Electrode deactivation to prevent energy delivery to blood pool

Abstract

A system includes: a catheter configured to deliver pulsed field ablation (PFA) energy to patient tissue via a plurality of electrodes; and processing circuitry configured to: for each electrode, determine a location of the electrode based on two or more of: an impedance measurement; a sensed cardiac signal; or one or more of a tracked catheter location or a tracked electrode location; and based on the determination of the location of the electrode, determine whether to activate delivery of PFA energy via the electrode, wherein the processing circuitry activates delivery of PFA energy when the location of the electrode is in contact with patient tissue and when the location of the electrode meets a minimum threshold distance from one or more sensitive structures; and deliver PFA energy to patient tissue via electrodes of the plurality of electrodes through which delivery of PFA energy has been activated.

Description

Docket No.: A0013501W001 / 1289-032W001 ELECTRODE DEACTIVATION TO PREVENT ENERGY DELIVERY TO BLOOD POOL AND SENSITIVE STRUCTURES

[0001] This application claims the benefit of U.S. Provisional Application Serial No.63 / 779,846, filed March 28, 2025, entitled “ELECTRODE DEACTIVATION TO PREVENT ENERGY DELIVERY TO BLOOD POOL AND SENSITIVE STRUCTURES” which is hereby incorporated by reference in its entirety.TECHNICAL FIELD

[0002] This disclosure generally relates to guiding ablation of cardiac tissue.BACKGROUND

[0003] Various procedures have been developed to analyze, diagnose and / or treat various organ systems including electrophysiological conditions of the cardiovascular system, central nervous system or peripheral nervous system. For example, cardiac ablation is a procedure that may be employed to treat an irregular heart rhythm, such as atrial fibrillation (AF). Cardiac ablation may involve alteration of heart tissue to disrupt generation and / or propagation of faulty electrical signals causing the arrhythmia. Ablation devices may include catheters with one or more electrodes. The electrodes may be configured to apply energy to ablate target tissue, such as through a respective ablation modality, e.g., pulsed field ablation (PF A), cryoablation, and radio frequency (RF) ablation, to cause a lesion in the tissue to, for example, block unwanted propagation of electrical signals.SUMMARY

[0004] In general, this disclosure describes example medical devices, systems, and techniques for automatically deactivating and / or recommending deactivating one or more electrodes of a plurality of electrodes of an ablation catheter, e.g., a pulsed field ablation (PF A) catheter or a cryoablation catheter, based on a location of the electrodes. In some examples, the location of the electrode may be relative to one or more of patient tissue, blood pool, or one or more sensitive structures. The devices and systems herein may be configured to sense and / or receive one or more signals and / or data to determine a location of each electrode of the plurality of electrodes. For each electrode, based on the location, the devices and systems described herein may determine whether to deactivate the electrode. In some examples, if the location of the electrode is not in contact with patient tissue or if the electrode is within a threshold distance from a sensitive structure, e.g., an atrioventricular (AV) node of a patient, the system mayDocket No.: A0013501W001 / 1289-032W001 determine to deactivate delivery of PF A energy via the electrode (e.g., deactivate the electrode). The system may deliver ablation energy via electrodes through which delivery of PF A energy has not been deactivated (e.g., electrodes that have not been deactivated).

[0005] In some examples, the system may determine which electrodes to activate (e.g., activate delivery of PF A energy via the determined electrodes) based on the location of each electrode. If the location is in contact with patient tissue and the electrode meets a minimum threshold distance from the sensitive structure, the system may activate the electrode. The system may deliver ablation energy via the activated electrodes.

[0006] In some examples, the location of each electrode may be a location of the electrode relative to patient tissue and / or a location of the electrode relative to a sensitive structure. In some examples, if the electrode is not in contact with the patient tissue, the electrode may be in contact with the patient blood pool. To determine the location of each electrode of the plurality of electrodes, the techniques of this disclosure include determining the location based on two or more of a tracked electrode location and / or a tracked catheter location, an impedance measurement, or a cardiac electrogram (EGM).

[0007] In examples described herein, a medical system includes one or more catheters, e.g., a PFA catheter and / or a cryoablation catheter, and processing circuitry operably coupled to the one or more catheters. The PFA catheter may be configured to sense a cardiac EGM of a patient and / or measure an impedance of a patient. The medical system includes processing circuitry operably coupled to energy delivery elements, e.g., electrodes and / or cry o-refrigerant jets, of the catheter. The processing circuitry is configured to control energy delivery and electrode deactivation / activation based on the location information, e.g., the impedance measurement, the cardiac EMG, and / or the tracked electrode location and / or the tracked catheter location.

[0008] The processing circuitry can automatically deactivate delivery of therapy (e.g., PFA) via selected electrodes or activate delivery of therapy via selected electrodes (e.g., deactivate / activate electrodes) based on the location information. In some examples, the processing circuitry may generate an output for user review indicative of a recommendation of which electrodes to deactivate / activate. In some examples, the user, e.g., a clinician, can provide input indicative of a preference with respect to whether the system automatically deactivates / activates electrodes or if the processing circuitry generates the output indicative of the recommendation.

[0009] In one example, a system includes: a catheter configured to deliver pulsed field ablation (PFA) energy to patient tissue via a plurality of electrodes; and processing circuitry configured to: for each electrode of the plurality of electrodes of the catheter, determine a location of the electrode relative to one or more of the patient tissue, blood pool, or one or moreDocket No.: A0013501W001 / 1289-032W001 sensitive structures based on two or more of: an impedance measurement; a sensed cardiac signal; or one or more of a tracked catheter or a tracked electrode location and for each electrode of the plurality of electrodes, based on a determination that the location of the electrode is not in contact with the patient tissue, that the location of the electrode is primarily in contact with the blood pool, or that the location of the electrode is within a threshold distance from one or more sensitive structures, determine to deactivate delivery of PF A energy via the electrode; and deliver PFA energy to patient tissue via electrodes of the plurality of electrodes through which delivery of PF A energy has not been deactivated.

[0010] In another example, a method includes: for each electrode of a plurality of electrodes of a catheter configured to deliver pulsed field ablation (PFA) energy to patient tissue via the plurality of electrodes, determining a location of the electrode relative to one or more of the patient tissue, blood pool, or one or more sensitive structures based on two or more of: an impedance measurement; a sensed cardiac signal; or one or more of a tracked catheter location or a tracked electrode location; and for each electrode of the plurality of electrodes, based on a determination that the location of the electrode is not in contact with the patient tissue, that the location of the electrode is primarily in contact with the blood pool, or that the location of the electrode is within a threshold distance from one or more sensitive structures, determining to deactivate delivery of PFA energy via the electrode; and delivering PFA energy to patient tissue via electrodes of the plurality of electrodes through which delivery of PFA energy has not been deactivated.

[0011] In another example, a system includes: a catheter configured to deliver pulsed field ablation (PFA) energy to patient tissue via a plurality of electrodes; and processing circuitry configured to: for each electrode of the plurality of electrodes of the catheter, determine a location of the electrode based on two or more of: an impedance measurement; a sensed cardiac signal; or one or more of a tracked catheter location or a tracked electrode location; and based on the determination of the location of the electrode, determine whether to activate delivery of PFA energy via the electrode, wherein the processing circuitry activates delivery of PFA energy via the electrode when the location of the electrode is in contact with patient tissue and when the location of the electrode meets a minimum threshold distance from one or more sensitive structures; and deliver PFA energy to patient tissue via electrodes of the plurality of electrodes through which delivery of PFA energy has been activated.

[0012] The details of one or more examples of the techniques of this disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques will be apparent from the description and drawings, and from the claims.Docket No.: A0013501W001 / 1289-032W001BRIEF DESCRIPTION OF DRAWINGS

[0013] FIG. l is a partially conceptual diagram illustrating an example system to deliver ablation energy as well as to detect and / or sense signals, in accordance with one or more aspects of this disclosure.

[0014] FIG. 2A and FIG. 2B are conceptual diagrams illustrating examples of ablation catheters configured to deliver ablation energy and / or measure signals, in accordance with one or more aspects of this disclosure.

[0015] FIG. 3 is a block diagram illustrating an example interface unit and anatomical information device(s) of an ablation system, in accordance with one or more aspects of this disclosure, in accordance with one or more aspects of this disclosure.

[0016] FIG. 4 is a flowchart illustrating an example operation for deactivating delivery via electrodes of a pulsed field ablation (PF A) catheter based on a location of the electrodes, in accordance with one or more techniques of the disclosure.

[0017] FIG. 5 is a flowchart illustrating an example operation for activating delivery via electrodes of a PFA catheter based on a location of the electrodes, in accordance with one or more techniques of the disclosure.

[0018] FIG. 6 is a flowchart illustrating an example operation for determining through which electrodes delivery is to be deactivated based on location in response to a hemolysis risk level meeting a threshold, in accordance with one or more techniques of the disclosure.

[0019] FIG. 7 is a flowchart illustrating an example operation for determining a risk of hemolysis based on a number of applications of PFA energy, in accordance with one or more techniques of the disclosure.

[0020] FIG. 8 is a flowchart illustrating an example operation for determining through which electrodes delivery is to be deactivated based on electrode location in response to a location of the PFA catheter being which a threshold distance from a sensitive structure, in accordance with one or more techniques of the disclosure.

[0021] FIG. 9 is a flowchart illustrating an example operation for determining whether to deactivate delivery via an electrode based on the location of the electrode relative to one or more of patient tissue, a patient blood pool, or one or more sensitive structures, in accordance with one or more techniques of the disclosure.

[0022] FIG. 10 is a flowchart illustrating an example operation for updating an activation state of an electrode based on an updated electrode location, in accordance with one or more techniques of the disclosure.

[0023] FIG. 11 is a graphical representation of an amount of plasma free hemoglobin relative to a number of applications of PFA energy when electrodes are in contact with patient tissue andDocket No.: A0013501W001 / 1289-032W001 when electrodes are not in contact with patient tissue, in accordance with one or more techniques of this disclosure.DETAILED DESCRIPTION

[0024] This disclosure describes example devices, systems, and techniques relating to medical device systems, including systems used during medical procedures, such as ablation of tissue, e.g., cardiac tissue, to treat one or more conditions, e.g., arrhythmias. In such ablation procedures, therapy in the form of energy can be delivered to one or more regions of tissue via devices, e.g., catheters, at discrete locations. Energy can include pulsed field (PF) energy, cryogenic energy, e.g., cryoablation, radiofrequency (RF), microwave, laser, another suitable therapy, and / or a combination thereof configured to treat one or more patient conditions. In some examples, energy can include combinations of therapeutic modalities, such that the system or a user toggles between different therapeutic energy delivery modalities and / or such that multiple modalities are delivered together. This disclosure describes example devices, systems, and techniques for delivering ablation energy, e.g., PF energy and / or cryoablation, via a subset of available therapy delivery elements, e.g., electrodes or cryoballoons, based on a location of each respective therapy delivery element. For example, a system may automatically deactivate one or more electrodes (e.g., deactivate delivery of therapy via the one or more electrodes) of a plurality of electrodes on a catheter based on the location of the electrode(s). Electrodes of the plurality of electrodes that are in contact with patient tissue may be activated or remain active, and electrodes that are not in contact with patient tissue, e.g., electrodes that are primarily in contact with the blood pool, or electrodes that are within a threshold distance from a sensitive structure, such as an atrioventricular node (AV) or sinoatrial (SA) node of a patient, may be deactivated or not activated. That is, the system may activate delivery of therapy through electrodes of the plurality of electrodes that are in contact with patient tissue and / or may deactivate delivery of therapy through electrodes that are within a threshold distance from a sensitive structure, such as an AV node of a patient and electrodes that are primarily in contact with the blood pool of the patient.

[0025] The devices and systems herein may be configured to sense and / or receive one or more signals and / or data to determine a location of each electrode of the plurality of electrodes. For each electrode, based on the location, the systems described herein may determine whether to deactivate delivery of therapy through the electrode, e.g., deactivate the electrode. In some examples, if the location of the electrode is not in contact with patient tissue or if the electrode is within a threshold distance from a sensitive structure, e.g., an AV or SA node of a patient, the system may determine to deactivate the electrode. The system may deliver ablation energy via electrodes that have not been deactivated. Deactivating the electrode may be considered asDocket No.: A0013501W001 / 1289-032W001 deactivating the delivery of therapy (e.g., PF A) via that electrode for the relevant portion of the pulse train (even when the pulse train would typically provide energy via that electrode during that portion of the pulse train), and activating the electrode may be considered as activating the delivery of therapy (e.g., PF A) via that electrode for the relevant portion of the pulse train.

[0026] In some examples, the system may determine which electrodes to activate based on the location of each electrode. If the location is in contact with patient tissue and the electrode meets a minimum threshold distance from the sensitive structure, the system may activate the electrode. The system may deliver ablation energy via the activated electrodes. In some examples, the system may deliver the ablation energy to treat atrial fibrillation (AF). In some examples, the minimum threshold distance may vary based on energy settings of the PFA system. When the energy settings are relatively low, each application of PFA energy may be associated with less hemolysis and / or damage. Thus, in some examples, if the energy settings are relatively low, the minimum threshold distance may be relatively high. If the energy settings are relatively high, the minimum threshold distance may be relatively low.

[0027] In some examples, the location of each electrode may be a location of the electrode relative to patient tissue, a location of the electrode relative to a patient blood pool, and / or a location of the electrode relative to a sensitive structure. In some examples, if the electrode is not in contact with the patient tissue, the electrode may be in contact with the patient blood pool. To determine the location of each electrode of the plurality of electrodes, the techniques of this disclosure include determining the location based on two or more of a tracked catheter location and / or a tracked electrode location, an impedance measurement, or a cardiac electrogram (EGM). The efficacy of a given treatment can be reduced if the given treatment adversely affects neighboring tissue or other anatomical features that might be sensitive to the treatment.Additionally, delivering ablation energy to a blood pool of a patient can lead to hemolysis, which may cause adverse effects for the patient. By deactivating electrodes that are near sensitive structures and electrodes that are primarily in contact with the blood pool, the techniques of this disclosure may prevent (e.g., reduce, limit, or stop) adverse effects to the sensitive structures and may prevent hemolysis or decrease an amount of hemolysis, thereby improving patient outcomes.

