Electroporation ablation device

Abstract

To provide an electroporation ablation device.SOLUTION: Various aspects of the present disclosure are directed towards apparatuses, systems, and methods that may include an electroporation ablation device. The electroporation ablation device may include a shaft defining a longitudinal axis and an electrode assembly including a first pair of electrodes having a first electrode and a second electrode, and a second pair of electrodes disposed adjacent to the first pair of electrodes and having a third and a fourth electrode. In some embodiments, the first electrode has a first edge portion, and the first side view of the first edge portion along the longitudinal axis is rounded at a first corner.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to medical devices, systems, and methods for cardiac electropermeation ablation. More specifically, the present disclosure relates to a point pulse electric field ablation catheter.

Background Art

[0002] Ablation procedures are used to treat many different conditions in patients. Ablation can be used to treat cardiac arrhythmias, benign tumors, cancerous tumors, and to control bleeding during surgery. Typically, ablation is achieved by thermal ablation techniques including radiofrequency (RF) ablation and cryoablation. In RF ablation, a probe is inserted into the patient and radiofrequency is transmitted through the probe to the surrounding tissue. The radiofrequency generates heat, which destroys the surrounding tissue and cauterizes blood vessels. In cryoablation, a hollow needle or cryoprobe is inserted into the patient, and the surrounding tissue is frozen and killed by circulating a cryogenic heat-conductive fluid through the probe. RF ablation and cryoablation techniques kill tissue indiscriminately by cell necrosis, which can damage or kill otherwise healthy tissue such as tissue in the esophagus, phrenic nerve cells, and tissue in the coronary artery.

[0003] Another ablation technique uses electroporation. In electroporation or electropermeation treatment, an electric field is applied to cells to increase the permeability of the cell membrane. Electroporation can be reversible or irreversible depending on the strength of the electric field. When electroporation is reversible, the increased permeability of the cell membrane can be used to introduce chemicals, drugs, and / or deoxyribonucleic acid (DNA) into the cells before the cells heal and recover. When electroporation is irreversible, the affected cells die by apoptosis.

[0004] Irreversible electroporation (IRE) can be used as a non-thermal ablation technique. In IRE, a short train of high-voltage pulses is used to generate an electric field strong enough to kill cells by apoptosis. In the ablation of cardiac tissue, IRE can be a safe and effective alternative to the non-selective killing of thermal ablation techniques such as RF ablation and cryoablation. IRE can be used to kill target tissues such as myocardial tissue by using an electric field strength and duration that kill the target tissue but do not cause permanent damage to other cells and tissues such as non-target myocardial tissue, red blood cells, vascular smooth muscle tissue, endothelial tissue, and nerve cells.

Summary of the Invention

Problems to be Solved by the Invention

[0005] During IRE treatment, harmful events such as the formation of arcs or sparks can sometimes occur at higher output energies from the ablation catheter. The formation of arcs or sparks can cause tissue damage and increase the risk to the patient's treatment. There is a need for a method to prevent or reduce the formation of arcs or sparks during IRE treatment.

Means for Solving the Problems

[0006] In Example 1, the electroporation ablation device includes a shaft having an elongated body defining a longitudinal axis, the elongated body having a distal end and a proximal end, and an electrode assembly disposed on the shaft. The electrode assembly includes a first pair of electrodes including a first electrode and a second electrode disposed proximate to the distal end of the elongated body, and a second pair of electrodes disposed adjacent to the first pair of electrodes and including a third electrode and a fourth electrode. The first electrode includes a first edge portion substantially perpendicular to the longitudinal axis. The second electrode includes a second edge portion substantially perpendicular to the longitudinal axis and a third edge portion substantially perpendicular to the longitudinal axis. The first edge portion is closer to the second edge portion than the third edge portion. The first side view of the first edge portion along the longitudinal axis is rounded at a first corner having a first edge radius, and the second side view of the second edge portion is rounded at a second corner having a second edge radius.

[0007] In Example 2, the first electrode has a first electrode surface area, the second electrode has a second electrode surface area, and the difference between the first electrode surface area and the second electrode surface area is less than 20% of the first electrode surface area, which is the electroporation ablation device of Example 1.

[0008] In Example 3, the difference between the first electrode surface area and the second electrode surface area is less than 10% of the first electrode surface area, which is the electroporation ablation device of Example 2. In Example 4, the distance between the first edge portion and the second edge portion ranges from 1 millimeter to 2 millimeters, which is the electroporation ablation device of any one of Examples 1 to 3.

[0009] In Example 5, the distance between the first edge portion and the second edge portion ranges from 1.4 millimeters to 1.8 millimeters, which is the electroporation ablation device of any one of Examples 1 to 3.

[0010] In Example 6, the second electrode pair is a sensing electrode configured to measure an electrical signal and is disposed between the first electrode and the second electrode, and is an electroperforation ablation device according to any one of Examples 1 to 5.

[0011] In Example 7, the electrode assembly further includes a fifth ring electrode disposed further away from the distal end of the body that is longer and thinner than each electrode of the first electrode pair, and is an electroperforation ablation device according to any one of Examples 1 to 6.

[0012] In Example 8, the first electrode includes a conductive material having a first thickness, the first edge radius is associated with the first thickness, and the second electrode includes a conductive material having a second thickness, and the second edge radius is associated with the second thickness, and is an electroperforation ablation device according to any one of Examples 1 to 7.

[0013] In Example 9, a method for electroperforation ablation includes the step of disposing a point electroperforation catheter in proximity to a target tissue, the point electroperforation catheter comprising a shaft defining a longitudinal axis, a first electrode disposed in proximity to the distal end of the shaft, and a first electrode pair comprising a second electrode disposed in proximity to the first electrode, the first electrode having a first electrode surface area, the second electrode having a second electrode surface area, and the difference between the first electrode surface area and the second electrode surface area being less than 20% of the first electrode area; and generating, in the target tissue, an electric field having an electric field strength sufficient to ablate the target tissue via irreversible electroporation by the first electrode pair in response to a plurality of electrical pulse sequences delivered in a plurality of treatment sections.

