Systems and methods for catheters with combined mapping and ablation functions

Abstract

A catheter assembly is provided. The catheter assembly comprises a tip electrode array, the tip electrode array comprises at least one tip electrode, and the tip electrode array is located at the far end of the catheter assembly; and a microelectrode array comprising a plurality of microelectrodes, the microelectrode array being located at a proximal end of the tip electrode array, where each of the at least one tip electrode and each of the plurality of microelectrodes are configured to be activated independently of each other for a mapping application, and where the microelectrode array comprises a plurality of microelectrodes, the microelectrode array being located at a proximal end of the tip electrode array, at least some of the at least one tip electrode and the plurality of microelectrodes are configured to be synchronously activated for an ablation application.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 426,533, filed on November 18, 2022, and U.S. Provisional Patent Application No. 63 / 533,003, filed on August 16, 2023, both of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure generally relates to tissue ablation systems. In particular, the present disclosure relates to catheters that can be used for mapping and ablation applications. Background Art

[0004] It is well known that ablation therapy can be used to treat various diseases that affect the human anatomy. For example, ablation therapy can be used to treat atrial arrhythmias. When tissue is ablated, or at least subjected to ablation energy generated by an ablation generator and delivered by an ablation catheter, lesions are formed in the tissue. Electrodes mounted on or within the ablation catheter are used to cause cell death in cardiac tissue (e.g., by apoptosis or necrosis) to correct diseases such as atrial arrhythmias (including but not limited to ectopic atrial tachycardia, atrial fibrillation, and atrial flutter).

[0005] Arrhythmias (i.e., irregular heart rhythms) can cause a variety of dangerous conditions, including the loss of atrioventricular synchronous contraction and blood flow stasis, which can lead to a variety of diseases and even death. The primary cause of atrial arrhythmias is believed to be stray electrical signals within the left or right atrium of the heart. The ablation catheter applies ablation energy (e.g., radiofrequency energy, cryoablation, laser, chemicals, high-intensity focused ultrasound, etc.) to the cardiac tissue, thereby creating lesions in the cardiac tissue. Such lesions disrupt unwanted electrical pathways, thereby limiting or preventing stray electrical signals that cause arrhythmias.

[0006] Electroporation is a non-thermal ablation technique that involves applying a strong electric field to induce the formation of pores in cell membranes. The electric field can be induced by applying pulses of relatively short duration, which can last for example from 1 nanosecond to several milliseconds. Such pulses can be repeated to form a pulse sequence. When such an electric field is applied to tissue in a body environment, the cells in the tissue are subjected to a transmembrane potential, which opens pores in the cell wall. Electroporation can be reversible (i.e., the temporarily opened pores will reseal) or irreversible (i.e., the pores will remain open). For example, in the field of gene therapy, reversible electroporation (i.e., temporarily opening pores) is used to transfect high molecular weight therapeutic vectors into cells. In other therapeutic applications, an appropriately configured pulse sequence can be used alone to cause cell destruction, for example by causing irreversible electroporation.

[0007] Catheter-based cardiac mapping and catheter-based ablation are established diagnostic and therapeutic strategies for a range of arrhythmias. Many electrophysiology procedures are performed using minimally invasive surgical methods, where one or more instruments are inserted into the patient's body through one or more small incisions. The instruments can have a fixed or variable profile (e.g., a variable diameter loop). Mapping or imaging systems typically calculate metrics from EGM signals and provide a visual display of EGM metrics (color gradients) on the endocardial surface.

[0008] Regarding ablation, the instrument can also include a rigid or flexible component having an ablation device at or near its distal end, which is typically placed near the tissue to be ablated. The ablation device can deliver pulsed fields, radiofrequency, microwave energy, laser energy, extreme heat, and extreme cold to cause tissue necrosis. Catheter-based devices are very useful for a variety of medical and surgical applications because they are minimally invasive and allow precise treatment of local discrete tissues that are inaccessible by other means.

[0009] Catheter-based imaging (i.e., mapping) systems are well known in the field of cardiac electrophysiology. The OmniPolar Mapping technique (OT) makes it possible to reliably process the information underlying the heart rhythm. Specifically, OT is a signal processing method that more comprehensively utilizes the electrical signals from cardiac electrophysiology (EP) catheters. OT identifies the directional characteristics of intracardiac EGMs resolved by multi-electrode catheters and software algorithms, characterizing cardiac electrical activity in a way that is insensitive to catheter-wavefront direction. The resulting information is presented in a way that conforms to anatomical and physiological directions, rather than just from the perspective of the catheter.

[0010] Radiofrequency (RF)-based ablation systems are well known in the field of cardiac electrophysiology. In an RF ablation procedure, a specially designed probe is typically placed directly in the target area of the patient. Once doctors perform an EP diagnostic study, they insert a specially designed ablation catheter to apply radiofrequency energy to a specific area of interest within the patient's heart. Most ablation catheters are quadripolar, with a large distal tip that contains the mechanism for delivering RF energy to the heart. The RF energy can be delivered as alternating current, typically in the frequency range of 350 - 750 kilohertz (kHz), to accelerate electrons in cardiac cells - generating heat that destroys cells within a certain range of the catheter tip.

[0011] Like diagnostic catheters, ablation catheters come in many different types. These various types of catheters are designed to help doctors perform ablations at different locations on patients of different body sizes. Doctors typically select their preferred ablation catheter. However, challenging cases may prompt doctors to switch to other types of catheters. An ablation catheter delivers energy to the heart to destroy cells that may be causing the patient's arrhythmia. This is typically achieved using an RF generator. The energy from the generator is transmitted through a connecting cable to the ablation catheter, where it is concentrated at a specific site within the patient's heart. The goal is to form a small and delicate scar at the selected site. Once formed, the scar blocks the transmission of electrical signals through that area and hopefully terminates the arrhythmia.

[0012] When setting up the ablation system, temperature control or power control must be selected. Generally, doctors use temperature control, in which the desired temperature is selected and programmed into the generator. The maximum power and duration for a single ablation trial (also known as a "burn") are selected. Once all of these parameters are entered, the ablation process can begin.

[0013] Once the ablation catheter is activated, continuous readings of power display, temperature, impedance, and time are shown. The doctor must be continuously informed of the above value indicators. Once any significant change occurs in one of these parameters, the technician must immediately inform the doctor. In this way, any adverse effects during the ablation procedure can be avoided. Compared with open surgery, ablation surgery offers many advantages. Patients often cannot be treated by traditional surgery. In addition, when a patient has to undergo a second or more extensive surgery, it can be debilitating for the patient. Ablation can be performed multiple times on different occasions without the risks associated with surgery.

[0014] One type of ablation procedure is called pulsed field ablation (PFA), which is an emerging technology with potential advantages. Although early direct current (DC) shock therapies were abandoned due to safety concerns, it is known in the art that DC shocks provide irreversible electroporation (IRE). The mechanism by which damage is formed in IRE is that exposure to an electric field disrupts cell membrane permeability, leading to cell death. Pulsed field ablation is a form of IRE that uses (most commonly) bipolar and biphasic high-voltage and very short-duration pulse sequences that cause cell membrane instability (formation of pores in the cytoplasmic membrane) and cell death through the irreversible electroporation mechanism. This method has several potential advantages for arrhythmia ablation, including higher selectivity for myocardial tissue and smaller thermal effects, thus reducing the risk of inadvertently damaging blood vessels, nerves, and the esophagus.

[0015] As is well known, in the field of cardiac electrophysiology, PFA can produce transmural and persistent atrial lesions with minimal impact on the esophagus, phrenic nerve, and coronary arteries. Therefore, there is increasing interest in PFA as an alternative to RF ablation, especially for the treatment of atrial fibrillation. In known PFA ablation catheter designs, most are stand-alone ablation catheters that do not have mapping capabilities or integration with an electroanatomical mapping system.

