Systems and methods for detecting deployment of electroporation ablation catheters

Abstract

A system and method for an electroporation ablation catheter is provided. At least some embodiments of the present disclosure are directed to systems and methods for estimating the positions of electrodes and / or electrode assemblies of an electroporation ablation catheter as the catheter is deployed. In some examples, the positions of the electrodes are estimated using electrical signals collected when current is injected through tracking electrodes. In particular examples, the positions of the electrodes are updated using one or more geometric models associated with the electroporation ablation catheter.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to medical systems and methods for ablating tissue in a patient, and more particularly, to medical systems and methods for ablation of tissue by electroporation. [Background technology]

[0002] Ablation procedures are used to treat many different conditions in patients. Ablation can be used to treat cardiac arrhythmias, benign tumors, cancerous tumors, and to control bleeding during surgery. Ablation is typically performed using thermal ablation techniques, including radiofrequency (RF) ablation and cryoablation. In RF ablation, a probe is inserted into the patient, and radiofrequency waves are transmitted through the probe to surrounding tissue. The radiofrequency waves generate heat, which destroys surrounding tissue and cauterizes blood vessels. In cryoablation, a hollow needle, or cryoprobe, is inserted into the patient, and a low-temperature, heat-conducting fluid is circulated through the probe, freezing and destroying surrounding tissue. RF ablation and cryoablation techniques indiscriminately destroy tissue through cell necrosis, which can damage or destroy otherwise healthy tissue, such as tissue in the esophagus, phrenic nerve cells, and tissue in the coronary arteries.

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

[0004] Irreversible electroporation can be used as a non-thermal ablation technique. It uses a train of short, high-voltage pulses to generate an electric field strong enough to kill cells by apoptosis. For cardiac tissue ablation, irreversible electroporation may be a safe and effective alternative to the indiscriminate destruction of cells from thermal ablation techniques such as RF ablation and cryoablation. Irreversible electroporation can be used to kill targeted tissue, such as myocardial tissue, by using an electric field strength and duration that kills the target tissue but does not permanently damage other cells or tissues, such as non-target myocardial tissue, red blood cells, vascular smooth muscle tissue, endothelial tissue, and nerve cells. Planning and / or facilitating electroporation ablation procedures can be difficult due to the lack of visualization or data indicating the position, condition, and / or shape of the catheter and electrode assembly before and during the ablation procedure. Summary of the Invention

[0005] In Example 1, a system for electroporation ablation includes one or more tracking electrodes configured to deliver a tracking current, an ablation catheter including an electrode assembly including a plurality of splines and a plurality of electrodes, and one or more processors. At least one of the plurality of electrodes is disposed on the plurality of splines, and the ablation catheter is positioned proximate to the target tissue, the plurality of electrodes including a sensing electrode, the sensing electrode configured to measure an electrical signal when the tracking current is delivered. The one or more processors can be configured to receive the measured electrical signal, estimate at least one electrode position corresponding to at least one of the plurality of electrodes based on the measured electrical signal, and update the at least one electrode position corresponding to at least one of the plurality of electrodes based on a geometric model of the ablation catheter.

[0006] In Example 2, in the system of Example 1, the one or more processors are further configured to access a field map and estimate at least one electrode position corresponding to at least one of the plurality of electrodes based on the measured electrical signal and the field map.

[0007] In Example 3, in the system of Example 2, the field map is generated by a mapping catheter. In Example 4, in the system of Example 2, the ablation catheter further comprises a navigation sensor, and the one or more processors are configured to generate a field map based on sensing signals collected by the sensing electrodes, the sensing electrodes having known positions relative to the navigation sensor.

[0008] In Example 5, in the system of any of Examples 1-4, the geometric model includes one or more constraints regarding one or more relative electrode positions of the plurality of electrodes. In Example 6, in the system of Example 5, the geometric model includes relative electrode positions of two electrodes positioned on one spline of the plurality of splines.

[0009] In Example 7, in the system of Example 5, the geometric model may include relative electrode positions of two or more electrodes, each electrode of the two or more electrodes being positioned on a respective spline of the plurality of splines.

[0010] In Example 8, in the system of Example 7, the ablation catheter includes a longitudinal axis defined by the catheter shaft, the electrode assembly extends from the catheter shaft, and the two or more electrodes form a plane generally perpendicular to the longitudinal axis.

[0011] In Example 9, the system of any of Examples 1-8, wherein the geometric model includes a first predetermined radius range of a first portion of a spline of the plurality of splines. In Example 10, in the system of Example 9, the geometric model includes a second predetermined radius range for a second portion of the one spline of the plurality of splines, the second portion of the one spline of the plurality of splines being different from the first portion of the one spline of the plurality of splines, and the second predetermined radius range being different from the first predetermined radius range.

[0012] In Example 11, the system of any of Examples 1-10 further includes a deployment sensor configured to collect data related to the deployment state, and the one or more processors configured to receive the collected data related to the deployment state and select a geometric model based on the collected data.

[0013] In Example 12, the system of any of Examples 1-11, wherein the one or more tracking electrodes include a first tracking electrode configured to be placed on a body surface of the patient.

[0014] In Example 13, the system of any of Examples 1-12, wherein the one or more tracking electrodes includes a second tracking electrode configured to be positioned within a chamber of the patient's heart. In Example 14, a method of electroporation ablation includes deploying an ablation catheter proximate to a target tissue, deploying one or more tracking electrodes at one or more target locations, injecting current via the one or more tracking electrodes, measuring an electrical signal via at least one of the plurality of electrodes, estimating an electrode position corresponding to one of the plurality of electrodes based on the measured electrical signal, and updating the electrode position based on a geometric model of the ablation catheter. The ablation catheter may include an electrode assembly, the electrode assembly including a plurality of splines and a plurality of electrodes, at least one of the plurality of electrodes disposed on the plurality of splines.