[0014] In Example 10, the point electroperforation catheter further includes a second electrode pair disposed adjacent to the first electrode pair and including a third electrode and a fourth electrode, and is the method of Example 9. In Example 11, the method according to any one of Examples 9 to 10 further includes a step of collecting a sensing signal by a second pair of electrodes and a step of determining the position of the point electrical perforation catheter based on the collected sensing signal.

[0015] In Example 12, the first electrode includes a first edge portion substantially perpendicular to the longitudinal axis, the second electrode includes a second edge portion substantially perpendicular to the longitudinal axis and a third edge portion substantially perpendicular to the longitudinal axis, and the first edge portion is closer to the second edge portion than the third edge portion. The method according to any one of Examples 9 to 11.

[0016] In Example 13, the first cross-sectional shape of the first edge portion along the longitudinal axis is rounded at a first corner having a first edge radius. The method according to any one of Examples 9 to 12.

[0017] In Example 14, the second cross-sectional shape of the second edge portion along the longitudinal axis is rounded at a second corner having a second edge radius. The method according to any one of Examples 9 to 13.

[0018] In Example 15, the method according to any one of Examples 9 to 14 further includes a step of collecting a sensing signal by a second pair of electrodes and a step of determining the position of the point electrical perforation catheter based on the collected sensing signal.

[0019] In Example 16, the electroporation ablation device comprises a shaft having an elongated body defining a longitudinal axis, the elongated body having a distal end and a proximal end, and an electrode assembly disposed on the shaft. The electrode assembly includes a first pair of electrodes including a first electrode and a second electrode disposed adjacent to the distal end of the elongated body, and a second pair of electrodes disposed adjacent to the first pair of electrodes and including a third electrode and a fourth electrode. The first electrode includes a first edge portion substantially perpendicular to the longitudinal axis. The second electrode includes a second edge portion substantially perpendicular to the longitudinal axis and a third edge portion substantially perpendicular to the longitudinal axis. The first edge portion is closer to the second edge portion than the third edge portion. The first side view of the first edge portion along the longitudinal axis is rounded at a first corner having a first edge radius, and the second side view of the second edge portion is rounded at a second corner having a second edge radius.

[0020] In Example 17, the first electrode has a first electrode surface area, the second electrode has a second electrode surface area, and the difference between the first electrode surface area and the second electrode surface area is less than 20% of the first electrode surface area, which is the electroporation ablation device of Example 16.

[0021] In Example 18, the difference between the first electrode surface area and the second electrode surface area is less than 10% of the first electrode surface area, which is the electroporation ablation device of Example 16. In Example 19, the distance between the first edge portion and the second edge portion is in the range of 1 millimeter to 2 millimeters, which is the electroporation ablation device of Example 16.

[0022] In Example 20, the distance between the first edge portion and the second edge portion is within the range of 1.4 millimeters to 1.8 millimeters, which is the electroporation ablation device of Example 16.

[0023] In Example 21, the second pair of electrodes is a sensing electrode configured to measure an electrical signal, which is the electroporation ablation device of Example 16. In Example 22, the second electrode pair is the electroporation ablation device of Example 20, which is disposed between the first electrode and the second electrode.

[0024] In Example 23, the electrode assembly further includes a fifth ring electrode disposed further away from the distal end of the body that is more elongated than each electrode of the first electrode pair, and is the electroporation ablation device of Example 16.

[0025] In Example 24, the first electrode includes a conductive material having a first thickness, and the first edge radius is associated with the first thickness, and is the electroporation ablation device of Example 16.

[0026] In Example 25, the second electrode includes a conductive material having a second thickness, and the second edge radius is associated with the second thickness, and is the electroporation ablation device of Example 16.

[0027] In Example 26, a method for electroporation ablation includes the step of disposing a point electroporation catheter in proximity to a target tissue, the point electroporation catheter comprising a shaft defining a longitudinal axis and a first electrode pair, the first electrode pair comprising a first electrode disposed in proximity to the distal end of the shaft and a second electrode disposed in proximity to the first electrode, the first electrode having a first electrode surface area and the second electrode having a second electrode surface area, and the difference between the first electrode surface area and the second electrode surface area being less than 20% of the first electrode area; and generating, in the target tissue, an electric field having an electric field strength sufficient to ablate the target tissue via irreversible electroporation by the first electrode pair in response to a plurality of electrical pulse sequences delivered in a plurality of treatment sections.

[0028] In Example 27, the point electroporation catheter is disposed adjacent to the first electrode pair and further includes a second electrode pair including a third electrode and a fourth electrode, and is the method of Example 26.

[0029] Example 28 is the method of Example 27, further including the step of collecting a sensing signal by a second pair of electrodes. Example 29 is the method of Example 28, further including the step of determining the position of the point electrical perforation catheter based on the collected sensing signal.

[0030] Example 30 is the method of Example 26, wherein the first electrode includes a first edge portion substantially perpendicular to the longitudinal axis. Example 31 is the method of Example 30, wherein the second electrode includes a second edge portion substantially perpendicular to the longitudinal axis and a third edge portion substantially perpendicular to the longitudinal axis.

[0031] Example 32 is the method of Example 31, wherein the first edge portion is closer to the second edge portion than the third edge portion. Example 33 is the method of Example 32, wherein the first cross-sectional shape of the first edge portion along the longitudinal axis is rounded at a first corner having a first edge radius.