[0016] Although different ablation methods have their respective advantages, in some cases, one method may be required over another. Additionally, during an ablation procedure, the situation can change rapidly, requiring the rapid replacement of an ablation catheter with a mapping catheter, another ablation catheter, and vice versa. There is currently no such system available that allows medical technicians to freely evaluate electrogram signals regardless of catheter orientation, select an ablation technique based on the patient's current medical condition, and perform sequential or simultaneous ablation procedures without the difficult, time-consuming, and laborious process of constantly replacing one type of catheter with another.

[0017] Therefore, considering the need to reduce the number of procedures and the need for precision in the ablation process, there is a need to provide an ablation system that allows for catheter orientation independence, wave velocity measurement and propagation direction, RF energy, cryoablation, and PFA. For example, cryoablation and RF ablation can be performed after real-time evaluation of a specific target tissue area; or cryoablation followed by PFA. There is also a need to provide an integrated ablation system that can accurately visualize the underlying mechanisms, especially when operating on difficult-to-access areas such as the atrioventricular (AV) node.

[0018] Some electrophysiology practitioners advocate the use of techniques that combine various modalities to overcome some of the drawbacks of individual treatment methods. The ability to apply treatment without removing the diagnostic catheter and then guessing where to place the ablation catheter has the potential to create a very flexible, safe, and efficient device that would greatly improve the workflow of physicians and reduce the time required to treat patients. Summary of the Invention

[0019] In one aspect, a catheter assembly is provided. The catheter assembly includes a tip electrode array including at least one tip electrode located at a distal end of the catheter assembly; and a microelectrode array including a plurality of microelectrodes located proximal to the tip electrode array, wherein each of the at least one tip electrode and each of the plurality of microelectrodes are configured to be independently activated from one another for mapping applications, and wherein at least some of the at least one tip electrode and the plurality of microelectrodes are configured to be synchronously activated for ablation applications.

[0020] In another aspect, an electroporation system is provided. The electroporation system includes a generator and a catheter coupled to the generator. The catheter includes a handle, a shaft extending distally from the handle, and a catheter assembly coupled to the distal end of the shaft. The catheter assembly includes: a tip electrode array including at least one tip electrode located at the distal end of the catheter assembly; and a microelectrode array including a plurality of microelectrodes disposed proximal to the tip electrode array. Each of the at least one tip electrodes and each of the plurality of microelectrodes are configured to be independently activated from each other for mapping applications, and at least some of the at least one tip electrodes and the plurality of microelectrodes are configured to be synchronously activated for ablation applications.

[0021] In another aspect, an ablation system is provided. The ablation system 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 via 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 via the hub, wherein the console is configured to selectively control the delivery of the first type of ablation energy and the second type of ablation energy to the at least one catheter via the hub.

[0022] The foregoing and other aspects, features, details, utilities, and advantages of the present disclosure will become apparent by reading the following description and claims and by viewing the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic and block diagram view of a system for electroporation therapy.

[0024] Figure 2 is a perspective view of one embodiment of a catheter assembly that can be used with the Figure 1 system shown.

[0025] Figure 3A is a perspective view of an alternative embodiment of a catheter assembly that can be used with the Figure 1 system shown.

[0026] Figure 3B is a perspective view of an alternative embodiment of a catheter assembly that can be used with the Figure 1 system shown.

[0027] Figure 3C is a perspective view of an alternative embodiment of a catheter assembly that can be used with the Figure 1Perspective view of an alternative embodiment of a catheter assembly for use with the system shown.

[0028] Figure 3D is an alternative embodiment of a catheter assembly that can be used with Figure 1 Perspective view of an alternative embodiment of a catheter assembly for use with the system shown.

[0029] Figure 3E is an alternative embodiment of a catheter assembly that can be used with Figure 1 Perspective view of an alternative embodiment of a catheter assembly for use with the system shown.

[0030] Figure 4A is an alternative embodiment of a catheter assembly that can be used with Figure 1 Perspective view of an alternative embodiment of a tip electrode array for use with the system shown.

[0031] Figure 4B is Figure 4A Exploded view of the tip electrode array shown.

[0032] Figure 5 is an alternative embodiment of a catheter assembly that can be used with Figure 1 Perspective view of an alternative embodiment of a catheter assembly for use with the system shown.

[0033] Figure 6A Schematic diagram of an embodiment of a flexible circuit architecture that can be used to implement the catheter assembly described herein.

[0034] Figure 6B Schematic diagram of another embodiment of a flexible circuit architecture that can be used to implement the catheter assembly described herein.

[0035] Figure 7 is an alternative embodiment of a catheter assembly that can be used with Figure 1 Schematic diagram of an alternative embodiment of a catheter assembly for use with the system shown.

[0036] Figure 8A and Figure 8B Schematic diagram of an embodiment of a mapping and ablation system.

[0037] Figure 9 is an alternative embodiment of a catheter assembly that can be used with Figure 8A and Figure 8B Schematic diagram of an embodiment of a catheter assembly for use with the system shown.

[0038] Figure 10A is an alternative embodiment of a catheter assembly that can be used with Figure 8A and Figure 8B Perspective view of an alternative embodiment of a catheter assembly for use with the system shown.

[0039] Figure 10B is Figure 10A End view of the catheter assembly shown.

[0040] Figure 7 is a schematic view of an alternative embodiment of a catheter assembly that can be used with the Figure 1 system shown.

[0041] Figure 11A is a Figure 1 side view of an alternative embodiment of a catheter assembly that can be used with the system shown.

[0042] Figure 11B is a Figure 11A perspective view of the tip electrode array of the catheter assembly shown.

[0043] Figure 12A and Figure 12B are perspective views of alternative embodiments of a catheter assembly that can be used with the Figure 1 system shown.

[0044] Figure 13 is a Figure 1 perspective view of an alternative embodiment of a catheter assembly that can be used with the system shown. DETAILED DESCRIPTION

[0045] Systems and methods for a catheter assembly are provided. The catheter assembly includes a tip electrode array that includes at least one tip electrode, the tip electrode array being located at a distal end of the catheter assembly; and a microelectrode array that includes a plurality of microelectrodes, the microelectrode array being disposed proximal to the tip electrode array, wherein each tip electrode of the at least one tip electrode and each microelectrode of the plurality of microelectrodes are configured to be activated independently of one another for mapping applications, and wherein at least some of the at least one tip electrode and the plurality of microelectrodes are configured to be activated synchronously for ablation applications.

[0046] Although at least some embodiments of the present disclosure are described with respect to pulmonary vein isolation (PVI), it is contemplated that, as will be appreciated by one of ordinary skill in the art based on the present disclosure, the features and methods of the present disclosure as described herein can be incorporated into any number of systems and any number of applications.

[0047] Figure 1 is a block diagram of a system 10 for electropermeabilization therapy. Generally, system 10 includes a catheter electrode assembly 12 disposed at a distal end 48 of a catheter 14. As used herein, "proximal" refers to the direction toward the end of the catheter closer to the clinician, and "distal" refers to the direction away from the clinician and (generally) within the patient. The electrode assembly includes one or more separate, electrically isolated electrode elements. Each electrode element (also referred to herein as a catheter electrode) is individually wired such that it can be selectively paired or combined with any other electrode element to act as a bipolar or multipolar electrode.

[0048] System 10 can be used for irreversible electroporation (IRE) to destroy tissue. Specifically, system 10 can be used for electroporation-induced primary apoptosis therapy, which refers to delivering an electric current in a manner that directly causes an irreversible loss of the integrity of the plasma membrane (cell wall), thereby resulting in its disruption and the effect of apoptosis. This mechanism of cell death can be regarded as an "outside-in" process, meaning that the disruption of the outer cell wall has an adverse effect on the interior of the cell. Generally, for classical plasma membrane electroporation, the electric current is delivered as a pulsed electric field between closely spaced electrodes in the form of short-duration pulses (e.g., having a duration of 0.1 to 20 milliseconds (ms)), capable of delivering an electric field strength of about 0.1 to 1.0 kilovolts per centimeter (kV / cm). System 10 can be used, for example, for high-output (e.g., high voltage and / or high current) electroporation procedures. In some specific embodiments, system 10 is configured to deliver an electroporation pulse signal having a relatively high voltage and a short pulse duration.

