Systems and methods for energizing electroporation catheters using a tetrapolar array - Patents.com

Abstract

An apparatus is provided for controlling an electroporation catheter comprising a distal end, a proximal end, a plurality of splines extending from the distal end to the proximal end, and a plurality of electrodes disposed on the plurality of splines defining at least one quadripolar array, each of the quadripolar arrays being defined by four of the plurality of electrodes. The apparatus comprises a pulse generator coupled to the electroporation catheter and a computing device coupled to the pulse generator, the computing device operable to control the pulse generator to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a first energization pattern and to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a second energization pattern, the first energization pattern and the second energization pattern being different from one another.

Description

[Background technology]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to Provisional Application No. 63 / 278,605, filed November 12, 2021, which is incorporated herein by reference in its entirety. [Technical Field]

[0002] The present disclosure relates generally to tissue ablation systems. In particular, the present disclosure relates to applying electroporation therapy using a catheter including multiple electrodes defining at least one quadripolar array.

[0003] It is generally known that ablation therapy may be used to treat various conditions afflicting the human body. For example, ablation therapy may be used to treat atrial arrhythmia. Tissue is ablated, or at least damaged, when exposed to ablation energy generated by an ablation generator and delivered by an ablation catheter. Electrodes attached to or within the ablation catheter are used to induce tissue necrosis in cardiac tissue to ameliorate conditions such as atrial arrhythmias (including, but not limited to, ectopic atrial tachycardia, atrial fibrillation, atrial flutter, etc.).

[0004] Cardiac arrhythmias (i.e., irregular heart rhythms) can cause a variety of dangerous conditions, such as loss of atrioventricular synchronization and blood flow congestion, leading to various illnesses and even death. The primary cause of atrial arrhythmias is thought to be stray electrical signals within the left or right atrium of the heart. Ablation catheters deliver ablation energy (e.g., radiofrequency energy, cryoablation, laser, chemical agents, or high-intensity focused ultrasound) to cardiac tissue, creating lesions in the tissue. This lesion blocks unwanted electrical pathways, thereby limiting or preventing the stray electrical signals that lead to arrhythmias.

[0005] Electroporation is a non-thermal ablation technique that applies a strong electric field to induce pore formation in cell membranes. The electric field may be induced by applying relatively short pulses, e.g., nanoseconds to a few milliseconds. Such pulses may be repeated to form a pulse train. When such an electric field is applied to tissue in vivo, cells within the tissue experience a transmembrane potential, causing pores in the cell wall to open. Electroporation can be reversible (i.e., the temporarily opened pores reclose) or irreversible (i.e., the pores remain open). For example, in the field of gene therapy, reversible electroporation (i.e., temporary pore opening) is used to transfect cells with high-molecular-weight therapeutic vectors. In other therapeutic applications, appropriately configured pulse trains alone may be used to cause cell destruction, e.g., by inducing irreversible electroporation.

[0006] For example, pulsed field ablation (PFA) may be used to perform instantaneous pulmonary vein isolation (PVI). PFA generally involves delivering high-voltage pulses from electrodes placed on a catheter. For example, the voltage pulses may range from less than about 500 volts to about 2400 volts or more. These electric fields may be applied between a pair of electrodes (bipolar treatment) or between one or more electrodes and a return patch (unipolar treatment). Summary of the Invention [Means for solving the problem]

[0007] In one embodiment, an apparatus for controlling an electroporation catheter is provided. The electroporation catheter includes a distal end, a proximal end, a plurality of splines extending from the distal end to the proximal end, and a plurality of electrodes disposed on the plurality of splines and defining at least one quadripolar array, each quadripolar array being defined by four of the plurality of electrodes. The apparatus includes a pulse generator coupled to the electroporation catheter and a computing device coupled to the pulse generator, the computing device operable to control the pulse generator to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a first energization pattern and to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a second energization pattern, the first energization pattern and the second energization pattern being different from each other.

[0008] In another aspect, a method is provided for controlling a system including an electroporation catheter, a pulse generator coupled to the electroporation catheter, and a computing device coupled to the pulse generator. The electroporation catheter comprises a distal end, a proximal end, a plurality of splines extending from the distal end to the proximal end, and a plurality of electrodes disposed on the plurality of splines and defining at least one quadripolar array, each quadripolar array being defined by four of the plurality of electrodes. The method includes: using the computing device and the pulse generator to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a first energization pattern; and using the computing device and the pulse generator to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a second energization pattern, the first energization pattern and the second energization pattern being different from one another.

[0009] In yet another aspect, a system is provided, comprising: an electroporation catheter comprising: a distal end, a proximal end, a plurality of splines extending from the distal end to the proximal end; and a plurality of electrodes disposed on the plurality of splines and defining at least one quadripolar array, each quadripolar array being defined by four of the plurality of electrodes. The system further comprises: a pulse generator coupled to the electroporation catheter; and a computing device coupled to the pulse generator, the computing device operable to control the pulse generator to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a first energization pattern and to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a second energization pattern, the first energization pattern and the second energization pattern being different from one another.

[0010] The foregoing and other aspects, features, details, utilities, and advantages of the present disclosure will become apparent from a reading of the following description and claims, and from a reference to the accompanying drawings. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram and block diagram of a system for electroporation therapy.

[0012] [Figure 2] FIG. 2 is a side view of an embodiment of a grid assembly that can be used with the catheter shown in FIG. 1.

[0013] [Figure 3] 3 is an image showing the grid assembly of FIG. 2 positioned within a patient's heart.

[0014] [Figure 4A] An example of a current flow pattern using the grid assembly shown in FIG. 2 is shown below. [Figure 4B]An example of a current flow pattern using the grid assembly shown in FIG. 2 is shown below. [Figure 4C] An example of a current flow pattern using the grid assembly shown in FIG. 2 is shown below.

