Ablation catheter guide wire

Abstract

A guidewire includes a core member including a proximal portion having a first hardness and a distal portion having a second hardness less than the first hardness. The guidewire also includes an electrical insulator enclosing at least a portion of the proximal portion of the core member and the distal portion of the core member. The electrical insulator includes a material configured to electrically insulate the core member from pulsed field ablation (PFA) energy delivered by the guidewire guided (PFA) catheter. The guidewire also includes an electrode positioned along the distal portion.

Description

[0001] This application claims the benefit of U.S. Provisional Patent Application 63 / 382,842, filed Nov. 8, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present technology relates to ablation catheters. Specifically, various examples of the present technology relate to using an ablation catheter delivery device to assist ablation. 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, laser ablation, radiation, and radiofrequency (RF) ablation.

[0004] Cardiac arrhythmias are a group of conditions that cause an irregular heart rhythm or conduction pattern. Ablation can be used to create a safe and effective lesion or group of lesions at the origin of the arrhythmia or in an area that helps terminate the arrhythmia without causing damage to adjacent structures or surrounding tissue, ideally resulting in the need for no maintenance treatment regimen, such as medications or cardioversion. Summary of the Invention

[0005] The present technology relates to devices, systems, and methods for using an ablation catheter delivery device to assist ablation. The ablation catheter delivery device may include an insulated guidewire configured to be used with a relatively high voltage PFA energy delivery electrode. The guidewire may include one or more of a navigation electrode, a mapping electrode, and / or an ablation electrode.

[0006] Standard guidewires may have very little electrical insulation, and if they should become prolapsed, for example, fold back on themselves and / or on the ablation catheter and be adjacent to the PFA energy delivery electrode, the result may be a short circuit of the high energy transferred between adjacent PFA electrodes. Such short circuits may be undesirable. According to the devices, systems, and techniques herein, the guidewire may be configured to reduce the likelihood of such short circuits and may provide additional features and / or capabilities.

[0007] For example, the guidewire may have a varying stiffness along its length to balance the pushability and flexibility of the guidewire, thereby navigating the guidewire within the patient's body while preventing tissue penetration, such as the blood vessel wall, and preventing electrical shorting of the PFA electrodes. The guidewire may have a varying stiffness along its length to provide sufficient stiffness at the proximal portion for manipulation and navigation of the transition portion, and the distal portion has relatively greater flexibility for improved and relatively non-invasive passage, such as through the vasculature, within the patient's body. The guidewire may include a core that has a first thickness at the proximal portion, and a second and smaller thickness at the distal portion, and a thickness that gradually decreases between the two thicknesses at the transition portion. The core may be insulated within the surrounding dielectric material. The guidewire may include an insulating sheath that surrounds the core and the dielectric material and is configured to house signal lines and / or conductors that are electrically coupled to navigation electrodes, mapping electrodes, and / or ablation electrodes positioned along the transition portion and / or the proximal portion. In this way, the guidewires of the present disclosure are less likely to prolapse and are thus less likely to short circuit.

[0008] In some examples, at least a portion of the guidewire may be lubricated and / or have a lubricating coating and / or treatment on at least a portion of the outer surface of the guidewire. For example, the distal portion and the transition portion of the guidewire may have a hydrophobic coating, such as a polymer, silicone, polytetrafluoroethylene (PTFE), etc., to increase lubricity. In some examples, the distal portion and the transition portion of the guidewire may have a hydrophilic coating to reduce friction during deployment and to move more easily through tortuous blood vessels. In some examples, at least a portion of the guidewire may include one or more visibility features, such as radiopaque markers or features visible via fluoroscopy, navigation coils, etc.

[0009] In one example, the present disclosure describes a guidewire that includes: a core member that includes: a proximal portion having a first stiffness; and a distal portion having a second stiffness that is less than the first stiffness; an electrical insulator that encapsulates at least a portion of the proximal portion of the core member and the distal portion of the core member, wherein the electrical insulator comprises a material configured to electrically insulate the core member from PFA energy delivered by a pulsed field ablation (PFA) catheter guided by the guidewire; and an electrode positioned along the distal portion.

[0010] In another example, the present disclosure describes a medical system that includes: a pulsed field ablation (PFA) catheter; and a guidewire that includes: a core member that includes: a proximal portion having a first hardness; and a distal portion having a second hardness that is less than the first hardness; an electrical insulator that encapsulates at least a portion of the proximal portion of the core member and the distal portion of the core member, wherein the electrical insulator includes a material configured to electrically insulate the core member from PFA energy delivered by the pulsed field ablation (PFA) catheter; and an electrode positioned along the distal portion.

[0011] In another example, the present disclosure describes a method of forming a guidewire that includes: encapsulating at least a portion of a proximal portion of a core member and a distal portion of the core member within an electrical insulator, wherein the electrical insulator includes a material configured to electrically insulate the core member from PFA energy delivered by a pulsed field ablation (PFA) catheter, wherein the proximal portion of the core member has a first hardness and the distal portion of the core member has a second hardness that is less than the first hardness; and positioning an electrode along the distal portion.

[0012] 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 this disclosure will be apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a conceptual diagram illustrating an exemplary system for delivering ablation.

[0014] Figure 2 is a conceptual diagram illustrating an exemplary guidewire for guiding an ablation catheter.

[0015] Figure 3 is Figure 2 a cross-sectional view of a portion of an exemplary guidewire.

[0016] Figure 4 is a flow diagram illustrating an exemplary method of forming a guidewire for guiding an ablation catheter.

[0017] Figure 5 is a block diagram illustrating an exemplary controller of an ablation system in accordance with one or more aspects of the present disclosure. DETAILED DESCRIPTION

[0018] When using a standard wire coil type guide wire, a wire-mounted device designed to deliver pulsed field ablation (PFA) using high voltages may encounter problems. Standard guide wires may have very little electrical insulation, and if they should become prolapsed, for example, fold back on themselves and / or on the PFA catheter and be adjacent to the PFA energy delivery electrodes, the result may be a short circuit of the high energy delivered between adjacent PFA electrodes. In addition, such standard guide wires do not have individual electrodes mounted thereon that would allow for diagnostic mapping of intracardiac electrograms or delivery of diagnostic pacing in the heart, or delivery of PFA, for example, at a lower voltage and / or PFA dose than via a guide wire-guided PFA catheter. Standard guide wires may also be difficult to track on a cardiac navigation system and may require the physician to use X-ray fluoroscopy to visualize the position of the guide wire.

[0019] According to the devices and techniques disclosed herein, an exemplary guide wire includes a core member that includes a proximal portion having a first hardness and a distal portion having a second hardness that is less than the first hardness. The proximal portion is configured, for example, to allow a user to manipulate the guide wire, and the distal portion is configured, for example, to be non-invasive and have sufficient flexibility to navigate the guide wire with the patient, for example, through a tortuous vasculature. The guide wire also includes an insulator that encapsulates at least a portion of the proximal portion of the core member and the distal portion of the core member, for example, a dielectric material configured to insulate the core member from a relatively high voltage PFA energy (e.g., at least 1,500 volts), the relatively high voltage PFA energy being delivered by a PFA catheter using the guide wire to navigate to a target tissue.

