Devices and methods for delivering electroporation therapy

Abstract

The electroporation device includes a shaft and an adaptable electrode assembly. The shaft has a proximal end and a distal end, and the adaptable electrode assembly is located at the distal end of the shaft. The electrode assembly has a first surface and a second surface, and the first surface includes a first non-conductive portion and a first electrode disposed in the center of the first surface. The first non-conductive portion is defined by a first surface area, and the first electrode is defined by a second surface area, and the first surface area is greater than the second surface area.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 63 / 040,751, entitled “DEVICE AND METHOD FOR DELIVERING ELECTROPORATION THERAPY,” filed June 18, 2020, which is incorporated herein by reference.

[0002] The present invention relates generally to medical devices, and more particularly to medical devices for delivering electroporation therapy.

[0003] Electroporation therapy involves applying an electric field to a cell membrane to increase the permeability of the cell membrane. In some applications, electroporation is utilized to permanently damage or destroy a target cell, which is called irreversible electroporation (IRE) therapy. One advantage of IRE therapy is that it is possible to damage or ablate a target cell without affecting adjacent cells. IRE therapy is applicable to any procedure in which it is desirable to ablate tissue, including, for example, cancer therapy, and / or cardiac ablation therapy to alleviate / stop certain arrhythmia conditions, including ectopic atrial tachycardia, atrial fibrillation, and atrial flutter.

[0004] In particular, IRE treatment serves as an alternative to conventional cardiac ablation techniques. The primary cause of atrial arrhythmias is suspected to be stray electrical signals within the left or right atrium of the heart. Conventional cardiac ablation treatments require the delivery of ablative energy (e.g., radio frequency (rf) energy, laser, etc.) to cardiac tissue. The ablative energy, i.e., thermal energy, damages cardiac tissue and destroys undesirable electrical pathways that cause arrhythmic conditions.

[0005] IRE therapy allows for targeted ablation of cardiac tissue to create desired lesions, thus disrupting undesirable electrical pathways, without the introduction of thermal energy associated with conventional ablation treatments. Summary of the Invention

[0006] According to one embodiment, an electroporation device includes a shaft having a proximal end and a distal end and a conformable electrode assembly disposed at the distal end of the shaft, the electrode assembly including a first side and a second side, the first side including a first non-conductive portion and a first electrode disposed centrally on the first side, the first non-conductive portion defined by a first surface area, the first electrode defined by a second surface area, the first surface area being greater than the second surface area.

[0007] According to another aspect, a method of delivering electroporation therapy includes introducing a catheter shaft having an adaptable electrode assembly to a target location within a patient. The method may further include placing a first side of the adaptable electrode assembly in contact with the target tissue, the first side of the adaptable electrode assembly may include a first non-conductive portion and a first electrode centrally disposed on the first side, the first non-conductive portion surrounding the first electrode. The method may further include delivering an electroporation pulse to the first electrode.

[0008] According to another aspect, an electroporation treatment system may include a catheter and an electroporation generator. The catheter may further include a handle, an adaptable electrode assembly, and a shaft coupled to the handle at a proximal end and to the electrode assembly at a distal end. The adaptable electrode assembly may include a first surface and a second surface opposite the first surface, the first surface including a first non-conductive portion and a first electrode attached to the first non-conductive portion, the first electrode being centrally disposed, and the non-conductive portion surrounding the first electrode in a plane defined by the first surface. The electroporation generator may be coupled to the catheter to deliver electroporation pulses to the first electrode. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram of a medical system for providing electroporation therapy, according to some embodiments. [Figure 2a] FIG. 1 is an isometric view of a catheter and compatible electrode assembly for delivering electroporation therapy, according to some embodiments. [Figure 2b] FIG. 1 is an isometric view of a catheter and compatible electrode assembly positioned adjacent to selected tissue for delivering electroporation therapy, according to some embodiments. [Figure 3a] FIG. 2 illustrates an isometric view of a non-conductive material and first and second electrodes separated by the non-conductive material, according to some embodiments. [Figure 3b] FIG. 2 is a side view of a non-conductive material separating a first electrode and a second electrode according to some embodiments. [Figure 3c] FIG. 2 illustrates a top view of a first surface of a non-conductive material and a first electrode according to some embodiments. [Figure 3d] 4 is a cross-sectional view of a non-conductive material and a first electrode and a second electrode according to some embodiments. [Figure 4a]1A-1C are top views of non-conductive portions of a conformable electrode assembly according to some embodiments. [Figure 4b] 1A-1C are top views of non-conductive portions of a conformable electrode assembly according to some embodiments. [Figure 4c] 1A-1C are top views of non-conductive portions of a conformable electrode assembly according to some embodiments. [Diagram 5] FIG. 1 is an isometric view of a catheter and a compatible electrode assembly including a central electrode and multiple peripheral electrodes for delivering electroporation therapy, according to some embodiments. [Figure 6a] FIG. 1 is an isometric view of an adaptable electrode assembly according to some embodiments. [Figure 6b] 1A-1D are cross-sectional views of a conformable electrode assembly according to some embodiments. [Figure 6c] FIG. 1 illustrates an isometric view of a circuit board having a central electrode and multiple peripheral electrodes disposed thereon, according to some embodiments. [Figure 7a] FIG. 1 is a side view of a catheter and a compatible electrode assembly, according to some embodiments. [Figure 7b] FIG. 1 is a top view of a catheter and a compatible electrode assembly, according to some embodiments. [Figure 8] FIG. 1 is a flow diagram illustrating a method of delivering irreversible electroporation therapy (IRE), according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The disclosed invention is directed to a medical device including a catheter and a conformable electrode assembly. The first side of the conformable electrode assembly includes a first electrode centrally disposed in a conformable non-conductive portion. The surface area of ​​the non-conductive portion is greater than the surface area of ​​the first electrode, such that the non-conductive portion extends around the first electrode. In some embodiments, the non-conductive portion and the first electrode are located substantially on the same plane, and the non-conductive portion surrounds the first electrode in a defined plane. The presence of the non-conductive portion surrounding the first electrode ensures that the conductive path formed between the first electrode and the second electrode during electroporation treatment includes tissue adjacent to the first side of the conformable electrode assembly.

