wherein the first electrode and the intermediate contact portion are spaced apart from each other by a second distance, wherein the second electrode and the intermediate contact portion are spaced apart from each other by a third distance, wherein the first distance is greater than the second distance or the third distance, and wherein the surface area of at least one of the first electrode and the second electrode is a multiple of the surface area of any one of the plurality of intermediate electrodes, wherein when the end effector contacts the tissue, the first contact portion, the intermediate contact portion, and the second contact portion are electrically coupled, and wherein when the first electrode and the second electrode are supplied with electroablation energy, the magnitude of at least one electrical parameter is different between the first contact portion, the intermediate contact portion, and the second contact portion such that the magnitude at the intermediate contact portion is less than the magnitude at the first contact portion and greater than the magnitude at the second contact portion. The geometries of the first electrode, the second electrode, and the additional electrode may be uniform among them in width and length, or may vary in width and length, with the aim of customizing the applied power density according to the position or other characteristics such as the applied pressure.

[0032] One aspect of the present disclosure is to provide any method, process, device, or system including one or more of the elements described herein. One aspect of the present disclosure is to provide any combination of any one or more of the elements described herein.

[0033] Other aspects, features, and embodiments of the present disclosure will become apparent to those of ordinary skill in the art when the following description of specific example embodiments of the present disclosure is reviewed in conjunction with the accompanying drawings. While the features of the present disclosure may be discussed with respect to certain embodiments and figures below, all embodiments of the present disclosure may include one or more of the advantageous features discussed herein. In other words, while one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various embodiments of the present disclosure discussed herein. In a similar manner, while example embodiments may be discussed below as device, system, or method embodiments, it should be understood that such exemplary embodiments may be implemented in various devices, systems, and methods. Brief Description of the Drawings

[0034] The present disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings.

[0035] Figure 1A Perspective view of an ablation device according to one or more variations of the present disclosure.

[0036] Figure 1B Side view of a variant of an ablation device having a radiofrequency pen.

[0037] Figure 1C Side view of a variant of an ablation device having a radiofrequency pen applied to tissue.

[0038] Figure 1D Side view of a variant of an end effector having a rigid backing.

[0039] Figure 1E Side view of a variant of an end effector having a flexible backing.

[0040] Figure 1F Side view of a variant of an end effector having an array of multiple stacked electrodes.

[0041] Figure 1G Bottom view of a variant of an end effector having an array of multiple stacked electrodes.

[0042] Figure 2A Side view of a variant of an ablation device having a radiofrequency pen and a suction line.

[0043] Figure 2B Front view of a variant of an ablation device having a flexible backing and a vacuum line.

[0044] Figure 2C Front view of yet another variant of an ablation device having a flexible backing and a vacuum line.

[0045] Figure 2D Illustration of an ablation device applied to tissue Figure 2B front view.

[0046] Figure 2E Illustration of an ablation device applied to tissue Figure 2C front view.

[0047] Figure 3A Perspective view of an ablation device coupled to a generator and having an ablation clamp.

[0048] Figure 3B Side view of a variant of an ablation device having an ablation clamp.

[0049] Figure 4 Side view of a variant of an ablation device having an inflatable member.

[0050] Figure 5 Bottom view of a variant of an ablation device having concentric electrodes.

[0051] Figure 6 Bottom view of a variant of an ablation device having a semiconductor electrode in the center of an electrode array.

[0052] Figure 7 Perspective view of an ablation device coupled to various electrical devices.

[0053] Figure 8 Simplified schematic diagram of an example electrosurgical system including an example resistive voltage divider.

[0054] Figure 9 Simplified bottom view of an example electrode arrangement with a label showing an example maximum voltage.

[0055] Figure 10 Simplified bottom view of an example electrode arrangement with a label showing an example dimension.

[0056] Figure 11 Is a simplified bottom view of an example electrode arrangement with a label showing an example dimension.

[0057] Figure 12 Is a simplified bottom view of an example electrode arrangement with a label showing an example dimension.

[0058] Figure 13A Is a simplified bottom view of an example electrode arrangement with a label showing an example dimension.

[0059] Figure 13B Is a simplified bottom view of an example electrode arrangement with a label showing an example dimension.

[0060] Figure 14 Is a simplified bottom view of an example electrode arrangement disposed on a substrate.

[0061] Figure 15 Is a simplified bottom view of an example electrode arrangement with a label showing an example dimension.

[0062] Figure 16 Is a simplified bottom view of an example electrode arrangement with a label showing an example dimension.

[0063] Figure 17 Is a simplified bottom view of an example electrode arrangement with a label showing an example dimension.

[0064] Figure 18 Is a simplified bottom view of an example concentric electrode arrangement.

[0065] Figure 19 Cross-sectional view of an example dome-shaped end effector having an internal electrode.

[0066] Figure 20 Bottom view of an example tiled electrode arrangement.

[0067] Figure 21 Cross-sectional view of an exemplary electrosurgical device with an illustrated configuration for closed-loop active cooling.

[0068] Figure 22 Cross-sectional view of an exemplary electrosurgical device with an illustrated configuration for passive cooling.

[0069] Figure 23 Cross-sectional view of an exemplary end effector including an expandable member in the form of an inflatable element.

[0070] Figure 24 Perspective view of an exemplary electrode arrangement disposed on a substrate.

[0071] Figure 25 Perspective view of an exemplary electrode arrangement.

[0072] Figure 26 Perspective view of an exemplary end effector including an electrode arrangement.

[0073] Figure 27 Perspective view of an exemplary end effector including an electrode arrangement.

[0074] Figure 28 Perspective view of an exemplary end effector including an electrode arrangement.

[0075] Figure 29 Cross-sectional view of an exemplary current density in target tissue caused by a bipolar electrode, bipolar ablation device.

[0076] Figure 30 Cross-sectional view of an exemplary current density in target tissue caused by an exemplary ablation device including a first electrode, a second electrode, and four intermediate electrodes.

[0077] Figure 31 Illustrated is a cross-sectional view of an exemplary voltage potential in target tissue caused by an exemplary ablation device including an electrode arrangement generally similar to that shown in Figure 10 Cross-sectional view of an exemplary voltage potential in target tissue caused by an exemplary ablation device including an electrode arrangement generally similar to that shown in

[0078] Figure 32 Illustrated is a cross-sectional view of an exemplary temperature in target tissue caused by an exemplary ablation device including an electrode arrangement generally similar to that shown in Figure 10 Cross-sectional view of an exemplary temperature in target tissue caused by an exemplary ablation device including an electrode arrangement generally similar to that shown in

[0079] Figure 33A Simplified bottom view of an exemplary electrode arrangement including generally rectangular electrodes.

[0080] Figure 33B Simplified bottom view of an exemplary electrode arrangement including generally rectangular electrodes.

[0081] Figure 33C Is a simplified bottom view of an exemplary electrode arrangement including a generally rectangular electrode.

[0082] Figure 34A Is a simplified bottom view of an exemplary electrode arrangement including nested, generally circular and / or annular ring electrodes.

[0083] Figure 34B Is a simplified bottom view of an exemplary electrode arrangement including nested, generally circular and / or annular ring electrodes.

[0084] Figure 34C Is a simplified bottom view of an exemplary electrode arrangement including nested, generally circular and / or annular ring electrodes.

[0085] Figure 35A Is a simplified bottom view of an exemplary electrode arrangement including nested, generally oval ring electrodes.

[0086] Figure 35B Is a simplified bottom view of an exemplary electrode arrangement including nested, generally oval ring electrodes.

[0087] Figure 35C Is a simplified bottom view of an exemplary electrode arrangement including nested, generally oval ring electrodes.

[0088] Figure 35D Is a simplified bottom view of an exemplary electrode arrangement including nested, generally oval ring electrodes.

[0089] Figure 36A Is a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes.

[0090] Figure 36B Is a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes.

[0091] Figure 36C Is a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes.

[0092] Figure 36D Is a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes.

[0093] Figure 36E Is a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes.

[0094] Figure 36F Is a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes.

[0095] Figure 36GIs a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes.

[0096] Figure 36H Is a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes.

[0097] Figure 37A Is a simplified bottom view of an exemplary electrode arrangement including truncated, nested, generally circular and / or ring-shaped ring electrodes.

[0098] Figure 37B Is a simplified bottom view of an exemplary electrode arrangement including truncated, nested, generally circular and / or ring-shaped ring electrodes.

[0099] Figure 37C Is a simplified bottom view of an exemplary electrode arrangement including truncated, nested, generally circular and / or ring-shaped ring electrodes.

[0100] Figure 37D Is a simplified bottom view of an exemplary electrode arrangement including truncated, nested, generally circular and / or ring-shaped ring electrodes.

[0101] Figure 38A Is a front view of an exemplary electrode arrangement including a semiconductor electrode inserted between two outer electrodes.

[0102] Figure 38B Is Figure 38A A simplified elevation view of an embodiment of.

[0103] Figure 39 Is a simplified elevation view of an exemplary electrode arrangement including a semiconductor electrode including a semiconductor layer disposed on a metal conductor.

[0104] Figure 40 Is a simplified elevation view of an exemplary electrode arrangement including a semiconductor electrode having a conductor embedded therein.

[0105] Figure 41 Is a simplified bottom view illustrating a comparison of a symmetric electrode arrangement and an asymmetric electrode arrangement.

[0106] Figure 42 Is a simplified bottom view illustrating the dimensions of a variable rectangular electrode array.

[0107] Figure 43 Is a simplified bottom view illustrating the dimensions of a variable concentric electrode array. Detailed Description

[0108] The following detailed description presented in conjunction with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configuration in which the aspects described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various aspects. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring such aspects.

[0109] All examples and illustrative references are non-limiting and should not be used to limit the claims to the specific embodiments and examples described herein and their equivalents. For simplicity, reference numerals may be repeated between the various examples. Such repetition is for clarity only and does not determine the relationship between the corresponding embodiments. Finally, given the present disclosure, a particular feature described with respect to one aspect or embodiment may be applied to other disclosed aspects or embodiments of the present disclosure, even if not specifically shown in the drawings or described in the text.

[0110] The present disclosure includes various electrosurgical devices, and the electrosurgical devices include ablation devices. Figure 1A An exemplary ablation device 100 is shown, which provides a background for the various alternative embodiments and optional features described herein. Unless otherwise stated, any component, feature, method, etc. described herein may be used alone or in any combination with an ablation device generally similar to ablation device 100. The ablation device 100 may have an end effector 102 connected to the distal end of a shaft 104 and a handle 106 connected to the proximal end of the shaft 14. The shaft 14 may be straight and substantially rigid. However, depending on various considerations, a flexible, curved, extensible, articulated, or other shaft may also be used.

[0111] As Figure 1BAs seen, a connection element, such as cable 108, can be coupled to the handle 106 for connection to a device such as a power source (e.g., an external ablation energy source). The end effector 102 can extend along the longitudinal axis of the device 100 and can have a total width of approximately 26 mm. The end effector 102 can include a tissue engaging portion or working surface 114. As used herein, "working surface" can refer to a surface configured to contact target tissue. The working surface can include one or more individual surfaces, which can be continuous or discrete, and can include surfaces of any shape (flat, curved, concave, convex, etc.). The working surface 114 can include one or more insulators 112 (or insulator portions) and one or more electrodes 110, which can be capable of being energized with electroablation energy (such as with bipolar RF energy or pulsed field ablation energy). As used herein, "electrode" can refer to an element configured to deliver electrical energy to target tissue by contacting the target tissue. Each electrode 110 can include a smooth surface area for contacting tissue. A variety of different metals or low-resistance materials can be used for the electrodes, which are sufficiently conductive to transfer potential and current to the tissue via an ion current density. For example, the electrodes 110 can be made of copper, nickel, gold, stainless steel, platinum, platinum-iridium, titanium, tin, metal on Kapton, polymer-metal composites, hydrogels, or combinations thereof. The tissue engaging portion 114 can include a plurality of tissue contact locations, such as a first tissue contact location 114A, an intermediate tissue contact location 114B, and a third tissue contact location 114C. The intermediate tissue contact location 114B can be disposed between the first tissue contact location 114A and the third tissue contact location 114C. In the illustrated embodiment, the electrodes 110 can form the tissue contact locations 114A, 114B, 114C.

[0112] As Figure 1C seen, the stepped electrode configuration can result in applying energy to the tissue while ablating the tissue in order to limit temperature variations and extreme temperatures in the tissue (e.g., at tissue region 120). As a result, surface heating of the tissue can be reduced while still achieving proper ablation deep within the tissue ablation region 118 (e.g., ablation lesion) at a temperature of, for example, approximately 55°C. In some cases, the ablation depth after 80 seconds can be approximately 10 mm from the surface of the tissue. The electrodes can be independently controlled to produce a consistent ablation at a desired width while being adjusted for different tissue thicknesses or impedances. The power output can be adjusted based on the measured impedance and / or temperature of the tissue.

[0113] In other variations, one or more of the electrodes 110, such as one or more of the plurality of intermediate electrodes, may be replaced with a medium-resistance material, such as a semiconductor material having a conductivity of about 0.1 Siemens per meter (S / m) to 100 S / m. This medium-resistance semiconductor material is used to extend the electrodes toward the center, thereby reducing the voltage and current applied in the central region by virtue of the reduced conductivity of the material. As used herein, "semiconductor material" may refer to a material having electrical properties intermediate between those of a good conductor and a good insulator.

[0114] Figure 1D A cross-sectional view showing one variation of the rigid end effector 102. In this variation, the end effector 102 is generally rigid such that the electrodes 110 are substantially non-flexible. In the illustrated embodiment, the electrodes 110 are discrete. As used herein, "discrete" may refer to an electrode presenting a different tissue contact surface from other nearby components, such as other electrodes. For example, the end effector 102 may include a plastic insulator 122 for backing and interposed between the discrete electrodes 110. The plastic insulator 122 may be about 1-10 mm thick. The end effector 102 may also include a thermal conductor 124 within the plastic insulator 122 to assist in heat dissipation and minimize hot spots, although this is not critical to the overall function. The thickness of the thermal conductor 124 may be between 0.01-10 mm. A polyimide film or other electrical insulator 128 having a thickness of about 0.1 mm may be attached to the thermal conductor 124 via an adhesive or thermal bonding process 126. In an exemplary form, the thermal conductor may be a metal or metal alloy, including but not limited to aluminum and copper.

[0115] A plurality of electrodes 110 may be placed on the polyimide film or other electrical insulator 128 and spaced apart along the width of the end effector 102. The electrodes 110 may each have a width of about 0.1 mm to about 100 mm, a thickness of about 0.01 mm to 10 mm, and a length of about 20 mm. The electrodes 110 may be spaced apart by a gap having a width of about 0.5 mm. In Figure 1DIn the variant shown, the outer electrode 110 may have a width of about 4 mm, and the intermediate electrode may have a width of about 1.5 mm. The electrode width and configuration may vary as needed to reduce the current density, reduce surface heating, and increase the width of ablation. For example, in some embodiments, it may be advantageous to use relatively thin electrodes to reduce the electrode mass and / or reduce the heat flux leaving the electrodes. Additionally, multiple metal electrodes or higher resistance (e.g., semiconductor) electrodes adjacent to the metal electrodes may be used in other configurations to reduce the potential on the upper tissue surface. The total effective width of the electrode region (e.g., from one outer electrode to the other outer electrode) may be about 22.5 mm. Alternatively or in combination, the electrodes 110 may be arranged and stepped in a direction perpendicular to the longitudinal axis of the end effector to locally adjust the electrical output and thereby selectively ablate regions of the heart, where the electrical energy applied to these regions can be actively or passively controlled.