[0028] The example techniques may provide advantages relative to other ablation systems. For instance, some ablation systems do not deactivate electrodes and / or deliver ablation energy via a subset of electrodes based on the location of the electrodes. Instead, some ablation systems use all available electrodes. In some cases, some systems may provide an indication of a location of a catheter and / or the electrodes for user review. Based on this indication of the location of the catheter and / or the electrodes, the user may determine to move the catheter. This manipulation of the catheter is cumbersome relative to the techniques of this disclosure. Additionally,Docket No.: A0013501W001 / 1289-032W001 manipulating the catheter as opposed to deactivating a subset of the electrodes may result in longer procedure times, which may lead to adverse patient outcomes. Moreover, these systems for determining electrode location are relatively inaccurate and / or imprecise compared to the techniques of this disclosure.

[0029] The techniques of this disclosure include determining electrode locations using two or more factors such as an impedance measurement, a cardiac EGM, or a tracked catheter location and / or a tracked electrode location. By determining electrode locations using two or more factors, the techniques of this disclosure may be more accurate than other systems, such as systems that determine location based on only one factor. Due to the increased accuracy of the electrode location determinations, clinicians may be more likely to feel comfortable to choose to deactivate electrodes and / or allow the system to automatically deactivate electrodes using the techniques of this disclosure. Therefore, in addition to improving patient outcomes by preventing hemolysis and / or adverse effects to sensitive structures, the increased accuracy of the location determination allows clinicians to use the systems, devices, and techniques described here with confidence. Clinicians may be more likely to use systems, devices, and techniques described herein than other systems due to the increased accuracy of the location determination. Clinicians may not choose and / or may not feel comfortable choosing to deactivate electrodes based on location using previous systems due to the relative inaccuracy and / or imprecision of previous systems.

[0030] In some examples, the system described herein is configured to perform location mapping to track the catheter location and / or the catheter location. In some examples, a single catheter may be configured to both deliver ablation energy via one or more of PF A or cryoablation and to perform the location mapping using a technique such as ICE. The single catheter configured for both ablation energy delivery and location mapping may be a more elegant and less cumbersome solution than previous ablation systems involving multiple catheters. Additionally, by limiting the number of catheters involved in the ablation therapy, the techniques of this disclosure may reduce a risk of complications associated with multi-catheter procedures, such as entanglement of the catheters, which can lead to adverse patient outcomes.

[0031] The techniques of this disclosure may include automatically deactivating / activating electrodes based on the location information. In some examples, the processing circuitry may generate an output for user review indicative of a recommendation of which electrodes to deactivate / activate. In some examples, the user, e.g., a clinician, can provide input indicative of a preference with respect to whether the system automatically deactivates / activates electrodes or if the processing circuitry generates the output indicative of the recommendation.Docket No.: A0013501W001 / 1289-032W001

[0032] FIG. l is a conceptual diagram illustrating an example system to deliver ablation energy as well as to detect and / or sense signals, in accordance with one or more aspects of this disclosure. In some examples, the system is configured to delivery ablation energy to treat atrial fibrillation (AF) or another arrhythmia. System 100 includes a catheter 102 (e.g., a minimally invasive ablation catheter configured to navigate into a heart of a patient and treat cardiac arrhythmias), an interface unit 104, and an anatomical information device(s) 107. System 100 may be configured to deliver ablation therapy, as well as map and / or record signals from a patient 101. In general, to deliver ablation therapy, a user (e.g., clinician, electrophysiologist, interventional cardiologist, etc.) may insert one or more of catheter 102 into patient 101 and cause interface unit 104 to deliver, via catheter 102, energy (e.g., ablation energy) to tissue 103 of patient 101. In some examples, ablation energy is delivered to multiple areas to create multiple lesions. For example, a clinician may use interface unit 104 to cause ablation energy to be delivered via catheter 102 resulting in multiple overlapping lesions.

[0033] Ablation energy (which may otherwise be referred to as ablation therapy) may include one or more of pulsed field ablation (PF or PF A) energy, cryoablation or cryogenic ablation energy, radiofrequency (RF) ablation energy, laser ablation, thermal ablation, microwave energy, carbon ion beam ablation, ultrasound energy, and / or another suitable energy and / or therapy. In some examples, delivered ablation energy includes combinations of different types of energy (e.g., such that the system or a user toggles between different energy modalities, and / or such that multiple energy modalities are delivered together). Ablation may cause lesions in tissue 103 (e.g., cardiac tissue) which may mitigate, stop, and / or prevent cardiac arrhythmias or other types of patient conditions.

[0034] In some examples, catheter 102 is configured to deliver ablation therapy to tissue 103. In some examples, catheter 102 includes one or more therapy delivery elements 110 (shown individually as therapy delivery element 110A and therapy delivery element HOB and collectively referred to herein as therapy delivery elements 110). Each of therapy delivery elements 110 may include an electrode (e.g., in the case of a RF or PFA catheter), a cryogenic element (e.g., in the case of a cryoablation catheter), an ultrasound transducer (e.g., in the case of an ultrasound catheter), or another suitable therapy delivery element. In some examples, therapy delivery elements 110 are disposed on, or carried by, an elongated structure 112 of catheter 102. As ablation causes lesions to tissue 103, it may be desirable for a system to determine a location of catheter 102 and therapy delivery elements 110, e.g., electrodes or cryogenic elements, of catheter 102. In some examples, system 100 may be configured to activate delivery of therapy via electrodes and / or deactivate delivery of therapy via electrodes based on the location of the electrodes relative to tissue 103, patient 101’s blood pool, and / or one or more sensitive structuresDocket No.: A0013501W001 / 1289-032W001 of patient 101, such as an AV or SA node of patient 101. In some examples, system 100 may be configured to activate delivery of therapy and / or deactivate delivery of therapy or otherwise adjust delivery of therapy based on one or more characteristics of tissue 103. As an example, system 100 may determine a thickness of tissue 103 based on one or more of impedance data, computed tomography data, magnetic resonance imaging data, and / or intracardiac echocardiography data. In some examples, system 100 may activate therapy delivery elements of therapy delivery elements 110 disposed near relatively thick patient tissue and may deactivate therapy delivery elements of therapy delivery elements 110 disposed near relatively thin patient tissue.

[0035] Catheter 102 may generally include features that enable insertion of catheter 102 into patient 101, as well as navigation of catheter 102 to a target tissue site (e.g., adjacent tissue 103). In some examples, elongated structure 112 includes a distal portion 106 and a proximal portion 108. Therapy delivery elements 110 may be positioned at distal portion 106, while a proximal portion 108 may be connected to interface unit 104. Proximal portion 108 may be configured to be positioned outside of the body of the patient while the distal portion 106 is positioned within the body the patient (e.g., during a period of ablation therapy).

[0036] Therapy delivery elements 110 may be of any suitable geometry. In examples, where therapy delivery elements 110 include one or more electrodes, geometries of electrodes include, but are not necessarily limited to, circular (e.g., ring) electrodes surrounding the body of catheter 102, conformable electrodes, cuff electrodes, segmented electrodes (e.g., electrodes disposed at different circumferential positions around catheter 102 instead of a continuous ring electrode), or any combination thereof (e.g., ring electrodes and segmented electrodes). In some examples, catheter 102 includes an expandable structure at distal portion 106. In some examples, therapy delivery elements 110 are disposed on the expandable structure. In some examples, one or more of therapy delivery elements 110 includes an expandable structure (e.g., an expandable lattice structure formed from a conductive material).

[0037] Therapy delivery elements 110 may be axially distributed along longitudinal axis LA of elongated structure 112 or in several other configurations. In some examples, catheter 102 may include one or more therapy delivery elements 110 positioned at different axial and radial positions relative to elongated structure 112. In some examples, therapy delivery elements 110 are disposed around an expandable structure (e.g., a balloon, basket, splines, etc.), which may be expanded when performing ablation and compressed when navigating catheter 102 to tissue 103. The therapy delivery elements 110 may also be in a circular form, in an array, along multiple splines, or in other configurations. In some examples, as discussed previously, catheter 102 includes an expandable structure. In some examples, the expandable structure includes a selfDocket No.: A0013501W001 / 1289-032W001 expanding structure. In some examples, the expandable structure is manually activated (e.g., via pullwire, inflation, or another suitable expansion mechanism).

[0038] In some examples, system 100 includes one or more sensors 111 (shown individually as sensor 111 A and sensor 11 IB and collectively referred to herein as sensors 111). Sensors 111 may be configured to detect, sense, and / or transmit information about patient 101 and / or operating parameters of system 100. For example, interface unit 104 may be configured to receive signals that indicate one or more measurable parameters associated with catheter 102 and / or therapy delivered via catheter 102, including one or more of temperature, voltage, delivered current, and / or tissue contact. In some examples, interface unit 104 may be configured to receive signals corresponding to one or more characteristics of tissue 103, such as temperature of tissue 103, electrogram (EGM) waveforms, monophasic action potentials, impedance (e.g., tissue impedance), or the like. Interface unit 104 may be configured to monitor, record, or otherwise receive measurements or conditions via sensors 111 of catheter 102, other components of system 100, and / or the ambient environment at the distal portion of the energy delivery device (e.g., from tissue 103 of patient 101). Sensors 111 may be in communication with interface unit 104 for initiating or triggering one or more alerts or ablation energy delivery modifications during operation of the energy delivery device. In some examples, sensors 111 may be part of interface unit 104, and / or anatomical information device(s) 107. In some examples, e.g., in examples in which therapy delivery elements 110 comprise electrodes, sensors 111 and therapy delivery elements 110 may each be configured for sensing, e.g., sensing tissue contact and / or a cardiac EGM, and for therapy delivery. For example, when system 100 is configured to pulsed field ablation (PF A), system 100 may deliver PF A via any combination of therapy delivery elements 110 and sensors 111. In some examples, sensors 111 may be distinct from therapy delivery elements 110.

[0039] In some examples, elongated structure 112 includes conductors (e.g., wires, trace elements, and / or the like) configured to carry electrical signals between therapy delivery elements 110 and interface unit 104 as well as between sensors 111 and interface unit 104. In some examples, elongated structure 112 may include a separate conductor for each of therapy delivery elements 110 and / or for each of sensors 111. In the example of FIG. 1, where system 100 includes two therapy delivery elements 110, elongated structure 112 may include two separate conductors. In this way, elongated structure 112 may enable each of therapy delivery elements 110 to be driven with a different signal from interface unit. In other examples, multiple therapy delivery elements 110 may share a common conductor. For instance, therapy delivery element 110A and therapy delivery element HOB may be connected to a same (e.g., a common) conductor.Docket No.: A0013501W001 / 1289-032W001

[0040] In some examples, interface unit 104 is configured to couple to a therapy generator configured to provide therapy (e.g., electrical energy, cryogenic therapy, or another suitable form of therapy, and / or a combination thereof) to therapy delivery elements 110 to perform an ablation procedure to tissue 103 of patient 101. In other examples, interface unit 104 and a therapy generator are part of a single capital system. In some examples, tissue 103 includes cardiac tissue, such as tissue proximate the pulmonary vein, or tissue within a chamber of the heart. While the examples discussed in this disclosure are primarily in the context of cardiac tissue, tissue 103 can include any suitable tissue within the patient’s body, such as renal tissue, airway tissue, and other organs. 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., “pulsed field ablation” or “pulsed electric field ablation”) and / or pulsed or non-pulsed radiofrequency ablation. In some examples, the energy generator may be configured and programmed for achieving desired cryogenic ablation. In some examples, the energy generator is configured as an acoustic generator and programmed to deliver ultrasound energy, such as for achieving ultrasound ablation.

[0041] In some examples, interface unit 104 includes a positioning subsystem configured to track and record positions of one or more of catheter 102, therapy delivery elements 110, sensors 111, or other suitable components of system 100. In some examples, the positioning subsystem is configured to track one or more of catheter 102, therapy delivery elements 110, and / or sensors 111 via an electromagnetic signal, injected current signals, fluoroscopy, or the like. In some examples, interface unit includes one or more of an electromagnetic signal and / or electromagnetic field generator, a generator to inject current, and / or another mapping / navigation system for tracking a position of one or more of catheter 102, therapy delivery elements 110, and / or sensors 111. In some examples, one or more portions of catheter 102, therapy delivery elements 110, and / or sensors 111 are radiopaque and may be tracked via a suitable imaging modality. In some examples, sensors 111 include accelerometers or other sensors (e.g., position sensors, such as electromagnetic coils) configured to facilitate tracking of relative movement of sensors 111 or movement relative to a reference position. In some examples, sensors 111 include force sensors, which may be configured to sense force (e.g., contact force) and / or pressure between at least a portion of catheter 102 and tissue 103. In some examples, the positioning subsystem is additionally or alternatively configured to measure, determine, and / or record biophysical information (e.g. cardiac EGM signal, such as cardiac EGM signal amplitudes, impedance, temperature) indicative of location.

[0042] As discussed in other portions of this disclosure, the positioning subsystem of interface unit 104 may enable and / or facilitate deactivation / activation of one or more of therapyDocket No.: A0013501W001 / 1289-032W001 delivery elements 110, as the positioning subsystem can provide a location of a portion of catheter 102 (e.g., therapy delivery elements 110 and / or sensors 111) throughout a period of ablation therapy. Interface unit 104 may automatically deactivate / activate delivery of therapy through one or more of therapy delivery elements 110 based on the location of the one or more therapy delivery elements relative to one or more of tissue 103, patient 101’s blood pool, or a sensitive structure of patient 101, e.g., the AV node of patient 101. Activation of a therapy delivery element 110 (e.g., an electrode) may refer to activation of delivery of therapy via that therapy delivery element 110, and deactivation of a therapy delivery element 110 (e.g., an electrode) may refer to deactivation of delivery of therapy via that therapy delivery element 110.