[0015] In Example 15, the method of Example 14 further includes accessing a field map, and the electrode positions are estimated based on the measured electrical signals and the field map. In Example 16, a system for electroporation ablation includes one or more tracking electrodes configured to deliver a tracking current, an ablation catheter including an electrode assembly including a plurality of splines and a plurality of electrodes, and one or more processors. At least one of the plurality of electrodes is disposed on the plurality of splines, and the ablation catheter is positioned proximate to the target tissue, the plurality of electrodes including a sensing electrode, the sensing electrode configured to measure an electrical signal when the tracking current is delivered. The one or more processors can be configured to receive the measured electrical signal, estimate at least one electrode position corresponding to at least one of the plurality of electrodes based on the measured electrical signal, and update the at least one electrode position corresponding to at least one of the plurality of electrodes based on a geometric model of the ablation catheter.

[0016] In Example 17, in the system of Example 16, the one or more processors are further configured to access a field map and estimate at least one electrode position corresponding to at least one of the plurality of electrodes based on the measured electrical signal and the field map.

[0017] In Example 18, in the system of Example 17, the field map is generated by a mapping catheter. In Example 19, in the system of Example 17, the ablation catheter further comprises a navigation sensor, and the one or more processors are configured to generate a field map based on sensing signals collected by the sensing electrodes, the sensing electrodes having known positions relative to the navigation sensor.

[0018] In Example 20, in the system of Example 16, the geometric model includes one or more constraints regarding one or more relative electrode positions of the plurality of electrodes. In Example 21, in the system of Example 20, the geometric model includes relative electrode positions of two electrodes positioned on one spline of the plurality of splines.

[0019] In Example 22, in the system of Example 20, the geometric model may include relative electrode positions of two or more electrodes, each electrode of the two or more electrodes being positioned on a respective spline of the plurality of splines.

[0020] In Example 23, in the system of Example 22, the ablation catheter includes a longitudinal axis defined by the catheter shaft, the electrode assembly extends from the catheter shaft, and the two or more electrodes form a plane that is approximately perpendicular to the longitudinal axis.

[0021] In Example 24, in the system of Example 16, the geometric model includes a first predetermined radius range of a first portion of one of the plurality of splines. In Example 25, in the system of Example 24, the geometric model includes a second predetermined radius range for a second portion of the one spline of the plurality of splines, the second portion of the one spline of the plurality of splines being different from the first portion of the one spline of the plurality of splines, and the second predetermined radius range being different from the first predetermined radius range.

[0022] In Example 26, the system of Example 16 further includes a deployment sensor configured to collect data related to the deployment state, wherein the one or more processors are configured to receive the collected data related to the deployment state and select a geometric model based on the collected data.

[0023] In Example 27, the system of Example 16, wherein the one or more tracking electrodes includes a first tracking electrode configured to be placed on a body surface of the patient. In Example 28, the system of Example 16, wherein the one or more tracking electrodes includes a second tracking electrode configured to be positioned within a chamber of the patient's heart.

[0024] In Example 29, a method of electroporation ablation includes deploying an ablation catheter proximate to a target tissue, deploying one or more tracking electrodes at one or more target locations, injecting current via the one or more tracking electrodes, measuring an electrical signal via at least one of the plurality of electrodes, estimating an electrode position corresponding to one of the plurality of electrodes based on the measured electrical signal, and updating the electrode position based on a geometric model of the ablation catheter. The ablation catheter may include an electrode assembly, the electrode assembly including a plurality of splines and a plurality of electrodes, at least one of the plurality of electrodes disposed on the plurality of splines.

[0025] In Example 30, the method of Example 29 further includes accessing a field map, and the electrode positions are estimated based on the measured electrical signals and the field map. In Example 31, a system for electroporation ablation includes one or more tracking electrodes configured to deliver a tracking current, an ablation catheter including an electrode assembly including a plurality of splines and a plurality of electrodes, and one or more processors. At least one of the plurality of electrodes is disposed on the plurality of splines, and the ablation catheter is positioned proximate to target tissue, the plurality of electrodes including a sensing electrode, the sensing electrode configured to measure an electrical signal when the tracking current is delivered. The electrode assembly has a plurality of deployment states, and when the electrode assembly is in a first state of the plurality of deployment states, the electrode assembly is in a first shape, and when the electrode assembly is in a second state of the plurality of deployment states, the electrode assembly is in a second shape, the first state corresponding to a first geometric model, and the second state corresponding to a second geometric model. The one or more processors may be configured to receive the measured electrical signals, estimate at least one electrode position corresponding to at least one of the plurality of electrodes based on the measured electrical signals, select a selected geometric model from the first geometric model and the second geometric model, and update the at least one electrode position corresponding to at least one of the plurality of electrodes based on the selected geometric model of the ablation catheter.

[0026] In Example 32, in the system of Example 31, the one or more processors are further configured to access a field map and estimate at least one electrode position corresponding to at least one of the plurality of electrodes based on the measured electrical signal and the field map.

[0027] In Example 33, in the system of Example 31, the geometric model includes one or more constraints regarding one or more relative electrode positions of the plurality of electrodes. In Example 34, in the system of Example 33, the geometric model includes relative electrode positions of two electrodes of the plurality of electrodes positioned on one spline of the plurality of splines.

[0028] In Example 35, the system of Example 31 further comprises a deployment sensor configured to collect data related to the deployment state, wherein the one or more processors are configured to receive the collected data related to the deployment state and select a geometric model based on the collected data.

