Systems and methods for catheters with combined mapping and ablation capabilities

Abstract

A catheter assembly is provided that includes a tip electrode array including at least one tip electrode and located at a distal end of the catheter assembly, and a mini-electrode array including a plurality of mini-electrodes and located proximal to the tip electrode array, wherein each of the at least one tip electrode and each of the plurality of mini-electrodes are configured to be activated independently of one another for mapping applications, and at least some of the at least one tip electrode and the plurality of mini-electrodes are configured to be activated together for ablation applications.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 63 / 426,533, filed November 18, 2022, and U.S. Provisional Patent Application No. 63 / 533,003, filed August 16, 2023, both of which are incorporated by reference in their entireties.

[0002] (Disclosure Areas) The present disclosure relates generally to tissue ablation systems, and more particularly to catheters usable for both mapping and ablation applications. [Background technology]

[0003] It is generally known that ablation therapy is used to treat various conditions afflicting the human anatomy. For example, ablation therapy can be used to treat atrial arrhythmias. When tissue is ablated, or at least exposed to ablation energy generated by an ablation generator and delivered by an ablation catheter, lesions are formed in the tissue. Electrodes attached to or inserted into the ablation catheter are used to induce cell death in cardiac tissue (e.g., tissue apoptosis or necrosis) 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 create a variety of dangerous conditions, including loss of synchronized atrioventricular contractions and stasis of blood flow, 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 a scar in the tissue. This scar disrupts undesirable electrical pathways, thereby limiting or preventing the stray electrical signals that lead to arrhythmias.

[0005] Electroporation is a non-thermal ablation technique that involves applying a strong electric field to induce pore formation in cell membranes. The electric field can be induced by applying relatively short-duration pulses, e.g., from one nanosecond to several 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 introduce high-molecular-weight therapeutic vectors into cells. In other therapeutic applications, cell destruction can be induced using only appropriately configured pulse trains, e.g., by inducing irreversible electroporation.

[0006] Catheter-based cardiac mapping and catheter-based ablation are established diagnostic and therapeutic strategies for various cardiac arrhythmias. Many electrophysiology procedures are performed using minimally invasive surgical methods, in which one or more instruments are inserted into the patient's body through one or more small incisions. Instruments can have fixed or variable profiles (e.g., variable-diameter loops). Mapping or imaging systems typically calculate metrics from EGM signals and provide a visual display of the EGM measurements (color gradient) on the endocardial surface.

[0007] With respect to ablation, the instrument may also include a rigid or flexible component having an ablation device at or near its distal end that is generally placed adjacent to the tissue to be ablated. Pulsed fields, radio frequency, microwave energy, laser energy, extreme heat, or extreme cold may be delivered by the ablation device to necrose the tissue. Catheter-based devices have become valuable in a variety of medical and surgical applications because they are minimally invasive and allow for precise treatment of localized, individual tissues that are otherwise inaccessible.

[0008] Catheter-based imaging (i.e., mapping) systems are well known in the field of cardiac electrophysiology. Omnipolar mapping technology (OT) has enabled reliable processing of information underlying cardiac rhythm. Specifically, OT is a signal processing approach that more fully utilizes electrical signals from cardiac electrophysiology (EP) catheters. OT uses software algorithms that recognize the directional properties of intracardiac EGMs separated by multi-electrode catheters and characterize cardiac electrical activity in a manner that is unaffected by the orientation of the catheter wavefront. The resulting information is displayed in a manner that conforms to anatomical and physiological directions rather than a strict direction as seen from the catheter.

[0009] Radiofrequency (RF)-based ablation systems are known in the field of cardiac electrophysiology. In RF ablation procedures, a specially designed probe is typically placed directly at the target site in the patient. After a diagnostic EP study, a physician inserts an ablation catheter specifically designed to deliver radiofrequency energy to specific regions of interest within the patient's heart. Most ablation catheters are quadripolar, with an enlarged distal tip that contains the mechanisms for delivering radiofrequency energy to the heart. The radiofrequency energy is delivered as an alternating current, typically in the 350-750 kilohertz (kHz) frequency range, which accelerates electrons within cardiac cells, generating heat and destroying them within a defined area of ​​the catheter tip.

[0010] Like diagnostic catheters, there are many types of ablation catheters. These different types of catheters are designed to assist physicians in ablating different areas in patients of various sizes. Physicians typically select their preferred ablation catheter. However, in difficult cases, physicians may switch to a different type of catheter. Ablation catheters deliver energy to the heart to destroy cells that may be causing the patient's arrhythmia. This is typically done using an RF generator. Energy from the generator is transmitted through a connecting cable to the ablation catheter and focused on a specific area within the patient's heart. The goal is to create a small, inconspicuous scar at the selected site. Once the scar is formed, it is hoped that the transmission of electrical signals through that area will be blocked, halting the arrhythmia.

[0011] Once the ablation system is set up, a choice must be made between temperature control and power control. Typically, the physician uses the temperature control, where the desired temperature is selected and programmed into the generator. Also, the maximum power and duration of each ablation attempt, also known as a "burn," are selected. Once all of these parameters are entered, the ablation process is ready to begin.

[0012] Once the ablation catheter is activated, continuous readings of power, temperature, impedance, and time are displayed. The physician must be continuously informed of the above-mentioned value indicators. If any significant changes occur in any of the parameters, the technician must immediately inform the physician. In this way, any adverse effects during the ablation procedure can be avoided. Ablation procedures offer many advantages over open surgery. Patients often cannot be treated with traditional surgical procedures. Furthermore, if a patient has to undergo a second or more surgical procedures, it can be debilitating. Ablation can be performed multiple times on different occasions without the risks associated with surgical procedures.

[0013] One type of ablation procedure, a new technology with potential advantages, is known as pulsed-field ablation (PFA). While direct current (DC) shock therapy was initially abandoned due to safety concerns, it is now known in the art that DC shock can result in irreversible electroporation (IRE). The mechanism of scar formation in IRE is a function of electric field exposure, which disrupts cell membrane permeability and leads to cell death. Pulsed-field ablation (PFA) is a form of IRE that uses (most commonly) bipolar, biphasic high-voltage, ultrashort pulse trains, resulting in cell membrane destabilization (cell membrane pore formation) and cell death via an irreversible electroporation mechanism. This method offers several potential advantages for ablation of arrhythmias, including high selectivity for myocardial tissue and minimal thermal impact, thereby reducing the risk of inadvertent injury to blood vessels, nerves, or the esophagus.

[0014] In the field of cardiac electrophysiology, it is known that PFA can produce a durable transmembrane atrial lesion while minimizing impact on the esophagus, respiratory nerves, and coronary arteries. Consequently, interest in PFA as an alternative to RF ablation, particularly in the treatment of atrial fibrillation, has grown. Of the known PFA ablation catheter designs, the majority are stand-alone ablation catheters without mapping capabilities or integration with electroanatomical mapping systems.

[0015] While different ablation methods have their advantages, there may be situations in which one method is preferable over another. Furthermore, conditions can change rapidly during an ablation procedure, necessitating the rapid exchange of an ablation catheter for a mapping catheter or another type of ablation catheter, or vice versa. Currently, no system exists that evaluates electrical potential signals independently of catheter orientation, selects ablation techniques based on the patient's current condition, and provides medical technicians with the freedom to perform sequential or simultaneous ablation procedures without the difficult and time-consuming task of constantly exchanging one type of catheter for another.