[0011] FIG. 1 is a schematic block diagram of a system 100 for providing electroporation therapy, according to some embodiments. The system 100 includes a catheter 102, an electroporation generator 104, a computer system 106, an input / output 108, and a display 110. The catheter 102 includes a handle 112 and a shaft 114 having a distal end 116 and a proximal end 118. A conformable electrode assembly 120 is disposed at the distal end 116 of the shaft 114 and configured to deliver electroporation therapy to adjacent tissue 122. In the embodiment shown in FIG. 1, the conformable electrode assembly 120 is disposed to deliver electroporation therapy to cardiac tissue within the heart, although in other embodiments, the distal end 116 of the catheter 102, including the electrode assembly 120, may be disposed elsewhere within the body to deliver a desired electroporation therapy. The handle 112 is utilized to guide the distal end 116 of the shaft 114 to a desired location within the body. In some embodiments, the distal end 116 of the shaft includes one or more sensors (e.g., magnetic, optical, electrical, etc.) that are utilized to visualize the distal end 116 and / or navigate the distal end 116 to a desired location within the body.

[0012] The electroporation pulses delivered by the electrode assembly 120 are generated by the electroporation generator 104. In some embodiments, the magnitude, duration, and number of delivered pulses may be altered by the electroporation generator 104. The electroporation generator 104 is coupled to the interface connector 124 of the catheter 102 via a cable 126. The electroporation pulses delivered to the handle 102 are transmitted to the electrode assembly 120 via the shaft 114. Additionally, in some embodiments, the catheter 102 includes one or more sensors (e.g., magnetic, electrical, optical, etc.) disposed along the shaft 114 to provide sensor input to the computer system 106. In some embodiments, the same electrodes utilized to generate the electroporation pulses are also utilized to collect electrical signals (e.g., electrocardiogram signals, impedance signals, etc.) and thus provided to the computer system 106 via the electroporation generator 104. In other embodiments, the sensed signal, whether electrical, magnetic, or optical, may be provided directly to the computer system 106 (i.e., the cable 126 may be coupled directly to the computer system 106 rather than via the electroporation generator 104).

[0013] In some embodiments, computer system 106 includes a storage device 128 capable of storing computer-readable instructions and an electronic control unit (ECU 130) capable of executing computer-readable instructions. In some embodiments, computer system 106 communicates bidirectionally with input / output 108 and further displays information via display 110. In some embodiments, computer system 106 controls the generation and delivery of electroporation pulses by electroporation generator 104. This may include varying one or more of the amplitude (i.e., strength), duration, and number of pulses delivered by electroporation generator 104.

[0014] Additionally, the computer system 106 may utilize one or more sensing signals, whether electrical, magnetic, or optical, as inputs to enable one or more functions including visualization, navigation, and / or mapping. For example, the one or more sensing signals may be utilized to visualize the position of the catheter within the patient's body, as well as to facilitate navigation of the catheter through the patient's vasculature to a desired location within the patient's body. In some embodiments, electrical signals (e.g., electrocardiogram signals) sensed by electrodes disposed on the electrode assembly 120 may be utilized to map the propagation of electrical signals within the patient's heart, or to confirm that a problematic signal has been blocked following delivery of an electroporation pulse. In some embodiments, a surface electrode 134 is utilized to receive electrical signals and / or provide electrical signals to the body to be received by one or more electrodes disposed on the electrode assembly 120. For example, electrical signals generated at the surface electrode 134 (or two or more surface electrodes) may be detected by one or more electrodes disposed at the distal end 116 of the catheter 102 within the patient's body. In other embodiments, the surface electrode 134 may function as a return path for an electrical signal delivered to the electrode assembly 120, such as as a return path for an electroporation pulse delivered by the electroporation generator 104 to the electrode assembly 120.

[0015] In some embodiments, one or more sensing signals are utilized to verify the position of the electrode assembly 120 relative to the tissue targeted for electroporation. In particular, in some embodiments, one or more sensing signals are utilized to verify that a first surface of a conformable electrode assembly, which includes at least a first electrode and a non-conductive material surrounding the first electrode, is in contact with the tissue. Physical contact between the first surface of the inconformable electrode assembly and the tissue selected to receive electroporation therapy ensures that the conductive path formed between the first electrode and the second electrode includes the tissue adjacent to the first electrode.

[0016] 2a and 2b, one embodiment of the adaptable electrode assembly 220 is shown in more detail. In some embodiments, the adaptable electrode assembly 220 is located at the distal end 216 of the shaft 214 and includes a first surface 244 and a second surface 252 opposite the first surface 244. In some embodiments, the first surface 244 includes a non-conductive portion 248 having a first surface area and a first electrode 246 centrally disposed relative to the non-conductive portion 248 and having a second surface area smaller than the first surface area. That is, the non-conductive portion 248 surrounds the first electrode or extends from the first electrode to an edge of the adaptable electrode assembly 220 in a plane defined by the first surface 244. The top surface of the first electrode 246 (i.e., the top surface of the first electrode that is brought into contact with the tissue to be treated) is exposed. Additionally, in some embodiments, the electrode assembly 220 includes one or more ring electrodes 240, 242 disposed on the shaft 214. In some embodiments, a second electrode may also be disposed on a second side 252 of the conformable electrode assembly 220 (shown in FIG. 2b). In other embodiments, the second side 252 of the conformable electrode assembly 220 does not include a second electrode.

[0017] As shown in FIG. 2a, the first electrode 246 is centrally located on the first face 244 of the adaptable electrode assembly 220. In some embodiments, the first electrode 246 and the non-conductive portion 248 together provide a relatively flat surface. In some embodiments, the non-conductive portion 248 includes a recess for receiving the first electrode 246, and the first electrode 246 is surrounded by the non-conductive portion 248 on all sides except the surface that is contacted with tissue. In some embodiments, the first electrode 246 is mounted within the recess of the non-conductive portion 248, and the top surface of the first electrode 246 and the top surface of the non-conductive portion 248 are relatively flat. In some embodiments, the first electrode 246 is recessed within the non-conductive portion 248, and the non-conductive portion 248 is raised or protruding relative to the first electrode 246. In some embodiments, the first electrode 246 is mounted on the non-conductive portion 248 such that the first electrode 246 protrudes from the non-conductive portion 248.

