EP4615355A1

EP4615355A1 - Catheter navigation guidewire

Info

Publication number: EP4615355A1
Application number: EP23821812.7A
Authority: EP
Inventors: Lars M. MATTISON; Sarah E. AHLBERG; Anthony P. Scinicariello; Kenneth C. Gardeski; Disha MISHRA; Gary Robert FIEDLER
Original assignee: Medtronic Inc
Current assignee: Medtronic Inc
Priority date: 2022-11-08
Filing date: 2023-11-07
Publication date: 2025-09-17
Also published as: WO2024102755A1; CN120265228A

Abstract

An example guidewire includes an elongate body and an electromagnetic (EM) sensor disposed along a distal portion of the elongate body. The electromagnetic sensor is configured to be indicative of a position and orientation of the distal portion of the elongate body. The example guidewire also includes an electrode disposed, along the distal portion of the elongate body at a predetermined distance and orientation relative to the electromagnetic sensor.

Description

CATHETER NAVIGATION GUIDEWIRE

[00011 Tliis application claims the benefit of U.S. Provisional Patent Application 63/382,842, filed 08 November 2022, and U.S. Provisional Patent Application

63/517, 134, filed 02 August 2023, the entire contents of both of which are incorporated herein by reference.

TECHNICAL FIELD

[0002] The present technology is related to catheter guidewires. In particular, various examples of the present technology are related to assisting procedures using catheter delivery⁷ devices.

BACKGROUND

[0003] Medical procedures, such as tissue ablation, may be used to treat conditions such as cardiac arrhythmias, which includes atrial fibrillation. , Ablation can be performed to treat cardiac arrhythmias, such as by ablating tissue to stop aberrant electrical propagation and/or disrupt aberrant electrical conduction through cardiac tissue. Ablation techniques include pulsed field ablation (PF A), cryoablation, laser ablation, radioablation, and radiofrequency (RF) ablation.

[0004] Cardiac arrhythmias are a group of conditions that cause an irregular heartbeat or conduction pattern. Ablation may be used to create a lesion or set of lesions at the origin of the irregular heartbeat or in regions that aid in the termination of arrhythmias without causing damage to adjacent structures or surrounding tissue, ideally resulting in no need for a maintenance treatment regimen, such as medications or cardioversions.

SUMMARY

[0005] The present technology is directed to devices, systems, and methods for assisting medical procedures using catheter delivery devices. In examples disclosed herein, a navigation guidewire is configured to visualize a catheter that does not have an electromagnetic sensor using an electromagnetic navigations system . The navigation guidew ire includes one or more electrodes and one or more electromagnetic sensors.

[0006] lire ability to visualize catheters that do not have an EM electromagnetic sensor on an electromagnetic navigation system typically requires adding an electromagnetic sensor to the catheter, e.g., retrofitting an electromagnetic sensor to the

SUBSTITUTE SHEET (RULE 26) catheter in one or several places on the catheter itself, to determine location and orientation of the catheter. However, retrofitting a catheter with electromagnetic sensors can be time-consuming and/or limited or prevented by the available space and build of the catheter.

[D097| In accordance with the devices, systems, and techniques herein, a navigation guidewire includes a distal electromagnetic (EM) sensor and is configured to be used with an electromagnetic navigation system to determine position (e.g., location) and orientation of the catheter within a patient, e.g., a catheter without an electromagnetic sensor. s 00(181 In one example, this disclosure describes a guidewire including: an elongate body; an electromagnetic (EM) sensor disposed along a distal portion of tire elongate body, wherein the electromagnetic sensor is configured to be indicative of a position and orientation of the distal portion of the elongate body; and an electrode disposed along the distal portion of the elongate body at a predetermined distance and orientation relative to the electromagnetic sensor.

[OO09| In another example, this disclosure describes a medical system including: a catheter; and a navigation guidewire including: an elongate body; an electromagnetic (EM) sensor disposed along a distal portion of the elongate body, wherein tire electromagnetic sensor is configured to be indicative of a position and orientation of the distal portion of the elongate body; and an electrode disposed along the distal portion of the elongate body at a predetermined distance and orientation relative to the electromagnetic sensor.

[0010[ In another example, this disclosure describes a method of localizing a catheter within a patient, the method including: moving a guidewire through a vessel of a patient to a target treatment site, wherein the guidewire comprises: an elongate body; an electromagnetic (EM) sensor disposed along a distal portion of the elongate body, wherein the electromagnetic sensor is configured to be indicative of a position and orientation of the distal portion of the elongate body; and an electrode disposed along the distal portion of the elongate body at a predetermined distance and orientation relative to the electromagnetic sensor; moving a catheter through the vessel of the patient to the target treatment site; determining, via processing circuitry' and the electromagnetic sensor, a position and an orientation of the distal portion of the elongate body of the guidew ire; and determining, via the processing circuitry and based on the position and tire orientation of the distal portion of the elongate body of the guidewrire, a position and an orientati on of a distal end of the catheter.

SUBSTITUTE SHEET (RULE 26) [00111 The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description belo-w Other features, objects, and advantages of the techniques described in this disclosure will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF TOE DRAWINGS

[0012| FIG. 1 is a conceptual diagram illustrating an example medical system including a navigation guide wire.

[0013| FIGS. 2A-2E are conceptual diagrams illustrating several example navigation guide wires including various arrangements of electrodes and electromagnetic sensors.

[0014 J FIG. 3A is a perspective view of a distal portion of an example navigation guide wire. FIG. 3B is a transparent, perspective view of the distal portion of the example navigation guidewire of FIG. 3A illustrating internal components of the navigation guide wire.

[0016| FIG. 3C is a transparent, perspecti ve view of a cross-section of the distal portion of the example navigation guidewire of FIG. 3 A illustrating internal components of the navigation guide wire.

[0017[ FIG. 4A is a cross-sectional view of a distal portion of an example navigation guide wire.

[O018| FIG. 4B is another cross-sectional view of the distal portion of the example navigation guide wire of FIG. 4A.

[0019[ FIG. 4C is another cross-sectional view of the distal portion of the example navigation guidewire of FIG. 4A.

[ 0020| FIG. 5A is a partially transparent side view' of a distal portion of an example navigation guide wire.

[O021| FIG. 5B is a partially transparent side view of a distal portion of another example navigation guidewire,

[0022 [ FIG. 5C is a cross-sectional view of a distal portion of the example navigation guide wire of FIG. 5B.

[0023| FIG. 6 is a flow diagram illustrating an example method of localizing a catheter within a patient.

-3-

SUBSTITUTE SHEET (RULE 26) [0024] FIGS. 7A-7D are a series of partially transparent side views of an example navigation guidewire at different stages of localizing the navigation guidewire and a catheter according to the method of FIG. 6.

(0025] FIGS. 7E-7H are a series of representations of portions of the catheter localized at the stages corresponding to FIGS, 7A-7E and according to the method of FIG. 6 and corresponding to FIGS. 7A-7D.

[0026] FIG. 8 is a block diagram illustrating an example controller of a navigation system configured for use with a navigation guidewire.

