Electrode assembly including an expandable isolation member

Abstract

An electrode assembly includes an electrode pair, the electrode pair including a first electrode and a second electrode, the first electrode and the second electrode being configured to be selectively energized to provide electroporation therapy. The electrode assembly also includes an expandable isolation member axially disposed between the first electrode and the second electrode. One of the first electrode and the second electrode is located proximal to the proximal end of the expandable isolation member, and the other of the first electrode and the second electrode is located distal to the distal end of the expandable isolation member. The expandable isolation member is configurable between a contracted configuration and an expanded configuration. The expandable isolation member includes a circumferential sealing surface configured to be sealingly engaged with patient tissue such that when engaged with the tissue, the expandable isolation member inhibits fluid communication and electrical communication between the first electrode and the second electrode.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 983,200 filed on February 28, 2020, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates generally to medical devices for use with the human body. In particular, the present disclosure relates to electroporation systems and electrode assemblies having expandable isolation members that can be used in such electroporation systems. Background Art

[0004] Various treatments are used to treat various conditions that afflict the human anatomy. For example, cardiac arrhythmias are sometimes treated with ablation therapy. When tissue is ablated, or at least subjected to ablative energy generated by an ablation generator and delivered by an ablation catheter, lesions are formed in the tissue. Electrodes mounted on or within the ablation catheter are used to produce tissue necrosis in cardiac tissue to correct conditions such as atrial arrhythmias (including but not limited to ectopic atrial tachycardia, atrial fibrillation, and atrial flutter). Arrhythmias (i.e., irregular heart rhythms) can produce various dangerous conditions, including loss of synchronized atrioventricular contraction and blood flow stagnation, which can lead to various diseases and even death. It is believed that the main cause of atrial arrhythmias is stray electrical signals in the left or right atrium of the heart. The ablation catheter applies ablative energy (e.g., radiofrequency energy, cryoablation, laser, chemicals, high-intensity focused ultrasound, etc.) in cardiac tissue, thereby producing lesions in cardiac tissue. This damage disrupts the undesired electrical pathways, thereby limiting or preventing stray electrical signals that can cause arrhythmias.

[0005] Electroporation is a candidate method for treating arrhythmias. Electroporation therapy includes pore formation induced by an electric field on the cell membrane. The electric field can be induced by applying a direct current (DC) signal transmitted as a relatively short duration pulse. Such pulses can be repeated to form a pulse sequence. When this electric field is applied to tissues in the body, cells in the tissue are subjected to the action of the transmembrane potential, thereby opening the holes in the cell wall, which is therefore called electroporation. Electroporation can be reversible (i.e., the temporarily opened holes will reseal) or irreversible (i.e., the holes will remain open). For example, in the field of gene therapy, reversible electroporation (i.e., temporarily opened holes) is used to transfect high molecular weight therapeutic vectors into cells. In other therapeutic applications, a properly configured pulse sequence can be used alone to cause cell destruction, for example, by causing irreversible electroporation (IRE). Summary of the invention

[0006] The present invention relates to an electroporation system, which includes a catheter shaft and an electrode assembly coupled to the catheter shaft. The electrode assembly includes an electrode pair, the electrode pair including a first electrode and a second electrode, the first electrode and the second electrode being configured to be selectively energized to provide electroporation therapy. The electrode assembly also includes an expandable isolation member axially arranged between the first electrode and the second electrode. One of the first electrode and the second electrode is located proximal to the proximal end of the expandable isolation member, and the other of the first electrode and the second electrode is located distal to the distal end of the expandable isolation member. The expandable isolation member can be configured between a contracted configuration and an expanded configuration. The expandable isolation member includes a circumferential sealing surface, which is configured to be sealingly engaged with patient tissue, so that when engaged with patient tissue, the expandable isolation member inhibits fluid communication and electrical communication between the first electrode and the second electrode. The electroporation system also includes an electroporation generator, which is coupled to the first electrode and the second electrode in communication, and is configured to provide an electroporation signal to the first electrode and the second electrode to provide electroporation therapy to the patient tissue.

[0007] The present disclosure also relates to an electrode assembly for a catheter system. The electrode assembly includes an electrode pair, the electrode pair including a first electrode and a second electrode, the first electrode and the second electrode being configured to be selectively energized to provide electroporation therapy. The electrode assembly also includes an expandable isolation member axially disposed between the first electrode and the cathode. One of the first electrode and the second electrode is located proximal to the proximal end of the expandable isolation member, and the other of the first electrode and the second electrode is located distal to the distal end of the expandable isolation member. The expandable isolation member is capable of being configured between a contracted configuration and an expanded configuration. The expandable isolation member includes a circumferential sealing surface configured to sealably engage with patient tissue so that when engaged with patient tissue, the expandable isolation member inhibits fluid communication and electrical communication between the first electrode and the second electrode.

[0008] The present disclosure also relates to a method, which includes advancing an electrode assembly to a target tissue site. The electrode assembly includes an electrode pair, the electrode pair including a first electrode and a second electrode. The electrode assembly also includes an expandable isolation member axially disposed between the first electrode and the second electrode. One of the first electrode and the second electrode is located proximal to the proximal end of the expandable isolation member, and the other of the first electrode and the second electrode is located distal to the distal end of the expandable isolation member. The expandable isolation member is configurable between a contracted configuration and an expanded configuration, and includes a circumferential sealing surface configured to be sealingly engaged with patient tissue, so that when engaged with the patient tissue, the expandable isolation member inhibits fluid communication and electrical communication between the first electrode and the second electrode. The method also includes transitioning the expandable isolation member from a contracted configuration to an expanded configuration, engaging the target tissue site with the expandable isolation member to inhibit fluid communication between the first electrode and the second electrode, and providing an electroporation signal to the first electrode and the second electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic block diagram of an electroporation therapy system.

[0010] Figure 2 Is applicable to Figure 1 Side view of a first exemplary electrode assembly of the system.

[0011] Figure 3 Is applicable to Figure 1 A perspective view of another exemplary electrode assembly of the system.