[0116] The electrode 110 may have sharp corners or rounded corners. Sharp corners may result in a higher local current density when heat is applied to the tissue. Optionally, the device 100 may include an active cooling mechanism for cooling the heart tissue and / or the device 100. The device may also optionally include a second electrical insulation layer to cover any electrical leads within the electrode 110.

[0117] The electrodes 110a, 110b, 110c, 110d, 110e, and 110f may be distributed in an array. The plurality of electrodes may include a first electrode 110a and a second electrode 110f on opposite sides of one or more intermediate electrodes 110b - 110e. During energy application, the plurality of electrodes may be configured such that there is a voltage difference between the first electrode 110a and the second electrode 110f. One or more sequentially arranged intermediate electrodes 110b - 110e may deliver a relatively smaller incremental voltage difference with respect to the outer electrodes. The electrode 110 may be a bipolar and / or multipolar electrode. The electrode 110 may be oriented perpendicular to the longitudinal axis of the end effector 102 or may be parallel to the longitudinal axis of the end effector 102 or offset at an angle between 0 degrees and 90 degrees.

[0118] The voltage potential difference between the first voltage and the second voltage can be greater than the voltage potential difference between the first electrode and the intermediate voltage of any one of the one or more intermediate electrodes. The electrode 110 can also be in the range between 0V and 75V, with a 15V interval between adjacent electrodes. For example, the electrode 110a can have a voltage of 75V, the electrode 110c can have a voltage of 45V, the electrode 110d can have a voltage of 30V, the electrode 110e can have a voltage of 15V, and the electrode 110f can have a voltage of 0V. The electrode 110 can also be in the range between 0V and 50V, with a 10V interval between adjacent electrodes. In other variations, the maximum voltage potential difference can be between 10V and 500V, where the intervals between the electrodes 110 are different. In other variations, the voltage interval between each electrode may not be constant. In other variations, other electrical parameters such as current or power can step between the electrodes instead of voltage.

[0119] The voltage potential difference between the electrodes 110 and the resulting gradient of the voltage of the end effector can be achieved. The voltage can be provided by the circuitry and / or resistors of the ablation device 100, which modify the potential applied to each electrode as originally sourced from a power source connected to the ablation device 100 (e.g., an ablation sensing unit (ASU) generator 308 as further described herein). The voltage can also be provided by an independent power source or a combination thereof.

[0120] The stepped electrodes limit the potential difference and thus limit the current density in the upper surface of the tissue while maintaining the current density deep in the tissue, which can result in safer and more efficient ablation. The voltage applied by the electrodes 110 can also be cycled on / off intermittently as needed to balance the ablation depth and the surface temperature.

[0121] Figure 1EA cross-sectional view showing one variant of the flexible end effector 102 is presented. A silicone insulator 130 can be used as a backing to provide flexibility to the end effector 102. The silicone insulator 130 can be approximately 1 - 10 mm thick. The insulator can alternatively be made of filled polyurethane or other elastomers, standard plastics, glass-filled or carbon-filled polymers, aluminum-clad polyimide, various metals with a sealed vacuum interior, or combinations thereof. A filled silicone or other elastomeric thermal conductor 132 can be provided towards the working surface 114 of the end effector 102, although this is not critical for the overall function. The filled elastomeric thermal conductor 132 can be approximately 0.1 - 10 mm thick. The thermal conductor 132 can alternatively be made of foamed polyurethane or other elastomers. Both the silicone insulator 130 and the filled silicone thermal conductor 132 can be flexible and can provide the end effector 102 with the ability to flex against heart tissue and conform to the curved surface of the heart, thereby providing more tissue contact area for ablation. The end effector 102 can also include a metallic thermal conductor 124 within the silicone insulator 130, although this is not critical for the overall function. The metallic thermal conductor 124 can be approximately 0.01 - 10 mm thick. A polyimide film 128 having a thickness of approximately 0.1 mm can be attached to the aluminum thermal conductor 124 via an adhesive or a thermal bonding process 126. The overall thermal efficiency and mechanical flexibility can be controlled by varying the layer thicknesses and material moduli of the components of the end effector 102.

[0122] Figure 1F A cross-sectional view showing a variant of the end effector 102 having multiple sets of electrodes 110 (e.g., two sets of six electrodes each) is presented. Multiple stacked rectangular electrode arrays can be positioned end-to-end on the tissue ablation device 100 to extend the surface length of the ablation region while maintaining electrical and thermal energy within the width and depth of the ablation region (e.g., three or more sets). The electrodes 110 can be positioned along the longitudinal axis of the end effector 102. Each set of electrodes 110 can have adjacent electrodes ranging between 0 V and 50 V with a 10 V spacing between adjacent electrodes. The electrodes 110 can also be in the range between 0 V and 75 V with a 15 V spacing between adjacent electrodes. The total effective region length can be approximately 45 mm, but can depend on the total number of sets of electrodes 110. Figure 1G A bottom view showing two sets of electrodes 110 positioned end-to-end on the end effector 102 is presented. In some variants, the effective width of the electrode region (e.g., from one outer electrode to the other) can be less than approximately 12 mm to pass through a trocar assembly for a minimally invasive surgical procedure.

[0123] Alternatively or in combination, the contact layer of the electrode 110 can be roughened and then coated with a thin polymer film having high ionic conductivity (e.g., ion-doped hydrogel) to reduce the impedance between the tissue and the metal, increase the capacitance, and thus reduce surface heating. Additionally, a heat sink behind the electrode 110 can help reduce the surface temperature and keep the upper surface of the end effector 102 cooled. The thickness of the heat sink can vary according to various factors (e.g., trocar diameter). The hydrogel can also be used to reduce the adhesion between the tissue and the electrode 110. The tissue current can increase with the increase in capacitance and with the reduction in the interfacial impedance between the electrode and the tissue. The interfacial impedance generally decreases with the increase in the electrode surface area. As the tissue is ablated and moisture is removed, the interfacial impedance and tissue conductivity decrease.

[0124] Figure 2A An ablation device 100 is shown having an end effector 102 that includes a suction line 200 along the longitudinal axis of the device 100. The suction line 200 can be disposed within the shaft 104 or along the outside of the shaft 104 (see FIG. 1). The suction line 200 can extend to an opening 202 within the end effector 102. The suction line 200 can provide a vacuum for adhering to the tissue without applying unnecessary external forces to the tissue. The vacuum can ensure more efficient ablation when the electrode 110 is connected. Efficient ablation can be measured by the time to achieve trans-wall penetration, the power required, the uniformity of heating, the depth of ablation, the lower dorsal temperature, less tissue surface damage, or a combination thereof.

[0125] As Figure 2B seen, the end effector 102 can have Figure 1E some properties of the flexible end effector 102, but has an opening 202 at the distal end of the suction line 200. The opening 202 can be made of an open-cell foam layer to support the overall structure and reduce dorsal heating, molded in a gap, molded in a connector to connect to the opening 202, or a combination thereof. A gap 204 can be fabricated within the electrode 110, the insulating film 128, the adhesive 126, the heat conductor 132, and the heat conductor 134 to connect the opening to the outer surface of the electrode 110.

[0126] Figure 2C Another variant of the end effector 102 is shown that includes a suction line 200 and has a rigid shell 206 along a silicone insulator 130. The silicone insulator 130 can have a thickness of about 6 mm or less. The electrode 110 can be fabricated separately from the opening 202 within the silicone insulator 130, allowing for easier fabrication. The rigid shell 206 can provide greater rigidity to the end effector 102 when the flexible edge 208 partially extends past the electrode 110.

[0127] AsFigure 2D As seen in, the end effector 102 can be placed next to target tissue, such as heart tissue 116. The end effector 102 can then be activated by a suction line 200 that provides a vacuum to the opening 202. The vacuum can travel through the gap 204 that passes through the electrodes 110 to provide a vacuum to pull the tissue 116 between the electrodes 110 to achieve a consistent electrical connection with the electrodes 110. Thus, the electrodes 110 can be oriented across the tissue, allowing current to penetrate deeper into the tissue. When needed, the end effector 102 can flex along its longitudinal axis or perpendicular to its longitudinal axis or in an alternative between the two.

[0128] Alternatively, as Figure 2E seen in, tissue can be drawn into the end effector 102 via the suction line 200 (see Figure 2A ). When the tissue is pulled against the end effector 102 or at least partially drawn into the end effector 102, the silicone insulator 130 of the end effector 102 can have a flexible edge 208 that extends partially past the electrodes 110, allowing the end effector 102 to cup and seal against the heart tissue. As the vacuum is applied, the heart tissue can be pulled against the electrodes 110, improving ablation efficiency by improving the contact between the electrodes 110 and the heart tissue, especially in minimally invasive procedures.

[0129] Figure 3A An ablation device 100 is shown having an end effector 102 connected to the distal end of a shaft 104 and a handle 106 connected to the proximal end of the shaft. In this variant, the end effector 102 can be a surgical ablation clamp such that RF energy flows between the two sides of the bipolar clamp. The surgical ablation clamp can provide increased electrical contact with the tissue and increased RF energy from both sides of the tissue, which can result in improved heating through the tissue thickness 102. The ablation clamp can reduce free liquid that can cause steam bursts during the procedure.

[0130] The end effector 102 may have a proximal jaw 300 and a distal jaw 302. The proximal jaw 300 and the distal jaw 302 are shown as being spaced apart for receiving tissue therebetween, but at least one of the proximal jaw 300 and the distal jaw 302 may be movable to clamp tissue therebetween. To this end, the proximal jaw 300 and the distal jaw 302 may be operatively coupled to a closure trigger 306 extending proximally from the handle 106 such that it can be operated with one hand, such that distal movement of the closure trigger 306 brings the proximal jaw 300 and the distal jaw 302 together. Similarly, proximal movement of the closure trigger 306 moves the proximal jaw 300 and the distal jaw 302 apart. The proximal jaw 300 and the distal jaw 302 are shown as extending at an angle from the shaft 104, but may be at any angle with respect to the shaft 104. Electrodes 110 may be disposed along the jaws 300, 302 and may apply energy to opposite sides of the tissue to cause energy to flow through the thickness of the tissue, thereby creating a transmural ablation. Each of the electrodes 110 may have a width of about 0.3 mm, a height of about 0.7 mm, and a length of about 63.5 mm.

[0131] As seen in Figure 3B a cross-sectional view of the end effector 102 in, the electrodes 110 may be disposed on the working surfaces of the jaws 300, 302. The electrodes 110 may be configured in any configuration as described previously or as described hereinafter. The jaws 300, 302 may be used to clamp tissue 116 before applying energy to the electrodes 110. Energy may be applied via an ASU generator 308, which will be described further herein.

[0132] The clamping pressure may press the jaws 300, 302 into the tissue to create a gap 304 typically less than the thickness of the tissue to be ablated.

[0133] As Figure 4 seen in, the end effector 102 may include an inflatable member 400. An air or gas passage 402 may be connected to the inflatable member 400 to selectively deflate and inflate the inflatable member 400. The air passage 402 may be disposed within the shaft 104 or along the outer side of the shaft 104. Alternatively or in combination, the inflatable member 400 may also be actuated within an actuation cable disposed within the shaft 104 or along the outer side of the shaft 104. The inflatable member 400 may be a balloon.

[0134] Figure 5Shows an electrode configuration in a nested concentric array. As used herein, "nested" may refer to an arrangement in which one or more electrodes are disposed generally within one or more other electrodes, such as where an inner electrode is partially or completely surrounded by an outer electrode. As used herein, "concentric" may refer to an arrangement in which one or more electrodes are disposed about a common center point or shape. Some example electrode arrays may be nested, concentric, or both nested and concentric. Electrode 110 may be in the form of active electrodes as circular electrode 500a and rings 500b-f, where each electrode in the array of electrodes is concentric with adjacent electrodes. The circular electrode 500a and the rings 500b-f may have a stepped voltage potential difference between adjacent electrodes. For example, the voltage potential difference may vary from the outermost ring 500f to the innermost electrode 500a at uniform or non-uniform intervals. Accordingly, the stepped voltage potential difference of the annularly distributed electrodes may result in minimizing surface heating at the tissue and providing deep ablation at the cardiac tissue.

[0135] Figure 6 Shows an apparatus 100 having one or more inner electrodes or resistive conductors (e.g., semiconductor electrodes) 600a, 600b at the center of an array 110 of electrodes. One or more resistive conductors (e.g., semiconductor electrodes) may be configured to reduce the potential difference across the electrodes and may be composed of an intermediate resistive material (e.g., from about 0.01 S / m to 1000 S / m). The resistive conductors 600a, 600b may be disconnected from an external circuit and may conduct current and reduce resistance between the outermost electrodes 100a, 100f, thereby reducing heating and temperature rise at the tissue surface. In some example embodiments, the resistive conductor and / or semiconductor element may have a resistivity greater than that of the target tissue. In some example embodiments, the resistive conductor and / or semiconductor element may have a resistivity approximately the same as that of the target tissue.

[0136] Figure 7 Shows an ablation device 100 having a cable 108 coupled thereto. The cable 108 may extend to a power source at its proximal end. During ablation, the power source may sense and measure tissue properties such as the impedance across the electrodes 110 (see, for example Figure 4 ) and may change electrical parameters such as power, current, and voltage. The ablation device 100 may be combined with a cable 108 that operably couples the ablation device 100 to a plurality of different common operating room equipment, devices, and / or sensors, which may include those for using the electrodes 110 ( Figure 1B) An ASU generator 308 or similar generator for forming an ablation lesion, a pacing monitor 700 for providing electrical stimulation to tissue, an impedance monitoring system 702 for measuring tissue impedance, and an electrocardiograph 708 for measuring at least one of the voltage, electrical conduction, conduction time, conduction velocity, and signal phase angle of the electrical signal that causes the heart to beat. Thus, the cable 108 in combination with an electrosurgical device such as the ablation device 100 can provide the surgeon with a single or multiple electrode device that can be used to replace multiple pre-existing electrode handheld devices for use in surgical procedures. A switch 706 can be added to the interconnect 704 to operably connect or disconnect one or more of the interconnected devices to the (multiple) electrodes of the surgical device. In addition, other circuit systems or components can be incorporated into the interconnect 704, such as diodes or switching circuit systems. The circuit system can protect the interconnected sensing equipment from the effects of the ablation energy, or provide real-time control or switching circuit systems. Thus, the surgeon can actuate the ASU generator 308 with a foot pedal, and the interconnect 704 will engage and protect sensitive equipment such as the electrocardiograph 708. For ablation device 100, each of the interconnected devices may be capable of being operably connected to or disconnected from the first polar electrode and / or the second polar electrode or any other electrode. If there are additional electrodes on the surgical device that can be connected to interconnect 704, then interconnect 704 can accommodate the additional electrodes. The electrodes can be connected in any combination to meet the needs of the energy delivery device or sensing device, and this can be achieved at interconnect 704. The power and / or current of each electrode may be different from the power and / or current of the adjacent electrode.