[0020] In some examples, the guide wire may further include an electrode positioned and / or disposed along the distal portion of the core member. The electrode may be external to the insulator and may be electrically connected to a conductor and / or signal line running along the longitudinal length of the guide wire to connect the electrode to a controller and / or sensor. In some examples, the electrode may be electrically connected to the core member, for example, the core member may be conductive and may be configured to serve as a signal line. The guide wire may also include a sheath that surrounds the insulator and is configured to house the conductor and / or signal line. For example, the sheath may encapsulate the signal line and the insulated core member to electrically insulate the signal line from electrical contact with the PFA electrodes of the PFA catheter. In some examples, the electrode may be radiopaque and may be used to assist in guiding the guide wire during insertion of the guide wire into the target tissue. In some examples, the electrode may be configured to deliver PFA energy, such as a high voltage pulsed electric field. For example, the electrode may be configured to deliver a relatively low "dose" and / or amount of PFA energy relative to the PFA electrodes of the PFA catheter in order to provide additional ablation control, such as to "fine tune" the ablation. In some examples, the electrode may be configured to sense signals, such as intracardiac electrogram (EGM) signals, which may be used to determine the position of the guide wire relative to the target tissue and / or relative to the PFA catheter (e.g., the distal end of the PFA catheter).

[0021] Figure 1 is a conceptual diagram showing an exemplary system 100 for delivering ablation. The system 100 includes a catheter 102, a controller 104, and a guidewire 122. Generally speaking, for delivering ablation, a practitioner (e.g., an electrophysiologist, an interventional cardiologist, etc.) may insert the guidewire 122 into a patient and navigate the guidewire to a target tissue site within the patient's body. Then, the practitioner may insert one or more of the catheters 102 into the patient and guide the catheter 102 to the target site via the guidewire. Then, the controller 104 may deliver energy (e.g., PFA energy, radiofrequency ablation energy, laser ablation, radio ablation, cryoablation energy, etc.) to the patient's target tissue via the catheter 102. The ablation may cause damage in the target heart tissue, which may mitigate or stop arrhythmia. In some examples, the controller 104 may cause the catheter 102 to deliver electroporation energy, e.g., PFA energy. Electroporation may be a phenomenon that causes cell membranes to become highly permeable (i.e., permeable to molecules that may be impermeable or semi-permeable to cell membranes). Electroporation may also be referred to as electroosmosis, pulsed electric field treatment, non-thermal irreversible electroporation, irreversible electroporation, high-frequency irreversible electroporation, nanosecond electroporation, or nanoelectroporation, which involves applying high-amplitude pulses to cause physiological modification (i.e., permeabilization) of the cells of the tissue to which the energy is applied. These pulses may be short (e.g., nanosecond, microsecond, or millisecond pulse widths) to allow the application of high voltage, high current (e.g., 20 amperes or more), without the long-duration current flow that may otherwise cause significant tissue heating and muscle stimulation. The pulsed electrical energy may induce the formation of microscopic defects, resulting in hyperpermeabilization of the cell membrane. Depending on the characteristics of the electrical pulses, the electroporated cells may survive after electroporation (referred to as "reversible electroporation") or die (referred to as "irreversible electroporation" (IRE)). Reversible electroporation may be used to transfer reagents (including genetic material and other large or small molecules) into target cells for various purposes, including altering the action potential of cardiomyocytes.

[0022] The catheter 102 may include an elongate structure 112 carrying a plurality of energy delivery elements 110A - 110H (collectively referred to as "energy delivery elements 110"). The energy delivery elements may include electrodes (e.g., in the case of a PFA catheter), cryogenic elements (e.g., in the case of a cryoablation catheter), radiofrequency elements (e.g., in the case of a radiofrequency ablation catheter), or another energy delivery element. Although the techniques of the present disclosure are applicable to any ablation catheter, Figure 1The example relates to a PFA catheter. The catheter 102 can generally include features that enable the catheter 102 to be inserted into a patient and enable the catheter 102 to be navigated to a target tissue site. The elongate structure 112 can include a distal portion 106 and a proximal portion 108. The energy delivery element 110 can generally be positioned at the distal portion 106, while the proximal portion 108 can be connected to the controller 104. The energy delivery element 110 can have any suitable geometry. Example geometries of the electrodes include, but are not limited to, a circular (e.g., annular) electrode around the body of the lead, a conformable electrode, a hoop electrode, a segmented electrode (e.g., electrodes disposed at different circumferential positions around the lead rather than a continuous annular electrode), and any combination thereof (e.g., an annular electrode and a segmented electrode). The energy delivery element 110 can be axially distributed along the longitudinal axis LA of the elongate structure 112 or distributed in a number of other configurations. In some examples, the catheter 102 can include one or more energy delivery elements 110, and the geometry of the one or more energy delivery elements 110 can include a balloon that can be inflated during ablation and deflated when navigating the catheter 102 to the target tissue. The delivery element 110 can also be in a circular form, in an array, along a plurality of splines, or other configurations.

[0023] The elongate structure 112 can include a conductor configured to carry an electrical signal between the energy delivery element 110 and the controller 104. In some examples, the elongate structure 112 can include a separate conductor for each energy delivery element in the energy delivery element 110. For example, in an Figure 1 example where the energy delivery element 110 includes eight electrodes, the elongate structure 112 can include eight separate conductors. In this way, the elongate structure can enable each electrode in the energy delivery element 110 to be driven with a different signal from the controller 104. In other examples, multiple electrodes in the energy delivery element 110 can share a common conductor. For example, the energy delivery elements 110C and 110D can be connected to the same (e.g., common) conductor. Although such a common conductor arrangement may reduce the flexibility of the energy delivery element (e.g., since the electrodes connected to the common conductor can be driven with the same signal), such an arrangement can reduce manufacturing complexity and / or cost and can increase the structural flexibility of the catheter 102.

[0024] As Figure 1As shown, the energy delivery element 110 may include a distal electrode (e.g., energy delivery element 110A), which may be an annular electrode that is a “cap” covering at least a portion of the end of the elongate structure 112. In some examples, the distal electrode may be beveled or otherwise rounded (e.g., to enable the catheter 102 to more easily pass through the patient's anatomy). The energy delivery element 110 may include an annular electrode adjacent to the distal electrode (e.g., energy delivery element 110B). The annular electrode may be separated from the distal electrode (axially along the LA). The energy delivery element 110 may include one or more pairs of annular electrodes. A pair of annular electrodes may include two adjacent closely spaced electrodes in the energy delivery element 110. For example, in Figure 1 the example, energy delivery elements 110C and 110D may form a first pair of annular electrodes, energy delivery elements 110E and 110F may form a second pair of annular electrodes, and energy delivery elements 110G and 110H may form a third pair of annular electrodes. Generally, the first pair of annular electrodes (i.e., energy delivery elements 110C and 110D) may be accompanied by one or more additional electrodes. The one or more additional electrodes may include any combination of pairs of annular electrodes and coil electrodes (e.g., electrodes including a conductor helically wound around the elongate structure 112).