[0018] In some embodiments, the non-conductive portion 248 surrounds the first electrode 246 to ensure that the conductive path formed between the first electrode 246 and the second electrode (wherever located) includes the tissue adjacent to the first electrode 246. That is, contact between the non-conductive material 248 surrounding the first electrode 246 and the adjacent tissue ensures that the conductive path formed between the first electrode 246 and the second electrode includes the tissue adjacent to the first electrode 246. In the absence of the non-conductive portion 248 surrounding the first electrode 246 and / or in the absence of contact with the tissue surrounding the first electrode 246, a conductive path may be formed through the blood pool adjacent to the first electrode 246, bypassing the tissue adjacent to the first electrode 246. This may result in a smaller electric field being applied to the selected tissue, thereby reducing the effectiveness of the electroporation treatment. Thus, the tissue-contacting non-conductive portion 248 is desirably sized larger than the surface of the first electrode 246 to ensure that the tissue-contacting non-conductive portion 248 surrounding the first electrode 246 includes tissue adjacent the electrode assembly 220 that is compatible with the conductive path formed between the first electrode 246 and the second electrode. To this end, in some embodiments, the non-conductive portion 248 is constructed from a flexible material such as silicone, and the shape of the non-conductive portion 248 can be changed to conform to the geometry of the tissue being treated. In other embodiments, many other suitable materials may be used for the non-conductive portion 248, including, for example, Pebax, nylon, and rubber. In other embodiments, the non-conductive portion 248 may be constructed from a more rigid material. In some embodiments, the first surface 244, including at least the non-conductive portion 248, is relatively flat in the absence of external forces (i.e., the first surface is not pressed against tissue). In other embodiments, the first surface 244, including at least the non-conductive portion 248, has a geometric shape other than planar in the absence of an external force. For example, the first surface 244 may have a concave or convex shape.In some embodiments, utilizing a non-planar geometry for the first surface 244 may utilize a flexible non-conductive material 248 to ensure contact between the non-conductive material 248 and the corresponding tissue, i.e., the non-conductive material 248 is able to flex and conform to the tissue, thereby ensuring contact between the non-conductive material 248 and the tissue in the area surrounding the first electrode 246.

[0019] 2b, in some embodiments, the electrode assembly 220 is connected to the shaft 214 via a hinge 258, which allows the orientation of a major plane defined by the electrode assembly 220 to be changed or deflected relative to the shaft 214. In some embodiments, the deflection of the electrode assembly 220 is controlled by an operator via the handle 112 (shown in FIG. 1). In other embodiments, the deflection of the electrode assembly 220 is responsive to a force applied to the electrode assembly 220 when it is brought into contact with adjacent tissue. In this manner, the hinge 218 assists the first surface 244 in contacting the tissue 250 to be treated.

[0020] During electroporation treatment, the first surface 244 is placed in contact with a tissue 250 (e.g., cardiac tissue) selected to receive electroporation treatment. An electroporation pulse or series of pulses is delivered between the first electrode 246 and the second electrode, with one electrode functioning as an anode and the other as a cathode. A conductive path is formed between the first electrode 206 and the second electrode. For example, in the embodiment shown in FIG. 2b, the second electrode may be realized by an electrode 254 disposed on the second surface 252 of the conformable electrode assembly 220. The non-conductive portion 248 surrounds the first electrode 246, thereby ensuring that the conductive path includes the tissue 250 adjacent to the first electrode 246. That is, the non-conductive portion 248 prevents a conductive path from being formed between the first electrode 246 and the second electrode 254 that does not include the tissue 250 adjacent to the first electrode 246. In the embodiment shown in FIG. 2b, the second side 252 of the adaptable electrode assembly 220 is approximately symmetrical to the first side 244 (shown in FIG. 2a). This is beneficial in some embodiments because either the first side 244 or the second side 252 need only be in contact with the tissue to be treated. In some embodiments, a determination is made as to which electrode should be utilized as the anode and which electrode should be utilized as the cathode according to whether the first electrode 246 or the second electrode 254 is in contact with the tissue 250. However, in other embodiments, whether the electrode in contact with the tissue 250 is the anode or the cathode does not affect the effectiveness of the electroporation treatment.

[0021] In some embodiments, the second surface 252 may not be symmetrical with respect to the first surface 244. For example, in some embodiments, only the first surface 244 is in contact with the tissue 250 to be treated at any one time. In this case, the second electrode 254 does not need to be surrounded by the non-conductive material 256. As a result, the location and size of the second electrode 254 can be varied as desired. For example, the second electrode 254 may be disposed at another location along the second surface 252 or may include the entire surface area of ​​the second surface 252. In still other embodiments, the second electrode may not be disposed on the second surface 252. For example, in some embodiments, the role of the second electrode as either a cathode or an anode relative to the first electrode 246 is provided by the ring electrode 240 or 242. In still other embodiments, the role of the second electrode is provided by the surface electrode 134 shown in FIG. 1. In other embodiments, the second electrode may be disposed on a separate catheter or medical device. As described in more detail below, in some embodiments, one or both of the first electrode 246 and the second electrode 254 may be utilized to perform other functions besides the delivery of electroporation pulses. For example, these other functions may include one or more of mapping, navigation, and / or visualization of the medical device.

[0022] 3a-3d, an adaptable electrode assembly 320 is shown, according to some embodiments. In particular, FIG. 3a is an isometric view of the adaptable electrode assembly 320, FIG. 3b is a side view of the adaptable electrode assembly 320, FIG. 3c is a top view of the adaptable electrode assembly 320, and FIG. 3d is a cross-sectional view along line dd of FIG. 3b. In some embodiments, the adaptable electrode assembly 320 includes a first non-conductive portion 360, a second non-conductive portion 362, a middle non-conductive portion 364, a first electrode 346, and a second electrode 354. In this embodiment, the first electrode 346 is mounted within a recess in the first non-conductive portion 360, forming a substantially flat surface, as shown in FIG. 3b and FIG. 3d. Similarly, the second electrode 354 is mounted within a recess in the second non-conductive portion 362, forming a substantially flat surface. As mentioned above, in other embodiments, the first electrode 346 and / or the second electrode 354 may be more recessed and the first non-conductive portion 360 and / or the second non-conductive portion 362 may be raised relative to the corresponding electrode. In particular, in some embodiments, the first non-conductive portion 360 and / or the second non-conductive portion 362 may be flexible and / or compressible, in which case it may be desirable for the first electrode 346 and the second electrode 354 to be recessed from the top of the corresponding non-conductive portion 360 and non-conductive portion 362.

