Method and apparatus for performing tissue ablation - Patents.com

Abstract

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

Description

[Technical Field]

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

[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 technology]

[0003] The present disclosure contemplates that ablation (e.g., radiofrequency (RF) ablation) may be used as part of a surgical procedure to treat atrial fibrillation, an arrhythmia and tachycardia. RF ablation heats cardiac tissue to form lesions that disrupt abnormal electrical signals, which may be part of the process of restoring a normal heartbeat. Specific patterns of ablation can redirect electrical signals to more appropriate patterns and aid in the treatment of atrial fibrillation. RF ablation may be performed by pinching the tissue via an RF clamp or by pressing and / or suctioning the outside of the tissue via an RF pen and / or suction device. RF ablation is typically performed at 1V to 100V, 100kHz to 1000kHz, and a total power output of 1W to 100W. Tissue thickness within critical regions of the heart may range from 2mm to 15mm. The tissue is preferably ablated to achieve transmurality, whereby the ablation penetrates essentially the thickness of the cardiac tissue muscle.

[0004] The present disclosure contemplates that tissue ablation may be achieved by heating the tissue to approximately 55°C to 60°C. However, as a result of various factors during ablation, tissue may often heat beyond this range (e.g., above 100°C). Overheating of the tissue may lead to defects such as surface damage and / or tissue charring (which may affect healing time) and tissue popping (which may perforate the tissue). Additionally, as heat is generated at the tissue, some end effectors may reach high temperatures after one or more ablations. This may result in portions of the end effector heating above 55°C, potentially damaging areas of the body adjacent to the heart and in contact with the end effector.

[0005] The present disclosure contemplates that several strategies for cooling cardiac tissue include adding a heat sink to the end effector of the device containing an active cooling fluid and reducing the electrical output of the device. However, these methods may each have drawbacks. For example, the heat sink may become excessively hot after multiple ablations. Active cooling requires a source of fluid external to the device, making the device more complex and requiring more energy for ablation. Reducing electrical output may result in a decrease in the efficiency of the procedure. Summary of the Invention [Problem to be solved by the invention]

[0006] Thus, while known devices have been used safely and effectively, there is a need to provide improved devices and methods that can improve electrosurgery (e.g., ablation) of tissue while limiting unnecessary damage to the ablated or surrounding tissue. [Means for solving the problem]

[0007] The following introduces some aspects of the present disclosure to provide a basic understanding of the described technology. This introduction is not an extensive overview of all contemplated features of the disclosure, nor is it intended to identify key or critical elements of all aspects of the disclosure or to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present one or more aspects of the disclosure in an introductory form as a prelude to the more detailed description that is presented later.

[0008] One aspect of the present disclosure is to provide an ablation device for use with an energy source for applying energy to tissue, the ablation device comprising: (a) an end effector having a working surface; (b) a connector configured to electrically couple an 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 tissue, the plurality of electrodes including a first electrode and a second electrode opposite one or more intermediate electrodes, wherein, upon applying 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 the one or more intermediate electrodes each deliver an intermediate voltage, and a potential difference between the first voltage and the second voltage is greater than a potential difference between the first electrode and any intermediate voltage of the one or more intermediate electrodes, thereby ablating the tissue while limiting thermal fluctuations within the tissue and locations on the tissue surface where the surface temperature exceeds a maximum temperature.

[0009] In a more detailed embodiment of the first aspect, the end effector comprises a radiofrequency pen. In yet another more detailed embodiment, the end effector comprises a radiofrequency clamp. In a further detailed embodiment, the end effector comprises a radiofrequency pen or pod including a vacuum suction portion. In yet another more detailed embodiment, the end effector comprises an expandable device. In another more detailed embodiment, the expandable device includes an inflatable element. In a more detailed embodiment, the first electrode and the second electrode have a width greater than that of the intermediate electrode. In another more detailed embodiment, the width of the first electrode and the second electrode is 2 to 8 mm, the width of the intermediate electrode is smaller than that of the first electrode and the second electrode, and the total width, including the maximum potential difference, is between 10 and 30 mm. In yet another more detailed embodiment, the length of the multiple electrodes is configured to form a desired ablation length. In yet another more detailed embodiment, the multiple electrodes include 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 electrode, the second electrode, and the intermediate electrode are distributed in an annular pattern, with each electrode being concentric with respect to an adjacent electrode. In a further detailed embodiment, the power of each electrode is different from the power of an adjacent electrode. In yet another more detailed embodiment, the current of each electrode is different from the current of an adjacent electrode. In a more detailed embodiment, the intermediate electrode includes a resistive conductor, the resistive conductor configured to reduce the potential difference between the first electrode and the second electrode. In a more detailed embodiment, the potential difference between each adjacent electrode is uniform or non-uniform. In another more detailed embodiment, the maximum potential difference is between 10 volts and 500 volts. In yet another more detailed embodiment, the maximum 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 and 40 watts. In yet another more detailed embodiment, the applied frequency is between 50 kilohertz and 5,000 kilohertz. In a further detailed embodiment, the applied frequency is between 300 and 500 kilohertz. In yet a further detailed embodiment, multiple electrode arrays are arranged end-to-end on the tissue ablation device to extend the surface length of the ablated region while maintaining electrical and thermal energy at a width and depth within the ablated region. In a more detailed embodiment, the voltage and current of each electrode are in phase or out of phase with adjacent electrodes, the phase being the time-dependent phase of the potential of the applied AC voltage. In a more detailed embodiment, the voltage and current of each of the first and second electrodes are sinusoidal with respect to time. In another more detailed embodiment, the voltage and current of each of the first and second electrodes are square waves with respect to time. In yet another more detailed embodiment, the intermediate electrode is electrically disconnected from the first electrode and the second electrode, and the intermediate electrode carries current between the first electrode and the second electrode to reduce resistance.

[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 contacting surface; (b) a power source coupled to the end effector; and (c) an array of electrodes in electrical communication with the tissue contacting surface, wherein each electrode in the array of electrodes is held at an electrical potential, current, or power as supplied by a voltage source, the electrical potential, current, or power of each electrode being different from the electrical potential, current, or power of an adjacent electrode, the array of electrodes being configured to ablate the tissue while distributing an electrical potential over the surface of the tissue, whereby the distribution of the electrical potential reduces temperature fluctuations within the ablated tissue.

[0013] A third aspect of the present disclosure provides a method for ablating tissue, the method including: (a) positioning an end effector at a target site of tissue, the end effector having a tissue contacting surface in electrical communication with an array of electrodes; (b) applying an electrical potential, current, or power from a power source to each electrode in the array of electrodes, the array of electrodes having a distributed electrical potential and configured to ablate the tissue while distributing the electrical potential on the tissue; and (c) ablating the tissue at a distance from the end effector while minimizing heat applied to a surface of the tissue 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, wherein the first electrode, the second electrode, and the intermediate electrical element are configured to be in electrical communication with a target tissue, and the intermediate electrical element is disposed 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 a current. In yet a 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 the at least one electrical parameter of the electrical energy is incrementally varied between 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 a potential. In a more detailed embodiment, the at least one electrical parameter includes a power.

[0016] A fifth aspect of the present disclosure is to provide an electrosurgical system comprising: (a) an electrosurgical device comprising: (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 a target tissue, the intermediate electrical element being disposed between the first electrode and the second electrode; and (b) 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, the first resistor and the second resistor being electrically connected in series between the first input conductor and the second input conductor, the first electrode configured to electrically connect to the first input connector, the second electrode configured to electrically connect to the second input connector, and at least one intermediate electrode configured to electrically connect to at least one intermediate conductor 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 the handle, shaft, end effector, or connecting element of the electrosurgical device, the first input conductor and the second input conductor configured to releasably electrically couple to the electrosurgical generator, the first input conductor electrically coupled to the first electrode, the second input conductor electrically coupled to the second electrode, and the at least one intermediate electrode 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 configured to be electrically interposed between the electrosurgical device and the electrosurgical generator, the first input conductor and the second input conductor configured to releasably electrically couple to the electrosurgical generator, the first input conductor configured to releasably electrically couple to the first electrode, the second input conductor configured to releasably electrically couple to the second electrode, and the at least one intermediate electrode configured to releasably electrically couple to the at least one intermediate electrode. In a further detailed embodiment, the resistive voltage divider is disposed within the electrosurgical generator, the first input conductor configured to releasably electrically couple to the first electrode, the second input conductor configured to releasably electrically couple to the second electrode, and the at least one intermediate conductor configured to releasably electrically couple 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 electrical resistive element, wherein the first electrode, the second electrode, and the at least one intermediate electrical resistive element are configured to be in electrical communication with a target tissue, and the at least one intermediate electrical resistive element is disposed between the first electrode and the second electrode.

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

[0020] A seventh aspect of the present disclosure is to provide an electrosurgical device comprising: (a) a tissue contacting surface 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, the plurality of intermediate electrodes are sequentially disposed between the first electrode and the second electrode along the first width, and at least one electrical parameter varies among 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 respective 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 value varies in an increasing manner between the first electrode, each intermediate electrode, and the second electrode.

[0022] An eighth aspect of the present disclosure provides an ablation device for forming a lesion in a target tissue, the ablation device comprising: (a) an end effector having a tissue engaging portion configured to engage with the target tissue, the end effector being configured to be in electrical contact and including a first tissue contacting portion, a second tissue contacting portion, and an intermediate tissue contacting portion, the intermediate tissue contacting portion being disposed between the first tissue contacting portion and the second tissue contacting portion, the first tissue contacting portion, the intermediate tissue contacting portion, and the second tissue contacting portion being electrically coupled, and when the end effector is supplied with electrical ablation energy, the magnitude of at least one electrical parameter differs between the first tissue contacting portion, the intermediate tissue contacting portion, and the second tissue contacting portion, and the magnitude of the intermediate tissue contacting portion is between the magnitude of the first tissue contacting portion and the magnitude of the second tissue contacting portion.

[0023] In yet another more detailed embodiment of the eighth aspect, the tissue engaging portion comprises a discrete first electrode including a first tissue contacting portion and a discrete second electrode including a second tissue contacting portion. In yet another more detailed embodiment, the tissue engaging portion comprises a discrete intermediate electrode including an intermediate tissue contacting portion. In a further detailed embodiment, the tissue engaging portion comprises 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 a further detailed embodiment, the intermediate electrode comprises at least two sequentially arranged discrete intermediate electrodes, and the magnitude of at least one electrical parameter varies incrementally between the at least two sequentially arranged discrete intermediate electrodes. In a more detailed embodiment, the first electrode, the intermediate electrode, and the second electrode are arranged in a row, the first electrode being arranged as a first outermost electrode at a first end, and the second electrode being arranged as a second outermost electrode at a second end. In a more detailed embodiment, the first electrode is nested within the intermediate electrode, which is nested within the second electrode. In another more detailed embodiment, the first electrode is concentrically nested within the intermediate electrode, which is concentrically nested within the second electrode. In yet another more detailed embodiment, the intermediate electrode and the second electrode comprise 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-annular and disposed around the first electrode, and the second electrode is generally semi-annular 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 a generally bowtie shape. In yet another more detailed embodiment, the first electrode, the intermediate electrode, and the second electrode are truncated to a generally bowtie shape. In a further detailed embodiment, the tissue engaging portion comprises a semiconductor element including an intermediate tissue contacting portion. In yet another further detailed embodiment, the semiconductor element has a resistance higher than a resistance of the target tissue. In a more detailed embodiment, the semiconductor element further comprises a first tissue contacting portion and a second tissue contacting portion. In a more detailed embodiment, the end effector further comprises a first conductor electrically coupled to the semiconductor element near the first tissue contacting portion, and the end effector further comprises a second conductor electrically coupled to the semiconductor element near the second tissue contacting portion, the first conductor and the second conductor being configured to receive electrical ablation energy from the ablation energy source. In another more detailed embodiment, the end effector further comprises an intermediate conductor electrically coupled to the semiconductor element near the intermediate tissue contacting portion.

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

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

[0027] A ninth aspect of the present disclosure provides a method for forming a lesion in a target tissue, the method comprising: (a) positioning a tissue engaging portion of an end effector of an ablation device near the target tissue, wherein 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 and second tissue contacting portions is in electrical contact with the target tissue; and (b) applying electrical ablation energy to the end effector to form a lesion in the target tissue, wherein the magnitude of at least one electrical parameter or combination of electrical parameters differs between the first tissue contacting portion, the intermediate tissue contacting portion, and the second tissue contacting portion, the magnitude at the intermediate tissue contacting portion being smaller than the magnitude at the first tissue contacting portion and larger than the magnitude at the second tissue contacting portion.

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

[0029] In yet another more detailed embodiment of the ninth aspect, applying electrical ablation energy from the ablation energy source to the intermediate conductor includes applying the electrical ablation energy from the ablation source to the intermediate conductor such that a magnitude of at least one electrical parameter or combination of electrical parameters varies between the first conductor, the intermediate conductor, and the second conductor, and 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 electrical ablation energy from the ablation source to the intermediate conductor includes applying the electrical ablation energy from the ablation source to the intermediate conductor from the first conductor via a first resistor and from the second conductor via a second resistor. In a further detailed embodiment, applying electrical ablation energy to the end effector includes applying the electrical ablation 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 a further detailed embodiment, the at least one electrical parameter includes an electrical potential. In a more detailed embodiment, the at least one electrical parameter includes electrical current. In a more detailed embodiment, the electrical ablation energy includes radiofrequency electrical energy. In another more detailed embodiment, the electrical ablation 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 a tissue engaging portion of the end effector of the ablation device near 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 near 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 comprises at least one connection element configured to electrically couple the end effector to an external ablation energy source, and applying electrical ablation energy to the end effector includes applying the electrical ablation energy to the end effector via the at least one connection element.

[0030] A tenth aspect of the present disclosure provides a method for ablating tissue, the method comprising: (a) positioning an end effector of an ablation device so that a first contact portion, a second contact portion, and an intermediate contact portion disposed between the first contact portion and the second contact portion of the end effector are in physical contact with tissue, the intermediate contact portion including at least one of an electrode and a semiconductor, the first contact portion being in electrical communication with the first electrode, and the second contact portion being in electrical communication with the 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 differs between the first contact portion and the second contact portion, the magnitude at the intermediate contact portion being smaller than the magnitude at the first contact portion and larger than the magnitude at the second contact portion.

[0031] An eleventh aspect of the present disclosure provides an ablation device for ablating tissue, the ablation device comprising: (a) an end effector comprising a first contact portion, a second contact portion, and an intermediate contact portion disposed between the first contact portion and the second contact portion, the intermediate contact portion comprising a plurality of intermediate electrodes, the first contact portion being in electrical communication with the first electrode, the second contact portion being in electrical communication with the second electrode, the first electrode and the second electrode being spaced apart from each other by a first distance, the first electrode and the intermediate contact portion being spaced apart from each other by a second distance, the second electrode and the intermediate contact portion being spaced apart from each other by a third distance, and the first distance being The end effector includes: a first electrode having a first distance greater than the second distance or the third distance; a surface area of ​​at least one of the first and second electrodes being an integer multiple of the surface area of ​​any one of the plurality of intermediate electrodes; when the end effector contacts tissue, the first contact portion, the intermediate contact portion, and the second contact portion are electrically coupled; when the first and second electrodes are supplied with electrical ablation energy, the magnitude of at least one electrical parameter differs among the first contact portion, the intermediate contact portion, and the second contact portion, the magnitude at the intermediate contact portion being smaller than the magnitude at the first contact portion and larger than the magnitude at the second contact portion. The geometries of the first, second, and additional electrodes may be uniform in width and length among themselves, or may differ in width and length, with the intention of tailoring the applied power density as a function of other characteristics, such as placement or applied pressure.