[0032] Example 34 is the method of Example 33, wherein the second cross-sectional shape of the second edge portion is rounded at a second corner having a second edge radius. In Example 35, an electroporation ablation system for treating a patient's target tissue comprises an electroporation ablation device. The electroporation ablation device comprises a shaft having an elongated body defining a longitudinal axis, the elongated body having a distal end and a proximal end, and an electrode assembly disposed on the shaft. The electrode assembly includes a first pair of electrodes including a first electrode and a second electrode disposed proximate the distal end of the elongated body, and a second pair of electrodes disposed adjacent the first pair of electrodes and including a third electrode and a fourth electrode. The first electrode includes a first edge portion substantially perpendicular to the longitudinal axis. The second electrode includes a second edge portion substantially perpendicular to the longitudinal axis and a third edge portion substantially perpendicular to the longitudinal axis. The first edge portion is closer to the second edge portion than to the third edge portion. A first side view of the first edge portion along the longitudinal axis is rounded at a first corner having a first edge radius, and a second side view of the second edge portion is rounded at a second corner having a second edge radius. The electroporation ablation system further comprises a controller configured to receive one or more signals from one or more mapping electrodes, and an electroporation generator operably coupled to the electrode assembly and the controller.

[0033] Although a plurality of embodiments are disclosed, further other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description which illustrates and describes exemplary embodiments of the present invention. Accordingly, the drawings and the detailed description are to be regarded as illustrative in nature and not as restrictive.

Advantages of the Invention

[0034] According to the present invention, an electroporation ablation device can be provided.

Brief Description of the Drawings

[0035]

Figure 1

Figure 2A

Figure 2B

Figure 2C

Figure 3

Figure 4

Figure 5

DETAILED DESCRIPTION OF THE INVENTION

[0036] The present invention is subject to various modifications and alternative forms, but specific embodiments are shown by way of example in the drawings and will be described in detail below. However, the intention is not to limit the present invention to the specific embodiments described. On the contrary, the present invention is intended to embrace all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claims.

[0037] The following detailed description is exemplary in nature and is in no way intended to limit the scope, applicability, or configuration of the present invention. Rather, the following description provides some practical illustrations for implementing exemplary embodiments of the present invention. Examples of configurations, materials, and / or dimensions are provided for selected elements. Those skilled in the art will recognize that many of the described examples have various suitable alternatives.

[0038] As used herein with respect to measurements (e.g., dimensions, characteristics, attributes, components, etc.) and ranges thereof of tangible things (e.g., products, inventory, etc.) and / or intangible things (e.g., data, electronic representations of currency, accounts, information, portions of things (e.g., percentages, ratios), calculations, data models, dynamic system models, algorithms, parameters, etc.), the terms “about” and “approximately” include the recited measurements and any measurements that include the recited measurements and that can vary by a reasonably small amount that is reasonably close to the recited measurements but that would be understood by one of ordinary skill in the art and readily confirmed as being due to measurement error, differences in measurement and / or manufacturing equipment calibration, human error in reading and / or setting of measurements, adjustments made to optimize performance and / or structural parameters in view of other measurements (e.g., measurements related to other things), inaccurate adjustments and / or manipulations of things, settings, and / or measurements by particular implementation scenarios, people, computing devices, and / or machines, system tolerances, control loops, machine learning, predictable variations (e.g., statistically insignificant variations, chaotic variations, system and / or model instabilities, etc.), preferences, etc. and can be used interchangeably to refer to such.

[0039] Exemplary methods may be represented by one or more drawings (e.g., flow diagrams, communication flows, etc.), but the drawings should not be construed as implying any requirements for the various steps disclosed herein or a particular order between them. However, some specific embodiments may require specific steps and / or a particular order between specific steps, as may be explicitly described herein and / or as may be understood from the nature of the steps themselves (e.g., the performance of some steps may depend on the results of previous steps). Additionally, a “set,” “subset,” or “group” of items (e.g., inputs, algorithms, data values, etc.) may include one or more items, and similarly, a subset or subgroup of items may include one or more items. “Plurality” means two or more.

[0040] As used herein, the term "based on" does not mean limiting, but rather indicates that determinations, identifications, predictions, calculations, etc. are performed by using, at least, the terms following "based on" as inputs. For example, predicting a result based on certain information can additionally or alternatively be made to be based on different information for the same determination.

[0041] Irreversible electroporation (IRE) uses high voltage short (e.g., 100 microseconds or less) pulses to kill cells by apoptosis. IRE can be targeted to kill myocardium while sparing other adjacent tissues including esophageal vascular smooth muscle and endothelium. During the process of the IRE therapy section, adverse events such as arc or spark formation may occur. The therapy section can include a treatment burst period and a rest period. The therapy section (e.g., having a duration of about 10 milliseconds) is continuously generated and delivered by an electroporation generator and can include a plurality of electrical pulses (e.g., 20 pulses, 30 pulses, etc.), also referred to as a treatment burst. The treatment burst period refers to the period of the treatment burst, and the rest period refers to the period without the treatment burst. In some examples, an arc or spark can occur during the treatment burst period. The formation of an arc or spark can cause tissue damage and increase the risk to the patient's treatment.

[0042] At least some embodiments of the present disclosure are directed to a point electroporation ablation catheter design for reducing or preventing arc formation during IRE ablation. In some embodiments, an electroporation ablation system includes a point electroporation ablation catheter designed to reduce or prevent arc formation during IRE ablation. As used herein, a point catheter refers to a catheter having a linear body carrying an ablation electrode. In an embodiment, the point catheter has an ablation electrode towards its distal end.

[0043] FIG. 1 is a diagram showing an exemplary clinical setting 10 for treating patient 20 and treating the heart 30 of patient 20 using an electrophysiology system 50 in accordance with an embodiment of the subject matter of the present disclosure. The electrophysiology system 50 includes an electroporation device 60 and an optional localization field generator 80. The clinical setting 10 also includes additional devices such as an imaging device 94 (represented by a C-arm), and various controller elements configured to enable an operator to control various aspects of the electrophysiology system 50. As will be understood by those skilled in the art, the clinical setting 10 may have other components and arrangements of components not shown in FIG. 1.