[0023] In some embodiments, the first electrode 346 and / or the second electrode 354 may protrude from the top surface of the corresponding non-conductive portion 360 and non-conductive portion 362. In some embodiments, the presence of the intermediate non-conductive portion 364 separates the first non-conductive portion 360 from the second non-conductive portion 362. In some embodiments, the intermediate non-conductive portion 364 provides electrical insulation between the first electrode 346 and the second electrode 354. In the embodiment shown in Figures 3a-3d, the first non-conductive portion 360 and the second non-conductive portion 362 have a cylindrical shape and a diameter larger than the diameter of the intermediate non-conductive portion 364. In some embodiments, the difference in diameter forms a space 366 defined by the distance w between the first non-conductive portion 360 and the second non-conductive portion 362, as shown in Figure 3d. In some embodiments, the space 366 formed between the first non-conductive portion 360 and the second non-conductive portion 362 is configured to receive features for attaching the adaptable electrode assembly 320 to the shaft of a catheter.

[0024] In some embodiments, the first non-conductive portion 360 and the second non-conductive portion 362 are flexible. In some embodiments, the middle non-conductive portion 364 is made of the same material as the first non-conductive portion 360 and the second non-conductive portion 362. However, in other embodiments, the middle non-conductive portion 364 is made of a different non-conductive material that is more or less flexible than the first non-conductive portion 360 and the second non-conductive portion 362. For example, in some embodiments, the first non-conductive portion 360 and the second non-conductive portion 362 may be composed of one or more of silicone, Pebax, nylon, and / or rubber, and the middle non-conductive portion 364 is composed of a polyimide circuit material. In some embodiments, the first non-conductive portion 360 and the second non-conductive portion 362 may be adapted to fit (i.e., rolled up) into the tube of the shaft. Upon removal from the shaft, first conductive portion 360 and second conductive portion 362 return to the desired shape, such as, for example, a planar shape as shown in Figures 3a-3d. In other embodiments, the desired shape (i.e., in the absence of an external force) may be other shapes, such as a concave shape, a convex shape, etc.

[0025] As shown in FIG. 3c, the first non-conductive portion 360 surrounds the first electrode 346, and the surface area of ​​the first non-conductive portion 360 (including the recess that holds the first electrode 346) is greater than the surface area of ​​the first electrode 346. In the embodiment shown in FIGS. 3a-3d, both sides of the electrode assembly are symmetrical, so the same is true for the second non-conductive portion 362 and the electrode 354. As mentioned above, in some embodiments, the second side 352 is not placed against tissue to provide therapy, in which case the geometry of the second electrode 354 and the second non-conductive portion 362 may be altered (e.g., the position of the second electrode 354 on the second side 352 may be altered, the size of the second electrode 354 may be expanded to the full surface area of ​​the second side 354, etc.).

[0026] The cross-sectional view shown in FIG. 3d illustrates the presence of a non-conductive material between the first electrode 346 and the second electrode 354. Specifically, the cross-sectional view illustrates that the first electrode 346 and the second electrode 354 are surrounded on each side by a non-conductive material (except for the electrode portions exposed along the first side 344 and the second side 352). As shown in FIG. 3d, the conductive path formed between the first electrode 346 and the second electrode 354 must pass around the first non-conductive portion 360 and the second non-conductive portion 362. This ensures that the conductive path includes tissue adjacent to either the first side 344 or the second side 352.

[0027] 4a-4c, a top view of a plurality of non-conductive portions 470, 474, and 478 is shown. The non-conductive portions 470, 474, and 478 each include a recess 472, 476, and 480 for receiving and holding an electrode. In each of these embodiments, the recesses 472, 476, and 480 are the same size. By varying the size of the non-conductive portions, the size of the area receiving electroporation treatment can be varied accordingly. Reducing the size of the non-conductive portions reduces the size of the area receiving electroporation treatment. Increasing the size of the non-conductive portions increases the size of the area receiving electroporation treatment. Depending on the application, various configurations of electrode assemblies with non-conductive portions of various sizes may be selected to increase or decrease the area receiving electroporation treatment. For example, in cardiac ablation type treatments that rely on irreversible electroporation (IRE) treatments, it may be beneficial to utilize an electrode assembly with larger non-conductive portions (e.g., as shown in FIG. 4c) to reduce the time required to ablate the desired tissue. In other embodiments, more targeted cell selection may be required and a non-conductive portion with a smaller diameter (eg, as shown in FIG. 4a) may be utilized.

[0028] In some embodiments, the diameter of recess 472 configured to receive an electrode is 50% or less than the diameter of non-conductive portion 470, as shown in Figure 4a. In some embodiments, the diameter of recess 476 is 33% or less than the diameter of non-conductive portion 474, as shown in Figure 4b. In some embodiments, the diameter of recess 480 is 25% or less than the diameter of non-conductive portion 478, as shown in Figure 4c.

[0029] For example, in some embodiments, the diameter of the non-conductive portion 470 shown in Figure 4a is about 6-10 mm, and the diameter of the recess 472 is about 3-5 mm. Similarly, the diameter of the non-conductive portion 474 shown in Figure 4b is about 10-12 mm, and the diameter of the recess remains about 3-5 mm. Similarly, the diameter of the non-conductive portion 478 shown in Figure 4c is about 12-14 mm, and the diameter of the recess remains about 305 mm.

