Catheter shaft construction with exposed braid as electrode

Abstract

An example ablation catheter includes an elongate structure configured to be at least partially inserted into an organ of a patient, the elongate structure including a metal element including a plurality of electrically conductive wires, the plurality of electrically conductive wires including a polymer coated portion and an exposed metal portion. The ablation catheter also includes a plurality of electrodes disposed at the distal portion of the elongate structure. At least one electrode of the plurality of electrodes and the exposed metal portion are configured to provide a current path for pulsed field ablation.

Description

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 381,224, filed on October 27, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present technology relates to ablation catheters. In particular, various examples of the present technology relate to a pulsed field ablation catheter having an element having an exposed metal braid or an exposed metal coil configured to operate as one or more electrodes. Background Art

[0003] Tissue ablation is a medical procedure commonly used to treat conditions such as cardiac arrhythmias, which include atrial fibrillation. To treat cardiac arrhythmias, ablation may be performed to modify tissue in order to stop abnormal electrical propagation and / or interrupt abnormal electrical conduction through cardiac tissue. Ablation techniques include pulsed field ablation (PFA), cryoablation, and radiofrequency (RF) ablation. In particular, RF or pulsed field ablation may be applied via electrodes of an ablation catheter.

[0004] Arrhythmias are a group of conditions that cause irregular heartbeats. Ablation can be used to kill or isolate tissue causing arrhythmias and thereby restore or improve heart function. In addition, optimized control of the applied therapy by specialized tools allows for treatment delivery that can be performed without causing damage to adjacent structures or surrounding tissue, ideally eliminating the need for maintenance treatment regimens, such as medication or cardioversion. Summary of the invention

[0005] The present technology relates to devices for pulsed field ablation using an ablation catheter having a metal element having an exposed metal braid, fabric or mesh or an exposed metal coil that can be used as one or more electrodes and techniques for making such devices. For example, an ablation catheter may include a shaft or elongated structure that includes an anti-kink element or an element for enhancing torque transfer, such as a metal braid (which may also be referred to as a metal braid or metal mesh) or a plurality of metal coils that can add kink resistance and / or structural rigidity to the catheter for insertion into a patient's anatomical structure (such as the patient's heart). The individual metal elements may each include a polymer insulating coating that can provide a level of insulation to prevent or limit electrical conduction between an electrode positioned on the surface of the catheter and the metal braid or metal coil. A polymer sheath coating will typically be applied covering all internal metal elements. The polymer sheath coating may be partially or completely removed from one or more portions of the insulating coating protecting the individual metal braid or metal coil, such as by laser ablation, thermal ablation, or mechanical force, to expose the metal of the selected metal braid wire or metal coil to the surrounding environment. In some examples, the exposed metal may form one or more electrodes. For example, the exposed metal may form one or more return electrodes. Such a return electrode may be coupled to ground or to the opposite polarity of a pulsed field ablation generator. Alternatively or in addition, the exposed metal may be electrically coupled to one or more electrodes and thus act as a conductor for the one or more electrodes, rather than acting as an electrode.

[0006] According to one or more aspects of the present disclosure, an ablation catheter includes: a slender structure configured to be at least partially inserted into a patient's body, the slender structure including a metal element, the metal element including a plurality of conductive metal wires, the plurality of conductive metal wires including a polymer-coated portion and an exposed metal portion; and a plurality of electrodes disposed at a distal portion of the slender structure, wherein at least one electrode of the plurality of electrodes and the exposed metal portion are configured to provide a current path for at least one of pulsed field ablation or sensing.

[0007] In another example, a method includes providing an elongated structure comprising a metallic element comprising a plurality of conductive metal wires having a polymer coating disposed thereon; removing at least a portion of the polymer coating from a portion of the plurality of conductive metal wires to produce a polymer-coated portion and an exposed metallic portion; and disposing a plurality of electrodes at a distal portion of the elongated structure, wherein at least one of the plurality of electrodes and the exposed metallic portion are configured to provide a current path for at least one of pulsed field ablation or sensing.

[0008] The details of one or more aspects of the present disclosure are set forth in the following drawings and description. Other features, objects, and advantages of the technology described in the present disclosure will be apparent from the description and drawings, as well as from the claims. It should be understood in the present disclosure that the term "sensing" is used to refer to a range of applications, including but not limited to cardiac electrical signals such as myocardial cell depolarization potentials, local electrical tissue impedance values, voltage measurements of current passing through the body for positioning and navigation purposes, and measurements of electromagnetic transmission signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1A to Figure 1B is a conceptual diagram illustrating an exemplary system for delivering ablation therapy according to one or more aspects of the present disclosure.

[0010] Figure 2 is a block diagram illustrating an exemplary controller of an ablation system according to one or more aspects of the present disclosure.

[0011] FIG. 3A to FIG. 3C is a conceptual diagram illustrating an example of an ablation catheter having an expandable structure in accordance with one or more techniques of the present disclosure.

[0012] FIG. 4A to FIG. 4D is a conceptual diagram illustrating an example catheter having a mechanically expandable structure, in accordance with one or more techniques of the present disclosure.

[0013] Figure 5 is a conceptual diagram of a portion of another example catheter in accordance with one or more techniques of the present disclosure.

[0014] FIG. 6A to FIG. 6E is a conceptual diagram illustrating a portion of an exemplary metal element according to one or more aspects of the present disclosure.

[0015] Figure 7 is a conceptual diagram illustrating an exemplary metal element according to one or more aspects of the present disclosure.

[0016] Figure 8 is a flow chart illustrating a technique for manufacturing an ablation catheter according to one or more aspects of the present disclosure. DETAILED DESCRIPTION

[0017] An ablation catheter may include an elongated structure or shaft having a metal element, such as a metal braid (which may also be referred to as a metal fabric or metal mesh) or a plurality of metal coils, which may provide the catheter with a level of kink resistance, effective torque transfer, and flexibility so that the catheter does not kink when inserted into or advanced in the patient's anatomy. Such a metal element may include a polymer coating to provide insulation to or within the metal element. However, even with a polymer coating, such a metal element may act to short-circuit the electric field generated by the electrode of the ablation catheter, particularly when the ablation catheter is operating at a relatively high voltage. In addition, when constructing such a catheter, crimping, swaging, or welding the electrode to the surface of the catheter may cause the electrode to short-circuit the underlying metal element.

[0018] Disclosed herein is technology that exploits the presence of such a metal element in an ablation catheter. For example, a portion of the metal element may have a polymer coating that is partially or completely removed so as to expose the portion of the metal element to the surrounding environment. The portion of the metal element having the polymer coating that is partially or completely removed may be referred to herein as an "exposed metal portion." The exposed metal portion of the metal element may be used as an electrode. For example, the exposed metal portion may be used as a return electrode for ablating tissue or for sensing current. By using the exposed metal portion as a return electrode, current can safely flow from the patient's body to a pulse generator. Alternatively, an electrode may be attached to the exposed metal portion of the metal element, and the exposed metal portion of the metal element may be used as a conductor for the electrode.