[0012] Figure 4 yes Figure 3 A cross-sectional view of an electrode assembly is shown.

[0013] Figure 5 Is applicable to Figure 1 A perspective view of another exemplary electrode assembly of the system.

[0014] Figure 6 Is applicable to Figure 1 A perspective view of another exemplary electrode assembly of the system.

[0015] Figure 7 is a flow chart of an exemplary method according to the present disclosure.

[0016] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.It should be understood that the drawings are not necessarily drawn to scale. DETAILED DESCRIPTION

[0017] The present disclosure generally relates to medical devices for use with the human body. Specifically, in many embodiments, the present disclosure relates to electroporation systems and electrode assemblies for use with such electroporation systems. The disclosed embodiments can provide more consistent and improved patient outcomes during electroporation treatment. For example, embodiments of the present disclosure utilize an electrode assembly that includes an expandable isolation member and a pair of electrodes disposed on opposite ends of the electrode assembly. The expandable isolation member is configured to isolate one electrode from another electrode at a target electroporation location (e.g., fluid and electrical isolation), thereby allowing the electric field and corresponding electroporation current to bypass the isolation member and pass through tissue at the target location. The electrode assembly of the present disclosure helps to improve the positioning of electroporation treatment, thereby reducing the voltage output required to induce electroporation in tissue at the target location. Additional embodiments of the present disclosure utilize different distal electrode assemblies to achieve various functions, including point ablation and cardiac tissue mapping.

[0018] Although exemplary embodiments of the present disclosure are described with respect to pulmonary vein isolation (PVI), it is contemplated that the features and methods of the present disclosure described herein may be incorporated into various systems and various applications as would be understood by one of ordinary skill in the art based on the disclosure herein.

[0019] Now referring to the accompanying drawings, Figure 1 An exemplary embodiment of a system 10 for electroporation therapy is shown. Typically, various embodiments include an electrode assembly disposed at the distal end of a catheter. As used herein, "proximal" refers to the direction toward the end of a catheter near a clinician, and "distal" refers to the direction away from the clinician and (usually) within the patient's body. The electrode assembly includes one or more separate electrically isolated electrode elements. In some embodiments, each electrode element (also referred to herein as a catheter electrode) is wired separately so that it can be selectively paired or combined with any other electrode element to act as a bipolar or multipolar electrode.

[0020] System 10 can be used for irreversible electroporation (IRE) to destroy tissue. Specifically, system 10 can be used for electroporation-induced primary necrosis treatment, which refers to the effect of delivering electric current in a manner that directly causes irreversible loss of plasma membrane (cell wall) integrity, thereby causing its rupture and cell necrosis. This cell death mechanism can be regarded as an "outside-in" process, that is, the destruction of the outer cell wall has a harmful effect on the inside of the cell. Typically, for plasma membrane electroporation, electric current is transmitted between closely spaced electrodes as a pulsed electric field in the form of a short direct current (DC) pulse, which can transmit an electric field strength sufficient to cause irreversible electroporation in target cells. In some specific embodiments, system 10 is configured to deliver an electroporation pulse signal with a relatively high voltage and a low pulse duration.

[0021] As further described herein, irreversible electroporation via a multi-electrode catheter can achieve pulmonary vein isolation with a single shock per vein, which allows for a much shorter procedure time than sequentially positioning a radiofrequency (RF) ablation catheter tip around the vein. It should be understood that the mechanism of cell destruction in electroporation is not primarily due to thermal effects, but rather to disruption of cell membranes by application of a high voltage electric field. Thus, electroporation can avoid some of the possible thermal effects that may occur when using RF energy. Thus, this "cold" or "non-thermal" treatment has desirable properties.

[0022] It should be understood that although the energization strategy may be described as involving DC pulses, embodiments may use variations of DC pulses. For example, exponentially decaying pulses, exponentially increasing pulses, and combinations thereof may be used. In other embodiments, an energization strategy involving alternating current (AC) pulses may be used for IRE treatment.

[0023] The system 10 includes a catheter electrode assembly 12 including at least one catheter electrode configured for use as described above and in more detail below. The electrode assembly 12 is incorporated as part of a medical device such as a catheter 14 for performing electroporation treatment on tissue 16 in a patient's body 17. In the illustrative embodiment, the tissue 16 includes a heart or cardiac tissue. However, it should be understood that embodiments may be used to perform electroporation treatment on various other body tissues.

[0024] Figure 1 Also shown are a plurality of return electrodes 18, 20, and 21, which schematically represent body connections that can be used by various subsystems included in the overall system 10, such as an electroporation generator 26, an electrophysiology (EP) monitor such as an ECG monitor 28, a visualization, navigation, and / or mapping system 30 for visualization, mapping, and navigation of internal body structures. In the illustrated embodiment, the return electrodes 18, 20, and 21 are patch electrodes. It should be understood that the illustration of a single patch electrode is only schematic (for clarity), and the subsystem to which these patch electrodes are connected can and will typically include more than one patch (body surface) electrode. In other embodiments, the return electrodes 18, 20, and 21 can be any other type of electrode suitable for use as a return electrode, including, for example, one or more catheter electrodes. The return electrode as a catheter electrode can be a part of the electrode assembly 12 or a part of a separate catheter (not shown). In some embodiments, for example, the system 10 includes a bipolar catheter electrode assembly 12, which includes at least one electrode pair including two electrodes, one of which is used as a return electrode.

[0025] The electroporation generator 26 is configured to energize the electrode elements of the electrode assembly 12 according to an electroporation energization strategy, which may be predetermined or may be user-selectable. For electroporation-induced primary necrosis treatment, the generator 26 may be configured to generate a current that is delivered as a pulsed electric field through the electrode assembly 12 in the form of a short-duration DC pulse transmitted between a pair of electrodes of the electrode assembly 12, and is capable of delivering an electric field strength of approximately 0.1 to 1.0 kV / cm (e.g., at a tissue site). The voltage amplitude required for irreversible electroporation is inversely proportional to the pulse duration. For example, when the pulse duration decreases, the voltage amplitude must be increased to achieve electroporation.