[0032] An aspect of the present disclosure is to provide any method, process, apparatus, or system that includes one or more elements described herein. An aspect of the present disclosure is to provide any combination of any one or more elements described herein.

[0033] Other aspects, features, and embodiments of the present disclosure will become apparent to those skilled in the art after reviewing the following description of specific exemplary embodiments of the present disclosure in conjunction with the accompanying figures. Features of the present disclosure may be described with respect to certain embodiments and figures below, but all embodiments of the present disclosure may include one or more of the advantageous features described herein. In other words, while one or more embodiments may be described as having certain advantageous features, one or more of such features may also be used in accordance with various embodiments of the present disclosure described herein. Similarly, while exemplary embodiments may be described below as device, system, or method embodiments, it should be understood that such exemplary embodiments may be implemented in a variety of devices, systems, and methods.

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

[0035] [Figure 1A] 1 is a perspective view illustrating an ablation device according to one or more variations of the present disclosure. [Figure 1B] FIG. 10 is a side view illustrating one variation of an ablation device having a radiofrequency pen. [Figure 1C] FIG. 10 is a side view illustrating one variation of an ablation device having a radiofrequency pen applied to tissue. [Figure 1D] FIG. 10 is a side view illustrating one variation of an end effector having a hard backing. [Figure 1E] FIG. 10 is a side view illustrating one variation of an end effector having a soft backing. [Figure 1F] FIG. 10 is a side view illustrating one variation of an end effector having multiple stacked arrays of electrodes. [Figure 1G] FIG. 10 is a bottom view illustrating one variation of an end effector having multiple stacked arrays of electrodes. [Figure 2A] FIG. 10 is a side view illustrating one variation of an ablation device having a radiofrequency pen and a suction line. [Figure 2B] FIG. 10 is a front view illustrating one variation of an ablation device having soft packing and vacuum lines. [Figure 2C] FIG. 10 is a front view illustrating yet another variation of an ablation device having soft packing and vacuum lines. [Figure 2D] FIG. 2C is a front view illustrating the ablation device of FIG. 2B being applied to tissue. [Figure 2E] FIG. 2D is a front view illustrating the ablation device of FIG. 2C being applied to tissue. [Figure 3A] 1 is a perspective view illustrating an ablation device coupled to a generator and having an ablation clamp. [Figure 3B] FIG. 10 is a side view illustrating one variation of an ablation device having an ablation clamp. [Figure 4] FIG. 10 is a side view illustrating one variation of an ablation device having an expandable member. [Figure 5] FIG. 10 is a bottom view illustrating one variation of an ablation device having concentric electrodes. [Figure 6] FIG. 10 is a bottom view illustrating one variation of an ablation device having a semiconductor electrode in the center of the electrode array. [Figure 7] FIG. 1 is a perspective view illustrating an ablation device coupled with various electrical devices. [Figure 8] 1 is a simplified schematic diagram of an exemplary electrosurgical system including an exemplary resistive voltage divider. [Figure 9] FIG. 10 is a simplified bottom view of an exemplary electrode arrangement configuration with annotations showing exemplary maximum voltages. [Figure 10] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement configuration with annotations showing exemplary dimensions. [Figure 11] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement configuration with annotations showing exemplary dimensions. [Figure 12] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement configuration with annotations showing exemplary dimensions. [Figure 13A] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement configuration with annotations showing exemplary dimensions. [Figure 13B] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement configuration with annotations showing exemplary dimensions. [Figure 14] FIG. 2 is a simplified bottom view of an exemplary electrode arrangement disposed on a substrate. [Figure 15] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement configuration with annotations showing exemplary dimensions. [Figure 16] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement configuration with annotations showing exemplary dimensions. [Figure 17] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement configuration with annotations showing exemplary dimensions. [Figure 18] FIG. 1 is a simplified bottom view of an exemplary concentric electrode arrangement. [Figure 19] FIG. 1 is a cross-sectional view of an exemplary dome-shaped end effector having an inner electrode. [Figure 20] FIG. 1B is a bottom view of an exemplary tiled electrode arrangement. [Figure 21] 1A-1C are cross-sectional views of an exemplary electrosurgical device configured for closed-loop active cooling. [Figure 22] 1A-1C are cross-sectional views of an exemplary electrosurgical device configured for passive cooling. [Figure 23] 1A-1C are cross-sectional views of exemplary end effectors including an expandable member in the form of an inflatable element. [Figure 24] 1 is a perspective view of an exemplary electrode arrangement disposed on a substrate. [Figure 25] 1 is a perspective view of an exemplary electrode arrangement configuration. [Figure 26] FIG. 1 is a perspective view of an exemplary end effector including an electrode arrangement configuration. [Figure 27] FIG. 1 is a perspective view of an exemplary end effector including an electrode arrangement configuration. [Figure 28] FIG. 1 is a perspective view of an exemplary end effector including an electrode arrangement configuration. [Figure 29] 1A-1C are cross-sectional views of exemplary current densities in target tissue caused by a two-electrode bipolar ablation device. [Figure 30] 1 is a cross-sectional view of an exemplary current density in a target tissue caused by an exemplary ablation device including a first electrode, a second electrode, and four intermediate electrodes. [Figure 31] 11A-11C are cross-sectional views of exemplary electrical potentials in target tissue induced by an exemplary ablation device including an electrode arrangement generally similar to that shown in FIG. 10. [Figure 32] 11 is a cross-sectional view of exemplary temperatures in target tissue induced by an exemplary ablation device including an electrode arrangement generally similar to that shown in FIG. 10. [Figure 33A] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including generally rectangular electrodes. [Figure 33B] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including generally rectangular electrodes. [Figure 33C] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including generally rectangular electrodes. [Figure 34A] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested generally circular and / or annular ring electrodes. [Figure 34B] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested generally circular and / or annular ring electrodes. [Figure 34C] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested generally circular and / or annular ring electrodes. [Figure 35A] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested, generally oval-shaped ring electrodes. [Figure 35B]FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested, generally oval-shaped ring electrodes. [Figure 35C] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested, generally oval-shaped ring electrodes. [Figure 35D] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested, generally oval-shaped ring electrodes. [Figure 36A] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes. [Figure 36B] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes. [Figure 36C] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes. [Figure 36D] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes. [Figure 36E] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes. [Figure 36F] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes. [Figure 36G] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes. [Figure 36H] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested, generally stadium-shaped ring electrodes. [Figure 37A] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested generally circular and / or annular ring electrodes with truncated tips. [Figure 37B]FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested generally circular and / or annular ring electrodes with truncated tips. [Figure 37C] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested generally circular and / or annular ring electrodes with truncated tips. [Figure 37D] FIG. 1 is a simplified bottom view of an exemplary electrode arrangement including nested generally circular and / or annular ring electrodes with truncated tips. [Figure 38A] FIG. 1B is a bottom view of an exemplary electrode arrangement including a semiconductor electrode disposed between two outer electrodes. [Figure 38B] FIG. 38B is a simplified elevational view of the embodiment of FIG. 38A. [Figure 39] FIG. 1 is a simplified elevational view of an exemplary electrode arrangement comprising a semiconductor electrode including a semiconductor layer disposed on a metallic conductor. [Figure 40] 1 is a simplified elevational view of an exemplary electrode arrangement including a semiconductor electrode with a conductor embedded therein. [Figure 41] 1A-1C are simplified bottom plan views illustrating a comparison of symmetric and asymmetric electrode placement configurations. [Figure 42] FIG. 10 is a simplified bottom view illustrating the dimensions of a rectangular electrode array that can be varied. [Figure 43] FIG. 10 is a simplified bottom view illustrating the dimensions of a concentric electrode array that can be varied. DETAILED DESCRIPTION OF THE INVENTION

[0036] The detailed description set forth below in connection with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the aspects described herein may be practiced. The detailed description includes specific details intended to provide 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.

[0037] All examples and illustrative references are non-limiting and should not be used to limit the claims to the specific implementations and embodiments described herein, and their equivalents. For simplicity, reference numerals may be repeated among the various examples. This repetition is for clarity only and does not dictate a relationship between the respective embodiments. Finally, in light of this 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 specifically described in the text.

[0038] The present disclosure includes various electrosurgical devices, including ablation devices. FIG. 1A illustrates an exemplary ablation device 100, which provides context for the various alternative embodiments and optional features described herein. Unless otherwise noted, any component, feature, method, etc. described herein may be utilized, alone or in any combination, with ablation devices generally similar to ablation device 100. Ablation device 100 may have an end effector 102 connected to the distal end of shaft 104 and a handle 106 connected to the proximal end of shaft 104. Shaft 14 may be straight and substantially rigid. However, flexible, curved, malleable, articulating, or other shafts may also be used, depending on various considerations.

[0039] As can be seen in FIG. 1B , a connecting element, such as a 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 extends along the longitudinal axis of the device 100 and can have an overall width of approximately 26 mm. The end effector 102 can include a tissue-engaging portion or working surface 114. As used herein, a “working surface” can refer to a surface configured to contact target tissue. A working surface can include one or more discrete surfaces, which can be continuous or separated, and can include a surface 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 energized with electrical ablation energy, such as bipolar RF energy or pulsed electric field ablation energy. As used herein, an “electrode” can refer to an element configured to deliver electrical energy to the target tissue through contact with the target tissue. Each electrode 110 may have a smooth surface area for contacting tissue. A variety of different metals or low-electrical-resistivity materials may be used for the electrodes, providing they have sufficient conductivity to transfer electrical potential and current to tissue via ionic current density. For example, the electrodes 110 may be made of copper, nickel, gold, stainless steel, platinum, platinum-iridium, titanium, tin, metal on Kapton, polymer-metal composite, hydrogel, or combinations thereof. The tissue-contacting portion 114 may include multiple tissue-contacting locations, such as a first tissue-contacting location 114A, an intermediate tissue-contacting location 114B, and a third tissue-contacting location 114C. The intermediate tissue-contacting location 114B may be disposed between the first tissue-contacting location 114A and the third tissue-contacting location 114C. In the illustrated embodiment, the electrode 110 may form the tissue-contacting locations 114A, 114B, and 114C.

[0040] As can be seen in FIG. 1C , the graduated electrode configuration results in energy being applied to tissue while ablating it to limit temperature changes and extreme temperatures (e.g., in tissue region 120) within the tissue. As a result, surface heating of the tissue can be reduced while still achieving adequate ablation deep within the tissue ablation region 118 (e.g., lesion), for example, at a temperature of approximately 55°C. In some cases, the ablation depth after 80 seconds can be approximately 10 mm from the tissue surface. The electrodes can be independently controlled to produce consistent ablation across a desired width while accommodating for different tissue thicknesses or impedances. Power output can be adjusted based on the measured impedance and / or temperature of the tissue.

[0041] In other variations, one or more of the electrodes 110, such as one or more of the intermediate electrodes, may be replaced with a moderately electrically resistive material, such as a semiconductor material having a conductivity of about 0.1 siemens per meter (S / m) to 100 S / m. This moderately resistive semiconductor material is used to extend the electrode toward the center, thereby using the material's lower conductivity to reduce the applied voltage and current in this central region. As used herein, "semiconductor material" may refer to a material with electrical properties intermediate between a good conductor and a good insulator.

[0042] FIG. 1D shows a cross-sectional view of one variation of a rigid end effector 102. In this variation, the end effector 102 is generally rigid so that the electrodes 110 cannot substantially bend. In the illustrated embodiment, the electrodes 110 are discrete. As used herein, "discrete" may refer to electrodes that present a tissue-contacting surface that is distinct from other nearby components, such as other electrodes. For example, the end effector 102 can include a backing plastic insulator 122, which is disposed between the discrete electrodes 110. The plastic insulator 122 can be approximately 1-10 mm thick. The end effector 102 can further include a thermal conductor 124 within the plastic insulator 122 to help spread heat and minimize hot spots, although this is not critical to overall functionality. The thermal conductor 124 can be 0.01-10 mm thick. A polyimide film or other electrical insulator 128 having a thickness of approximately 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.

[0043] Multiple electrodes 110 may be disposed on a 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 separated by gaps about 0.5 mm wide. In the variation shown in FIG. 1D, the outer electrode 110 may have a width of about 4 mm, and the middle electrode may have a width of about 1.5 mm. The electrode width and configuration may be varied as needed to reduce current density, reduce surface heating, and increase the width of ablation. For example, in some embodiments, it may be advantageous to utilize relatively thin electrodes to reduce electrode mass and / or reduce heat flux from the electrodes. Additionally, multiple metal electrodes adjacent to a metal electrode or higher resistivity (e.g., semiconductor) electrodes may be used in other configurations to reduce the electrical potential on the overlying tissue surface. The total effective width of the electrode areas (e.g., from one outer electrode to the other) can be approximately 22.5 mm. Alternatively, or in combination, the electrodes 110 can be arranged in a stepped fashion in a direction perpendicular to the longitudinal axis of the end effector, thereby allowing for localized adjustment of electrical output to selectively ablate regions of the heart, and the electrical energy applied to these regions can be actively or passively controlled.

[0044] The electrode 110 can have sharp or rounded corners. Sharp corners can result in higher local current densities when heat is applied to the tissue. Optionally, the device 100 can include an active cooling mechanism for cooling the cardiac tissue and / or the device 100. The device can also optionally include a second electrically insulating layer to cover any lead wires within the electrode 110.

[0045] The electrodes 110a, 110b, 110c, 110d, 110e, and 110f may be arranged in an array. The multiple electrodes may include a first electrode 110a and a second electrode 110f opposite one or more intermediate electrodes 110b-110e. The multiple electrodes may be configured such that upon application of energy, 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 smaller, gradually increasing voltage difference relative to the outer electrodes. The electrodes 110 may be bipolar and / or multipolar. The electrodes 110 may be oriented perpendicular to the longitudinal axis of the end effector 102, parallel to the longitudinal axis of the end effector 102, or offset at an angle between 0 and 90 degrees.

[0046] The potential difference between the first voltage and the second voltage can be greater than the potential difference between the first electrode and any intermediate voltage of the one or more intermediate electrodes. The electrodes 110 can also be in the range of 0 V to 75 V, with a 15 V spacing between adjacent electrodes. For example, electrode 110a can have a voltage of 75 V, electrode 110c can have a voltage of 45 V, electrode 110d can have a voltage of 30 V, electrode 110e can have a voltage of 15 V, and electrode 110f can have a voltage of 0 V. The electrodes 110 can also be in the range of 0 V to 50 V, with a 10 V spacing between adjacent electrodes. In other variations, the maximum potential difference can be between 10 V and 500 V, with varying spacing between the electrodes 110. In other variations, the voltage spacing may not be constant between each electrode. In other variations, instead of voltage, other electrical parameters, such as current or power, can be varied in steps between the electrodes.