[0019] Figure 1A to Figure 1B 1 is a conceptual diagram illustrating an exemplary system for delivering ablation therapy according to one or more aspects of the present disclosure. System 100 includes a catheter 102 and a controller 104. In general, to deliver ablation, a medical practitioner (e.g., a cardiologist, a surgeon, etc.) may insert one or more of catheters 102 into a patient and cause controller 104 to deliver energy (e.g., pulsed field ablation energy) to a target tissue of the patient via catheter 102. In a cardiac patient, ablation may cause lesions in target tissue of the patient's heart that may reduce or stop an arrhythmia. Because ablation is generally intended to cause lesions in the heart, it may be desirable to control the ablation catheter to safely provide a return path to a pulse generator for the current used for ablation.

[0020] The catheter 102 may include an elongated structure 112 that includes a plurality of electrodes 110A-110E (collectively, "electrodes 110"). Although the example of FIG. 1 includes five such electrodes, the catheter 102 may include any number of electrodes. In some examples, each of the electrodes 110 may be configured to selectively function as a cathode or an anode. Thus, an electric field may be generated within the patient's anatomy in a bipolar manner between one or more cathodes and one or more anodes.

[0021] The elongated structure 112 may include a metal element that can provide a certain level of kink resistance and / or effective torque transmission to the catheter 102. The metal element may include a polymer coated portion 120 and an exposed metal portion 118. For example, the exposed metal portion 118 may initially include a polymer coating that can be partially or completely removed, for example, by laser ablation, thermal ablation, or by mechanical force. The exposed metal portion 118 can form a thermocouple and be configured to operate as an electrode (such as a return electrode) during the delivery of pulsed field ablation therapy. For example, one or more of the electrodes 110 can be electrically coupled to a first terminal of the controller 104 (e.g., via conductor 114), and the exposed metal portion 118 can be electrically coupled to a second terminal of the controller 104 (e.g., via conductor 116), the second terminal having a polarity opposite to the first terminal. In the example of FIG. 1, the first terminal is positive and the second terminal is negative. It should be understood that the first terminal can be negative and the second terminal can be positive, or the first terminal and the second terminal can alternate polarity so that when one terminal is positive, the other terminal is negative. In some examples, the exposed metal portion 118 can be electrically coupled to ground instead of being coupled to the second terminal of the controller 104. In some examples, one or more of the electrodes 110 can be electrically coupled to the second terminal of the controller 104 or also electrically coupled to ground. The conductors 114 and 116 can extend through the handle (not shown) of the catheter 102 so that they can be easily connected to the controller 104.

[0022] In some examples, the metal element can include multiple conductive wires extending together side by side, such as a tight corkscrew. In some examples, the metal element can include conductive wires that cross each other as a braid. In some examples, the polymer filaments can be braided with multiple wires in the metal element of the elongated structure 112. Further discussion of exemplary metal elements is later in this disclosure with respect to FIG. 6A to FIG. 6E conduct.

[0023] Manufacturers of such ablation catheters can laser ablate, thermally ablate, or mechanically remove the polymer coating from the metal element to make a portion of the metal element an electrode. In some examples, manufacturers can employ computer vision systems to help ablate the polymer coating from the metal element so as to more accurately remove only the desired amount of polymer coating in the desired location. By moving the location of the ablation, different electric fields for ablation can be generated. In this way, manufacturers can relatively easily manufacture ablation cathodes with different ablation properties.

[0024] When delivering pulsed field ablation therapy, the exposed metal portion 118 can be used as an electrode. In some examples, the exposed metal portion 118 can include a plurality of exposed conductive wires, such as exposed wire 122. The plurality of exposed conductive wires can provide built-in redundancy because each of the plurality of exposed conductive wires can be electrically coupled together due to the removal of the polymer coating. For example, the exposed metal portion 118 can be coupled to a negative terminal of the controller 104 via conductor 116. The conductor 116 can be electrically coupled to each of the plurality of conductive wires in the exposed metal portion 118, so that if one of the plurality of conductive wires is broken, the conductor 116 can continue to provide an electrical connection to the unbroken conductive wires in the plurality of conductive wires in the exposed metal portion 118. Alternatively or in addition, an additional one or more of the plurality of conductive wires in the exposed metal portion 118 can have an independent conductor connection back to a second terminal or similar polarized terminal of the controller 104. In some examples, each of the multiple conductive wires of the exposed metal portion 118 can be used as a separate electrode. For example, the polymer coating between different wires of the multiple conductive wires may not be removed, and the polymer coating on the outer surface or a portion of the outer surface of one or more of the multiple conductive wires may be removed, thereby maintaining insulation between the wires, but exposing the metal of these wires so that these wires can be used individually as electrodes. The exposed metal portion 118 can be approximately 10 mm to 30 mm long and located a few millimeters proximal to the ablation electrode (such as electrode 110). In some examples, after creating the exposed metal portion 118, the manufacturer can apply an insulating coating to a portion of the exposed metal portion 118 to facilitate focusing the electric field in a desired manner.

[0025] In some examples, a portion of elongated structure 112 may have a polymer coating partially or completely removed on a metal element, and an electrode may be attached to the metal element over the exposed metal of the metal element. For example, as shown in FIG. 1 (indicated by dashed lines), the polymer coating on the conductive wire of the metal element may be partially or completely removed at the location of electrode 110C and electrode 110D. Electrodes 110C and 110D may then be crimped, swaged, welded (e.g., laser welded), or otherwise attached to the exposed metal.

[0026] As can be seen, the catheter 102 includes an electrode 110 on a distal portion of an elongated structure 112. In the example of FIG. 1, the electrodes 110A and 110B are positively charged using the controller 104. The elongated structure 112 may include a metal element that may include a polymer filament and a metal coil (e.g., a conductive wire) or may include a metal braid of a conductive wire. The exposed metal portion 118 has a polymer coating that is removed, such as by laser ablation, thermal ablation, or mechanical force, to leave at least a portion of the metal coil or metal braid exposed to the surrounding environment. In some examples, the elongated structure 112 may be mechanically coupled to a lever in a handle (not shown) that allows the position of the exposed metal portion 118 to be adjusted relative to the distal fixed electrode and / or the density of the exposed metal portion 118 to be adjusted. For example, the lever may compress the coil or braid together or stretch the coil or braid apart. The exposed metal portion 118 may be connected to the negative terminal of the controller 104 via a conductor 116. Applying a voltage between the electrodes (e.g., electrode 110A and electrode 110B) allows a current to flow between the electrodes and the exposed metal portion 118 of the elongated structure 112, thereby generating an electric field. The electric field can ablate target tissue of the patient's anatomical structure. In some examples, the strength of the electric field can be adjusted by moving the position of the exposed metal portion, for example, by a lever in the handle.