[0043] In some examples, one or more sensors 111 of the catheter 102 (e.g., at distal portion 106) include position sensors for enabling interface unit 104 to track the position, as well as a shape and / or an orientation, of therapy delivery elements 110. In some examples, therapy delivery elements 110 comprise electrodes configured to delivery therapy and to measure an impedance and / or sense a cardiac EGM. In some examples, one or more position sensors 111 and / or therapy delivery elements 110 of catheter 102 include sensors configured to determine a location of therapy delivery elements 110 and / or sensors 111. In some examples, one or more of sensors 111 or therapy delivery elements 110 are configured to sense one or more signals or one or more fields, such as (but not limited to) electromagnetic signals, electromagnetic fields, magnetic fields, or another suitable position tracking signal or field. For example, an electromagnetic position sensor may include one or more induction coils that induce a current to detect signals emanating from electromagnetic field generators. One or more coils for determining position with five or six degrees of freedom can be used. The magnetic field detected by the electromagnetic position sensor may be used to determine the location (e.g., position, orientation, and / or shape) of a portion of catheter 102, such as distal portion 106 and therapy delivery elements 110, according to one or more methods commonly known in the art such as, for example, methods based on using a magnetic sensor to sense magnetic fields and using a look-up table to determine location of the magnetic position sensor. Accordingly, because other portions of catheter 102, including elongated structure 112, therapy delivery elements 110 and / or other sensors 111 may have a fixed relationship to the magnetic position sensor, the magnetic position sensor may also provide the location (e.g., position, orientation, and / or shape) these other portions of catheter 102. Other position sensing methods can additionally or alternatively be used. For example, the location (e.g., position, orientation, and / or shape) of therapy delivery elements 110 and / or sensors 111 can be determined based on two or more of a tracked catheter location and / or a tracked electrode location, an impedance measurement, or a cardiac EGM.Docket No.: A0013501W001 / 1289-032W001

[0044] In some examples, interface unit 104 includes a user interface 105. In some examples, user interface 105 includes a screen, display, and / or another visual output medium (e.g., augmented reality display or virtual reality display). In some examples, user interface 105 includes a button or keypad, lights, a speaker for voice commands, and the display can include one or more of a liquid crystal (LCD), light-emitting diode (LED), or organic light-emitting diode (OLED) display.

[0045] In some examples, interface unit 104 is configured to generate and present (e.g., display), via user interface 105, information about one or more of patient 101, tissue 103, catheter 102, therapy delivered to tissue 103 via therapy delivery elements 110, and / or signals sensed by sensors 111. In some examples, interface unit 104 is configured to generate and present (e.g., display), via user interface 105, a representation of tissue 103 of patient 101. The representation of tissue can include a portion of an organ (e.g., a heart) of patient 101. For example, the representation of tissue can include a “shell” representing the boundary of an organ (e.g., the heart of patient 101). In some examples, interface unit 104 is configured to generate and present (e.g., display), via user interface 105, a representation of catheter 102, therapy delivery elements 110, and / or sensors 111. The representation of catheter 102, therapy delivery elements 110, and / or sensors 111 may enable a user (e.g., a clinician) to determine a spatial relationship between tissue 103 and catheter 102 (e.g., one or more of distal portion 106, therapy delivery elements 110, and / or sensors 111). For example, interface unit 104 may enable a user (e.g., a clinician) to know which portion of tissue 103 is in contact with catheter 102, which may indicate where therapy will be delivered during a period of therapy delivery via therapy delivery elements 110. In some examples, interface unit 104 may enable a user (e.g., a clinician) to know a distance between one or more portions of catheter 102 and tissue 103 (e.g., in examples where one or more portions of catheter 102 is not touching a portion of tissue 103).

[0046] In some examples, anatomical information device(s) 107 includes one or more devices that enable visualization of portions of tissue 103 of patient 101. Anatomical information device(s) 107 can additionally or alternatively enable virtualization of one or more portions of catheter 102. In some examples, anatomical information device(s) include one or more of an ultrasound device, a computed tomography (CT) device, a magnetic resonance imaging (MRI) device, a pacing device, an electrophysiology (EP) mapping device, and / or a non-invasive mapping device. Anatomical information device(s) 107 may be used by system 100 to inform interface unit 104 of the anatomy of a patient, as well as physical and / or electrical characteristics of the anatomy, and / or a location of catheter 102 during delivery of catheter 102 into the anatomy of a patient. In some examples, interface unit 104 may include one or more of anatomical information device(s) 107. In some examples, anatomical information device(s) 107 provide orDocket No.: A0013501W001 / 1289-032W001 otherwise enable interface unit 104 to generate a representation of tissue 103 of patient 101. In some examples, interface unit 104 is configured to receive anatomical information from anatomical information device(s) 107 and generate, based on the anatomical information, the representation of tissue (e.g., tissue 103).

[0047] In some examples, interface unit 104 is configured to identify, e.g., based on information from anatomical information device(s) 107, sensors 111, and / or therapy delivery elements 110, sensitive structures (e.g., areas of tissue 103, such as the AV node) and generate indications of the sensitive structures to a user (e.g., a clinician). In some examples, sensitive structures include areas of tissue 103 where ablation therapy is to be avoided, e.g., the AV node the SA node, nerves, such as a phrenic nerve and a vagus nerve, coronaries, the conduction system just beyond each of the SA node and the AV node, or collateral organs, such as the esophagus, the lungs, or bronchi. In some examples, a coughing response of patient 101 may decrease when the bronchi are avoided. In some examples, interface unit 104, based on information from anatomical information device(s) 107, is configured to determine a location of a sensitive structure, and generate (e.g., via user interface 105) an indication of the location of the sensitive structure to a user (e.g., a clinician). Information of the location of sensitive structures relative to other tissue of tissue 103 can enable a clinician to avoid delivery of ablation therapy to such sensitive structures. System 100 may automatically deactivate delivery of therapy via therapy delivery elements of therapy delivery elements 110 that are within a threshold distance from a sensitive structure.

[0048] In some examples, interface unit 104, which may be configured for ablating a portion of tissue 103 (e.g., a target tissue area or volume) of a patient 101, includes memory configured to store at least one of anatomical information of a patient or physiological information (e.g., temperature, impedance, and / or cardiac electrophysiological information) of patient 101.Interface unit 104 may be configured to generate and present (e.g., display), via user interface 105, indications of energy delivered to tissue 103 of patient 101 (e.g., via therapy delivery elements 110 of catheter 102). As discussed herein, a continuous period of therapy delivery may include a period during which an ablation waveform is being generated and applied via a catheter, where this ablation waveform has one or more predetermined pauses between ablation pulses (e.g., pauses between pulses of PF A). As discussed herein, a period of continuous application of ablation therapy to the tissue can include a period of time of ablation therapy (e.g., energy) delivered to portion of tissue 103. In some examples, the period of continuous application of ablation therapy to the tissue is a predetermined period of discrete length (e.g., about 1 second to about 10 seconds, such as about 5 seconds). In some examples, the period of continuous application of ablation therapy is predetermined, and / or controlled by processingDocket No.: A0013501W001 / 1289-032W001 circuitry of interface unit 104. In some examples, the period of continuous ablation therapy is not predetermined, and controlled by user (e.g., clinician) input, such as input to interface unit 104. In some examples, the period of continuous application of ablation therapy includes delivery of a waveform of energy that may have short pauses between pulses of energy.

[0049] In some examples, interface unit and / or catheter 102 are configured to deliver ablation to multiple locations over multiple instances of ablation (e.g., multiple periods of continuous application of ablation therapy). Each instance of therapy delivery may be defined by the period of continuous application of ablation therapy. In some examples, a user (e.g., a clinician) initiates each instance of therapy delivery via a control (e.g., button) on one or more of catheter 102 and / or interface unit 104.

[0050] In some examples, processing circuitry of interface unit 104 is configured to receive information indicative of movement of catheter 102. In some examples, processing circuitry of interface unit 104 receives the information indicative of movement of catheter 102 during a period of continuous ablation therapy, such that processing circuitry of interface unit 104 updates which therapy delivery elements of therapy delivery elements 110 are activated (e.g., through which therapy delivery elements 110 therapy can be delivered) and deactivated (e.g., through which therapy delivery elements 110 therapy cannot be delivered) during the period of continuous ablation therapy. The information indicative of movement of catheter 102 may be based on signals from catheter 102 and / or signals from a positioning subsystem of interface unit 104. In some examples, information indicative of movement of catheter 102 includes a change in a signal (an impedance signal, a cardiac EGM signal, a temperature signal, a current signal, a power signal, a force signal, a contact force signal, another suitable signal, and / or a combination thereof) indicative of movement of catheter 102 (e.g., movement of distal portion 106 of catheter 102 relative to tissue 103).

[0051] For example, changes in impedance that indicate movement of catheter 102 can be sensed by one or more of therapy delivery elements 110 and / or sensors 111 and received by the positioning subsystem of interface unit 104. As another example, changes in temperate indicative of movement of catheter 102 can be sensed by thermocouples at a distal portion (e.g., a distalmost portion, as illustrated in FIG. 2A and FIG. 2B) of catheter 102. In some examples, one or more signals (e.g., impedance signal, temperature signal, EGM signal, a force signal, a contact force signal, position signal, another suitable signals, and / or a combination thereof) indicate contact between a portion of catheter 102 (e.g., therapy delivery elements 110 and / or sensors 111) and tissue 103. In some examples, a change in a signal (e.g., an impedance signal, a temperature signal, a current signal, a power signal, an EGM signal, a force signal, a contact force signal, another suitable signals, and / or a combination thereof) reflects catheter 102Docket No.: A0013501W001 / 1289-032W001 contacting a different part of tissue 103. In some examples, a change in a signal (e.g., change in impedance measurement, temperature signal, EGM signal, another suitable signals, and / or a combination thereof) reflects catheter 102 (e.g., distal portion 106) moving from a position in which catheter 102 is in contact with, or at least in relatively close proximity to, tissue 103 to a position in which catheter 102 (e.g., distal portion 106) is not in contact with, or a relatively further proximity from, tissue 103.

[0052] While the example of FIG. 1 is primarily discussed in the context of a single catheter 102 configured for both therapy delivery and sensing, the techniques of this disclosure may include using two or more separate catheters, e.g., a catheter to deliver ablation energy and a separate diagnostic catheter. For example, a first catheter (e.g., a mapping or diagnostic catheter), can be inserted into patient 101 to detect and measure information (e.g., location mapping data indicative of tracked electrode and / or catheter locations, impedance data, cardiac EGM data, temperature data) about tissue 103 of patient 101. A second catheter (e.g., catheter 102) can be inserted into patient 101 to perform an ablation procedure, e.g., to target tissue identified by the first catheter, which may be a portion of tissue 103 as shown in the example of FIG. 1.Additionally or alternatively, while the example of FIG. 1 shows all of therapy delivery elements 110 on a single catheter 102, some of therapy delivery elements 110 can be disposed and / or carried by another catheter (e.g., like catheter 102) or another suitable structure. For example, a second, different catheter (e.g., like catheter 102) can be inserted into patient 101 (e.g., into a heart of patient 101, outside of heart of patient 101, or at another suitable location), such that therapy is delivered by and / or between therapy delivery elements 110 disposed on and / or carried by each of the first catheter 102 and the second catheter. In some examples, system 100 additionally or alternatively includes one or more external reference electrodes and / or ground patches, e.g., such that therapy is delivered between therapy delivery elements 110 of one or more of catheter 102 and the one or more external reference electrode and / or one or more ground patches. In some examples, therapy is delivered between delivery elements 110 of one or more of catheter 102 and an internal patch (e.g., in epicardium).

[0053] FIG. 2A and FIG. 2B are conceptual diagrams illustrating examples of ablation catheters configured to deliver ablation energy and / or measure signals, in accordance with one or more aspects of this disclosure. FIG. 2A and FIG. 2B are conceptual diagrams illustrating example ablation and / or mapping catheters. Catheter 202 of FIG. 2A and catheter 252 of FIG. 2B are each examples of catheter 102 described above in relation to FIG. 1. Components of catheter 202 and catheter 252 may have the same or similar characteristics and functions as described above for ablation catheter 102. Catheter 202 of FIG. 2A and catheter 252 of FIG. 2B mayDocket No.: A0013501W001 / 1289-032W001 additionally be examples of other catheters described in this disclosure (e.g., catheter 402, catheter 502, catheter 602, catheter 702, and / or catheter 802).

[0054] FIG. 2A illustrates ablation catheter 252 that may be configured for ablation therapy, sensing, and / or mapping. Catheter 252 may be configured to pass through vasculature of a patient (e.g., patient 101 of FIG. 1) and be positionable proximate to a target tissue (e.g., within in a heart) region for diagnosis or treatment. Catheter 252 may include a proximal portion (not shown in the example of FIG. 2A) and a distal portion 256. In some examples, catheter 252 also may include one or more lumens disposed within catheter 252, which may provide mechanical, electrical, and / or fluid communication, e.g., saline irrigation, between the proximal portion of catheter 252 and the distal portion 256. The distal portion 256 may generally define the one or more treatment region(s) configured to monitor, diagnose, and / or treat a portion of a patient, as described above in relation to FIG. 1.

[0055] In some examples, catheter 252 includes an expandable structure 260 at distal portion 256 of catheter 252. In some examples, expandable structure 260 is configured to transition between a delivery (e.g., compressed) configuration and an expanded configuration. In the expanded configuration, expandable structure 260 can include a spherical lattice structure. In some examples, expandable structure 260 is configured to act as a therapy delivery element (e.g., an electrode), such as to deliver ablation therapy to target tissue (such as a portion of tissue 103 in the example of FIG. 1). In some examples, catheter 252 includes a distal ring electrode 261 A and a proximal ring electrode 261B.

[0056] In some examples, the expandable structure 260 includes a plurality of surface elements 262 (for example, nine surface elements 262, as shown in FIG. 2B) that are configured to act as sensors and / or therapy delivery elements. Surface elements 262 may be electrodes configured to deliver PF A. Surface elements 262 may additionally or alternatively be configured to deliver cryoablation.