[0044] The electroporation device 60 includes an electroporation catheter 105, an introducer sheath 110, a controller 90, and an electroporation generator 130. In an embodiment, the electroporation device 60 is configured to deliver electric field energy to target tissue within the patient's heart 30 to cause tissue apoptosis and render the tissue non-conductive to electrical signals. The controller 90 is configured to control the functional aspects of the electroporation device 60. In an embodiment, the controller 90 is configured to control the electroporation generator 130 to generate electrical pulses, such as the magnitude of the electrical pulse, the timing and duration of the electrical pulse. In an embodiment, the electroporation generator 130 is operable as a pulse generator to generate a pulse sequence and supply it to the electroporation catheter 105.

[0045] In an embodiment, the introducer sheath 110 is operable to provide a delivery conduit through which the electroporation catheter 105 can be deployed to a specific target site within the patient's heart 30. However, it will be understood that the introducer sheath 110 is illustrated and described herein for the purpose of providing context to the overall electrophysiology system 50.

[0046] In the illustrated embodiment, the electroporation catheter 105 includes a handle 105a, a shaft 105b, and an electrode assembly 150. The handle 105a is configured to be manipulated by a user to position the electrode assembly 150 at a desired anatomical location. The shaft 105b has a distal end 105c and generally defines the longitudinal axis of the electroporation catheter 105. As shown, the electrode assembly 150 is located at or near the distal end 105c of the shaft 105b. In an embodiment, the electrode assembly 150 is electrically coupled to an electroporation generator 130 to receive an electrical pulse sequence or train of pulses, thereby selectively generating an electric field for ablating target tissue by irreversible electroporation.

[0047] In certain embodiments, the electroporation catheter 105 is a point catheter that includes a linear body toward the distal end. In an embodiment, the electrode assembly 150 includes one or more electrodes disposed on the shaft 105b. In some implementations, the electrode assembly 150 includes one or more electrode pairs. In some embodiments, the electrode assembly 150 includes one or more ablation electrodes and one or more sensing electrodes. In a particular embodiment, the electrode assembly 150 includes a pair of ablation electrodes configured to generate an electric field sufficient for irreversible electroporation ablation. In some examples, the ablation electrode pair includes a cap electrode covering an end cap at the distal end of the catheter 105 and a ring electrode disposed proximate to the cap electrode. As used herein, the ring electrode refers to an electrode having a ring shape. In some designs, the cap electrode and the ring electrode include an edge radius (e.g., a rounded edge) at one or more edges, for example, to reduce arcing. In some designs, the pair of ablation electrodes includes two ring electrodes disposed proximate to the distal end of the catheter 105.

[0048] In a particular design, a pair of ablation electrodes are spaced at a selected distance, for example, to form a relatively uniform electric field while reducing arc discharge. In some embodiments, the selected distance is about 1 to 2 millimeters. In a particular embodiment, the selected distance is about 1.4 to 1.8 millimeters. In some examples, the selected distance is greater than a predetermined lower threshold distance (e.g., 0.5 millimeter), for example, to reduce arc discharge. In a particular example, the selected distance is less than a predetermined upper threshold distance (e.g., 3 millimeters), for example, to generate a substantially uniform electric field. If the distance between a pair of ablation electrodes is substantially greater than the predetermined upper threshold distance, the electric field generated by the ablation electrodes may not be uniform.

[0049] In embodiments, the position and size of the electrodes are specifically designed to allow flexibility. For example, the electrodes are designed to have a relatively short length. As another example, the two electrodes have a relatively large spacing to allow flexibility and / or bending. In some examples, one or more electrodes include one or more pairs of ablation electrodes and one or more pairs of sensing electrodes. The sensing electrodes may be used to sense electrical signals related to the patient's heart, which allows an operator or system to determine whether ablation has occurred. In some designs, electrical signals can be used to determine the position or proximity of the electropermeabilization catheter 105.

[0050] In some embodiments, one or more sensing electrodes on the electroperforation catheter 105 can measure electrical signals and generate output signals that can be processed by a controller (e.g., controller 90) to generate an electroanatomical map. In some examples, the electroanatomical map is generated prior to ablation to determine the electrical activity of the heart tissue within the target heart chamber. In some examples, the electroanatomical map is generated after ablation to verify the desired changes in the electrical activity of the ablated tissue and the entire heart chamber. The sensing electrodes can be used to determine the position of the catheter 105 in the three-dimensional space within the body. For example, when an operator moves the catheter 105 within a patient's heart chamber, the boundaries of the catheter movement can be determined by the controller 90, which can include or be coupled to a mapping and navigation system to form the anatomical structure of the heart chamber. The chamber anatomy can be used to facilitate navigation of the catheter 105 without using ionizing radiation such as fluoroscopy, and to tag the ablation positions when ablation is complete to guide the ablation intervals and help the operator completely ablate the targeted anatomical structure.

[0051] In some embodiments, other sensors such as force sensors, degree-of-freedom (「DoF」) sensors, etc. are disposed between the electrodes. In some implementation forms, the ablation electrode pair includes two electrodes having similar electrode surface areas. For example, the electrode area of the cap electrode includes the surface area at the end face. In some embodiments, the two ablation electrodes of the ablation electrode pair have a surface area difference within 50% of one of the electrode surface areas. In certain embodiments, the two ablation electrodes of the ablation electrode pair have a surface area difference within 30% of one of the electrode surface areas. In some embodiments, the two ablation electrodes of the ablation electrode pair have a surface area difference within 20% of one of the electrode surface areas. In certain embodiments, the two ablation electrodes of the ablation electrode pair have a surface area difference within 10% of one of the electrode surface areas.

[0052] In certain embodiments, one or more electrodes include sensing electrodes that are smaller in size than the ablation electrodes. In one example, each of the sensing electrodes has an electrode surface area that is 50% or less of the surface area of the ablation electrode. In another example, each of the sensing electrodes has an electrode surface area that is 50% or less of the surface area of each of the plurality of ablation electrodes.