[0015] [Figure 5A] An example of a current flow pattern using the grid assembly shown in Figure 2 is shown below.

[0016] [Figure 5B] FIG. 5B is a diagram showing a simulation of the electric field intensity of the current conduction pattern shown in FIG. 5A.

[0017] [Figure 5C] FIG. 5B is a diagram showing a simulation of the potential field of the current conduction pattern shown in FIG. 5A.

[0018] [Figure 6] FIG. 4C is a diagram showing a simulation of the electric field intensity of a current conduction pattern corresponding to the current conduction pattern of FIG. 4B.

[0019] [Figure 7] FIG. 4D is a diagram showing a simulation of the electric field intensity of a current conduction pattern corresponding to the current conduction pattern of FIG. 4C.

[0020] [Figure 8A] This is a representation of the diagram shown in FIG. 5B. [Figure 8B] This is a representation of the diagram shown in Figure 6. [Figure 8C] This is a representation of the diagram shown in Figure 7.

[0021] [Figure 9] This is a diagram in which FIGS. 8A to 8C are superimposed.

[0022] [Figure 10A] An example of an additional current flow pattern using the grid assembly shown in FIG. 2 is shown below. [Figure 10B]An example of an additional current flow pattern using the grid assembly shown in FIG. 2 is shown below. [Figure 10C] An example of an additional current flow pattern using the grid assembly shown in FIG. 2 is shown below. [Figure 10D] An example of an additional current flow pattern using the grid assembly shown in FIG. 2 is shown below.

[0023] [Figure 11A] FIG. 2 is a perspective view of one embodiment of a basket assembly that can be used with the catheter shown in FIG. 1. [Figure 11B] FIG. 2 is a perspective view of one embodiment of a basket assembly that can be used with the catheter shown in FIG. 1.

[0024] [Figure 12A] 1. FIG. 3 is a diagram of another embodiment of a basket assembly that can be used with the catheter shown in FIG. [Figure 12B] 1. FIG. 3 is a diagram of another embodiment of a basket assembly that can be used with the catheter shown in FIG. [Figure 12C] 1. FIG. 3 is a diagram of another embodiment of a basket assembly that can be used with the catheter shown in FIG.

[0025] [Figure 13] FIG. 2 is a schematic diagram of one embodiment of a switching architecture that may be used in the system shown in FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0026] The systems and methods described herein are directed to an apparatus for controlling an electroporation catheter. The electroporation catheter includes a distal end, a proximal end, a plurality of splines extending from the distal end to the proximal end, and a plurality of electrodes disposed on the plurality of splines and defining at least one quadripolar array, each quadripolar array being defined by four of the plurality of electrodes. The apparatus includes a pulse generator coupled to the electroporation catheter and a computing device coupled to the pulse generator, the computing device operable to control the pulse generator to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a first energization pattern and to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a second energization pattern, the first energization pattern and the second energization pattern being different from each other.

[0027] FIG. 1 is a schematic and block diagram of a system 10 for electroporation therapy. Generally, the system 10 includes a catheter electrode assembly 12 disposed at the distal end 48 of a catheter 14. As used herein, "proximal" refers to the direction toward the end of the catheter closest to the clinician, and "distal" refers to the direction away from the clinician and (generally) within the patient's body. The electrode assembly includes one or more individual, electrically isolated electrode elements. Each electrode element, also referred to herein as a catheter electrode, is individually wired so that it can be selectively paired or combined with other electrode elements to function as a bipolar or multipolar electrode.

[0028] System 10 may be used for irreversible electroporation (IRE) to destroy tissue. In particular, system 10 may be used for electroporation therapy, which involves delivering electrical current in a manner that directly and irreversibly loses the integrity of the plasma membrane (cell wall), causing cell membrane disruption and cell necrosis. This mechanism of cell death may be considered an "outside-in" process, meaning that disruption of the cell's outer wall has a deleterious effect on the cell's interior. Typically, in standard cell membrane electroporation, electrical current is delivered as a pulsed electric field in the form of brief pulses (e.g., having a duration of 100 nanoseconds (ns) to 100 microseconds (μs)) between closely spaced but spaced electrodes, capable of delivering a field strength of approximately 0.1 to 10.0 kilovolts per centimeter (kV / cm). System 10 may be used with a grid catheter, such as that depicted in FIG. 2, for high-power (e.g., high voltage and / or high current) electroporation procedures. Alternatively, system 10 may be used with any suitable catheter configuration.

[0029] In one embodiment, all electrodes of the catheter carry current simultaneously. Alternatively, in other embodiments, stimulation is applied selectively (e.g., between pairs of electrodes) on the catheter. For example, in some embodiments, the catheter comprises multiple splines, each containing multiple electrodes. In such embodiments, electrodes on one spline may be selectively activated, while electrodes on adjacent (or other) splines may act as energy return (or sink). Furthermore, in the embodiments described herein, the electrodes may be switchable between being connected to a 3D mapping system and an electroporation generator.

[0030] Irreversible electroporation with a multielectrode catheter may enable pulmonary vein isolation with as few as one shock per vein, significantly shortening procedure time compared with sequential placement of radiofrequency (RF) ablation tips around the veins.

[0031] Although the energization method is described as including DC pulses, it should be understood that embodiments may use variations and remain within the spirit and scope of the present disclosure. For example, exponentially decaying pulses, exponentially increasing pulses, and combinations may be used.

[0032] Furthermore, it should be understood that the mechanism of cell destruction in electroporation is not primarily due to a heating effect, but rather to the disruption of cell membranes by the application of a high-voltage electric field. Thus, electroporation may avoid some of the thermal effects that can occur when using radiofrequency (RF) energy. This "cold therapy" has desirable characteristics.