[0027] The catheter 102 may generally include features that enable the catheter 102 to be inserted into the patient and to navigate to the target tissue site. In some examples, the catheter 102 may include a molded polymer insert configured to reduce or eliminate sharp edges to facilitate insertion and advancement of the catheter 102 into the patient's anatomical structure. The elongated structure 112 may include a distal portion 106 and a proximal portion 108. The electrode 110 may generally be positioned at the distal portion 106, and the proximal portion 108 may be connected to the controller 104. The electrode 110 may have any suitable geometry. Exemplary geometries of the electrode 110 include, but are not necessarily limited to, a circular (e.g., annular) electrode surrounding the body of the lead, a C-shaped electrode partially surrounding the body of the lead, electrodes of other curved shapes, pigtail-shaped electrodes, spiral-shaped electrodes, conformable electrodes, hoop-shaped electrodes, segmented electrodes (e.g., electrodes disposed at different circumferential positions around the lead, rather than a continuous annular electrode), and any combination thereof (e.g., annular electrodes and segmented electrodes). In some examples, where one or more of the electrodes 110 are spiral, one or more of the electrodes 110 may be a fixed pitch spiral shape, a variable pitch spiral shape, or a variable diameter spiral shape. The electrode 110 may be made of nitinol, copper, stainless steel, or other conductive metal materials. In some examples, to better deliver therapeutic high voltage pulses, the electrode 110 may be coated or coated with a suitable metal surface, such as platinum, platinum-iridium alloy, tantalum, gold, nitride (e.g., titanium nitride, tantalum nitride, palladium nitride, or rhodium nitride) and / or the like. In some examples, the electrode 110 may be laser cut from a single metal tube.

[0028] The electrodes 110 may be axially distributed along the longitudinal axis LA of the elongated structure 112. The elongated structure 112 may include conductors, such as conductors 114 and 116, configured to carry electrical signals between the electrodes 110 and the controller 104. In some examples, the elongated structure 112 may include separate conductors for each electrode in the electrodes 110 and for the exposed metal portion 118. For example, in the example of FIG. 1 where the electrode 110 includes five electrodes 110 and exposed metal portions 118, the elongated structure 112 may include six separate conductors. In this way, the elongated structure 112 may enable each electrode in the electrodes 110 and the exposed metal portion 118 to be driven with different signals from the controller 104. In other examples, multiple electrodes in the electrodes 110 and / or the exposed metal portion 118 may share a common conductor. For example, electrodes 110C and 110D may be connected to the same (e.g., common) conductor. While such a common conductor arrangement may reduce electrode flexibility (eg, because electrodes connected to the common conductor may be driven with the same signal), such an arrangement may reduce manufacturing complexity and / or cost and may increase the structural flexibility of the catheter 102 .

[0029] like Figure 1A As shown in , electrode 110 may include a tip electrode (e.g., electrode 110A), which may be a ring electrode having a "cap" covering at least a portion of the tip of the elongated structure 112. In some examples, the tip electrode may be beveled or otherwise rounded (e.g., to enable catheter 102 to more easily pass through the patient's anatomy). Electrode 110 may include a tip ring electrode (e.g., electrode 110B) adjacent to the tip electrode. The tip ring electrode may be separated from the tip electrode (axially along the LA). Electrode 110 may include one or more ring electrode pairs. A ring electrode pair may include two adjacent closely spaced electrodes in electrode 110. For example, in Figure 1A In the example of , electrodes 110C and 110D can form a first annular electrode pair. Generally speaking, the first annular electrode pair (i.e., electrodes 110C and 110D) can be accompanied by one or more additional electrodes. The one or more additional electrodes may include any combination of annular electrode pairs, coil electrodes (e.g., electrodes including a conductor spirally wrapped around the elongated structure 112), or electrodes of any other shape.

[0030] exist Figure 1A In the example of FIG. 1 , electrode 110 is shown as having a larger diameter than elongated structure 112. In some examples, one or more of electrodes 110 may have a diameter that is substantially equal to the diameter of elongated structure 112. For example, electrode 110 may be recessed within elongated structure 112 such that the combination produces a relatively smooth outer surface.

[0031] The controller 104 may include an energy generator configured to provide electrical pulses to the electrode 110 via conductors, such as the conductors 114 and 116, to perform an ablation procedure on cardiac tissue or other tissue within the patient's body, such as kidney tissue, airway tissue, and organs or tissue within the cardiac space or pericardial space. For example, the energy generator may be configured and programmed to deliver a pulsed high voltage electric field suitable for achieving a desired pulsed, high voltage ablation (referred to as "pulsed field ablation" or "pulsed electric field ablation").

[0032] Figure 1BThe catheter 102 is depicted in a compressed position. For example, the elongated structure 112 can be mechanically coupled to a lever in the handle (not shown) that allows the position of the exposed metal portion 118 to be adjusted relative to the distal fixed electrode and / or the density of the exposed metal portion 118 to be adjusted. For example, the lever can compress the conductive wires of the exposed metal portion 118 together or stretch the conductive wires of the exposed metal portion apart. In this example, the conductive wires of the exposed metal portion 118 have been compressed together. For example, along the longitudinal axis LA of the elongated structure 112, the distance between the conductive wires of the exposed metal portion 118 (such as the exposed wire 122 and other wires) is about 1 / 4 of the distance between the exposed metal portion 118 and the distal fixed electrode. Figure 1B can be compared with Figure 1A Closer together.

[0033] According to the technology of the present disclosure, an ablation catheter includes a slender structure, which is configured to be at least partially inserted into an organ of a patient, the slender structure includes a metal element, the metal element includes a metal braid or a plurality of metal coils, the metal braid or the plurality of metal coils include a plurality of conductive metal wires, the plurality of conductive metal wires include a polymer-coated portion and an exposed metal portion, wherein the exposed metal portion is configured to provide an electrical return path to a pulsed field ablation generator; and a plurality of electrodes disposed at a distal portion of the slender structure.

[0034] According to the technology of the present disclosure, a method includes: providing a slender structure, the slender structure including a metal element, the metal element including a metal braid or a plurality of metal coils, the metal braid or the plurality of metal coils including a plurality of conductive metal wires, the plurality of conductive metal wires having a polymer coating disposed thereon; removing at least a portion of the polymer coating from a portion of the plurality of conductive metal wires to produce a polymer-coated portion and an exposed metal portion, wherein the exposed metal portion is configured to provide an electrical return path to a pulsed field ablation generator; and disposing a plurality of electrodes at a distal portion of the slender structure.