[0026] In some embodiments, the electroporation generator 26, sometimes also referred to herein as a DC energy source, is a biphasic electroporation generator 26 configured to generate a series of DC pulses having alternating polarities, i.e., continuous DC pulses that generate current in alternating directions. In other embodiments, the electroporation generator is a single-phase or multi-phase electroporation generator. In some embodiments, the electroporation generator 26 is configured to output energy of the DC pulses at selectable energy levels, such as 50 joules, 100 joules, 200 joules, etc. Other embodiments may have more or fewer energy settings, and the values ​​of the available settings may be the same or different. In some embodiments, electroporation generator 26 outputs or generates DC pulses having a peak value between about 500 volts and about 3.5 kilovolts, about 500 volts and about 2.5 kilovolts, about 600 volts and about 3.0 kilovolts, about 800 volts and about 3.5 kilovolts, about 600 volts and about 2.5 kilovolts, about 800 volts and about 2.5 kilovolts, about 1.0 kilovolts and about 3.5 kilovolts, about 600 volts and about 1.5 kilovolts, about 800 volts and about 2.0 kilovolts, or about 1.0 kilovolts and about 2.5 kilovolts. Other embodiments may output or generate any other suitable voltage.

[0027] In some embodiments, electroporation generator 26 outputs or generates DC pulses with pulse durations in the range of 1 nanosecond to 100 microseconds (μs), 1 nanosecond to 50 μs, 0.1 μs to 100 μs, 1 nanosecond to 20 μs, 0.1 μs to 50 μs, 1 μs to 100 μs, 1 nanosecond to 15 μs, 0.1 μs to 20 μs, 0.5 μs to 50 μs, 1 nanosecond to 10 μs, 0.1 μs to 15 μs, 1 nanosecond to 5 μs, 0.1 μs to 10 μs, 0.1 μs to 5 μs, less than 5 μs, less than 4 μs, less than 3 μs, and less than 2 μs. In other embodiments, the pulse signal generated by electroporation generator 26 may have a voltage amplitude of less than 500 volts or greater than 3.5 kilovolts, and may have a pulse duration greater than 100 μs or less than 1 nanosecond.

[0028] In one example, the electroporation generator 26 outputs or generates a biphasic pulse signal with a voltage amplitude in the range of 500 volts to 3.5 kilovolts, in the range of 500 volts to 2.5 kilovolts, in the range of 600 volts to 3.0 kilovolts, in the range of 600 volts to 2.5 kilovolts, or in the range of 800 volts to 2.5 kilovolts, and each phase of the biphasic pulse signal has a pulse duration in the range of 400 nanoseconds to 20 μs, or in the range of 500 nanoseconds to 1.5 μs. In addition, the phase of the biphasic pulse signal can be offset by a non-zero interval, for example, in the range of 350 nanoseconds to 1 ms, or in the range of 500 nanoseconds to 1.5 μs.

[0029] Additional description of electroporation generators 26 and DC pulse characteristics suitable for use with the electrode assemblies described herein are described in U.S. patent application Ser. No. 17 / 247,198, filed Dec. 3, 2020, the disclosure of which is incorporated herein by reference in its entirety. In yet other embodiments, the electroporation generator 26 is configured to generate pulses comprising an AC signal.

[0030] Variable impedance 27 allows the impedance of the system to change. In addition, variable impedance 27 can be used to change one or more characteristics of the electroporation generator 26 output, such as amplitude, duration, pulse shape, etc. Although shown as a separate component, variable impedance 27 can be incorporated into the catheter 14 or the generator 26. Variable impedance 27 includes one or more impedance elements, such as resistors, capacitors or inductors (not shown) connected in series, in parallel, or in series and / or in parallel. In the illustrated embodiment, variable impedance 27 is connected in series with catheter 14. Alternatively, the impedance element of variable impedance 27 can be connected in parallel with catheter 14, or connected in series and in parallel with catheter 14. In addition, in other embodiments, the impedance element of variable impedance 27 is connected in series and / or in parallel with return electrode 18. Some embodiments include more than one variable impedance 27, and each variable impedance 27 can include one or more impedance elements. In such an embodiment, each variable impedance 27 can be connected to a different catheter electrode or catheter electrode group to allow the impedance of each catheter electrode or catheter electrode group to change independently. In other embodiments, the impedance of system 10 may not need to be changed, and variable impedance 27 may be omitted.

[0031] The system 10 may also include a host computer system 32 (including an electronic control unit 50 and a data storage device or memory 52), which in some embodiments may be integrated with the system 30. The system 32 may also include conventional interface components, such as various user input / output mechanisms 34a and a display 34b, as well as other components.

[0032] In the illustrative embodiment, the catheter 14 includes a cable connector 40 or interface, a handle 42, and a shaft 44 having a proximal end 46 and a distal end 48. The catheter 14 may also include other conventional components not shown herein, such as a temperature sensor, additional electrodes, and corresponding conductors or wires. The connector 40 provides a mechanical and electrical connection for a cable 56 extending from the generator 26. The connector 40 may include conventional components known in the art and, as shown, is disposed at the proximal end of the catheter 14.

[0033] The handle 42 provides a position for the clinician to hold the catheter 14, and may further provide a device for steering or guiding the shaft 44 within the body 17. For example, the handle 42 may include a device for changing the length of the guidewire extending through the catheter 14 to the distal end 48 of the shaft 44 or a device for manipulating the axis 44. In addition, in some embodiments, the handle 42 can be configured to change the shape, size and / or orientation of a portion of the catheter and / or electrode assembly 12. The handle 42 is also conventional in the art, and it should be understood that the structure of the handle 42 can vary. In another exemplary embodiment, the catheter 14 can be driven or controlled by a robot. Therefore, instead of the clinician manipulating the handle to advance / retract and / or steer or guide the catheter 14 (particularly its shaft 44), the robot is used to manipulate the catheter 14.