[0033] With this background, and referring again now to FIGURE 1, system 10 includes a catheter electrode assembly 12 including at least one catheter electrode. Electrode assembly 12 is incorporated as part of a medical device, such as a catheter 14, for electroporation treatment of tissue 16 within a patient's body 17. In the exemplary embodiment, tissue 16 includes a heart or cardiac tissue. However, it should be understood that the embodiment may be used to perform electroporation treatment on a variety of other body tissues.

[0034] FIG. 1 further shows multiple return electrodes, designated 18, 20, and 21, illustrating body connections that may be used by various subsystems included in the overall system 10, such as an electroporation generator 26, an electrophysiology (EP) monitor such as an ECG monitor 28, and a localization and navigation system 30 for visualization, mapping, and navigation of internal body structures. In the illustrated embodiment, the return electrodes 18, 20, and 21 are patch electrodes. It should be understood that the illustration of a single patch electrode is merely schematic (for clarity) and that the subsystems to which these patch electrodes are connected may, and typically will, include more than one patch (body surface) electrode, and may include a split patch electrode (as described herein). In other embodiments, the return electrodes 18, 20, and 21 may be other types of electrodes suitable for use as return electrodes, including, for example, one or more catheter electrodes. A catheter return electrode may be part of the electrode assembly 12 or a separate catheter or device (not shown). System 10 may further include a main computer system 32 (including an electronic control unit 50 and a data storage memory 52), which may, in certain embodiments, be integrated with location and navigation system 30. System 32 may further include conventional interface components such as various user input / output mechanisms 34A and a display 34B, among other things.

[0035] The electroporation generator 26 is configured to energize the electrode elements according to an electroporation energization strategy, which may be predetermined or user-selectable. For primary necrotic treatment by electroporation, the generator 26 may be configured to generate current delivered through the electrode assembly 12 as a pulsed electric field in the form of short-duration DC pulses (e.g., nanoseconds to milliseconds in duration, or any duration suitable for electroporation) between closely spaced electrodes, capable of delivering a field strength (i.e., at the tissue site) of approximately 0.1 to 1.0 kV / cm. The amplitude and pulse duration required for irreversible electroporation are inversely related.

[0036] The electroporation generator 26, sometimes referred to herein as a DC energy source, is a biphasic electroporation generator 26 configured to generate a series of DC energy pulses that all generate current in two directions. In other embodiments, the electroporation generator is a monophasic or polyphasic electroporation generator. In some embodiments, the electroporation generator 26 is configured to output energy in DC pulses at selectable energy levels, such as 50 joules, 100 joules, or 200 joules. Other embodiments may have more or fewer energy settings, and the available settings may have the same or different values. For successful electroporation, some embodiments utilize a power level of 200 joules. For example, the electroporation generator 26 may output DC pulses having a peak magnitude of about 300 volts (V) to about 3,200 V at a power level of 200 joules. Other embodiments may output any other suitable positive or negative voltage.

[0037] In some embodiments, variable impedance 27 can vary the impedance of system 10 to limit arcing. Additionally, variable impedance 27 may be used to change one or more characteristics, such as the amplitude, duration, or pulse shape, of the output of electroporation generator 26. Although illustrated as a separate component, variable impedance 27 may be incorporated into catheter 14 or generator 26.

[0038] 1, as noted above, catheter 14 may include functionality for electroporation and, in certain embodiments, may also include ablation functionality (e.g., RF ablation). However, it should be understood that variations are possible in those embodiments with respect to the type of ablation energy provided (e.g., cryoablation, ultrasound, etc.).

[0039] In the illustrated embodiment, the catheter 14 includes a cable connector or interface 40, a handle 42, and a shaft 44 having a proximal end 46 and a distal end 48. The catheter 14 may also include other conventional components not shown herein, such as a temperature sensor, additional electrodes, and corresponding electrical conductors or leads. The connector 40 provides a mechanical and electrical connection for a cable 56 extending from the generator 26. The connector 40 may include conventional components known in the art and is located at the proximal end of the catheter 14, as shown.

[0040] The handle 42 provides a location for the clinician to hold the catheter 14 and may also provide a means for steering or guiding the shaft 44 within the body 17. For example, the handle 42 may include a means for changing the length of a guidewire extending through the catheter 14 to the distal end 48 of the shaft 44 or a means for steering the shaft 44. Additionally, in some embodiments, the handle 42 may be configured to change the shape, size, and / or orientation of a portion of the catheter, and it will be understood that the configuration of the handle 42 may vary. In alternative embodiments, the catheter 14 may be robotically driven or controlled. Thus, rather than a clinician manipulating the handle to advance / retreat and / or steer or guide the catheter 14 (and particularly its shaft 44), a robot is used to manipulate the catheter 14. The shaft 44 is an elongated, tubular, flexible member configured to move within the body 17. The shaft 44 is configured to support the electrode assembly 12 and contain associated conductors and, possibly, additional electronics used for signal processing or conditioning. Shaft 44 may also allow for the transport, delivery, and / or removal of fluids (including irrigation fluids and bodily fluids), medications, and / or surgical tools or instruments. Shaft 44 may be made from conventional materials, such as polyurethane, and defines one or more lumens configured to accommodate and / or transport electrical conductors, fluids, or surgical tools, as described herein. Shaft 44 may be introduced into a blood vessel or other structure within body 17 via a conventional introducer. Shaft 44 may then be advanced / retracted and / or steered or guided through body 17 to a desired location, such as a site at tissue 16, including by use of a guidewire or other means known in the art.

