Catheter tip insulator

Abstract

Aspects of the present disclosure relate to devices, systems, and methods that may include a cardiac ablation catheter. The cardiac ablation catheter may include a handle, an elongate shaft, and a distal assembly including a tip electrode, a ring electrode, and an insulator preform.

Description

Technical Field

[0001] The present disclosure relates to medical devices, systems and methods for cardiac ablation. More particularly, the present disclosure relates to spot pulsed field ablation catheters. Background Art

[0002] Ablation procedures are used to treat many different conditions in patients. Ablation can be used to treat arrhythmias, benign tumors, cancerous tumors, and to control bleeding during surgery. Typically, ablation is achieved through thermal ablation techniques, including radio-frequency (RF) ablation and cryoablation. In RF ablation, a probe is inserted into the patient's body, and radio frequency waves are transmitted through the probe to the surrounding tissue. The radio frequency waves generate heat, which destroys the surrounding tissue and seals off blood vessels. In cryoablation, a hollow needle or cryoprobe is inserted into the patient's body, and a cooled heat transfer fluid is circulated through the probe to freeze and kill the surrounding tissue.

[0003] Another ablation technique uses electroporation. In electroporation (or electropermeabilization), an electric field is applied to cells to increase the permeability of the cell membrane. Depending on the strength of the electric field, electroporation can be reversible or irreversible. If electroporation is reversible, the increased permeability of the cell membrane can be used to introduce chemicals, drugs and / or deoxyribonucleic acid (DNA) into the cell before the cell heals and recovers. If electroporation is irreversible, the affected cells are killed by apoptosis.

[0004] Irreversible electroporation (IRE) can be used as a non-thermal ablation technique. In IRE, a sequence of brief, high-voltage pulses is used to generate an electric field strong enough to kill cells by apoptosis. In the ablation of cardiac tissue, IRE can be a safe and efficient alternative to the indiscriminate killing of thermal ablation techniques (such as RF ablation and cryoablation). IRE can be used to kill target tissue by using an electric field strength and duration that kills target tissue (such as myocardial tissue) but does not permanently damage other cells or tissues (such as non-targeted myocardial tissue, red blood cells, vascular smooth muscle tissue, endothelial tissue, and neural cells).

[0005] There is a continuing need for improved catheter devices for performing IRE procedures. Summary of the invention

[0006] In Example 1, a cardiac ablation catheter includes an elongated shaft and a distal assembly. The shaft has a proximal end and a distal end. The distal assembly has a proximal end and a distal end, and its proximal end is fixed to the distal end of the shaft. The distal assembly includes a tip electrode, a first ring electrode, and an insulator preform. The tip electrode is located at the distal end of the distal assembly. The first ring electrode is located proximal to the tip electrode and is spaced apart from the tip electrode. The insulator preform includes a proximal portion having a forward portion defining a first diameter and a distal portion extending distally from the proximal portion, the distal portion having a distal side and a second diameter greater than the first diameter to define a radial shoulder, and a distal portion length. The tip electrode extends distally from a distal side of the insulator preform, and the first ring electrode is disposed above the proximal portion such that a distal leading end of the ring electrode abuts a radial shoulder of the insulator preform, and wherein the distal portion length defines a longitudinal spacing between the tip electrode and a distal leading end of the first ring electrode.

[0007] In Example 2, the cardiac ablation catheter of Example 1, wherein the tip electrode includes a tip electrode shoulder adjacent to a distal surface of the insulator preform.

[0008] In Example 3, a cardiac ablation catheter according to any one of Examples 1 or 2, wherein the distal portion of the insulator preform includes a distal opening in the distal surface.

[0009] In Example 4, a cardiac ablation catheter is provided according to Example 3, wherein the tip electrode comprises: an active portion having an active portion diameter, and a tip electrode shank having a tip electrode shank diameter smaller than the active portion diameter, and wherein the tip electrode shank is received in a distal opening in the distal surface of the insulator preform.

[0010] In Example 5, according to a cardiac ablation catheter according to any one of Examples 1 to 4, the distal component also includes a second ring electrode, which is located proximal to the first ring electrode and is longitudinally spaced apart from the first ring electrode.

[0011] In Example 6, according to a cardiac ablation catheter according to any one of Examples 1 to 5, the distal component also includes an insulating material, and the insulating material is disposed at least proximal to the first ring electrode.

[0012] In Example 7, the cardiac ablation catheter according to Example 6, wherein the insulating material is disposed between the first annular electrode and the second annular electrode.

[0013] In Example 8, the cardiac ablation catheter according to Example 7, wherein the insulating material is formed by an overmolding process.

[0014] In Example 9, the cardiac ablation catheter of Example 8, wherein the insulator preform includes a first longitudinal channel and a second longitudinal channel extending through the proximal portion to a distal portion of the insulator preform.

[0015] In Example 10, the cardiac ablation catheter of Example 9, wherein the insulating material extends through the first and second longitudinal channels and around the tip electrode shank to secure the tip electrode to the insulator preform.

[0016] In Example 11, a cardiac ablation catheter is provided according to Example 9, wherein the tip electrode handle includes a plurality of radial protrusions adjacent to the inner surface of the distal portion of the insulator preform, and wherein the insulating material encapsulates the radial protrusions to secure the tip electrode to the insulator preform.

[0017] In Example 12, a cardiac ablation catheter according to any one of Examples 8 to 11, wherein the tip electrode handle includes a plurality of radial openings extending inwardly.

[0018] In Example 13, the cardiac ablation catheter of Example 12, wherein the insulating material extends through the radial opening to secure the insulator preform to the distal assembly.

[0019] In Example 14, a cardiac ablation catheter according to any one of Examples 1 to 13, wherein the proximal portion of the insulator preform includes a proximal opening and a navigation sensor lumen extending from the proximal opening and terminating in a blind hole.

[0020] In Example 15, the cardiac ablation catheter according to any one of Examples 1 to 14, wherein the proximal portion of the insulator preform has a planar portion that defines a space for accommodating attachment of an electrical conductor to the first annular electrode.

[0021] In Example 16, a cardiac ablation catheter includes a handle, an elongated shaft, and a distal assembly. The shaft has a proximal end and a distal end, and the proximal end extends distally from the handle. The distal assembly has a proximal end and a distal end, and the proximal end is fixed to the distal end of the shaft. The distal assembly includes a tip electrode, a first ring electrode, and an insulator preform. The tip electrode is located at the distal end of the distal assembly. The first ring electrode is located proximal to the tip electrode and is spaced apart from the tip electrode, and the first ring electrode has a distal leading end and a proximal trailing end. The insulator preform includes a proximal portion having a forward portion defining a first diameter and a distal portion extending distally from the proximal portion, the distal portion having a distal side and a second diameter greater than the first diameter to define a radial shoulder, and a distal portion length. The tip electrode extends distally from a distal side of the insulator preform, and the first ring electrode is disposed above the proximal portion such that a distal leading end of the ring electrode abuts a radial shoulder of the insulator preform, and wherein the distal portion length defines a longitudinal spacing between the tip electrode and a distal leading end of the first ring electrode.