[0030] Referring to FIG. 5, another embodiment of an adaptable electrode assembly 520 is shown, according to some embodiments. In the embodiment shown in FIG. 5, the adaptable electrode assembly 520 is again disposed at the distal end 516 of the shaft 514 and includes a first surface 544 and a second surface 552 opposite the first surface 544. In some embodiments, the first surface 544 includes a non-conductive portion 548, a first central electrode 546, and a number of additional electrodes 584 disposed on an outer edge of the first surface 544. In some embodiments, the first central electrode 546 and the number of additional electrodes 584 are fabricated on a flexible circuit board 582 (shown in more detail in FIG. 6). Additionally, in some embodiments, the adaptable electrode assembly 520 may again include one or more ring electrodes 540, 542 disposed on the shaft 514. As mentioned above, in some embodiments, signals measured by the ring electrodes 540, 542 may be utilized for localization / navigation purposes. In some embodiments, one of the ring electrodes 540, 542 may be utilized as a return electrode for electroporation pulses delivered to the first central electrode 546. In some embodiments, a second central electrode (not shown) may also be disposed on the second face 552 of the electrode assembly 520. In some embodiments, the second face 552 may also include a number of additional electrodes disposed on the outer edge of the second face 552. In some embodiments, the second face 552 is symmetrical to the first face 544. In other embodiments, the second face 552 may have fewer or more electrodes than the first face 544, or may include no electrodes at all.

[0031] As shown in FIG. 5, the first central electrode 546 is surrounded by a non-conductive portion 548. In some embodiments, the non-conductive portion 548 includes a recess to accommodate the first central electrode 546, and the first central electrode 546 is surrounded by the non-conductive material 548 on all sides except the surface that is placed against the tissue. Again, the surface area of ​​the first central electrode 546 is less than the surface area of ​​the non-conductive portion 548. In some embodiments, the first central electrode 546 and the non-conductive portion 548 are relatively planar along the first surface 544. In some embodiments, the first central electrode 546 is recessed within the non-conductive portion 548, and the non-conductive portion 548 is raised relative to the first central electrode 546. As mentioned above, the purpose of non-conductive portion 548 surrounding first central electrode 546 is to ensure that the conductive path formed between first central electrode 546 and a second electrode (e.g., disposed on second surface 552) during an electroporation treatment includes tissue adjacent to first central electrode 546. That is, non-conductive portion 548 causes the conductive path to include adjacent tissue, as desired.

[0032] In some embodiments, the non-conductive portion 548 is also recessed to receive and hold the flexible circuit board 582, the plurality of electrodes 584, and the first central electrode 546. In some embodiments, the non-conductive portion 508 is recessed such that the plurality of electrodes 584 and the first central electrode 546 are relatively planar with the non-conductive portion 548. In other embodiments, the plurality of electrodes 584 may be recessed such that the non-conductive portion 584 is raised or protruding relative to the plurality of electrodes 584 (as described above with respect to the first central electrode 546). In some embodiments, it may be desirable for the plurality of electrodes 584 to protrude from the non-conductive portion 548 since the plurality of electrodes 584 are not utilized to deliver electroporation pulses, but are utilized for purposes such as mapping, navigation, and / or visualization. An advantage of the plurality of electrodes 584 protruding from the non-conductive portion 548 is that it helps ensure good physical contact with adjacent tissue to sense signals utilized for one or more of mapping, navigation, and / or visualization.

[0033] The multiple additional electrodes 584 are utilized to provide one or more additional functions associated with the electrode assembly 520. For example, the multiple additional electrodes 584 may be utilized to perform a mapping function, where the first surface 544 is placed against tissue and electrical signals within the tissue are detected by each of the multiple electrodes 584. The detected electrical signals may be utilized to detect and map electrical activity within the cardiac tissue, such as abnormal or erroneous electrical signals resulting in an arrhythmic condition. Additionally, the multiple additional electrodes 584 may be utilized for visualization and / or navigation of the distal end 516 of the shaft 514 within the patient's body. In some embodiments, the first central electrode 546 may be utilized in combination with the multiple electrodes 584 to aid in performing one or more of the mapping, visualization, and / or navigation functions.

[0034] As mentioned above, during electroporation treatment, it is desirable to place the first surface 544 (or the second surface 552, if the second surface includes an electroporation electrode) in contact with the tissue to be treated, thereby ensuring that the conductive path between the first central electrode 546 and the second electrode includes the tissue adjacent to the first central electrode 546. In some embodiments, a plurality of additional electrodes 584 may be utilized to detect that the first surface 544 is in contact with the desired tissue. In some embodiments, contact with the tissue is detected based on an electrical signal sensed by one or more of the plurality of additional electrodes 584. For example, sufficient contact of the non-conductive portion 548 surrounding the first central electrode 546 may be determined based on an electrical signal sensed by the electrode 584 in contact with the adjacent tissue (i.e., an electrical signal traveling through the cardiac tissue). If the electrode 584 is unable to detect an electrical signal, this indicates that the non-conductive portion 548 may not be in contact with the underlying tissue. In other embodiments, one or more other sensing signals may be utilized. For example, impedance between one or more of the plurality of electrodes 584 and the first central electrode 546 (and / or each other) may be utilized to determine whether the first surface 544 is in contact with the desired tissue. In some embodiments, the determination of whether the non-conductive portion 548 is in sufficient contact with the underlying tissue is based on a threshold number of the plurality of electrodes 584 sensing a signal indicative of physical contact with the underlying tissue. For example, in an embodiment in which the plurality of electrodes 584 includes a total of eight electrodes, the threshold may require six of the electrodes 584 to sense a signal indicative of contact with tissue to prove that the non-conductive portion 548 is in contact with the underlying tissue.

[0035] In some embodiments, the circuit board 582 is a flexible circuit that allows the circuit board 582 to flex with the flexible non-conductive portion 548. In some embodiments, the circuit board 582 includes a shape memory material. In some embodiments, the conformable electrode assembly 520 is constructed from a flexible material that allows the conformable electrode assembly 520 to be rolled up to fit into the tube of the shaft 514 during catheter navigation to a desired location within the patient. In some embodiments, when the conformable electrode assembly 520 is removed from the shaft 514, the shape memory material used in the circuit board 582 acts to return the conformable electrode assembly 520 to a desired shape. For example, in the embodiment shown in FIG. 5, both the first side 544 and the second side 552 extend approximately parallel to each other, and the geometry of the conformable electrode assembly 520 is relatively flat. In other embodiments, the shape memory material allows other shapes to be achieved by the electrode assembly 520. For example, the first side 544 may have a concave shape, a convex shape, or other desired geometry.