DETAILED DESCRIPTION

[G027f Medical procedures utilizing one or more catheters to provide treatment to a target treatment site within a patient may use navigation techniques to determine the position and orientation of the catheter(s) in to deliver the treatment. Non-fluoroscopic techniques may include electromagnetic navigation utilizing an EM sensor to determine position and orientation of a catheter within a patient, e.g,, relative to patient anatomy. However, many catheters may not have an EM electromagnetic sensor,

[0028| In accordance with the devices, systems, and techniques herein, a navigation guidewire includes a distal electromagnetic (EM) sensor and is configured to be used with an electromagnetic navigation system to determine position (e.g., location) and orientation of the catheter within a patient, e.g., a catheter without an electromagnetic sensor.

For example, a navigation guidewire is advanced with a catheter to a target position within a patient (e.g., a treatment location or site) with a position and orientation of the distal EM sensor of the navigation guidewire that is known and/or fixed relative to the position and orientation of the distal end of the catheter. For example, the proximal end of the navigation guidewire is marked at a particular distance or distances from a distal end, or from the EM sensor, and the mark may be compared to a proximal end or a. proximal marking of the catheter. Additionally or alternatively, the navigation guidewire may utilize a stop (e.g., a torque tool) that may bump up against a luer at a particular distance from the distal end of the navigation guidewire, or from the EM sensor. In other examples, the catheter may include a distal radiopaque marker that may be compared to a distal radiopaque marker of the navigation guidewire (e.g., an electrode disposed on a distal portion of the navigation guidewire).

SUBSTITUTE SHEET (RULE 26) [0038| In other examples, the navigation guidewire and catheter is advanced separately to the target position, and the position and orientation of the EM sensor of the navigation guidewire relative to the position and orientation of the distal end of the catheter may be determined. For example, the position and orientation of the navigation guidewire relative to the position and orientation of the distal end of the catheter is determined using one or more electrodes disposed along a distal portion of the navigation guidewire, and the position and orientation of the distal portion of the navigation guidewire relative to the target treatment site (e.g., anatomy of the patient) is determined via the EM sensor of the navigation guidewire. Adjustments to both the catheter and navigation guidewire positions and orientations may then be made in preparation for a medical procedure that uses the catheter.

[0031 j In some examples, the navigation guidewire includes one or more electrodes configured to determine a position and orientation of the navigation guidew ire relative to a distal end of the catheter. For example, the navigation guidewire may include the EM sensor near the distal end of the navigation gui dewire and an electrode distal to the EM sensor or proximal to the EM sensor. In some examples, the navigation guidewire may include a plurality of electrodes near the distal end of the navigation guidew ire, e.g., an electrode distal to the EM sensor and proximal to the EM sensor. In some examples, an impedance of the electrode (or impedances of electrodes) may change based on positi on and orientation of the electrode relative to the distal end of the catheter.

|O032] For example, the electrode may be configured to create a weak electric field that interacts with material relatively near the electrode and changes the impedance of the electrode. As the navigation guidewire moves within the patient or a lumen of the catheter, the impedance of the electrode may change. The change in impedance of the electrode as the electrode enters or exits the lumen of the catheter at the distal end of the catheter may be indicative of the position and/or orientation of the distal end of the catheter. The electrode may have a known (e.g., fixed) position and orientation on the navigation guidewire relative to the position and orientation of the EM sensor of the navigation guidewire, such that the electrode may be used to determine the position and orientation of the EM sensor relative to the position and orientation of the distal end of the catheter. An EM navigation system may then be used to determine the position and orientation of the EM sensor within the patient, e.g., relative to anatomy of the patient, which is then indicative of the position and orientation of the distal end of the catheter relative to anatomy of the patient.

SUBSTITUTE SHEET (RULE 26) [OT33| A navigation guidewire including an EM sensor disclosed herein provides several advantages. For example, when used with a navigation guidewire, may not need an EM sensor, or to be retrofitted with an EM sensor. Also, a navigation guide wire may provide an indication of the position and orientation of a catheter within a patent without the use of fluoroscopy and associated radiation and contrast injection.

|0934] FIG. 1 is a conceptual diagram illustrating an example system 100 for delivering treatment to a patient through a vessel of a patient. Although example system 100 is described as a system for delivering ablation, such as cryoablation or PF A, system 100 is not so limited and may be an example of a system for delivering any treatment to a patient through a vessel of the patient. System 100 includes catheter 102, controller 104, and navigation guide wire 122. In general, to deliver a treatment (such as ablation), a practitioner (e.g., electrophysiologist, interventional cardiologist, etc.) may insert navigation guidewire 122 into a patient and navigate the navigation guidewire to a target tissue site within the patient. The practitioner may then insert one or more of catheter 102 into the patient and guide the catheter 102 to the target site via the navigation guidewire. The practitioner may then cause controller 104 to deliver, via catheter 102, energy (e.g., PFA energy, radiofrequency ablation energy, laser ablation, radio ablation, cryoablation energy, or the like) to target tissue of a patient. Ablation may cause lesions in target cardiac tissue which may mitigate or stop cardiac arrhythmias. In some examples, controller 104 may cause catheter 102 to deliver electroporation energy, e.g., PFA energy.

[ 00351 Catheter 102 may include elongated structure 112 including one or more energy delivery' elements 1 10. In the example shown, energy delivery⁷ element 110 is a cryoablation balloon. In other examples, energy delivery element 1 10 may include an electrode (e.g., in the case of a PFA catheter), a cryogenic element (e.g., in the case of a cryoablation catheter), a radiofrequency element (e.g., in the case of a radiofrequency ablation catheter), or another energy delivery' element. While the techniques of this disclosure are applicable to any ablation catheter, the example of FIG. 1 is directed to a cryoablation catheter 102. Catheter 102 may generally include features that enable insertion of catheter 102. into a patient and navigation of catheter 102 to a target tissue site. Elongated structure 112 may include a distal portion 106 and a proximal portion 108. Energy delivery element 110 may be generally positioned at distal portion 106, while proximal portion 108 may be connected to controller 104. Energy delivery element 1 10 may be of any suitable geometry'. Example geometries of electrodes

SUBSTITUTE SHEET (RULE 26) include, but are not necessarily limited to, a spheroid cryoablation balloon, a lobed cryoablation balloon, or PFA electrodes (not shown) such as circular (e.g., ring) electrodes surrounding the body of the catheter and/or a lead (e.g., a lead comprising electrodes and configured to deliver and/or receive electrical energy), conformable electrodes, cuff electrodes, segmented electrodes (e.g,, electrodes disposed at different circumferential positions around the circumference of the catheter and/or lead instead of a continuous ring electrode), or any combination thereof (e.g., ring electrodes and segmented electrodes). Energy delivery' element 1 10 may be axially distributed along longitudinal axis LA of elongated structure 1 12 or in several other configurations. In some examples, energy delivery element 110, as a balloon element, may be inflated when performing ablation and deflated when navigating catheter 102 to the target tissue. Energy delivery- element 110 may also be in a circular form, m an array, along multiple splines, or in other configurations. In some examples, elongated structure 112 may include conductors configured to carry electrical signals between energy delivery element 110 and controller 104.