[0049] In one embodiment, all the electrodes of the catheter deliver current simultaneously. Alternatively, in other embodiments, excitation is delivered between electrode pairs on the catheter. Delivering current simultaneously using multiple electrodes can help create a damage deep enough for electroporation. To facilitate switching between i) simultaneously activating the electrodes to deliver energy and ii) activating the electrodes to sense signals (e.g., independently of each other), the electrodes can be switched between being connected to a 3D mapping system and being connected to an EP amplifier.

[0050] It should be understood that while the energization strategy is described as involving DC pulses, embodiments can use variations and remain within the spirit and scope of the present disclosure. For example, exponential decay pulses, exponential increase pulses, and combinations can be used. Additionally, in some embodiments, AC pulses can be used.

[0051] Furthermore, it should be understood that the mechanism of cell disruption in electroporation is not mainly due to heating effects, but rather the disruption of the cell membrane by applying a high-voltage electric field. Thus, electroporation can avoid some of the possible thermal effects that may occur when using radiofrequency (RF) energy. Therefore, this "cold therapy" has satisfactory characteristics.

[0052] Based on this background, and now referring again to Figure 1 , system 10 includes a catheter electrode assembly 12 that includes at least one catheter electrode. The electrode assembly 12 is incorporated as part of a medical device (e.g., catheter 14) for performing electroporation therapy on tissue 16 of a patient's body 17. In an exemplary embodiment, tissue 16 includes the heart or cardiac tissue. However, it should be understood that embodiments can be used for performing electroporation therapy on a variety of other body tissues.

[0053] Figure 1 Also shown are a plurality of return electrodes, labeled 18, 20, and 21, which are illustrations of body connections that can be used by various subsystems included in the overall system 10, such as electroporation generator 26, electrophysiology (EP) monitors (such as ECG monitor 28), and positioning and navigation system 30 for visualization, mapping, and navigation of internal body structures. In the illustrated embodiment, 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 these subsystems to which these patch electrodes are connected can and typically will include more than one patch (body surface) electrode and can include split patch electrodes (as described herein). In other embodiments, return electrodes 18, 20, and 21 can be any other type of electrode suitable for use as a return electrode, including, for example, one or more catheter electrodes. A return electrode that is a catheter electrode can be part of electrode assembly 12 or part of a separate catheter or device (not shown). System 10 can also include a main computer system 32 (including an electronic control unit 50 and a data memory 52), which in some embodiments can be integrated with the positioning and navigation system 30. System 32 can also include conventional interface components, such as various user input / output mechanisms 34A and a display 34B, as well as other components.

[0054] The electroporation generator 26 is configured to energize the electrode elements according to an electroporation energization strategy, which can be pre-determined or can be user-selectable. For electroporation-induced primary apoptosis therapy, the generator 26 can be configured to generate a current that is delivered as a pulsed electric field between closely spaced electrodes in the form of short-duration DC pulses (e.g., having a duration from 1 nanosecond to several milliseconds, a duration from 0.1 to 20 milliseconds, or any duration suitable for electroporation) through electrode assembly 12, capable of delivering an electric field strength of about 0.1 to 1.0 kV / cm (i.e., at the tissue site). The amplitude and pulse duration required for irreversible electroporation are inversely proportional. As the pulse duration decreases, the amplitude must increase to achieve electroporation.

[0055] The electroporation generator 26, sometimes also referred to herein as a DC energy source, is a single-phase electroporation generator 26 that is configured to generate a series of DC energy pulses, all of which produce current in the same direction. In other embodiments, the electroporation generator is a biphasic or polyphasic electroporation generator that is configured to produce DC energy pulses that do not all produce 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 fifty joules, one hundred joules, two hundred joules, etc. Other embodiments may have more or fewer energy settings, and the values of the available settings may be the same or different. For successful electroporation, some embodiments utilize an output level of two hundred joules. For example, the electroporation generator 26 can output DC pulses with peak amplitudes ranging from about 300 volts (V) to about 3,200 V at a two hundred joule output level. In some embodiments, the peak amplitude can be greater (e.g., around 10,000 V). Other embodiments can output any other suitable positive or negative voltage. For example, in some embodiments, the systems and methods described herein can include pulses with amplitudes ranging from about 500 V to about 4,000 V and pulse widths ranging from about 200 nanoseconds to about 20 microseconds.

[0056] In some embodiments, the variable impedance 27 allows the impedance of the system 10 to be changed to limit arcing. Additionally, the variable impedance 27 can be used to change one or more characteristics of the output of the electroporation generator 26, such as amplitude, duration, pulse shape, etc. Although shown as a separate component, the variable impedance 27 can be incorporated into the catheter 14 or the generator 26.

[0057] In other embodiments, one or more semiconductor devices in series with the catheter 14 can be used to limit arcing. For example, a specially designed semiconductor device modified from a field effect transistor can be implemented, which is a two-terminal device capable of very quickly acting to limit current and power. Two of these devices can be used for biphasic energy delivery, while one device can be used for single-phase energy delivery. Commercially available devices are designed for low current, generally in the milliamp range, but semiconductor devices for PFA applications can be designed by modifying the size and / or dopant concentration of existing devices. This will help improve patient safety and may enable the catheter and generator to be used multiple times.

[0058] Continuing to refer Figure 1 , as described above, the catheter 14 can include an electroporation function and, in certain embodiments, other types of ablation (e.g., RF ablation). However, it should be understood that in these embodiments, the type of ablation energy provided may vary (e.g., cryoablation, ultrasound, etc.).

[0059] In an exemplary 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 illustrated herein, such as temperature sensors, additional electrodes, and corresponding conductors or leads. The connector 40 provides a mechanical and electrical connection for a cable 56 extending from a generator 26. The connector 40 may include conventional components known in the art and is disposed at the proximal end of the catheter 14 as shown.

[0060] The handle 42 provides a location for a clinician to grip the catheter 14 and may also provide means for manipulating or guiding the shaft 44 within the body 17. For example, the handle 42 may include means for changing the length of a guide wire extending through the catheter 14 to the distal end 48 of the shaft 44 or for manipulating 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 should be understood that the construction of the handle 42 may vary. In an alternative embodiment, the catheter 14 may be driven or controlled by a robot. Thus, instead of a clinician manipulating the handle to advance / retract and / or manipulate or guide the catheter 14 (and in particular 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 may contain additional electronics for signal processing or conditioning. The shaft 44 may also permit the transport, delivery, and / or removal of fluids (including flushing fluids and body fluids), drugs, and / or surgical tools or instruments. The shaft 44 may be made of 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. The shaft 44 may be introduced into a blood vessel or other structure within the body 17 through a conventional introducer. The shaft 44 may then be advanced / retracted and / or manipulated or guided through the body 17 to a desired location, such as a site of tissue 16, including by using a guide wire or other devices known in the art.

[0061] In some embodiments, the catheter 14 includes a basket catheter assembly having catheter electrodes distributed in a basket configuration at the distal end of the shaft 44 ( Figure 1 not shown). Additionally, as described herein, an inflatable balloon may be accommodated within the basket configuration.

[0062] A positioning and navigation system 30 can be provided for visualization, mapping, and navigation of internal body structures. The positioning and navigation system 30 can include conventional devices commonly known in the art (e.g., the EnSite Precision™ system available from Abbott Laboratories. And as generally shown in the co-owned U.S. Patent No. 7,263,397 entitled “Method and Apparatus for Catheter Navigation and Location and Mapping in the Heart,” the entire disclosure of which is incorporated herein by reference). However, it should be understood that this system is merely an example and is not restrictive in nature. Other techniques for positioning / navigating a catheter (and for visualization) in space are known, including, for example, the CARTO navigation and positioning system of Biosense Webster, Inc., the Rhythmia® system of Boston Scientific Scimed, Inc., the KODEX® system of Koninklijke Philips N.V., the AURORA® system of Northern Digital Inc., conventional fluoroscopy systems, or magnetic positioning systems (e.g., the gMPS system of Mediguide Ltd.). In this regard, some positioning, navigation, and / or visualization systems will involve providing sensors for generating signals indicative of catheter position information and can include, for example, one or more electrodes in the case of an impedance-based positioning system, or alternatively, one or more coils (i.e., coil windings) configured to detect one or more characteristics of a magnetic field in the case of, for example, a magnetic-field-based positioning system. As another example, the system 10 can utilize a combined system based on electric fields and magnetic fields, as generally shown in U.S. Patent No. 7,536,218 entitled “Hybrid Magnetic-Based and Impedance Based Position Sensing,” the disclosure of which is incorporated herein by reference in its entirety.