[0036] 6a-6c, there is shown an electrode assembly 620 utilizing a circuit board 682 in combination with a non-conductive portion 648. Figure 6a is an isometric view of the electrode assembly 620, Figure 6b is a cross-sectional view of the electrode assembly 620, and Figure 6c is an isometric view of the flexible circuit board 682.

[0037] As shown in FIG. 6c, the circuit board 682 includes a plurality of electrodes 684 disposed on the periphery of the circuit board 682 in addition to the first central electrode 646. In some embodiments, the circuit board 682 may be attached to a non-conductive portion of the electrode assembly (e.g., non-conductive portion 548 shown in FIG. 5). In other embodiments shown in FIGS. 6a-6b, the non-conductive portion 648 circumscribes (i.e., surrounds) at least a portion of the circuit board 682 and includes a plurality of recesses or openings that expose one or more electrodes associated with the circuit board 682. In the embodiment shown in FIG. 6a, the non-conductive portion 648 includes a central recess 645 that exposes the first central electrode 646 and a plurality of peripheral recesses 685, each of which exposes one of the plurality of peripheral electrodes 684. In some embodiments, the first central electrode 646 and the plurality of peripheral electrodes 684 are recessed relative to the plane of the non-conductive portion 648. In other embodiments, one or both of the first central electrode 646 and the plurality of peripheral electrodes 684, together with the non-conductive portion 648, form a substantially flat surface for contacting tissue. In some embodiments, the components and geometry provided on the first side 644 of the electrode assembly 620 are closely similar on the second side 652 of the electrode assembly 620. In other embodiments, the second side 652 may not include electrodes (and thus may have no recesses in the non-conductive portion 648) or may include only a subset of the electrodes and recesses included on the first side 644.

[0038] The cross-sectional view shown in FIG. 6b shows layers that are not visible in the view shown in FIG. 6a. For example, in the embodiment shown in FIG. 6b, an intermediate layer 692 is disposed adjacent to the circuit board 682. In some embodiments, the intermediate layer 692 is located between the first circuit board 682 (including the electrodes 646 and 684 associated with the first surface 644) and the second circuit board 694 associated with the electrodes (not numbered) disposed on the second surface 652. In some embodiments, the intermediate layer 692 includes a shape memory material, such as Nitinol (i.e., nickel titanium). In some embodiments, the shape memory material of the intermediate layer 692 allows the intermediate layer to be deformed (e.g., rolled up to fit the tube of the catheter) and then return to the generally planar shape shown in FIGS. 6a-6b. The flexible circuit boards 682, 694 in combination with the flexible non-conductive portion 648 may allow the electrode assembly 620 to be deformed to fit the tube of the catheter while navigating the electrode assembly 620 to a location at a desired site. Upon deployment of the electrode assembly 620 from the tube, the shape memory material (whether included as part of the intermediate layer 692 or elsewhere) can return to an original or predefined shape, such as the planar shape shown in FIGS. 6a-6b. In some embodiments, in conjunction with or instead of the intermediate layer 692 being comprised of a shape memory material, the circuit boards 682 and / or 694 are comprised of a shape memory material, and the first circuit board 682 and / or the second circuit board 694 are comprised of a shape memory material. In the example shown in FIGS. 6a-6c, the predefined configuration or shape of the electrode assembly is relatively flat. However, in other embodiments, the shape or configuration may include multiple possible geometric shapes, including, for example, a concave shape or a composite shape.

[0039] FIG. 6c shows the circuit board 682 separated from the non-conductive portion 648. In some embodiments, the circuit board 682 includes a proximal portion 690 that extends into the tube of the shaft, the proximal portion 690 including a plurality of contact pads 686 for providing contact to a plurality of electrodes 684 disposed on the periphery of the circuit board 682, and a contact pad 687 for providing contact to the first central electrode 646. The circuit board 682 further includes a distal portion 689 and a ring portion 688 that extend from the proximal portion 690. In particular, the ring portion 688 forms a ring around the distal portion 689. In some embodiments, the distal portion 689 extends across the diameter of the ring portion 688. The first central electrode 646 is mounted or fabricated on the distal portion 689. The plurality of electrodes 684 are equidistantly spaced along the ring portion 688. Each of the electrodes 684 is connected to one of the plurality of contact pads 686 via a conductive trace. Similarly, the first central electrode 646 is connected to a contact pad 687 via a conductive trace.

[0040] In some embodiments, the circuit board 682 may be a multi-layer structure (not shown in FIG. 6c). For example, in some embodiments, the circuit board 682 includes a top surface and a bottom surface, with at least some of the conductive traces formed between the contact pads 686 and the electrodes 684 disposed on the top surface and some of the conductive traces formed on the bottom surface. For example, in the embodiment shown in FIG. 6a, a subset of the conductive traces are shown extending along the top surface of the circuit board 682.

[0041] 7a and 7b, side and top views, respectively, of a shaft 714 and an electrode assembly 720 are shown, according to some embodiments. In FIG. 7a, the electrode assembly 720 is oriented such that the first side 744 and the second side 752 of the electrode assembly are not visible. In FIG. 7b, a top view of the shaft 714 and the electrode assembly 720 is shown, revealing the first central electrode 746 and an additional electrode 784 disposed on the outer edge of the electrode assembly 720.

[0042] 8 is a flow diagram of steps utilized to provide electroporation therapy, according to some embodiments. In step 800, a catheter shaft including an adaptable electrode assembly is introduced into a patient's body and moved to a target location. In some embodiments, one or more sensors including one or more electrodes disposed on the adaptable electrode assembly may be utilized to help navigate and / or visualize the position of the catheter within the patient's body.