[0025] In Figure 1 the example, the energy delivery element 110 is illustrated as having a diameter greater than that of the elongate structure 112. In some examples, one or more of the energy delivery elements in the energy delivery element 110 may have a diameter that is approximately equal to or less than the diameter of the elongate structure 112. For example, the energy delivery element 110 may be recessed in the elongate structure 112 such that the combination results in a relatively smooth outer surface.

[0026] The controller 104 may include an energy generator configured to provide electrical pulses to the energy delivery element 110 (or control the delivery of radiofrequency energy or cryogenic energy through the energy delivery element 110) 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 tissues within the cardiac space or pericardial space). For example, the energy generator may be configured and programmed to deliver pulsed high voltage electric fields suitable for achieving desired pulsed, high voltage ablation, such as PFA, “pulsed field ablation” and / or pulsed radiofrequency ablation. In some examples, the energy generator may be configured and programmed for achieving desired cryogenic ablation.

[0027] The guidewire 122 may include an elongate member configured to be inserted into a patient's body to a target tissue site and to guide the catheter 102 to the target tissue site. For example, the catheter 102 may include a lumen configured to receive the guidewire 122 and to permit the catheter 102 to advance along the guidewire 122 within the patient's body to the target tissue site. Since the guidewire 122 may be used in conjunction with the catheter 102, the elongate member of the guidewire 122 may be a core member encapsulated within an electrical insulator configured to electrically insulate the core member from electrical energy (such as PFA energy) delivered by the energy delivery element 110. In some examples, the core member may comprise stainless steel, nitinol (e.g., nitinol), a polymer, an additional polymer hardened structure, or any suitable material configured to be inserted into a patient's body, advance within the patient's body to a target tissue site, and guide the catheter 102. In some examples, the insulator may be configured to electrically isolate the core member from a voltage of, for example, at least 1,500 volts, or at least 2,000 volts, or at least 3,000 volts, or at least 4,000 volts, or at least 6,000 volts, or at least 8,000 volts, and the insulator may be configured to do so without dielectric breakdown of the insulator. For example, the insulator may comprise a dielectric material having a resistivity, a dielectric strength, and a thickness configured to electrically isolate the core member from a voltage of at least 1,500 volts. For example, the insulator may include a polyimide having a coating thickness between about 1 micron and 500 microns, between about 10 microns and 50 microns, or between about 10 microns and about 30 microns.

[0028] The guidewire 122 may include and / or carry one or more electrodes, such as electrodes 124A and 124B (collectively referred to as "electrodes 124"). The electrodes 124 may be conductors configured to sense current and / or fields and / or serve as energy delivery elements (e.g., PFA delivery elements), radio frequency elements, or other energy delivery elements. The electrodes 124 may be configured as energy delivery elements configured to deliver cryogenic energy. In some examples, the electrodes 124 may be substantially similar to the energy delivery element 110, however, smaller in size and / or energy delivery capabilities. The guidewire 122 may include a distal portion 126 and a proximal portion 128. The electrodes 124 may generally be positioned at the distal portion 126, while the proximal portion 128 may be connected to the controller 104.

[0029] In some examples, the guidewire 122 may include one or more proximal electrical connectors (not shown) configured to provide electrical insulation, mechanical support, and to reduce interference of the connectors with the environment, e.g., snagging or hooking on a surgical drape and / or other portions of the environment external to the patient's body. For example, the guidewire 122 may include a proximal cable and / or connector as described below with reference to Figure 2 and Figure 3 and the guidewire 222.

[0030] The electrode 124 can have any suitable geometry. Exemplary geometries of the electrode include, but are not limited to, a circular (e.g., annular) electrode around the core member of the guidewire 122, a conformable electrode, a hoop electrode, a segmented electrode (e.g., electrodes disposed at different circumferential positions around the guidewire 122 rather than a continuous annular electrode), or any combination thereof (e.g., an annular electrode and a segmented electrode). The electrode 124 can be axially distributed along the longitudinal axis LA of the guidewire 122. The electrode 124 can also be in a circular form, in an array, along multiple splines, or other configurations.

[0031] The guidewire 122 can include signal lines, such as conductors, configured to carry electrical signals between the electrode 124 and the controller 104. In some examples, the guidewire 122 can include separate signal lines for each electrode in the electrode 124. For example, in an example where the electrode 124 includes two electrodes Figure 1 the guidewire 122 can include two separate conductors. In this way, the guidewire 122 can enable each electrode of the electrode 124 to be driven by different signals from the controller 104 and / or enable the controller 104 to acquire different signals sensed by different electrodes 124. In other examples, multiple electrodes in the electrode 124 can share a common conductor. For example, electrodes 124A and 124B can be connected to the same (e.g., common) conductor. Although such a common conductor arrangement may reduce the flexibility of the energy delivery element (e.g., since electrodes connected to the common conductor can be driven by the same signal), such an arrangement can reduce manufacturing complexity and / or cost and can increase the structural flexibility of the guidewire 122.

[0032] As Figure 1 shown, the electrode 124 can include a terminal electrode (e.g., electrode 124A), which can be an annular electrode having a "cap" covering at least a portion of the end of the guidewire 122. In some examples, the terminal electrode can be beveled or otherwise rounded (e.g., to enable the guidewire 122 to more easily pass through the patient's anatomy). The electrode 124 can include an annular electrode (e.g., electrode 124B) adjacent to the terminal electrode. The annular electrode can be separated from the terminal electrode (axially along the LA). The electrode 124 can include one or more pairs of annular electrodes (not shown). A pair of annular electrodes can include two adjacent closely spaced electrodes in the electrode 124. Generally, one or more pairs of annular electrodes of the guidewire 122 can be accompanied by one or more additional electrodes. The one or more additional electrodes can include any combination of pairs of annular electrodes and coil electrodes (e.g., electrodes including conductors helically wound around the guidewire 122).

[0033] In Figure 1In the example, the energy electrode 124 is illustrated as having a larger diameter than the guidewire 122. In some examples, one or more of the electrodes 124 may have a diameter that is substantially equal to the diameter of the guidewire 122. For example, the electrode 124 may be recessed in the guidewire 122 such that the combination results in a relatively smooth outer surface.