[0016] Therefore, given the need for reduced procedure time and the need for precision during ablation procedures, it would be desirable to provide an ablation system that allows independence of catheter orientation, wave speed measurement and propagation direction, RF energy, cryoablation, and PFA. For example, cryoablation and RF ablation may be performed after real-time assessment of specific target tissue regions. Alternatively, cryoablation may be performed followed by PFA. It would also be desirable to provide an integrated ablation system that allows for accurate understanding of the underlying mechanisms, especially when operating on difficult-to-access sites such as the atrioventricular node (AN node).

[0017] Some electrophysiology experts advocate the use of multimodality techniques as a way to overcome the shortcomings of individual treatments. Eliminating one diagnostic catheter and performing treatment without the need to guess where to place an ablation catheter could result in a highly flexible, safe, and efficient tool that could significantly improve physician workflow and reduce the time required to treat patients. Summary of the Invention [Problem to be solved by the invention]

[0018] In one aspect, a catheter assembly is provided that includes a tip electrode array including at least one tip electrode and located at a distal end of the catheter assembly, and a mini-electrode array including a plurality of mini-electrodes and located proximal to the tip electrode array, wherein each of the at least one tip electrode and each of the plurality of mini-electrodes are configured to be activated independently of one another for mapping applications, and at least some of the at least one tip electrode and the plurality of mini-electrodes are configured to be activated together for ablation applications.

[0019] In another aspect, an electroporation system is provided that includes a generator and a catheter coupled to the generator, the catheter including a handle, a shaft extending distally from the handle, and a catheter assembly coupled to a distal end of the shaft, the catheter assembly including a tip electrode array having at least one tip electrode located at a distal end of the catheter assembly, and a mini-electrode array having a plurality of mini-electrodes located proximal to the tip electrode array, wherein each of the at least one tip electrode and each of the plurality of mini-electrodes are configured to be activated independently of one another for mapping applications, and at least some of the at least one tip electrode and the plurality of mini-electrodes are configured to be activated together for ablation applications.

[0020] In yet another aspect, an ablation system is provided that includes a console, at least one catheter, a cable system coupling the console to the at least one catheter, a hub coupled between the console and the at least one catheter, a first generator coupled to the hub and configured to deliver a first type of ablation energy to the at least one catheter through the hub, and a second generator coupled to the hub and configured to deliver a second type of ablation energy to the at least one catheter through the hub, wherein the console is configured to selectively control delivery of the first type of ablation energy and the second type of ablation energy to the at least one catheter through the hub.

[0021] These and other aspects, features, details, utilities, and advantages of the present disclosure will become apparent from reading the following description and claims, and from studying the accompanying drawings. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic block diagram of a system for electroporation therapy.

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

[0024] [Figure 3A] 3A is a perspective view of an alternative embodiment of a catheter assembly that may be used with the system shown in FIG.

[0025] [Figure 3B] 3B is a perspective view of an alternative embodiment of a catheter assembly that may be used with the system shown in FIG.

[0026] [Figure 3C] 3C is a perspective view of an alternative embodiment of a catheter assembly that may be used with the system shown in FIG.

[0027] [Figure 3D] 3D is a perspective view of an alternative embodiment of a catheter assembly that may be used with the system shown in FIG.

[0028] [Figure 3E] 3E is a perspective view of an alternative embodiment of a catheter assembly that may be used with the system shown in FIG.

[0029] [Figure 4A] FIG. 4A is a perspective view of an alternative embodiment of a tip electrode array that may be used with the system shown in FIG.

[0030] [Figure 4B] FIG. 4B is an exploded view of the tip electrode array shown in FIG. 4A.

[0031] [Figure 5] FIG. 5 is a perspective view of an alternative embodiment of a catheter assembly that may be used with the system shown in FIG.

[0032] [Figure 6A] FIG. 6A is a schematic diagram of one embodiment of a flex circuit architecture that may be used to implement the catheter assemblies described herein.

[0033] [Figure 6B] FIG. 6B is a schematic diagram of another embodiment of a flex circuit architecture that can be used to implement the catheter assemblies described herein.

[0034] [Figure 7] FIG. 7 is a schematic diagram of an alternative embodiment of a catheter assembly that may be used with the system shown in FIG.

[0035] [Figure 8] 8A and 8B are schematic diagrams of one embodiment of a mapping and ablation system.

[0036] [Figure 9] FIG. 9 is a schematic diagram of one embodiment of a catheter assembly that can be used with the system shown in FIGS. 8A and 8B.

[0037] [Figure 10A] FIG. 10A is a perspective view of an alternative embodiment of a catheter assembly that may be used with the system shown in FIGS. 8A and 8B.

[0038] [Figure 10B] FIG. 10B is an end view of the catheter assembly shown in FIG. 10A.

[0039] [Figure 7]FIG. 7 is a schematic diagram of an alternative embodiment of a catheter assembly that may be used with the system shown in FIG.

[0040] [Figure 11A] FIG. 11A is a side view of an alternative embodiment of a catheter assembly that may be used with the system shown in FIG.

[0041] [Figure 11B] FIG. 11B is a perspective view of the tip electrode array of the catheter assembly shown in FIG. 11A.

[0042] [Figure 12] 12A and 12B are perspective views of an alternative embodiment of a catheter assembly that may be used with the system shown in FIG.

[0043] [Figure 13] FIG. 13 is a perspective view of an alternative embodiment of a catheter assembly that may be used with the system shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0044] A catheter assembly system and method is provided that includes a tip electrode array including at least one tip electrode and located at a distal end of the catheter assembly, and a mini-electrode array including a plurality of mini-electrodes and located proximal to the tip electrode array, wherein each of the at least one tip electrode and each of the plurality of mini-electrodes are configured to be activated independently of one another for mapping applications, and at least some of the at least one tip electrode and the plurality of mini-electrodes are configured to be activated together for ablation applications.

[0045] Although at least some embodiments of the present disclosure are described with respect to pulmonary vein isolation (PVI), it is contemplated that the described features and methods of the present disclosure described herein may be incorporated into any number of systems and any number of applications, as would be understood by one of ordinary skill in the art based on the disclosure herein.

[0046] FIG. 1 is a 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 (generally) into the patient's body, away from the clinician. 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 to be selectively paired or combined with other electrode elements to function as a bipolar or multipolar electrode.

[0047] System 10 may be used for irreversible electroporation (IRE) to destroy tissue. In particular, system 10 may be used for electroporation-induced primary apoptosis therapy, which refers to the application of electrical current in a manner that directly causes irreversible loss of cell membrane (cell wall) integrity, leading to its destruction and cellular apoptosis. This cell death mechanism can be considered an "outside-in" process, meaning that destruction of the cell's outer wall has a deleterious effect on the cell's interior. Typically, in classical cell membrane electroporation, electrical current is delivered as a pulsed electric field in the form of brief pulses (e.g., having a duration of 0.1 to 20 milliseconds (ms)) between closely spaced electrodes capable of delivering a field strength of approximately 0.1 to 1.0 kilovolts per centimeter (kV / cm). System 10 may be used, for example, for high-power (e.g., high voltage and / or high current) electroporation procedures. In certain embodiments, system 10 is configured to deliver an electroporation pulse signal having a relatively high voltage and a short pulse duration.

[0048] In one embodiment, all electrodes on the catheter deliver current simultaneously. Alternatively, in other embodiments, stimulation is delivered between pairs of electrodes on the catheter. Using multiple electrodes to deliver current simultaneously can facilitate creating lesions deep enough for electroporation. To facilitate switching between i) simultaneously activating electrodes to deliver energy and ii) activating electrodes to sense signals (e.g., independently of each other), the electrodes may be switchable between being connected to a 3D mapping system and an EP amplifier.