[0022] In Example 17, the cardiac ablation catheter of Example 16, wherein the tip electrode includes a tip electrode shoulder adjacent to a distal surface of the insulator preform.

[0023] In Example 18, the cardiac ablation catheter of Example 17, wherein the distal portion of the insulator preform includes a distal opening in the distal surface.

[0024] In Example 19, a cardiac ablation catheter is provided according to Example 18, wherein the tip electrode comprises: an active portion having an active portion diameter, and a tip electrode shank having a tip electrode shank diameter smaller than the active portion diameter, and wherein the tip electrode shank is received in a distal opening in the distal surface of the insulator preform.

[0025] In Example 20, the cardiac ablation catheter of Example 19, wherein the distal assembly further comprises a second annular electrode located proximal to the first annular electrode and longitudinally spaced apart from the first annular electrode.

[0026] In Example 21, according to the cardiac ablation catheter of Example 20, the distal component also includes an insulating material, and the insulating material is disposed at least proximal to the first ring electrode.

[0027] In Example 22, the cardiac ablation catheter of Example 21, wherein the insulating material is disposed between the first annular electrode and the second annular electrode.

[0028] In Example 23, the cardiac ablation catheter of Example 22, wherein the insulator preform includes: a first longitudinal channel and a second longitudinal channel extending through the proximal portion to the distal portion of the insulator preform.

[0029] In Example 24, the cardiac ablation catheter of Example 23, wherein the insulating material extends through the first and second longitudinal channels and around the tip electrode shank to secure the tip electrode to the insulator preform.

[0030] In Example 25, a cardiac ablation catheter is provided according to Example 23, wherein the tip electrode handle comprises: a plurality of radial protrusions adjacent to the inner surface of the distal portion of the insulator preform, and wherein the insulating material encapsulates the radial protrusions to secure the tip electrode to the insulator preform.

[0031] In Example 26, the cardiac ablation catheter of Example 22, wherein the tip electrode handle includes a plurality of radial openings extending inwardly, and wherein the insulating material extends through the radial openings to secure the insulator preform to the distal assembly.

[0032] In Example 27, the cardiac ablation catheter of Example 26, wherein the proximal portion of the insulator preform includes a proximal opening and a navigation sensor lumen extending from the proximal opening and terminating in a blind hole.

[0033] In Example 28, the cardiac ablation catheter of Example 27, wherein the proximal portion of the insulator preform has a planar portion that defines a space for accommodating attachment of an electrical conductor to the first annular electrode.

[0034] In Example 29, an ablation electrode assembly for a pulsed field ablation catheter, the ablation electrode assembly comprising an insulator preform, a tip electrode and a ring electrode. The insulator preform comprises a proximal portion having a forward portion defining a first diameter and a distal portion extending distally from the proximal portion, the distal portion having a distal side and a second diameter greater than the first diameter thereby defining a radial shoulder, and a distal portion length. The tip electrode extends distally from the distal side of the insulator preform. The ring electrode is disposed above the proximal portion of the insulator preform so that the distal leading end of the ring electrode abuts the radial shoulder of the insulator preform, and wherein the distal portion length of the insulator preform defines the longitudinal spacing between the tip electrode and the distal leading end of the first ring electrode.

[0035] In Example 30, the cardiac ablation catheter of Example 29, wherein the tip electrode includes a tip electrode shoulder adjacent to a distal surface of the insulator preform.

[0036] In Example 31, the cardiac ablation catheter of Example 30, wherein the distal portion of the insulator preform includes a distal opening in the distal surface.

[0037] In Example 32, a cardiac ablation catheter is provided according to Example 31, wherein the tip electrode includes an active portion having an active portion diameter and a tip electrode shank having a tip electrode shank diameter smaller than the active portion diameter, and wherein the tip electrode shank is received within a distal opening in the distal surface of the insulator preform.

[0038] In Example 33, a cardiac ablation catheter is provided according to Example 29, wherein the insulator preform includes a first longitudinal channel and a second longitudinal channel extending through the proximal portion to the distal portion of the insulator preform, and wherein an insulating material extends through the first longitudinal channel and the second longitudinal channel and surrounds the tip electrode handle to secure the tip electrode to the insulator preform.

[0039] In Example 34, a method for manufacturing an ablation electrode assembly for a cardiac ablation catheter comprises: providing an insulator preform, the insulator preform comprising a proximal portion having a forward portion defining a first diameter and a distal portion extending distally from the proximal portion, the distal portion having a distal side with a distal opening, a second diameter greater than the first diameter thereby defining a radial shoulder, and a distal portion length; fixing a tip electrode to the distal portion of the insulator preform such that the tip electrode extends distally from the distal side of the insulator preform; and fixing a ring electrode above the proximal portion of the insulator preform such that the distal leading end of the ring electrode abuts the radial shoulder of the insulator preform, wherein the distal portion length of the insulator preform defines a longitudinal spacing between the tip electrode and the distal leading end of the first ring electrode.

[0040] In Example 35, a method is described according to Example 34, wherein the tip electrode includes an active portion having an active portion diameter and a tip electrode shank having a tip electrode shank diameter smaller than the active portion diameter, and wherein fixing the tip electrode to the insulator preform includes: inserting the tip electrode shank into a distal opening in a distal surface of the insulator preform.

[0041] Although multiple embodiments are disclosed, other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the present invention. Therefore, the drawings and detailed description should be regarded as illustrative in nature and not restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic diagram illustrating an exemplary clinical setting for treating a patient using a cardiac ablation catheter according to an embodiment of the disclosed subject matter;

[0043] Figure 2 According to the embodiment of the present disclosure Figure 1 An isometric view of a distal portion of a cardiac ablation catheter (including a distal assembly) depicted in;

[0044] Figure 3A and Figure 3B According to the embodiment of the present disclosure Figure 1 An isometric view and a cross-sectional isometric view of an insulator preform used in a distal assembly of a cardiac ablation catheter;

[0045] Figure 3C According to the embodiment of the present disclosure Figure 1 A plan view of an insulator preform used in a distal assembly of a cardiac ablation catheter;

[0046] Figure 4 According to the embodiment of the present disclosure Figure 1 A cross-sectional elevation view of a portion of a distal assembly of a cardiac ablation catheter depicted in;

[0047] Figure 5 is an alternative embodiment of the present disclosure for Figure 1 An elevation view of an insulator preform used in a distal assembly of a cardiac ablation catheter;

[0048] Figure 6 is an alternative embodiment of the present disclosure for Figure 1 An elevation view of an insulator preform used in a distal assembly of a cardiac ablation catheter;

[0049] Figure 7 According to the embodiment of the present disclosure Figure 1 An isometric view of a tip electrode used in a distal assembly of a cardiac ablation catheter;

[0050] Fig. 8A and Figure 8B According to the embodiment of the present disclosure Figure 1 Illustration of an alternative design of a tip electrode for use in a distal assembly of a cardiac ablation catheter;

[0051] Fig. 9 According to the embodiment of the present disclosure Figure 1 A cross-sectional view of another alternative design of a tip electrode for use in a distal assembly of a cardiac ablation catheter;

[0052] Fig.10 According to the embodiment of the present disclosure Figure 1 Elevation view of the handle of a cardiac ablation catheter.