[0137] The total power output of the device 100 may be, for example, between 1 Watt and 200 Watts. The applied frequency of the device may be, for example, between 50 kHz and 5000 kHz. The voltage and current of each electrode may be in phase or out of phase with adjacent electrodes. The phase may be the time-dependent phase of the applied voltage potential. The voltage and current of each electrode may be a time-varying sine wave or a time-varying rectangular wave. Power may be applied in multiple time steps to heat deep in the tissue using heat conduction through the tissue without overheating the tissue surface.

[0138] Figure 8 A simplified schematic diagram of an example electrosurgical system 1000 including an example resistive voltage divider 1002 according to at least some aspects of the present disclosure is illustrated. The electrosurgical system 1000 can be substantially similar in structure and operation to other electrosurgical systems and related components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity. In the illustrated embodiment, the voltage divider includes a plurality of series-connected resistive elements (e.g., resistors R1, R2, R3, R4, and R5) electrically connected between a first input conductor 1004 and a second input conductor 1006.

[0139] In the illustrated embodiment, the first input conductor 1004 and the second input conductor 1006 include the bipolar output of the electrosurgical generator 1008. In the illustrated embodiment, the first intermediate conductor 1010 is electrically connected between the resistor Rl and the resistor R2; the second intermediate conductor 1012 is electrically connected between the resistor R2 and the resistor R3; the third intermediate conductor 1014 is electrically connected between the resistor R3 and the resistor R4; and the fourth intermediate conductor 1016 is electrically connected between the resistor R4 and the resistor R5.

[0140] In the illustrated embodiment, the first input conductor 1004 is electrically connected to the first electrode 1018, the second input conductor 1006 is electrically connected to the second electrode 1020, the first intermediate conductor 1010 is electrically connected to the first intermediate electrode 1022, the second intermediate conductor 1012 is electrically connected to the second intermediate electrode 1024, the third intermediate conductor 1014 is electrically connected to the third intermediate electrode 1026, and / or the fourth intermediate conductor 1016 is electrically connected to the fourth intermediate electrode 1028.

[0141] In some example embodiments, the resistors R1, R2, R3, R4, and R5 may have substantially equal resistances. For example, each of the resistors R1, R2, R3, R4, and R5 may include a 100 ohm resistor. Thus, some such embodiments may have substantially equal potential (e.g., voltage) differences between adjacent electrodes. In alternative embodiments, one or more of the resistors R1, R2, R3, R4, and R5 may have a resistance that is significantly different from that of at least one other of the resistors Rl, R2, R3, R4, and R5.

[0142] In the illustrated embodiment, the voltage divider 1002 is electrically interposed between the electrosurgical generator 1008 and the electrosurgical device 1030 including the electrodes 1018, 1020, 1022, 1024, 1026, 1028. In some example embodiments, the voltage divider 1002 may be disposed in an interface component that is configured to releasably electrically connect between the electrosurgical generator 1008 and the electrosurgical device 1030. In some alternative embodiments, the voltage divider 1002 may be provided as part of the electrosurgical generator 1008 such that the voltage divider is electrically connected within the electrosurgical generator 1008, and the electrosurgical device 1030 is configured to releasably electrically connect to the voltage divider 1002. In some alternative example embodiments, the voltage divider 1002 may be provided as part of the electrosurgical device 1030 such that the voltage divider 1002 is electrically connected within the electrosurgical device 1030, and the voltage divider 1002 is configured to releasably electrically connect to the electrosurgical generator 1008.

[0143] Figure 9is a simplified bottom view of an exemplary electrode arrangement 1100 with markings indicating an exemplary maximum voltage, according to at least some aspects of the present disclosure. The electrode arrangement 1100 may be generally similar in structure and operation to other electrode arrangements and related components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity. In the illustrated embodiment, the electrode arrangement 1100 includes a first electrode 1118, a second electrode 1120, a first intermediate electrode 1122, a second intermediate electrode 1124, a third intermediate electrode 1126, and / or a fourth intermediate electrode 1128, each of which is generally rectangular and together form a generally rectangular array.

[0144] The respective potential (voltage) of each electrode 1118, 1120, 1122, 1124, 1126, 1128 is marked as ΔV_max for the maximum voltage difference between the first electrode 1118 and the second electrode 1120 in Figure 9 which may correspond to the maximum voltage difference between the first input conductor 1004 and the second input conductor 1006 of the voltage divider 1002 supplied to Figure 8 The maximum voltage of the first electrode 1118 may be approximately +1 / 2ΔV_max, the maximum voltage of the second electrode 1120 may be approximately -1 / 2ΔV_max, the maximum voltage of the first intermediate electrode 1122 may be approximately +1 / 2ΔV_max - 1 / 5ΔV_max, the maximum voltage of the second intermediate electrode 1124 may be approximately +1 / 2ΔV_max - 2 / 5ΔV_max, the maximum voltage of the third intermediate electrode 1126 may be approximately +1 / 2ΔV_max - 3 / 5ΔV_max, and / or the maximum voltage of the fourth intermediate electrode 1128 may be approximately +1 / 2ΔV_max - 4 / 5ΔV_max. Although these maximum voltages are based on resistors Rl, R2, R3, R4, R5 having substantially equal resistances, those skilled in the art will be able to calculate similar maximum voltages for alternative arrangements including resistors Rl, R2, R3, R4, R5 having unequal resistances.

[0145] Figure 10 is a simplified bottom view of an exemplary electrode arrangement 1200 with markings indicating exemplary dimensions, according to at least some aspects of the present disclosure. The electrode arrangement 1200 may be generally similar in structure and operation to other electrode arrangements and related components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity. In particular, the electrode arrangement 1200 is generally similar to Figure 1F and Figure 1G the electrode arrangement illustrated and described above.

[0146] For clarity, various example embodiments may be described with reference to a length direction L and a width direction W. It will be understood that these designations are for descriptive consistency only and are not intended to limit the scope of the present disclosure to any particular orientation of the electrode arrangement relative to other components of the electrosurgical device.

[0147] In the illustrated embodiment, the electrode arrangement 1200 includes a repeating structure of a first electrode 1202, a second electrode 1204, and four intermediate electrodes 1206, 1208, 1210, 1212, each of these electrodes being generally rectangular and together forming a generally rectangular array. In this embodiment, the repeating structure is generally arranged as a mirror image such that the second electrodes 1204 are closest to each other, thereby avoiding adjacent electrodes having a V+ / V- (e.g., ΔV_max) voltage difference. Although Figure 10 an embodiment including two mirror image structures is illustrated, using any number of mirror image structures in a similar, generally repeating manner is also within the scope of the present disclosure.

[0148] In the illustrated embodiment, the first electrode 1202 and the second electrode 1204 have a width of 3.0 mm, and the intermediate electrodes 1206, 1208, 1210, 1212 have a width of 1.0 mm. In the illustrated embodiment, the gap between adjacent electrodes is 0.5 mm. Thus, the total width of the illustrated electrode arrangement is 25.5 mm. In the illustrated embodiment, the electrodes 1202, 1204, 1206, 1208, 1210, 1212 have an equal length of 7.25 mm. It will be understood that these dimensions are merely exemplary and should not be considered limiting in any way.

[0149] Figure 11 is a simplified bottom view of an example electrode arrangement 1300 with labeled exemplary dimensions all in accordance with at least some aspects of the present disclosure. The electrode arrangement 1300 may be generally similar in structure and operation to other electrode arrangements and related components described herein, and a repeated description of similar structures and operations is omitted for the sake of brevity. In particular, the electrode arrangement 1300 is generally similar to Figure 10 the electrode arrangement illustrated and described above.

[0150] In the illustrated embodiment, the electrode arrangement 1300 is similar to Figure 10 the mirror image repeating structure shown in Figure 10 except that the adjacent second electrodes 1204 in Figure 11 the embodiment of Figure 11The electrode arrangement 1300 includes, at each lateral end in a mirror arrangement, a first electrode 1302, a relatively wide second electrode 1304 that is generally centered, and four intermediate electrodes 1306, 1308, 1310, 1312 in each repeating structure. Although Figure 11 the illustrated embodiment shows an embodiment including two mirror structures, using any number of mirror structures in a similar, generally repeating manner is also within the scope of the present disclosure.

[0151] In the illustrated embodiment, the width of the first electrode 1302 is 4.0 mm, the width of the second electrode 1304 is 6.0 mm, and the widths of the intermediate electrodes 1306, 1308, 1310, 1312 are 1.5 mm. In the illustrated embodiment, the gap between adjacent electrodes is 0.5 mm. Thus, the total width of the illustrated electrode arrangement is 31.0 mm. In the illustrated embodiment, the electrodes 1302, 1304, 1306, 1308, 1310, 1312 have an equal length of 7.3 mm. It will be understood that these dimensions are merely exemplary and should not be considered limiting in any way.

[0152] Figure 12 is a simplified bottom view of an exemplary electrode arrangement 1400 with dimensions shown, all in accordance with at least some aspects of the present disclosure. The electrode arrangement 1400 may be generally similar in structure and operation to other electrode arrangements and related components described herein, and for the sake of brevity, a repeated description of similar structures and operations is omitted. In particular, the electrode arrangement 1400 is generally similar to Figure 1D and Figure 1E the electrode arrangements illustrated and described above.

[0153] In the illustrated embodiment, the widths of the first electrode 1402 and the second electrode 1404 are 6.0 mm, and the widths of the intermediate electrodes 1406, 1408, 1410, 1412 are 2.3 mm. In the illustrated embodiment, the gap between adjacent electrodes is 0.7 mm. Thus, the total width of the illustrated electrode arrangement is 24.7 mm. In the illustrated embodiment, the electrodes 1402, 1404, 1406, 1408, 1410, 1412 have an equal length of 7.3 mm. It will be understood that these dimensions are merely exemplary and should not be considered limiting in any way.

[0154] Figure 13A and Figure 13Bis a simplified bottom view of example electrode arrangements 1500A, 1500B in accordance with at least some aspects of the present disclosure, with dimensions shown as examples. The electrode arrangements 1500A, 1500B may be generally similar in structure and operation to other electrode arrangements and related components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity. In particular, the electrode arrangements 1500A, 1500B are generally similar to Figure 12 the electrode arrangements illustrated and described above, except that the electrode arrangements 1500A, 1500B are significantly longer in length L. In particular, although Figure 12 each electrode in the embodiment of Figure 12 has a length greater than its width, the width of the overall electrode arrangement of Figure 13A and Figure 13B is greater than its length. In contrast, in the embodiments of

[0155] each electrode has a length greater than its width, and the length of the overall electrode arrangements 1500A, 1500B is greater than its width. Figure 13A In the illustrated embodiment, the first electrodes 1502A, 1502B and the second electrodes 1504A, 1504B have a width of 4.0 mm, and the intermediate electrodes 1506A, 1506B, 1508A, 1508B, 1510A, 1510B, 1512A, 1512B have a width of 1.5 mm. In the illustrated embodiment, the gap between adjacent electrodes is 0.5 mm. Thus, the total width of the illustrated electrode arrangement is 16.5 mm. In the embodiment illustrated in Figure 13B the electrodes 1502A, 1504A, 1506A, 1508A, 1510A, 1512A have equal lengths of 25.0 mm. In the embodiment illustrated in

[0156] the electrodes 1502B, 1504B, 1506B, 1508B, 1510B, 1512B have equal lengths of 50.0 mm. It will be understood that these dimensions are merely exemplary and should not be considered limiting in any way.

[0157] Typically, in some example embodiments in accordance with at least some aspects of the present disclosure, the first and second electrodes may be about 6.0 mm wide, the middle electrode may be about 2.0 - 3.0 mm wide, and for a total width of about 25.0 - 30.0 mm, the gap between the electrodes may be about 0.5 - 1.5 mm. In similar alternative embodiments, these dimensions may vary by about + / - 25% of these values.

[0158] Figure 14 is a simplified bottom view of an example electrode arrangement 1600 disposed on a substrate 1602 in accordance with at least some aspects of the present disclosure. The electrode arrangement 1600 may be generally similar in structure and operation to other electrode arrangements and related components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity. In particular, the electrode arrangement 1600 is generally similar to Figure 11 (having an extended length L) and those illustrated in FIG. 13 (having repeated electrodes) and described above.

[0159] In the illustrated embodiment, the substrate 1602 is 31.0 mm wide and 250.0 mm long, and the electrode arrangement 1600 is 31.0 mm wide and 50.0 mm long. In this embodiment, the electrode arrangement 1600 is disposed at one end of the substrate 1602.

[0160] Adjacent to the electrode arrangement 1600 on the substrate 1602 is a connection / soldering area 1604. The connection / soldering area 1604 includes a plurality of electrical conductors 1606 and pads 1608. Generally, the electrical conductors 1606 are configured to electrically couple a particular electrode and the pad 1608 in a desired electrical configuration. The pads 1608 are configured to facilitate soldering connections to wires or other conductors, which may be electrically connected to, for example, an electrosurgical generator and / or sensing equipment. In the illustrated embodiment, the connection / soldering area 1604 is approximately 20.0 - 25.0 mm long. In use, the electrode arrangement 1600 portion of the substrate 1602 is exposed to allow contact with the target tissue. The remaining portion of the substrate 1602 (e.g., the portion including the connection / soldering area 1604) may be housed within an end effector or shaft, or may otherwise be protected and / or insulated from contact with the operating area.

[0161] In the illustrated embodiment, the electrode arrangement 1600 and the substrate 1602 are constructed in the form of a flexible printed circuit. The substrate may include, for example polyimide, and / or the electrodes may be composed of, for example, copper plated with nickel and gold. In this example embodiment, the substrate may be about 0.05 mm thick and / or the electrodes may be about 0.036 mm thick. In some example embodiments, the substrate and / or the electrodes may be generally flexible, such as to conform to other end effector components and / or anatomical tissue.

[0162] Figure 15 is a simplified bottom view of an exemplary electrode arrangement 1620 with markings showing exemplary dimensions, in accordance with at least some aspects of the present disclosure. The electrode arrangement 1620 may be generally similar in structure and operation to other electrode arrangements and related components described herein, and for the sake of brevity, repeated descriptions of similar structures and operations are omitted. In particular, the electrode arrangement 1620 is generally similar to Figure 13A the electrode arrangement illustrated and described above, except that the electrode arrangement 1620 includes at least one electrode having a different length, while Figure 13A all of the electrodes in the embodiment of

[0163] In the illustrated embodiment, the first electrode 1622 and the second electrode 1624 have a width of 4.0 mm, and the intermediate electrodes 1626, 1628, 1630, 1632 have a width of 1.5 mm. In the illustrated embodiment, the gap between adjacent electrodes is 0.5 mm. Accordingly, the total width of the illustrated electrode arrangement 1620 is 16.5 mm. In the illustrated embodiment, the first electrode 1622 and the second electrode 1624 are shorter than the intermediate electrodes 1626, 1628, 1630, 1632. Additionally, in the illustrated embodiment, the intermediate electrodes 1626, 1632 closest to the first electrode 1622 and the second electrode 1624 are shorter than the intermediate electrodes 1628, 1630 disposed centrally. That is, the centrally disposed intermediate electrodes 1628, 1630 are the longest in length, and the outer first electrode 1622 and the second electrode 1624 are the shortest. In the illustrated embodiment, the centrally disposed intermediate electrodes 1628, 1630 are 25 mm in length. Generally, electrode dimensions may be selected to produce a desired ablation shape. It will be understood that these dimensions are merely exemplary and should not be considered limiting in any way.