[0049] Although the energization strategy 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. Additionally, in some embodiments, AC pulses may be used.

[0050] 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. Therefore, electroporation may avoid some of the thermal effects that can occur when using radio frequency (RF) energy. This "cold therapy" has such a desirable characteristic.

[0051] 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 therapy 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 therapy on a variety of other body tissues.

[0052] FIG. 1 further illustrates multiple return electrodes, designated 18, 20, and 21, which illustrate 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 visualizing, mapping, and navigating internal body structures. In the illustrated embodiment, the return electrodes 18, 20, and 21 are patch electrodes. The illustration of a single patch electrode is schematic (for clarity), and it should be understood that the subsystems to which these patch electrodes are connected may include multiple patch (body surface) electrodes, typically including multiple patch (body surface) electrodes, and may include split patch electrodes (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 components.

[0053] 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 electroporation-induced primary apoptosis therapy, the generator 26 may be configured to generate current delivered through the electrode assembly 12 as a pulsed electric field in the form of brief DC pulses (e.g., nanosecond to millisecond duration, 0.1 to 20 millisecond 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. As the pulse duration decreases, the amplitude must increase to achieve electroporation.

[0054] The electroporation generator 26, sometimes referred to herein as a DC energy source, is a monophasic electroporation generator 26 configured to generate a series of DC energy pulses that all generate current in the same direction. In other embodiments, the electroporation generator is a biphasic or polyphasic electroporation generator configured to generate DC energy pulses that do not all generate current in the same direction. 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, 200 joules, etc. 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 200 joule output level. 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 200 joule output level. In some embodiments, the peak magnitude may be even greater (e.g., on the order of 10,000 V). In other embodiments, any other suitable positive or negative voltage may be output. For example, in some embodiments, the systems and methods described herein may include pulses having amplitudes of about 500 V to about 4,000 V with pulse widths of about 200 nanoseconds to about 20 microseconds.

[0055] In some embodiments, variable impedance 27 allows for varying 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.

[0056] In other embodiments, one or more semiconductor devices connected in series with the catheter 14 may be used to limit arcing. For example, specially designed semiconductor devices derived from field-effect transistors can be implemented, which are two-terminal devices that can act very quickly to limit current and power. Two of these devices may be used for biphasic energy delivery and one for monophasic energy delivery. While commercially available devices are designed for low current, typically in the milliampere range, semiconductor devices for PFA applications can be engineered by modifying the size and / or dopant concentration of existing devices. This may improve patient safety and allow for repeated use of the catheter and generator.

[0057] 1, as noted above, catheter 14 may include functionality for electroporation and, in certain embodiments, may also include other types of ablation (e.g., RF ablation). However, it should be understood that variations are possible in those embodiments regarding the type of ablation energy provided (e.g., cryoablation, ultrasound, etc.).

[0058] 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.

[0059] The handle 42 provides a location for the clinician to grasp 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 another embodiment, 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 instruments 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 instruments, 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.

[0060] In some embodiments, the catheter 14 includes a basket catheter assembly having a catheter electrode (not shown in FIG. 1) disposed in a basket structure at the distal end of the shaft 44. Additionally, as described herein, an inflatable balloon may be housed within the basket structure.

[0061] A localization and navigation system 30 may be provided for visualization, mapping, and navigation of internal body structures. The localization and navigation system 30 may include conventional devices commonly known in the art (e.g., the EnSite Precision™ system, commercially available from Abbott Laboratories and generally shown with reference to commonly assigned U.S. Patent No. 7,263,397, entitled "Method and Apparatus for Catheter Navigation and Location and Navigation," the entire disclosure of which is incorporated herein by reference). However, it should be understood that this system is exemplary and not limiting in nature. Other techniques for positioning / navigating (and visualizing) a catheter in space are known, including, for example, Biosense Webster's CARTO navigation and positioning system, Boston Scientific CyMed's Rhythmia® system, Koninklijke Philips NV's KODEX® system, Northern Digital's AURORA® system, commonly available fluoroscopic systems, or magnetic positioning systems such as Mediguide's gMPS system. In this regard, part of the localization and navigation system and / or visualization system will include a sensor for generating a signal indicative of catheter position information, which may include, for example, one or more electrodes in the case of an impedance-based localization system, or alternatively, one or more coils (e.g., 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, as generally described with reference to U.S. Patent No. 7,536,218, entitled "Hybrid Magnetic-Based and Impedance-Based Position Sensing." The disclosure of U.S. Patent No. 7,536,218 is incorporated herein by reference in its entirety.

[0062] Pulsed field ablation (PFA) has been shown to be an effective form of ablation for the treatment of cardiac arrhythmias, particularly for instantaneous pulmonary vein isolation (PVI). PFA involves delivering high-voltage pulses from electrodes placed on a catheter (e.g., including the basket catheters and / or balloon catheters described herein). In PFA, for example, the voltage amplitude may range from about 300 V to at least 3,200 V (or even as great as on the order of 10,000 V), and the pulse width may range from hundreds of nanoseconds to tens of milliseconds.

[0063] These fields may be applied between adjacent electrodes (bipolar approach) or between one or more electrodes and a return electrode (monopolar approach).

[0064] With appropriate electrode geometry and catheter placement, both approaches can produce continuous lesions. Regarding lesion size and proximity, the monopolar approach potentially allows for deeper lesions with the same applied voltage. Furthermore, the monopolar approach potentially allows for lesions to be created from a distance (e.g., generally in proximity, but not necessarily in contact with the tissue). The bipolar approach may create smaller lesions, which require proximity and contact with the tissue to create a percutaneous lesion.

[0065] To monitor the operation of system 10, one or more impedances between the catheter electrodes and / or return electrodes 18, 20, 21 may be measured. For example, for system 10, impedance may be measured as described in U.S. Patent Application Publication No. 2019 / 0117113, filed October 23, 2018, U.S. Patent Application Publication No. 2019 / 0183378, filed December 19, 2018, and U.S. Patent Application No. 63 / 027,660, filed May 20, 2020, all of which are incorporated herein by reference in their entireties.

[0066] The embodiments disclosed herein include catheters that can perform both mapping and ablation functions. Generally, the embodiments disclosed herein include catheters with an increased density of electrodes at the tip and distal portion (compared to at least some known systems), which allows for higher resolution and, in turn, improves the system's ability to define and locate arrhythmia characteristics.

[0067] The embodiments described herein enable higher resolution mapping, producing higher fidelity electrograms (EGMs) and improving the signal-to-noise ratio (SNR). Higher resolution mapping improves mapping of boundaries / edges (e.g., scar tissue edges). These embodiments also provide improved techniques for detecting contact between the catheter and patient tissue. Additionally, the embodiments described herein provide omnidirectional mapping (OT) techniques in both two and three dimensions of the catheter body. Furthermore, these embodiments may reduce the manufacturing costs of the catheter assembly.

[0068] The catheter assemblies described herein include electrodes in various configurations. The electrodes may operate independently of one another (in an "unganged" configuration) or may function together as a larger effective electrode (in a "ganged" configuration). For example, electrodes operating independently of one another may be used for mapping and / or EGM applications. In contrast, multiple electrodes may be tied together to function as a combined electrode for ablation and / or near-field impedance navigation applications. Furthermore, different subsets of electrodes may be selectively activated (relative to one another) to improve control of the ablation procedure.

[0069] As described in detail below, the present disclosure provides catheter designs (e.g., linear, circular, basket) that enable both cardiac mapping (particularly OT) and ablation without the need for separate catheters for mapping and ablation, or separate catheters for different ablation modalities.