[0057] In some examples, catheter 252 is configured for sensing signals, which may indicate patient parameters and / or system parameters. Processing circuitry (e.g., processing circuitry of interface unit 104 in the example of FIG. 1) may be configured to sense and / or record signals via surface elements 262 of catheter 252. Signals indicative of patient parameters and / or system parameters (e.g., temperature, tissue electrical activity, impedance, force, or the like) may be recorded by or between one or more of surface elements 262 in any suitable configuration.Recording may be via unipolar, bipolar, or other suitable configurations of surface elements 262. For example, recording may be between the distal electrode 261 A and one or more different electrodes, including one or more of proximal electrode 26 IB and / or distal ring electrode. Tissue electrical activity may also be recorded between one or more of electrodes 261 and a commonDocket No.: A0013501W001 / 1289-032W001 reference such as Wilson’s Central Terminal. In some examples, one or more of a power, a voltage and / or a current are measured between the proximal electrode 26 IB and distal electrode 261A.

[0058] In some examples, signals from one or more of surface elements 262, distal electrode 261 A and / or proximal electrode 261B provides information about an organ of a patient, including intracardiac signals. In some examples, intracardiac signals include cardiac EGMs, which may include bipolar and / or unipolar cardiac EGMs. Other intracardiac signals include monophasic action potentials. Signals from one or more of distal electrode 261 A and / or proximal electrode 26 IB, along with a voltage reference (e.g., a return electrode, not shown in the example of FIG.2B), may be used for determining impedance. As described above in relation to FIG. 1, interface unit 104 may be configured to receive signals via one or more electrodes 261 and / or surface elements 262. Based on the signals, interface unit may determine to activate / deactivate therapy delivery via one or more of surface elements 262.

[0059] FIG. 2B illustrates ablation catheter 272 that may be configured for ablation therapy, sensing, and / or mapping. Catheter 272 may be configured to pass through vasculature of a patient (e.g., patient 101 of FIG. 1) and be positionable proximate to a target tissue (e.g., within in a heart) region for diagnosis or treatment. Catheter 272 may include a proximal portion (not shown in the example of FIG. 2B) and a distal portion 274 In some examples, catheter 272 also may include one or more lumens disposed within catheter 272, which may provide mechanical, electrical, and / or fluid communication, e.g., saline irrigation, between the proximal portion of catheter 272 and the distal portion 274. The distal portion 274 may generally define the one or more treatment region(s) configured to monitor, diagnose, and / or treat a portion of a patient, as described above in relation to FIG. 1.

[0060] In some examples, catheter 272 includes an expandable structure 276 at distal portion 274 of catheter 272. In some examples, expandable structure 276 is configured to transition between a delivery (e.g., compressed) configuration and an expanded configuration. In the expanded configuration, expandable structure 276 can include a spherical lattice structure. In some examples, expandable structure 276 is configured to act as a therapy surface element (e.g., an electrode), such as to deliver ablation therapy to target tissue (such as a portion of tissue 103 in the example of FIG. 1). As shown in the example of FIG. 2B at least a portion of expandable structure 276 is mechanically coupled to a second elongated body 280. The second elongated body can be at least partially disposed within a first elongated body of catheter 272 disposed within elongated body 282, which may be a first elongated body. In some examples, relative axial movement of elongated body 112 and second elongated body 114 causes expandableDocket No.: A0013501W001 / 1289-032W001 structure to transform between the delivery (e.g., compressed) configuration and the deployed (e.g., radially expanded) configuration.

[0061] In some examples, expandable structure includes a plurality of therapy surface elements 278 (shown individually as surface element 278A, surface element 278B, surface element 278C, surface element 278D, surface element 278E, surface element 278F, surface element 278G, surface element 278H, surface element 2781 and collectively referred to herein as surface elements 278). Each of surface elements 278 may include an electrode (e.g., in the case of a RF or PFA catheter), a cryogenic element (e.g., in the case of a cryoablation catheter), an ultrasound transducer (e.g., in the case of an ultrasound catheter), or another suitable surface element. Throughout this disclosure, surface elements 278 are also be referred to as electrodes 278, although it is understood that surface elements 278 can include other surface elements besides electrodes. In some examples, surface elements 278 are disposed on, or carried by, an elongated body of catheter 272. While the example of FIG. 2B shows nine surface elements 278, any suitable number of surface elements 278 can be used (e.g., one, two, three, four, five, ten, twenty, etc.) in any suitable arrangement.

[0062] Surface elements 278 may operate in a similar fashion to surface elements 262 of FIG. 2A. Similar to catheter 252 FIG. 2A, catheter 272 may be configured for sensing signals, which may indicate patient parameters and / or system parameters. Processing circuitry (e.g., processing circuitry of interface unit 104 in the example of FIG. 1) may be configured to sense and / or record signals via surface elements 278 of catheter 272. Signals indicative of patient parameters and / or system parameters (e.g., temperature, tissue electrical activity, impedance, force, or the like) may be recorded by or between one or more of surface elements 272 in any suitable configuration. Recording may be via unipolar, bipolar, or other suitable configurations of surface elements 278.

[0063] Surface elements 278 may be of any suitable geometry and / or configuration. In examples, where surface elements 278 include one or more electrodes, geometries of electrodes include, but are not necessarily limited to, circular (e.g., ring) electrodes surrounding the body of catheter 272, conformable electrodes, cuff electrodes, segmented electrodes (e.g., electrodes disposed at different circumferential positions around catheter 272 instead of a continuous ring electrode), any combination thereof (e.g., ring electrodes and segmented electrodes).

[0064] In some examples, signals from one or more of surface elements 262 provide information about an organ of a patient, including intracardiac signals. In some examples, intracardiac signals include cardiac EGMs, which may include bipolar and / or unipolar cardiac EGMs. Other intracardiac signals include monophasic action potentials. Signals from one or more of distal electrode 261 A and / or proximal electrode 261B, along with a voltage referenceDocket No.: A0013501W001 / 1289-032W001 (e.g., a return electrode, not shown in the example of FIG. 2B), may be used for determining impedance. As described above in relation to FIG. 1, interface unit 104 may be configured to receive signals via one or more surface elements 278. In some examples, based on the signals, e.g., two or more of cardiac EGM, impedance, or tracked catheter location and / or tracked electrode location, interface unit 104 may determine to activate / deactivate delivery of therapy via one or more of surface elements 278.

[0065] FIG. 3 is a block diagram illustrating an example interface unit 300 and anatomical information device(s) 324 of an ablation system, in accordance with one or more aspects of this disclosure, in accordance with one or more aspects of this disclosure. Interface unit 300 of FIG. 3 may be an example of interface unit 104 of FIG. 1. As shown in FIG. 3, interface unit 300 may include an energy generator 302, processing circuitry 304, a user interface 305, a storage device 308, a positioning subsystem 316, telemetry circuitry 320, and sensing circuitry 322. Energy generator 302 may be configured to control therapy delivery elements (e.g., therapy delivery elements 110 of catheter 102) such as to provide electrical energy to electrodes (e.g., therapy delivery elements 110) to perform an ablation procedure to cardiac tissue or other tissues within the patient’s body, including but not limited to renal tissue, airway tissue, bones, organs, or tissue within the cardiac space or the pericardial space. For instance, energy generator 302 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 (PF A)” or “pulsed electric field ablation”) and / or pulsed radiofrequency ablation. In another example, energy generator 302 may be configured to control one or more cryogenic energy delivery elements to achieve desired cryogenic ablation. In some examples, energy generator includes multiple energy generators that are each capable of generating ablation signals in parallel. In some examples, interface unit 300 includes energy generators of different types, such as a pulsed field energy generator, a radiofrequency energy generator, and / or a cryogenic energy generator.

[0066] Processing circuitry 304 may be configured to control energy generator 302 to deliver ablation therapy according to one or more ablation parameters 318. Ablation parameters 318 may include a combination of energy delivery elements (e.g., a subset of therapy delivery elements 110) to the target tissue, a suggested positioning for one or more therapy delivery elements 110, a suggested energy level to be delivered, an energy modality (e.g., RF, cryogenic, PF A, etc.) or combination of modalities, or the like. In some examples, processing circuitry 304 is configured to, automatically and / or via user input, cause energy generator 302 to toggle between therapy delivery modalities (e.g., in examples where energy generator 302 is configured to delivery multiple different types of energy and / or therapy). In some examples, processing circuitry 304 isDocket No.: A0013501W001 / 1289-032W001 configured to, automatically and / or via user input, cause energy generator 302 deliver (e.g., simultaneously deliver) multiple energy and / or therapy modalities together.

[0067] Sensing circuitry 322 may be configured to sense, via one or more sensors 111 and / or therapy delivery elements 110, one or more of an impedance measurement or cardiac EGM to determine locations of therapy delivery elements 110 and / or catheter 112. For example, sensing circuitry 322 may measure a plurality of impedance values corresponding to each therapy delivery element of the plurality of therapy delivery elements 110. Based on relative values of impedances, processing circuitry 304 may determine whether the therapy delivery element is in contact with patient tissue, e.g., tissue 103. For example, impedance values measured by therapy delivery elements, e.g., electrodes, within a blood pool of patient 101 may be different from electrodes in contact with or nearly in contact with patient tissue 103. The relative impedance values may additionally be indicative of the location of each electrode relative to one or more sensitive structures of the heart of patient 101.

[0068] In some examples, processing circuitry 304 may, for example, determine (1) the difference between the maximum impedance magnitude at a low frequency, e.g., 12.5 Khz, for a given electrode and the absolute minimum impedance magnitude at the same low frequency across all electrodes for that ablation; (2) the difference between the maximum impedance magnitude at a high frequency, e.g., 100 kHz, for a given electrode and the absolute minimum impedance magnitude at the same high frequency across all electrodes for that ablation; and (3) the difference between the maximum impedance phase at a high frequency, e.g., 100 kHz, for a given electrode and the absolute minimum impedance phase at the same high frequency across all electrodes for that ablation. Processing circuitry 304 may assess contact based on relative values instead of absolute values. In some examples, processing circuitry 304 normalizes the impedance magnitude and phase data by the corresponding minimum value recorded during the procedure instead of normalizing the impedance magnitude and phase data by the corresponding maximum value. Since catheter 112 must be in blood at some point during the procedure and impedance values in blood are lower than impedance values in contact with tissue 103, the minimum impedance values correspond to when the catheter is in blood. The minimum impedance value may be affected by various blood characteristics, such as electrolyte, saline, and blood thinner levels. In some examples, an average minimum, in blood, impedance value is approximately 100.45 with a standard deviation of approximately 11.38, with a maximum value being approximately 126.6 and a minimum value being approximately 85.5. Processing circuitry 304 may determine the maximum impedance values by controlling sensing circuitry 322 to sample the impedance several times per second and may keep the maximum impedance value recorded over a one to two second window.Docket No.: A0013501W001 / 1289-032W001

[0069] To determine impedance values associated with electrodes positioned in the blood pool, while catheter 112 is in the blood pool of patient 101, e.g., in blood at a location near but not in contact with the target site, processing circuitry 304 determines impedance values. For each electrode, processing circuitry 304 may determine three impedance measurements at a first low frequency and a second high frequency. The low frequency may be in the range of approximately 5 kHz to approximately 25 kHz (for example, 12.5 kHz) and the high frequency may be in the range of approximately 80 kHz to approximately 140 kHz (for example, 100 kHz), with processing circuitry 304 measuring an impedance at the high frequency two times.Additionally, sensing circuitry 322 may take the impedance measurements at different frequencies sequentially or simultaneously. Impedance values recorded at 12.5 kHz may measure extracellular fluid resistance, whereas impedance values recorded at 100 kHz may measure resistance of intracellular fluid and membranes.

[0070] Processing circuitry 304 may determine and store a minimum magnitude value at the low frequency, a minimum magnitude value at the high frequency, and a minimum phase value at the high frequency. If a new minimum value is recorded for any of the values of interest, the new minimum value replaces the previous minimum value as the stored minimum value. Further, the minimum value may be a single discrete value or it may be the average or median of a plurality of minimum values in order to remove outlier values.

[0071] When catheter 112 is positioned such that the electrodes are in contact with tissue 103, sensing circuitry 322 measures three more impedance values in the same fashion as described above with respect to the three impedance measurements associated with the blood pool.

[0072] Processing circuitry 304 determines a first minimum impedance magnitude, which may be recorded at the low frequency across all the electrodes of catheter 112 and a second minimum impedance magnitude at the high frequency. Processing circuitry determines an impedance phase at the same high frequency a second time while catheter 112 is at least partially in contact with tissue 103.

[0073] Processing circuitry 304 compares each of the measurements associated with the blood pool to corresponding measurements associated with tissue 103. Based on the comparisons, processing circuitry 304 determines a range of impedance values associated with contact with tissue 103 and a range of impedance values associated with non-contact with tissue 103, i.e., contact with the blood pool. In some examples, the status of contact may include two groups, such as “normal contact” and “excessive contact.” Upon determining the ranges of impedance values associated with contact and non-contact, processing circuitry 304 may continuously or periodically determine whether each electrode is in contact or is not in contactDocket No.: A0013501W001 / 1289-032W001 with tissue 103 based on comparing impedance measurements to the ranges of impedance values associated with contact and non-contact.

[0074] Sensing circuitry 322 may additionally or alternatively sense a cardiac EGM of patient 101 via one or more sensors 111 and / or therapy delivery elements 110. Processing circuitry 304 determines locations of each of therapy delivery elements 110, e.g., electrodes, based on feature(s) of the cardiac EGM, such as a signal amplitude, one or more timing characteristics, frequency domain information, and / or a morphology feature. The cardiac EGM may include one or more of a unipolar cardiac EGM or a bipolar cardiac EGM. In some examples, an amplitude of the cardiac EGM may be indicative of proximity to tissue 103. For example, an electrode in contact with tissue 103 may sense a cardiac EGM with a relatively larger amplitude than an electrode in the blood pool. As another example, processing circuitry 304 may determine a location of an electrode relative to a sensitive structure based on the cardiac EGM. As an example, based on the location of the electrode, the timing characteristics of the cardiac EGM may be different. For example, a timing between an atrial signal and a ventricular signal may be different near the AV node than near other portions of the heart of patient 101. As another example, when sensors 111 and / or therapy delivery elements 110 are located near the AV node, the cardiac EGM may include His signals, e.g., signals recorded from the His bundle of a heart of patient 101. The His signals may be indicative of the location of each of therapy delivery elements 110, as well as changes to the surrounding tissue associated with therapy delivery.