[0053] Although the present invention is applicable to various modifications and alternative forms, specific embodiments have been shown in the drawings by way of example and are described in detail below. However, it is not intended to limit the present invention to the specific embodiments described. On the contrary, the present invention is intended to cover all modifications, equivalents and substitutes within the scope of the present invention as defined by the appended claims. DETAILED DESCRIPTION

[0054] The following detailed description is exemplary in nature and is not intended to limit the scope, applicability or configuration of the present invention in any way. On the contrary, the following description provides some practical instructions for implementing exemplary embodiments of the present invention. Examples of construction, materials and / or dimensions are provided for selected elements. Those skilled in the art will recognize that many of the examples mentioned have a variety of suitable alternatives.

[0055] As used herein with respect to measurements (e.g., dimensions, characteristics, attributes, components, etc.) and ranges thereof of tangible things (e.g., products, inventory, etc.) and / or intangible things (e.g., data, electronic representations of currency, accounts, information, parts of things (e.g., percentages, fractions), calculations, data models, dynamic system models, algorithms, parameters, etc.), the terms "about" and "approximately" may be used interchangeably to refer to any measurement that includes the stated measurement and also includes any measurement that is fairly close to the stated measurement but may differ by a fairly small amount, such small differences as would be understood by a person of ordinary skill in the relevant art. And easily determined to be attributable to: measurement errors; differences in calibration of measurement and / or manufacturing equipment; human errors in reading and / or setting measurements; adjustments to optimized performance and / or structural parameters in view of other measurements (e.g., measurements associated with other things); specific implementation scenarios; inaccurate adjustments and / or manipulations of things, settings and / or measurements by people, computing devices and / or machines; system tolerances; control loops; machine learning; foreseeable changes (e.g., statistically insignificant changes, chaotic changes, system and / or model instabilities, etc.); preferences; and / or the like.

[0056] Although the illustrative method may be represented by one or more figures (e.g., flow charts, communication flows, etc.), these figures should not be interpreted as implying any requirements of the various steps disclosed herein, or a specific order among or between them. However, certain embodiments may require certain steps and / or certain orders between certain steps, as can be clearly described in this article and / or as can be understood from the nature of the steps themselves (e.g., the execution of certain steps may depend on the results of previous steps). Additionally, a "set", "subset" or "group" of items (e.g., inputs, algorithms, data values, etc.) may include one or more items, and similarly, a subset or subgroup of items may include one or more items. "Multiple" means more than one.

[0057] As used herein, the term "based on" is not meant to be limiting, but rather to indicate that a determination, identification, prediction, calculation, and / or the like is performed using at least the term following "based on" as input. For example, predicting an outcome based on a particular piece of information may additionally or alternatively base the same determination on another piece of information.

[0058] Irreversible electroporation (IRE) uses high voltage, short (e.g., 100 microseconds) pulses to kill cells by apoptosis. IRE can be targeted to kill myocardium, thereby avoiding damage to other adjacent tissues including esophageal vascular smooth muscle and endothelium. Failure of dielectric isolation between ablation poles may cause treatment energy to be shunted through the catheter instead of being delivered to the target tissue, and may cause unintentional arcing or localized high currents that may cause damage to the catheter and / or possibly surrounding tissue. Therefore, with the introduction of high voltage treatments used in IRE, there is a need for robust dielectric isolation between circuits throughout the catheter, especially in the tip region of the catheter where treatment is delivered.

[0059] Current catheter processes rely on material flow to seal joints and prevent fluid pathways between exposed conductors (i.e., backflow and bonded joints). In these processes, voids or bubbles may form and may be difficult to identify.

[0060] At least some embodiments of the present disclosure are intended to provide a guaranteed insulation layer between all conductive surfaces and the wires that are at a high potential relative to each other in the tip region of the catheter. In some embodiments, the electroporation ablation system includes a point electroporation ablation catheter having an insulator preform. As used herein, a point catheter refers to a catheter having a linear body carrying an ablation electrode. In an embodiment, the point catheter has an ablation electrode toward its distal end.

[0061] Figure 1is a schematic diagram illustrating an exemplary clinical environment 10 for treating a patient 20 and treating a heart 30 of the patient 20 using an electrophysiology system 50 in accordance with an embodiment of the disclosed subject matter. The electrophysiology system 50 includes an electroporation device 60 and an optional localization field generator 80. In addition, the clinical environment 10 also includes additional equipment, such as an imaging device 94 (represented by a C-arm) and various controller elements configured to allow an operator to control various aspects of the electrophysiology system 50. As will be appreciated by a skilled artisan, the clinical environment 10 may have Figure 1 Other components and component arrangements not shown.

[0062] The electroporation device 60 includes a cardiac ablation catheter 105, an introducer sheath 110, a controller 90, and an electroporation generator 130. In an embodiment, the electroporation device 60 is configured to deliver electric field energy to a target tissue in the patient's heart 30 to produce tissue apoptosis, rendering the tissue unable to conduct electrical signals. The controller 90 is configured to control functional aspects of the electroporation device 60. In an embodiment, the controller 90 is configured to control the electroporation generator 130 to generate electrical pulses, such as the amplitude of the electrical pulses, the timing of the electrical pulses, and the duration. In an embodiment, the electroporation generator 130 is operable as a pulse generator for generating a pulse sequence and supplying the pulse sequence to the cardiac ablation catheter 105.

[0063] In embodiments, the introducer sheath 110 is operable to provide a delivery conduit through which the cardiac ablation catheter 105 can be deployed to a specific target site within the patient's heart 30. However, it will be understood that the introducer sheath 110 is shown and described herein to provide context to the overall electrophysiology system 50.

[0064] In the illustrated embodiment, the cardiac ablation catheter 105 includes a handle 105a, an elongated shaft 105b, and a distal assembly 150. As shown, the shaft has a distal end 105c and a proximal end 105d, and the proximal end 105d of the shaft 105b extends distally from the handle 105a. The handle 105a is configured to be operated by a user to position the distal assembly 150 at a desired anatomical position. The shaft 105b generally defines the longitudinal axis of the cardiac ablation catheter 105. The shaft 105b may include a molded articulated joint for spinal reinforcement and steering capability. More details can be found in U.S. Patent Application 63 / 129,960, which is incorporated herein by reference in its entirety.

[0065] As shown, distal assembly 150 is located at or near distal end 105c of shaft 150b. In embodiments, distal assembly 150 is electrically coupled to electroporation generator 130 to receive a sequence or train of electrical pulses to selectively generate an electric field for ablating target tissue by irreversible electroporation.