[0029] While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 illustrates an exemplary clinical environment for treating a patient and treating the patient's heart using an electrophysiological system according to an embodiment of the presently disclosed subject matter. [Figure 2A] 2A-2B are schematic diagrams illustrating electroporation ablation catheters in various states that can be used for electroporation ablation, including irreversible electroporation ablation, according to embodiments of the presently disclosed subject matter. [Figure 2B] 2A-2B are schematic diagrams illustrating electroporation ablation catheters in various states that can be used for electroporation ablation, including irreversible electroporation ablation, according to embodiments of the presently disclosed subject matter. [Figure 3A] 3A-3C are schematic diagrams illustrating ablation catheters in various states that can be used for electroporation ablation, including irreversible electroporation ablation, according to embodiments of the presently disclosed subject matter. [Figure 3B]3A-3C are schematic diagrams illustrating ablation catheters in various states that can be used for electroporation ablation, including irreversible electroporation ablation, according to embodiments of the presently disclosed subject matter. [Figure 3C] 3A-3C are schematic diagrams illustrating ablation catheters in various states that can be used for electroporation ablation, including irreversible electroporation ablation, according to embodiments of the presently disclosed subject matter. [Figure 4A] 4A-4D are schematic diagrams illustrating embodiments of ablation catheters that can be used for electroporation ablation, including irreversible electroporation ablation, in accordance with embodiments of the presently disclosed subject matter. [Figure 4B] 4A-4D are schematic diagrams illustrating embodiments of ablation catheters that can be used for electroporation ablation, including irreversible electroporation ablation, in accordance with embodiments of the presently disclosed subject matter. [Figure 4C] 4A-4D are schematic diagrams illustrating embodiments of ablation catheters that can be used for electroporation ablation, including irreversible electroporation ablation, in accordance with embodiments of the presently disclosed subject matter. [Figure 4D] 4A-4D are schematic diagrams illustrating embodiments of ablation catheters that can be used for electroporation ablation, including irreversible electroporation ablation, in accordance with embodiments of the presently disclosed subject matter. [Figure 5A] 5A-5D are schematic diagrams illustrating a solid-core inductive sensor and an air-core inductive sensor, respectively, according to embodiments of the disclosed subject matter. [Figure 5B] 5A-5D are schematic diagrams illustrating a solid-core inductive sensor and an air-core inductive sensor, respectively, according to embodiments of the disclosed subject matter. [Figure 5C] 5A-5D are schematic diagrams illustrating a solid-core inductive sensor and an air-core inductive sensor, respectively, according to embodiments of the disclosed subject matter. [Figure 5D] 5A-5D are schematic diagrams illustrating a solid-core inductive sensor and an air-core inductive sensor, respectively, according to embodiments of the disclosed subject matter. [Figure 6] FIG. 6 is a schematic diagram showing a catheter shaft. [Figure 7A] 7A-7B are schematic diagrams illustrating an ablation catheter 700 including a deployed electrode assembly and one or more tracking electrodes, according to an embodiment of the presently disclosed subject matter. [Figure 7B] 7A-7B are schematic diagrams illustrating an ablation catheter 700 including a deployed electrode assembly and one or more tracking electrodes, according to an embodiment of the presently disclosed subject matter. [Figure 8] FIG. 8 is a flow chart diagram illustrating a process for facilitating ablation by irreversible electroporation, according to an embodiment of the presently disclosed subject matter. [Figure 9A] 9A-9E are flow and system diagrams illustrating a process for facilitating ablation by irreversible electroporation, according to an embodiment of the presently disclosed subject matter. [Figure 9B] 9A-9E are flow and system diagrams illustrating a process for facilitating ablation by irreversible electroporation, according to an embodiment of the presently disclosed subject matter. [Figure 9C] 9A-9E are flow and system diagrams illustrating a process for facilitating ablation by irreversible electroporation, according to an embodiment of the presently disclosed subject matter. [Figure 9D] 9A-9E are flow and system diagrams illustrating a process for facilitating ablation by irreversible electroporation, according to an embodiment of the presently disclosed subject matter. [Figure 9E]9A-9E are flow and system diagrams illustrating a process for facilitating ablation by irreversible electroporation, according to an embodiment of the presently disclosed subject matter. DETAILED DESCRIPTION OF THE INVENTION

[0031] While the invention is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.

[0032] The following detailed description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the present invention in any way. Rather, the following description provides some practical illustrations for implementing exemplary embodiments of the present invention. Examples of configurations, materials, and / or dimensions are provided for selected elements. Those skilled in the art will recognize that many of the described examples have a variety of suitable alternatives.

[0033] As used herein with respect to measurements (e.g., dimensions, characteristics, attributes, components, etc.) and ranges thereof of tangible (e.g., products, inventory, etc.) and / or intangible (e.g., data, electronic representations of currency, accounts, information, parts of things (e.g., percentages, fractions), calculations, data models, dynamic system models, algorithms, parameters, etc.), "about" and "approximately" mean a measurement that is inclusive of the stated measurement and reasonably close to the stated measurement, but which may be subject to measurement error, differences in calibration of measuring and / or manufacturing equipment, human error in reading and / or setting measurements, other measurements (e.g., other related to "measurements" may be used interchangeably to refer to measurements that also include any measurements that may differ by reasonably small amounts as understood and readily identified by those skilled in the art due to adjustments made to optimize performance and / or structural parameters taking into account related measurements, imprecise adjustment and / or manipulation of objects, settings, and / or measurements by a particular implementation scenario, humans, computing devices, and / or machines, system tolerances, control loops, machine learning, predictable variations (e.g., statistically insignificant variations, chaotic variations, system and / or model instability, etc.), preferences, and / or the like.