[0034] The controller 104 may include an energy generator configured to deliver electrical pulses to the electrode 124 (or to control the delivery of radiofrequency energy or cryogenic energy via the electrode 124 configured as a radiofrequency delivery element or a cryogenic energy delivery element) 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 pulses, high voltage electric fields suitable for achieving desired pulsed, high voltage ablation, such as PFA, "pulsed electric field ablation" and / or pulsed radiofrequency ablation, although the voltage may be less than the voltage of the energy delivery element 110. In some examples, the energy generator may be configured and programmed for achieving desired cryogenic ablation. In some examples, the controller 104 may include circuitry configured to receive and / or acquire electrical signals (e.g., EGM signals, etc.) sensed and / or received by the electrode 124.

[0035] In some examples, the guidewire 122 may have a stiffness and / or flexibility that varies along its longitudinal length. For example, the distal portion 126 may be more flexible to navigate through the patient's body non-invasively. For example, the distal portion 126 may be a "soft tip" with significant flexibility. The proximal portion 128 may be stiffer to improve the steerability of the guidewire, e.g., by a clinician. In some examples, the guidewire 122 may include a transition portion (shown in Figure 2 between the proximal portion 128 and the distal portion 126) having a stiffness and / or flexibility between the proximal portion 128 and the distal portion 126. The transition region may be configured to provide a smooth stiffness transition between the stiffness and / or flexibility of the proximal portion 128 and the distal portion 126, e.g., to reduce and / or eliminate kinking of the guidewire 122.

[0036] The techniques of the present disclosure can provide improved energy delivery, such as PFA energy, using a high-voltage PFA catheter. For example, the guidewire 122 can be configured to reduce and / or prevent short circuits of high voltage between adjacent PFA electrodes while maintaining a flexible, atraumatic, navigable distal portion and / or tip. The techniques of the present disclosure can also improve the delivery of PFA energy by providing additional energy delivery elements (e.g., electrodes 124) on the guidewire 122, which can enable independent delivery of energy relative to the PFA catheter 102 in different amounts and / or amplitudes. Additionally, the techniques of the present disclosure can also improve the navigation of the guidewire 122 by providing electrodes 124, which can be configured as radiopaque and / or current and / or electric field sensors that can be used to determine the positioning of the distal portion 126 based on imaging and / or the electrical response of the patient's anatomy.

[0037] Figure 2 is a conceptual diagram showing an exemplary guidewire 222 for guiding an ablation catheter (e.g., PFA catheter 102). The guidewire 222 includes an elongate member 212, electrodes 224A - 224J (collectively referred to as "electrodes 224"), and an optional navigation coil 232. The guidewire 222 can be substantially similar to the guidewire 122 described above. For example, the elongate member 212 can be configured to be inserted into a patient's body to a target tissue site and guide the catheter 102 to the target tissue site, and can include a core member encapsulated in an electrical insulator configured to electrically insulate the core member from electrical energy (such as PFA energy) delivered by the energy delivery element 110.

[0038] In the example shown, the guidewire 122 includes a distal portion 226, a proximal portion 228, and a transition portion 230, each of which can be substantially similar to the proximal portion 126, distal portion 128, and transition portion described above, respectively. The electrodes 224 can be substantially similar to the electrodes 124 described above. In the example shown, the guidewire 222 shows an exemplary distribution of the electrodes 124 along the distal portion 226 and the transition portion 230. Additionally, the distal portion 226 can be a soft tip and / or a "J-tip" distal portion.

[0039] In the example shown, the distal portion 226 includes a tip electrode 224A, an electrode 224B (which can be an electrode pair 224A–224B), and electrodes 224C–224F. The transition portion 230 includes electrodes 224G–224J, and the proximal portion 228 does not include electrodes. In other examples, the distal portion 226, the transition portion 230, and the proximal portion 228 can include different proportions of the electrodes 224. The distal portion 226 optionally includes a navigation coil 232.

[0040] In some examples, the distal portion 226 is substantially flexible and / or a "soft tip", and the transition portion 230 tapers in hardness from the hardness of the distal portion 226 to the greater hardness of the proximal portion 228 (e.g., such that the transition portion tapers in hardness from a first hardness to a second hardness). In some examples, the thickness and / or material between the distal portion 226, the proximal portion 228, and the transition portion 230 may be different. For example, the thickness of the core member, insulation, and / or signal lines of the distal portion 226 may be less than the thickness of the proximal portion 228, and the thickness may increase from the distal portion 226 to the proximal portion 228 within the transition portion 230. Additionally or alternatively, the proximal portion 228 may include a stiffening structure while the distal portion 226 does not, and the transition portion 230 includes a stiffening structure that tapers between the distal portion 226 and the proximal portion 228. In some examples, the distal portion 226 may include a stiffening structure that is thinner and / or less stiff than the stiffening structure of the proximal portion 228, and the transition portion 230 may include a stiffening structure that tapers in stiffness between the stiffening structures of the distal portion 226 and the proximal portion 228. In some examples, the transition portion 230 may extend from the distal tip of the guidewire 222 for about 5 centimeters (cm) to 7 cm, or about 8 cm.

[0041] In some examples, the available length of the guidewire 222 is about 170 cm to 210 cm, and the outer diameter of the guidewire 222 is about 0.7 mm to 1.0 mm (including the electrodes), and the radius of the "tip" is about 2 mm to 4 mm. In some examples, the electrodes 224 may be platinum iridium and have a length of about 0.5 mm to 4.0 mm. In some examples, the tip electrodes 224A and / or 224B may be metal balls at the distal tip of the guidewire 222. In some examples, the electrodes 224C–224J may have an edge-to-edge spacing of about 5.0 mm or about 3.0 mm to about 10.0 mm.

[0042] Figure 3 is Figure 2 A cross-sectional view of a portion of an exemplary guidewire 222. In the example shown, the guidewire 222 includes a core member 240, an electrical insulator 242, electrodes 224, signal lines 246, 248, and an electrical insulation sheath 244.

[0043] The core member 240 may include a proximal portion 240P, a distal portion 240D, and a transition portion 240T (e.g., collectively referred to as "core member 240"). The proximal portion 240P of the core member may have a first hardness, the distal portion 240D of the core member may have a second hardness that is less than the first hardness, and the transition portion 240T of the core member may have a hardness that gradually decreases from the first hardness to the second hardness along its longitudinal (e.g., axial) length. In this way, the guidewire 222 may have a correspondingly varying hardness. For example, the proximal portion 228 may have a first guidewire 222 hardness, the distal portion 226 may have a second guidewire 222 hardness, and the transition portion 230 may have a guidewire 222 hardness that gradually decreases from the first guidewire 222 hardness to the second guidewire 222 hardness. In other words, the hardness of the guidewire 222 may correspond to the hardness of the core member 240, where other components and / or structures (e.g., the electrical insulator 242, signal lines 246, 248, electrical insulation sheath 244, any polymer hardening structures, and electrode 224) contribute to the overall hardness of the guidewire 222, although to a lesser extent in some examples.