[0047] A potential difference between electrodes 110 and a resulting gradient in the voltage of the end effector can be achieved. The voltage can be supplied through resistors and / or circuitry in ablation device 100 that modifies the potential applied to each electrode as initially supplied from a power source connected to ablation device 100 (e.g., an ablation sensing unit (ASU) generator 308 as described further herein). The voltage can be supplied through independent power sources, or a combination thereof.

[0048] The stepped electrode may limit the potential difference, and therefore the current density, at the upper surface of the tissue while maintaining current density deep in the tissue, allowing for safer and more efficient ablation. The voltage applied by the electrode 110 may also be cycled on and off at intervals to balance ablation depth and surface temperature as needed.

[0049] FIG. 1E shows a cross-sectional view of one variation of a flexible end effector 102. To provide flexibility to the end effector 102, a silicone insulator 130 may be utilized as a backing. The silicone insulator 130 may be approximately 1-10 mm thick. The insulator may be made from filled polyurethane or other elastomer, standard plastic, glass-filled or carbon-filled polymer, polyimide on aluminum, various metals with a vacuum suction and sealing, or a combination thereof. A filled silicone or other elastomeric thermal conductor 132 may be provided toward the work surface 114 of the end effector 102, although this is not critical to overall functionality. The filled elastomeric thermal conductor 132 may be approximately 0.1-10 mm thick. The thermal conductor 132 may alternatively be formed from foamed polyurethane or other elastomer. Both the silicone insulator 130 and the filled silicone thermal conductor 132 are flexible, allowing the end effector 102 to flex against cardiac tissue and conform to the curved surface of the heart, thereby increasing the tissue contact area for ablation. The end effector 102 may further include a metal thermal conductor 124 within the silicone insulator 130, although this is not critical to overall functionality. The metal thermal conductor 124 may be approximately 0.01 to 10 mm thick. A polyimide film 128, approximately 0.1 mm thick, may be attached to the aluminum thermal conductor 124 via adhesive or thermal bonding process 126. Overall thermal efficiency and mechanical flexibility can be controlled by varying the layer thickness and material modulus of the end effector 102 components.

[0050] FIG. 1F shows a cross-sectional view of a variation of the end effector 102 having multiple sets of electrodes 110 (e.g., two sets of six electrodes each). Multiple stacked rectangular electrode arrays can be arranged end-to-end on the tissue ablation device 100 to extend the surface length of the ablated region while maintaining electrical and thermal energy in the width and depth of the ablated 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 from 0V to 50V with a 10V spacing between adjacent electrodes. The electrodes 110 can also range from 0V to 75V with a 15V spacing between adjacent electrodes. The total length of the active area can be approximately 45 mm, but may depend on the total number of sets of electrodes 110. FIG. 1G shows a bottom view of two sets of electrodes 110 positioned end-to-end on the end effector 102. In some variations, the effective width of the electrode area (e.g., from one outer electrode to the other) can be less than about 12 mm to fit through trocars used in minimally invasive surgical procedures.

[0051] Alternatively, or in combination, the contact layer of the electrode 110 can be roughened and then coated with a thin polymer film with high ionic conductivity (e.g., ion-doped hydrogel) to reduce the impedance between the tissue and the metal, increase capacitance, and thereby reduce surface heating. Additionally, a heat sink behind the electrode 110 can reduce the surface temperature and further help keep the upper surface of the end effector 102 cool. The heat sink can have different thicknesses depending on various factors (e.g., the diameter of the trocar). Hydrogel can also be used to reduce adhesion between the tissue and the electrode 110. Tissue currents can increase with increased capacitance and thus decreased interfacial impedance between the electrode and tissue. Interfacial impedance generally decreases as the surface area of ​​the electrode increases. As the tissue is ablated and dehydrated, the interfacial impedance and tissue conductivity decrease.

[0052] FIG. 2A shows an ablation device 100 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 either 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 in the end effector 102. The suction line 200 can provide a vacuum to adhere to the tissue without applying unnecessary external force to the tissue. The vacuum can ensure more efficient ablation after connection of the electrode 110. Efficient ablation can be measured via time to transmural penetration, required power, uniformity of heating, ablation depth, underside backside temperature, low tissue surface damage, or a combination thereof.

[0053] 2B, the end effector 102 can have some of the characteristics of the soft end effector 102 of FIG. 1E, but has an opening 202 at the distal end of the suction line 200. This opening 202 can be formed with an open-cell foam layer to support the entire structure and reduce backside heating, molded into a gap, molded into a connector to connect to the opening 202, or a combination thereof. A gap 204 can be created in the electrode 110, insulating film 128, adhesive 126, thermal conductor 132, and thermal conductor 134 to connect the opening to the outer surface of the electrode 110.

[0054] 2C shows another variation of the end effector 102 including the suction line 200 and having a hard shell 206 along with the silicone insulator 130. The silicone insulator 130 can have a thickness of about 6 mm or less. The electrode 110 is machined separately from the opening 202 in the silicone insulator 130, which can facilitate manufacturing. The hard shell 206 can provide greater rigidity to the end effector 102 when the soft edge 208 extends partially beyond the electrode 110.

[0055] As can be seen in FIG. 2D , the end effector 102 can be placed next to target tissue, such as cardiac tissue 116. The end effector 102 can then be actuated by a suction line 200 that provides a vacuum to an opening 202. The vacuum passes through gap 204 to the electrode 110, creating a vacuum that draws the tissue 116 between the electrode 110 and forms a consistent electrical connection with the electrode 110. The electrode 110 can thus be oriented across the tissue, allowing the current to penetrate deeper into the tissue. When desired, the end effector 102 can be bent along its longitudinal axis, perpendicular to its longitudinal axis, or alternatively between them.

[0056] Alternatively, as can be seen in FIG. 2E, tissue can be drawn into the end effector 102 via suction line 200 (see FIG. 2A). After the tissue is pulled against or at least partially drawn into the end effector 102, the silicone insulator 130 of the end effector 102 can have a soft edge 208 that extends partially beyond the electrode 110, allowing the end effector 102 to encase and seal the cardiac tissue. When vacuum is applied, the cardiac tissue is drawn against the electrode 110, which can increase ablation efficiency by improving contact between the electrode 110 and the cardiac tissue, particularly in minimally invasive procedures.

[0057] 3A shows an ablation device 100 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 variation, the end effector 102 may be a surgical ablation clamp, with RF energy flowing between the two sides of the bipolar clamp. The surgical ablation clamp can enhance electrical contact with the tissue and increase 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 popping during the procedure.

[0058] The end effector 102 can have a proximal jaw 300 and a distal jaw 302. While the proximal and distal jaws 300, 302 are shown spaced apart to receive tissue therebetween, at least one of the proximal and distal jaws 300, 302 can be movable to clamp tissue therebetween. To this end, the proximal and distal jaws 300, 302 are operably coupled to a closure trigger 306 extending proximally from the handle 106, which is operable with one hand such that distal movement of the closure trigger 306 brings the proximal and distal jaws 300, 302 together. Similarly, proximal movement of the closure trigger 306 separates the proximal and distal jaws 300, 302. The proximal and distal jaws 300, 302 are shown extending at an angle from the shaft 104, but may be at any angle with the shaft 104. Electrodes 110 are positioned along the jaws 300, 302 to apply energy to opposite sides of the tissue, flowing the energy through the thickness of the tissue to create transmural ablations. The electrodes 110 may each have a width of approximately 0.3 mm, a height of approximately 0.7 mm, and a length of approximately 63.5 mm.

[0059] As can be seen in the cross-sectional view of the end effector 102 in FIG. 3B, the electrode 110 may be disposed on the working surfaces of the jaws 300, 302. The electrode 110 may be configured in any configuration as described previously or as described below. The jaws 300, 302 may be used to clamp the tissue 116 before energy is applied to the electrode 110. The energy may be applied via an ASU generator 308, which is described further herein.

[0060] The clamping pressure can force the jaws 300, 302 into the tissue, forming a gap 304 that is typically smaller than the thickness of the tissue to be ablated.

[0061] As can be seen in FIG. 4 , the end effector 102 can include an expandable member 400. An air or gas flow path 402 is connected to the expandable member 400 to selectively deflate and inflate the expandable member 400. The air flow path 402 can be disposed either within the shaft 104 or along the exterior of the shaft 104. Alternatively, or in combination, the expandable member 400 can be actuated within an actuation cable also disposed within the shaft 104 or along the exterior of the shaft 104. The expandable member 400 can also be a balloon.

[0062] FIG. 5 illustrates a nested, concentric array electrode configuration. As used herein, "nested" may refer to an arrangement in which one or more electrodes are generally disposed within one or more other electrodes, such as an inner electrode 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 around a common central point or shape. Some exemplary electrode arrays may be nested, concentric, or both nested and concentric. The electrode 110 may take the form of an active electrode as a circular electrode 500a and rings 500b-f, each electrode in the array of electrodes being concentric with respect to adjacent electrodes. The circular electrode 500a and rings 500b-f may have stepped potential differences between adjacent electrodes. For example, the potential differences may vary at uniform or non-uniform intervals from the outermost ring 500f to the innermost electrode 500a. As such, the stepped potential difference of the annularly distributed electrodes can achieve deep ablation in cardiac tissue while minimizing superficial heating in the tissue.

[0063] FIG. 6 illustrates a device 100 with one or more inner electrodes or resistive conductors (e.g., semiconductor electrodes) 600a, 600b in the center of the array of electrodes 110. The one or more resistive conductors (e.g., semiconductor electrodes) are configured to reduce the potential difference between the electrodes and may be constructed of a medium-resistivity material (e.g., approximately 0.01 S / m to 1000 S / m). The resistive conductors 600a, 600b can be disconnected from the external circuit and conduct current to reduce the resistance between the outermost electrodes 100a, 100f, thereby reducing heating and temperature rise at the tissue surface. In some exemplary embodiments, the resistive conductors and / or semiconductor elements can have a resistivity greater than that of the target tissue. In some exemplary embodiments, the resistive conductors and / or semiconductor elements can have a resistivity that is approximately the same as that of the target tissue.

[0064] FIG. 7 shows ablation device 100 coupled to an electrical cable 108. Electrical cable 108 may extend to a power source at its proximal end. During ablation, the power source can sense and measure tissue properties, such as impedance between electrodes 110 (see, e.g., FIG. 4), as the tissue is ablated, which may change electrical parameters, such as power, current, and voltage. Ablation device 100 may be coupled to cable 108, which operably couples ablation device 100 to a number of different common operating room instruments, devices, and / or sensors, including an ASU generator 308 or similar generator for creating lesions using electrodes 110 (FIG. 1B), a pacing monitor 700 for applying electrical stimulation to tissue, an impedance monitoring system 702 for measuring tissue impedance, and an electrical recording device 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, cable 108 in combination with an electrosurgical device such as ablation device 100 can provide a surgeon with a single or multiple electrode devices that can replace many existing electrode handheld devices for use in surgical procedures. A switch 706 can be added to interconnector 704 to operatively connect or disconnect one or more of the interconnected devices from the electrodes of the surgical device. Additionally, other electrical circuits or components, such as diodes or switching circuits, can be incorporated within interconnector 704. This circuitry can protect interconnected sensing equipment from the ablation energy or provide real-time control or switching circuitry. Thus, the surgeon activates ASU generator 308 with a foot pedal, and interconnector 704 engages and protects sensitive equipment such as electrical recording device 708. For ablation device 100, each of the interconnected devices can be operatively connected or disconnected to a first pole electrode and / or a second pole electrode, or any other electrode.Interconnector 704 may accommodate additional electrodes if present on the surgical device that may be connected to interconnector 704. Electrodes may be connected in any combination that meets the requirements of the energy delivery or sensing device, which may be accomplished with interconnector 704. The power and / or current of each electrode may be different from the power and / or current of adjacent electrodes.

[0065] The total power output of the device 100 can be, for example, between 1 watt and 200 watts. The applied frequency of the device can be, for example, between 50 kilohertz and 5,000 kilohertz. The voltage and current of each electrode can be in phase or out of phase with the adjacent electrode. The phase can be a time-dependent phase of the applied potential. The voltage and current of each electrode can be a sinusoidal wave with respect to time or a square wave with respect to time. Power can be applied in multiple time steps that utilize heat conduction through the tissue to heat the tissue deep without overheating the tissue surface.

[0066] 8 illustrates a simplified schematic diagram of an exemplary electrosurgical system 1000 including an exemplary resistive voltage divider 1002 in accordance with at least some aspects of the present disclosure. Electrosurgical system 1000 may generally be similar in structure and operation to other electrosurgical systems and related components described herein, and repeated descriptions of similar structure and operation have been omitted for the sake of brevity. In the illustrated embodiment, the voltage divider includes multiple series-connected resistive elements (e.g., resistors R1, R2, R3, R4, and R5), which are electrically connected between a first input conductor 1004 and a second input conductor 1006.

[0067] In the illustrated embodiment, first input conductor 1004 and second input conductor 1006 comprise a bipolar output of electrosurgical generator 1008. In the illustrated embodiment, first intermediate conductor 1010 is electrically connected between resistor R1 and resistor R2, second intermediate conductor 1012 is electrically connected between resistor R2 and resistor R3, third intermediate conductor 1014 is electrically connected between resistor R3 and resistor R4, and fourth intermediate conductor 1016 is electrically connected between resistor R4 and resistor R5.

[0068] 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.

[0069] In some exemplary embodiments, resistors R1, R2, R3, R4, and R5 may have substantially equal electrical resistances. For example, resistors R1, R2, R3, R4, and R5 may include 100 Ω resistors. Thus, some such embodiments may have substantially equal potential (e.g., voltage) differences between adjacent electrodes. In alternative embodiments, one or more of resistors R1, R2, R3, R4, and R5 may have a substantially different electrical resistance than at least one other resistor of resistors R1, R2, R3, R4, and R5.

[0070] In the illustrated embodiment, the voltage divider 1002 is electrically disposed between the electrosurgical generator 1008 and an electrosurgical device 1030 including electrodes 1018, 1020, 1022, 1024, 1026, 1028. In some exemplary embodiments, the voltage divider 1002 may be provided within an interface component configured to be releasably electrically connected 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, where the voltage divider is electrically connected within the electrosurgical generator 1008 and the electrosurgical device 1030 is configured to be releasably electrically connected to the voltage divider 1002. In some alternative embodiments, the voltage divider 1002 may be provided as part of the electrosurgical device 1030, where the voltage divider 1002 is electrically connected within the electrosurgical device 1030 and the voltage divider 1002 is configured to be releasably electrically connected to the electrosurgical generator 1008.

[0071] 9 is a simplified bottom view of an exemplary electrode arrangement 1100, with annotations showing exemplary maximum voltages, 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 associated components described herein, and repeated descriptions of similar structure and operation have been omitted for 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 which together form a generally rectangular array.