[0034] Although an example method may be represented by one or more drawings (e.g., flow diagrams, communication flows, etc.), the drawings should not be construed as implying any requirement of, or a particular order between, the various steps disclosed herein. However, some embodiments may require certain steps and / or a particular order between certain steps (e.g., the operation of some steps may depend on the results of previous steps), as may be explicitly described herein and / or understood from the nature of the steps themselves. Additionally, a "set," "subset," or "group" of items (e.g., inputs, algorithms, data values, etc.) may include one or more items, and similarly, a subset or subgroup of items may include one or more items. "Plurality" means more than one.

[0035] As used herein, the term "based on" is not meant to be limiting, but rather indicates that a determination, identification, prediction, calculation, and / or the like is performed by using at least the term preceding "based on" as an input. For example, predicting an outcome based on particular information may additionally or alternatively base the same determination on other information.

[0036] Irreversible electroporation (IRE) uses short (e.g., 100 microseconds or less) pulses of high voltage to kill cells through apoptosis. IRE can be targeted to destroy myocardium while sparing other adjacent tissues, including esophageal vascular smooth muscle and endothelium. IRE therapy can be delivered in multiple treatment sections. A treatment section (e.g., 10 milliseconds in duration) may include multiple electrical pulses (e.g., 20 pulses, 30 pulses, etc.) generated and delivered by an electroporation device supplied by an electroporation generator.

[0037] To determine electrode and / or electrode assembly positions of an electroporation ablation catheter within a conductive medium (e.g., an intracardiac space) using electric field localization techniques (e.g., impedance tracking), in some embodiments, a system is configured to inject a current to generate an electric field and measure the resulting potential from electrodes of the electroporation ablation catheter having an unknown 3D position. The current can be injected using tracking electrodes whose surfaces are exposed to the conductive medium. The tracking electrode surfaces can be located on the surface of the medium (e.g., a patient's skin) or within the medium (e.g., within a patient's blood vessel / heart chamber). The system can collect electrical signals from one or more electrodes of the catheter as current is injected via the tracking electrodes.

[0038] Some mapping systems use electrical signals collected in the context of a field map to determine the position of one or more electrodes and / or electrode assemblies, and some mapping systems do so without the context of a field map. Electrodes in electroporation ablation catheters can function as ablation electrodes for generating ablation fields, sensing electrodes for measuring field signals, mapping electrodes for measuring electrical signals to generate an electroanatomical map, tracking electrodes for injecting electrical current, and combinations thereof.

[0039] At least some embodiments of the present disclosure are directed to systems and methods for estimating the position (also referred to as location) of electrodes and / or electrode assemblies of an electroporation ablation catheter. At least some embodiments of the present disclosure are directed to systems and methods for estimating the position of electrodes and / or electrode assemblies of an electroporation ablation catheter by tracking the electrodes. In some examples, the electrodes are tracked using measured electrical signals when current is injected through one or more tracking electrodes. In certain examples, the positions of the electrodes are updated and / or refined using one or more geometric models corresponding to the electroporation ablation catheter.

[0040] As used herein, a geometric model refers to a mathematical model that represents a shape, a shape associated with a range of variation, a predetermined shape, an estimated shape, a predicted shape, a dynamic shape, an adjusted shape, a set of rules associated with one or more shapes, a set of rules associated with a predetermined relative position, a set of constraints associated with a shape, a set of constraints associated with a predetermined relative position, one or more geometric functions, and / or one or more functions relating to relationships between components. In some embodiments, a geometric model is associated with a particular shape. As used herein, shape refers to a two-dimensional or three-dimensional shape of a particular size. In certain embodiments, a geometric model is associated with multiple shapes. In some embodiments, systems and methods use estimated positions associated with electrodes and / or electrode assemblies to facilitate the ablation process. As used herein, "facilitating ablation" includes planning prior to the ablation procedure, providing localization information, and / or providing visualization guidance to assist in ablation during the ablation procedure.

[0041] FIG. 1 illustrates an exemplary clinical environment 10 for treating a patient 20 and for treating a heart 30 of the patient 20 using an electrophysiology system 50 in accordance with an embodiment of the presently disclosed subject matter. The electrophysiology system 50 includes an electroporation device 60, a display 92, and an optional localization field generator 80. The clinical environment 10 also includes additional equipment, such as imaging equipment 94 (represented by a C-arm), and various control elements configured to allow an operator to control various aspects of the electrophysiology system 50. As will be appreciated by those skilled in the art, the clinical environment 10 may have other components and arrangements of components not shown in FIG. 1 .

[0042] The electroporation device 60 includes an electroporation catheter 105, an introducer sheath 110, a controller 90, and an electroporation generator 130. In embodiments, the electroporation device 60 is configured to deliver electric field energy to target tissue within the patient's heart 30 to induce apoptosis in the tissue, rendering it unable to conduct electrical signals. In certain embodiments, the electroporation device 60 has multiple states, also referred to as operational or deployed states, when used to ablate tissue. In some examples, the electroporation device 60 includes one or more tracking electrodes that can facilitate estimation and determination of the position of the electrodes of the electroporation catheter 105, the position of the electrode assembly 150 of the electroporation catheter 105, and / or the shape of the electrode assembly 150 of the electroporation catheter 105. In some embodiments, at least some of the multiple electrodes of the electroporation catheter 105 are ablation electrodes configured to generate an electric field for ablation during an ablation procedure.

[0043] In some embodiments, the electroporation device 60 is configured to generate a graphical representation of the electric field that can be generated using the electroporation catheter 105 based on a model of the electric field, and to overlay the graphical representation of the electric field on an anatomical map of the patient's heart, as presented on the display 92, to assist the user in planning and / or facilitating irreversible electroporation ablation using the electroporation catheter 105 (e.g., planning ablation before the ablation procedure and facilitating ablation during the ablation procedure by tracking the position of the electrode assembly 150).