[0053] According to embodiments, various components of the electrophysiological system 50 (e.g., the controller 90) may be implemented on one or more computing devices. The computing device can include any type of computing device suitable for implementing the embodiments of the present disclosure. Examples of computing devices include workstations, servers, laptops, portable devices, desktops, tablet computers, handheld devices, dedicated computing devices such as general-purpose graphics processing units (GPGPUs), or general-purpose computing devices, all of which are intended to be within the scope of FIG. 1 with reference to the various components of the system 50.

[0054] In some embodiments, a computing device includes the following devices: a processor, a memory, input / output (I / O) ports, I / O components, and a bus that directly and / or indirectly couples the power supply. Any number of additional components, different components, and / or combinations of components may also be included in the computing device. The bus may represent one or more buses (e.g., an address bus, a data bus, or a combination thereof). Similarly, in some embodiments, a computing device may include several processors, several memory components, several I / O ports, several I / O components, and / or several power supplies. Additionally, any number of these components or combinations thereof may be distributed and / or replicated across several computing devices.

[0055] In some embodiments, system 50 includes one or more memories (not shown). The one or more memories include computer-readable media in the form of volatile and / or non-volatile memory, temporary and / or non-temporary storage media, and may be removable, non-removable, or a combination thereof. Examples of media include random access memory (RAM), read only memory (ROM), electronically erasable programmable read only memory (EEPROM), flash memory, optical or holographic media, magnetic cassettes, magnetic tapes, magnetic disk storage devices or other magnetic storage devices, data transmission, and / or any other media that can be used to store information and can be accessed by a computing device, such as quantum state memory. In some embodiments, the one or more memories store computer-executable instructions for causing a processor (e.g., controller 90) to implement aspects of the embodiments of the system components discussed herein and / or to execute aspects of the embodiments of the methods and procedures discussed herein.

[0056] Computer-executable instructions can include, for example, computer code, machine-usable instructions, etc., such as program components that can be executed by one or more processors associated with a computing device. The program components can be programmed using any number of different programming environments, including various languages, development kits, frameworks, etc. Some or all of the functions contemplated herein can also or alternatively be implemented in hardware and / or firmware.

[0057] In some embodiments, the memory may include a data repository that can be implemented using any one of the configurations described below. The data repository may include random access memory, flat files, XML files, and / or one or more database management systems (DBMSs) running on one or more database servers or data centers. The database management system may be a relational (RDBMS), hierarchical (HDBMS), multidimensional (MDBMS), object-oriented (ODBMS or OODBMS), or object-relational (ORDBMS) database management system, etc. The data repository may be, for example, a single relational database. In some cases, the data repository may include multiple databases that can exchange and aggregate data by a data integration process or software application. In an exemplary embodiment, at least a portion of the data repository may be hosted in a cloud data center. In some cases, the data repository may be hosted on a single computer, server, storage device, cloud server, etc. In some other cases, the data repository may be hosted on a series of networked computers, servers, or devices. In some cases, the data repository may be hosted in a tier of data storage devices including local, regional, and central.

[0058] The various components of system 50 may communicate or be connected via a communication interface, e.g., a wired or wireless interface. The communication interface may include, but is not limited to, any wired or wireless short-range and long-range communication interfaces. For the wired interface, cables, umbilicals, etc. can be used. The short-range communication interface may conform to known communication standards such as, for example, those based on local area network (LAN), Bluetooth® standard, IEEE 802 standards (e.g., IEEE 802.11), ZigBee® or similar specifications such as those based on the IEEE 802.15.4 standard, or other public or proprietary wireless protocols. The long-range communication interface may be, for example, a wide area network (WAN), a cellular network interface, a satellite communication interface, etc. The communication interface may be within a private computer network such as an intranet or on a public computer network such as the Internet.

[0059] Figures 2A - 2C are an exposed side view, a side view, and a perspective view, respectively, of a schematic diagram of an exemplary point electrical perforation ablation catheter 200, according to an embodiment of the subject matter of the present disclosure. As shown, the electrode assembly 202 is axially disposed along the longitudinal axis 204 of the shaft 206 of the ablation catheter 200. The electrode assembly 202 includes a first electrode pair 208 and a second electrode pair 210. The first electrode pair 208 can include a first electrode 212 and a second electrode 214 disposed proximate the distal end of the shaft 206. The second electrode pair 210 can include a third electrode 216 and a fourth electrode 218. The first electrode 212 has a first edge 220 that is substantially perpendicular to the longitudinal axis 204. The second electrode 214 has a second edge 222 and a third edge 224, both of which are substantially perpendicular to the longitudinal axis 204. In embodiments, the first and second edges 220, 222 are substantially parallel to each other and perpendicular to the longitudinal axis 204 such that the electrodes 212, 214 are coaxially aligned with each other. Electrodes disposed out of alignment can increase the chance of arc formation.

[0060] In embodiments, the first edge 220 of the first electrode 212 is closer to the second edge 222 of the second electrode 214 than the third edge 224 of the second electrode 214. In embodiments, the first electrode 212 has a first edge portion 213 that includes the first edge 220 and a first edge radius 234, and the first edge 220 is substantially perpendicular to the longitudinal axis 204. In embodiments, the first electrode 212 has a first cross-sectional shape (not shown) of the first edge portion 213, the cross-sectional shape generally follows along the longitudinal axis 204, and is rounded at the first corner 226.

[0061] In embodiments, the second electrode 214 has a second edge portion 215 that includes the second edge 222 and a second edge radius 236. In embodiments, the second edge 222 has a second cross-sectional shape (not shown) of the second edge portion 215, the second cross-sectional shape generally follows along the longitudinal axis 204, and is rounded at the second corner 228. The first and second edge radii 234, 236 vary according to the thickness of the materials used for the first and second electrodes 212, 214. The rounded shape at the corners 226, 228 can reduce the chance of arc formation during treatment.