[0036] Controller 104 may include an energy generator configured to provide cryogenic energy to energy delivery'’ elements 1 10 (or to control the delivery of PFA energy, or radio frequency energy, by energy delivery elements 110) to perform an ablation procedure to cardiac tissue or other tissues within the patient's body, such as renal tissue, airway tissue, and organs or tissue within the cardiac space or the pericardial space. For instance, the energy generator may be configured and programmed to deliver pulsed, high-voltage electric fields appropriate for achieving desired pulsed, high -voltage ablation, e.g., PFA, "‘pulsed electric field ablation,” and/or pulsed radiofrequency ablation. In the example shown, the energy generator may be configured and programmed for achieving desired cryogenic ablation.

[0037] Navigation guidewire 122 may include an elongated body configured to be inserted into a patient to a target tissue site and to guide catheter 102 to the target tissue site. For example, catheter 102 may include a lumen (e.g., within elongated structure 112) configured to receive navigation guidewire 122 and allow catheter 102 to be advanced within the patient along navigation guidewire 122 to the target tissue site. [0038] Navigation guidewire 122 may include and/or carry one or more electrodes, such as electrodes 124A and 124B (collectively, “electrodes 124”). Electrodes 124 maybe conductors (e.g., electrically conductive surfaces) configured to be used by controller 104 to sense electrical current and/or fields. Navigation guidewire 122 may include a

SUBSTITUTE SHEET (RULE 26) distal portion 126 and a proximal portion 128. Electrodes 12.4 may be generally positioned at distal portion 126, while proximal portion 128 may be connected to controller 104.

[0039| Electrodes 12.4 may be of any suitable geometry. Example geometries of electrodes include, but are not necessarily limited to, circular (e.g., ring) electrodes surrounding the core member of navigation guidewire 122, conformable electrodes, cuff electrodes, segmented electrodes (e.g., electrodes disposed at different circumferential positions around navigation guidewire 122 instead of a continuous ring electrode), or any combination thereof (e.g., ring electrodes and segmented electrodes). Electrodes 124 may be axially distributed along longitudinal axis LA of navigation guide wire 122. Electrodes 124 may also be in a circular form, in an array, along multiple splines, or in other configurations.

[0040J In some examples, electrodes 124 may include a tip electrode (e.g., electrode 124A), which may be a ring electrode with a “cap” covering at least a portion of a tip of navigation guidewire 122. In some examples, the tip electrode may be chamfered or otherwise rounded (e.g., to enable easier passage of navigation guidewire 122 through anatomy of the patient). Electrodes 124 may include a ring electrode (e.g., electrode 124B) that is adjacent to the tip electrode. This ring electrode may be separated (axially along LA) from the tip electrode. Electrodes 12.4 may include one or more pairs of ring electrodes (not. shown). A pair of ring electrodes may include two adjacently closely spaced electrodes of electrodes 124. In general, one or more pairs of ring electrodes of navigation guidewire 12.2 may be accompanied by one or more additional electrodes. The one or more additional electrodes may include any combination of pairs of ring electrodes and coil electrodes (e.g., electrodes that include conductors that spiral around navigation guide wire 122).

[0041] Navigation guidewire 122 may include and/or cany one or more EM sensors, such as EM sensor 132. EM sensor 132 may be an electrical conductor, an electromagnetic coil, a permanent magnet, a fluxgate, a wired induction sensor, or any suitable EM sensor configured to emit and/or receive electromagnetic energy, radiation, or fields. EM sensor 132. may be generally positioned at distal portion 126. EM sensor 132 may be on an outer surface of the elongate body of navigation guidew ire 122, or embedded within navigation guidewire 122 (e.g., within a hollow core navigation guidewire 12.2 or within a sidewall of the elongate body). One or more EM sensors 132 may be axially distributed along longitudinal axis LA of navigation guidewire 122. EM

SUBSTITUTE SHEET (RULE 26) sensor 132 may be configured to localize distal portion 126 of navigation guidewire 122 and/or to be indicative of a position and orientation of distal portion 126 of the elongate body of navigation guidewire 122, e.g., within a patient. In some examples, electrodes 124 may be positioned along distal portion 126 of the elongate body of navigation guidewire 122 at a predetermined and/or known distance and orientation relative to EM sensor(s) 132.

|0042] Navigation guidewire 12.2 may include signal wires, e.g., conductors, configured to carry electrical signals between electrodes 124, EM sensors 132, and controller 104. In some examples, navigation guidewire 122 may include a separate signal wire for each of electrodes 124 and EM sensors 132. For instance, in the example of FIG. 1 where electrodes 12.4 includes two electrodes and one EM sensor 132, navigation guidewire 122 may include three separate conductors. In this way, navigation guidew ire 122 may enable each electrode of electrodes 124 and EM sensor 132. to be driven by different signals from controller 104 and/or enable controller 104 to acquire different signals via different electrodes 124 and EM sensor 132. In other examples, multiple electrodes of electrodes 124 and multiple EM sensors 132 may share a common conductor. For instance, electrodes 124A and 124B and EM sensor 132 may be connected to a same (e.g., a common) conductor. Such an arrangement may reduce manufacturing complexity and/or cost and may increase the structural flexibility’ of navigation guidewire 122.

[O043| Navigation guidew ire 122 may comprise a hollow' core navigation guide wire. In some examples, the elongate body of navigation guide wire 122 may comprise a polymer having a hollow core. In some examples, navigation guidewire 122 may include the signal wires disposed within the hollow' core or embedded in the polymer material comprising the elongate body. In other examples, navigation guidewire 122 may comprise an elongate body comprising a solid core and a polymer layer or shell encapsulating the solid core. For example, the elongate body may comprise a nitinol with a polymer coating or shell, and signal wires may be embedded within the polymer coating or shell configured to cany electrical signals between electrodes 124 and controller 104. In some examples, the solid core may be a signal wire configured to carry electrical signals between electrodes 124, EM sensors 132, and controller 104.

[0044| In some examples, navigation guidewire 122 may include one or more proximal electrical connectors (not shown) configured to provide electrical connection

SUBSTITUTE SHEET (RULE 26) between the signal wires (conductors), electrical and/or thermal insulation, mechanical support, and reduce connector interference with the environment, e.g., catching or snagging on surgical drapes and/or other portions of the environment outside of the patient’s body. For example, navigation guidewire 122 may include an electrical connector configured to rotate around the elongate body of navigation guidewire 122.

In the example of FIG. 1, electrodes 124 and EM sensor 132 are illustrated as having a larger diameter than navigation guidewire 122. In some examples, one or more of electrodes 124 and EM sensor 132 may have a diameter that is approximately equal to or less than the diameter of navigation guidewire 122. For instance, electrodes 124 and EM sensor 132 may be recessed in navigation guidewire 122 such that the combination results in a relatively smooth outer surface of navigation guidewire 122. [0046| Controller 104 may include circuitry configured to receive and/or acquire electrical signals received by electrodes 124 and/or EM sensor 132. In some examples, based on received and/or acquired electrical signals received by electrodes 124 and/or EM sensor 132, controller 104 may be configured to localize and/or determine a position and/or orientation of distal portion 126 and of navigation guidewire 122 and distal portion 106 of catheter 102. For example, controller 104 may comprise processing circuitry and/or an electromagnetic navigation system configured to localize EM sensors 132 within a patient, and controller 104 may be configured to determine a position of distal portion 106 of catheter 102 relative to the localized EM sensors 132 based on signals from electrodes 124.