[0044] In an embodiment, electroporation device 60 is configured to generate a graphical representation of the electric field based on characteristics of electroporation catheter 105 and the position of electroporation catheter 105 within patient 20, such as within heart 30 of patient 20. In an embodiment, electroporation device 60 is configured to generate a graphical representation of the electric field based on characteristics of electroporation catheter 105 and the position of electroporation catheter 105 within patient 20, such as within heart 30 of patient 20, and characteristics of the tissue surrounding catheter 105, such as the measured impedance of the tissue.

[0045] Controller 90 is configured to control functional aspects of electroporation device 60. In an embodiment, controller 90 is configured to control electroporation generator 130 to generate electrical pulses, e.g., to control the magnitude, timing, and duration of the electrical pulses. In an embodiment, electroporation generator 130 is operable as a pulse generator to generate and deliver a pulse sequence to electroporation catheter 105.

[0046] In embodiments, the introducer sheath 110 is operable to provide a delivery conduit through which the electroporation catheter 105 may be deployed to a particular target site within the patient's heart 30. However, it should be understood that the introducer sheath 110 is illustrated and described herein to provide context for the electrophysiology system 50 as a whole.

[0047] 1 is intended to provide a general overview of the various components of the system 50 and is in no way intended to suggest that the present disclosure is limited to that set of components or arrangement of components. For example, one skilled in the art will readily recognize that additional hardware components, such as breakout boxes, workstations, and the like, can and likely will be included within the electrophysiology system 50.

[0048] In the illustrated embodiment, electroporation catheter 105 includes handle 105a, shaft 105b, and electrode assembly 150. Handle 105a is configured to be manipulated by a user to position electrode assembly 150 at a desired anatomical location. Shaft 105b has a distal end 105c and generally defines a longitudinal axis of electroporation catheter 105. As shown, electrode assembly 150 is located at or proximate distal end 105c of shaft 105b. In an embodiment, electrode assembly 150 is electrically coupled to electroporation generator 130 to receive an electrical pulse sequence or train, thereby selectively generating an electric field for ablating target tissue by irreversible electroporation.

[0049] 1, electrode assembly 150 includes one or more electrodes 152. Electrodes 152 may include ablation electrodes and, optionally, mapping electrodes. In some configurations, the mapping electrodes are configured to be used to collect electrical signals used to generate and display via display 92 a detailed three-dimensional geometrical anatomical map or representation of the heart chambers, as well as an electroanatomical map in which cardiac electrical activity of interest is superimposed on the geometrical anatomical map.

[0050] In certain embodiments, the electroporation catheter 105 is a catheter including an electrode assembly 150 having multiple states. In embodiments, the electrode assembly 150 has a first shape when the catheter 105 is in a first state of the multiple states and a second shape when the catheter 105 is in a second state of the multiple states. In some examples, the electrode assembly 150 has three or more states (e.g., three states, five states, continuously varying states). In certain examples, the electrode assembly 150 has respective contours, also referred to as respective shapes (e.g., a contour having a different shape from another contour, a contour having the same shape but a different size from another contour). In some examples, the electrode assembly 150 includes one or more splines and one or more electrodes, with at least some or all of the one or more electrodes disposed on the one or more splines. In embodiments, at least some of the one or more electrodes are configured to generate an ablation field at the target tissue in response to a plurality of electrical pulse sequences.

[0051] In some embodiments, the electroporation catheter 105 includes a navigation sensor 120 (or sometimes referred to as a set of navigation sensors) configured to collect sensor data related to the position of the electrode assembly 150, the position(s) of one or more components of the electrode assembly 150 (e.g., shaft, tip, splines, electrodes, etc.), and / or the position of one or more electrodes 152 of the electrode assembly 150. In certain embodiments, the sensor data collected by the navigation sensor 120 is measured when the localization field generator 80 is generating a magnetic field. In some embodiments, the navigation sensor 120 includes a first sensor disposed on one of the one or more splines. As used herein, the position of the electrode assembly 150 can refer to the position of one or more components of the electrode assembly 150. In some examples, the navigation sensor 120 collects electrical signals to determine the position of the navigation sensor 120, which in turn facilitates further determining the position of the electrode assembly 150. In some embodiments, the electroporation catheter 105 includes a central shaft disposed within a cavity formed by one or more splines, and the navigation sensor 120 includes a second sensor disposed on the central shaft. In certain embodiments, the electroporation catheter 105 further includes a catheter shaft, the electrode assembly 150 extends from the catheter shaft, and the navigation sensor 120 includes a third sensor (e.g., a catheter shaft sensor) disposed on the catheter shaft.

[0052] In an embodiment, navigation sensor 120 includes a 6-degree-of-freedom (DOF) sensor (e.g., a micro 6-DOF sensor). In some embodiments, navigation sensor 120 includes an inductive sensor. In some embodiments, navigation sensor 120 includes two 5-DOF sensors. In some examples, navigation sensor 120 includes two 5-DOF sensors, each disposed on a respective spline of one or more splines of electrode assembly 150. In particular examples, navigation sensor 120 includes an inductive sensor integrated with one of the one or more splines. In some examples, navigation sensor 120 includes an inductive sensor disposed on a central shaft. In particular examples, navigation sensor 120 includes a magnetoresistive (MR) sensor disposed on one of the one or more splines, the central shaft, the distal end of the catheter shaft, and / or the distal cap of electrode assembly 150.

[0053] In embodiments, electroporation device 60 may include one or more tracking electrodes configured to deliver electrical current. The tracking electrodes may include one or more electrodes disposed on the body surface of patient 20 (e.g., on the back of patient 20 or on the chest of patient 20), within a cardiac chamber of patient 20, and / or one or more electrodes of electroporation catheter 105.