[0041] In some embodiments, the catheter 14 is a grid catheter having a catheter electrode (not shown in FIG. 1 ) disposed at the distal end of the shaft 44. In some embodiments, the catheter 14 has 16 catheter electrodes. In other embodiments, the catheter 14 includes 10 catheter electrodes, 20 catheter electrodes, or any other suitable number of electrodes for performing electroporation. In some embodiments, the catheter electrodes are ring electrodes, such as platinum ring electrodes. Alternatively, the catheter electrodes may be any other suitable type of electrode, such as partial ring electrodes or electrodes printed on a flexible material. In various embodiments, the catheter electrodes have lengths of 1.0 mm, 2.0 mm, 2.5 mm, and / or any other length suitable for electroporation.

[0042] A localization and navigation system 30 may be provided for visualizing, mapping, and navigating internal body structures. The localization and navigation system 30 may include conventional devices commonly known in the art. For example, the localization and navigation system 30 may be substantially similar to the EnSitePrecision™ system commercially available from Abbott Laboratories, Inc., as shown in commonly assigned U.S. Patent No. 7,263,397, entitled "Method and Apparatus for Catheter Navigation and Location and Mapping in the Heart," the disclosure of which is incorporated herein by reference in its entirety. In another example, the localization and navigation system 30 may be substantially similar to the EnSiteX™ system generally shown in U.S. Patent Application Publication No. 2020 / 0138334, entitled "Method for Medical Device Localization Based on Magnetic and Impedance Sensors," the disclosure of which is incorporated herein by reference in its entirety. However, it should be understood that the localization and navigation system 30 is illustrative only and not limiting in nature. Other techniques for locating / navigating (and visualizing) catheters in space are known, such as Biosense Webster's CARTO navigation and positioning system, Boston Scientific Scimed's Rhythmia® system, Koninklijke·Philips' KODEX® system, Northern Digital's AURORA® system, commercially available fluoroscopic systems, or magnetic positioning systems such as Mediguide's gMPS system.In this regard, some localization, navigation, and / or visualization systems may include sensors provided to generate signals indicative of catheter position information, which may include, for example, one or more electrodes in the case of an impedance-based localization system, or one or more coils (i.e., wire windings) configured to detect one or more characteristics of a magnetic field in the case of a magnetic field-based localization system. As yet another example, system 10 may utilize a combined electric field-based and magnetic field-based system, such as that generally described with reference to U.S. Patent No. 7,536,218, entitled "Hybrid Magnetic-Based and Impedance Based Position Sensing," which is incorporated herein by reference in its entirety.

[0043] In at least some of the embodiments described herein, the catheter includes an electrode array that defines one or more pixels. The electrode array may be disposed, for example, on a grid catheter (e.g., as shown in Figures 2-5B) or a basket catheter (e.g., as shown in Figures 6A-7C). Alternatively, the electrode array may be disposed on any suitable catheter assembly.

[0044] 2 is a side view of one embodiment of a grid assembly 200 that may be used with the catheter 14 in the system 10. Those skilled in the art will appreciate that in other embodiments, any suitable catheter may be used. Additionally, while the embodiments disclosed herein are discussed in the context of a grid catheter, those skilled in the art will appreciate that the methods and systems described herein may be practiced using any suitable catheter (e.g., a basket catheter, etc.). As shown in FIG. 2, the grid assembly 200 is coupled to a distal portion 202 of the shaft 44.

[0045] The grid assembly 200 includes a plurality of splines 204 extending from a proximal end 206 to a distal end 208. Each spline 204 includes a plurality of electrodes 210. In the embodiment shown in FIG. 2, the grid assembly 200 includes four splines 204, each including four electrodes 210, such that the electrodes 210 form a grid configuration. Thus, the grid assembly 200 provides a 4×4 grid of electrodes 210. In one embodiment, the spacing between each pair of adjacent electrodes 210 is approximately 4 millimeters (mm), such that the dimensions of the grid of electrodes 210 are approximately 12 mm×12 mm. Alternatively, the grid assembly 200 may have any suitable number of splines 204, any suitable number of electrodes 210, and / or any suitable arrangement of electrodes 210. For example, in some embodiments, the spacing between each pair of adjacent electrodes is approximately 2 millimeters (mm). Additionally, in some embodiments, the grid assembly 200 may include, for example, 56 electrodes arranged in a 7x8 grid.

[0046] The grid assembly 200 may be used to create lesions at individual electrodes 210 using a monopolar approach (e.g., by applying a voltage between an individual electrode 210 and a return patch) or to create lesions between pairs of electrodes 210 using a bipolar approach. Lesions may be created in the anatomical structure by selectively energizing the electrodes in a particular configuration and / or pattern (e.g., including energizing individual electrodes 210 independently of one another or energizing multiple electrodes 210 simultaneously).

[0047] 3 is an image 300 showing a grid assembly 200 positioned within the left atrium 302 of a patient's heart. As shown in FIG. 3, the grid assembly 200 covers a relatively large area of ​​the heart. The width of this area is generally larger than that required to perform pulmonary vein isolation (PVI). Therefore, it may be possible to energize only a portion of the grid assembly 200 to perform successful PVI ablation.

[0048] The bipolar supply pattern allows for multiple different energization patterns to be utilized using the grid assembly 200. For example, each electrode 210 may selectively function as a positive electrode, a negative electrode, or an inert electrode. If all electrodes 210 are energized with the same polarity, the indifferent electrode (e.g., one of surface electrodes 18, 20, or 21 (shown in FIG. 1)) functions as the return electrode. If some electrodes 210 are energized with positive polarity and other electrodes 210 are energized with negative polarity, an indifferent electrode is not required because there is a current path between the electrodes 210.