[0035] In some examples, one or more exposed metal portions of the elongated structure 112 can be used as sensing electrodes to sense the impedance of the body, thereby determining the position of the elongated structure 112 within the patient's body. For example, one or more exposed metal portions of the system 100 can be used as electrodes so that the controller 104 can sense the voltage level of one or more currents transmitted from one or more body surface patch electrodes (also not shown) through the body cavity to the one or more exposed metal portions. For example, multiple constant current signals (e.g., three) can be driven through the patient's body via multiple patch electrodes, which can be deployed in orthogonal pairs (e.g., a total of six patch electrodes). The sensing element can sense a voltage drop according to the position within the body, because the impedance of body tissue and blood can affect the voltage measurement of the sensing element. The controller 104 can then use such sensed voltage levels to determine the position of the sensing element (e.g., exposed metal portion) and the associated device structure in the patient's body.

[0036] In some examples, for example, when exposed metal portion 118 includes at least one coil, system 100 can sense the emitted magnetic field to determine the location of elongated structure 112 within the body. In some examples, multiple exposed metal portions (such as exposed metal portion 118) can be used as sensors for determining the position in the body. For example, elongated structure 112 can include multiple exposed metal portions, such as at the distal end of elongated structure 112 and at other locations along elongated structure 112. The sensor can sense the current from such exposed metal portions to determine the position of elongated structure 112 in the body.

[0037] Although not shown, the system 100 may include one or more sensors to monitor operating parameters (such as temperature, delivered voltage, etc.) through the medical system 100, and to measure and monitor one or more tissue characteristics (such as electrogram waveforms, monophasic action potentials, tissue impedance, etc.), in addition to monitoring, recording, or otherwise transmitting measurements or conditions of the surrounding environment within the energy delivery device or other components of the system 100 or at the distal portion of the energy delivery device. The sensors may communicate with the controller 104 to initiate or trigger one or more alarms or ablation energy delivery modifications during operation of the energy delivery device. In some examples, such sensors may be part of the controller 104.

[0038] Figure 2 is a block diagram illustrating an exemplary controller of an ablation system according to one or more aspects of the present disclosure. Figure 2 The controller 200 may be an example of the controller 104 of FIG. 1 . Figure 2As shown in , the controller 200 may include a positive terminal (+) 212 , a negative terminal (−) 214 , an energy generator 202 , a processing circuit 204 , a user interface 206 , and a storage device 208 .

[0039] The positive terminal 212 may be coupled to the energy generator 202 and may be configured to attach to the conductor 114 ( FIG. 1 ) so as to conduct electricity between the energy generator 202 and the conductor 114. The negative terminal 214 may be coupled to the energy generator 202 (or alternatively to ground) and may be configured to attach to the conductor 116 ( FIG. 1 ) so as to conduct electricity between the conductor 116 and the energy generator 202. The energy generator 202 may be configured to control the electrode 110 and / or the exposed metal portion 118 ( FIG. 1 ) of the catheter 102 so as to provide electrical pulses to the electrode (e.g., the electrode 110) to perform an electroporation procedure or other ablation procedure on cardiac tissue or other tissue within the patient's body (such as renal tissue, airway tissue, and organs or tissue within the cardiac space or pericardial space). For example, the energy generator 202 may be configured and programmed to deliver a pulsed high voltage electric field suitable for achieving a desired pulsed, high voltage ablation (referred to as “pulsed field ablation” or “pulsed electric field ablation”). Although in Figure 2 In the example of the controller 200, a single energy generator is shown, but the energy generator 202 is not limited thereto. For example, the controller 200 may include multiple energy generators, each of which is capable of generating ablation signals in parallel. In some examples, the controller 200 may include different types of energy generators, such as a pulsed field energy generator, a radio frequency energy generator, and / or a cryogenic energy generator. In some examples, the cryogenic energy generator may be part of the catheter 102 and electrically controlled by the processing circuit 204.

[0040] The processing circuit 204 may include one or more processors, such as any one or more of the following: a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a discrete logic circuit, or any other processing circuit configured to provide the functionality attributed to the processing circuit 204, which may be embodied herein as firmware, hardware, software, or any combination thereof. The processing circuit 204 controls the energy generator 202 to generate signals according to various settings 21o that may be stored in the storage device 208.

[0041] The storage device 208 may be configured to store information within the controller 200 during operation. The storage device 208 may include a computer-readable storage medium or a computer-readable storage device. In some examples, the storage device 208 includes one or more of a short-term memory or a long-term memory. The storage device 208 may include, for example, a random access memory (RAM), a dynamic random access memory (DRAM), a static random access memory (SRAM), a magnetic disk, an optical disk, a flash memory, or various forms of electrically programmable memory (EPROM) or electrically erasable programmable memory (EEPROM). In some examples, the storage device 208 is used to store data indicating instructions to be executed, for example, by the processing circuit 204.

[0042] The user interface 206 may include buttons or a keypad, lights, a speaker / microphone for voice commands, and / or a display such as a liquid crystal (LCD), a light emitting diode (LED), or an organic light emitting diode (OLED). The user interface 206 may be configured to receive input from a clinician, such as selecting settings from the settings 210 for use during an ablation therapy session. In some examples, the display may be configured to display information about the ongoing ablation therapy session, such as patient parameters or other information that may be useful to the clinician.

[0043] FIG. 3A to FIG. 3C is a conceptual diagram illustrating an example of an ablation catheter having an expandable structure in accordance with one or more techniques of the present disclosure. Figure 3A An exemplary catheter 302 having an inflatable structure 320 in an unexpanded (or deflated) state is depicted. In the unexpanded state, the catheter 302 can be more easily inserted into the patient's anatomical structure than when the inflatable structure 320 is in an expanded state. For example, the inflatable structure 320 may include a balloon. The balloon may be filled with a gas or liquid via tubing (not shown) by the controller 104 or a pump. Electrodes 310A, 310B, 310C, and 310D (collectively referred to as "electrodes 310") are shown attached to the outer surface of the inflatable structure 320. By expanding the inflatable structure 320, a clinician can position one or more of the electrodes 310 at an appropriate location and at a distance from a target tissue within the patient's anatomical structure to perform ablation therapy on the target tissue. As can be seen, the electrodes 310 are offset from each other on the surface of the inflatable structure 320 so as to minimize the size of the catheter 302 when the inflatable structure 320 is in an unexpanded state. Exposed metal portion 318 may represent an example of exposed metal portion 118 of FIG. 1 , and may be used as an electrode, such as a return electrode.

[0044] Figure 3B Different views of electrodes (labeled E), which may be examples of electrodes 310, are depicted in an offset position. Figure 3B The electrodes may be coupled to conductors, such as conductor 322, which may be configured to conduct electricity to or from controller 104 of FIG. 1.

[0045] Figure 3C The catheter 302 is depicted with the expandable structure 320 in the expanded position. As can be seen, when the expandable structure 320 is in the expanded state, the electrode 310 is larger than when it is in the unexpanded state ( Figure 3A ) is further away from the expandable structure 312 and, more likely, closer to the patient's tissue when positioned within the patient's anatomy.