[0062] In some embodiments, the first electrode 212 includes a conductive material having a first thickness, and the first edge radius is associated with the first thickness. Optionally, the first thickness may be about 0.0762 to 0.1524 millimeters (or 0.003 to 0.006 inches). In some embodiments, the second electrode 214 includes a conductive material having a second thickness, and the second edge radius is associated with the second thickness. Optionally, the second thickness may be about 0.0762 to 0.1524 millimeters (or 0.003 to 0.006 inches).

[0063] The first electrode 212 has a first electrode surface area, and the second electrode 214 has a second electrode surface area. In an embodiment, the difference between the first electrode surface area and the second electrode surface area is less than 50% of the first electrode surface area. In one embodiment, the difference between the first electrode surface area and the second electrode surface area is less than 20% of the first electrode surface area. In some embodiments, the difference between the first electrode surface area and the second electrode surface area is less than 10% of the first electrode surface area. The difference between the first electrode surface area and the second electrode surface area can be useful for reducing arc discharge. This is because the greater the difference between the two surface areas, the higher the likelihood that an arc or spark will be formed during treatment. In other words, equal surface areas between the two electrodes prevent arc formation. However, since energy tends to go towards the smaller surface area, a small offset or difference between the surface areas is required to conduct the current necessary for treatment.

[0064] In some embodiments, the distance 232 between the first edge 220 and the second edge 222 ranges from 1 to 2 millimeters. In some embodiments, the distance between the first edge 220 and the second edge 222 is within the range of 1.4 to 1.8 millimeters. In some embodiments, the distance between the first edge 220 and the second edge 222 is about 1.6 millimeters. If the distance 232 is too small, the risk of arc or spark formation increases. If the distance 232 is too large, the risk of non-uniform lesion formation increases. In other words, if the distance 232 is too large, the electric field generated by the electrodes 212, 214 may become non-uniform, which has an adverse effect on IRE treatment.

[0065] In some embodiments, the second electrode pair 210 may be a sensing electrode configured to measure an electrical signal. In other embodiments, the second electrode pair 210 may also be an ablation electrode connected to an electroporation generator. In some cases, the second electrode pair 210 may be configured to measure local impedance and act as a magnetic sensor for mapping the local electric field with five degrees of freedom (e.g., five different motions - x, y, z, acceleration, and rotation).

[0066] Because a force sensor is disposed between the electrodes 214 and 244, the distance between the third edge 224 and the fourth edge 242 of the distal electrode 244 of the second electrode pair 210 may be about 4.5 millimeters. In embodiments, the catheter may include a force sensor (not shown) disposed between the electrodes 214 and 244 and configured to sense the force of the local electric field. In embodiments, the catheter does not include a force sensor, and the gap between the third edge 224 and the fourth edge 242 of the distal electrode 244 of the second electrode pair 210 may be less than 4.5 millimeters. The force sensor is configured to measure force when the tip of the catheter 200 is in contact with the patient's tissue, which may provide feedback to the operator or the system regarding whether the catheter tip is in proximity to the tissue being treated. The addition of a force sensor and force information at the catheter tip can also help the operator avoid perforating the heart tissue and thus can serve a safety purpose.

[0067] The distance 252 between the fifth edge 246 of the third electrode 216 and the sixth edge 248 of the fourth electrode 250 may be from 0.5 mm to 4.5 mm. In some embodiments, the distance 252 may be from 1 to 2 mm. In some embodiments, the distance 252 may be 1.6 mm. In some embodiments, the distance 252 may be within 10% of the diameter of the electrodes 216, 218, which is 2.79 mm.

[0068] In some embodiments, the first and second electrode pairs may have a surface finish with a roughness of up to 0.0008 millimeters (or 30 microinches) RA (“arithmetic average roughness”). Optionally, the conductive material may include 90% platinum and 10% Aradium (trademark).

[0069] The electrode assembly 202 is connected to an electroporation generator (e.g., the electroporation generator 130 of FIG. 1) via one or more conductor wires 238. The location where the wire 238 is connected to the electrodes 212, 214 is not critically important for the present invention. In embodiments, the conductor wire is made of metal, and the exposed points of the metal are covered between the electrodes 212, 214 to prevent arc formation. In some embodiments, the conductor wire is made of copper with nickel plating or coating to provide good electrical conductivity properties. Copper may be prone to corrosion, but the corrosion can produce an oxide layer for better electrical conductivity quality. In some cases, the conductor wire can include steel. In some cases, the conductor wire can include solid nickel.

[0070] The ablation catheter 200 is constructed to withstand generator output energy from an electroporation generator of up to 3000 volts direct current (VDC). In some cases, a dielectric material is used to insulate the electrodes 212, 214, 216, and 218 (e.g., injection molding a plurality of polymers and adhesive layers for insulation) to prevent current leakage. Each conductor wire may be insulated from another conductor or electrode using a polymeric insulator (e.g., polyimide, polyether ether ketone (PEEK), thermoplastic elastomer, polycarbonate, or nylon). In some embodiments, the insulation layer has redundancy to ensure dielectric strength if one of the insulators is damaged.

[0071] In some embodiments, the electrode assembly 202 includes a fifth ring electrode 230 disposed further away from the distal end of the shaft 206 of the ablation catheter 200 than each electrode of the first electrode pair 208. The distance between the third edge 224 of the first electrode pair 208 and the ring electrode 230 may be about 4.5 mm. In some embodiments, the steering ring may be disposed proximal to the fifth electrode 230 along the longitudinal axis 204. The steering ring (e.g., the fifth electrode 230) is configured to assist in deflecting the distal tip of the catheter 200.

[0072] In some embodiments, there may be more than five electrodes (e.g., six, seven, or more). In some cases, the additional electrodes may be configured to add additional ablation vectors / configurations (e.g., different cathode / anode pairings or selection options) to change the shape of the generated electric field. In some cases, the additional electrodes may be configured for different sensing capabilities, including sensing the electrical activity of the heart, and / or for use in mapping the electrical activity or anatomical structure of the heart.