[0072] The respective potentials (voltages) of each electrode 1118, 1120, 1122, 1124, 1126, 1128 are described in the notes of FIG. 9 in terms of a maximum voltage between the first electrode 1118 and the second electrode 1120 of ΔV_max, which may correspond to the maximum voltage difference between the first input conductor 1004 and the second input conductor 1006 supplied to the voltage divider 1002 of FIG. 8. The maximum voltage of the first electrode 1118 may be approximately +½ΔV_max, the maximum voltage of the second electrode 1120 may be approximately −½ΔV_max, the maximum voltage of the first intermediate electrode 1122 may be approximately +½ΔV_max−½ΔV_max, the maximum voltage of the second intermediate electrode 1124 may be approximately +½ΔV_max−½ / 5ΔV_max, the maximum voltage of the third intermediate electrode 1126 may be approximately +½ΔV_max−¾ΔV_max, and / or the maximum voltage of the fourth intermediate electrode 1128 may be approximately +½ΔV_max−¾ΔV_max. These maximum voltages are based on resistors R1, R2, R3, R4, and R5 having substantially equal electrical resistances, although one skilled in the art would be able to calculate similar maximum voltages for alternative arrangements including resistors R1, R2, R3, R4, and R5 having unequal electrical resistances.

[0073] 10 is a simplified bottom view of an exemplary electrode arrangement 1200, with annotations showing exemplary dimensions, all according to at least some embodiments of the present disclosure. The electrode arrangement 1200 may be generally similar in structure and operation to other electrode arrangements and associated components described herein, and repeated descriptions of similar structure and operation have been omitted for the sake of brevity. In particular, the electrode arrangement 1200 is generally similar to that illustrated in FIGS. 1F and 1G and described above.

[0074] For clarity, various exemplary 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 consistency of description only and are not intended to limit the scope of the present disclosure to any particular orientation of the electrode arrangement configuration relative to other components of the electrosurgical device.

[0075] In the illustrated embodiment, the electrode arrangement 1200 includes a repeating arrangement of a first electrode 1202, a second electrode 1204, and four intermediate electrodes 1206, 1208, 1210, 1212, each generally rectangular and together forming a generally rectangular array. In this embodiment, the repeating arrangements are generally arranged as mirror images, such that the second electrodes 1204 are closest to each other, thus avoiding adjacent electrodes having a voltage difference of V+ / V− (e.g., ΔV_max). While FIG. 10 illustrates an embodiment including two mirror image arrangements, it is within the scope of this disclosure to utilize any number of mirror image arrangements in a similar generally repeating manner.

[0076] In the illustrated embodiment, the first electrode 1202 and the second electrode 1204 are 3.0 mm wide, and the intermediate electrodes 1206, 1208, 1210, and 1212 are 1.0 mm wide. In the illustrated embodiment, the gap between adjacent electrodes is 0.5 mm. Thus, the overall width of the illustrated electrode arrangement is 25.5 mm. In the illustrated embodiment, the electrodes 1202, 1204, 1206, 1208, 1210, and 1212 have equal lengths of 7.25 mm. It will be understood that these dimensions are merely illustrative and should not be considered limiting in any way.

[0077] 11 is a simplified bottom view of an exemplary electrode arrangement configuration 1300, with annotations showing exemplary dimensions, all according to at least some embodiments of the present disclosure. The electrode arrangement configuration 1300 may be generally similar in structure and operation to other electrode arrangement configurations and associated components described herein, and repeated descriptions of similar structure and operation have been omitted for the sake of brevity. In particular, the electrode arrangement configuration 1300 is generally similar to that illustrated in FIG. 10 and described above.

[0078] In the illustrated embodiment, the electrode arrangement configuration 1300 is similar to the mirror image repeating configuration shown in Figure 10, except that the adjacent second electrodes 1204 of Figure 10 are replaced with a single wider second electrode 1304 in the embodiment of Figure 11, avoiding gaps between these electrodes 1204. Thus, the electrode arrangement configuration 1300 of Figure 11 includes a first electrode 1302 at each lateral end of the mirror image arrangement, a generally central, relatively wide second electrode 1304, and four middle electrodes 1306, 1308, 1310, 1312 in each repeating configuration. While Figure 11 illustrates an embodiment including two mirror image configurations, it is within the scope of this disclosure to utilize any number of mirror image configurations in a similar generally repeating manner.

[0079] In the illustrated embodiment, the first electrode 1302 is 4.0 mm wide, the second electrode 1304 is 6.0 mm wide, and the intermediate electrodes 1306, 1308, 1310, and 1312 are 1.5 mm wide. In the illustrated embodiment, the gap between adjacent electrodes is 0.5 mm. Thus, the overall width of the illustrated electrode arrangement is 31.0 mm. In the illustrated embodiment, the electrodes 1302, 1304, 1306, 1308, 1310, and 1312 have equal lengths of 7.3 mm. It will be understood that these dimensions are merely illustrative and should not be considered limiting in any way.

[0080] 12 is a simplified bottom view of an exemplary electrode arrangement configuration 1400, with annotations showing exemplary dimensions, all according to at least some embodiments of the present disclosure. The electrode arrangement configuration 1400 may be generally similar in structure and operation to other electrode arrangement configurations and associated components described herein, and repeated descriptions of similar structure and operation have been omitted for the sake of brevity. In particular, the electrode arrangement configuration 1400 is generally similar to that illustrated in FIGS. 1D and 1E and described above.

[0081] In the illustrated embodiment, the first electrode 1402 and the second electrode 1404 are 6.0 mm wide, and the intermediate electrodes 1406, 1408, 1410, and 1412 are 2.3 mm wide. In the illustrated embodiment, the gap between adjacent electrodes is 0.7 mm. Thus, the overall width of the illustrated electrode arrangement is 24.7 mm. In the illustrated embodiment, the electrodes 1402, 1404, 1406, 1408, 1410, and 1412 have equal lengths of 7.3 mm. It will be understood that these dimensions are merely illustrative and should not be considered limiting in any way.

[0082] 13A and 13B are simplified bottom views of exemplary electrode arrangement configurations 1500A, 1500B, all annotated to show exemplary dimensions, according to at least some aspects of the present disclosure. The electrode arrangement configurations 1500A, 1500B may generally be similar in structure and operation to other electrode arrangement configurations and associated components described herein, and repeated descriptions of similar structure and operation have been omitted for brevity. In particular, the electrode arrangement configurations 1500A, 1500B are generally similar to those illustrated in FIG. 12 and described above, except that the length L of the electrode arrangement configurations 1500A, 1500B is substantially longer. Notably, each electrode in the embodiment of FIG. 12 is longer than it is wide, while the overall electrode arrangement configuration of FIG. 12 is wider than it is long. In contrast, in the embodiment of FIGS. 13A and 13B, each electrode is longer than it is wide, and the overall electrode arrangement configurations 1500A, 1500B are longer than it is wide.

[0083] In the illustrated embodiment, the first electrodes 1502A, 1502B and the second electrodes 1504A, 1504B are 4.0 mm wide, and the intermediate electrodes 1506A, 1506B, 1508A, 1508B, 1510A, 1510B, 1512A, 1512B are 1.5 mm wide. In the illustrated embodiment, the gap between adjacent electrodes is 0.5 mm. Thus, the overall width of the illustrated electrode arrangement is 16.5 mm. In the embodiment illustrated in FIG. 13A, the electrodes 1502A, 1504A, 1506A, 1508A, 1510A, 1512A have equal lengths of 25.0 mm. In the embodiment illustrated in FIG. 13B, the electrodes 1502B, 1504B, 1506B, 1508B, 1510B, 1512B have equal lengths of 50.0 mm. It will be understood that these dimensions are merely illustrative and should not be considered limiting in any way.

[0084] Generally, in some exemplary embodiments according to at least some aspects of the present disclosure, the width of the first and second electrodes may be about 4.0 mm, the width of the middle electrode may be about 0.5-1.5 mm, and the gap between the electrodes may be about 0.5-1.5 mm for a total width of about 15.0-20.0 mm. In similar alternative embodiments, these dimensions may vary within about ±25% of these values.

[0085] Generally, in some exemplary embodiments according to at least some aspects of the present disclosure, the width of the first and second electrodes may be about 6.0 mm, the width of the middle electrode may be about 2.0-3.0 mm, and the gap between the electrodes may be about 0.5-1.5 mm for a total width of about 25.0-30.0 mm. In similar alternative embodiments, these dimensions may vary within about ±25% of these values.

[0086] 14 is a simplified bottom view of an exemplary electrode arrangement 1600 disposed on a substrate 1602, according to at least some embodiments of the present disclosure. The electrode arrangement 1600 may be generally similar in structure and operation to other electrode arrangements and associated components described herein, and repeated descriptions of similar structure and operation have been omitted for the sake of brevity. In particular, the electrode arrangement 1600 is generally similar to those illustrated in FIG. 11 (with length L extended) and FIG. 13 (with electrodes repeated) and described above.

[0087] 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.

[0088] 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 soldering pads 1608. Generally, the electrical conductors 1606 are configured to electrically couple a particular electrode to the soldering pads 1608 in a desired electrical configuration. The soldering pads 1608 are configured to facilitate a solder connection to an electrical wire or other conductor, which may be electrically connected, for example, to an electrosurgical generator and / or sensing device. In the illustrated embodiment, the connection / soldering area 1604 is approximately 20.0-25.0 mm in length. During use, a portion of the electrode arrangement 1600 on the substrate 1602 is exposed, allowing contact with the target tissue. The remainder of the substrate 1602 (e.g., the portion including the connections / soldering areas 1604) may be housed within the end effector or shaft or otherwise protected and / or insulated from contact with the surgical area.

[0089] In the illustrated embodiment, the electrode arrangement 1600 and substrate 1602 are fabricated in the form of a flexible printed circuit. The substrate may comprise, for example, Kapton® polyimide, and / or the electrodes may be fabricated from, for example, copper plated with nickel and gold. In this exemplary embodiment, the substrate may be approximately 0.05 mm thick, and / or the electrodes may be approximately 0.036 mm thick. In some exemplary embodiments, the substrate and / or electrodes may be generally flexible, such as to conform to other end effector components and / or to anatomical tissue.

[0090] 15 is a simplified bottom view of an exemplary electrode arrangement configuration 1620, with annotations showing exemplary dimensions, according to at least some aspects of the present disclosure. The electrode arrangement configuration 1620 may generally be similar in structure and operation to other electrode arrangement configurations and associated components described herein, and repeated descriptions of similar structure and operation have been omitted for brevity. In particular, the electrode arrangement configuration 1620 is generally similar to that illustrated in FIG. 13A and described above, except that the electrode arrangement configuration 1620 includes at least one electrode having a different length, whereas all of the electrodes in the embodiment of FIG. 13A are substantially the same length.

[0091] In the illustrated embodiment, the first electrode 1622 and the second electrode 1624 are 4.0 mm wide, and the intermediate electrodes 1626, 1628, 1630, and 1632 are 1.5 mm wide. In the illustrated embodiment, the gap between adjacent electrodes is 0.5 mm. Thus, the overall 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, and 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 centrally disposed intermediate electrodes 1628, 1630. That is, the centrally disposed intermediate electrodes 1628, 1630 are the longest, and the outer first and second electrodes 1622, 1624 are the shortest. In the illustrated embodiment, the centrally disposed intermediate electrodes 1628, 1630 are 25 mm in length. In general, the electrode dimensions may be selected to create a desired ablation shape. It will be understood that these dimensions are merely exemplary and should not be considered limiting in any way.

[0092] 16 is a simplified bottom view of an exemplary electrode arrangement configuration 1640, with annotations showing exemplary dimensions, according to at least some aspects of the present disclosure. The electrode arrangement configuration 1640 may be generally similar in structure and operation to other electrode arrangement configurations and associated components described herein, and repeated descriptions of similar structure and operation have been omitted for the sake of brevity. In particular, the electrode arrangement configuration 1640 is generally similar to that illustrated in FIG. 13A and described above, except that the electrode arrangement configuration 1640 includes at least one electrode having a different shape (e.g., generally trapezoidal), and all of the electrodes in the embodiment of FIG. 13A are generally rectangular.

[0093] In the illustrated embodiment, the first electrode 1642 and the second electrode 1644 are 4.0 mm wide, and the intermediate electrodes 1646, 1648, 1650, and 1652 are 1.5 mm wide. In the illustrated embodiment, the gap between adjacent electrodes is 0.5 mm. Thus, the overall 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 their parallel sides facing outward, away from the intermediate electrodes 1646, 1648, 1650, and 1652. The intermediate electrodes 1646, 1648, 1650, and 1652 are generally rectangular. In the illustrated embodiment, the electrodes are 25 mm long. In general, the shape of the electrodes can be selected to create a desired ablation shape. It will be understood that these dimensions are merely exemplary and should not be considered limiting in any way.

[0094] 17 is a simplified bottom view of an exemplary electrode arrangement configuration 1660, with annotations showing exemplary dimensions, according to at least some aspects of the present disclosure. The electrode arrangement configuration 1660 may generally be similar in structure and operation to other electrode arrangement configurations and associated components described herein, and repeated descriptions of similar structure and operation have been omitted for brevity. In particular, the electrode arrangement configuration 1660 is generally similar to that shown in FIG. 13A and described above, except that the electrode arrangement configuration 1660 includes at least one gap between electrodes having different widths, all of the gaps in the embodiment of FIG. 13A being generally uniform in addition to at least one intermediate electrode having a different width, and all of the intermediate electrodes had a uniform width in the embodiment of FIG. 13A.

[0095] In the illustrated embodiment, the first electrode 1662 and the second electrode 1664 are 4.0 mm wide, the intermediate electrodes 1666, 1672 closest to the first and second electrodes are 1.5 mm wide, and the centrally disposed intermediate electrodes 1668, 1670 are 0.75 mm wide. 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 overall width of the illustrated electrode arrangement 1660 is 16.5 mm. In the illustrated embodiment, the electrodes are 25 mm in length. In general, the gap width can be selected to create a desired ablation shape. It will be understood that these dimensions are merely exemplary and should not be considered limiting in any way.

[0096] 18 is a simplified bottom view of an exemplary nested concentric electrode arrangement 1720, according to 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 associated components described herein, and repeated descriptions of similar structure and operation have been omitted for the sake of brevity. In particular, the electrode arrangement 1720 is generally similar to that illustrated in FIG. 5 and described above, except that the electrode arrangement 1720 includes a generally annular center electrode 1724, and the center electrode 500a of the embodiment of FIG. 5 is generally circular.

[0097] In the illustrated embodiment, a first (e.g., outer) electrode 1722 and a 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 and radially disposed between the first electrode 1722 and the second electrode 1724. In the illustrated embodiment, the electrode arrangement configuration 1720 includes a generally circular central gap 1734 as well as annular gaps between adjacent pairs of electrodes.

[0098] 19 shows a cross-sectional view of an exemplary dome-shaped end effector 1820 with an inner electrode, in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the end effector 1820 includes a structural element 1822 and a plurality of electrodes 1824, 1826, 1828, 1830, 1832, and 1834. The structural element 1822 forms a generally concave portion, and the electrodes 1824, 1826, 1828, 1830, 1832, and 1834 are disposed on an inner surface 1836 thereof. Thus, the electrodes provide a generally concave tissue-contacting surface 1838. The size and arrangement of the electrodes 1824, 1826, 1828, 1830, 1832, and 1834 are similar to other electrode arrangements described herein, and repeated description will be omitted for brevity. In some exemplary embodiments, structural element 1822 may be substantially rigid when subjected to forces expected during intended use. In some exemplary embodiments, structural element 1822 may be at least partially deformable (e.g., elastically and / or plastically) when subjected to forces expected during intended use.