[0066] In some embodiments, the cardiac ablation catheter 105 is a point-type catheter including a linear body toward the distal end. In an embodiment, the distal assembly 150 includes one or more electrodes disposed on the shaft 105b. In some embodiments, the distal assembly 150 includes one or more electrode pairs. In some embodiments, the distal assembly 150 includes one or more ablation electrodes and one or more sensing electrodes. In some embodiments, the distal assembly 150 includes a pair of ablation electrodes, which are configured to generate an electric field sufficient for irreversible electroporation ablation. In some examples, the ablation electrode pair includes a tip electrode covering the distal end of the catheter 105 and a ring electrode disposed near the tip electrode. As used herein, a ring electrode refers to an electrode having a ring shape. In some designs, the pair of ablation electrodes includes two ring electrodes disposed near the distal end of the catheter 105.

[0067] In an embodiment, the electrode position and size are specifically designed to allow flexibility. For example, the electrode is designed to be relatively short in length. For another example, two electrodes have a relatively large spacing to allow flexibility and / or deflection. In some examples, one or more electrodes include one or more pairs of ablation electrodes and one or more pairs of sensing electrodes. The sensing electrodes can be used to sense electrical signals associated with the patient's heart, which allows an operator or system to determine whether ablation has occurred. In some designs, the electrical signals can be used to determine the position or nearby position of the cardiac ablation catheter 105. In some embodiments, other sensors, such as force sensors, navigation sensors (e.g., five-degree-of-freedom or six-degree-of-freedom ("degree-of-freedom, DoF") sensors) can be incorporated in the distal assembly 150.

[0068] In some embodiments, one or more sensing electrodes on the electroporation catheter 105 can measure electrical signals and generate output signals, which can be processed by a controller (e.g., controller 90) to generate an electroanatomical map. In some instances, the electroanatomical map is generated before ablation to determine the electrical activity of cardiac tissue in the chamber of interest. In some instances, the electroanatomical map is generated after ablation to verify the desired changes in the electrical activity of the ablated tissue and chamber as a whole. The sensing electrodes can be used to determine the position of the catheter 105 in three-dimensional space in the body. For example, when the operator moves the catheter 105 in the patient's heart chamber, the boundaries of the catheter movement can be determined by the controller 90, which can include or be coupled to a mapping and navigation system to form the anatomical structure of the chamber. The chamber anatomical structure can be used to facilitate navigation of the catheter 105 without the use of ionizing radiation such as fluoroscopy, and to mark the location of the ablation when the ablation is completed, thereby guiding the spacing of the ablation and assisting the operator to completely ablate the anatomical structure of interest.

[0069] Depending on the embodiment, the various components of the electrophysiology system 50 (e.g., the controller 90) may be implemented on one or more computing devices. The computing device may include any type of computing device suitable for implementing the embodiments of the present disclosure. Examples of computing devices include dedicated computing devices or general-purpose computing devices such as workstations, servers, laptops, portable devices, desktop computers, tablet computers, handheld devices, general-purpose graphics processing units (GPGPUs), and similar devices, all of which refer to the various components of the system 50 in Figure 1 is considered within the scope of

[0070] In some embodiments, a computing device includes a bus that directly and / or indirectly couples the following devices: a processor, a memory, an input / output (I / O) port, an I / O component, and a power supply. Any number of additional components, different components, and / or combinations of components may also be included in the computing device. A bus represents content that may be one or more buses (such as, for example, an address bus, a data bus, or a combination thereof). Similarly, in some embodiments, a computing device may include multiple processors, multiple memory components, multiple I / O ports, multiple I / O components, and / or multiple power supplies. Additionally, any number of these components or combinations thereof may be distributed and / or replicated across multiple computing devices.

[0071] In some embodiments, the system 50 includes one or more memories (not shown). The one or more memories include computer-readable media in the form of volatile and / or non-volatile memory, temporary and / or non-temporary storage media, and may be removable, non-removable, or a combination thereof. Examples of media include random access memory (RAM); read-only memory (ROM); electronically erasable programmable read-only memory (EEPROM); flash memory; optical or holographic media; magnetic cassettes, tapes, disk storage or other magnetic storage devices; data transmission; and / or any other medium that can be used to store information and can be accessed by a computing device, such as, for example, quantum state memory, and / or the like. In some embodiments, the one or more memories store computer-executable instructions for causing a processor (e.g., controller 90) to implement aspects of embodiments of system components discussed herein and / or to perform aspects of embodiments of methods and processes discussed herein.

[0072] Computer executable instructions may include, for example, computer code, machine usable instructions, and similar instructions, such as program components that can be executed by one or more processors associated with a computing device. Program components can be programmed using any number of different programming environments (including various languages, development kits, frameworks, and / or the like). Additionally or alternatively, some or all of the functionality contemplated herein may be implemented in hardware and / or firmware.

[0073] In some embodiments, the memory may include a data repository, which may be implemented using any of the configurations described below. The data repository may include random access memory, flat files, XML files, and / or one or more database management systems (DBMS) executed on one or more database servers or data centers. The database management system may be a relational (RDBMS), hierarchical (HDBMS), multidimensional (MDBMS), object-oriented (ODBMS or OODBMS) or object-relational (ORDBMS) database management system, and similar database management systems. The data repository may be, for example, a single relational database. In some cases, the data repository may include multiple databases that may exchange and aggregate data through a data integration process or software application. In an exemplary embodiment, at least a portion of the data repository may be hosted in a cloud data center. In some cases, the data repository may be hosted on a single computer, server, storage device, cloud server, or the like. In some other cases, the data repository may be hosted on a series of networked computers, servers, or devices. In some cases, the data repository may be hosted on a layer of data storage devices including local, regional, and central.

[0074] The various components of the system 50 may communicate or be coupled via a communication interface (e.g., a wired or wireless interface). The communication interface includes, but is not limited to, any wired or wireless short-range and long-range communication interface. A wired interface may use a cable, an umbilical cable, and the like. A short-range communication interface may be, for example, a local area network (LAN), an interface conforming to a known communication standard, such as standards, IEEE 802 standards (such as IEEE 802.11), Or similar specifications such as those based on the IEEE 802.15.4 standard or other public or proprietary wireless protocols. The long-distance communication interface can be, for example, a wide area network (WAN), a cellular network interface, a satellite communication interface, etc. The communication interface can be within a private computer network such as an intranet, or on a public computer network such as the Internet.

[0075] As will be explained in greater detail elsewhere herein, various embodiments of the present disclosure, and in particular the distal assembly 150, employ novel structural features to improve the clinical performance and enhance the manufacturability of the ablation catheter 105. Specifically, the distal assembly 150 includes an insulator preform that, among other things, supports and positions the tip electrode and adjacent ring electrodes, and operates to electrically insulate the various electrical components of the distal assembly 150.

[0076] Figure 2is an isometric view of the distal portion of the cardiac ablation catheter 200. In an embodiment, the cardiac ablation catheter 200 corresponds to Figure 1 The ablation catheter 105 is shown and includes a distal assembly 202 .