[0046] FIG. 4A to FIG. 4D is a conceptual diagram illustrating an exemplary catheter having an expandable mechanical structure according to one or more techniques of the present disclosure. FIG. 4A to FIG. 4C In some examples, catheter 402 may include an expandable mechanical structure that may be similar in appearance to a cocktail umbrella. The expandable mechanical structure may be configured to be manipulated from a neutral or axial configuration to an upright or semi-upright configuration by a mechanical device, lever, etc., which may be accessed via a handle (not shown) of catheter 402. In some examples, catheter 402 may include a core (in FIG. 4A to FIG. 4C ), the core may extend axially through the catheter 402, thereby providing some reinforcement properties to facilitate advancement of the catheter 402 through the patient's anatomical structure. This expandable mechanical structure may be made of any suitable material, such as nitinol.

[0047] Catheter 402 may include a plurality of electrodes, such as electrode 410A. FIG. 4A to FIG. 4C In an example of, the plurality of electrodes can be generally spherical in shape and can be welded, crimped, swaged, formed on an electrode arm (such as electrode arm 426A), or otherwise coupled to the electrode arm. The catheter 402 can also include an exposed metal portion 418, which can be an example of the exposed metal portion 118 (FIG. 1) or the exposed metal portion 318 (FIG. 3). Figure 4A and Figure 4B An example of an electrode arm of such a mechanical structure and a deployment mechanism for such an electrode arm are depicted. Figure 4AIn the example of , the exposed metal portion 418 is shown as having conductive wires that cross each other, rather than the spiral conductive wires of the exposed metal portion 118 or the exposed metal portion 318. Electrode 410A is disposed on an electrode arm 426A. Electrode arm 426A is shown in a semi-contracted or unexpanded state. In some examples, when electrode arm 426A is in a fully retracted or unexpanded state, electrode arm 426A can be relatively parallel to the body of catheter 402 so as to maintain a relatively low profile when in the retracted or unexpanded state. Electrode arm 426A can be mechanically coupled or in contact with deployment arm 424. Deployment arm 424 can be mechanically coupled or in contact with outcropping 422. Outcropping 422 can be moved by a clinician via a handle (not shown) of catheter 402 by a mechanical device or lever. For example, the outcropping can be coupled to a mechanical deployment device. By Figure 4A The detent 422 is moved in the direction indicated by the arrow shown in FIG. 4 , and the detent 422 pushes the deployment arm 424, which causes the electrode arm to be deployed, thereby moving the electrode 410A away from the main body of the catheter 402, as shown in FIG. Figure 4B as shown in .

[0048] Figure 4C A view of the catheter 402 is depicted in an expanded state. Figure 4C In the example of FIG. 4 , catheter 402 may include a plurality of electrodes, such as electrodes 410A, 410B, and 410C (collectively referred to as “electrode 410”). Each electrode in electrode 410 may be disposed on a corresponding electrode arm, such as electrode arms 426A, 426B, and 426C (collectively referred to as “electrode arms 426”). Figure 4C 4, but another electrode arm may be located on the opposite side of the electrode arm 426B on which the electrode is disposed. Figure 4C Each of the electrode arms 426 may be connected to a corresponding deployment arm (in Figure 4C not shown), such as FIG. 4A to FIG. 4B The extended arm 424 is coupled or in contact with the exposed metal portion 418. The exposed metal portion 418 is shown and can be configured as an electrode, such as a return electrode.

[0049] In some examples, catheter 402 may include sheath 430. Sheath 430 may be configured to make it easier to insert and advance catheter 402 into the patient's anatomical structure, and to protect the patient during the insertion and advancement of catheter 402 into the patient's anatomical structure. For example, sheath 430 may cover the distal end 432 of elongated structure 412. In some examples, during the insertion and advancement of catheter 402 into the patient's anatomical structure, sheath 430 may cover one or more electrodes, such as electrode 410 or other electrodes (not shown). In such examples, sheath 430 may be coupled to a mechanical device or lever in the handle of catheter 402, and the clinician may move the mechanical device or lever to push sheath 430 distally, thereby exposing the electrode once the clinician has navigated catheter 402 to the desired position with the patient's anatomical structure. Once the clinician delivers ablation therapy via catheter 402, the clinician may utilize a mechanical device or lever to return the position of sheath 430 to cover the electrode.

[0050] In some examples, when the catheter 402 is in an unexpanded state, rather than including a deployment arm and an exposed portion, the electrode arm 426 can be biased to be in an expanded state and the sheath 430 can cover the electrode arm 426, thereby maintaining the electrode arm 426 close to the elongated structure 412 of the catheter 402. The sheath 430 can be coupled to a mechanical device or lever within the handle of the catheter 402, which the clinician can move to push the sheath 430 distally, thereby deploying the electrode arm to the expanded state. When the ablation procedure is completed, the clinician can retract the sheath proximally to re-cover the electrode arm 426 and return the catheter 402 to the unexpanded state via the mechanical device or lever. In some examples, the expandable mechanical structure is non-isodiametric.

[0051] Figure 4D A view of catheter 452 is depicted in an expanded state. Catheter 452 may be similar to FIG. 4A to FIG. 4C The catheter 402 is different from the electrode arms 476A, 476B and 476C (collectively referred to as "electrode arms 476") that can be connected to FIG. 4A to FIG. 4C The electrode arms 426 are articulated in different directions. In this way, in the event of a failure of the deployment and / or retraction device of the catheter, removal of the catheter 452 from the patient can be performed more easily.

[0052] Figure 55 is a conceptual diagram of a portion of another exemplary catheter according to one or more techniques of the present disclosure. Catheter 502 may include a plurality of electrodes, such as electrodes 510A and 510B (collectively referred to as "electrode 510"). Electrode 510 may be curved in shape, such as similar to the letter "C". Although electrode 510 is shown as being curved in shape, alternatively, electrode 510 may be pigtail-shaped or spiral-shaped. In some examples, where one or more of electrodes 510 are spiral-shaped, one or more of electrodes 510 may be fixed pitch spiral-shaped, variable pitch spiral-shaped, or variable diameter spiral-shaped. Each of electrodes 510 may partially surround an expandable structure (not shown) of catheter 502. For example, electrode 510 may be laser cut from a single metal tube. Such a metal tube may contain nitinol, copper, stainless steel, or another conductive material. Conductor 540 may similarly be cut from the same single metal tube and electrically coupled to electrode 510. In some examples, conductor 540 may take the form of a ribbon. By cutting the electrodes 510 and conductors 540 from a single metal tube, the catheter 502 can have increased structural rigidity and thereby facilitate introduction and advancement of the catheter 502 into the patient's anatomy as compared to if the electrodes and conductors were manufactured separately and then coupled together. This increased structural rigidity can also help maintain the spacing of the electrodes as the catheter 502 is introduced into and advanced within the patient's anatomy.