[0043] In step 802, one or more physiological signals are measured using one or more electrodes disposed on a first surface of a conformable electrode assembly. In some embodiments, the conformable electrode assembly includes a plurality of electrodes disposed on an outer edge of the first surface, and each of the plurality of electrodes may be utilized to sense one or more electrical signals. For example, the sensed signal may include an electrical signal sensed in the myocardial tissue. In other embodiments, the sensed signal may include an impedance signal measured between two or more electrodes. In other embodiments, one or more signals or a combination of signals may be measured. In some embodiments, a first central electrode utilized to deliver the electroporation therapy may also be utilized to measure one or more physiological signals.

[0044] In step 804, contact with tissue is detected based on one or more signals measured in step 802. Before applying electroporation therapy (including irreversible electroporation (IRE)), it is desirable to ensure that the first surface (including the first electroporation electrode) is in contact with the tissue to be treated. In some embodiments, it is desirable that the non-conductive portion surrounding the first electroporation electrode is also in good contact with the tissue to ensure that a conductive path is formed between the electroporation electrodes that includes the tissue adjacent to the first electroporation electrode. In some embodiments, the determination is made based only on the signal measured by the first central electrode. In other embodiments, the determination is made based on a signal detected using one or more of a plurality of electrodes (if present) located on the outer edge of the first surface (e.g., as shown in Figures 5 and 6). In some embodiments, sufficient contact with tissue is detected when a threshold number of electrodes detect a signal indicative of tissue contact. For example, in some embodiments, sufficient contact with tissue is detected when six of eight electrodes located on the outer edge of the first surface detect contact with adjacent tissue. In other embodiments, other thresholds based on available sensors may be used to determine whether the first surface is in contact with adjacent tissue.

[0045] If no contact with tissue is detected in step 804, the electrode assembly is repositioned in step 806 and the process is repeated by measuring one or more physiological signals using one or more of the multiple electrodes in step 802. If contact with tissue is detected in step 804, electroporation therapy is initiated in step 808. In some embodiments, the electroporation therapy may include an irreversible electroporation therapy (IRE). In some embodiments, the electroporation therapy includes a series of pulses delivered between a pair of electrodes, i.e., a cathode and an anode, one of the electrodes being disposed on a first surface of the electrode assembly adjacent to the tissue.

[0046] In some embodiments, one or more physiological signals are measured at step 810 by one or more of the plurality of electrodes disposed on the first surface (which in some embodiments includes the electroporation electrode and / or one or more of the plurality of electrodes disposed on the outer edge of the first surface). In some embodiments, the measurements of the physiological signals are utilized to determine the effectiveness of the electroporation treatment delivered to the tissue. For example, in some embodiments, this may include monitoring electrical signals in the tissue to determine whether the electroporation was successful in blocking the propagation of these signals through the tissue that has undergone the electroporation treatment.

[0047] In step 812, a determination is made as to whether the electroporation treatment was successful based on the one or more physiological signals measured in step 810. If the one or more physiological signals indicate that the electroporation treatment was successful, the process ends (or the catheter is moved to a new location and the process is repeated again). If the one or more physiological signals indicate that the electroporation treatment was not successful (e.g., electrical signals are detected propagating through the tissue that has been electroporated), the process is repeated from step 802 with measurements of the one or more physiological signals to detect whether the first surface of the electrode assembly is in good contact with the tissue to be treated.

[0048] Although the invention has been described with reference to exemplary embodiments, those skilled in the art will recognize that various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is not intended that the invention be limited to the particular embodiments disclosed, but the invention is intended to include all embodiments falling within the scope of the appended claims.

[0049] DISCUSSION OF THE DISCLOSED EMBODIMENTS The following is a non-exclusive description of possible embodiments of the present invention.

[0050] According to one embodiment, an electroporation device includes a shaft having a proximal end and a distal end and a conformable electrode assembly located at the distal end of the shaft. The electrode assembly includes a first side and a second side, the first side including a first non-conductive portion and a first electrode located at a center of the first side, the first non-conductive portion defined by a first surface area, the first electrode defined by a second surface area, the first surface area being greater than the second surface area.

[0051] The device of the preceding paragraph may additionally and / or alternatively optionally include any one or more of the following features, configurations, and / or additional components.

[0052] For example, in some embodiments, the first electrode and the first non-conductive portion may form a relatively flat surface for contacting the tissue.

[0053] In some embodiments, the first electrode may be recessed within the first non-conductive portion and the first non-conductive portion may be located raised above the first electrode.

[0054] In some embodiments, the first electrode may be mounted within a recess in the first non-conductive portion, and the first electrode may be elevated above the first non-conductive portion.

[0055] In some embodiments, the first non-conductive portion may be flexible.

[0056] In some embodiments, the device may further include a second electrode, wherein the first electrode and the second electrode are configured to deliver electroporation therapy to tissue adjacent the first side of the electrode assembly.

[0057] In some embodiments, a second electrode may be disposed on a second side of the conformable electrode assembly opposite the first side.

[0058] In some embodiments, the second surface may include a second non-conductive portion, the second electrode may be attached to the second non-conductive portion and centrally disposed on the second surface, the second non-conductive portion may be defined by a third surface area, and the second electrode may be defined by a fourth surface area, the third surface area being greater than the fourth surface area.

[0059] In some embodiments, the second electrode can be a ring electrode disposed on the shaft.

[0060] In some embodiments, the device may further include a circuit board, and the first electrode may be attached to the circuit board, with the non-conductive portion surrounding the circuit board.

[0061] In some embodiments, the non-conductive portion can include an opening aligned with the first electrode, and the first electrode can be recessed relative to the non-conductive portion.

[0062] In some embodiments, the circuit board may be a flexible circuit board that includes a shape memory layer, the shape memory layer having a preset geometric shape.

[0063] In some embodiments, the pre-defined geometric shape may be one of a convex shape, a concave shape, and a planar shape.

[0064] In some embodiments, the first plurality of peripheral electrodes may be disposed on an outer periphery of the first surface of the conformable electrode assembly.

[0065] According to another aspect, a method of delivering electroporation therapy includes introducing a catheter shaft having an adaptable electrode assembly to a target location within a patient. The method may further include placing a first side of the adaptable electrode assembly in contact with the target tissue, the first side of the adaptable electrode assembly may include a first non-conductive portion and a first electrode centrally located on the first side, the first non-conductive portion surrounding the first electrode. The method may further include delivering an electroporation pulse to the first electrode.