[0164] Figure 16 is a simplified bottom view of an exemplary electrode arrangement 1640 with markings showing exemplary dimensions, in accordance with at least some aspects of the present disclosure. The electrode arrangement 1640 may be generally similar in structure and operation to other electrode arrangements and related components described herein, and for the sake of brevity, repeated descriptions of similar structures and operations are omitted. In particular, the electrode arrangement 1640 is generally similar to Figure 13A the electrode arrangement illustrated and described above, except that the electrode arrangement 1640 includes at least one electrode having a different shape (e.g., generally trapezoidal), while Figure 13A all of the electrodes in the embodiment of

[0165] In the illustrated embodiment, the first electrode 1642 and the second electrode 1644 have a width of 4.0 mm, and the intermediate electrodes 1646, 1648, 1650, 1652 have a width of 1.5 mm. In the illustrated embodiment, the gap between adjacent electrodes is 0.5 mm. Thus, the total width of the illustrated electrode arrangement 1650 is 16.5 mm. In the illustrated embodiment, the first electrode 1652 and the second electrode 1644 are generally trapezoidal, with the shorter of the parallel sides disposed outwardly away from the intermediate electrodes 1646, 1648, 1650, 1652. The intermediate electrodes 1646, 1648, 1650, 1652 are generally rectangular. In the illustrated embodiment, the electrodes are 25 mm long. Generally, the electrode shape can be selected to produce a desired ablation shape. It will be understood that these dimensions are merely exemplary and should not be considered limiting in any way.

[0166] Figure 17 is a simplified bottom view of an exemplary electrode arrangement 1660 with labeled exemplary dimensions in accordance with at least some aspects of the present disclosure. The electrode arrangement 1660 may be generally similar in structure and operation to other electrode arrangements and related components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity. In particular, the electrode arrangement 1660 is generally similar to Figure 13A the electrode arrangement illustrated and described above, except that the electrode arrangement 1660 includes at least one gap between electrodes having different widths, while all gaps in Figure 13A the embodiment of Figure 13A are generally uniform, while all intermediate electrodes have

[0167] In the illustrated embodiment, the first electrode 1662 and the second electrode 1664 have a width of 4.0 mm, the intermediate electrodes 1666, 1672 closest to the first and second electrodes have a width of 1.5 mm, and the intermediate electrodes 1668, 1670 disposed centrally have a width of 0.75 mm. In the illustrated embodiment, the gaps 1674, 1676 between the first electrode 1662 and the second electrode 1624 and their respective adjacent intermediate electrodes 1666, 1672 are 0.5 mm. In the illustrated embodiment, the gaps 1678, 1680 between the outer intermediate electrodes 1666, 1672 and the centrally disposed intermediate electrodes 1668, 1670 are 1.0 mm. In the illustrated embodiment, the gap 1682 between the centrally disposed intermediate electrodes 1668, 1670 is 1.0 mm. Thus, the total width of the illustrated electrode arrangement 1660 is 16.5 mm. In the illustrated embodiment, the electrodes are 25 mm long. Generally, the gap widths can be selected to produce a desired ablation shape. It will be understood that these dimensions are merely exemplary and should not be considered limiting in any way.

[0168] Figure 18 is a simplified bottom view of an exemplary nested, concentric electrode arrangement 1720 in accordance with at least some aspects of the present disclosure. The electrode arrangement 1720 may be generally similar in structure and operation to other electrode arrangements and related components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity. In particular, the electrode arrangement 1720 is generally similar to Figure 5 the electrode arrangement illustrated and described above, except that the electrode arrangement 1720 includes a generally annular central electrode 1724, while Figure 5 the central electrode 500a of the embodiment of

[0169] In the illustrated embodiment, the first (e.g., outer) electrode 1722 and the second (e.g., central) electrode 1724 are concentrically disposed. In the illustrated embodiment, four generally annular intermediate electrodes 1726, 1728, 1730, 1732 are concentrically disposed with the first electrode 1722 and the second electrode 1724 and are radially disposed between the first electrode 1722 and the second electrode 1724. In the illustrated embodiment, the electrode arrangement 1720 includes a generally circular central gap 1734 and annular gaps between adjacent electrode pairs.

[0170] Figure 19A cross-sectional view of an example dome-shaped end effector 1820 having internal electrodes in accordance with at least some aspects of the present disclosure is shown. In the illustrated embodiment, the end effector 1820 includes a structural element 1822 and a plurality of electrodes 1824, 1826, 1828, 1830, 1832, 1834. The structural element 1822 forms a generally concave portion, and the electrodes 1824, 1826, 1828, 1830, 1832, 1834 are disposed on its inner surface 1836. Accordingly, the electrodes provide a generally concave tissue contact surface 1838. The size and arrangement of the electrodes 1824, 1826, 1828, 1830, 1832, 1834 may be similar to other electrode arrangements described herein, and a repetitive description is omitted for the sake of brevity. In some example embodiments, the structural element 1822 may be substantially rigid when subjected to expected forces during intended use. In some example embodiments, the structural element 1822 may be at least partially deformable (e.g., elastically and / or plastically) when subjected to expected forces during intended use.

[0171] Figure 20 A bottom view of an example tiled rectangular electrode arrangement 1850 in accordance with at least some aspects of the present disclosure is shown. In the illustrated embodiment, the tiled arrangement includes a first electrode arrangement 1200 disposed adjacent to a second electrode arrangement 1200 in a length direction ( Figure 10 ). In the illustrated embodiment, a gap 1852 is interposed between the first electrode arrangement 1200 and the second electrode arrangement 1200 in the length direction. Although Figure 20 two electrode arrangements 1200 disposed in a length direction are shown, alternative embodiments may include tiled arrangements of two or more other electrode arrangements that are laterally offset and / or linearly offset and / or angularly offset, such as those disclosed herein.

[0172] Figure 21 A cross-sectional view of an example electrosurgical device 1860 configured for closed-loop active cooling in accordance with at least some aspects of the present disclosure is shown. In the illustrated embodiment, the electrosurgical device 1860 includes a plurality of electrodes 1862 disposed on an end effector 1864, generally as described elsewhere herein. A supply conduit 1866 is arranged to deliver a cooling fluid to an internal chamber 1868 of the end effector 1864. A return conduit 1870 is arranged to direct the cooling fluid away from the internal chamber 1868 of the end effector 1864. The end effector 1864 is configured such that the cooling fluid flowing through the internal chamber 1868 removes heat from the electrodes 1862. Some embodiments may include a heat conductor, such as those referenced above Figure 1DThe described thermal conductor 124 can be arranged to conduct heat from the electrode 1862 to a cooling fluid within the internal chamber 1868. Example cooling fluids can include, for example but not limited to, water and / or saline solutions. The supply conduit 1866 and / or the return conduit 1870 can be operatively coupled to a source of the cooling fluid and / or a receptacle for the used cooling fluid. Alternatively, the return conduit 1870 can be omitted, and the cooling fluid can be discharged from the electrosurgical device 1860 and delivered to the surgical space.

[0173] Figure 22 FIG. shows a cross-sectional view of an example electrosurgical device 1880 constructed for passive cooling in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrosurgical device 1880 includes a plurality of electrodes 1882 disposed on the end effector 1884, generally as described elsewhere herein. One or more heat sinks 1886 are disposed in thermal contact with the electrodes 1882 such that heat from the electrodes 1882 can flow into the heat sinks 1886. In some example embodiments, the heat sinks 1886 can be constructed of a solid material (such as a metal) having a relatively high thermal mass and / or a relatively high thermal conductivity.

[0174] Figure 23 FIG. shows a cross-sectional view of an example end effector 1920 including an expandable member in the form of an inflatable element 1922 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the end effector 1920 includes a first electrode array 1924 and a second electrode array 1926 disposed on one or more of its outer surfaces. The end effector 1920 can be reconfigured between a collapsed configuration and an expanded configuration ( Figure 23 as shown) such as by inflation and / or deflation of the inflatable element 1922. The inflatable element 1922 can be disposed generally internally within the end effector 1920 and / or can act as a structural element of the end effector 1920. In the illustrated embodiment, when the end effector is in the expanded configuration, each electrode array 1924, 1926 provides a respective generally convex tissue contact surface 1928, 1930. The size and arrangement of the electrode arrays 1924, 1926 can be similar to other electrode arrangements described herein, and repeated description is omitted for the sake of brevity.

[0175] Figures 24 to 28 FIG. shows an example embodiment including various optional features and configurations in accordance with at least some aspects of the present disclosure. Figure 24Perspective view of an exemplary generally rectangular electrode arrangement 1700 disposed on a substrate 1702 in accordance with at least some aspects of the present disclosure. The electrode arrangement 1700 and the substrate 1702 may be generally similar in structure and operation to other electrode arrangements and associated components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity. In particular, the electrode arrangement 1700 and the substrate are generally similar to those illustrated and described above in Figure 14 Those illustrated and described above. In the illustrated embodiment, the connection / soldering region 1704 is shown having respective wires 1706 soldered to each pad 1708.

[0176] Figure 25 Perspective view of an exemplary electrode arrangement 1800 in accordance with at least some aspects of the present disclosure. The electrode arrangement 1800 may be generally similar in structure and operation to other electrode arrangements and associated components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity. In particular, the electrode arrangement 1800 substrate is generally similar to those illustrated and described above in FIG. 13. The soldering connections 1802 are visible in the connection / soldering region 1804 adjacent to the active electrode arrangement 1800. Additionally, the illustrated embodiment includes a plurality of suction openings 1806.

[0177] Figure 26 Perspective view of an exemplary end effector 1900 including an electrode arrangement 1902 in accordance with at least some aspects of the present disclosure. The end effector 1900 may be generally similar in structure and operation to other end effectors and associated components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity. In particular, the electrode arrangement 1902 is generally similar to the electrode arrangements Figure 11 Illustrated and described above.

[0178] Figure 27 Perspective view of an exemplary end effector 2000 including an electrode arrangement 2002 in accordance with at least some aspects of the present disclosure. The end effector 2000 may be generally similar in structure and operation to other end effectors and associated components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity. In particular, the electrode arrangement 2002 is generally similar to the electrode arrangements illustrated and described above in FIG. 13. Additionally, the illustrated embodiment includes a plurality of suction openings 2004. In the illustrated embodiment, the electrode arrangement 2002 may be approximately 17.0 mm × approximately 25.0 mm.

[0179] Figure 28FIG. is a perspective view of an exemplary end effector 2100 including an electrode arrangement 2102 in accordance with at least some aspects of the present disclosure. The end effector 2100 may be generally similar in structure and operation to other end effectors and related components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity. In particular, the electrode arrangement 2102 is generally similar to Figure 11 the electrode arrangement illustrated and described above.

[0180] Figure 29 FIG. is a cross-sectional view of an exemplary current density in target tissue 2200 caused by a bipolar ablation device with bipolar electrodes 2202, 2204. Although the present disclosure contemplates that ablation devices having configurations similar to Figure 29 those shown have been used safely and effectively, Figure 29 it is shown that such devices can cause high current densities at the surfaces of electrodes 2202, 2204 and near the surface of tissue 2200 between electrodes 2202, 2204. As a result, the effective ablation volume 2206 can be limited, such as to near the surface of tissue 2200.

[0181] Figure 30 FIG. is a cross-sectional view of an exemplary current density in target tissue 2300 caused by an exemplary ablation device including a first electrode 2302, a second electrode 2304, and four intermediate electrodes 2306, 2308, 2310, 2312 in accordance with at least some aspects of the present disclosure. For example, Figure 30 the electrode arrangement illustrated in Figure 12 may be generally similar to the electrode arrangement illustrated and described above. As Figure 30 shown in Figure 29 and compared to the current density illustrated in Figures 9 to 14 this exemplary device causes a generally less concentrated current density near the surface of tissue 2300 and is capable of achieving a generally deeper penetration of the current density. As a result, the effective ablation volume 2314 can be larger and / or can extend deeper into tissue 2300. Generally, for some embodiments in accordance with at least some aspects of the present disclosure, a greater width between electrodes 2302 and 2304 may, to some extent, result in deeper ablation. If the electrodes are spaced too far apart, the current density may be too low to adequately heat the tissue. For example, to achieve a tissue ablation depth of approximately 5 - 15 mm, when operating at a power between about 10 watts and about 50 watts and an AC frequency between about 400 kHz and about 450 kHz, the width between the outermost points on the two outer electrodes (e.g., those having the greatest voltage difference) may be between about 10 mm and about 30 mm, where some six - electrode configurations are similar to

[0182] Figure 31A cross-sectional view of an example potential in target tissue 2400 caused by an example ablation device including an electrode arrangement 2402 that is generally similar to that shown in Figure 10 is shown, and Figure 32 A cross-sectional view of an example temperature distribution in target tissue 2400 caused by an example ablation device including an electrode arrangement 2402 that is generally similar to that shown in Figure 10 is shown, all in accordance with at least some aspects of the present disclosure. Generally, compared to embodiments including a dual-electrode bipolar ablation device, potential and temperature changes are distributed substantially more uniformly in the target tissue. That is, in a dual-electrode bipolar ablation device, compared to an electrode arrangement 2402 that is generally similar to that shown in Figure 10 , potential and / or temperature changes may be more concentrated, such as at locations near the electrodes.

[0183] Figures 33A to 33C An alternative example electrode arrangement including generally rectangular electrodes arranged in a generally rectangular array is shown. These electrode arrangements may be generally similar in structure and operation to other electrode arrangements and related components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity.

[0184] Figure 33A is a simplified bottom view of an example electrode arrangement 3300 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3300 includes a relatively wide (e.g., about 4 mm) first electrode 3302 and a second electrode 3304, and four relatively narrow (e.g., about 1.5 mm) intermediate electrodes 3306, 3308, 3310, 3312 disposed therebetween. The spacing between the electrodes 3302, 3304, 3306, 3308, 3310, 3312 may be uniform, about 0.2 mm. The electrode arrangement 3300 may have a length of about 8 mm.

[0185] Figure 33B is a simplified bottom view of an example electrode arrangement 3330 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3330 includes a relatively wide (e.g., about 4 mm) first electrode 3332 and a second electrode 3334, and four relatively narrow (e.g., about 1.5 mm) intermediate electrodes 3336, 3338, 3340, 3342 disposed therebetween. The spacing between the electrodes 3332, 3334, 3336, 3338, 3340, 3342 may be uniform, about 0.5 mm. The electrode arrangement 3330 may have a length of about 25 mm.

[0186] Figure 33Cis a simplified bottom view of an example electrode arrangement 3360 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3360 includes a relatively wide (e.g., about 6 mm) first electrode 3362 and a second electrode 3364, and four relatively narrow (e.g., about 0.5 mm) intermediate electrodes 3366, 3368, 3370, 3372 disposed therebetween. The spacing between electrodes 3362, 3364, 3366, 3368, 3370, 3372 may be uniform, about 0.1 mm. The electrode arrangement 3360 may have a length of about 25 mm.

[0187] Figures 34A to 34C The illustration includes alternative example electrode arrangements including nested, generally circular and / or annular ring electrodes. These electrode arrangements may be generally similar in structure and operation to other electrode arrangements and related components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity.