[0073] In some embodiments, the catheter 200 may include a navigation sensor 240 disposed at the distal end of the shaft 206 inside the first electrode 212. The navigation sensor 240 is configured to sense the movement and position of the distal end of the catheter 200 in five degrees of freedom / movement.

[0074] FIG. 3 is a schematic side view of an exemplary point electrical perforation ablation catheter 300 according to an embodiment of the subject matter of the present disclosure. The ablation catheter 300 may include a first electrode pair 308 and a second electrode pair 310. The first electrode pair 308 can include a first electrode 312 and a second electrode 314. The second electrode pair 310 can include a third electrode 316 and a fourth electrode 318. In some embodiments, as shown, the second electrode pair 310 may be disposed between the first electrode 312 and the second electrode 314. In some embodiments, the first electrode pair 308 may be ablation electrodes, and the second electrode pair may be sensing electrodes. In some embodiments, both the first electrode pair and the second electrode pairs 308, 310 may be ablation electrodes, and one or more additional electrodes may be added for the purposes described above (e.g., to add additional ablation vectors / configurations, or for different sensing capabilities including sensing cardiac electrical activity, and / or for use in mapping cardiac electrical activity or anatomical structures).

[0075] FIG. 4 shows exemplary electric fields of a point electrical perforation ablation catheter according to an embodiment of the subject matter of the present disclosure. The electric field 401 is generated by the first pair of electrodes 412, 414 at 1000 volts. The electric field 403 is generated by the first pair of electrodes 412, 414 at 2000 volts. As shown, the electric field 403 is larger in size compared to the electric field 414 due to the higher voltage. The shape of both electric fields 401, 403 is relatively uniform, e.g., the electric field strength is approximately equal with respect to the distance to either electrode (e.g., approximately the same electric field strength for regions having approximately the same distance from the electrode), as a result, arc discharge is reduced. As shown, the electric field does not have a clear gap between the two electric fields generated by the electrodes 412, 414, or a significant difference in electric field strength with respect to the distance to the electrodes.

[0076] FIG. 5 is a flow diagram showing a method 500 for treating a target tissue using an electroporation catheter, according to an embodiment of the subject matter of the present disclosure. Aspects of embodiments of method 500 may be performed, for example, by an electroporation ablation system / device (e.g., system / device 50 shown in FIG. 1). One or more steps of method 500 are optional and / or may be modified by one or more steps of other embodiments described herein. Additionally, one or more steps of other embodiments described herein may be added to method 500.

[0077] In some embodiments, method 500 includes placing a point electroporation catheter proximate to the target tissue (505) and delivering an electrical pulse to the electrodes of the point electroporation catheter (510). In some examples, the point electroporation catheter includes a shaft defining a longitudinal axis and a first electrode pair, the first electrode pair including a first electrode disposed proximate to the distal end of the shaft and a second electrode disposed proximate to the first electrode. In a particular example, the first electrode has a first electrode surface area and the second electrode has a second electrode surface area. In one example, the difference between the first electrode surface area and the second electrode surface area is less than 50% of the first electrode area. In one example, the difference between the first electrode surface area and the second electrode surface area is less than 20% of the first electrode area. In one example, the difference between the first electrode surface area and the second electrode surface area is less than 10% of the first electrode area.

[0078] Method 500 may further include generating an electric field for ablation by at least one pair of electrodes, e.g., by the first electrode pair (515). In an embodiment, the electric field is generated by the first electrode pair proximate to the target tissue in response to a plurality of electrical pulse sequences delivered in a plurality of treatment sections, and the electric field has an electric field strength sufficient to ablate the target tissue via irreversible electroporation.

[0079] In an embodiment, the first electrode has a first edge portion substantially perpendicular to the longitudinal axis, and the second electrode includes a second edge portion substantially perpendicular to the longitudinal axis and a third edge portion substantially perpendicular to the longitudinal axis. In some cases, the first edge portion is closer to the second edge portion than the third edge portion. In some embodiments, the first cross-sectional shape of the first edge portion along the longitudinal axis is rounded at a first corner having a first edge radius, and the second cross-sectional shape of the second edge portion is rounded at a second corner having a second edge radius.

[0080] In an embodiment, the point electrical perforation catheter further includes a second pair of electrodes disposed adjacent to the first pair of electrodes and including a third electrode and a fourth electrode. In some examples, the second pair of electrodes are sensing electrodes. In a particular example, the second pair of electrodes are ablation electrodes. Method 500 may include, for example, step (520) of collecting a sensing signal by a sensing electrode on the catheter using the second pair of electrodes. In some embodiments, method 500 includes determining the position of the catheter based on the collected sensing signal (525). For example, the sensing electrode may be part of a position tracking system. In one example, the sensing electrode can be used to measure local impedance that can be used to determine the location of the catheter. In some embodiments, the method includes generating an electroanatomical map based on the collected sensing signal. The sensing electrode may collect sensing signals before and / or after ablation.

[0081] Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the invention. For example, although the above embodiments refer to specific features, the scope of the invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the invention is intended to encompass all such alternative, modified, and variant forms, together with all of their equivalents, that fall within the scope of the claims.

[0082] The technical ideas that can be grasped from the above embodiments are described below as appendices. [Appendix 1] An electroporation ablation device comprising a shaft having an elongated body defining a longitudinal axis, the elongated body having a distal end and a proximal end, and an electrode assembly disposed on the shaft, a first pair of electrodes including a first electrode disposed adjacent to the distal end of the elongated body and a second electrode, and a second pair of electrodes disposed adjacent to the first pair of electrodes and including a third electrode and a fourth electrode, wherein the first electrode has a first edge portion substantially perpendicular to the longitudinal axis, the second electrode has a second edge portion substantially perpendicular to the longitudinal axis and a third edge portion substantially perpendicular to the longitudinal axis, the first edge portion is closer to the second edge portion than the third edge portion, a first side view of the first edge portion along the longitudinal axis is rounded at a first corner having a first edge radius, a second side view of the second edge portion is rounded at a second corner having a second edge radius, An electroporation ablation device.