[0054] In embodiments, system 50 may include one or more sensing electrodes (e.g., one or more electrodes of electroporation catheter 105) configured to measure electrical signals when current is delivered by the tracking electrodes. In embodiments, controller 90 is configured to receive the measured electrical signals, estimate at least one electrode position corresponding to at least one of the one or more ablation electrodes based on the measured electrical signals, and update the at least one electrode position corresponding to at least one of the one or more ablation electrodes based on a geometric model of the ablation catheter. In certain embodiments, controller 90 is configured to access multiple geometric models, each corresponding to a state of electroporation catheter 105 and a predetermined contour or shape of electrode assembly 150 of electroporation catheter 105.

[0055] In some embodiments, the electroporation device 60 includes one or more deployment sensors 106 configured to collect sensor data related to the deployment state of the electroporation catheter 105. The one or more deployment sensors 106 may include sensors disposed on the handle 105a (as shown) and / or sensors disposed on the electrode assembly 150 of the electroporation catheter 105 (e.g., proximate a cap of the electrode assembly 150). In some examples, the controller 90 is configured to determine the deployment state based on the sensor data collected by the one or more deployment sensors 106. In particular examples, the controller 90 is configured to select a geometric model based on the determined deployment state. In some examples, the controller 90 is configured to select a geometric model based on the sensor data collected by the one or more deployment sensors 106 and electrical signals measured by one or more sensing electrodes.

[0056] In certain embodiments, the controller 90 is further configured to access a field map and estimate at least one electrode position corresponding to at least one of the one or more ablation electrodes based on the measured electrical signals and the field map. In embodiments, the field map is generated by a separate mapping catheter. In embodiments, the field map is generated by mapping electrodes of the electroporation catheter 105.

[0057] In some embodiments, one or more mapping electrodes on the electroporation catheter 105 can measure electrical signals and generate output signals that can be processed by the controller 90 to generate an electroanatomical map, also referred to as an anatomical map. In some examples, the electroanatomical map is generated before ablation to determine the electrical activity of cardiac tissue within a chamber of interest. In some examples, the electroanatomical map is generated after ablation to verify desired changes in the electrical activity of the ablated tissue and the entire heart chamber. The mapping electrodes may be used to determine the position of the catheter 105 in three-dimensional space within the body. For example, as the operator moves the distal end of the catheter 105 within a heart chamber of interest, the boundaries of the catheter movement can be used by the controller 90, which may include or be coupled to a mapping and navigation system, to form an anatomical map of the heart chamber. The anatomical map of the chamber can be used to facilitate navigation of the catheter 105 without the use of ionizing radiation, such as fluoroscopy, and to tag the location of the ablation when the ablation is completed to guide the ablation interval and assist the operator in completely ablating the anatomical structure of interest.

[0058] According to embodiments, various components of electrophysiological system 50 (e.g., controller 90) may be implemented on one or more computing devices. The computing devices may include any type of computing device suitable for implementing embodiments of the present disclosure. Examples of computing devices include dedicated or general-purpose computing devices such as workstations, servers, laptops, portable devices, desktops, tablet computers, handheld devices, general-purpose graphics processing units (GPGPUs), and the like, all of which are contemplated within the scope of FIG. 1 with respect to various components of system 50.

[0059] In some embodiments, a computing device includes a bus that directly and / or indirectly couples the following devices: a processor, memory, input / output (I / O) ports, I / O components, and a power supply. Any number of additional components, different components, and / or combinations of components may be included in a computing device. A bus represents what may be one or more buses (e.g., an address bus, a data bus, or a combination thereof). Similarly, in some embodiments, a computing device may include multiple processors, multiple memory components, multiple I / O ports, multiple I / O components, and / or multiple power supplies. Additionally, any number of these components, or combinations thereof, may be distributed and / or replicated across multiple computing devices. In some embodiments, various components or portions of components (e.g., controller 90, electroporation catheter 105, etc.) may be integrated into a physical device.

[0060] In some embodiments, system 50 includes one or more memories (not shown). The one or more memories include computer-readable media in the form of volatile and / or non-volatile memory, transient and / or non-transitory storage media, and may be removable, non-removable, or a combination thereof. Examples of media include random access memory (RAM), read-only memory (ROM), electronically erasable programmable read-only memory (EEPROM), flash memory, optical or holographic media, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, data transmission, and / or any other medium that can be used to store information and that can be accessed by a computing device, such as, for example, quantum state memory and / or the like. In some embodiments, the one or more memories store computer-executable instructions that cause a processor (e.g., controller 90) to implement aspects of embodiments of the system components described herein and / or perform aspects of embodiments of the methods and procedures described herein.

[0061] Computer-executable instructions may include, for example, computer code, machine-usable instructions, program components, and the like, executable by, for example, one or more processors associated with a computing device. The program components may be programmed using any number of different programming environments, including various languages, development kits, frameworks, and / or the like. Some or all of the functionality contemplated herein may additionally or alternatively be implemented in hardware and / or firmware.

[0062] In some embodiments, the memory may include a data repository, which may be implemented using any one of the configurations described below. The data repository may include random access memory, flat files, XML files, and / or one or more database management systems (DBMS) running on one or more database servers or data centers. The database management system may be a relational (RDBMS), hierarchical (HDBMS), multidimensional (MDBMS), object-oriented (ODBMS or OODBMS), or object-relational (ORDBMS) database management system, etc. The data repository may be, for example, a single relational database. In some cases, the data repository may include multiple databases that can exchange and aggregate data through a data integration process or software application. In exemplary embodiments, at least a portion of the data repository may be hosted in a cloud data center. In some cases, the data repository may be hosted on a single computer, server, storage device, cloud server, etc. In some other cases, the data repository may be hosted on a series of networked computers, servers, or devices. In some cases, the data repository may be hosted on tiers of data storage devices, including local, regional, and central.