[0075] In some examples, during the ablation procedure, the cardiac EGM of portions of tissue 103, e.g., ablated portions of tissue 103, may change. For example, healthy, non-ablated tissue may be associated with relatively clear and sharp cardiac EGM signals, e.g., cardiac EGM signals with high frequency components. Ablated and / or dead tissue may be associated with relatively long, fractionated EGM signals. In some examples, processing circuitry 304 may, based on information from location mapping associated with the tracked catheter and / or electrode location, determine specific portions of tissue 103 have been ablated. Processing circuitry 304 may confirm the ablation by checking for changes in the cardiac EGM, e.g., the unipolar cardiac EGM and / or bipolar cardiac EGM, associated with ablation, as described herein. In some examples, processing circuitry 304 may determine a location of the electrodes based on anticipated changes in the cardiac EGM associated with ablation of portions of tissue 103. For example, processing circuitry 304 may confirm the location of an electrode based on the electrodes sensing a cardiac EGM associated with at an anticipated location, e.g., at a portion of tissue 103 that processing circuitry 304 determined was ablated.Docket No.: A0013501W001 / 1289-032W001

[0076] In some examples, sensing circuitry 322 may additionally be configured to sense, via one or more temperature sensors, one or more temperature measurements associated with catheter 112 and / or with portions, e.g., sensors 111 and / or therapy delivery elements 110, of catheter 112. In some examples, processing circuitry 304 may determine whether sensors 111 and therapy delivery elements 110, e.g., electrodes, of catheter 112 are in contact with tissue 103 or primarily in contact with the blood pool. For example, processing circuitry 304 may compare a measured temperature to a temperature or range of temperatures associated with the patient blood pool and a temperature or range of temperatures associated with tissue 103. Based on the comparison, processing circuitry 304 determines whether the electrode is in contact with the patient blood pool or tissue 103. Additionally, PFA energy delivery during the ablation procedure may cause ablated patient tissue to increase in temperature. Therefore, after deliveries of PFA, some portions of tissue 103 will be warmer than other portions. Processing circuitry 304 may determine location information based on temperature. In some examples, processing circuitry 304 may confirm ablation of tissue 103 based on a change in temperature.

[0077] Processing circuitry 304 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 304 herein may be embodied as firmware, hardware, software or any combination thereof. Processing circuitry 304 controls energy generator 302 to generate signals according to various parameters (e.g., according to ablation parameters 318). In some examples, processing circuitry 304 may execute other instructions stored in storage device 308 to perform ablation based at least in part on anatomical information 310, which can be received from one or more anatomical information devices 324. Anatomical information devices 324 may be substantively similar to anatomical information device(s) 107 in the example of FIG. 1 and may be a part of catheter 112.

[0078] In some examples, anatomical information devices 324 includes a mapping system 326. Mapping system 326 includes location calculator 328 programmed to determine a location of a probe, e.g., a probe disposed on catheter 112, relative to patient anatomy based on location data and patient geometry information. Location data may include three-dimensional spatial coordinates of the probe carrying an emitter. The spatial coordinates can be provided in the coordinate system of the navigation system or have been registered with respect to the patient’s body 14. The geometry data can be generated (e.g., by geometry determining code - not shown) to spatially represent at least a region of the patient anatomy where the emitter is to apply energy.Docket No.: A0013501W001 / 1289-032W001

[0079] As an example, the geometry data can be anatomical geometry derived from imaging data acquired by a medical imaging modality, such as ultrasound, e.g., intracardiac echocardiography (ICE), transesophageal echocardiography (TEE), and / or transthoracic echocardiography (ECHO), single or multi-plane x-ray, CT, MRI, positron emission tomography (PET), fluoroscopy, single-photon emission computed tomography (SPECT), and the like. The locations of sensors 111, therapy delivery elements 110, and one or more surfaces of interest can be identified in a respective coordinate system of the acquired images (e.g., in the coordinate space of the body of patient 101) through appropriate image processing, including extraction and segmentation. For instance, segmented image data can be converted into a two-dimensional or three-dimensional graphical representation that includes the volume of interest for the patient. Appropriate anatomical or other landmarks, e.g., sensitive structures, can be identified in the geometry data to facilitate spatial registration of the location data and sensors. The identification of such landmarks can be done manually (e.g., by a person via image editing software) or automatically (e.g., via image processing techniques). In some examples, the imaging data, e.g., MRI imaging data with contrast and / or CT imaging data with contrast, may comprise preoperative imaging, which can be merged into an electroanatomical map. The imaging data may include indications of locations of sensitive structures such as the SA node, the AV node, phrenic nerves, etc.

[0080] Sensitive structures may include the AV node and / or the SA node. Sensitive structures may additionally or alternatively include nerves, such as a phrenic nerve and / or a vagus nerve, coronaries, the conduction system just beyond each of the SA node and the AV node, or collateral organs, such as the esophagus, the lungs, or bronchi.

[0081] Location calculator 328 can include a registration method programmed to spatially register the location data with the geometry data. For example, the registration method is programmed to transfer the location data and the geometry data into a common coordinate space (e.g., spatial domain), which can be the coordinate space of the location data, the geometry data or another common three-dimensional coordinate space. As a result, the location calculator 328 can provide the location (spatial coordinates) of the probe / emitter of catheter 112 in relative to patient anatomy described by the geometry data.

[0082] In some examples, mapping system 326 is configured to receive probe data, which may include a library of probe models for a plurality of different probes, which can include different configurations of a common type of probe or different types of probes (e.g., RF ablation electrodes, cryoballoons, PFA electrodes). For the example where the probe is implemented as RF and / or PFA electrodes, the available electrode models can include configurations ranging from a single electrode (corresponding to a single point) or an arrangement of electrodes (such asDocket No.: A0013501W001 / 1289-032W001 disposed along a straight or curved shaft) or three-dimensional electrode configurations (e.g., representing a volumetric arrangement of electrodes, such as on a basket, sphere or other 3D shape). Respective probe models can be generated for one or more manufactures’ product lines to facilitate selecting the correct configuration matching probe of catheter 112 that is being used.

[0083] In some examples, the mapping system 326 includes a target selector. The target selector can be programmed to define one or more target and / or non-target regions within the patient’s body. For example, one or more anatomical features to be avoided, e.g., sensitive structures, can be determined, such as by default set of rules or specified manually in response to a user selection. A target or non-target region can be an anatomical landmark or other identified region of tissue (e.g., AV node, SA node, phrenic nerves, pulmonary veins, and / or other structures) considered susceptible or sensitive to damage during such treatment.

[0084] As a further example, when the probe includes PFA electrodes, the energy field can be representative of an electrical field. In such example, the shape of the electric field and relative penetration depth of current densities can be programmed into the probe model over a set of operating parameters. For example, if the shape of the electric field and relative penetration depth of current densities into tissue are strong enough the field could damage non-target tissue (e.g., nerve tissue). Interface unit 300 may receive information from anatomical information devices 324 indicative of locations of target and non-target regions / sensitive structures and may programmed to suggest or specify one or more operating parameters to avoid potential damage to non-target regions, such as by identifying one or more operating parameters (e.g., which electrodes should be active). Interface unit 300 may automatically adjust one or more operating parameters of the probe of catheter 112 to prevent (e.g., reduce, limit, or stop) potential damage to sensitive structures.

[0085] In some examples, location calculator 328 additionally determines the location of catheter 112, therapy delivery elements 110 and / or sensors 111 based on data from an imaging modality, such as intracardiac echocardiography (ICE), a transthoracic echocardiogram (ECHO), a transesophageal echocardiogram (TEE), fluoroscopy, or X-ray, e.g., angiography. In some examples, based on the ICE, ECHO, TEE, fluoroscopy, or X-ray information, the location data, and the patient geometry data, location calculator 328 determines the location of therapy delivery elements 110 and / or sensors 111. In some examples, based on the ICE, ECHO, TEE, fluoroscopy, or X-ray information, user interface 305 may generate a visualization of the location(s) of sensitive structure(s). In some examples, based on the ICE, ECHO, TEE, fluoroscopy, or X-ray information, processing circuitry 304 determines a distance between the sensitive structure(s) and catheter 112 and / or therapy delivery elements 110. In some examples,Docket No.: A0013501W001 / 1289-032W001 processing circuitry 304 may additionally determine location(s) of sensitive structure(s) based on relative patient anatomy from historical cases.

[0086] Storage device 308 may be configured to store information received by interface unit 300, e.g., from anatomical information devices 324 and / or catheter 112. Storage device 308 may include a computer-readable storage medium or computer-readable storage device. In some examples, storage device 308 includes one or more of a short-term memory or a long-term memory. Storage device 308 may include, for example, random-access memories (RAM), dynamic random-access memories (DRAM), static random-access memories (SRAM), ferroelectric random-access memories (FRAM), 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 308 is used to store data indicative of instructions, e.g., for execution by processing circuitry 304, respectively. Storage device 308 may be configured to store anatomical information 310, ablation parameters 318, as well as other suitable information.

[0087] Anatomical information 310 may be patient specific anatomical information, typical patients’ anatomies, and / or a combination of the two, enabling augmentation of the patient specific anatomical information. For example, one patient may have a different anatomy than another patient. Anatomical information 310 may be generated by a computed tomography (CT) device, a magnetic resonance imaging (MRI) device, an ultrasound (U / S) device, or from electrical characterization, such as from a pacing device, an electrophysiology (EP) mapping device, and / or a non-invasive mapping device (which may be examples of anatomical information device(s) 324). In some examples, anatomical information includes a model of an organ (e.g., a heart). In some examples, the model includes a “shell” representing the boundary of an organ (e.g., the heart). The model may additionally include sensitive structures of the patient, e.g., the SA node and the AV node.

[0088] User interface 305 may be an example of user interface 105 as discussed in the example of FIG. 1. Interface unit 300 may be configured to generate and present, via user interface 305, representations of medical devices (e.g., catheter 102, therapy delivery elements 110, and / or sensors 111 as described in connection with FIG. 1), such as in relation to tissue of patient 101. User interface 305 may display which therapy delivery elements of therapy delivery elements 110 are deactivated and which are activated. In some examples, interface unit 300 may automatically activate / deactivate therapy delivery elements 110. In some examples, user interface 305 may generate for display a recommendation to the user to deactivate one or more elements of therapy delivery elements 110 for user review.Docket No.: A0013501W001 / 1289-032W001

[0089] Telemetry circuitry 320 may include any suitable hardware, firmware, software or any combination thereof for communicating with another device, such as anatomical information device(s) 107. Telemetry circuitry 320 may be configured to communicate using any of a variety of wireless communication schemes, such as Bluetooth® or Bluetooth Low Energy®, WiFi, 4G, or 5G, or a wired communication scheme such as ethernet. Under the control of processing circuitry 304, telemetry circuitry 320 may receive downlink telemetry from, and / or send uplink telemetry to, external devices, with the aid of an internal or external antenna, or via wires.

[0090] In some examples, interface unit 300 includes a positioning subsystem 316 configured to track and record positions of a catheter or components of a catheter, such as catheter 102 as discussed in the example of FIG. 1. For example, as discussed in relation to the components of catheter 102 in the example of FIG. 1, positioning subsystem 316 may track a position of one or more of catheter 102, therapy delivery elements 110, and / or sensors 111. In some examples, the positioning subsystem 316 is configured to track one or more of catheter 102, therapy delivery elements 110, and / or sensors 111 via two or more of a tracked catheter location and / or a tracked electrode location, an impedance measurement, or a cardiac EGM.

[0091] FIG. 4 is a flowchart illustrating an example operation for deactivating electrodes of a PFA catheter based on a location of the electrodes, in accordance with one or more techniques of the disclosure. Although the example operation of FIG. 4 is described with respect to a PFA catheter, the techniques of this disclosure are not so limited. For example, the catheter of the example operation of FIG. 4 may additionally or alternatively comprise a cryoablation catheter.

[0092] For each therapy delivery element, e.g., electrode, of a plurality of electrodes of a PFA catheter, processing circuitry, e.g., processing circuitry 304 of interface unit 300, determines a location of the electrode based on two or more of an impedance measurement, a sensed cardiac signal, e.g., a cardiac EGM, or a tracked catheter location and / or a tracked electrode location (402). The location of the electrode may be a location of the electrode relative to one or more of patient tissue, one or more sensitive structures, or a blood pool of the patient. In some examples, the location of the electrode may be a location of the electrode relative to patient tissue and one or more sensitive structures of the patient. In some examples, the location of the electrode may be a location of the electrode relative to one or more sensitive structures and the blood pool of the patient.

[0093] In some examples, processing circuitry 304 weighs each of the two or more of the impedance measurement, the cardiac EGM, and the tracked catheter location and / or the tracked electrode location equally. In some examples, processing circuitry 304 assigns different weights to each of the impedance measurement, the cardiac EGM, and the tracked catheter location and / or the tracked electrode location. As an example, processing circuitry 304 may assign aDocket No.: A0013501W001 / 1289-032W001 larger weight to the impedance measurement than the cardiac EGM. In some examples, processing circuitry 304 assigns dynamic weights to each of the impedance measurement, the cardiac EGM, and the tracked catheter location and / or the tracked electrode location. As an example, processing circuitry 304 may initially assign the cardiac EGM a first weight that is relatively high compared to a second weight. In some examples, ablation, e.g., PF A, causes irreversible electroporation to patient tissue, which can lead to changes in the cardiac EGM. These changes may increase complexity of analyzing the cardiac EGM signal, and, in some examples, may render the cardiac EGM a less accurate indicator of the location of the electrode with respect to patient tissue. In some examples, during an ablation procedure, processing circuitry 304 may switch from using a first two or more of impedance, cardiac EGM, or tracked catheter location and / or tracked electrode location to using a second one or more of impedance, cardiac EGM, or tracked catheter location and / or the tracked electrode location. As an example, processing circuitry 304 may initially determine location based on tracked catheter location and / or the tracked electrode location and cardiac EGM and may switch to location mapping and impedance. As another example, processing circuitry 304 may initially determine location based on each of tracked catheter location and / or tracked electrode location, cardiac EGM, and impedance and may switch to determining the location based on cardiac EGM and impedance. In some examples, processing circuitry 304 may additionally determine the location based on a temperature measurement.