[0099] FIG. 20 illustrates a bottom view of an exemplary tiled rectangular electrode arrangement 1850 in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the tiled arrangement includes a first electrode arrangement 1200 ( FIG. 10 ) longitudinally disposed near a second electrode arrangement 1200. In the illustrated embodiment, a longitudinal gap 1852 is disposed between the first and second electrode arrangements 1200. While FIG. 20 illustrates two longitudinally disposed electrode arrangements 1200, alternative embodiments may include a tiled arrangement of two or more other electrode arrangements that are laterally offset, linearly offset, and / or angularly offset, as disclosed herein.

[0100] FIG. 21 illustrates a cross-sectional view of an exemplary electrosurgical device 1860 configured for closed-loop active cooling in accordance with at least some aspects of the present disclosure. 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 configured to deliver cooling fluid to an internal chamber 1868 of the end effector 1864. A return conduit 1870 is configured to direct cooling fluid away from the internal chamber 1868 of the end effector 1864. The end effector 1864 is configured such that cooling fluid flowing through the internal chamber 1868 removes heat from the electrodes 1862. Some embodiments include a thermal conductor, such as the thermal conductor 124 described above with reference to FIG. 1D , which may be configured to conduct heat from the electrodes 1862 to the cooling fluid in the internal chamber 1868. Exemplary cooling fluids may include, for example, without limitation, water and / or saline. The supply conduit 1866 and / or the return conduit 1870 may be operably coupled to a source of cooling fluid and / or a container for used cooling fluid. Alternatively, the return conduit 1870 may be omitted and the cooling fluid may be expelled from the electrosurgical device 1860 and delivered to the surgical space.

[0101] 22 illustrates a cross-sectional view of an exemplary electrosurgical device 1880 configured 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 an 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 may flow into the heat sink 1886. In some exemplary embodiments, the heat sink 1886 may be made from a solid material having a relatively high thermal mass and / or a relatively high thermal conductivity, such as a metal.

[0102] FIG. 23 illustrates a cross-sectional view of an exemplary end effector 1920 including an expandable member in the form of an expandable element 1922, in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the end effector 1920 comprises a first electrode array 1924 and a second electrode array 1926 disposed on one or more outer surfaces thereof. The end effector 1920 may be reconfigurable between a collapsed configuration and an expanded configuration (shown in FIG. 23 ), such as by inflation and / or deflation of the expandable element 1922. The expandable element 1922 may be generally disposed internal to the end effector 1920 and / or serve as a structural element of the end effector 1920. In the illustrated embodiment, each electrode array 1924, 1926 provides a generally convex tissue-contacting surface 1928, 1930, respectively, when the end effector is in the expanded configuration. The size and arrangement of the electrode arrays 1924, 1926 may be similar to other electrode arrangements described herein, and a repeated description will be omitted for the sake of brevity.

[0103] 24-28 illustrate exemplary embodiments including various optional features and configurations according to at least some aspects of the present disclosure. FIG. 24 is a perspective view of an exemplary generally rectangular electrode arrangement 1700 disposed on a substrate 1702 according to at least some aspects of the present disclosure. The electrode arrangement 1700 and substrate 1702 may be generally similar in structure and operation to other electrode arrangements and associated components described herein, and repeated descriptions of similar structure and operation have been omitted for the sake of brevity. In particular, the electrode arrangement 1700 and substrate are generally similar to those illustrated in FIG. 14 and described above. In the illustrated embodiment, connections / soldering areas 1704 are shown with respective electrical wires 1706 soldered to respective solder pads 1708.

[0104] 25 illustrates a perspective view of an exemplary electrode arrangement 1800 according to 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 structure and operation have been omitted for brevity. In particular, the electrode arrangement 1800 substrate is generally similar to that illustrated in FIG. 13 and described above. Solder connections 1802 are visible in the connection / soldering area 1804 adjacent to the active electrode arrangement 1800. Additionally, the illustrated embodiment includes a plurality of suction openings 1806.

[0105] 26 illustrates a perspective view of an exemplary end effector 1900 including an electrode arrangement 1902, according to at least some embodiments of the present disclosure. The end effector 1900 may be generally similar in structure and operation to other end effectors and related components described herein, and repeated descriptions of similar structure and operation have been omitted for the sake of brevity. In particular, the electrode arrangement 1902 is generally similar to that illustrated in FIG. 11 and described above.

[0106] 27 illustrates a perspective view of an exemplary end effector 2000 including an electrode arrangement 2002, according to 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 related components described herein, and repeated descriptions of similar structure and operation have been omitted for the sake of brevity. In particular, the electrode arrangement 2002 is generally similar to that illustrated in FIG. 13 and described above. 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 by approximately 25.0 mm.

[0107] 28 illustrates a perspective view of an exemplary end effector 2100 including an electrode arrangement configuration 2102, according to at least some embodiments 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 structure and operation have been omitted for the sake of brevity. In particular, the electrode arrangement configuration 2102 is generally similar to that illustrated in FIG. 11 and described above.

[0108] Figure 29 illustrates a cross-sectional view of exemplary current densities within target tissue 2200 induced by a two-electrode 2202, 2204 bipolar ablation device. While the present disclosure contemplates the safe and effective use of ablation devices having a configuration similar to that shown in Figure 29, Figure 29 shows that such devices may induce high current densities at the surfaces of the electrodes 2202, 2204 and near the surface of the tissue 2200 between the electrodes 2202, 2204. As a result, the effective ablation volume 2206 may be limited, such as, but not limited to, near the surface of the tissue 2200.

[0109] FIG. 30 illustrates a cross-sectional view of exemplary current densities within target tissue 2300 induced 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, the electrode arrangement configuration illustrated in FIG. 30 may be generally similar to that illustrated in FIG. 12 and described above. As shown in FIG. 30 and compared to the current densities illustrated in FIG. 29, this exemplary device induces a generally lower current density near the surface of the tissue 2300, allowing for generally deeper penetration of the current density. As a result, the effective ablation volume 2314 may be larger and / or extend deeper into the tissue 2300. Generally, for some embodiments in accordance with at least some aspects of the present disclosure, a greater width between the electrodes 2302 and 2304 may induce deeper ablation, to some extent. If the electrodes are too far apart, the current density may be too low to heat the tissue sufficiently. For example, to achieve a tissue ablation depth of about 5-15 mm, the width between the outermost points on the two outer electrodes (e.g., those with the greatest voltage difference) may be between about 10 mm and about 30 mm when operating at a power of about 10 W to about 50 W and AC of about 400 kHz to about 450 kHz, with some six-electrode configurations similar to those shown in Figures 9-14.

[0110] Figure 31 illustrates a cross-sectional view of an exemplary electrical potential within target tissue 2400 caused by an exemplary ablation device including an electrode arrangement 2402 generally similar to that shown in Figure 10, and Figure 32 illustrates a cross-sectional view of an exemplary temperature profile within target tissue 2400 caused by an exemplary ablation device including an electrode arrangement 2402 generally similar to that shown in Figure 10, all in accordance with at least some aspects of the present disclosure. Generally, compared to embodiments including a two-electrode bipolar ablation device, electrical potential and temperature fluctuations are substantially more uniformly distributed in the target tissue. That is, in a two-electrode bipolar ablation device, electrical potential and / or temperature fluctuations may be more concentrated, such as near the electrodes, compared to an electrode arrangement 2402 generally similar to that shown in Figure 10.

[0111] 33A-33C illustrate alternative exemplary electrode arrangement configurations including generally rectangular electrodes arranged in a generally rectangular array. These electrode arrangement configurations may be generally similar in structure and operation to other electrode arrangement configurations and associated components described herein, and repeated descriptions of similar structure and operation have been omitted for the sake of brevity.

[0112] 33A is a simplified bottom view of an exemplary electrode arrangement configuration 3300 according to at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement configuration 3300 includes first and second electrodes 3302, 3304 that are relatively wide (e.g., about 4 mm) and four intermediate electrodes 3306, 3308, 3310, 3312 that are relatively narrow (e.g., about 1.5 mm). The spacing between the electrodes 3302, 3304, 3306, 3308, 3310, 3312 may be uniform at about 0.2 mm. The electrode arrangement configuration 3300 may have a length of about 8 mm.

[0113] 33B is a simplified bottom view of an exemplary electrode arrangement configuration 3330 according to at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement configuration 3330 includes first and second electrodes 3332, 3334 that are relatively wide (e.g., about 4 mm) and four intermediate electrodes 3336, 3338, 3340, 3342 that are relatively narrow (e.g., about 1.5 mm). The spacing between the electrodes 3332, 3334, 3336, 3338, 3340, 3342 may be uniform at about 0.5 mm. The electrode arrangement configuration 3330 may have a length of about 25 mm.

[0114] 33C is a simplified bottom view of an exemplary electrode arrangement configuration 3360 according to at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement configuration 3360 includes first and second electrodes 3362, 3364 that are relatively wide (e.g., about 6 mm) and four intermediate electrodes 3366, 3368, 3370, 3372 that are relatively narrow (e.g., about 0.5 mm). The spacing between the electrodes 3362, 3364, 3366, 3368, 3370, 3372 may be uniform at about 0.1 mm. The electrode arrangement configuration 3360 may have a length of about 25 mm.

[0115] 34A-34C illustrate alternative exemplary electrode arrangement configurations, including nested, generally circular arrays and / or annular ring electrodes. These electrode arrangement configurations may generally be similar in structure and operation to other electrode arrangement configurations and associated components described herein, and repeated descriptions of similar structure and operation have been omitted for the sake of brevity.

[0116] 34A is a simplified bottom view of an exemplary 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., approximately 4 mm) outer annular electrode 3402, a relatively wide (e.g., approximately 7 mm) circular inner electrode 3404, and four relatively narrow (e.g., approximately 1.5 mm) intermediate electrodes 3406, 3408, 3410, 3412 disposed therebetween. In this embodiment, the electrodes 3402, 3404, 3406, 3408, 3410, 3412 are arranged concentrically, and the spacing between the electrodes 3402, 3404, 3406, 3408, 3410, 3412 may be uniform at approximately 0.2 mm. The electrode arrangement 3400 may have an overall diameter of approximately 29 mm.

[0117] 34B is a simplified bottom view of an exemplary electrode arrangement 3420, according to at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3420 includes a relatively wide (e.g., approximately 4 mm) outer annular electrode 3422 spaced approximately 5-6 mm from a relatively wide (e.g., approximately 15.6 mm) circular inner electrode 3424, and two relatively narrow (e.g., approximately 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 approximately 1:2. In this embodiment, the electrodes 3422, 3424, 3426, 3428 are arranged concentrically, and the spacing between the electrodes 3422, 3424, 3426, 3428 may be uniform at approximately 0.2 mm. The electrode arrangement 3420 may have an overall diameter of approximately 34.8 mm.

[0118] 34C is a simplified bottom view of an exemplary electrode arrangement 3460, according to at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3460 includes a relatively wide (e.g., approximately 4 mm) outer annular electrode 3462, a relatively wide (e.g., approximately 15.6 mm) annular inner electrode 3464 having a central opening 3466 (e.g., approximately 4 mm), and two relatively narrow (e.g., approximately 2.5 mm) middle electrodes 3468, 3470 disposed therebetween. In this embodiment, the electrodes 3442, 3444, 3446, 3448 are arranged concentrically, and the spacing between the electrodes 3442, 3444, 3446, 3448 may be uniform at approximately 0.2 mm. The electrode arrangement 3440 may have an overall diameter of approximately 34.8 mm.

[0119] 35A-35D illustrate alternative exemplary electrode arrangement configurations including nested, generally oval-shaped ring electrodes. These electrode arrangement configurations may generally be similar in structure and operation to other electrode arrangement configurations and associated components described herein, and repeated descriptions of similar structure and operation have been omitted for the sake of brevity.

[0120] 35A is a simplified bottom view of an exemplary electrode arrangement 3500 according to at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3500 includes a relatively long (e.g., approximately 4 mm) outer elliptical electrode 3502, a relatively long (e.g., approximately 16.4 mm) elliptical inner electrode 3504, and four relatively narrow (e.g., approximately 1.5 mm) middle electrodes 3506, 3508, 3510, 3512 disposed therebetween. In this embodiment, the electrodes 3502, 3504, 3506, 3508, 3510, 3512 are arranged concentrically, and the spacing between the electrodes 3502, 3504, 3506, 3508, 3510, 3512 may be a uniform length of approximately 0.2 mm. In the width direction, the electrodes and the spacing between the electrodes 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.

[0121] 35B is a simplified bottom view of an exemplary electrode arrangement 3520, according to at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3520 includes a relatively long (e.g., approximately 4 mm) outer oval electrode 3522 and a relatively long (e.g., approximately 29.4 mm) oval inner electrode 3524, which may be arranged concentrically and spaced apart lengthwise by approximately 0.5 mm. In the widthwise 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 approximately 38.4 mm and an overall width of approximately 19.2 mm.

[0122] 35C is a simplified bottom view of an exemplary electrode arrangement configuration 3540, according to at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement configuration 3540 includes the same dimensions as the electrode arrangement configuration 3500 of FIG. 35A, except that all dimensions are multiplied by 1.25.

[0123] 35D is a simplified bottom view of an exemplary electrode arrangement configuration 3580 according to at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement configuration 3580 includes a relatively long (e.g., approximately 4 mm) outer oval electrode 3582, a relatively long (e.g., approximately 18 mm) oval inner electrode 3584, and two relatively narrow (e.g., approximately 3 mm) middle electrodes 3586, 3588 disposed therebetween. In this embodiment, the electrodes 3582, 3584, 3586, 3588 are arranged concentrically, and the spacing between the electrodes 3582, 3584, 3586, 3588 may be uniform at approximately 0.3 mm. In the width direction, the electrodes and electrode spacing are uniformly divided (scaled) by the same factor of 2. The electrode arrangement configuration 3580 may have an overall length of approximately 39.8 mm and an overall width of approximately 19.9 mm.

[0124] 36A-36H illustrate alternative exemplary electrode arrangements including nested, generally stadium-shaped ring electrodes. As used herein, "stadium-shaped" may describe a generally rectangular shape with semicircular opposing short ends. These electrode arrangements may generally be similar in structure and operation to other electrode arrangements and associated components described herein, and repeated descriptions of similar structure and operation have been omitted for the sake of brevity.

[0125] 36A is a simplified bottom view of an exemplary electrode arrangement 3600 according to at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3600 includes a relatively long (e.g., approximately 4 mm) outer stadium-shaped electrode 3602, a relatively long (e.g., approximately 19.4 mm) stadium-shaped inner electrode 3604 having a relatively narrow width (e.g., approximately 3 mm), and four relatively narrow (e.g., approximately 0.2 mm) middle electrodes 3606, 3608, 3610, 3612 disposed therebetween. In this embodiment, the electrodes 3602, 3604, 3606, 3608, 3610, 3612 are arranged concentrically, and the spacing between the electrodes 3602, 3604, 3606, 3608, 3610, 3612 may be uniform at approximately 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.

[0126] 36B is a simplified bottom view of an exemplary electrode arrangement 3620 according to 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) middle electrodes 3626, 3628, 3630, 3632 disposed therebetween. In this embodiment, the electrodes 3622, 3624, 3626, 3628, 3630, 3632 are arranged concentrically, and the spacing between the electrodes 3622, 3624, 3626, 3628, 3630, 3632 may be uniform at 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.