[0063] Pulsed field ablation (PFA) has been shown to be an effective ablation modality for treating arrhythmias, particularly for transient pulmonary vein isolation (PVI). PFA involves delivering high-voltage pulses from electrodes disposed on a catheter (e.g., including the basket and / or balloon catheters described herein). For example, in PFA, the voltage amplitude range can be from about 300 V to at least 3,200 V (or even up to about 10,000 V), and the pulse width can range from hundreds of nanoseconds to tens of milliseconds.

[0064] These electric fields can be applied between adjacent electrodes (using a bipolar approach) or between one or more electrodes and a return patch (using a unipolar approach).

[0065] Both approaches, using appropriate electrode geometries and catheter placement, can provide continuous lesions. For lesion size and proximity, the unipolar approach can produce deeper lesions at the same applied voltage. Additionally, the unipolar approach can be capable of creating lesions from a distance (e.g., typically close to, but not necessarily in contact with, the tissue). The bipolar approach can create smaller lesions, which require closer proximity to or contact with the tissue to create a transmural lesion.

[0066] To monitor the operation of system 10, one or more impedances between catheter electrodes and / or return electrodes 18, 20, and 21 can be measured. For example, for system 10, impedances can be measured as described in U.S. Patent Application Publication No. 2019 / 0117113, filed on October 23, 2018, U.S. Patent Application Publication No. 2019 / 0183378, filed on December 19, 2018, and U.S. Patent Application No. 63 / 027,660, filed on May 20, 2020, all of which are incorporated herein by reference in their entirety.

[0067] Embodiments disclosed herein include catheters capable of performing mapping and ablation functions. Generally, embodiments disclosed herein include catheters having an increased (compared to at least some known systems) electrode density at the tip and distal portion. This enables higher resolution, which in turn improves the system's ability to define and localize arrhythmia characteristics.

[0068] Embodiments described herein enable higher resolution mapping, generate higher fidelity electrograms (EGMs), and improve the signal-to-noise ratio (SNR). Higher resolution mapping results in improved mapping of boundaries / edges (e.g., the edges of scar tissue). These embodiments also provide improved techniques for detecting contact between the catheter and the patient's tissue. Additionally, embodiments described herein provide full-pole mapping techniques (OT) in two and three dimensions for the catheter body. Moreover, these embodiments can reduce the cost of manufacturing catheter assemblies.

[0069] The catheter assemblies described herein include various electrode arrangements. The electrodes can be operated independently of each other (in a "non-linked" configuration) or can function together as a larger effective electrode (in a "linked" configuration). For example, when operated independently of each other, the electrodes can be used for mapping applications and / or EGM applications. Conversely, multiple electrodes can be connected together to be used as a composite electrode for ablation applications and / or near-field impedance navigation applications. Additionally, different subsets of electrodes can be selectively activated (relative to each other) to provide improved control of ablation procedures.

[0070] As explained in detail below, the present disclosure provides catheter designs (e.g., linear, circular, basket-shaped) that allow for cardiac mapping (particularly OT) and ablation without the need for separate catheters for mapping and ablation or separate catheters for different ablation modalities.

[0071] If the local electrical activity of the region can be mapped prior to ablation - especially when using OT and mapping visualization tools to confirm the true presence of the arrhythmia source - then the treatment of arrhythmias by selective ablation of cardiac tissue can be improved. This enables the almost immediate treatment of the arrhythmia source without the need to remove the diagnostic catheter and insert an ablation catheter. This is particularly important because after removing the diagnostic catheter and then inserting an ablation catheter that may not support similar mapping techniques or electrode configurations, it is often not possible to localize the region or rhythm.

[0072] At least some of the embodiments described herein provide multi-modal ablation systems and hybrid catheter designs having microelectrodes arranged in an array (e.g., in a square array) configured to accommodate OT. Additionally, the microelectrodes can be used to configure local tissue resistance load measurements. Such measurements provide an improved assessment of the contact between the tissue and the catheter.

[0073] The ablation assembly is capable of delivering energy to the tissue and / or removing heat from the tissue. In at least some embodiments, the mapping assembly is capable of generating one or more different maps. The OT assembly uses, for example, the microelectrode array on the hybrid catheter design provided herein.

[0074] The present disclosure also provides a processor that can selectively control the delivery of one or more different forms of therapeutic energy and selectively activate and control 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 that is capable of providing one or more different forms of therapeutic energy to one or more energy treatment devices coupled to the therapeutic energy generation station. Then selectively providing the therapeutic energy to the one or more energy treatment devices. Ablating the target tissue region using the one or more energy treatment devices.

[0075] Accordingly, a hybrid catheter with microelectrodes is provided that allows for PT and local impedance estimation. In addition, a multi-mode ablation system capable of delivering various energy types (such as cryoablation, microwave ablation, PFA, RF) is provided, as well as a system that allows for selective control and utilization of the catheter to perform various ablation strategies. While cardiac-based OT mapping, RF ablation, PFA, microwave ablation, cryoablation, and other ablation techniques are all useful, it has become inconvenient, ineffective, and expensive to remove and replace existing catheters to effectively map and ablate tissue regions using different forms of ablation. In addition, doctors have pointed out that it may be difficult to obtain the same signal or view of the arrhythmia when a grid catheter (e.g., Advisor™ HD grid mapping catheter or Sensor Enabled™ (SE) mapping catheter) that provides excellent electrogram characteristics and has an OT function is moved away from the site of interest. As a result, it has become very difficult to perform ablation procedures precisely as desired. The ablation system of the present disclosure provides a unique catheter design to allow for OT mapping and the ability to interact with all existing catheters of the design to effectively treat tissue treatment regions.

[0076] Figure 2 is a perspective view of one embodiment of a catheter assembly 200 that can be used with system 10 ( Figure 1 shown in). For example, catheter assembly 200 can be implemented as part of catheter 14. Catheter assembly 200 includes a tip electrode array 202, a microelectrode array 204, and a plurality of annular electrodes 206. In this embodiment, annular electrodes 206 are located proximal to microelectrode array 204, and tip electrode array 202 is distal to microelectrode array 204.

[0077] As Figure 2 shown, tip electrode array 202 includes a plurality of tip electrodes 208 separated by non-conductive segments 209. Specifically, tip electrode array 202 includes four tip electrodes 208 separated by four non-conductive segments 209. Tip electrode array 202 also has a dome shape.

[0078] In Figure 2 the embodiment, microelectrode array 204 includes a plurality of rectangular electrodes 210 wound around the circumference of catheter assembly 200. In addition, rectangular electrodes 210 are arranged in a brick pattern on a non-conductive substrate 212 that insulates rectangular electrodes 210 from each other.

[0079] For mapping applications, the tip electrode 208 and the rectangular electrode 210 can function or be activated independently of each other (i.e., can sense voltage independently of each other, be energized independently of each other, can be energized with different polarities with respect to each other, and / or can be energized with different voltages with respect to each other). For example, using the tip electrode 208 and the rectangular electrode 210 to sense voltage independently of each other helps obtain navigation impedance information that can be used to accurately display the catheter and generate independent electrograms.

[0080] Conversely, for ablation applications, two or more tip electrodes 208 and rectangular electrodes 204 are activated synchronously to form a larger effective electrode. For example, if all the rectangular electrodes 204 are activated synchronously, they function effectively as a ring electrode (similar to the ring electrode 206). Those skilled in the art will understand that any suitable combination of electrodes can be activated synchronously.

[0081] Figure 2 is an example of a catheter assembly including a tip electrode array and a microelectrode array. Those skilled in the art will understand that many other configurations are possible. For example, Figures 3A - 3E is a perspective view of an optional catheter assembly.