[0188] Figure 34A is a simplified bottom view of an example electrode arrangement 3400 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3400 includes a relatively wide (e.g., about 4 mm) outer annular electrode 3402, a relatively wide (e.g., about 7 mm) circular inner electrode 3404, and four relatively narrow (e.g., about 1.5 mm) intermediate electrodes 3406, 3408, 3410, 3412 disposed therebetween. In this embodiment, electrodes 3402, 3404, 3406, 3408, 3410, 3412 may be concentrically arranged, and the spacing between electrodes 3402, 3404, 3406, 3408, 3410, 3412 may be uniform, about 0.2 mm. The electrode arrangement 3400 may have an overall diameter of about 29 mm.

[0189] Figure 34B is a simplified bottom view of an example electrode arrangement 3420 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3420 includes a relatively wide (e.g., about 4 mm) outer annular electrode 3422 spaced about 5 - 6 mm from a relatively wide (e.g., about 15.6 mm) circular inner electrode 3424, and two relatively narrow (e.g., about 2.5 mm) intermediate electrodes 3426, 3428 disposed therebetween. The ratio of the surface area of the inner electrode 3424 to the surface area of the outer electrode 3422 is about 1:2. In this embodiment, electrodes 3422, 3424, 3426, 3428 may be concentrically arranged, and the spacing between electrodes 3422, 3424, 3426, 3428 may be uniform, about 0.2 mm. The electrode arrangement 3420 may have an overall diameter of about 34.8 mm.

[0190] Figure 34CIs a simplified bottom view of an example electrode arrangement 3460 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3460 includes a relatively wide (e.g., about 4 mm) outer annular electrode 3462, a relatively wide (e.g., about 15.6 mm) annular inner electrode 3464 having a central opening 3466 (e.g., about 4 mm), and two relatively narrow (e.g., about 2.5 mm) intermediate electrodes 3468, 3470 disposed therebetween. In this embodiment, the electrodes 3442, 3444, 3446, 3448 may be concentrically arranged, and the spacing between the electrodes 3442, 3444, 3446, 3448 may be uniform, about 0.2 mm. The electrode arrangement 3440 may have an overall diameter of about 34.8 mm.

[0191] Figures 35A to 35D The illustration includes alternative example electrode arrangements of nested, generally oval-shaped ring electrodes. These electrode arrangements may be generally similar in structure and operation to other electrode arrangements and related components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity.

[0192] Figure 35A Is a simplified bottom view of an example electrode arrangement 3500 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3500 includes a relatively long (e.g., about 4 mm) outer oval electrode 3502, a relatively long (e.g., about 16.4 mm) oval inner electrode 3504, and four relatively narrow (e.g., about 1.5 mm) intermediate electrodes 3506, 3508, 3510, 3512 disposed therebetween. In this embodiment, the electrodes 3502, 3504, 3506, 3508, 3510, 3512 may be concentrically arranged, and the spacing between the electrodes 3502, 3504, 3506, 3508, 3510, 3512 may be a uniform length of about 0.2 mm. In the width direction, the electrodes and electrode spacing are uniformly divided (scaled) by the same factor of 2. The electrode arrangement 3500 may have an overall length of about 38.4 mm and an overall width of about 19.2 mm.

[0193] Figure 35B Is a simplified bottom view of an example electrode arrangement 3520 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3520 includes a relatively long (e.g., about 4 mm) outer oval electrode 3522 and a relatively long (e.g., about 29.4 mm) oval inner electrode 3524, which may be concentrically arranged and spaced apart by about 0.5 mm in the length direction. In the width direction, the electrodes and electrode spacing are uniformly divided (scaled) by the same factor of 2. The electrode arrangement 3520 may have an overall length of about 38.4 mm and an overall width of about 19.2 mm.

[0194] Figure 35C is a simplified bottom view of an example electrode arrangement 3540 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3540 includes the same dimensions as the Figure 35A electrode arrangement 35A therein, except that all dimensions are multiplied by a factor of 1.25.

[0195] Figure 35D is a simplified bottom view of an example electrode arrangement 3580 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3580 includes a relatively long (e.g., about 4 mm) outer oval electrode 3582, a relatively long (e.g., about 18 mm) oval inner electrode 3584, and two relatively narrow (e.g., about 3 mm) intermediate electrodes 3586, 3588 disposed therebetween. In this embodiment, the electrodes 3582, 3584, 3586, 3588 may be concentrically arranged, and the spacing between the electrodes 3582, 3584, 3586, 3588 may be uniform, about 0.3 mm. In the width direction, the electrodes and the electrode spacing are uniformly divided (scaled) by the same factor of 2. The electrode arrangement 3580 may have an overall length of about 39.8 mm and an overall width of about 19.9 mm.

[0196] Figures 36A to 36H The illustration includes alternative example electrode arrangements of nested, generally stadium-shaped ring electrodes. As used herein, "stadium-shaped" may describe a generally rectangular shape having semi-circles at opposite short ends. These electrode arrangements may be generally similar in structure and operation to other electrode arrangements and related components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity.

[0197] Figure 36A is a simplified bottom view of an example electrode arrangement 3600 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3600 includes a relatively long (e.g., about 4 mm) outer stadium-shaped electrode 3602, a relatively long (e.g., about 19.4 mm) stadium-shaped inner electrode 3604 having a relatively narrow width (e.g., about 3 mm), and four relatively narrow (e.g., about 0.2 mm) intermediate electrodes 3606, 3608, 3610, 3612 disposed therebetween. In this embodiment, the electrodes 3602, 3604, 3606, 3608, 3610, 3612 may be concentrically arranged, and the spacing between the electrodes 3602, 3604, 3606, 3608, 3610, 3612 may be uniform, about 0.1 mm. The electrode arrangement 3600 may have an overall length of about 30 mm and an overall width of about 11.6 mm.

[0198] Figure 36Bis a simplified bottom view of an example electrode arrangement 3620 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3620 includes a relatively long (e.g., about 2 mm) outer stadium-shaped electrode 3622, a relatively long (e.g., about 17.4 mm) stadium-shaped inner electrode 3624 having a relatively narrow width (e.g., about 1.2 mm), and four relatively narrow (e.g., about 0.2 mm) intermediate electrodes 3626, 3628, 3630, 3632 disposed therebetween. In this embodiment, the electrodes 3622, 3624, 3626, 3628, 3630, 3632 may be concentrically arranged, and the spacing between the electrodes 3622, 3624, 3626, 3628, 3630, 3632 may be uniform, about 0.1 mm. The electrode arrangement 3620 may have an overall length of about 24 mm and an overall width of about 7.8 mm.

[0199] Figure 36C is a simplified bottom view of an example electrode arrangement 3640 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3640 includes a relatively narrow (e.g., about 1 mm) outer stadium-shaped electrode 3642, a relatively long (e.g., about 19.4 mm) stadium-shaped inner electrode 3644 having a relatively large width (e.g., about 4 mm), and four relatively narrow (e.g., about 0.2 mm) intermediate electrodes 3646, 3648, 3650, 3652 disposed therebetween. In this embodiment, the electrodes 3642, 3644, 3646, 3648, 3650, 3652 may be concentrically arranged, and the spacing between the electrodes 3642, 3644, 3646, 3648, 3650, 3652 may be uniform, about 0.1 mm. The electrode arrangement 3640 may have an overall length of about 24 mm and an overall width of about 8.6 mm.

[0200] Figure 36D is a simplified bottom view of an example electrode arrangement 3660 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3660 includes a relatively narrow (e.g., about 1.2 mm) outer stadium-shaped electrode 3662, a relatively long (e.g., about 18.2 mm) stadium-shaped inner electrode 3664 having a relatively narrow width (e.g., about 2 mm), and four relatively narrow (e.g., about 0.2 mm) intermediate electrodes 3666, 3668, 3670, 3672 disposed therebetween. In this embodiment, the electrodes 3662, 3664, 3666, 3668, 3670, 3672 may be concentrically arranged, and the spacing between the electrodes 3662, 3664, 3666, 3668, 3670, 3672 may be uniform, about 0.2 mm. The electrode arrangement 3660 may have an overall length of about 24.2 mm and an overall width of about 8 mm.

[0201] Figure 36E is a simplified bottom view of an exemplary electrode arrangement 3680 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3680 includes an outer stadium-shaped electrode 3682 that is relatively wide (e.g., about 1.5 mm), a relatively long (e.g., about 19.6 mm) stadium-shaped inner electrode 3684 having a relatively narrow width (e.g., about 4.5 mm), and two relatively narrow (e.g., about 0.1 mm) intermediate electrodes 3686, 3688 disposed therebetween. In this embodiment, the electrodes 3682, 3684, 3686, 3688 may be concentrically arranged, and the spacing between the electrodes 3682, 3684, 3686, 3688 may be uniform, about 0.2 mm. The electrode arrangement 3680 may have an overall length of about 24 mm and an overall width of about 8.9 mm.

[0202] Figure 36F is a simplified bottom view of an exemplary electrode arrangement 3700 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3700 includes an outer stadium-shaped electrode 3702 that is relatively wide (e.g., about 1 mm), a relatively long (e.g., about 19.2 mm) stadium-shaped inner electrode 3704 having a relatively narrow width (e.g., about 3 mm), and two relatively narrow (e.g., about 0.4 mm) intermediate electrodes 3706, 3708 disposed therebetween. In this embodiment, the electrodes 3702, 3704, 3706, 3708 may be concentrically arranged, and the spacing between the electrodes 3702, 3704, 3706, 3708 may be uniform, about 0.2 mm. The electrode arrangement 3700 may have an overall length of about 24 mm and an overall width of about 7.8 mm.

[0203] Figure 36G is a simplified bottom view of an exemplary electrode arrangement 3720 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3720 includes an outer stadium-shaped electrode 3722 that is relatively wide (e.g., about 2 mm), a relatively long (e.g., about 19.2 mm) stadium-shaped inner electrode 3724 having a relatively narrow width (e.g., about 3 mm), and two relatively narrow (e.g., about 0.4 mm) intermediate electrodes 3726, 3728 disposed therebetween. In this embodiment, the electrodes 3722, 3724, 3726, 3728 may be concentrically arranged, and the spacing between the electrodes 3722, 3724, 3726, 3728 may be uniform, about 0.2 mm. The electrode arrangement 3720 may have an overall length of about 26 mm and an overall width of about 9.8 mm.

[0204] Figure 36HIs a simplified bottom view of an exemplary electrode arrangement 3740 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3740 includes an outer stadium-shaped electrode 3742 that is relatively wide (e.g., about 4 mm), a relatively long (e.g., about 23.6 mm) stadium-shaped inner electrode 3744 having a relatively large width (e.g., about 9 mm), and two relatively wide (e.g., about 3 mm) intermediate electrodes 3746, 3748 disposed therebetween. In this embodiment, the electrodes 3742, 3744, 3746, 3748 may be concentrically arranged, and the spacing between the electrodes 3742, 3744, 3746, 3748 may be uniform, about 0.2 mm. The electrode arrangement 3740 may have an overall length of about 44.8 mm and an overall width of about 21.2 mm.

[0205] Figures 37A to 37D The illustration includes alternative exemplary electrode arrangements of truncated, nested, generally circular (or partially circular) and / or annular (or semi-annular) ring electrodes. These electrode arrangements may be generally similar in structure and operation to other electrode arrangements and related components described herein, and repeated descriptions of similar structures and operations are omitted for the sake of brevity.

[0206] Figure 37A Is a simplified bottom view of an exemplary electrode arrangement 3800 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3800 includes opposite mirror-image segments (e.g., semi-annular segments) of relatively wide (e.g., about 4 mm) outer annular electrodes 3802A, 3802B that are spaced about 5 - 6 mm from a segment of a relatively long (e.g., about 15.6 mm) circular inner electrode 3804, and opposite mirror-image segments (e.g., semi-annular segments) of two relatively narrow (e.g., about 2.5 mm) annular intermediate electrodes 3806A, 3806B, 3808A, 3808B disposed therebetween. The ratio of the surface area of the inner electrode 3804 to the surface areas of the outer electrodes 3802A, 3802B is about 2:1. In this embodiment, the electrodes 3802A, 3802B, 3804, 3806A, 3806B, 3808A, 3808B may be concentrically arranged, and the spacing between the electrodes 3802A, 3802B, 3804, 3806A, 3806B, 3808A, 3808B may be uniform, about 0.2 mm. The electrode arrangement 3800 may have an overall length of about 34.8 mm and a width of about 9 mm.

[0207] Figure 37BIs a simplified bottom view of an example electrode arrangement 3820 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3820 includes opposing mirror-image segments of relatively wide (e.g., about 4 mm) outer annular electrodes 3822A, 3822B spaced apart from a segment of a relatively long (e.g., about 15.6 mm) circular inner electrode 3824 by about 5 - 6 mm and opposing mirror-image segments of two relatively narrow (e.g., about 2.5 mm) annular intermediate electrodes 3826A, 3826B, 3828A, 3828B disposed therebetween. The ratio of the surface area of the inner electrode 3824 to the surface areas of the outer electrodes 3822A, 3822B is about 1.4:1. In this embodiment, the electrodes 3822A, 3822B, 3824, 3826A, 3826B, 3828A, 3828B may be concentrically arranged, and the spacing between the electrodes 3822A, 3822B, 3824, 3826A, 3826B, 3828A, 3828B may be uniform, about 0.2 mm. The electrode arrangement 3820 may have an overall length of about 34.8 mm and a width of about 15 mm.

[0208] Figure 37C Is a simplified bottom view of an example electrode arrangement 3840 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3840 includes opposing mirror-image segments of relatively wide (e.g., about 4 mm) outer annular electrodes 3842A, 3842B, opposing mirror-image segments of a relatively long (e.g., about 15.6 mm) circular inner electrode 3844, and opposing mirror-image segments of two relatively narrow (e.g., about 2.5 mm) annular intermediate electrodes 3846A, 3846B, 3848A, 3848B disposed therebetween. In this embodiment, the electrodes 3842A, 3842B, 3844, 3846A, 3846B, 3848A, 3848B may be concentrically arranged, and the spacing between the electrodes 3842A, 3842B, 3844, 3846A, 3846B, 3848A, 3848B may be uniform, about 0.2 mm. The electrode arrangement 3840 may have an overall length of about 34.8 mm and a width of about 20 mm.

[0209] Figure 37D Is a simplified bottom view of an example electrode arrangement 3860 in accordance with at least some aspects of the present disclosure. As opposed to the embodiments of Figure 37A 、 37B and 37C that are truncated in a generally linear, parallel manner, Figure 37DThe embodiment of [the device] is truncated into a bow shape. That is, the end portions have a greater width than the central portion. In the illustrated embodiment, the electrode arrangement 3860 includes opposite mirror-image segments of relatively wide (e.g., about 4 mm) outer annular electrodes 3862A, 3862B that are spaced about 5 - 6 mm from segments of a relatively long (e.g., about 15.6 mm) circular inner electrode 3864, and opposite mirror-image segments of two relatively narrow (e.g., about 2.5 mm) annular intermediate electrodes 3866A, 3866B, 3868A, 3868B disposed therebetween. The ratio of the surface area of the inner electrode 3864 to the surface areas of the outer electrodes 3862A, 3862B is about 1:1. In this embodiment, the electrodes 3862A, 3862B, 3864, 3866A, 3866B, 3868A, 3868B may be concentrically arranged, and the spacing between the electrodes 3862A, 3862B, 3864, 3866A, 3866B, 3868A, 3868B may be uniform, about 0.2 mm. The electrode arrangement 3860 may have an overall length of about 34.8 mm and an overall width of about 24 mm. The narrower central portion may have a width of about 15 mm.