[0063] The various components of the system 50 may communicate or be coupled via communication interfaces, e.g., wired or wireless interfaces. Communication interfaces include, but are not limited to, any wired or wireless short-range and long-range communication interfaces. Wired interfaces may use cables, umbilicals, etc. Short-range communication interfaces may be, for example, interfaces that comply with known communication standards such as a local area network (LAN), Bluetooth® standards, IEEE 802 standards (e.g., IEEE 802.11), ZigBee® or similar specifications, such as those based on the IEEE 802.15.4 standard, or other public or proprietary wireless protocols. Long-range communication interfaces may be, for example, wide area networks (WANs), cellular network interfaces, satellite communication interfaces, etc. Communication interfaces may be within a private computer network, such as an intranet, or over a public computer network, such as the Internet. Various modifications and additions can be made to the described exemplary embodiments without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of this invention is intended to embrace all such alternatives, modifications, and variations that fall within the scope of the claims, together with all equivalents thereof.

[0064] 2A-2B are schematic diagrams illustrating an electroporation ablation catheter 200 that can be used for electroporation ablation, including irreversible electroporation ablation, in accordance with an embodiment of the presently disclosed subject matter. FIG. 2A illustrates the catheter 200 in a first state, and FIG. 2B illustrates the catheter 200 in a second state. The catheter 200 may have two or more states, which may be configurable or controllable by a user or automatically configurable by an electroporation system during a procedure. The catheter 200 includes a catheter shaft 202 and a plurality of catheter splines 204 connected to the catheter shaft 202 at a distal end 206 of the catheter shaft 202. The catheter 200 may further include an inner shaft 203 disposed within the catheter shaft 202 and extending distally from the distal end 206 of the catheter shaft 202. As can be appreciated, the catheter shaft 202 is coupled at its proximal end to a handle assembly (not shown) configured to be manipulated by a user during an electroporation ablation procedure. As further shown, the catheter 200 includes a distal electrode assembly 250 that extends from the distal end 206 of the catheter shaft 202 .

[0065] In embodiments, the electrode assembly 250 includes a plurality of energy-delivery electrodes (e.g., ablation electrodes) 225, and the electrode assembly 250 is configured to be selectively operable in a first state and a second state. In some cases, in the first state, the electrode assembly 250 is configured to deliver ablation energy to form a circumferential ablation lesion having a particular diameter.

[0066] In some embodiments, the electrode assembly 250 includes an inner shaft 203 that extends from and is adapted to retract into the catheter shaft 202. In some cases, the electrode assembly 250 includes a plurality of splines 204 connected to the inner shaft 203 at a distal end 211 of the inner shaft 203. In some cases, the electrode assembly 250 further includes a central shaft 203a having a proximal end 211a (overlapping with the distal end 211 of the inner shaft 203) and a distal end 212. In some cases, the plurality of splines 204 are connected to the distal end 212 of the central shaft 203a. In embodiments, the electrodes 225 include a plurality of first electrodes 208 and a plurality of second electrodes 210 arranged on the plurality of splines 204. In one example, the plurality of second electrodes 210 are positioned proximate the distal end 212 of the central shaft 203a, and the plurality of first electrodes 208 are positioned proximate the proximal end 211a of the central shaft 203a.

[0067] In some cases, when operating in the first state, the inner shaft 203 and the central shaft 203a extend from the catheter shaft 202, for example, as shown in Figure 2A. In some cases, in the first state, both the plurality of first electrodes 208 and the plurality of second electrodes 210 are selectively energized and activated to form relatively large diameter circumferential ablation lesions, for example, for use in pulmonary vein isolation (PVI) procedures.

[0068] In some embodiments, when operating in the second state, the inner shaft 203 and the central shaft 203a are at least partially retracted into the catheter shaft 202 such that all or a portion of the plurality of first electrodes 208 are retracted into the catheter shaft 202, for example, as illustrated in FIG. 2B. In some cases, in the second state, the plurality of first electrodes 208 are deactivated (e.g., by electrically disconnecting the first electrodes 208 from any pulse generator circuitry) and the plurality of second electrodes 210 are activated and used to create local ablation lesions via electroporation.

[0069] Ablation catheter 200 has a longitudinal axis 222. As used herein, a longitudinal axis refers to a line passing through the center of gravity of a cross-section of an object. In embodiments, multiple splines 204 form cavity 224. Multiple splines 204 form cavity 224a in a first state and cavity 224b in a second state. In embodiments, cavity 224a has a larger volume than cavity 224b. In some embodiments, in the first state, the largest cross-sectional area of ​​cavity 224a generally perpendicular to longitudinal axis 222 has a diameter d1. In some embodiments, in the second state, the largest cross-sectional area of ​​cavity 224b generally perpendicular to longitudinal axis 222 has a diameter d2. In some cases, diameter d1 is larger than diameter d2.

[0070] In some examples, diameter d1 is within the range of 20 millimeters to 35 millimeters. In particular examples, diameter d1 is within the range of 10 millimeters to 25 millimeters. In some examples, diameter d2 is within the range of 5 millimeters to 16 millimeters. In some examples, diameter d2 is within the range of 5 millimeters to 16 millimeters. In one example, diameter d1 is 30% to 100% larger than diameter d2. In one example, diameter d1 is at least 30% larger than diameter d2. In one example, diameter d1 is at least 20% larger than diameter d2. In one example, diameter d1 is at least 100% larger than diameter d2 (i.e., at least twice as large as diameter d2). In one example, diameter d1 is at least 150% larger than diameter d2 (i.e., at least 2.5 times as large as diameter d2).