[0053] For example, a manufacturer may cut a series of slotted C-shaped electrodes (e.g., electrode 510) connected by a ribbon (e.g., conductor 540) from a single metal tube. Such a metal tube may be a nitinol tube, a copper tube, or another metal or alloy tube. In some examples, after cutting the electrode 510 and the conductor 540 from a single metal tube, the conductor 540 may be coated with a polymer coating. In some examples, the polymer coating may include any of the following: polyimide, nylon, PTFE (polytetrafluoroethylene), FEP (fluorinated ethylene propylene), ETFE (ethylene tetrafluoroethylene), PVDF (polyvinylidene fluoride), polyurethane-nylon, cross-linked high-density polyethylene or polypropylene, soluble imide (SI) polyimide (formerly known as Genymer, Genymer SI), LarC-SI, Pyre-ML polyimide, and / or the like. In some examples, the polymer coating may be formed of a hydrolytically stable polyimide (such as SI polyimide) or other relatively high dielectric strength polymer to insulate the conductor and allow the electric field to be generated by the electrode 510. It should be noted that because the electrodes 510 and conductors 540 can be cut from the same metal tube prior to coating the conductors 540, electrical conductivity can be maintained between the electrodes 510 and the conductors 540. The ribbon wire provides structural rigidity to maintain the spacing of the electrodes when external loads are applied due to movement of the catheter within the body.

[0054] FIG. 6A to FIG. 6E is a conceptual diagram illustrating a portion of an exemplary metal element according to one or more aspects of the present disclosure. Fig. 6A A longitudinal or axial view of a metal element 600 is depicted. Metal element 600 may be an example of the metal element of FIG. 1 . Metal element 600 may include one or more conductive metal wires, such as wire 602, which may include a conductive material, such as copper or a copper alloy. Wire 602 may initially include a polymer coating that may surround the diameter of wire 602 along at least a portion of the length of wire 602 to provide electrical insulation to wire 602. For example, the polymer coating may include one or more materials, such as those described above. Fig. 6A Each of the conductive wires with diagonal fill shown in FIG. 6 may be similar to wire 602 or may be a portion of wire 602, as wire 602 may surround a core element ( Fig. 6A ) is wound around or suspended in a spiral manner on a substrate ( Fig. 6A In some examples, the substrate may be used as a polymer coating for the filament 602. At least a portion of the polymer coating and / or the substrate may be removed via laser ablation, thermal ablation, or mechanical force to expose at least a portion of the conductive material of the filament 602 to the surrounding environment.

[0055] Wire 604 may include the same conductive material as wire 602 or a different conductive material than wire 602. For example, wire 604 may include constantan. Wire 604 may initially include a polymer coating that may surround the diameter of wire 604 along at least a portion of the length of wire 604 to provide electrical insulation to wire 604. For example, the polymer coating may include a polymer such as poly(p-xylene) N, polyethylene naphthalate (PEN), or other relatively high dielectric strength polymers. Fig. 6A Each of the wires shown in the figure with a square or cross fill can be similar to wire 604 or can be a part of wire 604, because wire 604 can be wound around a core element or suspended in a spiral manner in a substrate. In some examples, the substrate can be used as a polymer coating for wire 604. After laser ablation, at least a portion of the polymer coating and / or substrate can be ablated to expose at least a portion of the conductive material of wire 604 to the surrounding environment. Although shown as extending substantially parallel to wire 602, in some examples, wire 604 can extend in a direction different from wire 602. In some examples, wire 604 can form a braid or fabric with wire 602 by extending in different directions and weaving behind and in front of wire 602.

[0056] Metal element 600 may also include one or more polymer fibers, such as polymer fibers 606. Polymer fibers 606 may include monofilament fibers. The properties of polymer fibers 606 may include relatively high tensile strength, relatively high tensile modulus, relatively high melting temperature or softening temperature. In some examples, polymer fibers 606 may include aromatic polyesters (such as "Vectran" or PEN), nylon, PEEK (polyetheretherketone), polyparaxylene N, or other relatively high tensile strength polymers. Fig. 6A Each of the polymer fibers shown without filling in 604 may be similar to polymer fibers 606 or may be a portion of polymer fibers 606, as polymer fibers 606 may be wound around a core element or suspended in a spiral manner in a substrate. In some examples, polymer fibers 606 may be wound around a core or suspended in a substrate in a different direction than filaments 602 and 604. In some examples, polymer fibers 606 may form a braid or fabric with filaments 602 and 604 by weaving behind and in front of filaments 602 and 604.

[0057] Figure 6B (which may not be drawn to scale) depicts a cross-section of a metal element 600 before removing a polymer coating of at least a portion of the metal element 600. The metal element 600 may include a core element 610, one or more conductive metal wires (such as wire 602 and wire 604), and one or more polymer fibers (such as polymer fiber 606). The core element 610 may include a hollow core or lumen through which a mechanical control wire, a conductive wire, a guide wire, and / or the like may pass. For example, one or more conductive metal wires and one or more polymer fibers may be wound around the core element 610. Alternatively or in addition, one or more conductive metal wires and one or more polymer fibers may be suspended in a substrate 608. The core element 610 and / or the substrate 608 may be made of any suitable material. In some examples, the substrate 608 includes a polymer, such as a polyether block amide, commonly referred to as PEBAX or Vestamide. In some examples, substrate 608 is configured to act as a polymer coating for filament 602 and / or filament 604. Alternatively or in addition, filament 602 and / or filament 604 may have a separate polymer coating (in Figure 6B The polymer coating may be a relatively high melting temperature thermoplastic or an additional cured cross-linked thermosetting polymer that will remain stable when a lower melting temperature thermoplastic, polyether block amide sheath is extruded over the braid. For example, the additional polymer coating may be a SI polyimide coating.

[0058] In some examples, the diameter of the core 610 can be about 0.080 inches. In some examples, the plurality of conductive wires can include five wire pairs, each wire pair having a diameter of about 0.002 inches. In some examples, the metal element 600 can include an outer shell 612. In some examples, the outer shell can have an outer diameter of about 0.105 inches and an inner diameter of about 0.095 inches.

[0059] Figure 6C Depicted is a cross section of metal element 600 after removing a portion of substrate 608. As can be seen, filament 602 and filament 604 are now partially exposed to the surrounding environment. As such, filament 602 and / or filament 604 can now be used as an electrode, such as a return electrode.

[0060] Fig.6D Wire 602 is depicted prior to removal of at least a portion of the polymer coating. Fig.6D In the example of FIG. 6 , wire 602 includes a conductive metal core 622 and a polymer coating 620. The polymer coating 620 can be configured to act as an insulator for wire 602, thereby making the conductive metal core 622 insulated from other wires (such as wire 604 ( FIG. 6A to FIG. 6C ))insulation.