[0070] The ability to map the local electrical activity of cardiac tissue before ablation can improve the treatment of cardiac arrhythmias by selective ablation of cardiac tissue, especially when OT and map visualization tools are used to confirm the true source of the arrhythmia. This allows for almost immediate treatment of the arrhythmia source without removing the diagnostic catheter and inserting an ablation catheter. This is particularly important because it is generally not feasible to identify the site and rhythm after removing the diagnostic catheter and then inserting an ablation catheter that does not support similar mapping techniques and electrode configurations.

[0071] At least some of the embodiments described herein provide multimodal ablation systems and hybrid catheter designs with mini-electrodes arranged in an array (e.g., a square array) that accommodates OT. Additionally, the mini-electrodes can serve to construct local tissue resistance load measurements. Such measurements improve contact assessment between the tissue and the catheter.

[0072] The ablation component allows for the delivery of energy to and / or the removal of heat from tissue. In at least some embodiments, the mapping component can generate one or more distinct maps. The OT component uses, for example, an array of mini-electrodes on the hybrid catheter designs provided herein.

[0073] The present disclosure also provides a processor capable of selectively controlling the delivery of one or more different forms of therapeutic energy and selectively activating and controlling one or more energy treatment devices. Additionally, methods for applying therapeutic energy to a target tissue region using multiple ablation techniques are provided. For example, one method includes first providing a therapeutic energy generation station capable of delivering one or more different forms of therapeutic energy to one or more energy treatment devices coupled to the therapeutic energy generation station. The therapeutic energy is then selectively delivered to the one or more energy treatment devices. The target tissue region is ablated using the one or more energy treatment devices.

[0074] Thus, a hybrid catheter design with mini-electrodes that enables PT and local impedance estimation is provided. Furthermore, a multi-mode ablation system capable of delivering various energy types (e.g., cryoablation, microwave ablation, PFA, RF) is provided, as well as a system that allows selective control and utilization of the catheter to perform various ablation strategies. While OT cardiac-based mapping, RF ablation, PFA, microwave ablation, cryoablation, and other ablation techniques are all useful, it can be inconvenient, ineffective, and expensive to remove and replace an existing catheter to effectively map and ablate a tissue region with a different form of ablation. Furthermore, physicians have noted that, for example, grid catheters that exhibit excellent electrogram characteristics and have OT capabilities (e.g., Advisor™ HD Grid Mapping Catheter and Sensor Enabled™ (SE) mapping catheter) can be very difficult to obtain the same view of signals and arrhythmias when placed far from the site of interest. This makes it difficult to perform the ablation procedure as precisely as desired. The ablation system of the present disclosure provides a unique catheter design that enables OT mapping and can interface with existing catheters of any design to effectively treat tissue treatment areas.

[0075] 2 is a perspective view of one embodiment of a catheter assembly 200 that can be used with system 10 (shown in FIG. 1). For example, catheter assembly 200 may be implemented as part of catheter 14. Catheter assembly 200 includes a tip electrode array 202, a mini-electrode array 204, and a plurality of ring electrodes 206. In this embodiment, ring electrodes 206 are proximal to mini-electrode array 204, and tip electrode array 202 is distal to mini-electrode array 204.

[0076] 2, the tip electrode array 202 includes a plurality of tip electrodes 208 separated by non-conductive segments 209. Specifically, the tip electrode array 202 includes four tip electrodes 208 separated by four non-conductive segments 209. The tip electrode array 202 also has a dome shape.

[0077] 2, the mini-electrode array 204 includes a plurality of rectangular electrodes 210 wrapped around the circumference of the catheter assembly 200. Furthermore, the rectangular electrodes 210 are arranged in a brick pattern on a non-conductive substrate 212 that insulates the rectangular electrodes 210 from one another.

[0078] In mapping applications, the tip electrode 208 and rectangular electrode 210 may function or be activated independently of one another (i.e., may sense voltage independently of one another, may be energized independently of one another, may be energized with different polarities, and / or may be energized with different voltages). For example, using the tip electrode 208 and rectangular electrode 210 to sense voltage independently of one another facilitates obtaining navigation impedance information and generating independent electrograms that can be used to accurately map the catheter.

[0079] In contrast, in ablation applications, two or more of the tip electrode 208 and rectangular electrodes 204 are activated together to form a larger effective electrode. For example, if all of the rectangular electrodes 204 are activated together, they effectively function as a ring electrode (similar to multiple ring electrodes 206). Those skilled in the art will appreciate that any suitable combination of electrodes may be activated together.

[0080] Figure 2 shows an example of a catheter assembly including a tip electrode array and a mini-electrode array. Those skilled in the art will appreciate that many other configurations are possible. For example, Figures 3A through 3E are perspective views of alternative catheter assemblies.

[0081] 3A shows a catheter assembly 302 including a tip electrode array 304 and a mini-electrode array 306. The tip electrode array 304 includes multiple tip electrodes 308 separated by non-conductive segments 310. Here, the tip electrode array 304 also has a flat shape (as opposed to the dome-shaped shaft of the tip electrode array 202 (shown in FIG. 2)).

[0082] 3A, the mini-electrode array 306 includes a plurality of rectangular electrodes 312 wrapped around the circumference of the catheter assembly 302. Furthermore, the rectangular electrodes 312 are arranged in a brick pattern on a non-conductive substrate 314 that insulates the rectangular electrodes 312 from one another.

[0083] 3B shows a catheter assembly 322 that includes a tip electrode array 324 and a mini-electrode array 326. The tip electrode array 324 includes multiple tip electrodes 328 separated by non-conductive segments 330. Here, the tip electrode array 324 has a flat shape.

[0084] 3B, the mini-electrode array 326 includes a plurality of circular electrodes 332 arranged around the periphery of the catheter assembly 322. Furthermore, the circular electrodes 332 are arranged in a spaced apart pattern on a non-conductive substrate 334 that insulates the circular electrodes 332 from one another.

[0085] 3C shows a catheter assembly 342 including a tip electrode array 344 and a mini-electrode array 346. The tip electrode array 344 includes multiple tip electrodes 348 separated by non-conductive segments 350. Here, the tip electrode array 344 has a flat shape.

[0086] 3C, the mini-electrode array 346 includes a plurality of circular electrodes 352 disposed around the periphery of the catheter assembly 342. Furthermore, the circular electrodes 352 are arranged in a spaced apart pattern on a non-conductive substrate 354 that insulates the circular electrodes 352 from one another.

[0087] 3D shows a catheter assembly 362 including a tip electrode array 364 and a mini-electrode array 366. The tip electrode array 364 includes multiple tip electrodes 368 separated by non-conductive segments 370. Here, the tip electrode array 364 has a dome shape.

[0088] In the embodiment of FIG. 3D, the mini-electrode array 366 includes a plurality of circular electrodes 372 disposed around the circumference of the catheter assembly 362. Furthermore, the circular electrodes 372 are arranged in a spaced apart pattern. In this embodiment, an annular electrode 373 extends around the circumference of the catheter assembly 362, with the circular electrodes 372 disposed within openings defined by the annular electrode 373. A non-conductive substrate 374 insulates the circular electrodes 372 from each other and from the annular electrode 373. During ablation applications, the circular electrode 372 and the annular electrode 373 may be actuated together to function as a ring electrode.

[0089] 3E shows a catheter assembly 382 including a tip electrode array 384 and a mini-electrode array 386. The tip electrode array 384 includes multiple tip electrodes 388 separated by non-conductive segments 390. Here, the tip electrode array 384 has a flat shape.