[0049] In the embodiments described herein, energy is uniformly delivered using a quadripolar array (i.e., a 2x2 array) of electrodes 210. In this embodiment, the grid assembly 200 includes four quadripolar arrays 220, as shown in Figure 2. As will be appreciated by those skilled in the art, several different energization schemes are possible for the quadripolar arrays 220 of electrodes 210. For example, in some embodiments, different quadripolar arrays 220 may share at least one electrode 210.

[0050] For example, FIGS. 4A, 4B, and 4C show a first energization pattern 402, a second energization pattern 404, and a third energization pattern 406, respectively.

[0051] In the first current conduction pattern 402, the first electrode 410 is positive, the second electrode 412 is negative, the third electrode 414 is negative, and the fourth electrode 416 is positive. In the second current conduction pattern 404, the first electrode 410 is positive, the second electrode 412 is positive, the third electrode 414 is negative, and the fourth electrode 416 is negative. In the third current conduction pattern 406, the first electrode 410 is positive, the second electrode 412 is negative, the third electrode 414 is positive, and the fourth electrode 416 is negative.

[0052] Those skilled in the art will appreciate that other current patterns are possible, particularly those that are redundant (i.e., the polarity of each electrode 210 is swapped), degenerate (i.e., all electrodes 210 have the same polarity), or unequal (i.e., have a different number of positive and negative electrodes 210) with respect to the current patterns shown in Figures 4A-4C.

[0053] 5A is an example energization pattern 502 for all 16 electrodes 210 of the catheter assembly 200. Specifically, the energization pattern 502 corresponds to each quadripolar array 220 using the first energization pattern 402 (shown in FIG. 4A).

[0054] 5B is a diagram 510 that simulates the electric field strength (e.g., in volts per centimeter (V / cm)) when energization pattern 502 is implemented. As shown in diagram 510, the electric field strength is highest around each electrode 210. Meanwhile, the electric field strength is low at low field spots 512. Low field spots 512 are generally located at the midpoints between adjacent electrodes 210 with the same polarity. Thus, energization pattern 502 generates low field spots 512 approximately in the center of each quadrupole array 220. At low field spots 512, the electric field gradient is zero or near zero, resulting in low field strength.

[0055] Figure 5C is a diagram 520 that simulates the potential field when current conduction pattern 502 is implemented. As shown in Figure 5C, saddle point 522 corresponds to the location of low electric field spot 512 in diagram 510. At saddle point 522, there is no tilt and therefore no gradient (i.e., corresponding to zero electric field strength).

[0056] Notably, different current conduction patterns generally result in different low field spots. For example, FIG. 6 is a diagram 600 that simulates the field strength of a current conduction pattern corresponding to the use of the second current conduction pattern 404 (shown in FIG. 4B) on each quadrupole array 220. Again, the field strength is highest around each electrode 210. However, in diagram 600, low field spots 602 occur between electrodes 210 located in the same row. Thus, low field spots 602 are located at different locations than low field spots 512 (shown in FIG. 5B). Furthermore, in diagram 600, the field strength is relatively high at locations corresponding to low field spots 512 in diagram 510.

[0057] As another example, Figure 7 is a diagram 700 that simulates the electric field strength of a current conduction pattern corresponding to the use of third current conduction pattern 406 (shown in Figure 4C) on each quadrupole array 220. In diagram 700, low field spots 702 are generated between electrodes 210 located in the same column. Again, low field spots 702 are located at different positions than low field spots 512 (shown in Figure 5B) and low field spots 602 (shown in Figure 6). Furthermore, in diagram 700, the electric field strength is relatively high at locations corresponding to low field spots 512 in diagram 510 and low field spots 602 in diagram 600.

[0058] Therefore, by applying a combination of current patterns, a relatively uniform field strength can be achieved (as low field spots in certain current patterns are compensated for by other current patterns). In this way, cycling through multiple current patterns results in a relatively uniform overall ablation region.

[0059] For example, Figure 8A is a representation 802 of diagram 510 (shown in Figure 5B), Figure 8B is a representation 804 of diagram 600 (shown in Figure 6), and Figure 8C is a representation 806 of diagram 700 (shown in Figure 7). Figure 9 is a diagram 900 showing representations 802, 804, and 806 superimposed on one another. As shown by diagram 900, when representations 802, 804, and 806 are superimposed on one another (corresponding to cycling through all three energization patterns), the ablation region produced is relatively uniform, with holes in one energization pattern being filled in by the other energization patterns.

[0060] Those skilled in the art will appreciate that other energization patterns (i.e., other than those shown in Figures 4A-4C) may be used for each tetrapolar array 220. For example, Figures 10A-10D show a fourth energization pattern 1002, a fifth energization pattern 1004, a sixth energization pattern 1006, and a seventh energization pattern 1008. These energization patterns 1002, 1004, 1006, and 1008 are not balanced (i.e., have an unequal number of positive and negative electrodes).

[0061] In a fourth current conduction pattern 1002, the first electrode 1010 is negative, the second electrode 1012 is negative, the third electrode 1014 is negative, and the fourth electrode 1016 is positive. In a fifth current conduction pattern 1004, the first electrode 1010 is negative, the second electrode 1012 is negative, the third electrode 1014 is positive, and the fourth electrode 1016 is negative. In a sixth current conduction pattern 1006, the first electrode 1010 is negative, the second electrode 1012 is positive, the third electrode 1014 is negative, and the fourth electrode 1016 is negative. In a seventh current conduction pattern 1008, the first electrode 1010 is negative, the second electrode 1012 is positive, the third electrode 1014 is positive, and the fourth electrode 1016 is positive.

[0062] Although the embodiments described herein are discussed in the context of IRE / PFA, those skilled in the art will understand that the methods and systems described herein may also be utilized in RF ablation applications.