[0127] 36C is a simplified bottom view of an exemplary electrode arrangement 3640 according to 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 wide width (e.g., about 4 mm), and four relatively narrow (e.g., about 0.2 mm) middle electrodes 3646, 3648, 3650, 3652 disposed therebetween. In this embodiment, the electrodes 3642, 3644, 3646, 3648, 3650, 3652 are arranged concentrically, and the spacing between the electrodes 3642, 3644, 3646, 3648, 3650, 3652 may be uniform at 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.

[0128] 36D is a simplified bottom view of an exemplary electrode arrangement 3660 according to 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) middle electrodes 3666, 3668, 3670, 3672 disposed therebetween. In this embodiment, the electrodes 3662, 3664, 3666, 3668, 3670, 3672 are arranged concentrically, and the spacing between the electrodes 3662, 3664, 3666, 3668, 3670, 3672 may be uniform at 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.

[0129] 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 a relatively wide (e.g., approximately 1.5 mm) outer stadium-shaped electrode 3682, a relatively long (e.g., approximately 19.6 mm) stadium-shaped inner electrode 3684 having a relatively narrow width (e.g., approximately 4.5 mm), and two relatively narrow (e.g., approximately 0.1 mm) middle electrodes 3686, 3688 disposed therebetween. In this embodiment, the electrodes 3682, 3684, 3686, 3688 are arranged concentrically, and the spacing between the electrodes 3682, 3684, 3686, 3688 may be uniform at approximately 0.2 mm. The electrode arrangement 3680 may have an overall length of approximately 24 mm and an overall width of approximately 8.9 mm.

[0130] 36F is a simplified bottom view of an exemplary electrode arrangement 3700 according to at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3700 includes a relatively wide (e.g., approximately 1 mm) outer stadium-shaped electrode 3702, a relatively long (e.g., approximately 19.2 mm) stadium-shaped inner electrode 3704 having a relatively narrow width (e.g., approximately 3 mm), and two relatively narrow (e.g., approximately 0.4 mm) middle electrodes 3706, 3708 disposed therebetween. In this embodiment, the electrodes 3702, 3704, 3706, 3708 are arranged concentrically, and the spacing between the electrodes 3702, 3704, 3706, 3708 may be uniform at approximately 0.2 mm. The electrode arrangement 3700 may have an overall length of approximately 24 mm and an overall width of approximately 7.8 mm.

[0131] 36G is a simplified bottom view of an exemplary electrode arrangement 3720, according to at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3720 includes a relatively wide (e.g., approximately 2 mm) outer stadium-shaped electrode 3722, a relatively long (e.g., approximately 19.2 mm) stadium-shaped inner electrode 3724 having a relatively narrow width (e.g., approximately 3 mm), and two relatively narrow (e.g., approximately 0.4 mm) middle electrodes 3726, 3728 disposed therebetween. In this embodiment, the electrodes 3722, 3724, 3726, 3728 are arranged concentrically, and the spacing between the electrodes 3722, 3724, 3726, 3728 may be uniform at approximately 0.2 mm. The electrode arrangement 3720 may have an overall length of approximately 26 mm and an overall width of approximately 9.8 mm.

[0132] 36H is 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 a relatively wide (e.g., approximately 4 mm) outer stadium-shaped electrode 3742, a relatively long (e.g., approximately 23.6 mm) stadium-shaped inner electrode 3744 having a relatively wide width (e.g., approximately 9 mm), and two relatively wide (e.g., approximately 3 mm) middle electrodes 3746, 3748 disposed therebetween. In this embodiment, the electrodes 3742, 3744, 3746, 3748 are arranged concentrically, and the spacing between the electrodes 3742, 3744, 3746, 3748 may be uniform at approximately 0.2 mm. The electrode arrangement 3740 may have an overall length of approximately 44.8 mm and an overall width of approximately 21.2 mm.

[0133] 37A-37D illustrate alternative exemplary electrode arrangement configurations, including truncated, nested, generally circular (or part-circular) and / or annular (or semi-annular) ring electrodes. These electrode arrangement configurations may generally be similar in structure and operation to other electrode arrangement configurations and associated components described herein, and repeated descriptions of similar structure and operation have been omitted for the sake of brevity.

[0134] 37A is a simplified bottom view of an exemplary electrode arrangement 3800 according to at least some aspects of the present disclosure. In the illustrated embodiment, the electrode arrangement 3800 includes opposing, mirror-image segments (e.g., semi-annular segments) of relatively wide (e.g., approximately 4 mm) outer annular electrodes 3802A, 3802B spaced about 5-6 mm from a segment of a relatively long (e.g., approximately 15.6 mm) circular inner electrode 3804, and opposing, mirror-image segments (e.g., semi-annular segments) of two relatively narrow (e.g., approximately 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 area of ​​the outer electrodes 3802A, 3802B is approximately 2:1. In this embodiment, the electrodes 3802A, 3802B, 3804, 3806A, 3806B, 3808A, 3808B are arranged concentrically and the spacing between the electrodes 3802A, 3802B, 3804, 3806A, 3806B, 3808A, 3808B may be uniform at about 0.2 mm. The electrode arrangement 3800 may have a total length of about 34.8 mm and a width of about 9 mm.

[0135] 37B is a simplified bottom view of an exemplary electrode arrangement 3820 according to 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., approximately 4 mm) outer annular electrodes 3822A, 3822B spaced approximately 5-6 mm from a segment of a relatively long (e.g., approximately 15.6 mm) circular inner electrode 3824, and opposing, mirror-image segments of two relatively narrow (e.g., approximately 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 area of ​​the outer electrodes 3822A, 3822B is approximately 1.4:1. In this embodiment, the electrodes 3822A, 3822B, 3824, 3826A, 3826B, 3828A, 3828B are arranged concentrically and the spacing between the electrodes 3822A, 3822B, 3824, 3826A, 3826B, 3828A, 3828B may be uniform at about 0.2 mm. The electrode arrangement 3820 may have a total length of about 34.8 mm and a width of about 15 mm.

[0136] 37C is a simplified bottom view of an exemplary electrode arrangement 3840, according to 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, 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 middle electrodes 3846A, 3846B, 3848A, 3848B disposed therebetween. In this embodiment, the electrodes 3842A, 3842B, 3844, 3846A, 3846B, 3848A, 3848B are arranged concentrically and the spacing between the electrodes 3842A, 3842B, 3844, 3846A, 3846B, 3848A, 3848B may be uniform at about 0.2 mm. The electrode arrangement 3840 may have a total length of about 34.8 mm and a width of about 20 mm.

[0137] FIG. 37D is a simplified bottom view of an exemplary electrode arrangement configuration 3860, according to at least some aspects of the present disclosure. Unlike the generally straight, parallel truncated embodiments of FIGS. 37A, 37B, and 37C, the embodiment of FIG. 37D is truncated to form a bowtie shape. That is, the end portions have a greater width than the central portion. In the illustrated embodiment, the electrode arrangement configuration 3860 includes opposing, mirror-image segments of relatively wide (e.g., approximately 4 mm) outer annular electrodes 3862A, 3862B spaced about 5-6 mm from a segment of a relatively long (e.g., approximately 15.6 mm) circular inner electrode 3864, and opposing, mirror-image segments of two relatively narrow (e.g., approximately 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 area of ​​the outer electrodes 3862A, 3862B is approximately 1:1. In this embodiment, the electrodes 3862A, 3862B, 3864, 3866A, 3866B, 3868A, 3868B are arranged concentrically, and the spacing between the electrodes 3862A, 3862B, 3864, 3866A, 3866B, 3868A, 3868B may be uniform at approximately 0.2 mm. The electrode arrangement 3860 may have an overall length of approximately 34.8 mm and an overall width of approximately 24 mm. A narrower, central portion may have a width of approximately 15 mm.

[0138] FIG. 38A is a bottom view of an exemplary electrode arrangement 3880 including a semiconductor electrode disposed between two outer electrodes, and FIG. 38B is a simplified elevation view of the embodiment of FIG. 38A , all according to 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 in a spaced-apart, generally parallel arrangement on and in electrical contact with a semiconductor substrate 3886. Thus, the tissue-contacting 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. While the illustrated embodiment includes two electrodes 3882, 3884, it will be understood that any of the electrode arrangements described herein may be fabricated in a similar manner with semiconductor material disposed in the gap between the electrodes. In the illustrated embodiment, the first outer electrode 3882 includes a first tissue contacting location 114A, the semiconductor substrate 3886 includes an intermediate tissue contacting location 114B, and the second outer electrode 3884 includes a second tissue contacting location 114C.

[0139] 39 is a simplified elevational view of an exemplary electrode arrangement 3900 including a semiconductor electrode including a semiconductor layer disposed on a metal conductor, in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the 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 forms a tissue-contacting surface 3916 and can act as an electrode. For example, the semiconductor layer 3914 can be applied as a coating and / or film, which can be electrically coupled to the conductors 3902, 3904, 3906, 3908, 3910, 3912. In the illustrated embodiment, the semiconductor layer 3914 includes a first tissue-contacting location 114A, an intermediate tissue-contacting location 114B, and a second tissue-contacting location 114C.

[0140] FIG. 40 is a simplified elevational view of an exemplary electrode arrangement 4000 including a semiconductor electrode having conductors embedded therein, in accordance with at least some aspects of the present disclosure. In the illustrated embodiment, the first conductor 4002 and the second conductor 4004 are arranged in a spaced-apart, generally parallel arrangement generally similar to the embodiment illustrated in FIGS. 38A and 38B . However, in the embodiment of FIG. 40 , the conductors 4002, 4004 may be embedded within a semiconductor substrate 4006. Thus, the tissue-contacting surface 4008 of the electrode arrangement 4000 includes the semiconductor substrate 4006, which acts as an electrode without the conductors 4002, 4004 being exposed at the tissue-contacting surface 4008. In the illustrated embodiment, the semiconductor substrate 4006 includes a first tissue-contacting location 114A, an intermediate tissue-contacting location 114B, and a second tissue-contacting location 114C.

[0141] In some exemplary embodiments including a tissue contacting surface comprising a semiconductor material, the semiconductor material may be directly electrically connected to one or more conductors configured to deliver ablation energy. In some exemplary embodiments including a tissue contacting surface comprising a semiconductor material, the semiconductor material may be electrically insulated from at least one conductor configured to deliver ablation energy. In some exemplary embodiments including a tissue contacting surface comprising a semiconductor material, the semiconductor material may include one or more gaps or notches therein that may at least partially electrically insulate at least one portion of the semiconductor material from another portion of the semiconductor material. In some exemplary embodiments including a tissue contacting surface comprising a semiconductor material, the semiconductor material may have a uniform shape. In some exemplary embodiments including a tissue contacting surface comprising a semiconductor material, the semiconductor material may have a non-uniform shape.

[0142] 41 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 middle 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 produces asymmetric ablation with higher temperatures 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 another. Similar asymmetries may be utilized with any of the embodiments described herein, including rectangular arrays, concentric arrays, etc.

[0143] 42 is a simplified bottom view illustrating variable dimensions of a rectangular electrode array 5050. In the illustrated embodiment, the electrode arrangement configuration 5050 includes relatively wide outer electrodes 5052, 5054 and four relatively narrow middle electrodes 5056, 5058, 5060, 5062 disposed therebetween. The outer electrodes 5052, 5054 have a width 5064 and are separated by a separation distance 5066. The array 5050 has a length 5068.

[0144] In some exemplary embodiments, the width of the outer electrode may be about 2-6 mm. In some configurations, an outer electrode width greater than about 8 mm may result in an excessively low current density at the electrode, which may result in weak ablation. In some configurations, an outer electrode width less than about 2 mm may result in an excessively high current density at the electrode, which may result in excessively strong ablation.

[0145] In some exemplary embodiments, such as those having an outer electrode width of approximately 2-6 mm, the separation distance 5066 may be approximately 2-8 mm. In some configurations, a separation distance that is too small may cause excessive current density and / or overheating in the center between the electrodes. A spacing that is too large may cause bimodal current density and / or underheating in the center between the electrodes.

[0146] Generally, the presence of the intermediate electrodes 5056, 5058, 5060, 5062 reduces the current density near the tissue surface, thereby reducing overheating near the tissue surface. In general, the length 5068 can be varied at will, although it can be advantageous to adjust the power density accordingly.

[0147] 43 is a simplified bottom view illustrating dimensions of a concentric electrode array 6000 that may vary. In the illustrated embodiment, the electrode arrangement 6000 includes opposing, mirror-image segments of relatively wide outer annular electrodes 6002A, 6002B, a segment of a relatively wide circular inner electrode 6004, and opposing, mirror-image segments of two relatively narrow annular middle electrodes 6006A, 6006B, 6008A, 6008B disposed therebetween. The outer electrodes 6002A, 6002B have a width 6010 and are separated by a separation distance 6012. The array 6000 has a length 6014. The width 6010 and separation distance 6012 may generally vary as described above with reference to the rectangular electrode arrangement 5050.

[0148] In general, the presence of the intermediate electrodes 6006A, 6006B, 6008A, 6008B tends to increase the effective depth of ablation, such as due to the current density being concentrated near the central region. In general, the length 6014 can be varied arbitrarily, although it may be advantageous to adjust the power density accordingly.

[0149] In some exemplary embodiments, the power density of the applied ablation energy can be selected to provide consistent ablation. As used herein, "power density" may refer to the ratio of the applied power to the surface area of ​​the outermost electrode. For example, about 0.05 W / mm 2 Power densities below about 0.05-0.5 W / mm 2 may generally heat the target tissue more slowly than desired. 2 A power density of about 0.5 W / mm can generally produce desirable ablation results. 2 Higher power densities generally can overheat the target tissue.

[0150] In some exemplary embodiments, such as those comprising one inner electrode 6004 and two outer electrodes 6002A, 6002B, the ratio of the surface area of ​​the inner electrode 6004 to the surface area of ​​the outer electrodes 6002A, 6002B can be from about 0.3:1 to about 3:1. In some configurations, a ratio less than about 0.3:1 can tend to concentrate ablation energy in the inner electrode. In some configurations, a ratio greater than about 3:1 can concentrate ablation energy in the outer electrode.

[0151] 1A-1E , an exemplary method of forming a lesion 118 in a target tissue 116 may include one or more of the following operations in any order: The tissue engaging portion 114 of the end effector 102 of the ablation device 100 may be positioned near the target tissue 116 such that a first tissue contacting location 114A of the tissue engaging portion 114 is in electrical contact with the target tissue 116, an intermediate tissue contacting location 114B of the tissue engaging portion 114 is in electrical contact with the target tissue 116, and a second tissue contacting location 114C is in electrical contact with the target tissue 116. The lesion 118 may be formed in the target tissue 116 by applying electrical ablation energy to the end effector 102 such that the magnitude of at least one electrical parameter differs among the first tissue contacting location 114A, the intermediate tissue contacting location 114B, and the second tissue contacting location 114C, and the magnitude of the intermediate tissue contacting location is between the magnitude of the first tissue contacting location and the magnitude of the second tissue contacting location.