[0034] The shaft 44 is an elongated tubular flexible member configured to move within the body 17. The shaft 44 is configured to support the electrode assembly 12 and accommodate associated conductors, and may contain additional electronic devices for signal processing or conditioning. The shaft 44 may also allow for the transport, delivery and / or removal of fluids (including flushing fluids, body fluids and expansion fluids), drugs and / or surgical tools or instruments. The shaft 44 may be made of conventional materials such as polyurethane and define one or more lumens that are configured to accommodate and / or transport electrical conductors, fluids or surgical tools. The shaft 44 may be introduced into a blood vessel or other structure within the body 17 via a conventional introducer. The shaft 44 may then be advanced, retracted and / or turned or guided through the body 17 to a desired location, such as the location of the tissue 16, including by using a guide wire or other means known in the art.

[0035] Figure 2 An exemplary electrode assembly 12 suitable for use with the system 10 is shown in the form of an expandable electrode assembly 100. The electrode assembly 100 generally extends axially along a longitudinal axis 106 from a proximal end 102 of the electrode assembly 100 to a distal end 104 of the electrode assembly 100. The proximal end 102 is coupled to the catheter shaft 44 (e.g., to the distal end of the shaft 44) via a verified coupler (not shown). In an exemplary embodiment, a guide wire 108 extends axially through the shaft 44 and through the electrode assembly 100. The guide wire 108 can be manipulated (e.g., using the handle 42) to adjust the position of the electrode assembly 100 within the body 17.

[0036] Electrode assembly 100 generally includes an expandable isolation member 110 and a pair of electrodes 112, 114. More specifically, expandable isolation member 110 extends between a proximal end 116 of expandable isolation member 110 and a distal end 118 of expandable isolation member 110. Electrodes 112, 114 are disposed adjacent proximal end 116 and distal end 118 of expandable isolation member 110, respectively, such that expandable isolation member 110 is axially disposed between electrodes 112, 114. Proximal electrode 112 is located adjacent proximal end 116 of expandable isolation member 110 and adjacent proximal end 102 of electrode assembly 100. Similarly, distal electrode 114 is located adjacent distal end 118 of expandable isolation member 110 and adjacent distal end 104 of electrode assembly 100. In an exemplary embodiment, distal end 118 of expandable isolation member 110 is adjacent distal end 104 of electrode assembly 100.

[0037] The electrodes 112, 114 can be used for various diagnostic and therapeutic purposes, including, for example, but not limited to, cardiac mapping and / or ablation (e.g., IRE ablation). For example, the electrode assembly 100 can be configured as a bipolar electrode assembly for bipolar-based electroporation therapy. Specifically, as described above, the electrodes 112, 114 are respectively electrically coupled to the generator 26 (e.g., via a suitable wire or other suitable electrical conductor extending through the catheter shaft 44) and are configured to be selectively energized with opposite polarities (e.g., by the electroporation generator 26 and / or the computer system 32) to generate an electric potential and a corresponding electric field therebetween for IRE therapy. That is, one of the electrodes 112, 114 is configured to serve as a cathode, and the other is configured to serve as an anode. For example, in a first embodiment, the electrode 112 is an anode and the electrode 114 is a cathode. In a second embodiment, the electrode 112 is a cathode and the electrode 114 is an anode. The electrodes 112, 114 can be any suitable electroporation electrodes. In an exemplary embodiment, the electrodes 112, 114 are ring electrodes. The electrodes 112, 114 may have any other shape or configuration. It is recognized that the shape, size and / or configuration of the electrodes 112, 114 may affect various parameters of the electroporation therapy applied. For example, increasing the surface area of ​​one or both electrodes 112, 114 may reduce the applied voltage required to produce the same level of tissue destruction. In addition, although each of the proximal electrode 112 and the distal electrode 114 is shown as a single electrode, either or both of the proximal electrode 112 and the distal electrode 114 may alternatively be implemented as two or more discrete electrodes. In addition, although the electrode assembly 100 is described as a bipolar electrode assembly, it should be understood that in some embodiments, the electrode assembly 100 may be configured as a monopolar electrode assembly and use a patch electrode (e.g., return electrode 18) as a return or indifferent electrode.

[0038] In an exemplary embodiment, expandable isolation member 110 can be in a collapsed configuration (not shown) and an expanded configuration (e.g. Figure 2 114). For example, the expandable isolation member 110 is delivered to a target location (e.g., axially disposed within the catheter shaft 44) of the tissue 16 within the body 17 in a contracted configuration and is transformed into an expanded configuration at the target location. The expandable isolation member 110 is configured to sealably engage with the tissue 16 at the target location and inhibit electrical communication between the electrodes 112, 114 (e.g., by at least partially insulating the distal electrode 114 from the proximal electrode 112). More specifically, as further described herein, the expandable isolation member 110 is formed of an electrically insulating material. Therefore, the current 122 between the proximal electrode 112 and the distal electrode 114 is diverted around the expandable isolation member 110. Figure 2 Multiple currents 122 of different shapes and sizes of diversions are depicted about expandable isolation member 110. In some embodiments, the shape and size of expandable isolation member 110 can be selected to affect current 122 thereabout (e.g., magnitude of diversion, shape or direction of current 122 produced, etc.).

[0039] In addition, the expandable isolation member 110 is configured to sealingly engage the tissue 16 when in the expanded configuration. In an exemplary embodiment, the expandable isolation member 110 includes a circumferential sealing surface 120 that is configured for sealing engagement with the tissue 16, such that when engaged with the patient tissue, the expandable isolation member 110 inhibits fluid communication between the electrodes 112, 114, and thus inhibits electrical communication (e.g., electrical current). For example, when the expandable isolation member 110 is used for PVI or to isolate other cylindrical or tubular tissue (e.g., other vasculature tissue), the expandable isolation member 110 can occlude the pulmonary vein and inhibit or substantially prevent blood flow therearound. Therefore, when the electrodes 112, 114 are energized, the current 122 flows between the electrodes 112, 114 through the tissue 16 adjacent to the expandable isolation member 110, rather than through the blood. In this way, electroporation treatment can be more localized, and therefore, the voltage required to be applied to cause the desired amount of cell destruction is reduced. Specifically, fluids (e.g., blood) are more conductive than tissue, so current flows more easily through blood than tissue, and electroporation therapy is less effective. By blocking blood flow as described herein, the current 122 between electrodes 112, 114 is diverted to pass through adjacent tissue 16, thereby increasing the effectiveness of electroporation therapy at a given voltage.