[0044] In the illustrated example, the first hardness, second hardness, and transition hardness of the core member 240 correspond to the thicknesses of the proximal portion 240P, distal portion 240D, and transition portion 240T, respectively. For example, the proximal portion 240P of the core member has a greater thickness and / or diameter than the distal portion 240D of the core member, and the transition portion 240T varies in thickness between the two. In other examples, each of the proximal portion 240P, distal portion 240D, and transition portion 240T may have the same thickness, and the hardness of the materials used may be such that the proximal portion 240P of the core member has a greater hardness than the distal portion 240D of the core member, where the transition portion 240T varies in hardness between the hardness of the proximal portion 240P of the core member and the distal portion 240D of the core member. In some examples, each of the proximal portion 240P, distal portion 240D, and transition portion 240T may have the same thickness, and the hardness and / or material of any one of the core member 240, electrical insulator 242, electrode 224, signal lines 246, 248, and / or electrical insulation sheath 244 may, individually or in any combination, cause the guidewire 222 to have a greater hardness at the proximal portion than at the transition portion and a greater hardness at the transition portion than at the distal portion of the guidewire 222. In some examples, the hardness of the guidewire 222 may vary along its length by changing the hardness of any one of the core member 240, electrical insulator 242, and / or electrical insulation sheath 244.

[0045] The core member 240 may comprise stainless steel, nitinol, a polymeric structure, and / or any material suitable as a guide wire core. In some examples, the core member 240 comprises a polymer-hardened structure. For example, the core member 240 may comprise at least one of polyetheretherketone (PEEK), polyimide, and / or polyamic acid (such as PyRE-M.L.). In some examples, the different hardnesses of the proximal portion 240P, the distal portion 240D, and the transition portion 240T are due to different amounts, types, and / or thicknesses of the polymer-hardened structure. In some examples, the electrically insulating sheath 244 may comprise a polymer-hardened structure and may encapsulate at least a portion of the signal wires (e.g., signal wires 246, 248). In other examples, the polymer-hardened structure may be separate from the electrically insulating sheath 244 and may encapsulate at least a portion of the signal wires. In some examples, the polymer-hardened structure, the core member 240, the electrical insulator 242, and / or the insulating sheath 244 may be configured to provide improved and / or specific handling characteristics, such as at least a threshold thickness, friction, and / or grip and / or maneuverability.

[0046] The electrical insulator 242 may include a proximal portion 242P, a distal portion 242D, and a transition portion 242T (e.g., collectively referred to as "the electrical insulator 242"). In some examples, the thickness of the electrical insulator 242 may vary, e.g., corresponding to the varying hardness of the core member 240. For example, the proximal portion 242P of the electrical insulator may be thicker than the distal portion 242D of the electrical insulator, and the thickness of the transition portion 242T of the electrical insulator may vary between the thicknesses of the proximal portion 242P and the distal portion 242D. In this manner, the electrical insulator 242 may contribute to the varying hardness of the guide wire 222, e.g., between the distal portion 226, the proximal portion 228, and the transition portion 230. In other examples, the proximal portion 242P, the distal portion 242D, and the transition portion 242T may have substantially the same thickness, and in still other examples, the thicknesses of the proximal portion 242P, the distal portion 242D, and the transition portion 242T may vary conversely, e.g., the proximal portion 242P of the electrical insulator may be thinner than the distal portion 242D of the electrical insulator, and the thickness of the transition portion 242T of the electrical insulator may vary between the thicknesses of the proximal portion 242P and the distal portion 242D. In other words, the core member 240 may be the primary driver of the hardness of the guide wire 222, and the thickness of the electrical insulator 242 may vary independently of the desired hardness of the distal portion 226, the proximal portion 228, and the transition portion 230.

[0047] The electrical insulator 242 can be any material suitable for insertion into a patient and electrically isolating the core member 240 from the PFA energy delivered by the ablation catheter 102, which PFA energy has a voltage of, for example, at least 1,500 volts, or at least 2,000 volts, or at least 3,000 volts, or at least 4,000 volts, or at least 6,000 volts, or at least 8,000 volts, and the electrical insulator 242 can be configured to do so without dielectric breakdown of the electrical insulator 242. In some examples, the electrical insulator 242 can be configured to electrically isolate the core member 240 from the PFA energy delivered by the ablation catheter 102 in combination with the electrical insulation sheath 244, which PFA energy has a voltage of at least 1,500 volts (or at least 2,000 volts, or at least 3,000 volts, or at least 4,000 volts, or at least 6,000 volts, or at least 8,000 volts). For example, each of the electrical insulator 242 and the electrical insulation sheath 244 may not be configured to electrically isolate the core member 240 from at least 1,500 volts, but rather may be configured to electrically isolate the core member 240 from at least 1,500 volts in combination, for example, when the electrical insulation sheath 244 surrounds the electrical insulator 242. In some examples, the electrical insulator 242 can include parylene, polyimide, and / or polyamic acid (such as PYRE-M.L.) or any suitable electrical insulating material. In some examples, the insulator 242 can have a thickness 243 between about 1 micron and 500 microns, between about 10 microns and 50 microns, or between about 10 microns and about 30 microns. In some examples, the sheath 244 can have a thickness 245 between about 1 micron and 500 microns, between about 10 microns and 50 microns, or between about 10 microns and about 30 microns.

[0048] The signal lines 246, 248 can be configured to be electrically connected to the electrodes of the electrode 224. In the example shown, the signal line 246 is electrically connected to the electrode 224F, and the signal line 248 is electrically connected to the electrode 224I. The guidewire 222 can include fewer or more signal lines. For example, it can include signal lines configured to be electrically connected to the electrodes 224G, 224H, and 224I and at different circumferential positions around the guidewire 222 (and thus not visible in the Figure 3 cross-section), or all of the electrodes in the electrode 224 can be configured to be electrically connected to a single signal line. In some examples, the core 240 can be configured to be electrically connected to one or more of the electrodes of the electrode 224 and serve as a signal line. Generally, the signal lines 246, 248 include a conductive material. In some examples, the core member 240 can include a conductive material and can be configured to be electrically connected to the electrodes of the electrode 224.

[0049] The signal lines 246, 248, and / or the core 240 may be configured to connect to a signal and / or power source at the proximal portion 228. For example, the proximal portion 228 of the guidewire 222 may be configured to connect to the controller 104. For example, the signal lines 246, 248, and / or the core 240 may be connected to the controller 104 via a single and / or multiple conductor connection cable and / or connector (not shown). For example, the system 100 may include a guidewire 222 and a proximal connection cable and / or connector configured to slide over a portion of the proximal portion 228 of the guidewire 222 and electrically connect and / or engage with the signal lines 246, 248, and / or the core 240 to connect one or more of the electrodes 224 and / or the navigation coil 232 to a signal or power source, such as the controller 104. In some examples, the proximal connector may be configured to provide electrical insulation and / or isolation and mechanical insulation, isolation, and / or support for the proximal termination point or end of the signal lines 246, 248, and / or the core 240, e.g., to insulate and cover the proximal ends of the signal lines 246, 248, and / or the core 240. In some examples, the proximal connector may be a permanently connected cable or connector, or the proximal connector may be a detachable cable or connector. In some examples, the electrodes 224 and / or the navigation coil 232 may be configured to wirelessly connect to a power and / or signal source, e.g., via a wireless power and / or signal interface.