[0083] [Appendix 2] The first electrode has a first electrode surface area, the second electrode has a second electrode surface area, The electroporation ablation device according to Appendix 1, wherein a difference between the first electrode surface area and the second electrode surface area is less than 20% of the first electrode surface area.

[0084] [Appendix 3] The electroporation ablation device according to Appendix 2, wherein a difference between the first electrode surface area and the second electrode surface area is less than 10% of the first electrode surface area. [Appendix 4] The electrical perforation ablation device according to any one of Appendices 1 to 3, wherein the distance between the first edge portion and the second edge portion is within the range of 1 millimeter to 2 millimeters.

[0085] [Appendix 5] The electrical perforation ablation device according to any one of Appendices 1 to 3, wherein the distance between the first edge portion and the second edge portion is within the range of 1.4 millimeters to 1.8 millimeters.

[0086] [Appendix 6] The electrical perforation ablation device according to any one of Appendices 1 to 5, wherein the second electrode pair is a sensing electrode configured to measure an electrical signal. [Appendix 7] The electrical perforation ablation device according to any one of Appendices 1 to 6, wherein the electrode assembly further comprises a fifth ring electrode disposed further away from the distal end of the elongated body than each electrode of the first electrode pair.

[0087] [Appendix 8] The first electrode includes a conductive material having a first thickness, and the first edge radius is associated with the first thickness. The second electrode includes a conductive material having a second thickness, and the second edge radius is associated with the second thickness. The electrical perforation ablation device according to any one of Appendices 1 to 7.

[0088] [Appendix 9] A method for electrical perforation ablation, the method comprising: Placing a point electrical perforation catheter in proximity to a target tissue, the point electrical perforation catheter comprising a shaft defining a longitudinal axis and a first electrode pair, the first electrode pair comprising a first electrode disposed in proximity to the distal end of the shaft and a second electrode disposed in proximity to the first electrode, the first electrode having a first electrode surface area, the second electrode having a second electrode surface area, and the difference between the first electrode surface area and the second electrode surface area being less than 20% of the first electrode area. Generating, by the first electrode pair, an electric field in the target tissue in response to a plurality of electrical pulse sequences delivered in a plurality of treatment sections, wherein the electric field has an electric field strength sufficient to ablate the target tissue via irreversible electroporation; A method comprising.

[0089] [Appendix 10] The method according to Appendix 9, wherein the point electroporation catheter is disposed adjacent to the first electrode pair and further includes a second electrode pair including a third electrode and a fourth electrode.

[0090] [Appendix 11] The method according to Appendix 9 or Appendix 10, further comprising collecting a sensing signal by the second electrode pair and determining a position of the point electroporation catheter based on the collected sensing signal.

[0091] [Appendix 12] The first electrode comprises a first edge portion substantially perpendicular to the longitudinal axis; The second electrode comprises a second edge portion substantially perpendicular to the longitudinal axis and a third edge portion substantially perpendicular to the longitudinal axis; The first edge portion is closer to the second edge portion than the third edge portion. The method according to any one of Appendices 9 to 11.

[0092] [Appendix 13] The first cross-sectional shape of the first edge portion along the longitudinal axis is rounded at a first corner having a first edge radius. The method according to any one of Appendices 9 to 12.

[0093] [Appendix 14] The second cross-sectional shape of the second edge portion along the longitudinal axis is rounded at a second corner having a second edge radius. The method according to any one of Appendices 9 to 13.

[0094] [Appendix 15] The method according to any one of Appendices 9 to 14 further: collecting a sensing signal by the second electrode pair; and determining a position of the point electrical perforation catheter based on the collected sensing signal; A method comprising the steps.

Claims

1. An irreversible electroporation ablation device, comprising: a shaft having an elongated body defining a longitudinal axis, the elongated body having a distal end and a proximal end; an electrode assembly disposed on the shaft, the electrode assembly including a first electrode pair including a first electrode disposed adjacent to the distal end of the elongated body and a second electrode, and a second electrode pair disposed adjacent to the first electrode pair and including a third electrode and a fourth electrode; wherein the first electrode includes a first edge portion substantially perpendicular to the longitudinal axis, the second electrode includes a second edge portion substantially perpendicular to the longitudinal axis and a third edge portion substantially perpendicular to the longitudinal axis, the first edge portion is closer to the second edge portion than the third edge portion, a first side view of the first edge portion along the longitudinal axis is rounded at a first corner having a first edge radius, a second side view of the second edge portion is rounded at a second corner having a second edge radius; An irreversible electroporation ablation device.

2. The first electrode has a first electrode surface area, the second electrode has a second electrode surface area, The irreversible electroporation ablation device according to claim 1, wherein a difference between the first electrode surface area and the second electrode surface area is less than 20% of the first electrode surface area.

3. The irreversible electroporation ablation device according to claim 2, wherein a difference between the first electrode surface area and the second electrode surface area is less than 10% of the first electrode surface area.

4. The irreversible electroporation ablation device according to any one of claims 1 to 3, wherein a distance between the first edge portion and the second edge portion is in a range of 1 millimeter to 2 millimeters.

5. The irreversible electroporation ablation device according to any one of claims 1 to 3, wherein a distance between the first edge portion and the second edge portion is in a range of 1.4 millimeters to 1.8 millimeters.

6. The irreversible electroporation ablation device according to any one of claims 1 to 3, wherein the second electrode pair is a sensing electrode configured to measure an electrical signal.

7. The irreversible electroporation ablation device according to any one of claims 1 to 3, wherein the electrode assembly further comprises a fifth ring electrode disposed further away from the distal end of the elongated body than each electrode of the first electrode pair. **Claim 8** The first electrode includes a conductive material having a first thickness, and the first edge radius is associated with the first thickness. The irreversible electroporation ablation device according to any one of claims 1 to 3, wherein the second electrode includes a conductive material having a second thickness, and the second edge radius is associated with the second thickness.

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