[0040] In an exemplary embodiment, expandable isolation member 110 includes an outer layer 124 formed or constructed of an electrically insulating material. For example, outer layer 124 may include polyethylene terephthalate (PET). Outer layer 124 may include any other suitable electrically insulating material and may be capable of accommodating expansion and contraction of electrode assembly 100. In certain embodiments, as shown in FIG. Figure 2 As shown, the expandable isolation member 110 is specifically implemented as an expandable balloon. In such an embodiment, the expandable balloon is coupled to a fluid source 126 for selectively expanding the balloon (e.g., when the electrode assembly 100 has been advanced to a target location within the body 17 and has been deployed from the catheter shaft 44). In some embodiments, the fluid source includes a dielectric fluid, such as deionized water, saline, carbon dioxide gas, nitrous oxide gas, and / or air. In other embodiments, the expandable isolation member 110 can be selectively expanded using other means, such as an expandable frame (e.g., a frame formed of a shape memory material) retained within the outer layer 124.

[0041] although Figure 2 10 has an elongated spherical shape, but expandable isolation member 110 can have any other shape or configuration that can achieve a seal and thereby inhibit fluid and / or electrical communication between electrodes 112, 114. A particular shape and / or configuration can be selected for a particular tissue isolation desired.

[0042] For example, in other embodiments, it may be desirable to isolate and disrupt tissue within solid or planar tissue, such as the ventricular wall (as opposed to the relatively cylindrical isolation of a blood vessel). In such embodiments, the distal end 118 of the expandable isolation member 110 may be inverted and concave, and the distal electrode 114 may be located within the concave portion of the distal end 118. The distal end 118 may engage or press against tissue to seal or isolate the distal electrode 114 from the proximal electrode 112, such that the current 122 between the electrodes 112, 114 is diverted to pass through the tissue engaged with the distal end 118 (e.g., the ventricular wall).

[0043] It is contemplated that a complete seal may not occur between the expandable isolation member 110 and the adjacent tissue 16. For example, the circumferential sealing surface 120 may not be fully engaged with the tissue 16, and there may be some fluid (blood) flowing through the circumferential sealing surface 120. In some embodiments, complete engagement or sealing is not necessary for successful electroporation therapy. The level of seal can be determined by a variety of methods. In some embodiments, fluoroscopic contrast material is introduced into the blood flow upstream of the expandable isolation member 110, and the presence or amount of contrast material downstream of the expandable isolation member 110 is determined using x-rays. In other embodiments, Doppler ultrasound is used to determine the level of fluid flow through the expandable isolation member 110. In other embodiments, the impedance between the electrodes 112, 114 is measured before and after the electrode assembly 100 is placed at the target location; a threshold change in impedance reflects adequate sealing. In other embodiments, the electrode assembly 100 includes a pressure transducer (not shown) located on the distal end 104, which is used to measure fluid pressure to reflect the level of seal between the expandable isolation member 110 and the tissue 16. Additional and / or alternative methods may be used to determine the seal level. Furthermore, any of the above methods may be used repeatedly. Specifically, an initial level of seal may be determined, and in response, the position of the electrode assembly 100 may be adjusted. Subsequent seal levels may be determined, and so on, until a sufficient or adequate seal level is reached (e.g., based on a threshold and / or a physician's determination).

[0044] Furthermore, based on the seal level determined using any of the above methods (or any other suitable method), a suitable voltage level to be applied may be selected.A reduction in the seal level may require an increase in the applied voltage.

[0045] Figure 3 and Figure 4 1 and 2 are perspective and cross-sectional views, respectively, of another exemplary electrode assembly 12 suitable for use with the system 10, shown in the form of an expandable electrode assembly 200. The electrode assembly 200 is similar in many respects to the electrode assembly 100, and similar elements in the electrode assembly 200 are labeled with corresponding reference numerals within 200. Specifically, the electrode assembly 200 generally extends axially along a longitudinal axis 206 from a proximal end 202 of the electrode assembly 200 to a distal end 204 of the electrode assembly 200. The proximal end 202 is coupled to the catheter shaft 44 (e.g., to the distal end of the shaft 44) via a suitable coupler (not shown). In the exemplary embodiment, a guide wire 208 (see Figure 4 ) extends axially through the shaft 44 and the electrode assembly 200. The guide wire 208 can be manipulated (e.g., using the handle 42) to adjust the position of the electrode assembly 200 within the body 17.

[0046] Electrode assembly 200 includes an expandable isolation member 210 and electrodes 212 and 214. Additionally, in an exemplary embodiment, electrode assembly 200 includes a distal tip electrode 230. Electrodes 212 and 214 are disposed adjacent a proximal end 216 and a distal end 218 of expandable isolation member 210, respectively, such that expandable isolation member 210 is axially disposed between electrodes 212, 214. Specifically, proximal electrode 212 is adjacent a proximal end 216 of expandable isolation member 210 and is proximal to proximal end 102 of electrode assembly 200. Likewise, distal electrode 214 is adjacent a distal end 218 of expandable isolation member 210 and is proximal to distal end 204 of electrode assembly 200. In an exemplary embodiment, distal end 218 of expandable isolation member 210 is proximal to distal end 204 of electrode assembly 200.

[0047] The distal tip electrode 230 is located distal to the distal electrode 214. The distal tip electrode 230 is physically separated and electrically isolated from the distal electrode 230 by an electrically insulating member 232 (eg, an annular interface element formed of an electrically insulating material).