[0061] Fig. 6E Wire 602 is depicted after removing a portion of polymer coating 620. As can be seen, the right portion of polymer coating 620 has been removed, exposing conductive metal core 622 to the surrounding environment on the right side of wire 602. In some examples, rather than removing a portion of polymer coating 620, all of polymer coating 620 may be removed.

[0062] Figure 7 is a conceptual diagram illustrating an exemplary metal element according to one or more aspects of the present disclosure. Figure 7 The metal element 700 may include a plurality of conductive metal wires including a polymer coated portion 702 and an exposed metal portion 710. The polymer coated portion 702 may include wires coated with a polymer coating as discussed herein. The polymer coating on portions of the conductive metal wires may be removed, such as by laser ablation, thermal ablation, or mechanical force, to produce or form the exposed metal portion 710.

[0063] An exposed metal portion, such as exposed metal portion 710, may be located at a single location on elongated structure 112 (eg, Figure 1A to Figure 1B ) or at multiple locations (eg, located below electrodes 110C, 110D and located at Figure 1A to Figure 1BIn some examples, as described above, one or more exposed metal portions can be utilized, such as in conjunction with one or more body surface patch electrodes, to determine the location of the exposed metal portions and associated elements of the elongated structure 112 in the patient's body.

[0064] Compared with implementing a system with multiple exposed metal parts, different techniques can be used to implement a system with a single exposed metal part, particularly for a system that can determine the position of the exposed metal part in the patient's body as discussed herein. For example, in order to produce a single exposed metal part 710, all wires (filar) (or multiple filaments) can be exposed simultaneously. For example, in a typical braided elongated structure, 16 can be a typical number of wires, and all 16 wires can be exposed to laser ablation, thermal ablation, mechanical force, etc. at the same time. These now exposed wires can be joined (e.g., electrically coupled) to a common conductor in the handle (not shown) of the system 100, which terminates at a pin in a connector that connects the elongated structure 112 to the conductor 114 or 116. In such examples, insulation (e.g., polymer coating) between separate wires may not exist. For example, the polymer coating can be completely (or almost completely) removed from the portion of the wire in the exposed metal part 710, or the polymer coating on the conductive metal wire before producing the exposed metal part 710 can have little or no polymer coating between separate wires. For example, the polymer coating may have been deposited on the conductive wires while the conductive wires were arranged in a braided pattern such that minimal or no polymer coating is deposited between the conductive wires.

[0065] In some examples, at least at the location of the exposed metal portion (e.g., exposed metal portion 118), the braiding angle 722 relative to the horizontal axis 720 is relatively large, so as to expose a relatively large surface area of ​​metal in a relatively small amount of slender structure exposed length along the horizontal axis 720. For example, the braiding angle 722 can be greater than 45 degrees. The achievable braiding angle will be affected by the size of the wire (e.g., the diameter of the circular cross-section wire, the width of the flat wire, etc.) and the diameter of the slender structure 112. For the slender structure 112 of equivalent diameter, the larger the wire, the smaller the achievable braiding angle. Therefore, the braiding angle 722 can be inherently different between different catheter designs.

[0066] Because an acceptable signal-to-noise ratio of the exposed metal portion 710 may be highly desirable, and the overall impedance created by the length and diameter of the filaments of the exposed metal portion 710 may be of concern, an Ag core MP35N material may be used for the metal element 700 because such a material may balance the mechanical properties and resistance of the elongated structure 112. The polymer coating of the polymer coating portion 702 may include LarC-SI (or Genymer) polyimide and / or any of the polymers discussed herein.

[0067] In the case where the system 100 includes multiple exposed metal portions, the following may be performed. First, each of the wires may be isolated from each other with an insulating material that is sufficiently robust to abrasion at the intersections between the wires. This may be more important in any deflectable or highly flexible segment of the elongated structure 112. For example, without such isolation, all exposed wires may be shorted together, and a single "center of mass" point may be determined as the location of the exposed metal portion, such as the midpoint of all exposed locations, which may be undesirable. Second, insulation may be removed from a specific wire at a specific location. For example, a transparent elongated structure or shaft sheath with a separately colored insulation coupled to a visual system and laser ablation may be used to remove insulation from a specific wire. Third, each exposed metal portion 710 may include a sufficient amount of exposed metal to generate an acceptable signal-to-noise ratio, where the noise may come not only from static noise, but also from the environment when the elongated structure 118 may be moving through the ventricle or elsewhere in the patient's body.

[0068] Figure 8 6 is a flow chart illustrating a technique for manufacturing an ablation catheter according to one or more aspects of the present disclosure. A catheter manufacturer may provide an elongated structure including a metal element including a plurality of conductive wires having a polymer coating disposed thereon (800). For example, a manufacturer may manufacture or purchase an elongated structure. The elongated structure may include a metal element 600 (FIG. 6). The metal element 600 may include a metal braid or a plurality of metal coils. The metal braid or the plurality of metal coils may include a plurality of conductive wires, such as wire 602 and wire 604. The plurality of conductive wires may have a polymer coating disposed thereon.

[0069] The manufacturer can remove at least a portion of the polymer coating from a portion of the plurality of conductive metal wires to produce a polymer-coated portion and an exposed metal portion (802). For example, the manufacturer can remove some or all of the polymer coating from a portion of one or more of wires 602 or 604 by laser ablation, thermal ablation, or mechanical force to produce an exposed metal portion, such as exposed metal portion 118 (FIG. 1).

[0070] The manufacturer may provide a plurality of electrodes at the distal portion of the elongated structure, wherein at least one of the plurality of electrodes and the exposed metal portion are configured to provide a current path for at least one of pulsed field ablation or sensing (804). For example, the manufacturer may crimp, swage, weld, or otherwise attach electrode 110 (FIG. 1) at the distal portion of elongated structure 112 (FIG. 1). For example, at least one of the electrodes and the exposed metal portion may be used to generate a pulsed field for ablation. In some examples, the exposed metal portion may provide a return path for current to exit the patient's body to the pulsed field ablation generator.

[0071] In some examples, metal element 600 also includes polymer fibers interwoven between multiple conductive metal wires (e.g., wire 602 and wire 604). In some examples, the multiple conductive metal wires are insulated from each other. In some examples, the multiple conductive metal wires are not insulated from each other at least in the exposed metal portion. In some examples, the metal element includes a braid, and wherein in the exposed metal portion, the braid angle has an angle of at least 45 degrees relative to the horizontal axis of the elongated structure. In some examples, the metal element is configured to be adjustable so as to change the density of the multiple wires within the elongated structure, such as Figure 1B For example, the metal element may be coupled to a mechanical device or lever that a clinician may use via the handle to stretch or compress the elongated element.

[0072] In some examples, the exposed metal portion is a first exposed metal portion located at a first location of the elongated structure, and the manufacturer can remove at least a portion of the polymer coating from the plurality of conductive metal wires at a second location of the elongated structure to produce a second exposed metal portion, the second exposed metal portion configured to conduct electricity to at least one electrode of the plurality of electrodes. The catheter manufacturer can attach (e.g., crimp, swage, weld, or otherwise attach) at least one electrode of the plurality of electrodes to the second exposed metal portion.