[ 00471 FIGS. 2A-2E are conceptual diagrams illustrating several example navigation guidewires 222A-222E including various arrangements of electrodes 124 and electromagnetic sensors 132. Navigation guidewires 222A-222E include elongated bodies 2I2.A-212E, respectively, and differing combinations electrodes 224A-224C (collectively, “electrodes 224”), and EM sensors 232A-232B (collectively, “EM sensors 232,” and which may be navigation coils 232). Navigation guidewires 222A-222E maybe substantially similar to navigation guidewire 122 described above, e.g., elongated bodies 212A-212.E (collectively, “elongate bodies 212”) may be configured to be inserted into a patient to a target tissue site and to guide catheter 102 to the target tissue site and may be configured to indicate a position and/or orientation of catheter 102 at or near the target tissue site. In some examples, elongate bodies 212 may comprise a polymer, a polyether, a urethane, or any combination thereof, e.g., an Elasthane ™, a Pell ethane®, a polyetheretherketone (PEEK), or the like. In some examples, elongate

SUBSTITUTE SHEET (RULE 26) bodies 212 may comprise nitinol, e.g., a hollow core nitinol . For example, a hollow core nitinol that may have outer and/or inner surfaces encapsulated within an electrically insulating material, such as a polymer or polymer coating.

[0ft48j In the examples shown, navigation guidewires 222A-222E each includes distal portion 226 and proximal portion 228, each of which may be substantially similar to proximal portion 126 and distal portion 128, respectively, described above.

Electrodes 224 may be substantially similar to electrodes 124 described above. In some examples, electrodes 22.4 may comprise gold, platinum, iridium, or any combination thereof

[00491 In the example shown in FIG. 2A, electrode 224A is disposed along distal portion 226 of elongate body 2I2A and distal to EM sensor 232A. In the example shown in FIG. 2B, electrode 224A is disposed along distal portion 2.26 of elongate body 2.12B and proximal to EM sensor 232A. In the example shown in FIG. 2C, electrode 224A is disposed along distal portion 226 of elongate body 212C and distal to EM sensor 232A and electrode 22.4B is disposed along distal portion 22.6 of elongate body 212C and proximal to EM sensor 232A. In some examples, having EM sensor 232A between a pair of electrodes 224 may increase an accuracy of determining a location and/or orientation of a distal portion 106 catheter 102 relative to navigation guidewire 222C. In the example shown in FIG. 2D, EM sensor 232A is disposed along distal portion 226 of elongate body 212D and distal to electrode 224A and EM sensor 232B is disposed along distal portion 226 of elongate body 212C and proximal to electrode 224A. In some examples, having electrode 224A between a pair of EM sensors 232 may increase an accuracy of determining a curvature, location, and/or orientation of a distal portion 106 catheter 102 relative to navigation guidewire 2221). In the example shown in FIG. 2E, distal portion 226 of elongate body 212E includes a plurality of alternating electrodes 224 and EM sensors 232, e.g,, electrode 224A distal to EM sensor 232A, which is distal electrode 224B, which is distal to EM sensor 232B, which is distal to electrode 224C. In some examples, having a plurality of alternating electrodes 224 and EM sensors 232 may increase an accuracy of determining a curvature, location, and/or orientation of a distal portion 106 catheter 102 relative to navigation guidewire 222E.

[0050J FIGS. 3A-3C are perspective view's of a distal portion 326 of an example navigation guidewire 322. FIG. 3A is a perspective view' of distal portion 326 of navigation guidewire 32.2, FIG, 3B is a transparent, perspective view of distal portion 326 of navigation guidewire 322 illustrating internal components of the navigation guidewire,

SUBSTITUTE SHEET (RULE 26) and FIG. 3C is a transparent, perspective view of a cross-section of distal portion 326 of navigation guidewire 322 illustrating internal components of the navigation guidewire. Navigation guidewire 322 may be an example of any of navigation guidewires 222 A- 222E, 122 described above.

[0051. J In the examples shown, navigation guidewire 322 includes electrodes 324A, 324B (collectively, ‘"electrodes 324”) disposed along distal portion 326 of elongated body 312. Distal portion 326 of navigation guidewire 322 also includes atraumatic tip 314. In some examples, distal portion 326 may include a floppy tip (not shown), and in the other examples, distal portion 326 may be flexible, but non-floppy. In some examples, tip 314 may comprise a thermoplastic polyurethane (TPU), e.g., a printed TPU tip 314.

[0052| In the example shown, elongated body 312 is a hollow core elongate body, and electrodes 224A and 224B are electrically connected to signal wires 344A and 344B, respectively, which are disposed within the hollow’ core of elongate body 312. In the example shown, navigation guidewire 32.2 also includes EM sensor 332. and signal wires 334A and 334B electrically connected to EM sensor 332 and disposed within the hollow' core of elongate body 312.

[0053 J Signal wires 334A, 334B, 344A, 344B comprise an electrically conductive material, and may be configured to be connected to a signal and/or power source at a proximal portion of navigation guidewire 322. For example, a proximal portion of navigation guidewire 322 may be configured to be connected to controller 104, e.g., signal wires 334A, 334B, 344A, 344B may be connected to controller 104 via a single and/or multiple conductor connection cable and/or connector (not. shown). For example, system 100 may include navigation guidewire 322 and a proximal connection cable and/or connector configured to be slid over a portion of a proximal portion of navigation guidewire 322 and electrically connect and/or engage with signal wires 334A, 334B, 344A, 344B to connect one or more of electrodes 324A, 324B and/or EM sensor 332 to a signal or power source, e.g., controller 104. In some examples, the proximal connector may be configured to provide electrical insulation and/or isolation as well as mechanical insulation, isolation, and/or support of proximal termination points or ends of signal wires 334A, 334B, 344A, 344B, e.g., to insulate and cover the proximal ends of signal wires 334A, 334B, 344A, 344B. In some examples, the proximal connector may be a permanently connected electrical cable or connector, or the proximal connector may be a detachable electrical cable or connector. In some examples, electrodes 324A, 324B

-12-

SUBSTITUTE SHEET (RULE 26) and/or EM sensor 332 may be configured to be wirelessly connected to a power and/or signal source, e.g., via a wireless power and/or signal interface.

[0054 In the example shown, EM sensor 332 is configured to be disposed within elongate body 312, e.g., in some examples, embedded within the material of elongate body 312, and in other examples within the hollow core of elongate body 312. For example, EM sensor may have a diameter that is less than or equal to 0.3 mm and a length that is less than or equal to 2.5 mm, and may fit within an inner diameter of hollow core elongate body 312. Elongate body 312 may be an example of elongate body 212 or the elongate body of navigation guidewire 122 described above, electrodes 324 maybe examples of electrodes 224 or 124 described above, and EM sensor 332 may be an example of EM sensors 232 or 132 described above.