[0094] In some examples, processing circuitry 304 assigns different weights to the two or more of the impedance measurement, the cardiac EGM, or the tracked catheter location and / or the tracked electrode location for determining the location of the electrode relative to sensitive structure(s) and for determining whether the electrode is in contact with patient tissue and / or whether the electrode is primarily in contact with the blood pool. As an example, to determine the location of the electrode relative to sensitive structure(s), processing circuitry 304 may assign a highest weight value to tracked catheter location and / or the tracked electrode location and may assign lower weight values to the impedance measurement and / or the cardiac EGM. To determine whether the electrode is in contact with patient tissue and / or whether the electrode is primarily in contact with the blood pool, processing circuitry 304 may assign a lowest weight value to the tracked catheter location and / or the tracked electrode location and may assign higher weigh values to the impedance measurement and / or the cardiac EGM.

[0095] In some examples, processing circuitry 304 determines location and / or contact based on each of the impedance measurement, the cardiac EGM, and the tracked catheter location and / or the tracked electrode location. If all three of the impedance measurement, the cardiac EGM, and the tracked catheter location and / or the tracked electrode location are indicative ofDocket No.: A0013501W001 / 1289-032W001 contact with patient tissue, processing circuitry 304 may determine the electrode is in contact with patient tissue with a relatively high confidence. If two of the impedance measurement, the cardiac EGM, and the tracked catheter location and / or the tracked electrode location are indicative of contact with patient tissue and the remaining one of the impedance measurement, the cardiac EGM, and the tracked catheter location and / or the tracked electrode location is indicative of no contact, processing circuitry 304 may determine the electrode is in contact with patient tissue with a relatively low confidence. If only one of the impedance measurement, the cardiac EGM, or the tracked catheter location and / or the tracked electrode location is indicative of contact, processing circuitry 304 may determine the electrode is not in contact with the patient tissue.

[0096] For each electrode of the plurality of electrodes and based on a determination that the location of the electrode is not in contact with patient tissue, that the location of the electrode is primarily in the blood pool, e.g., primarily in contact with the blood pool, or that the location of the electrode is within a threshold distance from one or more sensitive structures, processing circuitry 304 determines to deactivate delivery of PFA energy via the electrode (404). Processing circuitry 304 determines to deactivate the electrode when the electrode is not in contact with patient tissue, e.g., when the electrode is primarily in the blood pool of patient 101.

[0097] Processing circuitry 304 may determine the electrode is primarily in contact with the blood pool of patient 101 when ablative energy delivered via the electrode would provide limited ablative energy to patient tissue and would primarily ablate the blood pool. In some examples, the electrode is primarily in contact with the blood pool of patient 101 when a threshold amount of ablative energy delivered via the electrode would ablate the blood pool. In some examples, the electrode is primarily in contact with the blood pool of patient 101 when a threshold amount of the electrode is in contact with the blood pool and not with patient tissue. In one example, if the electrode is partially, e.g., less than 50%, in contact with patient tissue and the remaining portion of the electrode, e.g., more than 50% of the electrode, is in contact with the blood pool, processing circuitry may determine the electrode is primarily in contact with the blood pool. As an example, if the electrode is partially, e.g., 25%, in contact with patient tissue and the remaining portion, e.g., 75%, of the electrode is in contact with the blood pool, processing circuitry 304 may determine the electrode is in contact with the blood pool.

[0098] In some examples, the threshold amount of electrode in contact with the blood pool and not with patient tissue to determine the electrode is primarily in contact with the blood pool may vary in different situations. As an example, the threshold amount may be different for different ablation systems. For example, based on the surface area of electrodes of ablation systems, in ablation systems with relatively large electrodes, the threshold amount may beDocket No.: A0013501W001 / 1289-032W001 relatively high. In ablation systems with relatively small electrodes, the threshold amount may be relatively low. As another example, the threshold amount may be different based on a risk of collateral damage, e.g., hemolysis, associated with the ablation therapy. The threshold amount may vary from 25% to 75% in some examples. For example, the threshold amount may be 25% when the risk of collateral damage is relatively high and may be 75% when the risk for collateral damage is relatively low.

[0099] In some examples, the threshold amount of electrode in contact with the blood pool and not with patient tissue that corresponds to processing circuitry 304 determining the electrode is primarily in contact with the blood pool may change over time. For example, over time processing circuitry 304 may decrease the threshold amount of the electrode in contact with the blood pool and not with patient tissue. For example, at a first time, processing circuitry 304 may set the threshold to 50%, and at a second time, processing circuitry 304 may set the threshold to 25%. In such an example, at the first time, processing circuitry 304 may determine that an electrode 50% in contact with the blood pool and 50% in contact with patient tissue is not in contact with the blood pool. At the second time, processing circuitry 304 may determine that the electrode 50% in contact with the blood pool is in contact with the blood pool.

[0100] Processing circuitry 304 additionally determines to deactivate the electrode when the electrode is within a threshold distance from one or more sensitive structures, e.g., the AV node or the SA node. In other words, if the electrode is not in contact with patient tissue or if the electrode is within the threshold distance, e.g., 0.5 millimeters, from one or more sensitive structures, processing circuitry 304 deactivates the electrode. Processing circuitry 304 delivers PF A energy via electrodes of the plurality of electrodes through which delivery of PF A has not been deactivated (406). In some examples, the threshold distance may vary based on one or more of a geometry of catheter 112 or one or more energy settings associated with the delivery of PF A. For example, when the energy settings are relatively low, the threshold distance may be longer than when the energy settings are relatively high.

[0101] In some examples, processing circuitry 304 may deactivate all the electrodes or all but one of the electrodes of catheter 112. In some examples, processing circuitry 304 may control user interface 305 to display electrode deactivation information to the user. In some examples, if a threshold number of electrodes have been deactivated, user interface 305 may output a suggestion to adjust a position of catheter 112. In some examples, the user may determine to adjust a position of catheter 112 based on the displayed electrode deactivation information and / or the suggestion. In some examples, processing circuitry 304 may determine to deactivate all the electrodes if less than a threshold number, e.g., 2 electrodes, remain activated. The user may adjust a position of catheter 112 until processing circuitry 304 activates 2 or more electrodes.Docket No.: A0013501W001 / 1289-032W001

[0102] Processing circuitry 304 may perform the example operation of FIG. 4 a plurality of times during an ablation procedure. As an example, each time the user adjusts a position of catheter 112, processing circuitry 304 may perform the example operation of FIG. 4. As another example, processing circuitry 304 may continuously perform the example operation of FIG. 4. In some examples, processing circuitry 304 performs the example operation at the beginning of the ablation procedure. In some examples, processing circuitry 304 performs the example operation during the ablation procedure and in response to one or more criteria being met and / or in response to a stimulus.

[0103] FIG. 5 is a flowchart illustrating an example operation for activating electrodes of a PFA catheter based on a location of the electrodes, in accordance with one or more techniques of the disclosure. Although the example operation of FIG. 5 is described with respect to a PFA catheter, the techniques of this disclosure are not so limited. For example, the catheter of the example operation of FIG. 5 may additionally or alternatively comprise a cryoablation catheter.

[0104] For each therapy delivery element, e.g., electrode, of a plurality of therapy delivery elements, e.g., therapy delivery elements 110, on a catheter, e.g., a PFA catheter, processing circuitry, e.g., processing circuitry 304 of interface unit 300, determines a location of the electrode based on two or more of an impedance measurement, a sensed cardiac signal, e.g., a cardiac EGM, or a tracked catheter location and / or a tracked electrode location (502). Processing circuitry 304 may determine the location of the electrode based on the two or more of the impedance measurement, the cardiac EGM, or the tracked catheter location and / or the tracked electrode location according to the examples described with respect to the example operation of FIG. 4. In some examples, processing circuitry 304 may additionally determine the location based on a temperature measurement.

[0105] The location of the electrode may be a location of the electrode relative to one or more of patient tissue, one or more sensitive structures, or a blood pool of the patient. In some examples, the location of the electrode may be a location of the electrode relative to patient tissue and one or more sensitive structures of the patient. In some examples, the location of the electrode may be a location of the electrode relative to one or more sensitive structures and the blood pool of the patient.

[0106] Based on the determination of the location of the electrode, processing circuitry 304 determines whether to activate delivery of therapy via the electrode, e.g., activate the electrode. For each electrode of the plurality of electrodes, based on a determination that the location of the electrode is in contact with patient tissue and that the location of the electrode meets a minimum threshold distance from one or more sensitive structures, processing circuitry 304 determines to activate delivery of PFA energy via the electrode (504). Processing circuitry 304 determines toDocket No.: A0013501W001 / 1289-032W001 activate the electrode when the electrode is in contact with patient tissue and when the location of the electrode meets a minimum threshold distance from one or more sensitive structures, e.g., the AV node or the SA node. In some examples, if processing circuitry 304 determines the electrode is not in contact with patient tissue, processing circuitry 304 does not activate the electrode. For example, the electrode may be located within the blood pool of patient 101. In some examples, activating the electrode comprises supplying energy to the electrode.

[0107] Processing circuitry 304 delivers ablation therapy, e.g., PF A, via electrodes of the plurality of electrodes through which delivery of PFA energy has been activated (506).Processing circuitry 304 may perform the example operation of FIG. 5 a plurality of times during an ablation procedure. As an example, each time the user adjusts a position of catheter 112, processing circuitry 304 may perform the example operation of FIG. 5. As another example, processing circuitry 304 may continuously perform the example operation of FIG. 5. In some examples, processing circuitry 304 performs the example operation at the beginning of the ablation procedure. In some examples, processing circuitry 304 performs the example operation during the ablation procedure and in response to one or more criteria being met and / or in response to a stimulus.

[0108] FIG. 6 is a flowchart illustrating an example operation for determining which electrodes to deactivate based on location in response to a hemolysis risk level meeting a threshold, in accordance with one or more techniques of the disclosure. Although the example operation of FIG. 6 is described with respect to a PFA catheter, the techniques of this disclosure are not so limited. For example, the catheter of the example operation of FIG. 6 may additionally or alternatively comprise a cryoablation catheter. The example operation of FIG. 6 may be a specific example of the example operation of FIG. 4.

[0109] Processing circuitry 304 controls energy generator 302 to deliver ablation energy, e.g., PFA energy, via the plurality of therapy delivery elements of a catheter, e.g., therapy delivery elements 110 of catheter 112 (602). In some examples, catheter 112 comprises a PFA catheter, and the plurality of therapy delivery elements comprise electrodes. Processing circuitry 304 compares a hemolysis risk level to a threshold (604).

[0110] For each electrode, processing circuitry 304 determines a location of each electrode based on two or more of an impedance measurement, a sensed cardiac signal, e.g., a cardiac EGM, or tracked catheter location and / or tracked electrode location (606). The location of the electrode may be a location of the electrode relative to one or more of patient tissue, one or more sensitive structures, or a blood pool of the patient. In some examples, the location of the electrode may be a location of the electrode relative to patient tissue and one or more sensitiveDocket No.: A0013501W001 / 1289-032W001 structures of the patient. In some examples, the location of the electrode may be a location of the electrode relative to one or more sensitive structures and the blood pool of the patient.[OHl] In some examples, processing circuitry 304 determines the location of the electrode in response to the hemolysis risk level meeting a threshold. In some examples, processing circuitry 304 initially determines the location based on one of the impedance measurement, the cardiac EGM, or the tracked catheter location and / or the tracked electrode location based on the location mapping. In response to the hemolysis risk level meeting the threshold, processing circuitry 304 switches to determine the location based on the two or more of the impedance measurement, the cardiac EGM, or the tracked catheter location and / or the tracked electrode location. For example, processing circuitry 304 may initially determine the electrode location based only on the tracked catheter location and / or the tracked electrode location, and in response to the hemolysis risk level meeting the threshold, processing circuitry may switch to determining the location based on the tracked catheter location and / or the tracked electrode location, the impedance measurement, and the cardiac EGM. In some examples, processing circuitry 304 determines the location of the electrode independent of the hemolysis risk level meeting the threshold.

[0112] Based on the determined location of the electrode and the determination that the hemolysis risk level meets the threshold, processing circuitry 304 determines whether to deactivate delivery of therapy via the electrode, e.g., deactivate the electrode. For each electrode of the plurality of electrodes, based on the hemolysis risk level meeting the threshold and based on a determination of one or more of that the location of the electrode is not in contact with patient tissue, that the location of the electrode is primarily in contact with the blood pool, or that the location of the electrode is within a threshold distance from one or more sensitive structures, processing circuitry 302 determines to deactivate delivery of PFA energy via the electrode (608). Processing circuitry 304 determines to deactivate the electrode when one or more of the location of the electrode is not in contact with patient tissue or when the location of the electrode is within a threshold distance from one or more sensitive structures.

[0113] Processing circuitry 304 controls energy generator 302 to deliver PFA energy via electrodes of the plurality of electrodes through which delivery of PFA energy has not been deactivated (610). In some examples, processing circuitry 304 may continuously determine whether to deactivate each electrode of the plurality of electrodes in response to the hemolysis risk level meeting the threshold. In some examples, processing circuitry may determine whether to deactivate each electrode of the plurality of electrodes in response to the hemolysis risk level meeting the threshold each time the user adjusts a location of catheter 112.

[0114] In some examples, instead of determining, for each electrode of the plurality of electrodes, whether to deactivate the electrode, processing circuitry 304 may, based on theDocket No.: A0013501W001 / 1289-032W001 determination of the location of the electrode and based on the determination that the hemolysis risk level meets the threshold, determine whether to activate the electrode, e.g., determine whether to continue to control energy generator 302 to deliver energy via the electrode.