[0077] As shown, the distal assembly 202 is arranged along the axis ( Figure 2 204 is axially arranged along a longitudinal axis 204 defined by the distal assembly 202 (not shown). The distal assembly 202 includes a pair of electrodes 208, the pair of electrodes including a tip electrode 212 and a ring electrode 214, the tip electrode 212 is located at the distal end of the distal assembly 202, and the ring electrode 214 is located proximal to the tip electrode 212 and spaced apart from the tip electrode 212. As shown, the ring electrode has a distal leading end 214a and a proximal trailing end 214b. In an embodiment, the distal assembly 202 may include additional electrodes such as an additional electrode pair 210, which includes electrodes 216, 218, which are disposed proximal to the electrodes 212 and 214 and spaced longitudinally apart from the electrodes 212 and 214. More or fewer electrodes may be used in other embodiments within the scope of the present disclosure.

[0078] The specific operation of the various electrodes (or electrode pairs) can vary depending on the specific clinical use of the ablation catheter 200. In an embodiment, the electrodes 212, 214, 216 and 218 can be configured to operate as ablation electrodes, sensing electrodes, or both. For example, any or all of the electrodes 212, 214, 216 and 218 can be configured to be operable for delivery of ablation energy to target tissue. Additionally or alternatively, any or all of the electrodes 212, 214, 216 and 218 can be operable as sensing electrodes that are configured to sense electrical signals (e.g., intrinsic cardiac activation signals and / or electric fields generated by injected currents for impedance-based position tracking, tissue proximity or contact sensing, etc.). In one embodiment, the pair of electrodes 208 can be configured to operate as ablation electrodes, such as for bipolar delivery of ablation energy, and in particular pulsed field ablation energy for focal ablation of cardiac tissue. In an embodiment, electrodes 216, 218 may be operable as sensing electrodes, or alternatively operable as ablation electrodes. In some cases, the second pair of electrodes 210 is configured to measure local impedance and may act as a position sensor for sensing local electric fields with 5 degrees of freedom (e.g., 5 different motions - x, y, z, acceleration, and rotation). In an embodiment, except as specifically described herein, electrodes 212, 214, 216, and 218 may be configured according to those described in co-pending and co-assigned U.S. Patent Application 63 / 194,716, which is incorporated herein by reference in its entirety.

[0079] In one exemplary embodiment, electrode pair 212 may be activated using a first polarity and electrode pair 210 may be activated using a second polarity opposite the first polarity, thereby defining an ablation vector and corresponding electric field therebetween.

[0080] However, it should be emphasized that the present disclosure is not limited to Figure 2 Rather, those skilled in the art will appreciate that additional variations in electrode configuration, electrode number, and the like may be employed within the scope of the present disclosure.

[0081] In the illustrated embodiment, the distal assembly 202 also includes a steering ring 222 located at the proximal end of the distal assembly 202. The steering ring 222 is mechanically connected to one or more steering wires 224, which are connected to a steering mechanism located in the handle (not shown) of the ablation catheter 200 and are configured to allow a user to steer the catheter 200 during operation. It should be emphasized that Figure 2 The particular steering ring 222 shown is for illustration only and is in no way limiting. Generally, mechanisms for implementing steerability or deflectability of ablation catheters are well known, and thus those skilled in the art will recognize that a wide range of steering techniques may be employed in ablation catheter 200 .

[0082] In an embodiment, as shown, the distal assembly 202 includes an insulator preform 220, a portion of which is located between the tip electrode 212 and the ring electrode 216. In the illustrated embodiment, the insulator preform 220 includes a distal portion 220a and a proximal portion 220b ( Figure 2 As shown, the distal portion 220a defines a distal portion length L1. As further shown, the distal portion 220a of the preform 220 is disposed between the tip electrodes 212, and the ring electrode 214 is disposed over a portion of the proximal portion 220b such that the distal leading end 214a of the ring electrode 214 abuts against a radial shoulder ( FIG. 3A to FIG. 3C as well as Figure 4 20 ). The distal portion length L1 defines a longitudinal spacing along the longitudinal axis 204 between the tip electrode 212 and the distal leading end 214a of the ring electrode 214. In an embodiment, the insulator preform 220 provides an insulating layer between the conductive surfaces and the wires that are at a high potential relative to each other in the tip region of the catheter. In various embodiments, the length L1 is in the range of about 0.5 mm to 4.5 mm. In certain embodiments, the length L1 is about 1 mm to 4 mm. In certain embodiments, the length L1 is about 2.5 mm to about 3.5 mm. In some embodiments, the length L1 is about 1 mm to 2 mm.

[0083] In some cases, the insulator preform provides a means for routing the wire 226 through the distal assembly 202. In some cases, the insulator preform provides positive placement features for the tip component to allow for better component spacing and assembly into subsequent process steps (i.e., mold assembly). In some cases, the insulator preform provides protection for components of the cardiac ablation catheter 200 (such as navigation sensors or thermocouples) during various conditions of use.

[0084] In an embodiment, the distal assembly 202 also includes an insulating material 230 that is disposed at least proximal to the ring electrode 214 and encapsulates and forms an outer insulating surface of the distal assembly 202. In an embodiment, the insulating material 230 is disposed between the ring electrode 214 and the ring electrode 216. In an embodiment, the insulating material 230 is formed by an overmolding process. Alternatively, the insulating material 230 may also be formed using a reflow process, wherein one or more tubular sections of the insulating material are disposed around the partially assembled distal assembly 202 and then heated, as is known in the art. In an embodiment, employing an overmolding process to provide the insulating material 230 may have certain advantages, such as reducing or even eliminating the need for subsequent processing (such as injection of a medical adhesive to complete the assembly process and provide a fluid-tight connection between the various components). The insulating material may be commercially available. 55D and 55D. Both materials can be used in overmolding processes and bonded to “epoxy bondable” wire insulation. Pellethane can be bonded using a primer (such as Sivate TM E610) and plasma bonded to the tip insulator. Pebax can be bonded to the tip insulator without plasma using an adhesive such as Thermedics 1-MP.

[0085] FIG. 3A to FIG. 3C According to the embodiments of the present disclosure Figure 1 Isometric, cross-sectional isometric, and plan views of an embodiment of an insulator preform 300 for use in a distal assembly of a cardiac ablation catheter.

[0086] As shown, the insulator preform 300 includes a distal portion 302 having a distal portion length L1 and a proximal portion 304 having a diameter d2 and a proximal portion length L2. In the illustrated embodiment, the proximal portion 304 has a forward portion 304f and a rearward portion 304r extending proximally relative to the forward portion 304f. In an embodiment, the rearward portion 304r may be omitted.

[0087] As shown, the distal portion 302 extends distally from the forward portion 304f of the proximal portion 304 and has a maximum diameter d1. Additionally, the forward portion 304f of the proximal portion 304 has a maximum diameter d2. As further shown, the diameter d1 of the distal portion 302 is greater than the diameter d2 of the forward portion 304f of the proximal portion 304, thereby defining a radial shoulder 306 at the intersection of the distal portion 302 and the forward portion 304f of the proximal portion. As further discussed elsewhere herein, the dimensions of the forward portion 304f are designed so that the annular electrode (e.g., Figure 2 A ring electrode 214 in may be disposed above it.