[0055| FIGS. 4 A- -4C are cross-sectional views of a di stal portion 42.6 of an example navigation guidewire 422. FIG. 4A is a cross-sectional view of distal portion 426 of navigation guidewire 422, FIG. 4B is a cross-sectional view of distal portion 426 of navigation guidewire 42.2 along the line B-B as shown in FIG. 4A, and FIG. 4C is a cross-sectional view of distal portion 426 of navigation guide wire 422 along the line A- A as shown in FIG. 4A. Navigation guidewire 422 may be an example of any of navigation guidewires 322, 222A-222E, 122 described above. In the examples shown, example dimensions are in inches.

In the example shown, navigation guidewire 422 includes elongate body 412, which may be an example of any of elongate bodies 312, 212, or the elongate body of navigation guidewire 122 described above. In the example shown, elongate body 412 is a hollow' core body and includes hollow' core 404. Navigation guidewire 422 also includes tip 414, which may be an example of tip 314 described above. In the example shown, tip 414 is an atraumatic button shaped tip and includes step portion 415. Tip 414 and stem portion 415 may be adhered to elongate body 412 along one or more surfaces of tip 414 and step portion 415 by an adhesive 402. Distal portion 426 of navigation guidewire 422 may also include recess 416. Recess 416 may be configured to receive an electrode, e.g., a ring electrode, such that another surface of the electrode is coplanar with the outer surface of elongate body 412, e.g., surface 419 as shown. Recess 416 includes inner surface 417, and a radial distance from surface 417 to surface 419 may correspond to a radial thickness of an electrode configured to be disposed along distal portion 426 of navigation guidewire 422.

SUBSTITUTE SHEET (RULE 26) [0057| In the example shown, elongate body 412 also includes slot 418. Slot 418 may be configured to allow a signal wire to be connected to an electrode disposed within recess 416. For example, a signal wire may nm through hollow' core 404 and pass through slot 418 to be in electrical contact with the electrode.

[D058| In some examples, distal portion 426 of guidewire 422 may include one or more EM sensors (not shown) and one or more additional recesses and slots configured to receive one or more additional electrodes and signal wires (not shown). For example, distal portion 426 may include one or more recesses and slots located proximal to recess 416.

[00591 FIGS. 5A is a partially transparent side view of a distal portion 526 of navigation guide wire 522, FIG. 5B is a partially transparent side view of a distal portion 626 of navigation guidewire 622, and FIG. 5C is a cross-sectional view' of distal portion 626 of navigation guidewire 622. Navigation guidewire 522 may be an example of any of navigation guidewire 422 described above, and navigation guidewire 622 may be an example of any of navigation guidewires 222A-222E, 122 described above.

In the example shown in FIG. 5A, navigation guidewire 522 includes elongate body 512, which may be an example of any of elongate body 412, or the elongate body of navigation guidewire 122 described above. In the example shown, elongate body 512 is a hollow' core body and includes EM sensor 532. Navigation guidewire 522 also includes tip 514, which may be an example of tips 414, 314 described above, e.g., including a stem portion 515 which may be an example of step portion 415. In the example shown, tip 514 is an atraumatic button shaped tip and tip 514 and stem portion 515 may be adhered to elongate body 512 along one or more surfaces of tip 514 and step portion 515 by an adhesive (not shown). Distal portion 526 of navigation guidewire 522 also includes electrode 524A, which may be disposed in a recess (not shown) of elongate body 512 which may be the same as recess 416 described above and may include a slot similar to slot 418. Distal portion 526 of navigation guidewire 522 also includes electrode 524B, which may be disposed in another recess (not show'll) of elongate body 512 proximal to electrode 524A and which may be similar to recess 416 described above and a slot similar to slot 418. In the example shown, electrodes 524A, 524B are ring electrodes.

[00611 In the examples shown in FIGS. 5B and 5C, navigation guidewire 622 includes elongate body 612, which may be an example of any of elongate bodies 412 or the elongate body of navigation guidew ire 122 described above. In the example shown,

SUBSTITUTE SHEET (RULE 26) elongate body 612 is a hollow core body and includes EM sensor 632. Navigation guidewire 622 also includes electrode 624A, which is a tsp electrode. In the example shown, elongate body 612 may include atip recess similar to recess 418 described above, except terminating at the distal tip of elongate body 612. The recess may or may not include a slot 618A similar to slot 418. For example, elongate body 612 may have a distal opening providing access to electrode 624A for signal wires to electrically connect to electrode 624A. Electrode 62.4A may be an atraumatic tip and may have a curved shape, such as the hemispherical shape shown in FIGS. 5B and 5C,

[0062] Distal portion 626 of navigation guidewire 622 also includes electrode 624B, which may be disposed in another recess of elongate body 612 proximal to electrode 624A and which may be similar to recess 416 described above and a slot 618B which may be similar to slot 418. In the example shown, electrode 624B is a ring electrode.

[0063] FIG. 6 is a flow diagram illustrating an example method of localizing a catheter within a patient. FIG. 6 is described with respect to navigation guidewire 122 and catheter 102. of FIG. 1 and FIGS. 7A-7D, as well as the representations of navigation guidewire 122 and catheter 102 of FIGS. 7E-7H. FIGS. 7A-7D are a series of partially transparent side views of navigation guidewire 122 at different stages of localizing navigation guide wire 122 and catheter 102 according to the method of FIG. 6, and FIGS. 7E-7H are a series of representations of portions of catheter 102 localized at the stages corresponding to FIGS. 7A-7E and according to the method of FIG. 6.

Although described with respect to navigation guidewire 122 and catheter 102, the techniques of FIG. 6 may be utilized with different guidewires and/or catheters, e.g., navigation guides wires 222A-222E, 322, 422, 522, and 622.

[0064] A clinician may move navigation guidewire 122 through a vessel of a patient to a target treatment site (702). A clinician may also move a catheter 102 through the vessel of the patient to the target treatment site (704). In some examples, the clinician may move navigation guidewire to the target treatment site before catheter 102, and use navigation guidewire 122 to guide catheter 102 to the target treatment site, e.g., by advancing catheter 102 ‘’over” navigation guidewire 122 disposed within a lumen of catheter 102. In other examples, the clinician may move catheter 102 to the target treatment before moving navigation guidewire 122, e.g., by advancing navigation guidew ire 122 through a lumen of catheter 102. For example, catheter 102 may be moved by itself to the target treatment site, or over a different guidewire (e.g., a non -navigation guidewire), and then navigation guidewire 122 may be advanced through the lumen of

SUBSTITUTE SHEET (RULE 26) catheter 102. In some examples, the clinician may move navigation guidewire 122 and catheter 102 together, or at the same time, to the target treatment site. In some examples, the clinician may move navigation guidewire 122 and catheter 102 to be near to, or approximately in the location of, the target treatment site at method steps (702) and (704), and the clinician may subsequently adjust to the positions of catheter 102 and navigation guidewire 122 at any of the method steps of the method of FIG. 6.

[0065 J Processing circuitry, via EM sensor 132, may determine a position and an orientation of the distal portion 126 (FIG. 1) of the elongate body of navigation guidewire 122 (706). Processing circuitry, based on the position and the orientation of distal portion 126 of the elongate body of navigation guidewire 122, a position and an orientation of distal portion of catheter 102 (708). For example, processing circuitry of controller 104 may determine a position of EM sensor 132 based on signals from EM sensor 132 and signals from electrode 124B as navigation guidewire 122 is moved relative to catheter 102, e.g., advancing or retracting distal portion 126 of navigation guidewire 122 out of or into catheter 102 (e.g., a lumen of catheter 102) as illustrated in FIGS. 7A-7H.