[0073] In some examples, the catheter manufacturer may laser cut the plurality of electrodes from the conductive tube into a curved shape, a pigtail shape, or a spiral shape. In some examples, the catheter manufacturer may laser cut a ribbon that is part of the tube and coupled to at least one of the plurality of electrodes. In some examples, the polymer coating comprises polyimide, nylon, PTFE (polytetrafluoroethylene), FEP (fluorinated ethylene propylene), ETFE (ethylene tetrafluoroethylene), PVDF (polyvinylidene fluoride), polyurethane-nylon, cross-linked high-density polyethylene or polypropylene, soluble imide (SI) polyimide (formerly known as Genymer, Genymer SI) or other relatively high dielectric strength polymers.

[0074] In some examples, the catheter manufacturer may attach an expandable structure to the distal portion of the elongated structure. In some examples, the manufacturer may attach at least one of the plurality of electrodes to the expandable structure. In some examples, the expandable structure is configured to expand to move a respective position of at least one of the plurality of electrodes relative to a target tissue in an organ of a patient. In some examples, the expandable structure comprises a balloon or a mechanically contractible structure.

[0075] The techniques described in this disclosure may be implemented at least in part in hardware, software, firmware, or any combination thereof. For example, various aspects of the described techniques may be implemented within a processing circuit that may include one or more processors, including one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs); or any other equivalent integrated or discrete logic circuits; and any combination of such components. The term "processor" or "processing circuit" may generally refer to any of the foregoing logic circuits, alone or in combination with other logic circuits, or any other equivalent circuit. A control unit including hardware may also form one or more processors or processing circuits configured to perform one or more techniques of the present disclosure.

[0076] Such hardware, software, and firmware may be implemented, and various operations may be performed on a coordinated basis within the same device, within a separate device, and / or within, between, or across multiple devices to support the various operations and functions described in this disclosure. In addition, any of the described units, circuits, or components may be implemented together, or independently implemented as discrete but interoperable logic devices. Describing different features as circuits or units is intended to highlight different functional aspects, and does not necessarily imply that such circuits or units must be implemented by independent hardware components or software components. On the contrary, the functions associated with one or more circuits or units may be performed by independent hardware components or software components, or integrated in common or independent hardware components or software components. The processing circuits including one or more processors described in this disclosure may be implemented as fixed-function circuits, programmable circuits, or combinations thereof in various examples. Fixed-function circuits refer to circuits that provide specific functionality using preset operations. Programmable circuits refer to circuits that can be programmed to perform various tasks and provide flexible functionality in executable operations. For example, a programmable circuit may execute software or firmware that causes the programmable circuit to operate in a manner defined by the instructions of the software or firmware. Fixed-function circuits can execute software instructions (e.g., to receive stimulation parameters or output stimulation parameters), but the type of operation performed by the fixed-function circuits is generally immutable. In some examples, one or more of these units may be distinct circuit blocks (fixed-function or programmable), and in some examples, one or more of these units may be integrated circuits.

[0077] The techniques described in the present disclosure may also be embodied or encoded in a computer-readable medium (such as a computer-readable storage medium) containing instructions, which may be described as a non-transitory medium. The instructions embedded or encoded in the computer-readable storage medium may cause a programmable processor or other processor to perform the method, for example, when executing these instructions. The computer-readable storage medium may include a random access memory (RAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, a hard disk, a CD-ROM, a floppy disk, a cassette, a magnetic medium, an optical medium, or other computer-readable medium.

Claims

1. An ablation catheter, the ablation catheter include: an elongated structure configured to be at least partially inserted into a patient, the elongated structure comprising a metallic element comprising a plurality of electrically conductive wires including a polymer-coated portion and an exposed metallic portion; and a plurality of electrodes disposed at a distal portion of the elongated structure, Wherein at least one electrode of the plurality of electrodes and the exposed metal portion are configured to provide a current path for at least one of pulsed field ablation or sensing. 2 . The ablation catheter of claim 1 , wherein the metal element further comprises polymer fibers interwoven between the plurality of conductive wires. 3 . The ablation catheter according to claim 1 , wherein the plurality of conductive wires are insulated from each other. 4 . The ablation catheter according to claim 1 , wherein the plurality of conductive metal wires are not insulated from each other at least in the exposed metal portion.

5. The ablation catheter of any one of claims 1 to 4, wherein the metal element comprises a braid, and wherein in the exposed metal portion, a braid angle has an angle of at least 45 degrees to a horizontal axis of the elongated structure.

6. The ablation catheter of any one of claims 1 to 5, wherein the metal element is configured to be adjustable so as to vary a density of the plurality of wires within the elongated structure.

7. The ablation catheter of any one of claims 1 to 6, wherein the exposed metal portion is a first exposed metal portion at a first location of the elongated structure, and wherein the plurality of conductive wires include: A second exposed metal portion at a second location of the elongated structure is configured to conduct electricity to at least one electrode of the plurality of electrodes, wherein the at least one electrode of the plurality of electrodes is electrically coupled to the second exposed metal portion.

8. The ablation catheter according to any one of claims 1 to 4 or 6 to 7, wherein the plurality of electrodes are laser cut from the conductive tube and are in a meander shape, a pigtail shape, or a spiral shape.

9. The ablation catheter of claim 8, further comprising a ribbon that is part of the conductive tube and is coupled to at least one electrode of the plurality of electrodes.

10. An ablation catheter according to any one of claims 1 to 9, further comprising an expandable structure located on a distal portion of the elongated structure, wherein at least one of the plurality of electrodes is disposed on the expandable structure, and wherein the expandable structure is configured to expand to move a corresponding position of the at least one of the plurality of electrodes relative to a target tissue in the organ of the patient. The ablation catheter of claim 10 , wherein the expandable structure comprises a balloon or a mechanically contractible structure.

12. A method, the method comprising: include: providing an elongated structure comprising a metal element, the metal element comprising a plurality of electrically conductive wires having a polymer coating disposed thereon; removing at least a portion of the polymer coating from a portion of the plurality of electrically conductive metal filaments to produce a polymer-coated portion and an exposed metal portion; as well as disposing a plurality of electrodes at a distal portion of the elongated structure, Wherein at least one electrode of the plurality of electrodes and the exposed metal portion are configured to provide a current path for at least one of pulsed field ablation or sensing.

13. The method of claim 12, wherein the metal element further comprises polymer fibers interwoven between the plurality of conductive metal filaments.

14. A method according to claim 12 or claim 13, wherein the plurality of conductive wires are insulated from each other.

15. The method of claim 12 or claim 13, wherein the plurality of conductive metal wires are not insulated from each other at least in the exposed metal portion.

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