[0210] Figure 38A is a bottom view of an example electrode arrangement 3880 that includes a semiconductor electrode interposed between two outer electrodes, and Figure 38B is Figure 38A a simplified elevation view of an embodiment of [the device]; all in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, a first outer electrode 3882 and a second outer electrode 3884 are disposed on and in electrical contact with a semiconductor substrate 3886 in a spaced-apart, generally parallel arrangement. Thus, the tissue contact surface 3888 of the electrode arrangement 3880 includes, from one side to the other, the first electrode 3882, the semiconductor substrate 3886, and the second electrode 3884. Although the illustrated embodiment includes two electrodes 3882, 3884, it will be understood that any electrode arrangement described herein may be constructed in a similar manner, where a (plurality of) semiconductor material(s) is disposed in the (plurality of) gap(s) between the electrodes. In the illustrated embodiment, the first outer electrode 3882 includes a first tissue contact location 114A, the semiconductor substrate 3886 includes an intermediate tissue contact location 114B, and the second outer electrode 3884 includes a second tissue contact location 114C.

[0211] Figure 39Is a simplified elevation view of an exemplary electrode arrangement 3900 in accordance with at least some aspects of the present disclosure, the semiconductor electrode including a semiconductor layer disposed on a metal conductor. In the illustrated embodiment, outer conductors 3902, 3904 and intermediate conductors 3906, 3908, 3910, 3912 are arranged in a manner generally similar to the rectangular electrode arrays described elsewhere herein. However, in this embodiment, the conductor array is at least partially covered by a semiconductor layer 3914, which may present a tissue contact surface 3916 and may act as an electrode. For example, the semiconductor layer 3914 may be applied as a coating and / or film, which may be electrically coupled to conductors 3902, 3904, 3906, 3908, 3910, 3912. In the illustrated embodiment, the semiconductor layer 3914 includes a first tissue contact location 114A, an intermediate tissue contact location 114B, and a second tissue contact location 114C.

[0212] Figure 40 Is a simplified elevation view of an exemplary electrode arrangement 4000 in accordance with at least some aspects of the present disclosure, the exemplary electrode arrangement 4000 including a semiconductor electrode in which conductors are embedded. In the illustrated embodiment, first conductor 4002 and second conductor 4004 are arranged in a spaced-apart, generally parallel arrangement generally similar to Figure 38A and Figure 38B the embodiment illustrated in. However, in Figure 40 the embodiment, conductors 4002, 4004 may be embedded within a semiconductor substrate 4006. Accordingly, the tissue contact surface 4008 of the electrode arrangement 4000 includes the semiconductor substrate 4006 that acts as an electrode, while conductors 4002, 4004 are not exposed on the tissue contact surface 4008. In the illustrated embodiment, the semiconductor substrate 4006 includes a first tissue contact location 114A, an intermediate tissue contact location 114B, and a second tissue contact location 114C.

[0213] In some example embodiments including a tissue contact surface including (a) semiconductor material(s), the (a) semiconductor material(s) may be directly electrically connected to one or more conductors configured to deliver ablation energy. In some example embodiments including a tissue contact surface including (a) semiconductor material(s), the (a) semiconductor material(s) may be electrically insulated from at least one conductor configured to deliver ablation energy. In some example embodiments where the tissue contact surface includes (a) semiconductor material(s), the (a) semiconductor material(s) may include one or more gaps or interruptions therein, which may at least partially electrically insulate at least a portion of the semiconductor material from another portion of the semiconductor material. In some example embodiments including a tissue contact surface including (a) semiconductor material(s), the (a) semiconductor material(s) may be uniformly shaped. In some example embodiments including a tissue contact surface including (a) semiconductor material(s), the (a) semiconductor material(s) may be non-uniformly shaped.

[0214] Figure 41 FIG. 4 is a simplified bottom view illustrating a comparison of a symmetric electrode arrangement 5000A and an asymmetric electrode arrangement 5000B. In the illustrated embodiment, each electrode arrangement 5000A, 5000B includes a relatively wide first outer electrode 5004A, 5004B, a relatively wide second outer electrode 5010A, 5010B, and two relatively narrow intermediate electrodes 5006A, 5006B, 5008A, 5008B disposed therebetween. The symmetric arrangement 5000A and the asymmetric arrangement 5000B differ in that the width of the second electrode 5010B is reduced by approximately 20% compared to the second electrode 5010A of the symmetric arrangement 5000A. Similarly, the width of the second intermediate electrode 5008B of the asymmetric arrangement 5000B is reduced by approximately 10% compared to the second intermediate electrode 5008A of the symmetric arrangement 5004A. In this embodiment, the first intermediate electrodes 5006A, 5006B and the first outer electrodes 5004A, 5004B are substantially the same in the symmetric arrangement 5000A and the asymmetric arrangement 5000B. Generally, the asymmetric arrangement 5000B will produce an asymmetric ablation, with hotter ablation near the narrower electrodes. Such an embodiment may be used, for example, to target specific anatomical features and / or to reduce heating at one end relative to the other end. Similar asymmetries may be utilized in conjunction with any of the embodiments described herein, including rectangular arrays, concentric arrays, etc.

[0215] Figure 42It is a simplified bottom view showing the dimensions of the variable rectangular electrode array 5050. In the illustrated embodiment, the electrode arrangement 5050 includes relatively wide outer electrodes 5052, 5054 and four relatively narrow intermediate electrodes 5056, 5058, 5060, 5062 disposed therebetween. The outer electrodes 5052, 5054 have a width 5064 and are spaced apart by a gap 5066. The array 5050 has a length 5068.

[0216] In some example embodiments, the outer electrode width can be about 2 - 6 mm. In some configurations, an outer electrode width greater than about 8 mm can result in an overly low current density at the electrode, which may produce weak ablation. In some configurations, an outer electrode width less than about 2 mm can result in an overly high current density at the electrode, which may produce overly strong ablation.

[0217] In some example embodiments, such as those having an outer electrode width of about 2 - 6 mm, the gap 5066 can be about 2 - 8 mm. In some configurations, an overly narrow gap can result in an excessive current density and / or overheating at the center between the electrodes. An overly wide gap can result in a bimodal current density and / or underheating at the center between the electrodes.

[0218] Generally, the presence of the intermediate electrodes 5056, 5058, 5060, 5062 reduces the current density near the tissue surface, which reduces overheating near the tissue surface. Generally, the length 5068 can be arbitrarily changed; however, it may be advantageous to adjust the power density accordingly.

[0219] Figure 43 It is a simplified bottom view showing the dimensions of the variable concentric electrode array 6000. In the illustrated embodiment, the electrode arrangement 6000 includes opposing mirror image segments of relatively wide outer annular electrodes 6002A, 6002B, segments of a relatively wide circular inner electrode 6004, and opposing mirror image segments of two relatively narrow annular intermediate electrodes 6006A, 6006B, 6008A, 6008B disposed therebetween. The outer electrodes 6002A, 6002B have a width 6010 and are spaced apart by a gap 6012. The array 6000 has a length 6014. The width 6010 and the gap 6012 can generally vary as described above with reference to the rectangular electrode arrangement 5050.

[0220] Generally, the presence of the intermediate electrodes 6006A, 6006B, 6008A, 6008B tends to increase the effective depth of ablation, such as due to the concentrated current density near the central region. Generally, the length 6014 can be arbitrarily changed; however, it may be advantageous to adjust the power density accordingly.

[0221] In some example embodiments, the power density of the ablative energy applied may be selected to produce consistent ablation. As used herein, "power density" may refer to the ratio of the power applied to the surface area of the outermost electrode. For example, a power density of less than about 0.05 watts per square millimeter may generally heat the target tissue more slowly than desired. A power density of about 0.05 - 0.5 watts per square millimeter may generally produce the desired ablation results. A power density greater than about 0.5 watts per square millimeter may generally overheat the target tissue.

[0222] In some example embodiments, such as an embodiment having an inner electrode 6004 and two outer electrodes 6002A, 6002B, the ratio of the surface area of the inner electrode 6004 to the surface areas of the outer electrodes 6002A, 6002B may be from about 0.3:1 to about 3:1. In some configurations, a ratio less than about 0.3:1 may tend to concentrate the ablative energy at the inner electrode. In some configurations, a ratio greater than about 3:1 may concentrate the ablative energy at the outer electrodes.

[0223] Referring back to Figures 1A to 1E , an example method of forming an ablation lesion 118 in the target tissue 116 may include one or more of the following operations in any order. The tissue engagement portion 114 of the end effector 102 of the ablation device 100 may be positioned in proximity to the target tissue 116 such that a first tissue contact location 114A of the tissue engagement portion 114 is in electrical contact with the target tissue 116, a middle tissue contact location 114B of the tissue engagement portion 114 is in electrical contact with the target tissue 116, and a second tissue contact location 114C is in electrical contact with the target tissue 116. By applying electroablative energy to the end effector 102 such that the magnitude of at least one electrical parameter is different between the first tissue contact location 114A, the middle tissue contact location 114B, and the second tissue contact location 114C, with the magnitude at the middle tissue contact location being between the magnitudes at the first and second tissue contact locations, an ablation lesion 118 may be formed in the target tissue 116.

[0224] In some embodiments, electroablation energy may be applied to a discrete first electrode 110a including a first tissue contact location 114A and a discrete second electrode 110f including a second tissue contact location 114C. In some embodiments, electroablation energy may be applied to discrete intermediate electrodes 110b, 110c, 110d, 110e including an intermediate tissue contact location 114B. In some embodiments, the intermediate electrodes 110b, 110c, 110d, 110e may include at least two discrete intermediate electrodes 110b, 110c, 110d, 110e disposed in sequence, and electroablation energy may be applied to the at least two discrete intermediate electrodes 110b, 110c, 110d, 110e disposed in sequence such that the magnitude of at least one electrical parameter varies incrementally between the at least two discrete intermediate electrodes 110b, 110c, 110d, 110e.

[0225] In some embodiments, such as in Figure 38A and Figure 38B electroablation energy may be applied to a semiconductor element 3886 including an intermediate tissue contact location.

[0226] In some embodiments, such as in Figure 40 electroablation energy may be applied from an ablation energy source to a first electrical conductor 4002 and a second electrical conductor 4004, wherein the first electrical conductor 4002 is electrically coupled to a semiconductor element 4006 near the first tissue contact location 114A, and the second electrical conductor 4004 is electrically coupled to the semiconductor element 4006 near the second tissue contact location 114C.

[0227] In some embodiments, such as in Figure 39 electroablation energy may be applied to intermediate electrical conductors 3906, 3908, 3910, 3912 that are electrically coupled to a semiconductor element 3914 near the intermediate tissue contact location 114B. The magnitude of at least one electrical parameter may vary between the first electrical conductor 3902, the intermediate electrical conductors 3906, 3908, 3910, 3912, and the second electrical conductor 3904 such that the magnitude at the intermediate tissue contact location is between the magnitude at the first tissue contact location and the magnitude at the second tissue contact location.

[0228] In some embodiments, electroablation energy may be applied to the intermediate electrical conductor via a first resistor R1 from an ablation source and via a second resistor R5 from the second electrical conductor.

[0229] In some embodiments, electroablation energy may be applied to a discrete first electrode 110a including a first tissue contact location 114A and a discrete second electrode 110f including a second tissue contact location 114C.

[0230] In some embodiments, at least one electrical parameter may include potential and / or current. In some embodiments, electroablation energy may include radiofrequency energy and / or pulsed field ablation energy.

[0231] In some embodiments, ablation device 100 may include a shaft 104 disposed proximally on end effector 102, and tissue engaging portion 114 of end effector 102 of ablation device 100 may be positioned using shaft 104. In some embodiments, ablation device 100 may include a handle 106 disposed proximally on shaft 104, and tissue engaging portion 114 of end effector 102 of ablation device 100 may be positioned using handle 106. In some example embodiments, ablation device may include at least one connection element 108 configured to electrically couple end effector 102 to an external ablation energy source, and electroablation energy may be applied to end effector 102 via at least one connection element 108.

[0232] Some example embodiments constructed for ablation of cardiac tissue in accordance with at least some aspects of the present disclosure may be configured to ablate target tissue to a depth greater than about 5.0 mm, such as a depth of 5.0 - 10.0 mm.

[0233] Example embodiments including a first electrode, a second electrode, and four intermediate electrodes may operate at about 30 to 80 V (maximum potential between the first and second electrodes), about 300 to 500 kHz, and / or about 15 to 40 watts.

[0234] An example procedure for forming an ablation lesion with a depth between 3 mm and 15 mm will involve firmly touching the cardiac tissue with the smaller electrode arrangement of Figure 10 、 Figure 11 or Figure 12 activating the source for a duration of 20 to 90 seconds under the conditions noted in the previous paragraph, and then turning off the source and removing the electrode. A second example procedure for forming an ablation lesion with a depth between 3 mm and 15 mm will involve firmly touching the cardiac tissue with the larger electrode arrangement of Figure 13A 、 Figure 13B or Figure 14 activating the source for a duration of 40 to 300 seconds under the conditions noted in the previous paragraph, and then turning off the source and removing the electrode.

[0235] In various example embodiments in accordance with at least some aspects of the present disclosure, the device may be configured to deliver energy to the target tissue in a cautery mode, a microwave mode, a pulsed field ablation mode, or a radiofrequency mode, or any combination of any one or more of these modes. Example radiofrequency modes include bipolar, monopolar, and / or multipolar modes. In these cases, the voltage, current, power, and frequency may be different from those noted elsewhere in the present disclosure.

[0236] Some example embodiments according to at least some aspects of the present disclosure may be configured for operations other than and / or in addition to tissue ablation, such as test operations. For example but not limited to, some embodiments may be configured for cardiac pacing and / or sensing and / or for electroporation, such as over a relatively large area for drug delivery. Some non-ablation operations may be performed in combination with ablation operations, such as to evaluate the need for, location of, and / or efficacy of one or more ablations. Additionally, some ablation operations may be performed in combination with non-ablation operations, such as cut-ablation operations, clamp-ablation operations, and / or cryogenic treatment and ablation operations.

[0237] Although some example embodiments have been described above in the context of ablation of cardiac tissue, it will be understood that some alternative example embodiments may be used in conjunction with other target tissues and anatomical locations. For example but not limited to, some alternative example embodiments may be configured for use in conjunction with target tissues associated with a patient's brain, gastrointestinal organs, lungs, liver, skin, gynecological organs, esophageal tissue, and / or tissue associated with the mouth and / or nose.

[0238] Performing an electro-surgical (e.g., ablation) procedure using any suitable electrode is within the scope of the present disclosure. For example but not limited to, suitable electrode geometries may include rectangular configurations (e.g., generally parallel to the end effector and / or generally transverse to the end effector) and / or non-rectangular configurations (e.g., rings, concentric arrangements, bull's-eye configurations, generally circular arrangements, and / or generally elliptical arrangements), or any combination thereof (e.g., one or more lines within an ellipse). In some example embodiments, one or more electrodes may have a three-dimensional configuration, such as cup-shaped, dome-shaped, a configuration generally conforming to an anatomical structure, and / or a custom-fit configuration for a particular anatomical structure. Other configurations may include a tiled matrix, a generally flat configuration in a plane, and / or a generally flat configuration out of a plane. Some example electrodes may be in the form of discrete electrodes. Some example electrodes may be in the form of continuous electrodes, such as semiconductor electrodes, thin film conductors with various applied voltages, and / or conductive fluids.