[0050] The electrical insulation sheath 244 may include a proximal portion 244P, a distal portion 244D, and a transition portion 244T (e.g., collectively referred to as the “electrical insulation sheath 244”). In some examples, the thickness of the electrical insulation sheath 244 may vary, e.g., corresponding to the varying stiffness of the core member 240. For example, the proximal portion 244P of the electrical insulation sheath may be thicker than the distal portion 244D of the electrical insulation sheath, and the thickness of the transition portion 244T of the electrical insulation sheath may vary between the thicknesses of the proximal portion 244P and the distal portion 244D. In this manner, the electrical insulation sheath 244 may contribute to the varying stiffness of the guidewire 222, e.g., between the distal portion 226, the proximal portion 228, and the transition portion 230. In other examples, the proximal portion 244P, the distal portion 244D, and the transition portion 244T may have substantially the same thickness, and in still other examples, the thicknesses of the proximal portion 244P, the distal portion 244D, and the transition portion 244T may vary conversely, e.g., the proximal portion 244P of the electrical insulator may be thinner than the distal portion 244D of the electrical insulator, and the thickness of the transition portion 244T of the electrical insulator may vary between the thicknesses of the proximal portion 244P and the distal portion 244D. In other words, the core member 240 may be the primary driver of the stiffness of the guidewire 222, and the thickness of the electrical insulation sheath 244 may vary independently of the desired stiffness of the distal portion 226, the proximal portion 228, and the transition portion 230. The electrical insulation sheath 244 may surround the electrical insulator 242 and may be configured to accommodate the signal lines 246, 248.

[0051] The electrical insulation sheath 244 may be any material suitable for insertion into a patient and electrically isolating the signal lines 246, 248 from the PFA energy delivered by the ablation catheter 102, which PFA energy has a voltage of, e.g., at least 1,500 volts, or at least 2,000 volts, or at least 3,000 volts, or at least 4,000 volts, or at least 6,000 volts, or at least 8,000 volts, and the insulation sheath 244 may be configured to do so without dielectric breakdown of the electrical insulation sheath 244. In some examples, the electrical insulator 244 may comprise at least one of fluorocarbon polymers, polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), parylene, polyimide, and / or polyamic acid (such as PyRE-M.L.) or any suitable electrical insulating material.

[0052] The electrodes 224 are positioned along the distal portion 226 and the transition portion 230, as Figure 2 and Figure 3As shown. In some examples, one or more of the electrodes 224 are configured to sense an intracardiac electrocardiogram (ECG) signal, deliver high voltage pulsed electric fields, and / or be radiopaque. In some examples, one or more of the electrodes 224 may include a modified surface. For example, one or more of the electrodes 224 may include a high surface area conductive surface such as titanium nitride or tantalum nitride.

[0053] Generally, each of the electrodes 224 (e.g., Figure 2 and Figure 3 the electrodes 224A, 224J shown in) are configured not to short circuit the energy delivery element 110. For example, the longitudinal length of the electrode 224 may be less than the distance between a first PFA electrode (e.g., the energy delivery element 110B) disposed on the outer surface of the PFA catheter and a second, adjacent PFA electrode (e.g., the energy delivery element 110C) disposed on the outer surface of the PFA catheter, which second PFA electrode may have a different potential. For example, short circuiting electrode pairs such as 110A, 110B or 110C, 110D etc. may not be a problem because the elements / electrodes may have the same potential and / or be at the same voltage. In other words, the PFA electrode pairs may already be electrically connected and effectively short circuited, however, short circuiting or electrically connecting adjacent energy delivery elements 110 may be undesirable. The electrode 224 may be configured not to short circuit adjacent energy delivery elements 110 having different voltages and / or potentials, for example by having a longitudinal length less than the distance between such adjacent energy delivery elements 110. In this way, if a portion of the distal portion 226 of the guide wire 222 folds back on itself and / or on the PFA catheter 102, the guide wire 222 is configured to prevent short circuiting of the PFA electrodes.

[0054] Figure 4 is a flow chart showing an exemplary method of forming a guide wire 222 for guiding an ablation catheter 102. With respect to Figure 2 and Figure 3 the guide wire 222 of is described, however, Figure 4 however, Figure 4 the techniques of can be used to manufacture different guide wires.

[0055] The manufacturer may encapsulate at least a portion of the proximal portion 240P of the core member 240 and the distal portion 240D of the core member 240 within an electrical insulator 242 that includes a material (402) configured to electrically insulate the core member from PFA energy delivered by a pulsed field ablation (PFA) catheter. The manufacturer may then position the electrode 224 (404) along the distal portion 226. In some examples, the manufacturer may position one or more electrodes along the distal portion 226 and the transition portion 230 of the guidewire 222 and then electrically connect the electrode 224 to the controller 104 via one or more signal lines (e.g., signal lines 246, 248). The manufacturer may then encapsulate the signal line or signal lines 246, 248 within a sheath, such as an electrical insulation sheath 244 (406) around the electrical insulator 242. In some examples, the manufacturer may encapsulate the core member 240, the electrical insulator 242, and the signal lines 246, 248 within the electrical insulation sheath 244, where the signal lines 246, 248 are between the electrical insulator 242 and the electrical insulation sheath 244.

[0056] Figure 5 is a block diagram illustrating an example controller of a multi-mode PFA system in accordance with one or more aspects of the present disclosure. Figure 5 The controller 504 of Figure 1 may be an example of the controller 104 of Figure 5 As shown, the controller 504 may include an energy generator 516, a processing circuit 518, a user interface 520, a storage device 522, and a sensing circuit 524.

[0057] The energy generator 516 may be configured to provide electrical pulses to an energy delivery element and / or an electrode (e.g., Figure 1 the energy delivery element 110 of Figure 2 and / or Figure 3 the electrode 224 of Figure 5 to perform an electroporation procedure on cardiac tissue or other tissue within a patient's body, such as kidney tissue, airway tissue, and organs or tissues within the cardiac space or pericardial space. For example, the energy generator 516 may be configured and programmed to deliver pulsed high-voltage electric fields suitable for achieving a desired pulse, high-voltage ablation (referred to as "pulsed field ablation" or "pulsed electric field ablation"), and / or pulsed radiofrequency ablation. Although shown as a single energy generator in the

[0058] The processing circuitry 518 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), discrete logic circuitry, or any other processing circuitry configured to provide the functionality attributable to the processing circuitry 518 that may be embodied as firmware, hardware, software, or any combination thereof herein. The processing circuitry 518 controls the energy generator 516 to generate signals according to various settings (e.g., the linear setting 530 or the focusing setting 532). In some examples, the processing circuitry 518 may execute other instructions stored in the storage device 522 to perform PFA.