[0090] In the embodiment of FIG. 3E, the mini-electrode array 386 includes a plurality of circular electrodes 392 disposed around the circumference of the catheter assembly 382. Furthermore, the circular electrodes 392 are arranged in a spaced apart pattern. In this embodiment, an annular electrode 393 extends around the circumference of the catheter assembly 382, ​​with the circular electrodes 392 disposed within openings defined by the annular electrode 393. A non-conductive substrate 394 insulates the circular electrodes 392 from each other and from the annular electrode 393. During ablation applications, the circular electrode 392 and the annular electrode 393 may be actuated together to function as a ring electrode.

[0091] Figure 4A is a perspective view of another embodiment of a tip electrode array 400, and Figure 4B is an exploded view of the tip electrode array 400. The tip electrode array 400 includes multiple tip electrodes 404 separated by non-conductive segments 406. Specifically, the tip electrode array 400 includes four tip electrodes 404 separated by four non-conductive segments 406. The tip electrode array 400 also has a dome shape. As best shown in Figure 4B, in this embodiment, the non-conductive segment 406 is formed by a single non-conductive insert 408 inserted between the four tip electrodes 404.

[0092] 5 is a perspective view of another embodiment of a catheter assembly 500. The catheter assembly 500 includes a tip electrode array 502 and a mini-electrode array 504. The tip electrode array 502 includes a plurality of circular tip electrodes 506 arranged in a grid. In addition, the mini-electrode array 504 includes a plurality of circular electrodes 508 arranged in a grid around the circumference of the catheter assembly 500. The circular tip electrode 506 and the circular electrode 508 are disposed within openings defined in a base 510. In some embodiments, the base 510 is conductive (and may be activated together with the circular tip electrode 506 and / or the circular electrode 508 for ablation applications), while in other embodiments, the base 510 is non-conductive.

[0093] 6A is a schematic diagram of one embodiment of a flex circuit architecture 600 that may be used to implement the catheter assemblies described herein. The flex circuit architecture 600 may be used, for example, to implement the mini-electrode arrays shown in FIGS. 2 through 5. Those skilled in the art will appreciate that the flex circuit architecture 600 may be wound into a loop to form the mini-electrode array.

[0094] The flex circuit architecture 600 includes a substrate 602 having an exterior surface 604. A plurality of electrodes 606 (e.g., platinum / iridium (Pt / Ir) electrodes) are disposed on the exterior surface 604. Wiring 608 for supplying energy to the electrodes 606 extends through the substrate 602 and connects to the backside of the electrodes 606.

[0095] 6B is a schematic diagram of an alternative embodiment of a flex circuit architecture 620 that may be used to implement the catheter assemblies described herein. The flex circuit architecture 620 may be used to implement the mini-electrode arrays shown in FIGS. 2-5, for example. Those skilled in the art will appreciate that the flex circuit architecture 620 may be wound into a loop to form the mini-electrode array.

[0096] Flex circuit architecture 620 includes a substrate 622 having an outer surface 624. Here, in contrast to flex circuit architecture 600, multiple electrodes 626 are embedded beneath outer surface 624. Additionally, wiring 628 for supplying energy to electrodes 626 connects to the outer surface of solder pads 630 (e.g., Pt / Ir pads), which are electrically connected to one or more electrodes 626.

[0097] 7 is a schematic diagram of another embodiment of a catheter assembly 700. The catheter assembly 700 includes a tip electrode array 702, a first mini-electrode array 704, a second mini-electrode array 706, and a ring electrode 708. The tip electrode array 702 includes a first tip electrode 710 and a second tip electrode 712. The first mini-electrode array 704 includes a plurality of circular electrodes 720 and a conductive substrate 722, and the second mini-electrode array includes a plurality of circular electrodes 730 and a non-conductive substrate 732. Those skilled in the art will understand that the catheter assembly 700 includes an exemplary configuration of electrodes, and that other arrangements of electrodes are within the spirit and scope of the present disclosure.

[0098] 7 shows electric field lines 750 representing the electric field that occurs when the first tip electrode 710 and the second tip electrode 712 are used in a bipolar configuration (i.e., with a voltage developed between the first tip electrode 710 and the second tip electrode 712). Those skilled in the art will appreciate that any suitable pair of electrodes from among the tip electrode array 702, the first mini-electrode array 704, the second mini-electrode array 706, and / or the ring electrode 708 may be used in a bipolar configuration.

[0099] 8A is a schematic diagram of one embodiment of a mapping and ablation system 800. System 800 is capable of performing both RF ablation and PFA, as well as other ablation types (e.g., microwave ablation and cryoablation). System 800 includes a console 802, a catheter 804, and a cable system 803 coupling console 802 and catheter 804.

[0100] Catheter 804 may be, for example, a linear catheter, a loop catheter, and / or any other suitable energy treatment device that can move easily and smoothly through blood vessels and heart valves. Cable system 803 includes electrical signal lines for monitoring and / or mapping tissue and cardiac regions and may be coupled to mapping system 807 and ECG / electrogram monitor 808. Cable system 803, in this embodiment, includes a cooling infusion cable system 810 and a vacuum cable system 812 that provide respective inlet and return paths for coolant used to cool the tissue treatment end of catheter 804.

[0101] Console 802 provides a user interface for system 800, controls and records the mapping and ablation procedures, and houses the electronics and software for controlling the delivery of liquid coolant under pressure to catheter 804 through cable system 803, controlling the recovery of expanded coolant vapor from catheter 804 under vacuum, and controlling a compressor for pressurizing the coolant vapor into a liquid stored in a recovery tank. In addition to the liquid coolant, secondary heat removal or dissipation elements, such as conductive coils, may be used.

[0102] The system 800 generates controlled temperature and / or pulses at the tip of the catheter 804. One or more selected catheters 804 may be coupled to the console 802. For example, FIG. 8B shows the system 800 with two catheters 804 connected. Generally, the catheters 804 are long and flexible enough to be inserted through various body conduits. The system 800 may be used with catheters designed for both endovascular and open procedures. The system 800 may be configured to deliver more than one type of energy to the catheter 800 (e.g., the system 800 may be used with a catheter 804 suitable for PFA, RF ablation, cold-tip RF ablation, microwave ablation, cryoablation, and / or mapping procedures—particularly OT). At least one of the catheters 804 may be a focal-tip catheter that generates a focused zone of tissue destruction (i.e., ablation), a linear catheter that delivers cold air along the length of the catheter, or a loop catheter suitable for PVI isolation.

[0103] 8A and 8B, a radio frequency generator 820 is coupled to a generator hub 822. Using the controls on console 2, a user may select the type of ablation procedure they wish to perform.

[0104] The catheter 804 may include one or more electrodes therearound. If a user desires to perform an RF ablation procedure, radio frequency energy can be supplied to the electrodes of the catheter 804 via the cable system 803 to perform an RF ablation procedure as is common in the art for cardiac ablation procedures. Specifically, RF energy is supplied between an electrode located on or within the catheter 804 and an indifferent electrode 824 (also known as a collector plate). The indifferent electrode 824 may be positioned, for example, on the patient's body. The RF energy flows through the patient's tissue between the electrode on the catheter 804 and the indifferent electrode 824, causing cell death in or treating the target tissue.

[0105] In some embodiments, a conductive coolant may be supplied to the catheter 804, either by itself or simultaneously with the RF current supply, to complete the electrical connection to the electrodes. Direct current (DC) may also be supplied to the catheter 804.