[0152] In some embodiments, electrical ablation energy may be applied to a discrete first electrode 110a that includes a first tissue contacting location 114A and a discrete second electrode 110f that includes a second tissue contacting location 114C. In some embodiments, electrical ablation energy may be applied to discrete intermediate electrodes 110b, 110c, 110d, 110e that include an intermediate tissue contacting location 114B. In some embodiments, the intermediate electrodes 110b, 110c, 110d, 110e include at least two sequentially arranged, discrete intermediate electrodes 110b, 110c, 110d, 110e, and electrical ablation energy can be applied to the at least two sequentially arranged, discrete intermediate electrodes 110b, 110c, 110d, 110e such that the magnitude of at least one electrical parameter incrementally differs between the at least two sequentially arranged, discrete intermediate electrodes 110b, 110c, 110d, 110e.

[0153] In some embodiments, such as in Figures 38A and 38B, electrical ablation energy can be applied to semiconductor elements 3886 that include intermediate tissue contact locations.

[0154] In some embodiments, such as FIG. 40 , electrical ablation energy may be applied from an ablation energy source to a first conductor 4002 and a second conductor 4004, with the first conductor 4002 electrically coupled to a semiconductor element 4006 near the first tissue contact location 114A and the second conductor 4004 electrically coupled to a semiconductor element 4006 near the second tissue contact location 114C.

[0155] 39 , electrical ablation energy is applied to intermediate conductors 3906, 3908, 3910, 3912, which may be electrically coupled to semiconductor element 3914 near intermediate tissue contact location 114B. The magnitude of at least one electrical parameter varies among first conductor 3902, intermediate conductors 3906, 3908, 3910, 3912, and second conductor 3904, and the magnitude of the intermediate tissue contact location is between the magnitude of the first tissue contact location and the magnitude of the second tissue contact location.

[0156] In some embodiments, electrical ablation energy can be applied from the ablation source to the middle conductor through a first resistor R1 and from the second conductor through a second resistor R5.

[0157] In some embodiments, electrical ablation energy may be applied to a discrete first electrode 110a that includes a first tissue contacting location 114A and a discrete second electrode 110f that includes a second tissue contacting location 114C.

[0158] In some embodiments, the at least one electrical parameter can include electrical potential and / or current. In some embodiments, the electrical ablation energy can include radiofrequency electrical energy and / or pulsed field ablation electrical energy.

[0159] In some embodiments, ablation device 100 includes a shaft 104 disposed proximally on end effector 102, and tissue engaging portion 114 of end effector 102 of ablation device 100 can be positioned using shaft 104. In some embodiments, ablation device 100 includes a handle 106 disposed proximally on shaft 104, and tissue engaging portion 114 of end effector 102 of ablation device 100 can be positioned using handle 106. In some exemplary embodiments, ablation device includes at least one connecting element 108 configured to electrically couple end effector 102 to an external ablation energy source, and electrical ablation energy can be applied to end effector 102 via at least one connecting element 108.

[0160] Some exemplary embodiments configured for cardiac tissue ablation according to at least some aspects of the present disclosure may be configured to ablate target tissue greater than about 5.0 mm deep, such as 5.0-10.0 mm deep.

[0161] An exemplary embodiment including a first electrode, a second electrode, and four intermediate electrodes may be operated 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 W.

[0162] An exemplary procedure for forming a lesion between 3 mm and 15 mm in depth involves placing the smaller electrode arrangement configuration of Figure 10, 11, or 12 in firm contact with cardiac tissue, activating the energy source for 20 to 90 seconds under the conditions noted in the previous paragraph, and then turning off the energy source and removing the electrodes. A second exemplary procedure for forming a lesion between 3 mm and 15 mm in depth involves placing the larger electrode arrangement configuration of Figure 13A, 13B, or 14 in firm contact with cardiac tissue, activating the energy source for 40 to 300 seconds under the conditions noted in the previous paragraph, and then turning off the energy source and removing the electrodes.

[0163] In various exemplary embodiments according to at least some aspects of the present disclosure, the device may be configured to deliver energy to the target tissue in an ablation, microwave, pulsed electric field ablation, or radiofrequency manner, or any combination of any one or more of these. Exemplary radiofrequency manners include bipolar, monopolar, and / or multipolar manners. In these cases, the voltage, current, power, and frequency may differ from those described elsewhere in this disclosure.

[0164] Some exemplary embodiments according to at least some aspects of the present disclosure may be configured for use in procedures other than and / or in addition to tissue ablation, such as inspection procedures. For example, without limitation, some embodiments may be configured for electroporation, such as over relatively large areas for cardiac pacing and / or sensing and / or drug delivery. Some non-ablative procedures may be performed in conjunction with ablation procedures, such as to assess the necessity, placement, and / or effectiveness of one or more ablations. Furthermore, some ablation procedures may be performed in conjunction with non-ablative procedures, such as open ablation procedures, clip ablation procedures, and / or cryotherapy ablation procedures.

[0165] Although several exemplary embodiments are described above in the context of ablation of cardiac tissue, it will be appreciated that several alternative exemplary embodiments may be utilized for use in connection with other target tissues and anatomical locations. For example, without limitation, alternative exemplary embodiments may be configured for use with target tissue associated with a patient's brain, gastrointestinal tract, lungs, liver, skin, gynecological tract, esophageal tissue, and / or tissue associated with the mouth and / or nose.

[0166] It is within the scope of the present disclosure to perform electrosurgical (e.g., ablation) procedures using any suitable electrodes. For example, without limitation, 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 configurations, bull's-eye configurations, generally circular configurations, and / or generally elliptical configurations), or any combination thereof (e.g., one or more straight lines inside an ellipse). In some exemplary embodiments, one or more electrodes may have a three-dimensional configuration, such as a cup shape, a dome shape, a configuration that generally conforms to an anatomical structure, and / or a configuration custom-shaped for a particular anatomical structure. Other configurations may include a tiled matrix, an in-plane generally flat configuration, and / or an out-of-plane generally flat configuration. Some exemplary electrodes may take the form of discrete electrodes. Some exemplary electrodes may take the form of continuous electrodes, such as semiconductor electrodes, thin-film conductors with various applied voltages, and / or conductive fluids.

[0167] Some exemplary embodiments according to at least some aspects of the present disclosure are configured to simultaneously control multiple variables to achieve desired performance during operation, where such coupled variables may include, for example, electrode power, applied pressure to the inflatable device, applied vacuum to the suction device, and / or a function of temperature resulting from ablation or from a secondary heating or cooling source over time.

[0168] Some exemplary embodiments according to at least some aspects of the present disclosure may be configured to address thermal considerations associated with operation. For example, some embodiments may be configured to actively and / or passively remove excess heat and / or may be controlled to operate at a desired temperature. Some exemplary embodiments may include a cooling element, such as a heat pipe, that may be disposed near the electrodes, such as between the electrodes. Some exemplary embodiments may utilize system-level cooling, such as coolant pumped around and / or through the electrodes and / or tissue contacting surfaces. Some exemplary embodiments may utilize electrode-level cooling, such as coolant pumped behind the electrodes. Some exemplary embodiments may utilize passive cooling, such as one or more heat sinks disposed behind the electrodes. Some exemplary embodiments may include more than two electrodes configured to operate in conjunction. For example, any number of electrodes may be configured for phased / switched groups.

[0169] It is within the scope of the present disclosure to control electrical parameters associated with individual electrodes in any suitable manner. For example, without limitation, various devices according to at least some aspects of the present disclosure may be configured to deliver electrical energy to one or more electrodes at a selected potential (voltage), current, and / or power. In some exemplary embodiments, some electrical parameters may be configured for passive control, such as by using a resistor bank (e.g., a resistive voltage divider), a capacitor bank, and / or an inductor bank. In some exemplary embodiments, some electrical parameters may be configured for active control, such as individual electrode control, a switch box configuration (e.g., one generator powering multiple electrodes with active switching), multiple generators, and / or active monitoring and parameter adjustment. Some exemplary embodiments may include control arrangements that utilize feedback, such as feedback related to current, power, impedance, inductance, capacitance, temperature (e.g., tissue temperature), and / or time.

[0170] While certain exemplary embodiments are described above, it is within the scope of this disclosure to configure the device in a variety of alternative forms. For example, without limitation, some exemplary devices may include elements that are malleable, flexible (e.g., bend in one plane, bend in two planes, etc.), and / or rigid. Some exemplary devices may include elements configured for rolling and / or folding, such as rolling along a minor axis and / or rolling along a major axis.

[0171] It is within the scope of this disclosure to utilize various methods of fixation in connection with exemplary embodiments. For example, without limitation, some exemplary devices may be configured to utilize manual fixation (e.g., operator-applied mechanical load), vacuum fixation, clamping, and / or magnetic coupling to hold the end effector against the target tissue. See, e.g., the discussion above with reference to Figures 2 and 3.

[0172] It is within the scope of the present disclosure to utilize end effectors having various shapes. For example, without limitation, some exemplary end effectors may be contoured and / or include electrodes generally disposed on the interior and / or exterior. In some exemplary embodiments, the electrodes may be generally round, ring-shaped, provided as a jacket or collar, generally tubular or cylindrical (e.g., full radius and / or partial radius).

[0173] It is within the scope of the present disclosure to utilize an end effector that includes an expandable element. In some exemplary embodiments, a component that includes an expandable element can be configured to conform to adjacent structures (e.g., anatomical structures). In some exemplary embodiments, a component that includes an expandable element can be configured to have a predetermined, generally fixed shape. See, for example, the discussion above with reference to FIGS. 4, 19, and 23.

[0174] It is within the scope of this disclosure to perform the procedure with any suitable access approach. For example, endocardial access may be obtained using a percutaneous approach (e.g., arterial and / or venous) and / or surgical approach (e.g., apical, femoral-femoral bypass (venous), femoral-femoral bypass (arterial), conventional bypass cannula (arterial), conventional bypass cannula (venous), and / or atriotomy). Epicardial access may be obtained using a percutaneous approach (e.g., subxiphoid) and / or surgical approach (e.g., lateral (right or left), surgical window, and / or sternotomy (complete or partial)), and / or minimally invasive surgical approach (MIS). It will be understood that the above list is merely exemplary and is not to be considered limiting.

[0175] It is within the scope of this disclosure to perform procedures involving any portion of the heart using the devices and / or methods disclosed herein. For example, procedures involving the right atrium may be performed in connection with the treatment of inappropriate sinus tachycardia (e.g., ridge, inferior vena cava, and / or superior vena cava), atrial fibrillation (e.g., Coz Maze lesions—right-sided), supraventricular tachycardia, and / or Wolff-Parkinson-White syndrome. Procedures involving the right ventricle may be performed in connection with the treatment of ventricular tachycardia (e.g., linear or spot lesions) (e.g., right ventricular posterior wall, right ventricular lateral free wall, right ventricular anterior wall, septum, right ventricular papillary muscles, and / or right ventricular outflow tract), partial ventricular contraction (e.g., right ventricular outflow tract septum, right ventricular base, and / or right ventricular outflow tract free wall), and / or Brugada syndrome (e.g., right ventricular outflow tract). Procedures involving the left atrium may be performed in connection with the treatment of atrial fibrillation (e.g., surrounding or linear lesions) (e.g., to the ligament of Marshall, atrial roof and floor, left atrial posterior wall, isthmus, and / or autonomic nerves (ganglionic plexus)), supraventricular tachycardia, and / or left atrial appendage isolation (e.g., left atrial appendage opening). Procedures involving the left ventricle may be performed in connection with, for example, syncope (e.g., autonomic (ganglionic plexus)), atrial tachycardia (e.g., anywhere in the left ventricle), atrial flutter (e.g., mitral valve), Wolff-Parkinson-White syndrome (e.g., atrioventricular groove), partial ventricular contractions (e.g., left ventricular outflow tract and / or aortic root), hypertension (e.g., anywhere in the left ventricle), Brugada and / or ventricular tachycardia (e.g., linear or spot lesions) (e.g., left ventricular posterior wall, left ventricular lateral free wall, left ventricular anterior wall, septum, left ventricular papillary muscles, and / or left ventricular apex). Procedures involving the right ventricle / left ventricular septum may be performed in connection with ventricular tachycardia (e.g., combined right and left ventricular lesions). Procedures involving the right atrium / left atrial septum may also be performed. It will be understood that the above list is merely exemplary and is not to be considered limiting.

[0176] The present disclosure contemplates that ablation systems configured to perform pulsed electric field ablation (“PFA”) may be used in a variety of medical and surgical procedures. Generally, PFA systems may be used to ablate targeted cells while limiting potential collateral damage to non-target tissue. PFA typically involves applying high-voltage electrical pulses to targeted tissue. The pulses generate high-intensity electric fields, disrupting the integrity of cell membranes in the targeted tissue. As a result, over a short period of time (e.g., days to weeks), cells die and lesions form in the targeted tissue. The present disclosure contemplates that PFA may be used to ablate cardiac tissue for the treatment of cardiac arrhythmias. Generally, any ablation device according to at least some aspects of the present disclosure may be utilized in conjunction with radiofrequency, pulsed electric field ablation, and / or any other electrical ablation modality.

[0177] Some exemplary embodiments according to at least some aspects of the present disclosure may be configured without a heat sink and / or without active cooling (e.g., open-circuit or closed-circuit liquid cooling). Some exemplary embodiments, such as those configured for bipolar operation, may be configured without a unipolar ground (e.g., a return electrode).

[0178] As used herein, in the claims, the inclusion of "or" as used in a list of items (e.g., a list of items followed by phrases such as "at least one of" or "one or more of") indicates an inclusive list, such as, for example, a list of [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).

[0179] As will now be appreciated by those skilled in the art, depending on the particular use of the present application at hand, many modifications, substitutions, and changes may be made in and to the materials, arrangements, constructions, and methods of use of the devices of the present disclosure without departing from the spirit and scope thereof. In light of this, the scope of the present disclosure should not be limited to the scope of the specific embodiments illustrated and described herein, which are merely some examples, but rather should be consistent with the full scope of the following appended claims and their functional equivalents. [Explanation of symbols]

[0180] 14 shaft 100 Ablation Devices 102 End Effector 106 Handle 108 Cable 110 electrodes 110a, 110b, 110c, 110d, 110e, and 110f electrodes 112 Insulator 114 Tissue-Engaging Portion or Working Surface 114A First tissue contact position 114B Intermediate tissue contact position 114C Third tissue contact position 116 Organization 118 tissue ablation areas 120 Organizational Area 124 Thermal Conductor 126 Adhesive or thermal bonding processes 128 Electrical Insulators 128 Polyimide film 130 Silicone Insulator 132 Filled Elastomer 134 Thermal Conductor 200 Suction line 202 Opening 204 Gap 206 Hard Shell 208 Soft Edge 300 Proximal jaw 302 Distal jaw 306 Closure Trigger 308 Ablation Sensing Unit (ASU) Generator 400 Expandable Member 500a circular electrode 500b~f ring 600a, 600b Inner electrode or resistive conductor (e.g., semiconductor electrode) 700 Pacing Monitor 702 Impedance Monitoring System 704 Interconnector 706 Switch 708 Electrocardiogram measuring device

Claims

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

2. The tissue ablation device of claim 1 , wherein the end effector comprises a radiofrequency pen.

3. The tissue ablation device of claim 1 , wherein the end effector comprises a radiofrequency clamp.

4. The tissue ablation device of claim 1 , wherein the end effector comprises a radiofrequency pen or pod with vacuum suction.

5. The tissue ablation device of claim 1 , wherein the end effector comprises an expandable device.

6. The tissue ablation device of claim 5 , wherein the expandable device includes an inflatable element.

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

8. 8. The tissue ablation device of claim 7, wherein the widths of the first and second electrodes are between 2 mm and 8 mm, the width of the intermediate electrode is smaller than the first and second electrodes, and the total width having a maximum potential difference is between 10 mm and 30 mm.