[0059] The sensing circuitry 524 may be configured to receive signals from the energy delivery element 110 and / or 224. For example, the electrode 224 may be configured to sense EGM signals, and the sensing circuitry 524 may be configured to receive ECG signals from one or more electrodes 224.

[0060] The storage device 522 may be configured to store information within the controller 504 during operation. The storage device 522 may include a computer-readable storage medium or a computer-readable storage device. In some examples, the storage device 522 includes one or more of short-term memory or long-term memory. The storage device 522 may include, for example, random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), magnetic disks, optical disks, flash memory, or various forms of electrically programmable read-only memory (EPROM) or electrically erasable programmable read-only memory (EEPROM). In some examples, the storage device 522 is used to store data indicative of instructions, respectively, executed by the processing circuitry 518, for example.

[0061] The user interface 520 may include buttons or a keypad, lights, a speaker for voice commands, a display (such as a liquid crystal (LCD), light emitting diode (LED), or organic light emitting diode (OLED)). In some examples, the display includes a touch screen. The user interface 520 may be configured to display any information related to the execution of PFA. The user interface 520 may also receive user input (e.g., selection of a linear PFA mode or a focusing PFA mode) via the user interface 520. The user input may be in the form of, for example, pressing a button on the keypad or selecting an icon from the touch screen.

[0062] Accordingly, although exemplary systems and techniques have been shown and described, it should be understood that all terms used herein are descriptive and not restrictive, and many changes, modifications, and substitutions may be made by those skilled in the art without departing from the spirit and scope of the present invention. The following examples are examples of the systems, devices, and methods described herein.

[0063] Example 1. A guidewire, the guidewire comprising: a core member, the core member comprising: a proximal portion having a first hardness; and a distal portion having a second hardness less than the first hardness; an electrical insulator encapsulating at least a portion of the proximal portion of the core member and the distal portion of the core member, wherein the electrical insulator comprises a material configured to electrically insulate the core member from pulsed field ablation (PFA) energy delivered by a PFA catheter guided by the guidewire; and an electrode positioned along the distal portion.

[0064] Example 2. The guidewire according to claim 1, wherein the core member further comprises: a transition portion between the proximal portion and the distal portion, wherein the transition portion gradually decreases in hardness from the first hardness to the second hardness.

[0065] Example 3. The guidewire according to claim 2, wherein the guidewire further comprises a second electrode positioned along the transition portion.

[0066] Example 4. The guidewire according to claim 1 or claim 2, the guidewire further comprising: a sheath surrounding the electrical insulator and configured to accommodate a signal wire, wherein the signal wire is configured to be electrically connected to the electrode.

[0067] Example 5. The guidewire according to claim 4, wherein the electrical insulator is composed of parylene, and wherein the sheath is composed of at least one of polytetrafluoroethylene (PTFE) or ethylene tetrafluoroethylene (ETFE).

[0068] Example 6. The guidewire according to any one of claims 1 to 5, wherein the electrical insulator is configured to electrically isolate the core member from PFA energy having a voltage of at least 1,500 volts delivered by the PFA catheter.

[0069] Example 7. The guidewire according to any one of claims 1 to 6, the guidewire further comprising a navigation coil positioned along the distal portion.

[0070] Example 8. The guidewire according to any one of claims 1 to 7, wherein the electrode is configured to sense an intracardiac electrocardiogram (ECG) signal.

[0071] Example 9. The guidewire according to any one of claims 1 to 8, wherein the electrode is radiopaque.

[0072] Example 10. The guidewire according to any one of claims 1 to 9, wherein the electrode is configured to deliver a high-voltage pulsed electric field, and wherein the surface of the electrode comprises a high-surface-area conductive surface comprising at least one of titanium nitride or tantalum nitride.

[0073] Example 11. The guidewire according to any one of claims 1 to 10, wherein the core member comprises a polymer hardened structure.

[0074] Example 12. The guidewire according to claim 11, wherein the polymer hardened structure comprises at least one of polyetheretherketone (PEEK) or polyimide.

[0075] Example 13. The guidewire according to claim 12, wherein the polymer hardened structure encapsulates at least a portion of a signal wire configured to be electrically connected to the electrode.

[0076] Example 14. The guidewire according to any one of claims 1 to 13, wherein the length of the electrode along the longitudinal axis of the guidewire is less than the distance between a first PFA electrode disposed on the outer surface of the PFA catheter and a second PFA electrode disposed on the outer surface of the PFA catheter, wherein the second PFA electrode is adjacent to the first PFA electrode, wherein the first PFA electrode has a first potential, and the second PFA electrode has a second potential different from the first potential.

[0077] Example 15. A medical system comprising: a pulsed field ablation (PFA) catheter; and a guidewire comprising: a core member comprising: a proximal portion having a first hardness; and a distal portion having a second hardness less than the first hardness; an electrical insulator encapsulating at least a portion of the proximal portion of the core member and the distal portion of the core member, wherein the electrical insulator comprises a material configured to electrically insulate the core member from PFA energy delivered by the pulsed field ablation (PFA) catheter; and an electrode positioned along the distal portion.

[0078] Example 16. The medical system according to claim 15, wherein the core member further comprises: a transition portion between the proximal portion and the distal portion, wherein the transition portion gradually decreases in hardness from the first hardness to the second hardness.

[0079] Example 17. The medical system according to claim 16, wherein the guidewire further comprises a second electrode positioned along the transition portion.

[0080] Example 18. The medical system according to any one of claims 15 to 17, the medical system further comprising: a sheath that surrounds the electrical insulator and is configured to receive a signal line, wherein the signal line is configured to be electrically connected to the electrode.

[0081] Example 19. The medical system according to claim 18, wherein the electrical insulator is composed of parylene, and wherein the sheath is composed of at least one of polytetrafluoroethylene (PTFE) or ethylene tetrafluoroethylene (ETFE).

[0082] Example 20. The medical system according to any one of claims 15 to 19, wherein the electrical insulator is configured to electrically isolate the core member from PFA energy having a voltage of at least 1,500 volts delivered by the ablation catheter.

[0083] Example 21. The medical system according to any one of claims 15 to 20, the medical system further comprising a navigation coil positioned along the distal portion.

[0084] Example 22. The medical system according to any one of claims 15 to 21, wherein the electrode is configured to sense an intracardiac electrocardiogram (ECG) signal.

[0085] Example 23. The medical system according to any one of claims 15 to 22, wherein the electrode is radiopaque.

[0086] Example 24. The medical system according to any one of claims 15 to 23, wherein the electrode is configured to deliver a high voltage pulsed electric field.

[0087] Example 25. The medical system according to any one of claims 15 to 24, wherein the core member includes a polymer hardened structure.

[0088] Example 26. The medical system according to claim 25, wherein the polymer hardened structure comprises polyetheretherketone (PEEK).