[0088] In an embodiment, the distal portion 302 of the preform 300 is generally cylindrical and includes a distal side 308 and a distal opening 310 in the distal side 308, wherein the interior of the distal portion 302 defines a distal portion cavity 329. In the illustrated embodiment, the preform 300 includes longitudinal passages 312 and 314 extending through the forward portion 304f of the proximal portion 304 to the distal portion 302. FIG. 3A to FIG. 3C When present as in the embodiment of the present invention, longitudinal channels 312 and 314 are designed to facilitate the transmission of overmolding material or adhesive material through the forward portion 304f and into the distal portion cavity 329 to enhance the mechanical attachment of the tip electrode to the insulator preform 300 during the manufacture of the distal assembly of the ablation catheter. In embodiments, one or both of the longitudinal channels 312 and 314 may be omitted.

[0089] In some embodiments, as shown, the rearward portion 304r of the proximal portion 304 has a smaller diameter than the forward portion 304f and includes one or more ribs 316. When present, the ribs 316 operate to enhance the adhesion of the overmold resin (i.e., Figure 2 Mechanical retention of the insulating material in question) or medical adhesive.

[0090] In an embodiment, the insulator preform 300 includes various structural features to facilitate the electrodes (such as Figure 2 The proximal portion 304 includes a proximal wire groove 331 and a proximal wire groove 332 to allow the wire to be connected to the ring electrode 214 ( Figure 2 ) attachment, and overmolding resin (i.e. Figure 2The cut-out flat area 318 is located in the ring electrode landing area 320 of the forward portion 304f of the proximal portion 304, thereby facilitating alignment of the ring electrode and the tip electrode. In an embodiment, the ring electrode landing area 320 can be sized to allow the overmolding resin (i.e. Figure 2 ) flows under the proximal end of the ring electrode to help create a stable connection. Similarly, in the illustrated embodiment, the preform 300 includes a distal wire groove 350 extending along the interior of the distal portion 302 to facilitate the connection of the wire to the tip electrode. In an embodiment, in addition to accommodating the aforementioned electrical connections, the proximal wire groove 331 and the distal wire groove 350 can also assist in orienting the corresponding electrode relative to the preform 300. In the illustrated embodiment, the proximal portion 304 of the insulator preform 300 may include a proximal opening 326 and a navigation sensor lumen 328 extending from the proximal opening 326 and terminating at the closed end 330 to form a blind hole. When present, the navigator sensor lumen 328 can be sized and configured to receive a magnetic tracking sensor to achieve magnetic positioning of the corresponding ablation catheter. In other embodiments, the preform 300 may include additional structural features to accommodate additional sensors (e.g., temperature sensors, pressure sensors, etc.) and corresponding electrical conductors. However, it should be emphasized that the inclusion of the aforementioned wire and sensor housing and orientation features is not a requirement of the present disclosure, and in embodiments, some or all of these features may be omitted or configured in a manner different from the specific exemplary embodiments shown.

[0091] In various embodiments, and with reference to Figure 2 , the distal portion length L1 is selected to precisely define the desired spacing between the trailing proximal edge of the tip electrode 212 and the leading distal edge of the ring electrode 214 while providing the necessary electrical insulation between the two electrodes. The disclosed configuration thus advantageously provides consistent and precise electrode spacing, which is particularly advantageous for use in a pulsed electric field ablation catheter.

[0092] exist FIG. 3A to FIG. 3C In the embodiment of the present invention, the proximal portion length L2 is selected to optimize the overall stiffness of the corresponding distal assembly and the stress concentration at the ring electrode disposed above the proximal portion 304, while still providing sufficient structural material to accommodate attachment to the catheter shaft. Additionally, the reduced diameter rearward portion 304r of the proximal portion 304 is an overmolded resin (i.e., Figure 2 The insulating material in question provides sufficient space to flow around the various wires to reduce fluid leakage during the overmolding process.

[0093] In various embodiments, the insulator preform 300 can be made of any suitable biocompatible insulating material (e.g., plastic, ceramic, etc.) to provide the desired structural and dielectric properties required for the specific clinical application of the cardiac ablation catheter. In embodiments, the preform 300 can be prefabricated using any number of manufacturing processes, for example, it can be machined, molded, cast, or manufactured by an additive manufacturing process. In embodiments, exemplary materials for the preform 300 include, but are not limited to, polycarbonate, which is transparent to allow UV curing adhesives and is also machinable. The insulating material of the insulator preform 300 is provided by isolating the tip electrode, ring electrode, and navigation sensor (when present) and being independent of the overmolding resin or reflow insulation (i.e., Figure 2 other electrical components (of the insulating material discussed) to ensure dielectric insulation.

[0094] Figure 4 is in a partially assembled state Figure 2 4 is a cross-sectional elevation view of a portion of a distal assembly corresponding to the distal assembly 202 of the embodiment of the present invention. As shown, the distal assembly 202 includes an insulator preform 400 and a tip electrode 402 fixed to the insulator preform, and an electrical conductor wire 403 is fixed to the tip electrode 402. As shown, the tip electrode 402 extends distally from a distal side 404 of the insulator preform 400. The tip electrode 402 includes a tip electrode shoulder 406 adjacent to the distal side 404 of the insulator preform 400. The tip electrode 402 has an active portion 408 and a tip electrode shank 410, the active portion 408 having an active portion diameter d3, and the tip electrode shank 410 having a tip electrode shank diameter that is smaller than the active portion diameter. The tip electrode shank 410 is received in a distal opening 412 in the distal side 404 of the insulator preform 400. As described above, the tip electrode shank 410 is secured within the distal portion of the insulator preform 400 via an overmolded insulating material and / or adhesive. In an embodiment, the tip electrode shank 410 includes one or more radial protrusions 414 that abut the inner surface of the insulator preform distal portion 416. During the overmolding process, the insulating material encapsulates the radial protrusions 414 to secure the tip electrode 402 to the insulator preform 400.

[0095] Figure 5 is an alternative embodiment according to the present disclosure Figure 1 An elevation view of an insulator preform 500 for use in a distal assembly of a cardiac ablation catheter. Figure 5Except as described, the insulator preform 500 is substantially the same as the insulator preform 300 described above. Thus, the insulator preform 500 includes a distal portion 502 and a proximal portion 504 having a rearward portion 504r that includes a proximal tapered portion 506. The tapered portion 506 may operate to provide strain relief, for example, to reduce stress between the preform 500 and an overmold material used to encapsulate various internal components of the distal assembly in a final product.