9. The tissue ablation device of claim 8 , wherein the lengths of the plurality of electrodes are configured to form a desired ablation length.

10. The tissue ablation device of claim 1 , wherein the plurality of electrodes comprises three or more electrodes.

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

12. The tissue ablation device of claim 1 , wherein the first electrode, the second electrode, and the intermediate electrode are distributed in an annular fashion, each electrode being concentric with respect to an adjacent electrode.

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

14. The tissue ablation device of claim 1 , wherein the current in each electrode is different from the current in adjacent electrodes.

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

16. The tissue ablation device of claim 1 , wherein the potential difference between adjacent electrodes is uniform or non-uniform.

17. 10. The tissue ablation device of claim 1, wherein the maximum potential difference is between 10 volts and 500 volts.

18. 18. The tissue ablation device of claim 17, wherein the maximum potential difference is between 30 and 80 volts.

19. 10. The tissue ablation device of claim 1, wherein the total power output is between 1 watt and 200 watts.

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

21. 10. The tissue ablation device of claim 1, wherein the applied frequency is between 50 kilohertz and 5,000 kilohertz.

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

23. 10. The tissue ablation device of claim 1, wherein multiple electrode arrays are disposed end-to-end on the tissue ablation device to extend the surface length of the ablated region while maintaining electrical and thermal energy to a width and depth within the ablated region.

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

25. The tissue ablation device of claim 1 , wherein the voltage and current of each of the first electrode and the second electrode is sinusoidal with respect to time.

26. The tissue ablation device of claim 1 , wherein the voltage and current of each of the first and second electrodes is a square wave with respect to time.

27. 10. The tissue ablation device of claim 1, wherein the intermediate electrode is electrically disconnected from the first electrode and the second electrode, the intermediate electrode conducting current between the first electrode and the second electrode and providing low resistance.

28. 1. A tissue ablation device for ablating tissue, comprising: an end effector having a tissue contacting surface; a power source coupled to the end effector; an array of electrodes in electrical communication with the tissue contact surface, each electrode in the array of electrodes being held at an electrical potential, current, or power as supplied by a voltage source, the electrical potential, current, or power of each electrode being different from the electrical potential, current, or power of an adjacent electrode, the array of electrodes being configured to ablate the tissue while distributing an electrical potential over a surface of the tissue, whereby the distribution of the electrical potential reduces temperature variations within the ablated tissue.

29. 1. A method for ablating tissue, comprising: positioning an end effector at a target site of the tissue, the end effector comprising a tissue contacting surface in electrical communication with an array of electrodes; applying an electrical potential, current, or power from a power source to each electrode in the array of electrodes, the array of electrodes comprising a distributed electrical potential and configured to ablate the tissue while distributing an electrical potential on the tissue; ablating the tissue at a distance from the end effector while minimizing heat applied to a surface of the tissue to create a more uniform and deeper ablation.

30. 1. An electrosurgical device comprising: a first electrode; a second electrode; and an intermediate electrical element; the first electrode, the second electrode, and the intermediate electrical element are configured to be in electrical communication with a target tissue; An electrosurgical device, wherein the intermediate electrical element is disposed 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 first electrode, the at least one intermediate electrode, and the second electrode are configured to deliver electrical energy to the target tissue; The electrosurgical device according to claim 31 , wherein at least one electrical parameter of the electrical energy is incrementally varied 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 an electrical 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. 1. An electrosurgical system comprising: The electrosurgical device of claim 30; a resistive voltage divider electrically connected to the first input conductor and the second input conductor, the resistive voltage divider including a first resistor and a second resistor; the first resistor and the second resistor are electrically connected in series between the first input conductor and the second input conductor; an electrosurgical system, wherein the first electrode is configured to electrically connect to a first input connector, the second electrode is configured to electrically connect to a second input connector, and at least one intermediate electrode is configured to electrically connect to at least one intermediate conductor electrically connected between the first resistor and the second resistor;

38. 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; the first input conductor and the second input conductor are configured to releasably electrically couple 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; The electrosurgical system according to claim 37, wherein the at least one intermediate electrode is electrically coupled to the at least one intermediate conductor.

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

40. the resistive voltage divider is disposed within the electrosurgical generator; the first input conductor is configured to releasably electrically couple to the first electrode; the second input conductor is configured to releasably electrically couple to the second electrode; The electrosurgical system according to claim 38, wherein the at least one intermediate conductor is configured to releasably electrically couple to the at least one intermediate electrode.

41. 1. An electrosurgical device comprising: a first electrode; a second electrode; and at least one intermediate electrical resistance element; the first electrode, the second electrode, and the at least one intermediate electrical resistive element are configured to be in electrical communication with a target tissue; An electrosurgical device, wherein the at least one intermediate electrical resistance element is disposed between the first electrode and the second electrode.

42. the at least one intermediate electrical resistance element includes a first electrical resistance element electrically connected to the first electrode and a second electrical resistance element electrically connected to the second electrode; The electrosurgical device according to claim 41 , wherein the first electrical resistance element is not directly electrically connected to the second electrical resistance element.

43. The electrosurgical device according to claim 42, wherein a gap is disposed between the first and second resistive elements.

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 electrical resistance element is electrically connected between the first electrode and the second electrode.

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

47. 1. An electrosurgical device comprising: a tissue contacting surface in electrical communication with the first electrode, the second electrode, and the plurality of intermediate electrodes; an electrical input connector; the first electrode and the second electrode are spaced apart by a first width; the plurality of intermediate electrodes are sequentially arranged between the first electrode and the second electrode along the first width, an electrosurgical device, wherein at least one electrical parameter varies among 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 respective 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 value varies incrementally between the first electrode, each intermediate electrode, and the second electrode.

49. 1. An ablation device for forming a lesion in a target tissue, comprising: An end effector, a tissue engaging portion configured to engage a target tissue, the tissue engaging portion configured to be in electrical contact with the target tissue and including a first tissue contacting portion, a second tissue contacting portion, and an intermediate tissue contacting portion; the intermediate tissue contact portion is disposed between the first tissue contact portion and the second tissue contact portion; An ablation device comprising an end effector, wherein the first tissue contact portion, the intermediate tissue contact portion, and the second tissue contact portion are electrically coupled, and when the end effector is supplied with electrical ablation energy, the magnitude of at least one electrical parameter differs among the first tissue contact portion, the intermediate tissue contact portion, and the second tissue contact portion, and 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. 50. The ablation device of claim 49, wherein the tissue engaging portion comprises a discrete first electrode that includes the first tissue contacting portion and a discrete second electrode that includes the second tissue contacting portion.

51. 51. The ablation device of claim 50, wherein the tissue engaging portion comprises a discrete intermediate electrode that includes the intermediate tissue contact portion.

52. 52. The ablation device of claim 51, wherein the tissue engaging portion comprises 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 intermediate electrodes include at least two sequentially arranged, discrete intermediate electrodes; 52. The ablation device of claim 51, wherein the magnitude of the at least one electrical parameter varies incrementally between the at least two sequentially disposed, discrete intermediate electrodes.

54. the first electrode, the intermediate electrode, and the second electrode are arranged in a line; 52. The ablation device of claim 51, wherein the first electrode is disposed as a first outermost electrode at a first end and the second electrode is disposed as a second outermost electrode at a second end.

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

56. 56. The ablation device of 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. 52. The ablation device of claim 51, wherein the intermediate electrode and the second electrode comprise nested, concentric, generally stadium-shaped ring electrodes disposed around the first electrode.

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

59. 59. The ablation device of claim 58, wherein the first electrode, the intermediate electrode, and the second electrode vary in at least one of width and length, and at least one of the first electrode, the intermediate electrode, and the second electrode can be divided into multiple segments.

60. 60. The ablation device of 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. 50. The ablation device of claim 49, wherein the tissue engaging portion comprises a semiconductor element that includes the intermediate tissue contact portion.

62. 62. The ablation device of claim 61, wherein the semiconductor element has a resistance greater than a resistance of the target tissue.

63. 62. The ablation device of claim 61, wherein the semiconductor element further comprises the first tissue contacting portion and the second tissue contacting portion.

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

65. 62. The ablation device of claim 61, wherein the end effector further comprises an intermediate conductor electrically coupled to the semiconductor element near the intermediate tissue contact portion.

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

67. the intermediate conductor is electrically coupled to the first conductor by a first resistor; 67. The ablation device of claim 66, wherein the intermediate conductor is electrically coupled to the second conductor by a second resistor.

68. 62. The ablation device of claim 61, wherein the tissue engaging portion comprises a discrete first electrode that includes the first tissue contacting portion and a discrete second electrode that includes the second tissue contacting portion.

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

70. 50. The ablation device of claim 49, wherein the at least one electrical parameter comprises an electrical potential.

71. 50. The ablation device of claim 49, wherein the at least one electrical parameter comprises electrical current.

72. 50. The ablation device of claim 49, wherein the electrical ablation energy comprises radiofrequency electrical energy.

73. 50. The ablation device of claim 49, wherein the electrical ablation energy comprises pulsed field ablation electrical energy.

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

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

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

77. 1. A method for creating a lesion in a target tissue, comprising: positioning a tissue engaging portion of an end effector of an ablation device near a 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 and second tissue contacting portions is in electrical contact with the target tissue; applying electrical ablation energy to the end effector to form a lesion in the target tissue such that a magnitude of at least one electrical parameter differs among the first tissue contact portion, the intermediate tissue contact portion, and the second tissue contact portion, the magnitude at the intermediate tissue contact portion being smaller than the magnitude at the first tissue contact portion and larger than the magnitude at the second tissue contact portion.

78. 78. The method of claim 77, wherein applying the electrical ablation energy to the end effector comprises applying the electrical ablation energy to a discrete first electrode comprising the first tissue contact portion and a discrete second electrode comprising the second tissue contact portion.

79. 80. The method of claim 78, wherein applying the electrical ablation energy to the end effector comprises applying the electrical ablation energy to a discrete intermediate electrode that comprises the intermediate tissue contact portion.

80. the intermediate electrodes include at least two sequentially arranged, discrete intermediate electrodes; 80. The method of claim 79, wherein applying the electrical ablation energy to the discrete intermediate electrodes comprises applying the electrical ablation energy to the at least two sequentially disposed, discrete intermediate electrodes, whereby the magnitude of the at least one electrical parameter differs incrementally between the at least two sequentially disposed, discrete intermediate electrodes.

81. 50. The method of claim 49, wherein applying electrical ablation energy to the end effector comprises applying the electrical ablation energy to a semiconductor element comprising the intermediate tissue contact portion.

82. 82. The method of claim 81, wherein applying electrical ablation energy to the end effector comprises applying the electrical ablation energy to the semiconductor element, the semiconductor element comprising the first tissue contacting portion and the second tissue contacting portion.

83. applying electrical ablation energy to the end effector includes applying the electrical ablation energy from an ablation energy source to a first electrical conductor and a second electrical conductor; the first electrical conductor is electrically coupled to the semiconductor element near the first tissue contact portion; 83. The method of claim 82, wherein the second electrical conductor is electrically coupled to the semiconductor element near the second tissue contact portion.

84. applying electrical ablation energy to the end effector includes applying the electrical ablation energy from the ablation energy source to an intermediate conductor; 82. The method of claim 81, wherein the intermediate conductor is electrically coupled to the semiconductor element near the intermediate tissue contact portion.

85. 85. The method of claim 84, wherein applying the electrical ablation energy from the ablation energy source to the intermediate conductor comprises applying the electrical ablation energy from the ablation source to the intermediate conductor such that a magnitude of the at least one electrical parameter differs between the first conductor, the intermediate conductor, and the second conductor, and a magnitude of the intermediate tissue contact is between a magnitude of the first tissue contact and a magnitude of the second tissue contact.

86. 86. The method of claim 85, wherein applying the electrical ablation energy from the ablation source to the intermediate conductor comprises applying the electrical ablation energy from the ablation source to the intermediate conductor from the first conductor through a first resistor and from the second conductor through a second resistor.

87. 82. The method of claim 81, wherein applying electrical ablation energy to the end effector comprises applying the electrical ablation energy to a discrete first electrode comprising the first tissue contact portion and a discrete second electrode comprising the second tissue contact portion.

88. 78. The method of claim 77, wherein the at least one electrical parameter comprises an electrical potential.

89. 78. The method of claim 77, wherein the at least one electrical parameter comprises current.

90. 78. The method of claim 77, wherein the electrical ablation energy comprises radiofrequency electrical energy.

91. 78. The method of claim 77, wherein the electrical ablation energy comprises pulsed field ablation electrical energy.

92. the ablation device comprises a shaft disposed proximally on the end effector; 78. The method of claim 77, wherein positioning the tissue engaging portion of the end effector of the ablation device near the target tissue comprises using the shaft to position the tissue engaging portion of the end effector of the ablation device.

93. the ablation device comprises a handle disposed proximally on the shaft; 93. The method of claim 92, wherein positioning the tissue engaging portion of the end effector of the ablation device near the target tissue comprises using the handle to position the tissue engaging portion of the end effector of the ablation device.

94. the ablation device comprising at least one connecting element configured to electrically couple the end effector to an external ablation energy source; 78. The method of claim 77, wherein applying the electrical ablation energy to the end effector comprises applying the electrical ablation energy to the end effector via the at least one connecting element.

95. 1. A method for ablating tissue, comprising: positioning an end effector of an ablation device such that a first contact portion, a second contact portion, and an intermediate contact portion disposed between the first contact portion and the second contact portion of the end effector are in physical contact with the tissue, the intermediate contact portion including at least one of an electrode and a semiconductor, the first contact portion being in electrical communication with a first electrode, and the second contact portion being in electrical communication with a second electrode; applying electrical energy to the first electrode and the second electrode such that a magnitude of at least one electrical parameter differs between the first contact and the second contact, the magnitude at the intermediate contact being smaller than the magnitude at the first contact and larger than the magnitude at the second contact.

96. 1. An ablation device for ablating tissue, comprising: An end effector, an end effector comprising: a first contact portion, a second contact portion, and an intermediate contact portion disposed between the first contact portion and the second contact portion, the intermediate contact portion comprising 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, the first electrode and the second electrode being spaced apart from each other by a first distance, the first electrode and the intermediate contact portion being spaced apart from each other by a second distance, and the second electrode and the intermediate contact portion being spaced apart from each other by a third distance, the first distance being greater than either the second distance or the third distance, and a surface area of ​​at least one of the first electrode and the second electrode being an integer multiple of a surface area of ​​any one of the plurality of intermediate electrodes; an ablation device for ablating tissue, wherein the first contact portion, the intermediate contact portion, and the second contact portion are electrically coupled when the end effector contacts the tissue, and when the first electrode and the second electrode are supplied with electrical ablation energy, the magnitude of at least one electrical parameter differs among the first contact portion, the intermediate contact portion, and the second contact portion, such that the magnitude at the intermediate contact portion is smaller than the magnitude at the first contact portion and larger than the magnitude at the second contact portion.

97. 97. Any method, process, apparatus, or system comprising one or more elements of any one of claims 1 to 96.

98. 98. Any combination of one or more elements according to any one of claims 1 to 97.

Images