[0066| For example, once positioned at or near a target treatment site, the clinician may position navigation guidewire 122 such that EM sensor 132 and electrode 124B are advanced distally past the distal end of catheter 102 and out of a lumen of catheter 102, as shown in FIG. 7A. Processing circuitry of controller 104 may determine a position of EM sensor 132 based on signals generated by EM sensor 132 and received by controller 104, and may output to the clinician, e.g., via a user interface such as user interface 520 (FIG. 8) a representation 732 of EM sensor 132 indicative of its position and shown in FIG. 7E. Tire processing circuitry may also determine that electrode 124B is outside of the lumen of catheter 102 based on signals generated by electrode 124B and received by controller 104, e.g., an electrical impedance of electrode 124B.

[0067] The clinician may then retract navigation guidewire 122 in the proximal direction to be within the lumen of catheter 102 while processing circuitry receives signals from EM sensor 132 and electrode 124B. FIGS. 7B-7D illustrate three different positions of navigation guidewire 122 relative to catheter 102 as navigation guidewire 122 is retracted within the lumen in the proximal direction . At a first retracted position shown in FIG. 7B, electrode 124B is retracted within the lumen of catheter 102 while EM sensor 132 is still out of the lumen. As electrode 124B enters the lumen, the impedance of electrode 124B may change, e.g., due to changes in the geometry of the vessel that it is m, that is, from the vessel of the patient to the lumen of catheter 102. The processing

SUBSTITUTE SHEET (RULE 26) circuitiy’ may determine the position of EM sensor 132 at the time of the impedance change of electrode 124B, and determine that the electrode 124B is entering, or has entered, the lumen when EM sensor is at that determined position. Processing circuitry may then determine a position of the distal end of catheter 102 relative to the position of EM sensor 132 (and distal portion 126 of navigation guidewire 122) based on the impedance change of electrode 124B and a known (predetermined) and fixed distance between EM sensor 132 and electrode 124B. Processing circuitry may output, via the user interface, a representation 732 of EM sensor 132 and a representation 712 of elongated structure 112 of catheter 102 indicative of the positions of EM sensor 132 and the distal end of catheter 102, as shown in FIG. 7F. For example, processing circuitry may determine the position and orientation of catheter 102 based on the positions and orientations of EM sensor 132 and electrodes 12.4B and 124A, and “'paint” a representation of the position and orientation of catheter 102 such as illustrated in FIGS. 7F-7H, and output the representation to a user interface.

In some examples, electrodes 124A and 124B may not be “visible” using a navigation system, e.g., electrodes 124A and 124B may generate a navigation signal (e.g., be visible on an EM navigation system) outside of the lumen of catheter 102, but may not generate a navigation signal (e.g., not be visible on an EM navigation sy stem) when inside of the lumen of catheter 102. In some examples, EM sensor 132 may generate a signal (e.g., be visible on an EM navigation system) whether inside or outside of the lumen of catheter 102.

[0069| At a second retracted position shown in FIG. 7C, electrode 124B, EM sensor 132, and electrode 124A are all retracted within the lumen of catheter 102. As electrode 124A enters the lumen, the impedance of electrode 124A may change, e.g., due to changes in the geometry of the vessel that it is in, that is, from the vessel of the patient to the lumen of catheter 102, which may provide confirmation of the position of the distal end of catheter 102 (e.g., that catheter 102 has not moved relative to navigation guidewire 122). For example, the processing circuitry may determine the position of the distal end of catheter 102 relative to the position of EM sensor 132 (and distal portion 126 of navigation guidewire 12.2) based on the impedance changes of electrode 124A and 124B and a known (predetermined) and fixed distance between EM sensor 132 and electrode 124B and a known (predetermined) and fixed distance between EM sensor 132 and electrode 124A. In the example shown, processing circuitry’ may’ also determine a position and orientation of an energy delivery element 110 of catheter 102, e.g., based on

SUBSTITUTE SHEET (RULE 26) the positions of EM sensor 132, the determined position of the distal end of catheter 102, and a known (predetermined) distance from the distal end of catheter 102 and energy delivery element 110.

[D070[ lire processing circuitry' may determine a plurality of positions of EM sensor 132 (e.g,, track EM sensor 132) as navigation guidewire 122 is retracted relative to catheter 102. The processing circuitry- may output, via the user interface, a representation 732 of EM sensor 132 and a representation 712 of elongated structure 112 (including more of the longitudinal length of the distal portion 106 of elongated structure 112 of catheter 102), and a representation 710 of energy delivery⁷ element 110, as shown in FIG . 7G. At a third retracted position shown in FIG. 7D, navigation guidewire 122 is further retracted within the lumen and processing circuitry may continue to track tire positions of EM sensor 132 and determine further positions and orientations of catheter 102 along its length, and output representation 732 of EM sensor 132, representation 712 including still more of the longitudinal length of the distal portion 106 of elongated structure 112 of catheter 102, and representation 710 including more of energy- delivery⁷ element 110, as shown in FIG. 7H.

[00711 Although shown as straight in the longitudinal direction in FIGS. 7A-7H, navigation guidewire 122 and catheter 102 may be curved along their longitudinal length, e.g,, within a curved vessel of the patient of vasculature of the patient that follows a tortuous path. For example, processing circuitry⁷ may determine a curvature of distal portion 126 of navigation guidewire 122 and distal portion 106 of catheter 102, e.g., including energy delivery element 110. In some examples, processing circuitry may determine aposition, orientation, and an angle of the end face of the distal end of catheter 102 relative to a vessel wall of the patient, e.g., based on the positions of EM sensor 132 and impedances of electrodes 124A and 124B. For example, processing circuitry may map out the location and curvature of the longitudinal axis of catheter 102, including at the distal end of catheter 102, and determine if the end face of the distal end of catheter 102 is tilted towards a vessel w alk

[0072} In some examples, the processing circuitry may determine a position and orientation of distal portion 126 of a navigation guidewire and catheter 102, and an angle of the distal end face of catheter 102, based on a plurality of EM sensors. For example, the clinician may use a navigation guidewire 222E including multiple EM sensors, e.g., EM sensors 232A and 2.32B, with the method of FIG. 6. Processing circuitry' may determine the position and orientation (e.g., including curvature) as described above, but

SUBSTITUTE SHEET (RULE 26) based on both EM sensors 232A and 232B, which may be at a known (predetermined) distance to each other along navigation guidewire 222E. Processing circuitry' may determine a curvature of catheter 102 with improved accuracy based on multiple EM sensors (e.g., position trackers) spaced at known (predetermined) distances.

[0073| FIG. 8 is a block diagram illustrating an example controller 804 of a navigation system configured for use with a navigation guidewire. Controller 804 of FIG. 8 may be an example of controller 104 of FIG. 1. As shown in FIG. 8, controller 804 may include energy generator 816, processing circuitry’ 818, user interface 820, storage devices 822, and sensing circuitry 824.