[0048] The electrodes 212, 214 may be used for a variety of diagnostic and therapeutic purposes, including, for example, but not limited to, cardiac mapping and / or ablation (e.g., IRE ablation). For example, the electrode assembly 200 may be configured as a bipolar electrode assembly for bipolar-based electroporation therapy, as described above with respect to the electrode assembly 100. Specifically, as described above, the electrodes 212, 214 are configured to be selectively energized with opposite polarities (e.g., by the electroporation generator 26 and / or the computer system 32) to generate an electric potential and a corresponding electric field therebetween for IRE therapy. That is, one of the electrodes 212, 214 is configured to function as a cathode, while the other is configured to function as an anode.

[0049] The distal tip electrode 230 may also be used for various diagnostic and therapeutic purposes, including, for example, but not limited to, cardiac mapping and / or point ablation (e.g., point IRE ablation). Specifically, the distal tip electrode 230 is electrically coupled to the generator 26 separately (e.g., via a wire 234 extending through the catheter shaft 44). Thus, each of the electrodes 212, 214, and 230 is electrically coupled to the generator 26 via a separate electrical conductor (e.g., wire). The distal tip electrode 230 is configured to be selectively energized independently of the electrodes 212, 214 (e.g., via the electroporation generator 26 and / or the computer system 32). In some embodiments, the distal tip electrode 230 is energized with a polarity opposite to that of one of the electrodes 212 or 214 to generate an electrical potential and a corresponding electric field therebetween for IRE therapy. Specifically, when the distal tip electrode 230 is energized with a polarity opposite to the distal electrode 214, the electric field generated therebetween can be suitable for point IRE treatment to precisely target tissue near the distal end 204 of the electrode assembly 200. In an exemplary embodiment, the distal tip electrode 230 is embodied as a ring electrode. The distal tip electrode 230 can be any suitable electroporation electrode and can have any other shape or configuration.

[0050] In addition, although the electrode assembly 200 is described as a bipolar electrode assembly, it should be understood that in some embodiments, the electrode assembly 200 can be configured as a monopolar electrode assembly and use a patch electrode (e.g., return electrode 18) as a return or indifferent electrode. For example, in a monopolar treatment application, the current path can be directed from the distal tip electrode 230 to the return electrode 18.

[0051] In an exemplary embodiment, expandable isolation member 210 can be in a collapsed configuration (not shown) and an expanded configuration (e.g. Figure 3 and Figure 4 For example, the expandable isolation member 210 is delivered to a target location of the tissue 16 within the body 17 (e.g., axially disposed within the catheter shaft 44) in a collapsed configuration and is transformed into an expanded configuration at the target location. As described in more detail above, the expandable isolation member 210 is configured to sealably engage with the tissue 16 at the target location and inhibit electrical communication between the electrodes 212 and 214 and / or between the electrodes 230 and 212 (e.g., by at least partially insulating the distal electrode 214 and / or the distal tip electrode 230 from the proximal electrode 212).

[0052] In an exemplary embodiment, expandable isolation member 210 includes an outer layer 224 formed or constructed of an electrically insulating material. For example, outer layer 224 may include polyethylene terephthalate (PET) or any other suitable electrically insulating material capable of accommodating the expansion and contraction of electrode assembly 200. Figure 3 and Figure 4As shown, the expandable isolation member 210 is specifically implemented as an expandable balloon. In such an embodiment, the expandable balloon is coupled to a fluid source 226 for selectively expanding the balloon (e.g., when the electrode assembly 200 has been advanced to a target location within the body 17 and has been deployed from the catheter shaft 44). In some embodiments, the fluid source includes a dielectric fluid, such as deionized water, saline, carbon dioxide gas, nitrous oxide gas, and / or air. The expandable balloon is selectively expanded by directing the dielectric fluid from the fluid source 226 through the fluid cavity 240 and into the inner cavity 244 of the expandable balloon through the fluid port 242. In other embodiments, the expandable isolation member 210 can be selectively expanded using other means, such as an expandable frame (e.g., a frame formed of a shape memory material) retained within the outer layer 224.

[0053] Figure 5 A perspective view of another exemplary electrode assembly 12 suitable for use with the system 10 is shown, shown in the form of an expandable electrode assembly 300. The electrode assembly 300 is similar in many respects to the electrode assemblies 100 and 200, and similar elements in the electrode assembly 300 are labeled with corresponding reference numerals within 300. Specifically, the electrode assembly 300 generally extends axially along a longitudinal axis 306 from a proximal end 302 of the electrode assembly 300 to a distal end 304 of the electrode assembly 300. The proximal end 302 is coupled to the catheter shaft 44 (e.g., to the distal end of the shaft 44) via a suitable coupler (not shown).

[0054] Electrode assembly 300 includes an expandable isolation member 310 extending between a proximal end 316 of the expandable isolation member 310 and a distal end 318 of the expandable isolation member 310. Electrode assembly 300 also includes a plurality of electrodes, including a proximal electrode 312, a first distal electrode 350, a second distal electrode 352, and a distal tip electrode 330. Proximal electrode 312 is disposed near proximal end 316 of expandable isolation member 310. First distal electrode 350 is disposed adjacent to distal end 318 of expandable isolation member 310. Second distal electrode 352 is located distal to first distal electrode 350. Second distal electrode 352 is physically separated and electrically isolated from first distal electrode 350 by an electrically insulating member 354. In an exemplary embodiment, the distance between first and second distal electrodes 350, 352 (e.g., the width or depth of insulating member 354) is known, such that first and second distal electrodes 350, 352 are suitable for mapping cardiac tissue. In one embodiment, the distance between the first and second distal electrodes 350, 352 (eg, the width or depth of the insulating member 354) is approximately 0.5 mm.

[0055] The distal tip electrode 330 is located distal to the second distal electrode 352. The distal tip electrode 330 is physically separated and electrically isolated from the second distal electrode 352 by an electrically insulating member 332 (eg, an annular interface element formed of an electrically insulating material).