[0082] Figure 3A illustrates a catheter assembly 302 that includes a tip electrode array 304 and a microelectrode array 306. The tip electrode array 304 includes a plurality of tip electrodes 308 separated by non-conductive segments 310. Here, the tip electrode array 304 also has a flat shape (opposite to the dome-shaped shaft of the tip electrode array 202 ( Figure 2 shown)).

[0083] In Figure 3A 's embodiment, the microelectrode array 306 includes a plurality of rectangular electrodes 312 wound around the circumference of the catheter assembly 302. In addition, the rectangular electrodes 312 are arranged in a brick-like pattern on a non-conductive substrate 314 that insulates the rectangular electrodes 312 from each other.

[0084] Figure 3B illustrates a catheter assembly 322 that includes a tip electrode array 324 and a microelectrode array 326. The tip electrode array 324 includes a plurality of tip electrodes 328 separated by non-conductive segments 330. Here, the tip electrode array 324 has a flat shape.

[0085] In Figure 3B 's embodiment, the microelectrode array 326 includes a plurality of circular electrodes 332 arranged around the circumference of the catheter assembly 322. In addition, the circular electrodes 332 are arranged in a spaced-apart pattern on a non-conductive substrate 334 that insulates the circular electrodes 332 from each other.

[0086] Figure 3CA catheter assembly 342 is shown, which includes a tip electrode array 344 and a microelectrode array 346. The tip electrode array 344 includes a plurality of tip electrodes 348 separated by non-conductive segments 350. Here, the tip electrode array 344 has a flat shape.

[0087] In Figure 3C the embodiment of, the microelectrode array 346 includes a plurality of circular electrodes 352 arranged around the circumference of the catheter assembly 342. In addition, the circular electrodes 352 are arranged in a spaced-apart pattern on a non-conductive substrate 354 that insulates the circular electrodes 352 from each other.

[0088] Figure 3D A catheter assembly 362 is shown, which includes a tip electrode array 364 and a microelectrode array 366. The tip electrode array 364 includes a plurality of tip electrodes 368 separated by non-conductive segments 370. Here, the tip electrode array 364 has a dome shape.

[0089] In Figure 3D the embodiment of, the microelectrode array 366 includes a plurality of circular electrodes 372 arranged around the circumference of the catheter assembly 362. In addition, the circular electrodes 372 are arranged in a spaced-apart pattern. In this embodiment, an annular electrode 373 extends around the catheter assembly 362, and the circular electrodes 372 are placed within the holes 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 an ablation application, the circular electrodes 372 and the annular electrode 373 can be activated synchronously to function as a ring electrode.

[0090] Figure 3E A catheter assembly 382 is shown, which includes a tip electrode array 384 and a microelectrode array 386. The tip electrode array 384 includes a plurality of tip electrodes 388 separated by non-conductive segments 390. Here, the tip electrode array 384 has a flat shape.

[0091] In Figure 3E the embodiment of, the microelectrode array 386 includes a plurality of circular electrodes 392 arranged around the circumference of the catheter assembly 382. In addition, the circular electrodes 392 are arranged in a spaced-apart pattern. In this embodiment, an annular electrode 393 extends around the catheter assembly 382, and the circular electrodes 392 are placed within the holes 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 an ablation application, the circular electrodes 392 and the annular electrode 393 can be activated synchronously to function as a ring electrode.

[0092] Figure 4A is a perspective view of another embodiment of the tip electrode array 400, and Figure 4Bis an exploded view of the tip electrode array 400. The tip electrode array 400 includes a plurality of 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 Figure 4B best shown in, in this embodiment, the non-conductive segments 406 are formed by a single non-conductive insert 408 inserted between the four tip electrodes 404.

[0093] Figure 5 is a perspective view of another embodiment of the catheter assembly 500. The catheter assembly 500 includes a tip electrode array 502 and a microelectrode array 504. The tip electrode array 502 includes a plurality of circular tip electrodes 506 arranged in a grid. In addition, the microelectrode array 504 includes a plurality of circular electrodes 508 arranged in a grid around the circumference of the catheter assembly 500. The circular tip electrodes 506 and the circular electrodes 508 are placed in holes defined within a substrate 510. In some embodiments, the substrate 510 is conductive (and can be activated synchronously with the circular tip electrodes 506 and / or the circular electrodes 508 for ablation applications), while in other embodiments, the substrate 510 is non-conductive.

[0094] Figure 6A is a schematic diagram of one embodiment of a flexible circuit architecture 600 that can be used to implement the catheter assemblies described herein. The flexible circuit architecture 600 can be used to, for example, implement Figures 2 - 5 the microelectrode arrays shown in. Those skilled in the art will understand that the flexible circuit architecture 600 can be wound into an annular shape to form those microelectrode arrays.

[0095] The flexible circuit architecture 600 includes a substrate 602 having an outer surface 604. A plurality of electrodes 606 (e.g., platinum / iridium (Pt / Ir) electrodes) are placed on the outer surface 604. Leads 608 for providing energy to the electrodes 606 extend through the substrate 602 and are connected to the back sides of the electrodes 606.

[0096] Figure 6B is a schematic diagram of an alternative embodiment of a flexible circuit architecture 620 that can be used to implement the catheter assemblies described herein. The flexible circuit architecture 620 can be used to, for example, implement Figures 2 - 5 the microelectrode arrays shown in. Those skilled in the art will understand that the flexible circuit architecture 620 can be wound into an annular shape to form those microelectrode arrays.

[0097] The flexible circuit architecture 620 includes a substrate 622 having an outer surface 624. Here, in contrast to the flexible circuit architecture 600, a plurality of electrodes 626 are embedded below the outer surface 624. Further, a wiring 628 for supplying energy to the electrodes 626 is connected to the outer surface of a pad 630 (e.g., a Pt / Ir pad), and the pad 630 is in turn electrically connected to one or more electrodes 626.

[0098] Figure 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 microelectrode array 704, a second microelectrode array 706, and an annular electrode 708. The tip electrode array 702 includes a first tip electrode 710 and a second tip electrode 712. The first microelectrode array 704 includes a plurality of circular electrodes 720 and a conductive substrate 722, and the second microelectrode 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 example configuration of electrodes, and other electrode arrangements are within the spirit and scope of the present disclosure.

[0099] Figure 7 Illustrated are electric field lines 750, which represent the electric field generated when the first and second tip electrodes 710 and 712 are used in a bipolar configuration (i.e., a voltage is generated between the first and second tip electrodes 710 and 712). Those skilled in the art will understand that any suitable pair of electrodes in the tip electrode array 702, the first microelectrode array 704, the second microelectrode array 706, and / or the annular electrode 708 can be used in a bipolar configuration.

[0100] Figure 8A is a schematic diagram of an embodiment of a mapping and ablation system 800. The system 800 is capable of performing RF ablation and PFA, as well as other ablation types (e.g., microwave ablation and cryoablation). The system 800 includes a console 802, a catheter 804, and a cable system 803 that couples the console 802 to the catheter 804.

[0101] The catheter 804 can be, for example, a linear catheter, a circular catheter, and / or any other suitable energy treatment device that can be easily and smoothly moved through blood vessels and heart valves. The cable system 803 includes electrical signal lines for monitoring and / or mapping tissue and heart regions, and can be coupled to a mapping system 807 and an ECG / electrogram monitor 808. In this embodiment, the cable system 803 includes a cooling injection cable system 810 and a vacuum cable system 812, which provide an inlet and a return path, respectively, for a coolant for cooling the tissue treatment end of the catheter 804.

[0102] The console 802 provides a user interface for the system 800 and houses electronic devices and software for controlling and recording mapping and ablation procedures, controlling the delivery of a liquid coolant under pressure through the cable system 803 to the catheter 804, controlling the recovery of the expanded refrigerant vapor from the catheter 804 under vacuum, and controlling a compressor to pressurize the coolant vapor into a liquid stored in a recovery tank. In addition to the liquid coolant, auxiliary heat removal or dissipation elements, such as conductive coils, can also be used.