[0096] Figure 6 According to an alternative embodiment of the present invention Figure 1 An elevation view of an insulator preform 600 used in a distal assembly of a cardiac ablation catheter. Typically, as shown, in addition to combining Figure 6 Except as described, the insulator preform 600 is substantially the same as the insulator preform 300 described above. Thus, the insulator preform 600 includes a distal portion 602 having a distal portion length L1 and a proximal portion 604 having a proximal portion length L2. As in the insulator preform 300, the proximal portion of the insulator preform 600 includes a forward portion 604f and a rearward portion 304r. In this embodiment, the proximal portion length L2 is relatively long due to the relatively elongated rearward portion 604r as shown. FIG. 3A to FIG. 3C The relatively long proximal portion 304 provides increased capacity for routing of wiring, inclusion of directional features and support of additional components (e.g., sensors, etc.), as well as providing increased surface area for attaching distal components to the catheter shaft (e.g., via the aforementioned overmolding process).

[0097] Distal assembly 202 ( Figure 2 ) can incorporate a series of distal tip electrodes 212. As will be appreciated by those skilled in the art, the distal tip electrode 212 can advantageously be constructed of or include a material that is visible under fluoroscopy (i.e., a radiopaque material) to assist the clinician in positioning the tip electrode 212, and other electrodes by extension, when present, within the patient's anatomy. One commonly used material is a platinum-iridium (Pt / Ir) alloy, which is radiopaque and electrically conductive, thereby allowing the material to deliver ablative energy to the target tissue. At the same time, Pt / Ir is a relatively expensive material, so minimizing the volume of such material in the tip electrode 212 can be advantageous.

[0098] Figure 7 is an isometric view of an exemplary tip electrode 700, which may correspond to Figure 2 The tip electrode 212. Figure 7As shown, the tip electrode 700 is a two-piece construction having a body 704 and an active housing 708 disposed over a portion of the body 704. As further shown, the body 704 has a proximal portion 712 and an opposite distal portion ( Figure 7 718 is a schematic diagram of a proximal portion 712, wherein the housing 708 is disposed above the distal portion. As further shown, extending from the proximal portion 712 is a handle 716 having a plurality of openings 718. In embodiments, the handle 716 can be received within the distal portion of various insulator preforms described elsewhere herein to facilitate assembly of the tip electrode 700 to the insulator preform. Additionally, when present, the openings 718 can receive attachment materials, such as medical adhesives or overmolding materials, to enhance the mechanical attachment of the tip electrode 700 to the insulator preform. As will be appreciated by those skilled in the art and as described elsewhere herein, the openings 718 are merely an illustrative example of such a fixation enhancement feature that may be employed, but are not required in all embodiments of the present disclosure.

[0099] In one embodiment, the body 704 is made of a relatively inexpensive non-metallic material (e.g., ceramic), while the shell 708 can be formed partially or entirely of a radiopaque and conductive material to facilitate visualization of the tip electrode 700 under fluoroscopy and also operate as an active electrode portion for delivering ablation energy. The aforementioned structure provides the desired electrode function while minimizing the volume of relatively expensive radiopaque material (e.g., Pt / Ir) required for the radiopaque active portion. Because the body 704 is non-conductive, Figure 7 Embodiments include one or more through holes 720 extending through the body 704 to facilitate electrical connection of the active housing 708 and a lead (not shown) for delivery of ablation energy to the housing 708. In other embodiments, the body 704 can be formed of a conductive material (e.g., titanium) that has minimal or no radiopacity but is relatively inexpensive compared to radiopaque materials such as Pt / Ir. ​​In such embodiments, the through hole 720 can be omitted and the required electrical connection to the tip electrode 700 can be made directly to the body 704 (e.g., by attaching the lead directly to the handle 716).

[0100] Fig. 8A and Figure 8B According to some embodiments, Figure 2 8 is an isometric illustration of an alternative tip electrode 800 corresponding to the tip electrode 212 of FIG. Similar to the tip electrode 700 , the tip electrode 800 is a two-piece construction including a body 804 and a radiopaque ring 808 . Fig. 8A An assembled tip electrode 800 is depicted, and Figure 8B Only the body 804 is depicted without the radiopaque ring 808 .

[0101] As shown, the body 804 has a proximal portion 812 and an opposing distal portion 814. Fig. 8A 814, the diameter of the proximal portion 812 is less than the maximum diameter of the distal portion 814, thereby defining a shoulder 815 at the proximal end of the distal portion 814. In the assembled tip electrode 800, the radiopaque ring 808 is disposed above the proximal portion 812 and abuts the shoulder 815. Thus, the assembled tip electrode 800 is substantially isodiametric, i.e., the maximum diameters of the distal portion 814 and the radiopaque ring 808 are substantially the same, thereby minimizing discontinuity between the distal portion 814 and the radiopaque ring 808.

[0102] As further shown, the body 804 includes a handle 816 extending from the proximal portion 812, the handle having a plurality of ribs 818. In embodiments, the handle 816 can be received within a distal portion of various insulator preforms described elsewhere herein to facilitate assembly of the tip electrode 800 to the insulator preform. Additionally, when present, the ribs 818 can provide an increased surface area for attaching the handle 816 to the insulator preform, such as using a medical adhesive or overmolding material, thereby enhancing the mechanical attachment of the tip electrode 800 to the insulator preform. As further shown, in the illustrated embodiment, the handle 816 includes a flat region 820 to facilitate attachment of the wire to the tip electrode 800.

[0103] In an embodiment, the body 804 has a one-piece solid construction formed of a conductive but relatively inexpensive material (e.g., titanium), and the radiopaque ring 808 can be formed of a conductive and radiopaque material (such as Pt / Ir). Similar to the tip electrode 700 described above, the design of the tip electrode 800 provides the desired visibility under fluoroscopy while reducing the volume of relatively expensive radiopaque material used. In an embodiment, the radiopaque ring 808 can be attached to the body 804 using conventional manufacturing techniques (e.g., welding).

[0104] Fig. 9 According to some embodiments, Figure 2900. As shown, the tip electrode 900 includes a body 904 and a housing 908, which together form an electrically active portion of the tip electrode 900. As further shown, the body 904 includes a proximal portion 912 and a distal portion 914, and the housing 908 is disposed above the distal portion 914. The maximum diameter of the proximal portion 912 is greater than the maximum diameter of the distal portion 914 to define a shoulder 915 in the assembled tip electrode 900, and the proximal end of the distal portion 914 abuts the shoulder. As a result, the assembled tip electrode 900 is substantially isodiametric at the junction of the proximal portion 912 and the distal portion 914, i.e., the maximum diameters of the distal portion 914 and the proximal portion 912 are substantially the same, thereby minimizing discontinuity between the distal portion 914 and the proximal portion 812.

[0105] As further shown, the body 904 includes a handle 916 extending from the proximal portion 912, the handle having a plurality of openings 918 and ribs 920. In embodiments, the handle 916 can be received within the distal portion of various insulator preforms described elsewhere herein to facilitate assembly of the tip electrode 800 to the insulator preform. Additionally, when present, the openings 918 and ribs 920 can provide an increased surface area for attaching the handle 916 to the insulator preform, such as using a medical adhesive or overmolding material, thereby enhancing the mechanical attachment of the tip electrode 900 to the insulator preform. In embodiments, the handle 916 can also include features ( Fig. 9 not shown).