[0106] The mechanisms underlying scar formation by DC shock are known in the field of electrophysiology and result in irreversible electroporation (IRE). Scar formation in IRE is a function of electric field exposure disrupting cell membrane permeability and homeostasis, leading to cell death while simultaneously preserving the integrity and function of nearby structures, such as the esophagus, lungs, coronary arteries, PV, and respiratory nerves.

[0107] As mentioned above, PFA is a form of IRE that uses a train of high-voltage, short-duration monophasic or biphasic pulses to induce cell death in tissue without significant heating (when waveform parameters are properly optimized). The tissue effect at the target site is directly controlled by the magnitude and duration of the applied electric field. Voltage directly affects the field strength distribution; increasing voltage increases treatment intensity. Increasing voltage magnitude increases tissue heating, muscle contraction, and the potential generation of gaseous microemboli (i.e., microbubbles).

[0108] In the case of PFA, when multiple pulses are delivered in rapid succession (e.g., on a nanosecond to millisecond timeframe), the effect can be viewed as a collective pulse called a packet. As multiple packets are delivered to tissue, cumulative injury to cells increases. Therefore, the more packets used, the stronger the therapeutic effect; however, the longer the therapeutic delivery time (when combined with the packet delivery rate) and the greater the cumulative temperature rise if there is insufficient time for heat dissipation between subsequent packets. Pause periods between successive pulses or packets allow the tissue an opportunity to conduct heat away from the warmed tissue, thereby reducing the total temperature rise. When a series of pulses is delivered with relatively large pauses (milliseconds to tens of seconds), cell recovery is generally unaffected, but the overall tissue temperature rise is reduced. This allows for a powerful cumulative treatment while maintaining an acceptable level of temperature rise.

[0109] 8B, in addition to RF generator 820, a PFA generator 830 may also be coupled to hub 822. PFA energy may also be delivered to the patient through catheter 804. Those skilled in the art will appreciate that in other embodiments, other energy sources (e.g., a cryoablation generator) may be selectively coupled to hub 822.

[0110] Thus, system 800 allows for various combinations of different types of ablation energy to be delivered to one or more catheters 804 that ablate a target tissue region. The ablation procedures may be performed sequentially depending on the desired therapeutic strategy for treating the tissue. The ability to quickly switch from one ablation procedure to another may lead to better treatment outcomes for tissue lesions.

[0111] For example, in one scenario, if a physician desires to create a deep lesion, the tissue may first be cryoablated for 45 seconds until localized edema occurs, after which RF ablation may be performed after extracellular fluid has accumulated near the tissue region, allowing the RF energy to more easily spread deeper into the tissue region.

[0112] In another example, a target tissue region near the esophagus is mapped in combination with OT. For this purpose, a shallow incision, e.g., 1–3 mm deep, is sufficient to achieve isolation. PFA alone is then applied, with a user-defined field strength of approximately 300 V / cm.

[0113] As yet another example, suppose a physician wishes to administer PFA to a limited area. Cryoablation may be performed first. Note that when PFA is applied within the low-temperature ice produced by cryoablation, the PFA becomes trapped within the ice, allowing direct visualization of the ablated area using conventional imaging techniques.

[0114] FIG. 9 is a schematic diagram of one embodiment of a catheter assembly 900 that can be used with system 800 (shown in FIGS. 8A and 8B) or system 10 (shown in FIG. 1). The catheter assembly 900 is a linear assembly including a plurality of ring electrodes 902. Additionally, for at least some of the ring electrodes 902, a mini-electrode array 904 is formed around the ring electrode 902. In this embodiment, each mini-electrode array 904 includes four mini-electrodes 906 arranged in a square grid, with the mini-electrodes 906 spaced equally apart from one another. While one mini-electrode array 904 is shown on each ring electrode 902, in some embodiments, a single ring electrode 904 may include two or more mini-electrode arrays 902 thereon.

[0115] The mini-electrode array 904 may be used to tailor the application of electrical energy (e.g., to generate omnidirectional patterns and / or directional application of pacing, RF, or PFA energy). Furthermore, the mini-electrode array 904 takes advantage of OT, sensing consistent voltage signals regardless of orientation, allowing for detection of wave propagation speed and direction. Specifically, the square arrangement of the mini-electrode array 904 supports OT mapping techniques, and the mini-electrode array 904 may be used with multiple catheter designs (e.g., linear or loop catheters). Using a mapping system, the grid arrangement of the mini-electrode array 904 allows for electrogram display of directional characteristics, propagation speed, and / or maximum voltage, regardless of catheter orientation. Furthermore, the mini-electrode array 904 can be used to locally measure the impedance load at the tissue-catheter interface, thereby improving differentiation between the myocardium and the blood pool. The impedance load on the distal electrode of an ablation catheter is significantly affected by the ratio of the surface area covered by myocardium and blood. The impedance of the myocardium is greater than that of the blood pool (e.g., 3.0 to 6.0 Ω·m and 1.5 Ω·m, respectively). Notably, the increased resistivity of the myocardium is responsible for preferential Joule heating compared to blood.

[0116] Several techniques have attempted to measure the resistive load at the catheter-tissue interface via impedance. Traditionally, RF generators calculate the resistive load via the transthoracic impedance of the energy delivery path from the ablation catheter tip electrode to an indifferent electrode on the skin. While RF generators can reasonably calculate the tissue-to-blood impedance difference, they are hampered by the large variations in bulk impedance of the body, including muscle, lung, and bone.

[0117] In contrast, using the embodiments described herein, resistive loads can be measured more locally by utilizing a mini-electrode array 904 integrated into a larger ring electrode 902. For example, a non-stimulatory alternating current may be driven between distal and proximal electrodes of a linear ablation catheter to create a local electrical potential field. Mini-electrodes 906 can then be used to measure variations in the electrical potential field that may be due to nearby cardiac tissue. The measured electrical potential can be converted to impedance by dividing by the injected current.

[0118] Catheter impedance is known to plateau before reaching a dangerous contact force. Therefore, local impedance measurements of ablation catheters serve as a surrogate for the distal electrode surface area covered by myocardium. Although contact force may offer safety benefits, force values ​​are unreliable predictors of catheter-tissue surface area and resistive heating during radiofrequency treatment. For example, a catheter gently placed in the corpus cavernosum may have a low contact force, but because the distal electrode is covered by tissue, it can deliver significant radiofrequency energy to the myocardium.

[0119] FIG. 10A is a perspective view of one embodiment of a catheter assembly 1000 that can be used with system 800 (shown in FIGS. 8A and 8B). FIG. 10B is an end view of the catheter assembly 1000. As shown in FIGS. 10A and 10B, the catheter assembly 1000 is a loop assembly. The catheter assembly 1000 includes a plurality of ring electrodes 1002. Furthermore, at least some of the ring electrodes 1002 have mini-electrode arrays 1004 formed thereon (see enlarged portion). In this embodiment, each mini-electrode array 1004 includes four mini-electrodes 1006 arranged in a square grid, with the mini-electrodes 1006 being equally spaced apart from one another. While one mini-electrode array 1004 is shown on each ring electrode 1002, in some embodiments, a single ring electrode 1004 may include two or more mini-electrode arrays 1002 thereon. The mini-electrode arrays 1004 function substantially similarly to the mini-electrode array 904 (shown in FIG. 9).

[0120] The catheter assembly 1000, in this embodiment, includes nine ring electrodes 1002 (e.g., a central electrode (“C”) and eight outer electrodes (“D,” “2,” “3,” “4,” “5,” “6,” “7,” and “8”) adjacent to or surrounding the central electrode. The central electrode may or may not be coplanar with the outer electrodes. Additionally, in some embodiments, the catheter assembly 100 includes two central electrodes: one in the same plane as the outer electrodes and one outside that plane.