[0063] Additionally, those skilled in the art will appreciate that the techniques described herein may be implemented in catheter configurations other than grid assembly 200. For example, FIGS. 11A and 11B are perspective views of one embodiment of a basket assembly 1100 including a plurality of splines 1102 forming a basket, each spline including a plurality of electrodes 1104. Similar to grid assembly 200, a quadripolar array can be defined by the set of electrodes 1104. For example, first electrode 1110, second electrode 1112, third electrode 1114, and fourth electrode 1116 define quadripolar array 1120 (shown in FIG. 11B). Other catheter configurations may utilize similar implementations.

[0064] 12A-12C are diagrams of another embodiment of a basket assembly 1250 that may be used with the electrode energization techniques described herein. Specifically, FIG. 12A is a perspective view of the basket assembly 1250, and FIGS. 12B and 12C are side views of the basket assembly 1250 positioned within a pulmonary vein 1252.

[0065] The basket assembly 1250 includes a plurality of splines 1254 that form the basket. In this embodiment, each spline 1254 has a generally sigmoidal shape. The sigmoidal shape of the splines 1254 causes adjacent splines 1254 to maintain approximately the same distance from each other along the length of the splines 1254, which may improve injury quality. In this embodiment, the basket assembly 1250 includes eight splines 1254. Alternatively, the basket assembly 1250 may include any suitable number of splines 1254.

[0066] 12A, basket assembly 1250 may include a selectively inflatable balloon 1256 positioned inside the basket. Balloon 1256 may facilitate support of splines 1254 (e.g., when the splines are pressed against tissue). In some embodiments, balloon 1256 is omitted. Further details regarding basket assemblies having sigmoidal splines can be found in International Application No. PCT / US20 / 36410, filed June 5, 2020, entitled "ELECTRODE BASKET HAVING HIGH-DENSITY CIRCUMFERENTIAL BAND OF ELECTRODES," and U.S. Provisional Patent Application No. 62 / 861,135, filed June 13, 2019, entitled "ELECTRODE BASKET HAVING HIGH-DENSITY CIRCUMFERENTIAL BAND OF ELECTRODES," the disclosures of which are incorporated herein by reference in their entireties.

[0067] Each spline 1254 includes at least one electrode 1270 that can be selectively energized using the systems and methods disclosed herein. For example, FIG. 7B shows one elongated electrode 1272 on each spline 1254, while FIG. 7C shows multiple individual electrodes 1274 on each spline 1254. The electrodes 1270 are generally positioned at a distal portion of the basket assembly 1250 to facilitate contact with tissue in the pulmonary vein 1252. Alternatively, any suitable configuration of electrodes 1270 may be used. As with previously described embodiments, the set of individual electrodes 1274 on the basket assembly 1250 may define a quadripolar array, and energization schemes similar to those described above may be suitably implemented.

[0068] As described herein, electrodes on a catheter are selectively energized to generate different patterns. Figure 13 is a schematic diagram of one embodiment of a switching architecture 1300 that may be used to selectively energize electrodes on a catheter 1302. Specifically, the switching architecture includes the catheter 1302, a pulse source 1304, and a switching unit 1306 coupled between the catheter 1302 and the pulse source 1304.

[0069] The pulse source 1304 generates energy pulses that are applied by electrodes (not shown) on the catheter 1302. Additionally, the switching unit 1306 includes a plurality of switching circuits 1310 for selectively delivering energy pulses from the pulse source 1304 to the electrodes. In this embodiment, the switching unit 1306 includes a switching circuit 1310 (and corresponding channel) for each electrode. Each switching circuit 1310 receives energy pulses from the pulse source 1304 and delivers a positive pulse, a negative pulse, or no pulse to the corresponding electrode depending on the configuration of the switches in the switching circuit 1310. Thus, by controlling the switching circuits 1310, the electrodes on the catheter 1302 can be selectively energized.

[0070]

[0003] Embodiments described herein are directed to an apparatus for controlling an electroporation catheter comprising: a distal end, a proximal end, a plurality of splines extending from the distal end to the proximal end; and a plurality of electrodes disposed on the plurality of splines and defining at least one quadripolar array, each quadripolar array being defined by four of the plurality of electrodes. The apparatus comprises a pulse generator coupled to the electroporation catheter; and a computing device coupled to the pulse generator, the computing device operable to control the pulse generator to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a first energization pattern and to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a second energization pattern, the first energization pattern and the second energization pattern being different from one another.

[0071] While specific embodiments of the present disclosure have been described in some detail above, those skilled in the art may make numerous modifications to the disclosed embodiments without departing from the spirit or scope of the present disclosure. All directional references (e.g., up, down, upward, downward, left, right, leftward, rightward, up, down, upward, downward, vertical, horizontal, clockwise, and counterclockwise) are used solely for identification purposes to aid the reader's understanding of the present disclosure and are not intended to impose any limitations on the location, orientation, or use of the present disclosure. Joined references (e.g., attached, coupled, connected, etc.) should be interpreted broadly and may include intermediate members between connections of elements and relative movement between elements. As such, joined references do not necessarily infer that two elements are directly connected and in a fixed relationship to each other. All matter contained in the above description or shown in the accompanying drawings is intended to be illustrative only and not limiting. Changes in detail or structure may be made without departing from the spirit of the present disclosure, as defined by the appended claims.