[0106] exist Fig. 9 In an embodiment, the tip electrode 900 also includes a radiopaque ring 922 that is disposed between the distal portion 914 of the body 904 and the inner surface of the housing 908. In an embodiment, the body 904 can be constructed of a conductive but relatively inexpensive material (e.g., titanium), and the radiopaque ring 922 can be formed of a conductive and radiopaque material (such as Pt / Ir). Similar to the tip electrodes 700 and 800 described above, the design of the tip electrode 900 provides the desired visibility under fluoroscopy while reducing the volume of the relatively expensive radiopaque material used. In an embodiment, the housing 908 and the radiopaque ring 922 can be attached to the body 904 using conventional manufacturing techniques (e.g., welding).

[0107] Fig.10 is a perspective view of a handle 1000 according to an embodiment of the present disclosure, which may correspond to Figure 1 As described elsewhere herein, the cardiac ablation catheter 105 ( Figure 1) can be a deflectable or steerable catheter whereby the distal portion of the shaft can be selectively deflected or steered by a clinician as required by the particular medical procedure being performed. Handle 1000 can in many respects have a conventional design suitable for use in a deflectable ablation catheter, except for enhancements to accommodate relatively high DC voltages (e.g., in excess of 1000 V) used for pulsed field ablation applications. Fig.10 As shown, the handle 1000 includes a housing 1004 and a nose 1008, the housing being configured to be grasped by a clinician, the nose operating as a transition section through which the catheter shaft and working components (e.g., electrical conductors, steering wires, and the like) extend. In the illustrated embodiment, the handle 1000 also includes a double-winged deflection knob 1012 that can be rotated by the clinician to deflect the distal portion of the shaft in a manner known in the art. Additionally, the proximal end 1014 of the handle 1000 is adapted to be coupled to the distal end of the handle 1000 via a connector assembly 1018 ( Fig.10 ) allows the cardiac ablation catheter 105 to be operably coupled to the electroporation generator 130 ( Figure 1 ) and the entire electrophysiology system 50 ( Figure 1 ) other parts.

[0108] In an embodiment, the housing 1004 may be composed of two or more housing pieces that are joined together to encapsulate various functional components disposed therein. In conventional catheter handle designs, the interface between the handle housing portion, the nose 1008, the deflection knob 1012, and the connector assembly 1018 may include gaps that may create leak paths into the interior of the handle 1000. In various embodiments of the present disclosure, the aforementioned interface is sealed using an epoxy potting material, for example, as illustratively shown at 1024, to fill or substantially fill these gaps in the handle housing. In this way, potential leak points within the handle that may be bridged by saline, moisture, and the like can be substantially sealed. In some embodiments, high-voltage electrode wires (i.e., wires electrically coupled to ablation electrodes for delivering high-voltage PFA pulses) are routed through the handle 1000 to various lead pins (not shown) for further electrical isolation from electrically erasable programmable read-only memory (EEPROM), navigation sensor wires, and other low-voltage circuits.

[0109] Although the present invention is applicable to various modifications and alternative forms, specific embodiments have been shown in the drawings by way of example and are described in detail below. However, it is not intended to limit the present invention to the specific embodiments described. On the contrary, the present invention is intended to cover all modifications, equivalents and substitutes within the scope of the present invention as defined by the appended claims.

[0110] Various modifications and additions may be made to the exemplary embodiments discussed without departing from the scope of the invention. For example, while the embodiments described above relate to specific features, the scope of the invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Therefore, the scope of the invention is intended to encompass all such substitutions, modifications and variations as fall within the scope of the claims, and all their equivalents.

Claims

1. A cardiac ablation catheter, comprising: an elongated shaft having a proximal end and a distal end; as well as a distal assembly having a proximal end and a distal end, the proximal end of the distal assembly being fixed to the distal end of the shaft, the distal assembly comprising: a tip electrode at a distal end of the distal assembly; a first annular electrode located proximal to and spaced apart from the tip electrode, the first annular electrode having a distal leading end and a proximal trailing end; and an insulator preform comprising: a proximal portion having a forward portion defining a first diameter and a distal portion extending distally from the proximal portion, the distal portion having a distal side and a second diameter greater than the first diameter thereby defining a radial shoulder, and a distal portion length, wherein the tip electrode extends distally from a distal side of the insulator preform, and the first ring electrode is disposed above the proximal portion such that a distal leading end of the first ring electrode abuts a radial shoulder of the insulator preform, and wherein a length of the distal portion defines a longitudinal spacing between the tip electrode and a distal leading end of the first ring electrode.

2. The cardiac ablation catheter according to claim 1, wherein: The tip electrode includes a tip electrode shoulder abutting a distal side of the insulator preform.

3. The cardiac ablation catheter according to any one of claims 1 or 2, wherein: The distal portion of the insulator preform includes a distal opening in the distal face.

4. The cardiac ablation catheter according to claim 3, wherein: The tip electrode includes an active portion having an active portion diameter and a tip electrode shank having a tip electrode shank diameter smaller than the active portion diameter, and wherein the tip electrode shank is received within a distal opening in a distal face of the insulator preform.

5. The cardiac ablation catheter according to any one of claims 1 to 4, wherein: The distal assembly also includes a second ring electrode located proximal to the first ring electrode and longitudinally spaced apart from the first ring electrode.

6. The cardiac ablation catheter according to any one of claims 1 to 5, wherein: The distal assembly also includes an insulating material disposed at least proximal to the first ring electrode.

7. The cardiac ablation catheter according to claim 6, wherein: The insulating material is disposed between the first annular electrode and the second annular electrode.

8. The cardiac ablation catheter according to claim 7, wherein: The insulating material is formed by an overmolding process.

9. The cardiac ablation catheter according to claim 7, wherein: The insulator preform includes a first longitudinal channel and a second longitudinal channel extending through the proximal portion to a distal portion of the insulator preform.

10. The cardiac ablation catheter according to claim 9, wherein: The insulating material extends through the first and second longitudinal passages and around the tip electrode shank to secure the tip electrode to the insulator preform.

11. The cardiac ablation catheter according to claim 9, wherein: The tip electrode shank includes a plurality of radial protrusions that abut an inner surface of a distal portion of the insulator preform, and wherein the insulating material encapsulates the radial protrusions to secure the tip electrode to the insulator preform.

12. The cardiac ablation catheter according to any one of claims 8 to 11, wherein: The tip electrode shank includes a plurality of radial openings extending inwardly.

13. The cardiac ablation catheter according to claim 12, wherein: The insulating material extends through the radial aperture to secure the insulator preform to the distal assembly.

14. The cardiac ablation catheter according to any one of claims 1 to 13, wherein: The proximal portion of the insulator preform includes a proximal opening and a navigation sensor lumen extending from the proximal opening and terminating in a blind hole.

15. The cardiac ablation catheter according to any one of claims 1 to 14, wherein: The proximal portion of the insulator preform has a planar portion defining a space to accommodate attachment of an electrical conductor to the first ring electrode.

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