[0121] Alternatively, the catheter assembly 1000 may include any suitable number of ring electrodes 1002. The catheter assembly 1000 may be useful for pulmonary vein ablation. It may be powered by a duty-cycled radiofrequency (RF) generator or a specially designed PFA generator. The catheter assembly 1000 may efficiently create continuous transmural lesions capable of PV isolation. Additionally, pulsed electric field energy delivery is also possible through the catheter assembly 1000, which can create continuous transmural myocardial lesions like RF energy. The PFA energy design may be configured to deliver a high-voltage bipolar pulse train to the catheter assembly 1000 via a cable connecting electrodes 1002 "D," "3," "5," and "7" as one polarity and electrodes 1002 "2," "4," "6," and "8" as the opposite polarity. Duty-cycled RF energy may be delivered for 60 seconds in each configuration, with a 2:1 bipolar / unipolar ratio, a maximum power of 10 watts (W) per electrode, and a temperature setpoint of 60°C. The PF energy can be delivered as a biphasic pulse train with a pulse width of 100 microseconds (μs) per phase and a 200 μs interpulse pause, although those skilled in the art will appreciate that these parameters are merely an example of possible parameters.

[0122] In an electroanatomical mapping scenario, a user applies a set of mapping settings via a menu on the monitor 808 (shown in FIG. 8). Specifically, the monitor 808 may be used to select various map types for examining electrograms of interest on the display. Because the spacing between the mini-electrodes is relatively small, generally only localized information is provided to the physician. However, loop catheters such as the catheter assembly 1000 can be configured to provide both localized and magnified views of the target area.

[0123] 8A and 8B, catheter 804 may be any suitable RF ablation, PFA, microwave ablation, and / or cryoablation catheter, as well as a hybrid catheter capable of ablating tissue via a combination of PFA, RF, microwave ablation, and cryoablation. A computing device (e.g., included in console 802) allows a user to selectively control which catheter 804 receives a selected energy type. The user may, for example, choose to treat the target tissue with a conventional RF procedure. Additionally, mapping may be performed prior to the ablation procedure.

[0124] Alternatively, the user may choose to treat the target tissue using a PFA procedure. The computing device is then instructed to access a PFA-enabled catheter 804 already connected to the system via the cable system 3. Before the PFA lesion is created, electroanatomical mapping may be performed first. This may be accomplished by first activating the desired catheter 804 for mapping the desired area. By first activating a compatible cryotherapy catheter, microwave catheter, RF ablation catheter, or PFA catheter, the target tissue can be treated with any combination of ablation procedures. Furthermore, the same catheter can be used to immediately track ablation with remapping to assess the effectiveness of the treatment application. In this manner, multiple maps and a wide temperature range can be achieved without the need to change and / or replace one type of catheter 804 with another.

[0125] Using the embodiments described herein, any desired combination of ablation procedures may be performed on a target tissue region. For example, ablation may be performed with or without a prior mapping procedure. Furthermore, any suitable sequence of ablation procedures may be performed. For example, RF ablation may be followed by PFA, particularly in areas near circulatory "heat sinks" such as blood vessels, where conventional ablation techniques are known to limit scar formation.

[0126] Multi-mode procedures may also be performed in which a series of ablation procedures are programmed and automatically controlled by a computerized device, with the user providing inputs to the computerized device that send activation signals to the appropriate catheters 804, controlling the type of energy delivered and auxiliary functions such as circulating a cooling fluid through the catheters 804.

[0127] Using the embodiments described herein, RF ablation, PFA, microwave ablation, and / or cryoablation may also be performed simultaneously. That is, different types and amounts of ablation energy may be delivered to catheters 804 to perform simultaneous ablation procedures. For example, in a multi-catheter scenario, one catheter 804 may receive coolant for a cryoablation procedure, while RF energy may be supplied to another catheter 804 via RF generator 820, and PFA energy may be supplied to yet another catheter 804. Additionally, microwave energy may be applied to yet another catheter 804.

[0128] The embodiments described herein are not limited to a particular number of catheters or a particular sequence of ablation sequences. The multi-energy ablation systems described herein allow for a variety of different types of probes or catheters, each capable of performing one or more ablation procedures, coupled to a control system that selectively delivers the various types of energy necessary to map and ablate regions of the body. Such a system would be highly useful to cardiac electrophysiology practitioners, particularly because it may overcome the shortcomings of various ablation modalities in at least some known systems.

[0129] FIG. 11A is a side view of another embodiment of a catheter assembly 1100 that may be used with the systems and methods described herein (e.g., system 10 shown in FIG. 1 or system 800 shown in FIGS. 8A and 8B). For example, catheter assembly 1100 may be implemented as part of catheter 14. Catheter assembly 1100 includes a tip electrode array 1102 and a plurality of ring electrodes 1106. FIG. 11B is a perspective view of tip electrode array 1102.

[0130] 11A and 11B, the tip electrode array 1102 includes a plurality of tip electrodes 1108 separated by non-conductive segments 1109. Specifically, the tip electrode array 1102 includes four tip electrodes 1108 separated by four non-conductive segments 1109. The tip electrode array 1102 also has a generally spherical shape. The non-conductive segment 1109 may be formed by a single non-conductive insert similar to the non-conductive insert 408 (shown in FIG. 4B).

[0131] The shape of the tip electrode array 1102 enables the catheter assembly 1100 to produce a relatively uniform lesion regardless of the contact angle between the catheter assembly 1100 and the patient's tissue. That is, use of the catheter assembly 1100 can prevent or significantly reduce the occurrence of shadow lesions (e.g., lesions inadvertently caused during treatment). The tip electrode array 1102 may have any suitable size. For example, in some embodiments, the spherical portion of the tip electrode array 1102 has a diameter of approximately 4.19 mm, 3.94 mm, or 2.34 mm.

[0132] The relatively large diameter of the tip electrode array 1102 may have other advantages as well, for example, a larger diameter necessarily reduces the rate at which local field strength decreases, implying a more uniform RF and PFA effect radius.

[0133] Figure 12A is a perspective view of another embodiment of a catheter assembly 1200 that may be used with the systems and methods described herein (e.g., system 10 shown in Figure 1). For example, catheter assembly 1200 may be implemented as part of catheter 14. Catheter assembly 1200 includes a tip electrode array 1202 and a ring electrode 1204. Figure 12B is another perspective view of catheter assembly 1200.

[0134] As shown in FIGS. 12A and 12B, the tip electrode array 1202 includes a basket 1210 with a plurality of conductive splines 1212 that function as electrodes. The basket 1210 may have a diameter of, for example, approximately 1 centimeter (cm). In some embodiments, a pull member (e.g., a pull ring and / or pull wire) may be used to selectively increase the diameter of the basket 1210 (e.g., by approximately 0.152 mm). The splines 1212 may function as independent electrodes or may be activated together. Similar to the catheter assembly 1100 (shown in FIGS. 11A and 11B), the shape of the tip electrode array 1202 enables the catheter assembly 1200 to create a relatively uniform lesion regardless of the contact angle between the catheter assembly 1200 and the patient tissue. Furthermore, applying energy between the tip electrode (e.g., electrode 1108 in FIG. 11A) and the shaft electrode closest to the tip electrode (e.g., the leftmost ring electrode 1106 in FIG. 11A) also facilitates reducing the effect of the contact angle on the lesion shape.