[0056] Electrodes 312, 350, 352, and 330 may be used for a variety of diagnostic and therapeutic purposes, including, for example, but not limited to, cardiac mapping and / or ablation (e.g., IRE ablation). For example, electrode assembly 300 may be configured as a bipolar electrode assembly for bipolar-based electroporation therapy, as described above with respect to electrode assembly 100.

[0057] Each electrode 312, 350, 352, and 330 is electrically coupled to the generator 26 (e.g., via a respective wire or other suitable electrical conductor extending through the catheter shaft 44). Each electrode 312, 350, 352, and 330 is configured to be selectively energized independently of one another (e.g., by the electroporation generator 26 and / or the computer system 32).

[0058] In some embodiments, multiple pairs or groups of electrodes are energized with opposite polarities to generate an electric potential and a corresponding electric field therebetween for IRE treatment. For example, the distal tip electrode 330 can be selectively energized as one of a point cathode or a point anode, and the second distal electrode 352 or the first distal electrode 350 can be selectively energized with opposite polarity as the other of the point cathode or the point anode for point IRE treatment or point ablation. In another example, the distal electrode 330 can be selectively energized as one of the cathode or the anode, and the proximal electrode 312 can be selectively energized with opposite polarity as the other of the cathode or the anode for IRE treatment of tissue surrounding the expandable isolation member 310, as described above with respect to the electrode assembly 100. Similarly, either or both of the second distal electrode 352 and the first distal electrode 350 can be selectively energized as one of the cathode or anode, and the proximal electrode 312 can be selectively energized with opposite polarity as the other of the cathode or anode for IRE treatment of tissue surrounding the expandable isolation member 310, as described above with respect to the electrode assembly 100.

[0059] In other embodiments, the electrode assembly 300 can be configured as a monopolar electrode assembly and use a patch electrode (e.g., return electrode 18) as a return or indifferent electrode. For example, in a monopolar treatment application, the current path can be directed from the distal tip electrode 330 to the return electrode 18.

[0060] In addition, the electrode assembly 300 is suitable for cardiac mapping. For example, bipolar measurements of electrophysiological (EP) data can be performed between the distal tip electrode 330 and the first distal electrode 350, and / or between the second distal electrode 352 and the first distal electrode 350. Additionally or alternatively, any one of the electrodes 330, 350, 352 can be used for monopolar mapping (e.g., relative to the patch electrodes 18, 20 and / or 21).

[0061] Figure 6 A perspective view of another exemplary electrode assembly 12 suitable for use with system 10 is shown, shown in the form of an expandable electrode assembly 400. Electrode assembly 400 is similar in many respects to electrode assemblies 100, 200, and 300, and similar elements in electrode assembly 400 are labeled with corresponding reference numerals within 400. Specifically, electrode assembly 400 is substantially similar to electrode assembly 300, except that electrode assembly 400 does not include a distal tip electrode.

[0062] Electrode assembly 400 generally extends axially from proximal end 402 to distal end 404 along longitudinal axis 406. Electrode assembly 400 includes an expandable isolation member 410 extending between a proximal end 416 of expandable isolation member 410 and a distal end 418 of expandable isolation member 410. Electrode assembly 400 also includes a plurality of electrodes, including a proximal electrode 412, a first distal electrode 450, and a second distal electrode 452. Proximal electrode 412 is disposed proximal to proximal end 416 of expandable isolation member 410. First distal electrode 450 is disposed adjacent to distal end 418 of expandable isolation member 410. Second distal electrode 452 is located distal to first distal electrode 450. Second distal electrode 452 is physically separated and electrically isolated from first distal electrode 450 by an electrically insulating member 454. In an exemplary embodiment, the distance between the first and second distal electrodes 450, 452 (e.g., the width or depth of the insulating member 454) is known, so that the first and second distal electrodes 450, 452 are suitable for mapping cardiac tissue. In one embodiment, the distance between the first and second distal electrodes 450, 452 (e.g., the width or depth of the insulating member 454) is approximately 0.5 mm.

[0063] The electrodes 412, 450, and 452 can be used for various diagnostic and therapeutic purposes, including, for example, but not limited to, cardiac mapping and / or ablation (e.g., IRE ablation). For example, the electrode assembly 400 can be configured as a bipolar electrode assembly for bipolar-based electroporation therapy, as described above with respect to the electrode assembly 100. Each electrode 412, 450, and 452 is electrically coupled to the generator 26 (e.g., via a corresponding wire or other suitable electrical conductor extending through the catheter shaft 44). Each electrode 412, 450, and 452 is configured to be selectively energized independently of each other (e.g., by the electroporation generator 26 and / or the computer system 32). In some embodiments, multiple pairs or groups of electrodes are energized with opposite polarities to generate an electric potential and a corresponding electric field therebetween for IRE therapy. For example, either or both of the second distal electrode 452 and the first distal electrode 450 can be selectively energized as one of the cathode or anode, and the proximal electrode 412 can be selectively energized with opposite polarity as the other of the cathode or anode for IRE treatment of tissue surrounding the expandable isolation member 410, as described above with respect to the electrode assembly 100. In addition, the electrode assembly 400 is suitable for cardiac mapping. For example, bipolar measurement of electrophysiological (EP) data can be performed between the second distal electrode 452 and the first distal electrode 450. Additionally or alternatively, the first and / or second distal electrodes 450, 452 can be used for unipolar mapping (e.g., relative to the patch electrodes 18, 20 and / or 21).

[0064] Figure 7 is to use an electrode assembly (e.g., electrode assembly 12, 100, 200, 300 and / or 400, respectively, as Figure 1 , Figure 2 , Figure 3 , Figure 5 and Figure 6 Flowchart of method 500 for performing a medical procedure (e.g., electroporation therapy) at a target location (as shown). Method 500 includes advancing 502 an electrode assembly to a target location (e.g., a target tissue site). As described herein, the electrode assembly includes an electrode pair including an anode (e.g., a first electrode) and a cathode (e.g., a second electrode) and an expandable isolation member axially disposed between the anode and the cathode. One of the anode and the cathode is located proximal to the proximal end of the expandable isolation member, and the other of the anode and the cathode is located distal to the distal end of the expandable isolation member. The expandable isolation member is capable of being configured between a contracted configuration and an expanded configuration. The expandable isolation member includes a circumferential sealing surface configured to be sealingly engaged with patient tissue such that when engaged with patient tissue, the expandable isolation member inhibits fluid communication and electrical communication between the anode and the cathode.