[0089] Example 27. The medical system according to claim 25 or claim 26, wherein the polymer hardened structure encapsulates at least a portion of a signal line, wherein the signal line is configured to be electrically connected to the electrode.

[0090] Example 28. The medical system according to any one of claims 15 to 27, wherein the length of the electrode along the longitudinal axis of the guide wire is less than the distance between a first PFA electrode disposed on the outer surface of the PFA catheter and a second PFA electrode disposed on the outer surface of the PFA catheter, wherein the second PFA electrode is adjacent to the first PFA electrode, wherein the first PFA electrode has a first potential, and the second PFA electrode has a second potential different from the first potential.

[0091] Example 29. The medical system according to any one of claims 15 to 28, wherein the core member comprises a conductive material and is configured to be electrically connected to the electrode.

[0092] Example 30. A method of forming a guide wire, the method comprising: encapsulating at least a portion of the proximal portion of the core member and the distal portion of the core member in an electrical insulator, wherein the electrical insulator comprises a material configured to electrically insulate the core member from PFA energy delivered by a pulsed field ablation (PFA) catheter, wherein the proximal portion of the core member has a first hardness and the distal portion of the core member has a second hardness less than the first hardness; and positioning an electrode along the distal portion.

[0093] Example 31. The method according to claim 30, the method further comprising: encapsulating a signal wire in a sheath that surrounds the electrical insulator, wherein the signal wire is between the electrical insulator and the sheath, and wherein the signal wire is electrically connected to the electrode.

[0094] The techniques described in this disclosure may be implemented, at least in part, in hardware, software, firmware, or any combination thereof. For example, 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 circuitry; as well as any combination of such components. The term "processor" or "processing circuit" generally may refer to any of the foregoing logic circuitry alone or in combination with other logic circuitry or any other equivalent circuitry. A control unit including hardware may also form one or more processors or processing circuits configured to perform one or more techniques of this disclosure.

[0095] Such hardware, software, and firmware can be implemented and can perform various operations, either within the same device, in separate devices, and / or among or across multiple devices, on a coordinated basis to support the various operations and functions described in this disclosure. Additionally, any of the described units, circuits, or components can be implemented together or independently 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 separate hardware or software components. Instead, the functions associated with one or more circuits or units can be performed by separate hardware or software components or integrated within common or separate hardware or software components. The processing circuitry described in this disclosure, including one or more processors, can be implemented as fixed-function circuitry, programmable circuitry, or a combination thereof in various examples. Fixed-function circuitry refers to circuitry that provides specific functionality using preset operations. Programmable circuitry refers to circuitry that can be programmed to perform various tasks and provide flexible functionality in executable operations. For example, programmable circuitry can execute software or firmware that causes the programmable circuitry to operate in the manner defined by the instructions of the software or firmware. Fixed-function circuitry can execute software instructions (e.g., to receive stimulation parameters or output stimulation parameters), but the types of operations performed by the fixed-function circuitry are typically immutable. In some examples, one or more of these units can be different circuit blocks (fixed-function or programmable), and in some examples, one or more of these units can be integrated circuits.

[0096] The techniques described in this disclosure can also be embodied or encoded in a computer-readable medium, such as a computer-readable storage medium, containing instructions, which can be described as a non-transitory medium. The instructions embedded or encoded in the computer-readable storage medium can cause a programmable processor or other processor to perform the method, for example, when the instructions are executed. The computer-readable storage medium can include random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, a hard disk, a CD-ROM, a floppy disk, a cassette tape, magnetic media, optical media, or other computer-readable media.

Claims

1. A guide wire, the guide wire comprising: A core member, the core member comprising: A proximal portion having a first hardness; and A distal portion having a second hardness less than the first hardness; An electrical insulator that encapsulates at least a portion of the proximal portion of the core member and the distal portion of the core member, wherein the electrical insulator comprises a material configured to electrically insulate the core member from PFA energy delivered by a pulsed field ablation (PFA) catheter guided by the guidewire; and An electrode positioned along the distal portion.

2. The guide wire according to claim 1, wherein the core member further comprises: A transition portion between the proximal portion and the distal portion, wherein the transition portion gradually decreases in hardness from the first hardness to the second hardness.

3. The guide wire according to claim 2, wherein the guide wire further comprises a second electrode positioned along the transition portion.

4. The guide wire according to claim 1 or claim 2, the guide wire further comprising: An electrical insulation sheath that surrounds the electrical insulator and is configured to accommodate a signal wire, wherein the signal wire is configured to be electrically connected to the electrode.

5. The guide wire according to claim 4, wherein the electrical insulator is composed of parylene, and wherein the electrical insulation sheath is composed of at least one of polytetrafluoroethylene (PTFE) or ethylene tetrafluoroethylene (ETFE).

6. The guide wire according to any one of claims 1 to 5, wherein the electrical insulator is configured to electrically isolate the core member from PFA energy having a voltage of at least 1,500 volts delivered by the PFA catheter.

7. The guide wire according to any one of claims 1 to 6, the guide wire further comprising a navigation coil positioned along the distal portion.

8. The guide wire according to any one of claims 1 to 7, wherein the electrode is configured to sense an intracardiac electrocardiogram (ECG) signal.

9. The guide wire according to any one of claims 1 to 8, wherein the electrode is radiopaque.

10. The guide wire according to any one of claims 1 to 9, wherein the electrode is configured to deliver a high voltage pulsed electric field, and wherein the surface of the electrode comprises a high surface area conductive surface comprising at least one of titanium nitride or tantalum nitride.

11. The guide wire according to any one of claims 1 to 10, wherein the core member comprises a polymer hardened structure.

12. The guide wire according to claim 11, wherein the polymer hardened structure comprises at least one of polyether ether ketone (PEEK) or polyimide.

13. The guide wire according to claim 12, wherein the polymer hardened structure encapsulates at least a portion of a signal wire, wherein the signal wire is configured to be electrically connected to the electrode.

14. The guide wire according to any one of claims 1 to 13, wherein the length of the electrode along the longitudinal axis of the guide wire is less than the distance between a first PFA electrode disposed on the outer surface of the PFA catheter and a second PFA electrode disposed on the outer surface of the PFA catheter, wherein the second PFA electrode is adjacent to the first PFA electrode, wherein the first PFA electrode has a first potential, and the second PFA electrode has a second potential different from the first potential.

15. A medical system, the medical system comprising: A pulsed field ablation (PFA) catheter; And A guidewire, the guidewire comprising: A core member, the core member comprising: A proximal portion having a first hardness; and A distal portion having a second hardness less than the first hardness; An electrical insulator that encapsulates at least a portion of the proximal portion of the core member and the distal portion of the core member, wherein the electrical insulator comprises a material configured to electrically insulate the core member from PFA energy delivered by a pulsed field ablation (PFA) catheter; and An electrode positioned along the distal portion.

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