[0115] FIG. 7 is a flowchart illustrating an example operation for determining a risk of hemolysis based on a number of applications of PF A energy, in accordance with one or more techniques of the disclosure. In some examples, the example operation of FIG. 7 may be a specific example of step 604 of the example operation of FIG. 6.

[0116] Processing circuitry 304 determines a number of PFA pulses that energy generator 302 has applied to patient 101, e.g., tissue 103 of patient 101, via the plurality of electrodes (702). Processing circuitry 304 compares the number of pulses to a threshold number of pulses, e.g., 50 pulses or 100 pulses. In some examples, the threshold number of pulses is specific to a configuration of the catheter, e.g., a volume of the catheter, a shape of the catheter, and / or a number of electrodes on the catheter (704). The threshold number of pulses may also be specific to one or more parameters of the PFA pulses, e.g., one or more parameters of the waveform(s) of the PFA pulses. In some examples, each PFA pulse may be associated with some amount of hemolysis, e.g., the breakdown of red blood cells. In some examples, relatively small amounts of hemolysis may not lead to notable negative outcomes for patient 101. As examples, an increased amount of hemolysis can lead to anemia, jaundice, renal dysfunction. By providing more targeted PFA therapy using a subset of the available electrodes during an ablation procedure, the techniques of this disclosure may prevent (e.g., reduce, limit, or stop) adverse patient outcomes associated with hemolysis.

[0117] If the number of PFA pulses exceeds the threshold, processing circuitry 304 may determine to determine, for each electrode of the plurality of electrodes, whether to deactivate delivery of therapy via the electrode, e.g., deactivate the electrode. If the number of PFA pulses falls below the threshold, processing circuitry 304 may not begin determining, for each electrode of the plurality of electrodes, whether to deactivate the electrode.

[0118] In some examples, in addition to or alternatively to comparing the number of pulses to the threshold number of pulses, processing circuitry 304 may determine a volume of blood exposed to the number PFA pulses and the electric field intensity associated with the number of PFA pulses. Processing circuitry 304 may determine a hemolysis metric based on the volume of blood exposed and the electric field intensity associated with the number of PFA pulses.Processing circuitry 304 may compare the hemolysis metric to a hemolysis threshold. If the hemolysis metric exceeds the hemolysis threshold, processing circuitry 304 may begin determining, for each electrode of the plurality of electrodes, whether to deactivate the electrode. If the hemolysis metric falls below the hemolysis threshold, processing circuitry 304 may notDocket No.: A0013501W001 / 1289-032W001 begin determining, for each electrode of the plurality of electrodes, whether to deactivate the electrode.

[0119] In some examples, system 100 may initially provide PF A therapy with all of the electrodes of the plurality of electrodes to increase an efficiency of the PFA procedure and / or to conserve energy associated with determining location of the electrodes using the two or more of the impedance measurement, the cardiac EGM, or the tracked catheter location and / or the tracked electrode location. As discussed below in FIG. 11, a difference between an amount of hemolysis associated with electrodes that are not in contact with patient tissue and an amount of hemolysis associated with electrodes that are in contact with patient tissue during ablation may increase as the number of applications of PFA increases. Therefore, it may be more important, e.g., more impactful, to deactivate electrodes in the blood pool later in an ablation procedure.

[0120] FIG. 8 is a flowchart illustrating an example operation for determining which electrodes to deactivate based on electrode location in response to a location of the PFA catheter being which a threshold distance from a sensitive structure, in accordance with one or more techniques of the disclosure. Although the example operation of FIG. 8 is described with respect to a PFA catheter, the techniques of this disclosure may be implemented in any catheter configured for ablation, such as a cryoablation catheter. The example operation FIG. 8 may be a specific example of the example operation of FIG. 4.

[0121] Processing circuitry 304 controls energy generator 302 to deliver PFA energy via a plurality of therapy delivery elements, e.g., electrodes, of the PFA catheter (802). Processing circuitry 304 determines the location of the PFA catheter relative to a sensitive structure, e.g., the AV node and / or the SA node (804). Processing circuitry 304 may determine the location of the PFA catheter based on one or more of a tracked catheter and / or electrode location associated with location mapping, an impedance measurement, or a cardiac EGM. Processing circuitry 304 determines a location of each electrode of the plurality of electrodes based on two or more of the impedance measurement, the sensed cardiac signal, e.g., a cardiac EGM, or the tracked catheter location and / or the tracked electrode location (806). In some examples, processing circuitry 304 determines the location of each electrode in response to the location of the PFA catheter being within a threshold distance from a sensitive structure.

[0122] The location of the electrode may be a location of the electrode relative to one or more of patient tissue, one or more sensitive structures, or a blood pool of the patient. In some examples, the location of the electrode may be a location of the electrode relative to patient tissue and one or more sensitive structures of the patient. In some examples, the location of the electrode may be a location of the electrode relative to one or more sensitive structures and the blood pool of the patient.Docket No.: A0013501W001 / 1289-032W001

[0123] For each electrode, based on the determination that the PFA catheter is within the threshold distance from the sensitive structure and based on the location of the electrode, processing circuitry 304 determines whether to deactivate therapy delivery via the electrode, e.g., deactivate the electrode. Based on the determination that the PFA catheter is within the threshold distance from the one or more sensitive structures and based on a determination of one or more of that the location of the electrode is not in contact with patient tissue, that the location of the electrode is primarily in contact with the blood pool, or that the location of the electrode is within a threshold distance from the one or more sensitive structures, processing circuitry 304 determines to deactivate delivery of PFA energy via the electrode (808). Processing circuitry 304 determines to deactivate the electrode when the electrode is one or more of not in contact with patient tissue, e.g., patient tissue 103, or when the location of the electrode is within a threshold distance from the sensitive structure. In some examples, the threshold distance may include a threshold distance for the PFA catheter and a threshold distance for the electrode. As an example, the threshold distance for the electrode may be between 0.5 millimeters and 5 millimeters. The threshold distance may vary based on energy settings for energy generation circuitry 302 and / or a configuration of catheter 112. Processing circuitry controls energy generation circuitry 302 to deliver PFA energy via electrodes of the plurality of electrodes through which delivery of PFA energy has not been deactivated (810).

[0124] In some examples, instead of determining, for each electrode of the plurality of electrodes, whether to deactivate the electrode, processing circuitry 304 may, based on the determination of the location of the electrode and based on the determination that the location PFA catheter is within the threshold distance from the sensitive structure, determine whether to activate the electrode, e.g., determine whether to continue to control energy generator 302 to deliver energy via the electrode.

[0125] FIG. 9 is a flowchart illustrating an example operation for determining whether to deactivate an electrode based on the location of the electrode relative to one or more of patient tissue, a patient blood pool, or one or more sensitive structures, in accordance with one or more techniques of the disclosure.

[0126] Although described with respect to electrodes of a PFA catheter, the example operation of FIG. 9 may also be implemented with respect to therapy delivery elements of a cryoablation catheter or with any other therapy delivery element, e.g., a cryo-refrigerant jet, of a catheter configured for ablation therapy.

[0127] Processing circuitry 304 determines whether each electrode of a plurality of electrodes of a PFA catheter are in contact with patient tissue, e.g., tissue 103, or with a blood pool of patient 101 (902). Processing circuitry 304 determines whether each electrode of theDocket No.: A0013501W001 / 1289-032W001 plurality of electrodes are in contact with patient tissue or with the blood pool based on two or more of a tracked catheter location and / or a tracked electrode location associated with location mapping, an impedance measurement, or a cardiac EGM. In some examples, processing circuitry 304 may determine “contact” when the electrode is in physical contact with or is within a threshold distance of patient tissue. Processing circuitry 304 may determine “no contact” when the electrode is more than the threshold distance away from patient tissue.

[0128] Processing circuitry 304 additionally determines the location of the electrode relative to one or more sensitive structures, e.g., the AV node (904). Processing circuitry 304 determines the location of the electrode relative to the one or more sensitive structures based on two or more of a tracked catheter location and / or a tracked electrode location associated with location mapping, an impedance measurement, or a cardiac EGM (904).

[0129] Based on the determinations of whether the electrode is in contact with the patient tissue or with the blood pool and the location of the electrode relative to the one or more sensitive structures, processing circuitry 304 determines whether to deactivate the electrode, e.g., whether to not supply power to the electrode or whether to stop supplying power to the electrode (906). In some examples, instead of determining, for each electrode of the plurality of electrodes, whether to deactivate the electrode, processing circuitry 304 may, based on the determinations, determine whether to activate the electrode, e.g., determine whether to continue to control energy generator 302 to deliver energy via the electrode.

[0130] FIG. 10 is a flowchart illustrating an example operation for updating an activation state of an electrode based on an updated electrode location, in accordance with one or more techniques of the disclosure. Although described with respect to electrodes, the techniques of this disclosure may be implemented with respect to any therapy delivery elements of a catheter for an ablation procedure.

[0131] In some examples, the techniques of the example operation occur subsequent to the example operations described with respect to any of FIGS. 4, 5, 6, or 8. Processing circuitry 304 determines an updated location for each electrode of the plurality of electrodes of catheter 112 (1002). The updated location is a location of the electrode relative to one or more of patient tissue, a patient blood pool, or one or more sensitive structures of the patient. In some examples, processing circuitry 304 determines the updated location in response to the user adjusting a position of catheter 112. In some examples, processing circuitry 304 may confirm and / or determine the updated location based on anticipated changes in the tracked electrode and / or catheter location associated with the location mapping, the impedance measurement, or the cardiac EGM signal due to ablation. For example, system 100 may ablate a first portion of tissue 103 and may not ablate a second portion of tissue 103 while catheter 112 is in a first position.Docket No.: A0013501W001 / 1289-032W001 When catheter 112 moves to a second position, the location of each electrode with respect to the ablated first portion of tissue 103 and the second non-ablated portion of tissue 103 shifts.Processing circuitry 304 may leverage changes in, for example, the cardiac EGM for the ablated first portion of tissue 103, to determine / confirm the updated location. For example, upon ablation, the cardiac EGM may become less defined and / or more fractionated and an amplitude of the cardiac EGM may decrease relative to a cardiac EGM sensed before the ablation.Processing circuitry 304 may anticipate these changes in cardiac EGM and may confirm the updated locations of each of the electrodes based on determining these anticipated changes in the cardiac EGM.

[0132] In examples in which system 100 is additionally configured to determine the location of each of the plurality of electrodes based on a temperature measurement, processing circuitry 304 may additionally determine / confirm electrode location based on anticipated temperature changes. As an example, upon delivering PFA pulses to portions of tissue 103, the first ablated portion may be warmer than the second non-ablated portion.

[0133] Based on the updated location, processing circuitry 304 determines whether to switch an activation state of the electrode (1004). For example, processing circuitry 304 determines whether to switch an activated electrode to a deactivated electrode state or whether to switch a deactivated electrode to an activated electrode state. Processing circuitry 304 may control energy generator 302 to deliver energy via the electrodes in the activated state.

[0134] FIG. 11 is a is a graphical representation of an amount of plasma free hemoglobin relative to a number of applications of PFA energy when electrodes are in contact with patient tissue and when electrodes are not in contact with patient tissue, in accordance with one or more techniques of this disclosure.

[0135] Plasma free hemoglobin is hemoglobin found outside of red blood cells in the plasma. Hemoglobin is typically confined within red blood cells. When ablation energy, e.g., PFA energy, is delivered to the blood pool, each application ablation energy can cause hemolysis, e.g., the breakdown of red blood cells, resulting in plasma free hemoglobin. Therefore, the extent of hemolysis is proportional to the amount of plasma free hemoglobin in the plasma of a patient. When electrodes are located in the blood pool and are not in contact with patient tissue, the ablation energy causes more hemolysis than when electrodes are in contact with patient tissue. FIG. 11 includes a graphical representation of an amount of hemolysis associated with applications of PFA energy.

[0136] Line 1102 corresponds to an amount of plasma free hemoglobin resulting from PFA energy applications by electrodes of a PFA catheter that were not in contact with patient tissue, e.g., electrodes that were primarily in contact with the blood pool during applications of the PFADocket No.: A0013501W001 / 1289-032W001 energy. Line 1104 corresponds to an amount of plasma free hemoglobin resulting from PFA energy applications by electrodes of a PFA catheter that were in contact with patient tissue, e.g., electrodes that were not primarily in contact with the blood pool during applications of the PFA energy.

[0137] The amount of plasma free hemoglobin associated with line 1102 is higher than the amount of plasma free hemoglobin associated with line 1104 for all numbers of applications. The difference between the amount of plasma free hemoglobin associated with line 1102 and line 1104 increases with increasing numbers of applications. Therefore, it may be more important to prevent (e.g., reduce, limit, or stop) delivery of energy via electrodes located primarily in the blood pool later in an ablation procedure than early in an ablation procedure when the amount of hemolysis is relatively similar. In some examples, by beginning to determine a location of each electrode of the plurality of electrodes on the PFA catheter based on the two or more of the a tracked catheter location and / or a tracked electrode location associated with the location mapping, the impedance measurement, or the cardiac EGM after a threshold number of applications of PFA energy, as described in the example operation of FIG. 7, the techniques of this disclosure may reduce hemolysis associated with delivering PFA while maintaining an efficiency of the PFA procedure.

[0138] Example 1. A system comprising: a catheter configured to deliver pulsed field ablation (PFA) energy to patient tissue via a plurality of electrodes; and processing circuitry configured to: for each electrode of the plurality of electrodes of the catheter, determine a location of the electrode relative to one or more of the patient tissue, blood pool, or one or more sensitive structures based on two or more of: an impedance measurement; a sensed cardiac signal; or one or more of a tracked catheter or a tracked electrode location and for each electrode of the plurality of electrodes, based on a determination that the location of the electrode is not in contact with the patient tissue, that the location of the electrode is primarily in contact with the blood pool, or that the location of the electrode is within a threshold distance from one or more sensitive structures, determine to deactivate delivery of PFA energy via the electrode; and deliver PFA energy to patient tissue via electrodes of the plurality of electrodes through which delivery of PFA energy has not been deactivated.