[0103] The system 800 generates a controlled temperature and / or pulse at the tip of the catheter 804. One or more selected catheters 804 can be coupled to the console 802. For example, Figure 8B The system 800 with two catheters 804 connected is shown. Generally, the catheter 804 is long enough and flexible enough to be inserted into various body ducts. The system 800 can be used with catheters designed for intravascular and open surgical procedures. The system 800 is configured to supply more than one type of energy to the catheter 800 (e.g., the system 800 can be used with a catheter 804 capable of being applicable to PFA, RF ablation, cold tip RF ablation, microwave ablation, cryoablation, and / or mapping procedures, especially OT). At least one of the catheters 804 can be a focused tip catheter that generates a concentrated tissue destruction (i.e., ablation) area, a linear catheter that delivers cooling along the length of the catheter, or a circular catheter suitable for PVI isolation.

[0104] In Figure 8A and 8B the illustrated embodiment, the radio frequency generator 820 is coupled to the generator hub 822. Using the controls on the console 2, the user can select the type of ablation procedure he or she wishes to perform.

[0105] The catheter 804 can include one or more electrodes around it. If the user wishes to perform an RF ablation procedure, as is common in the state of the art in the field of cardiac ablation, radio frequency energy can be provided to the electrodes of the catheter 804 via the cable system 803 to perform RF ablation techniques. Specifically, the RF energy is provided between the electrodes located on or within the catheter 804 and the non-polar electrode 824 (also known as the indifferent electrode). The non-polar electrode 824 can be placed, for example, on the patient's body. The RF energy flows through the patient tissue between the electrodes on the catheter 804 and the non-polar electrode 824, causing cell death of the target tissue or treating the target tissue.

[0106] In some embodiments, a conductive coolant can be delivered to the catheter 804 alone or simultaneously with the delivery of the RF current to complete the electrical connection to the electrodes. DC (direct current) can also be supplied to the catheter 804.

[0107] The underlying mechanism of damage formation by DC electroshock is known in the field of electrophysiology and results in irreversible electroporation (IRE). Damage formation in IRE is the effect of the disruption of cell membrane permeability and homeostasis by exposure to an electric field. This leads to cell death while maintaining the integrity and function of nearby structures such as the esophagus, lungs, coronary arteries, PV, and phrenic nerve.

[0108] As described above, PFA is a form of IRE that uses high voltage and short-duration single-phase or biphasic pulse sequences to cause cell death in tissue without significant heating (when waveform parameters are appropriately optimized). The tissue effect at the target location is directly controlled by the amplitude and duration of the applied electric field. Voltage directly affects the electric field intensity distribution; that is, an increase in voltage will result in an increase in treatment intensity. When the voltage amplitude increases, tissue heating increases, muscle may contract, and a certain amount of gaseous microemboli (i.e., microbubbles) may be generated.

[0109] For PFA, when multiple pulses are delivered in a rapid succession (e.g., within a time scale of nanoseconds to milliseconds), their effects can be considered as a collective pulse, called a packet. When multiple packets are delivered to the tissue, the cumulative damage to the cells increases. Thus, more packets will result in a stronger treatment effect but will increase the treatment delivery time (for a matched packet delivery rate), and the cumulative temperature rise will increase if the time for heat dissipation between subsequent packets is insufficient. When a pause is provided between the pulse sequence or packets, the tissue has the opportunity to conduct heat away from the heated tissue and thus reduce the total temperature rise. When the pulse sequence is delivered with a relatively long pause (milliseconds to tens of seconds), cell recovery is generally not affected, but the total tissue temperature rise is reduced. This enables the delivery of a powerful cumulative treatment while maintaining an acceptable level of temperature rise.

[0110] As Figure 8B shown, in addition to the RF generator 820, a PFA generator 830 can also be coupled to the hub 822. PFA energy can also be delivered to the patient through the catheter 804. Those skilled in the art will understand that in other embodiments, other energy sources (e.g., cryoablation generators) can be selectively coupled to the hub 822.

[0111] Thus, the system 800 allows for the delivery of various combinations of different types of ablation energy to one or more catheters 804 in the ablation target tissue region. Ablation procedures can be performed sequentially, depending on the desired treatment strategy for treating the tissue. The possibility of quickly switching from one ablation procedure to another can lead to better treatment outcomes for tissue damage.

[0112] For example, in a scenario where a doctor desires to achieve deep tissue damage, cryoablation can first be performed on the tissue for 45 seconds until local edema is caused. Then, radiofrequency ablation can be performed after extracellular fluid has accumulated near the tissue area to allow RF energy to more easily diffuse deeper into the tissue area.

[0113] In another example, a target tissue area near the esophagus is mapped in combination with OT. For this purpose, for example, a superficial lesion with a depth of 1 - 3 mm is sufficient to complete isolation. Then PFA is used alone, and the field strength set by the user is approximately 300 V / cm.

[0114] In another example, assume that a doctor desires to apply PFA within a closed area. Cryoablation can be performed first. Notably, when PFA is subsequently applied to the cryogenic ice created by cryoablation, it is confined within the ice. This makes it possible to directly visualize the ablation area using conventional imaging techniques.

[0115] Figure 9 is an embodiment of a catheter assembly 900 that can be used with system 800 (as Figure 8A and 8B shown) or system 10 (as Figure 1 shown). The catheter assembly 900 is a linear assembly that includes a plurality of annular electrodes 902. Additionally, for at least some of the annular electrodes 902, a microelectrode array 904 is formed around the annular electrode 902. In this embodiment, each microelectrode array 904 includes four microelectrodes 906 arranged in a square grid pattern, where the microelectrodes 906 are evenly spaced from each other. Although one microelectrode array 904 is shown on each annular electrode 902, in some embodiments, more than one microelectrode array 902 can be included on a single annular electrode 904.

[0116] The microelectrode array 904 can be used for applications that customize electrical energy (e.g., generating a full-pole mode and / or directing the application of pacing, RF, or PFA energy). Additionally, the microelectrode array 904 takes advantage of OT and is capable of sensing a consistent voltage signal regardless of direction and of detecting the wave propagation speed and direction. Specifically, the square arrangement of the microelectrode array 904 supports OT mapping techniques, and the microelectrode array 904 can be used in a variety of catheter designs (e.g., linear or circular catheters). Using a mapping system, the grid arrangement of the microelectrode array 904 can display directional characteristics, propagation speed, and / or maximum voltage electrograms regardless of the catheter direction. Additionally, using the microelectrode array 904, the impedance load at the tissue-catheter interface can be measured locally, providing a better differentiation between the myocardium and the blood pool. The impedance load on the distal electrode of an ablation catheter is largely affected by the ratio of the surface areas covered by myocardium and blood. The myocardium impedance is greater than the blood pool impedance (e.g., 3.0–6.0 ohm-meters (Ω-m) and 1.5 Ω-m, respectively). Notably, the increase in myocardial resistivity when compared to blood is the reason for its tendency to joule heat.

[0117] Several techniques have attempted to measure the resistive load at the catheter-tissue interface through impedance. Traditionally, RF generators estimate the resistive load through the thoracic impedance of the energy delivery path from the tip electrode of the ablation catheter to a non-polar electrode on the skin. Although RF generators can reasonably estimate the impedance difference between tissue and blood, they are hindered by large variations in the body impedance of the torso (such as muscle, lung, and bone).

[0118] In contrast, using the embodiments described herein, the microelectrode array 904 incorporated with the larger annular electrode 902 can be used to measure the resistive load more locally. For example, a non-exciting AC current can be driven between the distal and proximal electrodes of a linear ablation catheter, generating a local potential field. Then, the microelectrode 906 can be used to measure the changes in the potential field that may be caused by nearby heart tissue. The measured potential can be converted to impedance by dividing by the injected current.

[0119] It is well known that catheter impedance stabilizes before reaching an unsafe contact force. Therefore, local impedance measurements on an ablation catheter can serve as a surrogate indicator of the surface area of the distal electrode covered by myocardium. Although contact force can provide a safety advantage, the value of the force does not reliably predict catheter-tissue surface area coverage and resistive heating during RF applications. For example, a catheter gently placed in the trabeculae can have a low contact force, but because the distal electrode is covered by tissue, it can still deliver a large amount of RF energy to the myocardium.