[0239] Some example embodiments according to at least some aspects of the present disclosure may be configured to simultaneously control multiple variables in order to achieve desired performance during operation, where such coupled variables may include, for example, functions of the following parameters varying over time: electrode power, applied pressure of an inflatable device, applied vacuum of a suction device, and / or temperature generated by ablation or from a secondary heating or cooling source.

[0240] Some example embodiments according to at least some aspects of the present disclosure can be configured to address thermal issues associated with operation. For example, some embodiments can be configured to actively and / or passively remove excess heat, and / or can be controlled to operate at a desired temperature. Some example embodiments can include cooling elements, such as heat pipes, which can be disposed near the electrodes, such as between the electrodes. Some example embodiments can utilize system-level cooling, such as cooling water pumped around and / or through the electrodes and / or tissue contact surfaces. Some example embodiments can utilize electrode-level cooling, such as cooling water pumped behind the electrodes. Some example embodiments can utilize passive cooling, such as one or more heat sinks disposed behind the electrodes. Some example embodiments can include more than two electrodes configured for cooperative operation. For example, any number of electrodes can be configured for a phased group / switching group.

[0241] Controlling the electrical parameters associated with individual electrodes in any suitable manner is within the scope of the present disclosure. For example but not limited to, various devices according to at least some aspects of the present disclosure can be configured to deliver electrical energy to one or more electrodes at a selected potential (voltage), current, and / or power. In some example embodiments, some electrical parameters can be configured for passive control, such as by using resistor banks (e.g., resistive voltage dividers), capacitor banks, and / or inductor banks. In some example embodiments, some electrical parameters can be configured for active control, such as individual electrode control, switch box configuration (e.g., one generator powering multiple electrodes through active switching), multiple generators, and / or active monitoring and parameter adjustment. Some example embodiments can include control arrangements that utilize feedback (such as feedback regarding current, power, impedance, inductance, capacitance, temperature (e.g., tissue temperature), and / or time).

[0242] Although specific example embodiments have been described above, constructing the device in various alternative forms is also within the scope of the present disclosure. For example but not limited to, some example devices can include extensible, flexible (e.g., flexing in one plane, flexing in two planes, etc.), and / or rigid elements. Some example devices can include elements configured for rolling and / or folding, such as rolling along a short axis and / or rolling along a long axis.

[0243] Utilizing various fixation methods in conjunction with example embodiments is within the scope of the present disclosure. For example but not limited to, some example devices can be configured to use manual fixation (e.g., mechanical load applied by an operator), vacuum fixation, clamping, and / or magnetic coupling to hold the end effector against the target tissue. See, for example, the description above with reference to FIGS. 2 and 3.

[0244] End effectors having various shapes are within the scope of the present disclosure. For example but not limited to, some example end effectors may be contoured and / or may include electrodes disposed generally on the inner and / or outer sides. In some example embodiments, the electrodes may be generally circular, annular, provided as a sheath or collar, generally tubular or cylindrical (e.g., full radius and / or partial radius).

[0245] End effectors including inflatable elements are within the scope of the present disclosure. In some example embodiments, components including inflatable elements may be configured to conform to adjacent structures (e.g., anatomical structures). In some example embodiments, components including inflatable elements may be configured to have a predetermined, generally fixed shape. See, for example, the description above with reference to Figure 4 , Figure 19 and Figure 23 the description.

[0246] Procedures involving any suitable access route are within the scope of the present disclosure. For example, percutaneous access routes (e.g., arterial and / or venous) and / or surgical access routes (e.g., transapical, femoral-femoral bypass (venous), femoral-femoral bypass (arterial), conventional bypass cannulation (arterial), conventional bypass cannulation (venous), and / or atriotomy) may be used to obtain endocardial access. Percutaneous access routes (e.g., subxiphoid) and / or surgical access routes (e.g., lateral (right or left), surgical fenestration, and / or sternotomy (total or partial)) and / or minimally invasive surgical (MIS) access routes may be used to obtain epicardial access. It will be understood that the foregoing listing is merely exemplary and should not be considered limiting.

[0247] Procedures involving any part of the heart using the devices and / or methods disclosed herein are within the scope of the present disclosure. For example, procedures involving the right atrium can be performed in conjunction with the treatment of inappropriate sinus tachycardia (e.g., crista terminalis line, inferior vena cava, and / or superior vena cava), atrial fibrillation (e.g., Cox maze lesion - right side), supraventricular tachycardia, and / or Wolff-Parkinson-White syndrome. Procedures involving the right ventricle can be performed in conjunction with, for example, the treatment of ventricular tachycardia (e.g., linear or spot lesions) (e.g., posterior wall of the right ventricle, lateral free wall of the right ventricle, anterior right ventricle, interventricular septum, papillary muscle of the right ventricle, and / or right ventricular outflow tract), partial ventricular contraction (e.g., right ventricular outflow tract septum, basal right ventricle, and / or free wall of the right ventricular outflow tract), and / or Brugada syndrome (e.g., right ventricular outflow tract). Procedures involving the left atrium can be performed in conjunction with the treatment of atrial fibrillation (e.g., circumferential or linear lesions) (e.g., ligament of Marshall, roof line and floor line, posterior wall of the left atrium, isthmus line, and / or autonomic (ganglionated plexi)), supraventricular tachycardia, and / or left atrial appendage isolation (e.g., left atrial appendage ostium). Procedures involving the left ventricle can be performed in conjunction with, for example, syncope (e.g., autonomic (ganglionated plexi)), atrial tachycardia (e.g., at any location in the left ventricle), atrial flutter (e.g., mitral valve), Wolff-Parkinson-White syndrome (e.g., atrioventricular groove), partial ventricular contraction (e.g., left ventricular outflow tract and / or aortic root), hypertension (e.g., at any location in the left ventricle), Brugada, and / or ventricular tachycardia (e.g., linear or spot lesions) (e.g., posterior wall of the left ventricle, lateral free wall of the left ventricle, anterior left ventricle, interventricular septum, papillary muscle of the left ventricle, and / or apex of the left ventricle). Procedures involving the right ventricle / left ventricle septum can be performed in conjunction with, for example, ventricular tachycardia (e.g., combined right ventricle and left ventricle lesions). Some procedures involving the right atrium / left atrium septum can be performed. It will be understood that the foregoing listing is merely exemplary and should not be considered limiting.

[0248] The present disclosure contemplates that ablation systems configured to perform pulsed field ablation ("PFA") can be used in a variety of medical and surgical procedures. Generally, a PFA system can be used to ablate targeted cells while limiting potential collateral damage to non-target tissue. PFA typically involves applying high voltage electrical pulses to the target tissue. The pulses generate high intensity electric fields that disrupt the integrity of cell membranes in the target tissue. As a result, within a short period of time (e.g., days to weeks), cell death occurs, creating a lesion in the target tissue. The present disclosure contemplates that PFA can be used to ablate cardiac tissue for the treatment of arrhythmias. Generally, any ablation device according to at least some aspects of the present disclosure can be utilized in combination with radiofrequency, pulsed field ablation, and / or any other electrical ablation modality.

[0249] Some example embodiments in accordance with at least some aspects of the present disclosure may be configured without a heat sink and / or without active cooling (e.g., open or closed loop liquid cooling). Some example embodiments (such as those configured for bipolar operation) may be configured without a monopolar ground (e.g., return electrode).

[0250] As used herein, including in the claims, the "or" used in a list of items (e.g., a list of items beginning with a phrase such as "at least one of... " or "one or more of... ") indicates an inclusive list, such that a list of (e.g., at least one of A, B, or C) means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

[0251] As will now be appreciated by those skilled in the art and depending on the current particular application, many modifications, substitutions, and variations may be made in and to the materials, apparatus, construction, and methods of use of the devices of the present disclosure without departing from the spirit and scope of the present disclosure. In view of this, the scope of the present disclosure should not be limited to the scope of the specific embodiments illustrated and described herein, as they are merely some examples thereof, but rather should be fully commensurate with the scope of the appended claims and their functional equivalents.

Claims

1. An ablation device for use with an energy source to apply energy to tissue, the ablation device comprising: An end effector having a working surface; A connector configured to electrically couple the energy source to the end effector; And A plurality of electrodes in electrical communication with the working surface and configured to apply energy from the energy source to the tissue, wherein the plurality of electrodes include a first electrode and a second electrode on opposite sides of one or more intermediate electrodes, and wherein during application of the energy, the plurality of electrodes are configured such that the first electrode delivers a first voltage and the second electrode delivers a second voltage, and wherein each of the one or more intermediate electrodes delivers an intermediate voltage, and wherein the voltage potential difference between the first voltage and the second voltage is greater than the voltage potential difference between the first electrode and the intermediate voltage of any one of the one or more intermediate electrodes, such that the tissue is ablated while also restricting thermal changes within the tissue and locations at the tissue surface where the surface temperature exceeds a maximum temperature.

2. The tissue ablation device according to claim 1, wherein, The end effector includes a radiofrequency pen.

3. The tissue ablation device according to claim 1, wherein, The end effector includes a radiofrequency clamp.

4. The tissue ablation device according to claim 1, wherein The end effector includes a radiofrequency pen or a radiofrequency cannula, the radiofrequency pen or radiofrequency cannula including vacuum aspiration.

5. The tissue ablation device according to claim 1, wherein, The end effector includes an expandable device.

6. The tissue ablation device according to claim 5, wherein, The expandable device includes an inflatable element.

7. The tissue ablation device according to claim 1, wherein, The first electrode and the second electrode have a greater width than the intermediate electrodes.

8. The tissue ablation device according to claim 7, wherein, The first electrode and the second electrode have a width of 2 to 8 mm, the intermediate electrodes have a width less than the first electrode and the second electrode, and the total width including the maximum voltage potential difference is between 10 and 30 mm.

9. The tissue ablation device according to claim 8, wherein, The length of the plurality of electrodes is configured to produce a desired ablation length.

10. The tissue ablation device according to claim 1, wherein, The plurality of electrodes includes three or more electrodes.

11. The tissue ablation device according to claim 1, wherein, The plurality of electrodes are distributed in a rectangular array.

12. The tissue ablation device according to claim 1, wherein, The first electrode, the second electrode, and the intermediate electrodes are distributed annularly, with each electrode being concentric with adjacent electrodes.

13. The tissue ablation device according to claim 1, wherein, The power of each electrode is different from that of adjacent electrodes.

14. The tissue ablation device according to claim 1, wherein, The current of each electrode is different from that of adjacent electrodes.

15. The tissue ablation device according to claim 1, wherein, The intermediate electrode includes a resistive conductor, wherein the resistive conductor is configured to reduce the potential difference between the first electrode and the second electrode.

16. The tissue ablation device according to claim 1, wherein, The voltage potential difference between each adjacent electrode is uniform or non-uniform.

17. The tissue ablation device according to claim 1, wherein, The maximum voltage potential difference is between 10 volts and 500 volts.

18. The tissue ablation device according to claim 17, wherein, The maximum voltage potential difference is between 30 volts and 80 volts.

19. The tissue ablation device according to claim 1, wherein, The total power output is between 1 watt and 200 watts.

20. The tissue ablation device according to claim 19, wherein, The total power output is between 10 watts and 40 watts.

21. The tissue ablation device according to claim 1, wherein The applied frequency is between 50 kilohertz and 5000 kilohertz.

22. The tissue ablation device according to claim 21, wherein, The applied frequency is between 300 and 500 kilohertz.

23. The electrode array according to claim 1, wherein, A plurality of electrode arrays are located end-to-end on the tissue ablation device to extend the surface length of the ablation region while maintaining the electrical and thermal energy within the width and depth of the ablation region.

24. The tissue ablation device according to claim 1, wherein, The voltage and current of each electrode are in phase or out of phase with adjacent electrodes, wherein the phase is the time-dependent phase of the applied AC voltage potential.

25. The tissue ablation device according to claim 1, wherein, The voltage and current of each of the first electrode and the second electrode are sinusoidal waves that vary with time.

26. The tissue ablation device according to claim 1, wherein, The voltage and current of each of the first electrode and the second electrode are rectangular waves that vary with time.

27. The tissue ablation device according to claim 1, wherein, The intermediate electrode is electrically disconnected from the first electrode and the second electrode, wherein the intermediate electrode conducts current and reduces the resistance between the first electrode and the second electrode.

28. A tissue ablation device for ablating tissue, the device comprising: An end effector having a tissue contact surface; A power source coupled to the end effector; And An array of electrodes in electrical communication with the tissue contact surface, wherein each electrode in the array of electrodes is maintained at a voltage potential, current, or power provided from the voltage source, wherein the voltage potential, current, or power of each electrode is different from that of an adjacent electrode, and wherein the array of electrodes is configured to ablate the tissue while distributing the potential across the surface of the tissue such that the distribution of the potential reduces temperature variations within the ablated tissue.

29. A method for ablating tissue, the method comprising: Positioning an end effector at a target site of the tissue, wherein the end effector includes a tissue contact surface in electrical communication with an array of electrodes; Applying a voltage potential, current, or power from a power source to each electrode in the array of electrodes, wherein the array of electrodes includes a distributed potential and is configured to ablate the tissue while distributing the potential across the tissue; and Ablating the tissue spaced apart from the end effector while minimizing the heat applied to the surface of the tissue to produce a more uniform and deeper ablation.

30. An electrosurgical device, comprising: A first electrode; A second electrode; And An intermediate electrical element; Wherein the first electrode, the second electrode, and the intermediate electrical element are configured to be in electrical communication with target tissue; and Wherein the intermediate electrical element is interposed between the first electrode and the second electrode.

31. The electrosurgical device according to claim 30, wherein, The intermediate electrical element includes at least one intermediate electrode.

32. The electrosurgical device according to claim 31, wherein, The at least one intermediate electrode includes a plurality of intermediate electrodes.

33. The electrosurgical device according to claim 31, Among them, The first electrode, the at least one intermediate electrode, and the second electrode are configured to deliver electrical energy to the target tissue; And Wherein at least one electrical parameter of the electrical energy varies incrementally between the first electrode, the at least one intermediate electrode, and the second electrode.

34. The electrosurgical device according to claim 33, wherein, The at least one electrical parameter includes potential.

35. The electrosurgical device according to claim 33, wherein, The at least one electrical parameter includes power.

36. The electrosurgical device according to claim 33, wherein, The at least one electrical parameter includes current.

37. An electrosurgical system, comprising: The electrosurgical device according to claim 30; And A resistive voltage divider electrically connected to a first input conductor and a second input conductor, the resistive voltage divider including a first resistor and a second resistor; Wherein the first resistor and the second resistor are electrically connected in series between the first input conductor and the second input conductor; and Wherein, the first electrode is configured to be electrically connected to the first input connector, the second electrode is configured to be electrically connected to the second input connector, and the at least one intermediate electrode is configured to be electrically connected to at least one intermediate conductor, and the at least one intermediate conductor is electrically connected between the first resistor and the second resistor.