[0066] The method of the preceding paragraph may additionally and / or alternatively optionally include any one or more of the following steps:

[0067] For example, in some embodiments, the method may further include measuring one or more signals using one or more of the first plurality of peripheral electrodes disposed on a first surface of the adaptable electrode assembly, determining whether the first surface of the adaptable electrode assembly is in contact with tissue based on the one or more measured signals, and repositioning the adaptable electrode assembly in response to determining that the adaptable electrode assembly is not in contact with tissue.

[0068] In some embodiments, the step of measuring the one or more signals may include measuring one or more of electrical activity in the tissue and impedance between one or more of the multiple peripheral electrodes.

[0069] In some embodiments, the method may further include measuring one or more signals using one or more of the first plurality of peripheral electrodes disposed on a first surface of the adaptable electrode assembly. The method may further include determining whether the delivered electroporation treatment was effective based on the one or more measured signals, and in response to determining that the delivered electroporation treatment was ineffective, repositioning the adaptable electrode assembly and delivering a next electroporation treatment.

[0070] According to another aspect, an electroporation treatment system may include a catheter and an electroporation generator. The catheter may further include a handle, an adaptable electrode assembly, and a shaft coupled to the handle at a proximal end and to the electrode assembly at a distal end. The adaptable electrode assembly may include a first surface and a second surface opposite the first surface, the first surface including a first non-conductive portion and a first electrode attached to the first non-conductive portion, the first electrode being centrally disposed, and the non-conductive portion surrounding the first electrode in a plane defined by the first surface. The electroporation generator may be coupled to the catheter to deliver electroporation pulses to the first electrode.

[0071] The electroporation treatment system of the preceding paragraph may additionally and / or alternatively optionally include any one or more of the following features, configurations, and / or additional components.

[0072] For example, in some embodiments, the conformable electrode assembly may further include a first plurality of peripheral electrodes disposed on an outer periphery of the first side of the conformable electrode assembly.

[0073] In some embodiments, the first electrode and the first plurality of electrodes may be disposed on a shape-memory flexible substrate having a preset geometric shape, and the conformable electrode assembly is configured to fit into a tube of the shaft.

Claims

1. 1. An electroporation device comprising: a shaft having a proximal end and a distal end; an electrode assembly disposed on the distal end of the shaft, the electrode assembly has a first surface, a second surface opposite and parallel to the first surface, and an outer surface surrounding the first surface and the second surface; the outer surface is connected to the distal end; the first surface includes a first non-conductive portion and a first electrode centrally disposed on the first surface; the first non-conductive portion is defined by a first surface area; the first electrode is defined by a second surface area; The first surface area is greater than the second surface area. The electrode assembly; An electroporation device comprising:

2. The electroporation device of claim 1 , wherein the first electrode and the first non-conductive portion form a relatively flat surface for contacting tissue.

3. the first electrode is recessed within the first non-conductive portion; The electroporation device of claim 1 or 2, wherein the first non-conductive portion is positioned higher than the first electrode.

4. the first electrode is attached to a recess in the first non-conductive portion; The electroporation device of claim 1 or 2, wherein the first electrode is positioned higher than the first non-conductive portion.

5. The electroporation device of claim 1 , wherein the first non-conductive portion is flexible.

6. further comprising a second electrode; 6. The electroporation device of claim 1, wherein the first electrode and the second electrode are configured to deliver electroporation therapy to tissue adjacent the first side of the electrode assembly.

7. The electroporation device of claim 6 , wherein the second electrode is disposed on the second surface.

8. the second surface includes a second non-conductive portion; the second electrode is attached to the second non-conductive portion and centrally disposed on the second surface; the second non-conductive portion is defined by a third surface area; the second electrode is defined by a fourth surface area; The electroporation device of claim 7 , wherein the third surface area is greater than the fourth surface area.

9. The electroporation device of claim 6 , wherein the second electrode is a ring electrode disposed on the shaft.

10. Further comprising a circuit board; the first electrode is attached to the circuit board; The electroporation device of claim 1 , wherein the first non-conductive portion surrounds the circuit board.

11. the first non-conductive portion includes an opening aligned with the first electrode; The electroporation device of claim 10 , wherein the first electrode is recessed relative to the first non-conductive portion.

12. The circuit board is a flexible circuit board including a shape memory layer, 12. The electroporation device of claim 10 or 11, wherein the shape memory layer has a preset geometric shape.

13. The electroporation device of claim 12 , wherein the pre-set geometric shape is one of a convex shape, a concave shape, and a planar shape.

14. 14. The electroporation device of claim 1, further comprising a first plurality of peripheral electrodes disposed on an outer edge of the first face of the electrode assembly.

15. 1. A method of operating a system for delivering electroporation therapy, comprising: the system includes the step of delivering an electroporation pulse to a first electrode of an electrode assembly, the electrode assembly having a first surface, a second surface opposite and parallel to the first surface, and an outer surface surrounding the first and second surfaces, the outer surface being connected to a distal end of a shaft, the first electrode being centrally disposed on the first surface of the electrode assembly, the first surface including a first non-conductive portion surrounding the first electrode, the first non-conductive portion being defined by a first surface area, the first electrode being defined by a second surface area, the first surface area being greater than the second surface area. How it works.

16. the system measuring one or more signals using one or more of a first plurality of peripheral electrodes disposed on the first surface of the electrode assembly; the system determining whether the first surface of the electrode assembly is in contact with tissue based on the measured one or more signals; The method of claim 15 further comprising:

17. 17. The method of claim 16, wherein the step of measuring one or more signals includes measuring one or more of: electrical activity in the tissue and impedance between one or more of the peripheral electrodes.

18. the system measuring one or more signals using one or more of the first plurality of peripheral electrodes disposed on the first surface of the electrode assembly; determining whether the delivered electroporation therapy was effective based on the measured one or more signals; 18. The method of claim 16 or 17, further comprising the system delivering a next electroporation therapy in response to determining that the delivered electroporation therapy was ineffective.

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