[0135] 12A and 12B, each spline 1212 includes a single electrode. Alternatively, one or more splines of the basket catheter assembly may include multiple electrodes. For example, FIG. 13 is a perspective view of another embodiment of a catheter assembly 1300 that may be used with the systems and methods described herein (e.g., system 10 shown in FIG. 1). The catheter assembly 1300 includes a tip electrode array 1302 and a ring electrode 1304.

[0136] 13, the tip electrode array 1302 includes a basket 1310 having a plurality of splines 1312, each containing one or more electrodes. The basket 1310 may have a diameter of, for example, about 1 centimeter (cm). In some embodiments, a pull member (e.g., a pull ring and / or a pull wire) may be used to selectively increase the diameter of the basket 1310 (e.g., by about 0.152 mm).

[0137] In this embodiment, the first spline 1320 includes a plurality of ring electrodes 1322. Additionally, the second spline 1330 includes an elongated flexible post electrode 1332 and a plurality of flexible spot electrodes 1334. As shown, the flexible spot electrodes 1334 are smaller than the flexible post electrodes 1332. In this embodiment, the tip electrode array 1302 also includes a split tip electrode 1340 having four selectively activatable (e.g., together or independently of one another) quadrant electrodes 1342. Alternatively, the tip electrode array 1302 may include one or more electrodes in any suitable arrangement. For example, in some embodiments, the tip electrode array 1302 includes a single electrode.

[0138] For the first spline 1320, the ring electrodes 1322 may be activated together for ablation applications. Additionally, for mapping applications, the ring electrodes 1322 may be activated independently of one another. For the second spline 1330, for ablation applications, the flexible post electrode 1332 may be activated without activating the flexible spot electrode 1334 (or the flexible post electrode 1332 and one or more flexible spot electrodes 1334 may be activated together). For mapping applications, the flexible spot electrodes 1334 may be activated independently of one another (e.g., without activating the flexible post electrode 1332).

[0139] Those skilled in the art will understand that the first splines 1320 and the second splines 1330 are shown as being included in the same embodiment by way of example and for ease of illustration. That is, in some embodiments, a basket catheter assembly may include one or more first splines 1320 and no second splines 1330. In other embodiments, a basket catheter assembly may include one or more second splines 1330 and no first splines 1320. In still other embodiments, a basket catheter assembly may include a combination of one or more first splines 1320 and one or more second splines 1330 (e.g., as in catheter assembly 1300).

[0140] In the embodiments described herein, applying energy between one or more pairs of individual electrodes at the distal end of the device generally results in a more uniform lesion area. This uniformity of area can also be achieved by applying energy between i) some or all of the distal electrodes and ii) an internal or intracardiac return electrode.

[0141] Those skilled in the art will appreciate that the various embodiments of the catheter assembly described herein may be implemented independently of one another or in any suitable combination.

[0142] Embodiments described herein provide a catheter assembly including a tip electrode array including at least one tip electrode located at a distal end of the catheter assembly, and a mini-electrode array including a plurality of mini-electrodes located proximal to the tip electrode array, wherein each of the at least one tip electrode and each of the plurality of mini-electrodes are configured to be activated independently of one another for mapping applications, and at least some of the at least one tip electrode and the plurality of mini-electrodes are configured to be activated together for ablation applications.

[0143] While specific embodiments of the present disclosure have been described above with a certain degree of specificity, those skilled in the art could make numerous modifications to the disclosed embodiments without departing from the spirit or scope of the present disclosure. All directional references (e.g., upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, 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. References to joining (e.g., attaching, coupling, connecting, etc.) should be interpreted broadly and may include intermediate members between the joining of elements and relative movement between the elements. As such, a reference to joining does 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 interpreted as 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.

[0144] 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 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.

[0145] 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.

Claims

1. 1. A catheter assembly comprising: a tip electrode array located at a distal end of the catheter assembly, the tip electrode array comprising at least one tip electrode; a mini-electrode array located proximal to the tip electrode array, the mini-electrode array comprising a plurality of mini-electrodes; each of the at least one tip electrode and each of the plurality of mini-electrodes are configured to be activated independently of one another for mapping applications; the at least one tip electrode and at least a portion of the plurality of mini-electrodes are configured to be activated together for ablation applications. Catheter assembly.

2. The catheter assembly of claim 1 , wherein the plurality of mini-electrodes comprises a plurality of rectangular electrodes arranged in a brick pattern.

3. The catheter assembly of claim 1 , wherein the plurality of mini-electrodes comprises a plurality of circular electrodes.

4. further comprising an annular electrode defining a plurality of apertures; the plurality of mini-electrodes are located within the plurality of apertures; The catheter assembly of claim 1 .

5. the at least one tip electrode comprises a plurality of tip electrodes; the tip electrode assembly further comprising a plurality of non-conductive segments separating the plurality of tip electrodes; The catheter assembly of claim 1 .

6. The catheter assembly of claim 1 , wherein the mini-electrode array comprises four mini-electrodes arranged in a square grid pattern.

7. The catheter assembly of claim 1 further comprising a ring electrode.

8. The catheter assembly of claim 7 , wherein the plurality of mini-electrodes are formed on the ring electrode.

9. The catheter assembly of claim 1 , wherein the tip electrode array has one of a dome shape, a planar shape, a spherical shape, and a basket shape.

10. the catheter assembly is a basket catheter assembly having a plurality of splines; the mini-electrode array comprises at least one of i) a plurality of ring electrodes on a single spline, and ii) an elongated flexible post electrode and a plurality of flexible spot electrodes on a single spline; The catheter assembly of claim 1 .

11. 1. An electroporation system comprising: A generator; a catheter coupled to the generator; The catheter comprises: The handle and a shaft extending distally from the handle; a catheter assembly coupled to a distal end of the shaft; The catheter assembly includes: a tip electrode array located at a distal end of the catheter assembly, the tip electrode array comprising at least one tip electrode; a mini-electrode array located proximal to the tip electrode array, the mini-electrode array comprising a plurality of mini-electrodes; each of the at least one tip electrode and each of the plurality of mini-electrodes are configured to be activated independently of one another for mapping applications; the at least one tip electrode and at least a portion of the plurality of mini-electrodes are configured to be activated together for ablation applications. Electroporation system.

12. The system of claim 11 , wherein the plurality of mini-electrodes comprises a plurality of rectangular electrodes arranged in a brick pattern.

13. The system of claim 11 , wherein the plurality of mini-electrodes comprises a plurality of circular electrodes.

14. further comprising an annular electrode defining a plurality of apertures; the plurality of mini-electrodes are located within the plurality of apertures; The system of claim 11.

15. the at least one tip electrode comprises a plurality of tip electrodes; the tip electrode assembly further comprising a plurality of non-conductive segments separating the plurality of tip electrodes; The system of claim 11.

16. The system of claim 11 , wherein the catheter is a linear catheter.

17. The system of claim 11 , wherein the catheter is a loop catheter.

18. 1. An ablation system comprising: The console and at least one catheter; a cable system coupling the console to the at least one catheter; a hub coupled between the console and the at least one catheter; a first generator coupled to the hub, the first generator configured to deliver a first type of ablation energy to the at least one catheter through the hub; a second generator coupled to the hub, the second generator configured to deliver a second type of ablation energy to the at least one catheter through the hub; the console is configured to selectively control delivery of the first type of ablation energy and the second type of ablation energy to the at least one catheter via the hub. Ablation system.

19. 20. The ablation system of claim 18, wherein the first generator is a radio frequency generator and the second generator is a pulsed field ablation generator.

20. 20. The ablation system of claim 18, further comprising a mapping system coupled to the at least one catheter via the cable system.

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