[0072] When introducing elements of the disclosure or preferred embodiments thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0073] Since various changes may be made in the above configurations without departing from the scope of the present disclosure, it is intended that all matter contained in the above description or shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. The following items are the contents of the claims at the time of international application. (Item 1) 1. An apparatus for controlling an electroporation catheter, comprising: The electroporation catheter comprises: a distal end; and a proximal end; a plurality of splines extending from the distal end to the proximal end; a plurality of electrodes disposed on the plurality of splines and defining at least one quadripolar array, each quadripolar array being defined by four electrodes of the plurality of electrodes; Equipped with The device comprises: a pulse generator coupled to the electroporation catheter; a computing device coupled to the pulse generator; Equipped with the computing device is operable to control the pulse generator to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a first energization pattern and to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a second energization pattern; The first current flow pattern and the second current flow pattern are different from each other. (Item 2) 2. The device of claim 1, wherein in the first current conduction pattern and the second current conduction pattern, each of the tetrapolar arrays includes two positive electrodes and two negative electrodes. (Item 3) 2. The device of claim 1, wherein in the first current conduction pattern and the second current conduction pattern, each of the tetrapolar arrays includes a different number of positive electrodes and negative electrodes. (Item 4) the computing device is further operable to control the pulse generator to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a third energization pattern; Item 10. The device of item 1, wherein the third current conduction pattern is different from the first current conduction pattern and the second current conduction pattern. (Item 5) energizing the plurality of electrodes according to the first energization pattern generates a first low electric field spot; energizing the plurality of electrodes according to the second energization pattern generates second low electric field spots; Item 10. The apparatus of item 1, wherein the first low electric field spot and the second low electric field spot are at different positions. (Item 6) the electroporation catheter includes a grid assembly formed by the plurality of splines and the plurality of electrodes; Item 10. The apparatus of item 1, wherein the computing device is operable to control the pulse generator to selectively energize the plurality of electrodes on the grid assembly. (Item 7) the electroporation catheter comprises a basket assembly formed by the plurality of splines and the plurality of electrodes; 2. The apparatus of claim 1, wherein the computing device is operable to control the pulse generator to selectively energize the plurality of electrodes on the basket assembly. (Item 8) 2. The apparatus of claim 1, wherein the computing device is operable to control the pulse generator to selectively energize the plurality of electrodes to provide bipolar therapy. (Item 9) 1. A method for controlling a system including an electroporation catheter, a pulse generator coupled to the electroporation catheter, and a computing device coupled to the pulse generator, comprising: The electroporation catheter comprises: a distal end; and a proximal end; a plurality of splines extending from the distal end to the proximal end; a plurality of electrodes disposed on the plurality of splines and defining at least one quadripolar array, each quadripolar array being defined by four electrodes of the plurality of electrodes; Equipped with The method comprises: selectively energizing the plurality of electrodes defining the at least one tetrapolar array according to a first energization pattern using the computing device and the pulse generator; selectively energizing the plurality of electrodes defining the at least one tetrapolar array according to a second energization pattern using the computing device and the pulse generator; Including, The first energization pattern and the second energization pattern are different from each other. (Item 10) 10. The method of claim 9, wherein in the first current conduction pattern and the second current conduction pattern, each of the tetrapolar arrays includes two positive electrodes and two negative electrodes. (Item 11) 10. The method of claim 9, wherein in the first current conduction pattern and the second current conduction pattern, each of the tetrapolar arrays includes a different number of positive electrodes and negative electrodes. (Item 12) using the computing device and the pulse generator to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a third energization pattern; 10. The method according to claim 9, wherein the third energization pattern is different from the first energization pattern and the second energization pattern. (Item 13) energizing the plurality of electrodes according to the first energization pattern generates a first low electric field spot; energizing the plurality of electrodes according to the second energization pattern generates second low electric field spots; Item 10. The method of item 9, wherein the first low electric field spot and the second low electric field spot are at different positions. (Item 14) 10. The method of claim 9, wherein the electroporation catheter comprises a grid assembly formed by the plurality of splines and the plurality of electrodes. (Item 15) the electroporation catheter comprises a basket assembly formed by the plurality of splines and the plurality of electrodes; 10. The method of claim 9, wherein the computing device is operable to control the pulse generator to selectively energize the plurality of electrodes on the basket assembly. (Item 16) The system is 1. An electroporation catheter, comprising: a distal end; and a proximal end; a plurality of splines extending from the distal end to the proximal end; a plurality of electrodes disposed on the plurality of splines and defining at least one quadripolar array, each quadripolar array being defined by four of the plurality of electrodes; the electroporation catheter, a pulse generator coupled to the electroporation catheter; a computing device coupled to the pulse generator; Equipped with the computing device is operable to control the pulse generator to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a first energization pattern and to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a second energization pattern; The first energization pattern and the second energization pattern are different from each other. (Item 17) Item 17. The system of item 16, wherein in the first current conduction pattern and the second current conduction pattern, each of the tetrapolar arrays includes two positive electrodes and two negative electrodes. (Item 18) 17. The system of claim 16, wherein in the first current conduction pattern and the second current conduction pattern, each of the tetrapolar arrays includes a different number of positive electrodes and negative electrodes. (Item 19) the computing device is further operable to control the pulse generator to selectively energize the plurality of electrodes defining the at least one quadripolar array according to a third energization pattern; Item 17. The system of item 16, wherein the third energization pattern is different from the first energization pattern and the second energization pattern. (Item 20) energizing the plurality of electrodes according to the first energization pattern generates a first low electric field spot; energizing the plurality of electrodes according to the second energization pattern generates second low electric field spots; Item 17. The system of item 16, wherein the first low electric field spot and the second low electric field spot are at different locations.

Claims

1. 1. An apparatus for controlling an electroporation catheter, comprising: The electroporation catheter comprises: a distal end; and a proximal end; a plurality of splines extending from the distal end to the proximal end; a plurality of electrodes disposed on the plurality of splines, the plurality of electrodes including four electrodes defining a tetrapolar array arranged in a 2x2 array; Equipped with The device comprises: a pulse generator coupled to the electroporation catheter; a computing device coupled to the pulse generator; Equipped with the computing device is operative to control the pulse generator to energize the four electrodes according to a first energization pattern, such that some of the four electrodes function as positive electrodes and some of the four electrodes function as negative electrodes to generate a first low electric field spot, and then to energize the four electrodes according to a second energization pattern, such that some of the four electrodes function as positive electrodes and some of the four electrodes function as negative electrodes to generate a second low electric field spot; the first current conduction pattern and the second current conduction pattern are different from each other, The apparatus, wherein the first low electric field spot and the second low electric field spot are at different locations.