H)074| Energy generator 816 may be configured to provide cryogenic energy to energy delivery elements (e.g., energy delivery elements 110 of FIG. I) to perform a therapeutic procedure, e.g., to cardiac tissue or other tissues within the patient's body, such as renal tissue, airway tissue, and organs or tissue within the cardiac space or the pericardial space. In some examples, energy delivery’ elements 110 may be PFA electrodes, and energy’ generator 816 may be configured and programmed to deliver pulsed, high-voltage electric fields appropriate for achieving desired pulsed, high- voltage ablation (referred to as ‘‘pulsed field ablation” or “pulsed electric field ablation”) and/or pulsed radiofrequency ablation. While shown in the example of FIG. 8 as a single energy’ generator, energy generator 816 is not so limited. For instance, controller 804 may include multiple energy generators that are each capable of generating ablation signals in parallel .

[0075| Processing circuitry 818 may include one or more processors, such as any one or more of 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 functions attributed to processing circuitry’ 818 herein may’ be embodied as firmware, hardware, software or any combination thereof. Processing circuitry' 818 controls energy generator 816 to generate signals according to various settings (e.g., linear settings 830 or focal settings 832). In some examples, processing circuitry 818 may execute other instructions stored in storage device 822 to perform a therapeutic procedure, e.g., cryogenic ablation, PFA, or any suitable therapeutic procedure.

[0076 | Sensing circuitry 824 may be configured to receive signals from energy delivery-’ elements 110, electrodes of a navigation guidewire (e.g., electrodes 12.4, 224,

SUBSTITUTE SHEET (RULE 26) 324, 524, 624), or EM sensors of the navigation guidewire (e.g., EM sensors 132, 232, 332, 532, 632).

[0077 | Storage device 822 may be configured to store information within controller 804, respectively, during operation. Storage device 822 may include a computer- readable storage medium or computer-readable storage device. In some examples, storage device 822 includes one or more of a short-term memory or a long-term memory. Storage device 822 may include, for example, random access memories (RAM), dynamic random access memories (DRAM), static random access memories (SRAM), magnetic discs, optical discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable memories (EEPROM). In some examples, storage device 822 is used to store data indicative of instructions, e.g., for execution by processing circuitry 818, respectively. [00781 User interface 820 may include a button or 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. User interface 820 may be configured to display any information related to the performance of a therapeutic procedure, e.g., cryoablation, PFA. Elser interface 820 may also receive user input via user interface 820. The user input may be, for example, in the form of pressing a button on a keypad or selecting an icon from a touch screen. [00791 Accordingly, although example systems and techniques have been shown and described, it is to be understood that all the terms used herein are descriptive rather than limiting, and that many changes, modifications, and substitutions may be made by one having ordinary skill in the art without departing from the spirit and scope of the invention. The following examples are examples of systems, devices, and methods described herein.

[0080| Example 1: A guidewire including: an elongate body; an electromagnetic (EM) sensor disposed along a distal portion of the elongate body, wherein the electromagnetic sensor is configured to be indicative of a position and orientation of the distal portion of tire elongate body; and an electrode disposed along the distal portion of the elongate body at a predetermined distance and orientation relative to the electromagnetic sensor, [00811 Example 2: The guidewire of example 1, wherein the electrode is disposed along the distal portion of the elongate body and distal to the electromagnetic sensor.

SUBSTITUTE SHEET (RULE 26) [0082[ Example 3: The guidewire of any of examples 1 and 2 or any of examples 1 and 2, wherein the electrode is disposed along the distal portion of the elongate body and proximal to the electromagnetic sensor.

[00831 Example 4: The guidewire of any one of examples 1-3, wherein the EM sensor comprises a navigation coil,

[0984] Example 5: The guide wire of any one of examples 1-4, wherein the electrode is a first electrode, wherein the predetermined distance and orientation is a first predetermined distance and a first predetermined orientation, the guidewire further including: a second elec trode that is disposed along the distal portion of the elongate body and proximal to the electromagnetic sensor at a second predetermined distance relative to tire electromagnetic sensor and a second orientation relative to the electromagnetic sensor.

[00851 Example 6: The guide wire of any one of examples 1-5. wherein the guidewire comprises a non-floppy, atraumatic tip.

[0086] Example 7: The guidewire of any one of examples 1-6, wherein the electrode is configured to be indicative of a distal end of a catheter.

[00871 Example 8: The guidew ire of any one of examples 1-7, wherein the electrode is configured to have an impedance change upon entering or exiting a lumen of a catheter. [00881 Example 9: A medical system including: a catheter; and a navigation guidewire includes an elongate body; an electromagnetic (EM) sensor disposed along a distal portion of the elongate body, wherein the electromagnetic sensor is configured to be indicative of a position and orientation of the distal portion of the elongate body; and an electrode disposed along the distal portion of the elongate body at a predetermined distance and orientation relative to the electromagnetic sensor.

[0089| Example 10: Hie medical system of example 9, wherein the electrode is disposed along the distal portion of the elongate body and distal to the electromagnetic sensor.

[0990] Example 11: The medical system of any of examples 9 and 10 or any of examples 9 and 10, wherein the electrode is disposed along the distal portion of the elongate body and proximal to the electromagnetic sensor,

[00911 Example 12: The medical system of any one of examples 9-11, wherein the EM sensor comprises a navigation coil.

[0092] Example 13: The medical system of any one of examples 9-12, wherein the electrode is a first, electrode, wherein the predetermined distance and orientation is a

SUBSTITUTE SHEET (RULE 26) first predetermined distance and a first predetermined orientation, the navigation guidewire further including: a second electrode that is disposed along the distal portion of the elongate body and proximal to the electromagnetic sensor at a second predetermined distance relative to the electromagnetic sensor and a second orientation relative to the electromagnetic sensor.

[0093] Example 14: The medical system of any one of examples 9-13, wherein the navigation guidewire comprises a non-floppy, atraumatic tip.

|0094] Example 15: The medical system of any one of examples 9-14, wherein the electrode is configured to be indicative of a. distal end of the catheter.

[0095] Example 16: The medical system of any one of examples 9-15, wherein the electrode is configured to have an impedance change upon entering or exiting a lumen of a catheter.

[0096] Example 17: The medical system of any one of examples 9-15, wherein the catheter comprises a cryoablation balloon catheter.

[0097] Example 18: A method of localizing a catheter within a patient, the method including: moving a guidewire through a vessel of a patient to a target treatment site, wherein the guidewire comprises: an elongate body; an electromagnetic (EM) sensor disposed along a distal portion of the elongate body, wherein the electromagnetic sensor is configured to be indicative of a position and orientation of the distal portion of the elongate body; and an electrode disposed along the distal portion of the elongate body at a predetermined distance and orientation relative to the electromagnetic sensor; moving a catheter through the vessel of the patient to the target treatment site; determining, via processing circuitry and the electromagnetic sensor, a position and an orientation of the distal portion of the elongate body of the guidewire; and determining, via the processing circuitry and based on the position and the orientation of the distal portion of the elongate body of the guidewire, a position and an orientation of a distal end of the catheter.

10998] Example 19: The method of example 18, wherein the catheter and guidewire are moved together to the target treatment site.

[0099] Example 20: The method of any of examples 18 and 19 or any of examples 18 and 19, wherein determining the position and the orientation of the distal end of the catheter comprises: advancing or retracting the electrode out of or into a lumen of the catheter while determining, via the electromagnetic sensor, the position and the orientation of the distal portion of the elongate body of the guidewire.