[0139] Example 2. The system of example 1, wherein the processing circuitry determines to deactivate delivery of PFA energy via the electrode: before initiating PFA energy delivery; or in response to a determination that a risk of hemolysis meets a threshold risk level based on the location of the electrode being primarily in contact with the blood pool.

[0140] Example s. The system of example 2, wherein to determine the risk of hemolysis meets the threshold risk level, the processing circuitry is configured to: determine aDocket No.: A0013501W001 / 1289-032W001 number of applications of PF A energy delivered to the patient tissue; and compare the number of applications of PFA energy delivered to the patient tissue to a threshold risk level.

[0141] Example 4. The system of any of examples 1-3, wherein the processing circuitry is further configured to determine the location of the electrode based on a temperature measurement.

[0142] Example 5. The system of any of examples 1-4, wherein the PFA catheter is configured to both deliver ablation energy via PFA and to perform location mapping associated with the one or more of the tracked catheter location or the tracked electrode location.

[0143] Example 6. The system of any of examples 1-5, wherein to determine the location of the electrode based on the sensed cardiac signal, the processing circuitry is configured to determine the location of the electrode based on one or more of an amplitude of the sensed cardiac signal or one or more timing characteristics of the sensed cardiac signal.

[0144] Example 7. The system of any of examples 1-6, wherein location mapping associated with the one or more of the tracked catheter location or the tracked electrode location is based at least in part on one or more of an intracardiac echocardiography (ICE), a transthoracic echocardiogram (ECHO), a transesophageal echocardiogram (TEE), an X-ray, or fluoroscopy as an input.

[0145] Example 8. The system of any of examples 1-7, wherein the processing circuitry is configured to continuously determine the location of the electrode.

[0146] Example 9. The system of any of examples 1-8, wherein the processing circuitry is configured to: determine an updated location for each electrode of the plurality of electrodes; and determine, based on the updated location for each electrode, whether to switch an activation state of the electrode, wherein in a first instance and based on the updated location of the electrode being in contact with the patient tissue and the location of the electrode meeting a minimum threshold distance from the one or more sensitive structures, the processing circuitry is configured to switch the activation state from deactivated to activated, and wherein in a second instance and based on one or more of the electrode not being in contact with the patient tissue or the location of the electrode being within the threshold distance from the one or more sensitive structures, the processing circuitry is configured to switch the activation state from activated to deactivated if the updated location of the electrode.

[0147] Example 10. The system of any of examples 1-9, wherein the catheter comprises a first catheter, wherein the system comprises a second catheter configured to deliver cryoablation energy to the patient via a plurality of cry o-refrigerant jets, and wherein the processing circuitry is further configured to: for each cry o-refrigerant jet of the plurality of cryorefrigerant jets, determine a location of the cryo-refrigerant jet based on at least a tracked cryo-Docket No.: A0013501W001 / 1289-032W001 refrigerant jet location; based on a determination that a location of the cryo-refrigerant jet is not in contact with the patient tissue, that the location of the electrode is primarily in contact with the blood pool, or that the location of the cryo-refrigerant jet is within the threshold distance from the one or more sensitive structures, determine to deactivate delivery of cryoablation energy via the cryo-refrigerant jet; and deliver cryoablation energy to patient tissue via cryo-refrigerant jets of the plurality of cryo-refrigerant jets through which delivery of cryoablation energy has not been deactivated.

[0148] Example 11. The system of example 10, wherein the first catheter and the second catheter are the same catheter.

[0149] Example 12. The system of any of examples 1-11, wherein the one or more sensitive structures include one or more of an atrioventricular node (AV node), a sinoatrial (SA) node, one or more nerves, or one or more collateral organs.

[0150] Example 13. The system of any of examples 1-12, wherein the PFA energy delivery comprises cardiac ablation therapy for atrial fibrillation (AF).

[0151] Example 14. A method comprising: for each electrode of a plurality of electrodes of a catheter configured to deliver pulsed field ablation (PFA) energy to patient tissue via the plurality of electrodes, determining a location of the electrode relative to one or more of the patient tissue, blood pool, or one or more sensitive structures based on two or more of: an impedance measurement; a sensed cardiac signal; or one or more of a tracked catheter location or a tracked electrode location; and for each electrode of the plurality of electrodes, based on a determination that the location of the electrode is not in contact with the patient tissue, that the location of the electrode is primarily in contact with the blood pool, or that the location of the electrode is within a threshold distance from one or more sensitive structures, determining to deactivate delivery of PFA energy via the electrode; and delivering PFA energy to patient tissue via electrodes of the plurality of electrodes through which delivery of PFA energy has not been deactivated.

[0152] Example 15. The method of example 14, wherein determining to deactivate delivery of PFA energy via the electrode comprises determining to deactivate delivery of PFA energy via the electrode: before initiating PFA energy delivery; or in response to a determination that a risk of hemolysis meets a threshold risk level based on the location of the electrode being primarily in contact with the blood pool.

[0153] Example 16. The method of example 15, determining the risk of hemolysis meets the threshold risk level comprises: determining a number of applications of PFA energy delivered to the patient tissue; and comparing the number of applications of PFA energy delivered to the patient tissue to a threshold risk level.Docket No.: A0013501W001 / 1289-032W001

[0154] Example 17. The method of any of examples 14-16, further comprising determining the location of the electrode based on a temperature measurement.

[0155] Example 18. The method of any of examples 14-17, wherein the PFA catheter is configured to both deliver ablation energy via PFA and to perform location mapping associated with the one or more of the tracked catheter location or the tracked electrode location.

[0156] Example 19. The method of any of examples 14-18, wherein determining the location of the electrode based on the sensed cardiac signal comprises determining the location of the electrode based on one or more of an amplitude of the sensed cardiac signal or one or more timing characteristics of the sensed cardiac signal.

[0157] Example 20. The method of any of examples 14-19, wherein location mapping associated with the one or more of the tracked catheter location or the tracked electrode location is based at least in part on one or more of an intracardiac echocardiography (ICE), a transthoracic echocardiogram (ECHO), a transesophageal echocardiogram (TEE), an X-ray, or fluoroscopy as an input.

[0158] Example 21. The method of any of examples 14-20, further comprising continuously determining the location of the electrode.

[0159] Example 22. The method of any of examples 14-21, further comprising: determining an updated location for each electrode of the plurality of electrodes; and determining, based on the updated location for each electrode, whether to switch an activation state of the electrode, wherein in a first instance and based on the updated location of the electrode being in contact with the patient tissue and the location of the electrode meeting a minimum threshold distance from the one or more sensitive structures, processing circuitry of a system comprising the PFA catheter is configured to switch the activation state from deactivated to activated, and wherein in a second instance and based on one or more of the electrode not being in contact with the patient tissue or the location of the electrode being within the threshold distance from the one or more sensitive structures, the processing circuitry is configured to switch the activation state from activated to deactivated if the updated location of the electrode.

[0160] Example 23. The method of any of examples 14-22, wherein the catheter comprises a first catheter, and wherein the system comprises a second catheter configured to deliver cryoablation energy to the patient via a plurality of cry o-refrigerant jets, the method further comprising: for each cry o-refrigerant jet of the plurality of cry o-refrigerant jets, determining, by the processing circuitry, a location of the cry o-refrigerant jet based on at least a tracked cry o-refrigerant jet location; based on a determination that a location of the cryorefrigerant jet is not in contact with the patient tissue, that the location of the electrode is primarily in contact with the blood pool, or that the location of the cry o-refrigerant jet is withinDocket No.: A0013501W001 / 1289-032W001 the threshold distance from the one or more sensitive structures, determining, by the processing circuitry, to deactivate delivery of cryoablation energy via the cryo-refrigerant jet; and delivering, by the processing circuitry, cryoablation energy to patient tissue via cryo-refrigerant jets of the plurality of cryo-refrigerant jets through which delivery of cryoablation energy has not been deactivated.

[0161] Example 24. The method of example 23, wherein the first catheter and the second catheter are the same catheter.

[0162] Example 25. The method of any of examples 14-24, wherein the one or more sensitive structures include one or more of an atrioventricular node (AV node), a sinoatrial (SA) node, one or more nerves, or one or more collateral organs .

[0163] Example 26. The method of any of examples 14-25, wherein the PFA energy delivery comprises cardiac ablation therapy for atrial fibrillation (AF).

[0164] Example 27. A system comprising: a catheter configured to deliver pulsed field ablation (PFA) energy to patient tissue via a plurality of electrodes; and processing circuitry configured to: for each electrode of the plurality of electrodes of the catheter, determine a location of the electrode based on two or more of: an impedance measurement; a sensed cardiac signal; or one or more of a tracked catheter location or a tracked electrode location; and based on the determination of the location of the electrode, determine whether to activate delivery of PFA energy via the electrode, wherein the processing circuitry activates delivery of PFA energy via the electrode when the location of the electrode is in contact with patient tissue and when the location of the electrode meets a minimum threshold distance from one or more sensitive structures; and deliver PFA energy to patient tissue via electrodes of the plurality of electrodes through which delivery of PFA energy has been activated.

[0165] The techniques of this disclosure may be implemented, at least in part, in hardware, software, firmware or any combination thereof. For example, various aspects of the described techniques may be implemented within one or more processors or processing circuitry, 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 unit including hardware may also perform one or more of the techniques of this disclosure.

[0166] Such hardware, software, and firmware may be implemented within the same device or within separate devices to support the various operations and functions described in this disclosure. In addition, any of the described units, circuits or components may be implementedDocket No.: A0013501W001 / 1289-032W001 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.

[0167] 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 in 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 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.

[0168] Various examples have been described. These and other examples are within the scope of the following claims.

Claims

Docket No.: A0013501W001 / 1289-032W001 WHAT IS CLAIMED IS:

1. A system comprising:a catheter configured to deliver pulsed field ablation (PF A) energy to patient tissue via a plurality of electrodes; andprocessing circuitry configured to:for each electrode of the plurality of electrodes of the catheter, determine a location of the electrode relative to one or more of the patient tissue, blood pool, or one or more sensitive structures based on two or more of:an impedance measurement;a sensed cardiac signal; orone or more of a tracked catheter or a tracked electrode location; and for each electrode of the plurality of electrodes, based on a determination that the location of the electrode is not in contact with the patient tissue, that the location of the electrode is primarily in contact with the blood pool, or that the location of the electrode is within a threshold distance from one or more sensitive structures, determine to deactivate delivery of PF A energy via the electrode; anddeliver PFA energy to patient tissue via electrodes of the plurality of electrodes through which delivery of PFA energy has not been deactivated.

2. The system of claim 1, wherein the processing circuitry determines to deactivate delivery of PFA energy via the electrode before initiating PFA energy delivery.

3. The system of claim 1, wherein the processing circuitry determines to deactivate delivery of PFA energy via the electrode:in response to a determination that a risk of hemolysis meets a threshold risk level based on the location of the electrode being primarily in contact with the blood pool.

4. The system of claim 3, wherein to determine the risk of hemolysis meets the threshold risk level, the processing circuitry is configured to:determine a number of applications of PFA energy delivered to the patient tissue; and compare the number of applications of PFA energy delivered to the patient tissue to a threshold risk level.Docket No.: A0013501W001 / 1289-032W001 5. The system of any of claims 1-4, wherein the processing circuitry is further configured to determine the location of the electrode based on a temperature measurement.

6. The system of any of claims 1-5, wherein the PFA catheter is configured to both deliver ablation energy via PFA and to perform location mapping associated with the one or more of the tracked catheter location or the tracked electrode location.

7. The system of any of claims 1-6, wherein to determine the location of the electrode based on the sensed cardiac signal, the processing circuitry is configured to determine the location of the electrode based on one or more of an amplitude of the sensed cardiac signal or one or more timing characteristics of the sensed cardiac signal.

8. The system of any of claims 1-7, wherein location mapping associated with the one or more of the tracked catheter location or the tracked electrode location is based at least in part on one or more of an intracardiac echocardiography (ICE), a transthoracic echocardiogram (ECHO), a transesophageal echocardiogram (TEE), an X-ray, or fluoroscopy as an input.

9. The system of any of claims 1-8, wherein the processing circuitry is configured to continuously determine the location of the electrode.

10. The system of any of claims 1-9 wherein the processing circuitry is configured to: determine an updated location for each electrode of the plurality of electrodes; and determine, based on the updated location for each electrode, whether to switch an activation state of the electrode,wherein in a first instance and based on the updated location of the electrode being in contact with the patient tissue and the location of the electrode meeting a minimum threshold distance from the one or more sensitive structures, the processing circuitry is configured to switch the activation state from deactivated to activated, andwherein in a second instance and based on one or more of the electrode not being in contact with the patient tissue or the location of the electrode being within the threshold distance from the one or more sensitive structures, the processing circuitry is configured to switch the activation state from activated to deactivated if the updated location of the electrode.

11. The system of any of claims 1-10, wherein the catheter comprises a first catheter, wherein the system comprises a second catheter configured to deliver cryoablation energy to theDocket No.: A0013501W001 / 1289-032W001 patient via a plurality of cry o-refrigerant jets, and wherein the processing circuitry is further configured to:for each cryo-refrigerant jet of the plurality of cry o-refrigerant jets, determine a location of the cryo-refrigerant jet based on at least a tracked cryo-refrigerant jet location;based on a determination that a location of the cryo-refrigerant jet is not in contact with the patient tissue, that the location of the electrode is primarily in contact with the blood pool, or that the location of the cryo-refrigerant jet is within the threshold distance from the one or more sensitive structures, determine to deactivate delivery of cryoablation energy via the cryo-refrigerant jet; anddeliver cryoablation energy to patient tissue via cryo-refrigerant jets of the plurality of cryo-refrigerant jets through which delivery of cryoablation energy has not been deactivated.

12. The system of claim 11, wherein the first catheter and the second catheter are the same catheter.

13. The system of any of claims 1-12, wherein the one or more sensitive structures include one or more of an atrioventricular (AV) node, a sinoatrial (SA) node, one or more nerves, or one or more collateral organs.

14. The system of any of claims 1-13, wherein the PFA energy delivery comprises cardiac ablation therapy.

15. The system of any of claims 1-14, wherein the PFA energy delivery comprises therapy for atrial fibrillation (AF).

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