2. The device of claim 1 , wherein in the first current-carrying pattern and the second current-carrying pattern, the four electrodes include two positive electrodes and two negative electrodes.

3. The device of claim 1 , wherein the four electrodes include different numbers of positive and negative electrodes in the first and second current conduction patterns.

4. the computing device is further operative to control the pulse generator to energize the four electrodes in accordance with a third energization pattern, such that some of the four electrodes function as positive electrodes and other of the four electrodes function as negative electrodes to generate a third low electric field spot; the third current conduction pattern is different from the first current conduction pattern and the second current conduction pattern, The apparatus of claim 1 , wherein the third low field spot is at a different location than the first low field spot and the second low field spot.

5. the electroporation catheter includes a grid assembly formed by the plurality of splines and the plurality of electrodes; 10. The apparatus of claim 1, wherein the computing device is operable to control the pulse generator to energize the plurality of electrodes on the grid assembly such that some of the electrodes function as positive electrodes and other of the plurality of electrodes function as negative electrodes.

6. the electroporation catheter comprises a basket assembly formed by the plurality of splines and the plurality of electrodes; 2. The apparatus of claim 1, wherein the computing device is operable to control the pulse generator to energize the plurality of electrodes on the basket assembly such that some of the electrodes function as positive electrodes and other of the plurality of electrodes function as negative electrodes.

7. 10. The apparatus of claim 1, wherein the computing device is operable to control the pulse generator to energize the plurality of electrodes such that some of the electrodes function as positive electrodes and other of the plurality of electrodes function as negative electrodes to provide bipolar therapy.

8. 1. A method for controlling a system including an electroporation catheter, a pulse generator coupled to the electroporation catheter, and a computing device coupled to the pulse generator, comprising: The electroporation catheter comprises: a distal end; and a proximal end; a plurality of splines extending from the distal end to the proximal end; a plurality of electrodes disposed on the plurality of splines, the plurality of electrodes including four electrodes defining a tetrapolar array arranged in a 2x2 array; Equipped with The method comprises: the computing device and the pulse generator energizing the four electrodes according to a first energization pattern such that some of the four electrodes function as positive electrodes and other of the four electrodes function as negative electrodes to generate a first low electric field spot; After generating the first low electric field spot, the computing device and the pulse generator energize the four electrodes in accordance with a second energization pattern, such that some of the four electrodes function as positive electrodes and other of the four electrodes function as negative electrodes, to generate a second low electric field spot; Including, the first current conduction pattern and the second current conduction pattern are different from each other, The method, wherein the first low electric field spot and the second low electric field spot are at different locations.

9. The method of claim 8 , wherein in the first current-carrying pattern and the second current-carrying pattern, the four electrodes include two positive electrodes and two negative electrodes.

10. The method of claim 8 , wherein the four electrodes include different numbers of positive electrodes and negative electrodes in the first current-carrying pattern and the second current-carrying pattern.

11. the computing device and the pulse generator energizing the four electrodes according to a third energization pattern such that some of the four electrodes function as positive electrodes and other of the four electrodes function as negative electrodes to generate a third low electric field spot; the third current conduction pattern is different from the first current conduction pattern and the second current conduction pattern, The method of claim 8 , wherein the third low field spot is at a different location than the first low field spot and the second low field spot.

12. The method of claim 8 , wherein the electroporation catheter comprises a grid assembly formed by the plurality of splines and the plurality of electrodes.

13. the electroporation catheter comprises a basket assembly formed by the plurality of splines and the plurality of electrodes; 9. The method of claim 8, wherein the computing device is operable to control the pulse generator to energize the plurality of electrodes on the basket assembly such that some of the plurality of electrodes function as positive electrodes and other some of the plurality of electrodes function as negative electrodes.

14. An electroporation catheter, comprising: a distal end; and a proximal end; a plurality of splines extending from the distal end to the proximal end; a plurality of electrodes disposed on the plurality of splines, the plurality of electrodes including four electrodes defining a tetrapolar array arranged in a 2x2 array; the electroporation catheter, a pulse generator coupled to the electroporation catheter; a computing device coupled to the pulse generator; Equipped with the computing device is operative to control the pulse generator to energize the four electrodes according to a first energization pattern, such that some of the four electrodes function as positive electrodes and some of the four electrodes function as negative electrodes to generate a first low electric field spot, and then to energize the four electrodes according to a second energization pattern, such that some of the four electrodes function as positive electrodes and some of the four electrodes function as negative electrodes to generate a second low electric field spot; the first current conduction pattern and the second current conduction pattern are different from each other, The system, wherein the first low electric field spot and the second low electric field spot are at different locations from each other.

15. 15. The system of claim 14, wherein in the first current conduction pattern and the second current conduction pattern, the four electrodes include two positive electrodes and two negative electrodes.

16. 15. The system of claim 14, wherein the four electrodes include different numbers of positive and negative electrodes in the first and second current conduction patterns.

17. the computing device is further operative to control the pulse generator to energize the four electrodes in accordance with a third energization pattern, such that some of the four electrodes function as positive electrodes and other of the four electrodes function as negative electrodes to generate a third low electric field spot; the third current conduction pattern is different from the first current conduction pattern and the second current conduction pattern, The system of claim 14 , wherein the third low field spot is at a different location than the first low field spot and the second low field spot.

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