SUBSTITUTE SHEET (RULE 26) Example 21 : The method of example 20, wherein determining the position and the orientation of the distal end of the catheter comprises: determining an impedance change of the electrode when the electrode is advanced or retracted out of or into the lumen of the catheter.

[D191| Example 22: The method of any one of examples 18-21, wherein the electrode is a first electrode, wherein the predetermined distance and orientation is a first predetermined distance and a first predetermined orientation, the guidewire further including a second electrode that is disposed along the distal portion of the elongate body and proximal to the electromagnetic sensor at a second predetermined distance relative to tire electromagnetic sensor and a second orientation relative to the electromagnetic sensor, wherein determining the position and the orientation of the distal end of the catheter comprises: advancing or retracting both the first electrode and tire second electrode out of or into a lumen of the catheter while determining, via the electromagnetic sensor, the position and the orientation of the distal portion of the elongate body of the guidewire.

[0H>2] Example 23: The method of any one of examples 18-22, wherein determining the position and the orientation of the distal end of the catheter comprises determining a curvature of a distal portion of the catheter.

[0103 j Example 24: The method of any one of examples 18-23, wherein determining the position and the orientation of the distal end of the catheter comprises determining an angle of an end face of the catheter relative to a vessel wall of the patient.

[0104| Example 25: The method of any one of examples 18-24, wherein the EM sensor comprises a navigation coil.

[0105] Example 26: The method of any one of examples 18-25, wherein the catheter comprises a cryoablation balloon catheter.

[0106] The techniques described in this disclosure may be implemented, at least in part, in hardware, software, firmw are or any combination thereof. For example, various aspects of the described techniques may be implemented within processing circuitry, which 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 combinations of such components. The term ‘’processor” or “processing circuitry” may generally refer to any of the foregoing logic circuitry, alone or in combination with other logic circuitry, or any other equivalent circuitry. A control

SUBSTITUTE SHEET (RULE 26) unit including hardware may also form one or more processors or processing circuitry configured to perform one or more of the techniques of this disclosure.

[01071 Such hardware, software, and firmware may be implemented, and various operation may be performed within same device, within separate devices, and/or on a coordinated basis within, among or across several 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 separately as discrete but interoperable logic devices. Depiction of 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 realized by separate hardware or software components. Rather, functionality associated with one or more circuits or units may be performed by separate hardware or software components or integrated within common or separate hardware or software components. Processing circuitry described in this disclosure, including a processor or multiple processors, may be implemented, in various examples, as fixed-function circuits, programmable circuits, or a combination thereof. Fixed- function circuits refer to circuits that provide particular functionality with preset operations. Programmable circuits refer to circuits that can be programmed to perform various tasks and provide flexible functionality in the operations that can be performed. For instance, programmable circuits may execute software or firmware that cause the programmable circuits to operate in the manner defined by instructions of the software or firmware. Fixed-function circuits may execute software instructions (e.g., to receive stimulation parameters or output stimulation parameters), but the types of operations that the fixed-function circuits perform are generally immutable. In some examples, one or more of the units may be distinct circuit blocks (fixed-function or programmable), and in some examples, one or more of the units may be integrated circuits,

[ 0I08| The techniques described in this disclosure may also be embodied or encoded in a computer-readable medium, such as a computer-readable storage medium, containing instructions that may be described as non-transitory media. Instructions embedded or encoded m a computer-readable storage medium may cause a programmable processor, or other processor, to perform the method, e.g., when the instructions are executed. Computer readable storage media may include random access memory (RAM), read only memory' (ROM), programmable read only memory-' (PROM), erasable programmable read only memory (EPROM), electronically erasable

24-

SUBSTITUTE SHEET (RULE 26) programmable read only memory' (EEPROM), flash memory, a hard disk, a CD-ROM, a floppy disk, a cassette, magnetic media, optical media, or other computer readable media.

SUBSTITUTE SHEET (RULE 26)

Claims

WHAT IS CLAIMED IS:

1 . A guidewire comprising: an elongate body; an electromagnetic (EM) sensor disposed along a distal portion of the elongate body, wherein the electromagnetic sensor is configured to be indicative of a position and orientation of the distal portion of the elongate body; and an electrode disposed along the distal portion of the elongate body at a predetermined distance and orientation relative to the electromagnetic sensor.

The guide wire of claim 1, wherein the electrode is disposed along the distal portion of the elongate body and distal to the electromagneti c sensor.

3. lire guidewire of claim 1 or claim 2, wherein the electrode is disposed along the distal portion of the elongate body and proximal to the electromagnetic sensor.

4. The guidewire of any one of claims 1-3, wherein the EM sensor comprises a navigation coil.

5. The guidewire of any one of claims 1-4, wherein the electrode is a. first electrode, wherein the predetermined distance and orientation is a first predetermined distance and a first predetermined orientation, the guidewire further comprising: a second electrode that is disposed along the distal portion of the elongate body and proximal to the electromagnetic sensor at a second predetermined distance relative to the electromagnetic sensor and a second orientation relative to the electromagnetic sensor.

6. The guidewire of any one of claims 1-5, wherein the guidewire comprises a nonfloppy, atraumatic tip.

7. The guidewire of any one of claims 1 -6, wherein the electrode is configured to be indicative of a distal end of a catheter.

-26-

SUBSTITUTE SHEET (RULE 26)

8. The guidewire of any one of claims 1-7, wherein the electrode is configured to have an impedance change upon entering or exiting a lumen of a catheter,

9. A medical system comprising: a catheter; and a navigation guidewire comprising: an elongate body; an electromagnetic (EM) sensor disposed along a distal portion of the elongate body, wherein the electromagnetic sensor is configured to be indicative of a position and orientation of the distal portion of the elongate body; and an electrode disposed along the distal portion of the elongate body at a predetermined distance and orientation relative to the electromagnetic sensor.

10. lire medical system of claim 9, wherein the electrode is disposed along the distal portion of the elongate body and distal to the electromagnetic sensor.

1 1 . The medical system of claim 9 or claim 10, wherein the electrode is disposed along the distal portion of the elongate body and proximal to the electromagnetic sensor.

12. The medical system of any one of claims 9-11, wherein the EM sensor comprises a navigation coil .

13. The medical system of any one of claims 9-12, wherein the electrode is a first electrode, wherein the predetermined distance and orientation is a first predetermined distance and a first predetermined orientation, the navigation guide wire further comprising: a second electrode that is disposed along the distal portion of the elongate body and proximal to the electromagnetic sensor at a second predetermined distance relative to the electromagnetic sensor and a second orientation relative to the electromagnetic sensor.

14. The medical system of any one of claims 9-13, wherein the navigation guide wire comprises a non-floppy, atraumatic tip,

SUBSTITUTE SHEET (RULE 26) wherein the electrode is configured to be indicative of a distal end of the catheter, and wherein the electrode is configured to have an impedance change upon entering or exiting a lumen of a catheter.

15. The medical system of any one of claims 9-14, wherein the catheter comprises a cryoablation balloon catheter.

SUBSTITUTE SHEET (RULE 26)