[0065] Method 500 also includes transitioning 504 the expandable isolation member from the collapsed configuration to the expanded configuration and engaging 506 the target tissue site with the expandable isolation member to inhibit fluid communication between the anode and the cathode. Method 500 also includes providing 508 an electroporation signal to the anode and the cathode.

[0066] It should be readily understood that in other embodiments of the present disclosure, method 500 may include additional, fewer and / or alternative steps. Although certain steps of the example method are numbered, such numbering does not indicate that these steps must be performed in the order listed. Therefore, specific steps do not need to be performed in the exact order in which they are presented, unless such an order is specifically required for the description thereof. These steps may be performed in the order listed or in other suitable orders.

[0067] Although the embodiments and examples disclosed herein have been described with reference to specific embodiments, it should be understood that these embodiments and examples are merely illustrations of the principles and applications of the present disclosure. Therefore, it should be understood that various modifications may be made to the illustrative embodiments and examples, and other arrangements may be designed without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the present application is intended to cover modifications and variations of these embodiments and their equivalents.

[0068] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the disclosure, including making and using any device or system and performing any combined method. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have the same structural elements as the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

Claims

1. An electroporation system, comprising: Catheter shaft; an electrode assembly coupled to the catheter shaft, the electrode assembly comprising: an electrode pair comprising a first electrode and a second electrode configured to be selectively energized to provide electroporation therapy; and an expandable isolation member axially disposed between the first electrode and the second electrode, wherein one of the first electrode and the second electrode is located proximal to the proximal end of the expandable isolation member and the other of the first electrode and the second electrode is located distal to the distal end of the expandable isolation member, the expandable isolation member being configurable between a collapsed configuration and an expanded configuration; wherein the expandable isolation member includes a circumferential sealing surface configured to sealingly engage patient tissue such that when engaged with the patient tissue, the expandable isolation member inhibits fluid communication and electrical communication between the first electrode and the second electrode; and an electroporation generator coupled in communication with the first electrode and the second electrode and configured to provide an electroporation signal to the first electrode and the second electrode to provide the electroporation therapy to the patient tissue, wherein one of the first electrode and the second electrode located distal to the distal end of the expandable isolation member comprises a pair of ring electrodes separated by an insulating member, wherein the pair of ring electrodes are configured to map the patient tissue, Wherein, the electroporation system is configured as follows: determining a level of seal between the circumferential sealing surface and the patient tissue; and The voltage of the electroporation signal is increased based on the decreased sealing level.

2. The electroporation system of claim 1, wherein the electroporation generator is one of a monophasic electroporation generator, a biphasic electroporation generator, and a multiphasic electroporation generator.

3. The electroporation system of claim 1, wherein the electroporation therapy is irreversible electroporation therapy (IRE).

4. The electroporation system of claim 1, wherein the expandable isolation member comprises an expandable balloon.

5. The electroporation system of claim 4, wherein the inflatable balloon is coupled to a fluid source for selectively inflating the balloon.

6. The electroporation system of claim 5, wherein the fluid source comprises a dielectric fluid.

7. The electroporation system of claim 6, wherein the fluid source comprises a fluid selected from the group consisting of deionized water, saline, carbon dioxide gas, nitrous oxide gas, and air.

8. The electroporation system of claim 1, wherein the expandable isolation member comprises an outer layer comprised of an electrically insulating material.

9. The electroporation system of claim 1, wherein the first electrode is an anode and the second electrode is a cathode.

10. An electrode assembly for a catheter system configured to provide electroporation therapy, the electrode assembly comprising: an electrode pair including a first electrode and a second electrode configured to be selectively energized to perform electroporation therapy; as well as an expandable isolation member axially disposed between the first electrode and the second electrode, wherein one of the first electrode and the second electrode is located proximal to the proximal end of the expandable isolation member and the other of the first electrode and the second electrode is located distal to the distal end of the expandable isolation member, the expandable isolation member being configurable between a collapsed configuration and an expanded configuration; wherein the expandable isolation member includes a circumferential sealing surface configured for sealing engagement with patient tissue such that when engaged with the patient tissue, the expandable isolation member inhibits fluid communication and electrical communication between the first electrode and the second electrode, wherein one of the first electrode and the second electrode located distal to the distal end of the expandable isolation member comprises a pair of ring electrodes separated by an insulating member, wherein the pair of ring electrodes are configured to map the patient tissue, Wherein the electrode pair is configured to be selectively energized to apply a first amount of voltage and to apply an increased second amount of voltage based on a determined decrease in a seal level between the circumferential sealing surface and the patient tissue.

11. The electrode assembly of claim 10, wherein the expandable isolation member comprises an expandable balloon.

12. The electrode assembly of claim 11, wherein the expandable balloon is coupled to a fluid source for selectively expanding the balloon.

13. The electrode assembly of claim 12, wherein the fluid source comprises a dielectric fluid.

14. The electrode assembly of claim 12, wherein the fluid source comprises a fluid selected from the group consisting of deionized water, saline, carbon dioxide gas, nitrous oxide gas, and air.

15. The electrode assembly of claim 10, wherein the expandable isolation member comprises an outer layer of an electrically insulating material.

16. The electrode assembly of claim 15, wherein the outer layer comprises polyethylene terephthalate.

17. The electrode assembly of claim 10, further comprising a distal tip electrode located distal to one of the first electrode and the second electrode, the one electrode being located distal to the distal end of the expandable isolation member.

18. The electrode assembly of claim 17, wherein the distal tip electrode and one of the first electrode and the second electrode are configured to be selectively energized for electroporation therapy.

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