38. The electrosurgical system according to claim 37, Among them, The resistive voltage divider is disposed in at least one of a handle, a shaft, an end effector, or a connecting element of the electrosurgical device; Wherein, the first input conductor and the second input conductor are configured to be releasably electrically coupled to an electrosurgical generator; wherein, the first input conductor is electrically coupled to the first electrode; Wherein, the second input conductor is electrically coupled to the second electrode; and Wherein, the at least one intermediate electrode is electrically coupled to the at least one intermediate conductor.

39. The electrosurgical system according to claim 37, Among them, The resistive voltage divider is disposed in an interface component configured to be electrically interposed between the electrosurgical device and the electrosurgical generator; Wherein, the first input conductor and the second input conductor are configured to be releasably electrically coupled to an electrosurgical generator; Wherein, the first input conductor is configured to be releasably electrically coupled to the first electrode; Wherein, the second input conductor is configured to be releasably electrically coupled to the second electrode; and Wherein, the at least one intermediate conductor is configured to be releasably electrically coupled to the at least one intermediate electrode.

40. The electrosurgical system according to claim 38, Among them, The resistive voltage divider is disposed in the electrosurgical generator; Wherein, the first input conductor is configured to be releasably electrically coupled to the first electrode; Wherein, the second input conductor is configured to be releasably electrically coupled to the second electrode; and Wherein, the at least one intermediate conductor is configured to be releasably electrically coupled to the at least one intermediate electrode.

41. An electrosurgical device, comprising: A first electrode; A second electrode; And At least one intermediate resistive element; Wherein, the first electrode, the second electrode, and the at least one intermediate resistive element are configured to be in electrical communication with a target tissue; and Wherein, the at least one intermediate resistive element is interposed between the first electrode and the second electrode.

42. The electrosurgical device according to claim 41, Among them, The at least one intermediate resistive element includes a first resistive element electrically connected to the first electrode and a second resistive element electrically connected to the second electrode; And Wherein, the first resistive element is not directly electrically connected to the second resistive element.

43. The electrosurgical device according to claim 42, wherein, The first resistive element and the second resistive element are interposed by a gap therebetween.

44. The electrosurgical device according to claim 43, wherein, The gap includes at least one of an unoccupied space and a non-conductive element.

45. The electrosurgical device according to claim 41, wherein, The at least one intermediate resistive element is electrically connected between the first electrode and the second electrode.

46. The electrosurgical device according to claim 41, wherein, The resistance of the at least one intermediate resistive element is approximately equal to the resistance of the target tissue.

47. An electrosurgical device, comprising: A tissue contact surface that is in electrical communication with a first electrode, a second electrode, and a plurality of intermediate electrodes; And An electrical input connector; Wherein, the first electrode and the second electrode are spaced apart by a first width; Wherein, the plurality of intermediate electrodes are sequentially arranged between the first electrode and the second electrode along the first width; and Wherein, at least one electrical parameter varies between the first electrode, the plurality of intermediate electrodes, and the second electrode such that the electrical parameter has a first value at the first electrode, a second value at the second electrode, and a corresponding intermediate value between the first value and the second value at each of the intermediate electrodes.

48. The electrosurgical device according to claim 47, wherein, The intermediate values vary incrementally between the first electrode, each intermediate electrode, and the second electrode.

49. An ablation device for forming an ablation lesion in target tissue, the ablation device comprising: An end effector, the end effector comprising A tissue engaging portion configured to engage the target tissue, the tissue engaging portion configured for electrical contact with the target tissue and comprising a first tissue contact portion, a second tissue contact portion, and an intermediate tissue contact portion; Wherein, the intermediate tissue contact portion is disposed between the first tissue contact portion and the second tissue contact portion; and Wherein, the first tissue contact portion, the intermediate tissue contact portion, and the second tissue contact portion are electrically coupled such that when the end effector is supplied with electro-ablation energy, the magnitude of at least one electrical parameter is different between the first tissue contact portion, the intermediate tissue contact portion, and the second tissue contact portion, such that the magnitude of the intermediate tissue contact portion is between the magnitude of the first tissue contact portion and the magnitude of the second tissue contact portion.

50. The ablation device according to claim 49, wherein, The tissue engaging portion includes a discrete first electrode and a discrete second electrode, the discrete first electrode including the first tissue contact portion, and the discrete second electrode including the second tissue contact portion.

51. The ablation device according to claim 50, wherein, The tissue engaging portion includes discrete intermediate electrodes, the discrete intermediate electrodes including the intermediate tissue contact portion.

52. The ablation device according to claim 51, wherein, The tissue engaging portion includes a first insulator between the first electrode and the intermediate electrode and a second insulator between the intermediate electrode and the second electrode.

53. The ablation device according to claim 51, Among them, The intermediate electrode includes at least two discrete intermediate electrodes sequentially arranged; and Wherein, the magnitude of the at least one electrical parameter is incrementally different between the at least two discrete intermediate electrodes sequentially arranged.

54. The ablation device according to claim 51, Among them, The first electrode, the intermediate electrode, and the second electrode are arranged in a line; and Wherein, the first electrode is arranged as a first outermost electrode at a first end, and the second electrode is arranged as a second outermost electrode at a second end.

55. The ablation device according to claim 51, wherein, The first electrode is nested within the intermediate electrode, and the intermediate electrode is nested within the second electrode.

56. The ablation device according to claim 55, wherein, The first electrode is concentrically nested within the intermediate electrode, and the intermediate electrode is concentrically nested within the second electrode.

57. The ablation device according to claim 51, wherein, The intermediate electrode and the second electrode include nested, concentric, generally stadium-shaped ring electrodes disposed around the first electrode.

58. The ablation device according to claim 51, wherein, The first electrode is generally circular, the intermediate electrode is generally semi-circular and is disposed around the first electrode, and the second electrode is generally semi-circular and is disposed around the intermediate electrode.

59. The ablation device according to claim 58, wherein, The first electrode, the intermediate electrode, and the second electrode vary in at least one of width and length, wherein at least one of the first electrode, the intermediate electrode, and the second electrode is divisible into a plurality of segments.

60. The ablation device according to claim 58, wherein, At least two of the first electrode, the intermediate electrode, and the second electrode are truncated to form a generally bowtie shape.

61. The ablation device according to claim 49, wherein, The tissue engaging portion includes a semiconductor element, and the semiconductor element includes the intermediate tissue contact portion.

62. The ablation device according to claim 61, wherein, The semiconductor element has a resistivity greater than that of the target tissue.

63. The ablation device according to claim 61, wherein, The semiconductor element further includes the first tissue contact portion and the second tissue contact portion.

64. The ablation device according to claim 63, Among them, The end effector further includes a first electrical conductor that is electrically coupled to the semiconductor element near the first tissue contact portion; wherein the end effector further includes a second electrical conductor that is electrically coupled to the semiconductor element near the second tissue contact portion; and wherein the first electrical conductor and the second electrical conductor are configured to receive the electroablation energy from an ablation energy source.

65. The ablation device according to claim 61, wherein, The end effector further includes an intermediate electrical conductor that is electrically coupled to the semiconductor element near the intermediate tissue contact portion.

66. The ablation device according to claim 65, wherein, The intermediate electrical conductor is electrically coupled to the first electrical conductor and the second electrical conductor such that when the first electrical conductor and the second electrical conductor are supplied with electroablation energy, the magnitude of at least one electrical parameter is different between the first electrical conductor, the intermediate electrical conductor, and the second electrical conductor, such that the magnitude of the intermediate tissue contact portion is between the magnitude of the first tissue contact portion and the magnitude of the second tissue contact portion.

67. The ablation device according to claim 66, Among them, The intermediate electrical conductor is electrically coupled to the first electrical conductor by a first resistor; and wherein the intermediate electrical conductor is electrically coupled to the second electrical conductor by a second resistor.

68. The ablation device according to claim 61, wherein, The tissue engaging portion includes a discrete first electrode and a discrete second electrode, the discrete first electrode includes the first tissue contact portion, and the discrete second electrode includes the second tissue contact portion.

69. The ablation device according to claim 68, wherein, The semiconductor element is electrically coupled to the first electrode and the second electrode.

70. The ablation device according to claim 49, wherein, The at least one electrical parameter includes potential.

71. The ablation device according to claim 49, wherein The at least one electrical parameter includes current.

72. The ablation device according to claim 49, wherein, The electroablation energy includes radiofrequency electrical energy.

73. The ablation device according to claim 49, wherein, The electroablation energy includes pulsed field ablation electrical energy.

74. The ablation device according to claim 49, further comprising a shaft disposed proximally on the end effector.

75. The ablation device according to claim 74, further comprising a handle disposed proximally on the shaft.

76. The ablation device according to claim 49, further comprising at least one connection element configured to electrically couple the end effector to an external ablation energy source.

77. A method of forming an ablation lesion in a target tissue, the method comprising: Positioning a tissue engaging portion of an end effector of an ablation device adjacent to the target tissue such that a first tissue contacting portion of the tissue engaging portion is in electrical contact with the target tissue, a second tissue contacting portion of the tissue engaging portion is in electrical contact with the target tissue, and an intermediate tissue contacting portion of the tissue engaging portion between the first tissue contacting portion and the second tissue contacting portion is in electrical contact with the target tissue; Forming an ablation lesion in the target tissue by applying electroablation energy to the end effector such that a magnitude of at least one electrical parameter is different between the first tissue contacting portion, the intermediate tissue contacting portion, and the second tissue contacting portion, such that the magnitude at the intermediate tissue contacting portion is less than the magnitude at the first tissue contacting portion and greater than the magnitude at the second tissue contacting portion.

78. The method according to claim 77, wherein Applying the electroablation energy to the end effector includes applying the electroablation energy to a discrete first electrode including the first tissue contacting portion and a discrete second electrode including the second tissue contacting portion.

79. The method according to claim 78, wherein, Applying the electroablation energy to the end effector includes applying the electroablation energy to a discrete intermediate electrode including the intermediate tissue contacting portion.

80. The method according to claim 79, Among them, The intermediate electrode includes at least two discrete intermediate electrodes arranged in sequence; and wherein applying the electroablation energy to the discrete intermediate electrodes includes applying the electroablation energy to the at least two discrete intermediate electrodes arranged in sequence such that the magnitude of the at least one electrical parameter is incrementally different between the at least two discrete intermediate electrodes arranged in sequence.

81. The method according to claim 49, wherein Applying the electroablation energy to the end effector includes applying the electroablation energy to a semiconductor element including the intermediate tissue contacting portion.

82. The method according to claim 81, wherein, Applying the electroablation energy to the end effector includes applying the electroablation energy to the semiconductor element, the semiconductor element further including the first tissue contacting portion and the second tissue contacting portion.

83. The method according to claim 82, Among them, Applying the electroablation energy to the end effector includes applying the electroablation energy from an ablation energy source to a first electrical conductor and a second electrical conductor; wherein the first electrical conductor is electrically coupled to the semiconductor element adjacent to the first tissue contacting portion; and wherein the second electrical conductor is electrically coupled to the semiconductor element adjacent to the second tissue contacting portion.

84. The method according to claim 81, Among them, Applying the electroablation energy to the end effector includes applying the electroablation energy from the ablation energy source to an intermediate electrical conductor; wherein the intermediate electrical conductor is electrically coupled to the semiconductor element adjacent to the intermediate tissue contacting portion.

85. The method according to claim 84, wherein, Applying the electro-ablation energy from the ablation energy source to the intermediate electrical conductor includes applying the electro-ablation energy from the ablation source to the intermediate electrical conductor such that the magnitude of at least one electrical parameter is different between the first electrical conductor, the intermediate electrical conductor, and the second electrical conductor, and such that the magnitude of the intermediate tissue contact portion is between the magnitude of the first tissue contact portion and the magnitude of the second tissue contact portion.

86. The method according to claim 85, wherein Applying the electro-ablation energy from the ablation source to the intermediate electrical conductor includes applying the electro-ablation energy from the ablation source to the intermediate electrical conductor from the first electrical conductor via a first resistor and from the second electrical conductor via a second resistor.

87. The method according to claim 81, wherein Applying electro-ablation energy to the end effector includes applying the electro-ablation energy to a discrete first electrode including the first tissue contact portion and a discrete second electrode including the second tissue contact portion.

88. The method according to claim 77, wherein The at least one electrical parameter includes potential.

89. The method according to claim 77, wherein The at least one electrical parameter includes current.

90. The method according to claim 77, wherein, The electro-ablation energy includes radio frequency electrical energy.

91. The method according to claim 77, wherein, The electro-ablation energy includes pulsed field ablation electrical energy.

92. The method according to claim 77, Among them, The ablation device includes a shaft disposed proximally on the end effector; and wherein positioning the tissue engaging portion of the end effector of the ablation device close to the target tissue includes positioning the tissue engaging portion of the end effector of the ablation device using the shaft.

93. The method according to claim 92, Among them, The ablation device includes a handle disposed proximally on the shaft; and wherein positioning the tissue engaging portion of the end effector of the ablation device close to the target tissue includes positioning the tissue engaging portion of the end effector of the ablation device using the handle.

94. The method according to claim 77, Among them, The ablation device includes at least one connection element configured to electrically couple the end effector to an external ablation energy source; and wherein applying the electro-ablation energy to the end effector includes applying the electro-ablation energy to the end effector via the at least one connection element.

95. A method of ablating tissue, the method comprising: Positioning an end effector of an ablation device such that a first contact portion, a second contact portion, and an intermediate contact portion interposed between the first contact portion and the second contact portion of the end effector physically touch the tissue, wherein the intermediate contact portion includes at least one of an electrode and a semiconductor, wherein the first contact portion is in electrical communication with a first electrode, and wherein the second contact portion is in electrical communication with a second electrode; Applying electrical energy to the first electrode and the second electrode such that the magnitude of at least one electrical parameter is different between the first contact portion and the second contact portion, wherein the magnitude at the intermediate contact portion is less than the magnitude at the first contact portion and greater than the magnitude at the second contact portion.

96. An ablation device for ablating tissue, the ablation device comprising: An end effector, the end effector including A first contact portion, a second contact portion, and an intermediate contact portion interposed between the first contact portion and the second contact portion, the intermediate contact portion including a plurality of intermediate electrodes, the first contact portion being in electrical communication with a first electrode, the second contact portion being in electrical communication with a second electrode, wherein the first electrode and the second electrode are spaced apart from each other by a first distance, wherein the first electrode and the intermediate contact portion are spaced apart from each other by a second distance, wherein the second electrode and the intermediate contact portion are spaced apart from each other by a third distance, wherein the first distance is greater than the second distance or the third distance, and wherein the surface area of at least one of the first electrode and the second electrode is a multiple of the surface area of any one of the plurality of intermediate electrodes; Wherein, when the end effector contacts the tissue, the first contact portion, the intermediate contact portion, and the second contact portion are electrically coupled, and wherein, when the first electrode and the second electrode are supplied with electroablation energy, the magnitude of at least one electrical parameter is different between the first contact portion, the intermediate contact portion, and the second contact portion such that the magnitude at the intermediate contact portion is less than the magnitude at the first contact portion and greater than the magnitude at the second contact portion.

97. Any method, process, device, or system comprising one or more elements according to any one of the preceding claims.

98. Any combination of any one or more elements according to any one of the preceding claims.

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