[0120] Figure 10A can be with system 800 such as Figure 8A and 8BPerspective view of one embodiment of a catheter assembly 1000 for use with (shown). Figure 10B is an end view of the catheter assembly 1000. As Figure 10A and 10B shown, the catheter assembly 1000 is an annular assembly. The catheter assembly 1000 includes a plurality of annular electrodes 1002. In addition, for at least some of the annular electrodes 1002, a microelectrode array 1004 (see enlarged portion) is formed on the annular electrode 1002. In this embodiment, each microelectrode array 1004 includes four microelectrodes 1006 arranged in a square grid pattern, where the microelectrodes 1006 are evenly spaced from each other. Although one microelectrode array 1004 is shown on each annular electrode 1002, in some embodiments, more than one microelectrode array 1002 may be included on a single annular electrode 1004. The function of the microelectrode array 1004 is substantially similar to that of the microelectrode array 904 (as Figure 9 shown).

[0121] In the present embodiment, the catheter assembly 1000 includes nine annular 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 in the same plane as the outer electrodes. In addition, in some embodiments, the catheter assembly 100 includes two central electrodes: one in the same plane as the outer electrodes and one outside of this plane.

[0122] Alternatively, the catheter assembly 1000 may include any suitable number of annular electrodes 1002. The catheter assembly 1000 can be used for pulmonary vein ablation. It can be powered by a duty cycle radiofrequency (RF) generator or a specially designed PFA generator. The catheter assembly 100 can effectively create a continuous transmural lesion capable of isolating the PV. In addition, it is possible to deliver pulsed electric field energy through the catheter assembly 1000, and continuous transmural myocardial lesions can be created, just like RF energy. The PFA energy design can be configured to connect the electrodes 1002 “D”, “3”, “5” and “7” as one polarity and the electrodes 1002 “2”, “4”, “6” and “8” as the opposite polarity via a cable to deliver a high-voltage bipolar pulse sequence to the catheter assembly 1000. The duty cycle RF energy can be delivered in a bipolar / monopolar ratio of 2:1, with a maximum power of 10 watts (W) per electrode and a temperature set point of 60 degrees Celsius for 60 seconds at each placement location. The PF energy can be delivered as a biphasic pulse sequence with a pulse width of 100 microseconds (µs) for each phase and an interpulse interval of 200 µs. Those skilled in the art will understand that these parameters are merely examples of possible parameters.

[0123] In an electroanatomical mapping scenario, a user applies a set of mapping configurations through a menu on a monitor 808 (shown in FIG. 8). Specifically, the monitor 808 can be used to select various mapping types to survey electrograms of interest on the display. Since the spacing between the microelectrodes is relatively small, typically only local information is provided to the doctor. However, a circular catheter, such as the catheter assembly 1000, can be configured to provide a local view and a larger view of the target area.

[0124] Review Figure 8A and 8B The catheter 804 can be any suitable RF ablation, PFA, microwave ablation, and / or cryoablation catheter, as well as a hybrid catheter having the ability to ablate tissue through a combination of PFA, RF, microwave ablation, and cryoablation. A computing device (e.g., included in the console 802) allows the user to selectively control which catheter 804 will receive the selected energy type. The user can, for example, choose to treat the target tissue using a conventional RF procedure. Additionally, mapping can be performed prior to the ablation procedure.

[0125] Alternatively, the user can choose to treat the target tissue using a PFA procedure. Then, the computing device is instructed to access the catheter 804 capable of performing PF that has been coupled to the system through the cable system 3. Prior to the PFA creating lesions, electroanatomical mapping can be performed first. This can be achieved by first enabling the desired catheter 804 for mapping the desired region. Any combination of ablation procedures can be used to treat the target tissue by first enabling a compatible cryotherapy catheter, microwave catheter, RF ablation catheter, or PFA catheter. Additionally, the same catheter can be used immediately following ablation to evaluate the effectiveness of the treatment application by remapping. In this way, multiple mappings and a wide range of temperatures can be achieved without changing and / or replacing one type of catheter with another type of catheter 804.

[0126] Using the embodiments described herein, any desired combination of ablation procedures can be performed on the target tissue area. For example, mapping procedures can be performed or not performed prior to ablation. Additionally, ablation procedures can be performed in any suitable order. For example, RF ablation can be performed first, followed by PFA, especially in areas near a circulating "heat sink" such as a blood vessel known to limit lesion formation using conventional ablation techniques.

[0127] Multi-mode procedures can also be implemented, where the order of the ablation procedures is programmed and automatically controlled by the computing device. Specifically, the user provides inputs to the computing device, and these inputs result in activation signals to the appropriate catheter 804 to control the type of energy delivered, as well as auxiliary functions such as circulating coolant to the catheter 804.

[0128] Using the embodiments described herein, RF ablation, PFA, microwave ablation, and / or cryoablation can also be performed simultaneously. That is, different types and amounts of ablation energy can be delivered to the catheter 804 to perform ablation procedures simultaneously. For example, in a multi-catheter scenario, one catheter 804 can receive coolant for a cryoablation procedure, while RF energy can be provided to another catheter 804 via the RF generator 820, and PFA energy can be provided to yet another catheter 804. Additionally, microwave energy can be applied to yet another catheter 804.

[0129] The embodiments described herein are not limited to a particular number of catheters or a particular order of ablation sequences. The multi-energy ablation systems described herein allow for a variety of different types of probes or catheters, each of which is capable of performing one or more ablation procedures and is coupled to a control system that selectively provides the various types of energy required for mapping and ablating body regions. Such systems would be very helpful to practitioners of cardiac electrophysiology, especially since these systems can overcome the drawbacks of various ablation modes in at least some known systems.

[0130] Figure 11A is a side view of another embodiment of a catheter assembly 1100 that can be used with the systems and methods described herein (e.g., Figure 1 the system 10 shown, or Figure 8A and 8B the system 800 shown). For example, the catheter assembly 1100 can be implemented as part of a catheter 14. The catheter assembly 1100 includes a tip electrode array 1102 and a plurality of annular electrodes 1106. Figure 11B is a perspective view of the tip electrode array 1102.

[0131] As Figure 11A and 11B shown, 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 segments 1109 can be formed by a single non-conductive insert (similar to the non-conductive insert 408 (as Figure 4B shown)).

[0132] The shape of the tip electrode array 1102 is such that the catheter assembly 1100 can create a relatively uniform lesion regardless of the contact angle between the catheter assembly 1100 and the patient tissue. That is, the use of the catheter assembly 1100 prevents or significantly reduces the creation of shadow lesions (e.g., lesions inadvertently created during treatment). The tip electrode array 1102 can have any suitable size. For example, in some embodiments, the spherical portion of the tip electrode array 1102 has a diameter of about 4.19 mm, 3.94 mm, or 2.34 mm.

[0133] The relatively large diameter of the tip electrode array 1102 can also have other advantages. For example, a larger diameter will necessarily reduce the rate of local field strength decay, which means a more uniform RF and PFA effect radius.

[0134] Figure 12A is a perspective view of another embodiment of a catheter assembly 1200 that can be used with the systems and methods described herein (e.g., Figure 1 the system 10 shown). For example, the catheter assembly 1200 can be implemented as part of a catheter 14. The catheter assembly 1200 includes a tip electrode array 1202 and a ring electrode 1204. Figure 12B is another perspective view of the catheter assembly 1200.

[0135] As Figure 12A and 12B shown, the tip electrode array 1202 includes a basket 1210 that has a plurality of conductive splines 1212 that serve as electrodes. The basket 1210 can have a diameter of, for example, about 1 centimeter (cm). In some embodiments, a pulling member (e.g., a pull ring and / or a pull wire) can be used to selectively increase the diameter of the basket 1210 (e.g., increase by about 0.152 mm). The splines 1212 can serve as electrodes independent of each other or can be activated synchronously. Similar to the catheter assembly 1100 ( Figure 11A and 11B shown), the shape of the tip electrode array 1202 is such that the catheter assembly 1200 can create a relatively uniform lesion regardless of the contact angle between the catheter assembly 1200 and the patient tissue. Additionally, applying energy between a tip electrode (e.g., Figure 11A the electrode 1108 in Figure 11A and the shaft electrode closest to that tip electrode (e.g.,

[0136] the leftmost ring electrode 1106 in Figure 12A and 12B also helps reduce the effect of the contact angle on the shape of the lesion. Figure 13is a perspective view of another embodiment of a catheter assembly 1300 that can be used with the systems and methods described herein (e.g., Figure 1 the system 10 shown). The catheter assembly 1300 includes a tip electrode array 1302 and a ring electrode 1304.

[0137] As Figure 13 shown, the tip electrode array 1302 includes a basket 1310 having a plurality of splines 1312, each spline including one or more electrodes. The basket 1310 can have a diameter of, for example, about 1 centimeter (cm). In some embodiments, a pulling member (e.g., a pull ring and / or a pull wire) can be used to selectively increase the diameter of the basket 1310 (e.g., increase by about 0.152 mm).

[0138] In this embodiment, the first spline 1320 includes a plurality of ring electrodes 1322. Additionally, the second spline 1330 includes an elongate flexible strut electrode 1332 and a plurality of flexible point electrodes 1334. As shown, the flexible point electrodes 1334 are smaller than the flexible strut electrode 1332. In this embodiment, the tip electrode array 1302 further includes a discrete tip electrode 1340 having four selectively activatable (e.g., synchronous or independent of each other) quadrant electrodes 1342. Alternatively, the tip electrode array 1302 can include one or more electrodes in any suitable arrangement. For example, in some embodiments, the tip electrode array 1302 includes a single electrode.

[0139] For the first spline 1320, for ablation applications, the ring electrodes 1322 can be activated synchronously. Additionally, for mapping applications, the ring electrodes 1322 can be activated independently of each other. For the second spline 1330, for ablation applications, the flexible strut electrode 1332 can be activated without activating the flexible point electrodes 1334 (or, alternatively, the flexible strut electrode 1332 and one or more of the flexible point electrodes 1334 can be activated synchronously). For mapping applications, the flexible point electrodes 1334 can be activated independently of each other (e.g., without activating the flexible strut electrode 1332).

[0140] Those skilled in the art will understand that the first spline 1320 and the second spline 1330 are shown as being included in the same embodiment for purposes of example and for ease of illustration. That is, in some embodiments, a basket catheter assembly can include one or more first splines 1320 and no second splines 1330. In other embodiments, a basket catheter assembly can include one or more second splines 1330 and no first splines 1320. Additionally, in other embodiments, a basket catheter assembly can include a combination of one or more first splines 1320 and one or more second splines 1330 (e.g., as in the catheter assembly 1300).

[0141] In the embodiments described herein, applying energy between one or more pairs of individual electrodes on the device tip generally results in a more uniform lesion area. The uniformity within such an area can also be achieved by applying energy between i) some or all of the electrodes on the tip and ii) a body or intracardiac return electrode.

[0142] Those skilled in the art will appreciate that the various embodiments of the catheter assemblies described herein can be implemented independently of one another or in any suitable combination.

[0143] The embodiments described herein provide a catheter assembly. The catheter assembly includes a tip electrode array including at least one tip electrode located at a distal end of the catheter assembly, and a microelectrode array including a plurality of microelectrodes located proximal to the tip electrode array, wherein each of the at least one tip electrode and each of the plurality of microelectrodes are configured to be activated independently of one another for mapping applications, and wherein at least some of the at least one tip electrode and the plurality of microelectrodes are configured to be activated synchronously for ablation applications.

[0144] Although certain embodiments of the present disclosure have been described above with a certain degree of particularity, those skilled in the art can make various 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, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are for identification purposes only to assist the reader in understanding the present disclosure and do not impose limitations, particularly not on the position, orientation, or use of the present disclosure. Connecting references (e.g., attached, coupled, connected, etc.) should be construed broadly and may include intermediate members between element connections and relative movement between elements. Thus, a connecting reference does not necessarily infer that two elements are directly connected and have a fixed relationship to one another. All content included in the above description or shown in the accompanying drawings should be construed as illustrative only and not restrictive. Changes in details or structure may be made without departing from the spirit of the present disclosure as defined by the appended claims.

[0145] When introducing elements of the present disclosure or its preferred embodiments, the articles "a," "an," "the," and "said" are intended to mean that there is 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.

[0146] Since various changes can be made to the above construction without departing from the scope of the present disclosure, all content included in the above description or shown in the accompanying drawings should be construed as illustrative rather than restrictive.

Claims

1. A catheter assembly, comprising: a tip electrode array including at least one tip electrode, the tip electrode array being located at a distal end of the catheter assembly; and a microelectrode array including a plurality of microelectrodes, the microelectrode array being located proximal to the tip electrode array, wherein each of the at least one tip electrode and each of the plurality of microelectrodes are configured to be independently activated from one another for mapping applications, and wherein at least some of the at least one tip electrode and the plurality of microelectrodes are configured to be synchronously activated for ablation applications.

2. The catheter assembly according to claim 1, wherein, the plurality of microelectrodes includes a plurality of rectangular electrodes arranged in a brick-like pattern.

3. The catheter assembly according to claim 1, wherein, the plurality of microelectrodes includes a plurality of circular electrodes.

4. The catheter assembly according to claim 1, further comprising an annular electrode defining a plurality of holes, wherein, the plurality of microelectrodes are located within the plurality of holes.

5. The catheter assembly according to claim 1, wherein, the at least one tip electrode includes a plurality of tip electrodes, and wherein the tip electrode assembly further includes a plurality of non-conductive segments separating the plurality of tip electrodes.

6. The catheter assembly according to claim 1, wherein, the microelectrode array includes four microelectrodes arranged in a square grid pattern.

7. The catheter assembly according to claim 1, further comprising an annular electrode.

8. The catheter assembly according to claim 7, wherein, the plurality of microelectrodes are formed on the annular electrode.

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

10. The catheter assembly according to claim 1, wherein, the catheter assembly is a basket catheter assembly including a plurality of splines, and wherein the microelectrode array includes at least one of the following: i) a plurality of annular electrodes on a single spline and ii) elongated flexible strut electrodes and a plurality of flexible point electrodes on a single spline.

11. An electroporation system, comprising: 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 including at least one tip electrode, the tip electrode array being located at a distal end of the catheter assembly; and a microelectrode array including a plurality of microelectrodes, the microelectrode array being located proximal to the tip electrode array, wherein each of the at least one tip electrode and each of the plurality of microelectrodes are configured to be independently activated from one another for mapping applications, and wherein at least some of the at least one tip electrode and the plurality of microelectrodes are configured to be synchronously activated for ablation applications.

12. The system according to claim 11, wherein, The plurality of microelectrodes include a plurality of rectangular electrodes arranged in a brick-like pattern.

13. The system according to claim 11, wherein, the plurality of microelectrodes include a plurality of circular electrodes.

14. The system according to claim 11, further comprising an annular electrode defining a plurality of holes, wherein, the plurality of microelectrodes are located within the plurality of holes.

15. The system according to claim 11, wherein, the at least one tip electrode includes a plurality of tip electrodes, and wherein the tip electrode assembly further includes a plurality of non-conductive segments separating the plurality of tip electrodes.

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

17. The system according to claim 11, wherein, the catheter is an annular catheter.

18. An ablation system, comprising: 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, the first generator being configured to deliver a first type of ablation energy to the at least one catheter via the hub; and a second generator coupled to the hub, the second generator being configured to deliver a second type of ablation energy to the at least one catheter via the hub, wherein the console is configured to selectively control the delivery of the first type of ablation energy and the second type of ablation energy to the at least one catheter via the hub.

19. The ablation system according to claim 18, wherein, the first generator is a radiofrequency generator, and wherein the second generator is a pulsed field ablation generator.

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

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