[0071] In some cases, the first group of electrodes 208 are positioned around or proximate the circumference of the plurality of splines 204, and the second group of electrodes 210 are positioned proximate the distal end 212 of the catheter 200. In some cases, the first group of electrodes 208 are referred to as proximal electrodes, and the second group of electrodes 210 are referred to as distal electrodes, with the distal electrodes 210 being positioned closer to the distal end 212 of the electroporation ablation catheter 200 than the proximal electrodes 208. In some implementations, the electrodes 225 can include a thin film of conductive or optical ink. The ink can be polymer-based. The ink can additionally include materials such as carbon and / or graphite in combination with a conductive material or metal oxide coating, which can lower the impedance on the electrode and increase the signal-to-noise ratio. The electrodes can include biocompatible, low-resistivity metals such as silver, silver flake, gold, and platinum, which are additionally radiopaque.

[0072] Each electrode of the first group of electrodes 208 and each electrode of the second group of electrodes 210 is configured to conduct electricity and to be operably connected to a controller (e.g., controller 90 of FIG. 1 ) and an ablation energy generator (e.g., electroporation generator 130 of FIG. 1 ). In embodiments, one or more of the plurality of electrodes of the first group of electrodes 208 and the second group of electrodes 210 include a flex circuit. In some cases, the plurality of first electrodes 208 are individually controllable. In some cases, the plurality of second electrodes are individually controllable. In some cases, all or a portion of the plurality of first electrodes 208 are deactivated in the second state. In some cases, a portion of the plurality of second electrodes 210 are deactivated in the second state.

[0073] The electrodes of the first group of electrodes 208 are spaced apart from the electrodes of the second group of electrodes 210. The first group of electrodes 208 includes electrodes 208a-208f, and the second group of electrodes 210 includes electrodes 210a-210f. Additionally, the electrodes of the first group of electrodes 208, such as electrodes 208a-208f, are spaced apart from one another, and the electrodes of the second group of electrodes 210, such as electrodes 210a-210f, are spaced apart from one another.

[0074] The spatial relationship and orientation of the electrodes of the first group of electrodes 208 and the second group of electrodes 210 relative to other electrodes on the same catheter 200 are known or can be determined. In embodiments, the spatial relationship and orientation of the electrodes of the first group of electrodes 208 and the second group of electrodes 210 relative to other electrodes on the same catheter 200 are constant once the catheter is deployed. In embodiments, the spatial relationship and orientation of the electrodes of the first group of electrodes 208 and the second group of electrodes 210 relative to other electrodes on the same catheter 200 are not constant. In some examples, the spatial relationship and orientation of the electrodes of the first group of electrodes 208 and the second group of electrodes 210 relative to other electrodes on the same catheter 200 are predictable when the catheter is deployed.

[0075] With respect to the electric field, in embodiments, each electrode in the first group of electrodes 208 and each electrode in the second group of electrodes 210 may be selected to be an anode or a cathode, thereby establishing an electric field between any two or more of the electrodes in the first group of electrodes 208 and the second group of electrodes 210. Also, in embodiments, each electrode in the first group of electrodes 208 and each electrode in the second group of electrodes 210 may be selected to be biphasic, thereby causing the electrodes to switch or alternate between an anode and a cathode. Also, in embodiments, groups of electrodes in the first group of electrodes 208 and groups of electrodes in the second group of electrodes 210 may be selected to be anodic or cathodic or biphasic, thereby establishing an electric field between any two or more groups of electrodes in the first group of electrodes 208 and the second group of electrodes 210.

[0076] In embodiments, the electrodes of the first group of electrodes 208 and the second group of electrodes 210 may be selected to be biphasic electrodes, such that during pulse trains including biphasic pulse trains, the selected electrodes switch or alternate between anode and cathode, rather than being monophasic, with one electrode always being the anode and the other always being the cathode. In some cases, the electrodes of the first group of electrodes 208 and the second group of electrodes 210 may form an electric field with an electrode(s) of another catheter. In such cases, the electrodes of the first group of electrodes 208 and the second group of electrodes 210 may be the anode of the electric field or the cathode of the electric field.

[0077] Furthermore, while, as described herein, electrodes are selected to be one of anodes and cathodes, it should be understood without further elaboration that throughout this disclosure, electrodes may be selected to be biphasic, such that they switch or alternate between anodes and cathodes. In some cases, one or more of the electrodes in the first group of electrodes 208 are selected to be cathodes, and one or more of the electrodes in the second group of electrodes 210 are selected to be anodes. In embodiments, one or more of the electrodes in the first group of electrodes 208 may be selected as cathodes, and another one or more of the electrodes in the first group of electrodes 208 may be selected as anodes. In addition, one or more of the electrodes in the second group of electrodes 210 may be selected as cathodes, and another one or more of the electrodes in the second group of electrodes 210 may be selected as anodes.

[0078] In some examples, the first group of electrodes 208 are positioned proximal to the maximum circumference (d1) of the catheter splines 204, and the second group of electrodes 210 are positioned distal to the maximum circumference of the catheter splines 204. In some embodiments, additional electrodes (e.g., mapping electrodes) may be added to each of the multiple splines 204.

[0079] In embodiments, ablation catheter 200 includes a navigation sensor 220 configured to collect sensor data related to the position of the electrode assembly, the navigation sensor including a first sensor 220a disposed on one of one or more splines 204. The position of the electrode assembly is related to the position of the navigation sensor. In some embodiments, ablation catheter 200 further includes a central shaft 203a disposed within a cavity formed by the one or more splines, and navigation sensor 220 includes a second sensor 220b disposed on central shaft 216. In some embodiments, electroporation catheter 105 further includes a catheter shaft 202, the electrode assembly extending from catheter shaft 202 at distal end 206, and navigation sensor 220 includes a catheter shaft sensor 202c disposed on catheter shaft 220.

[0080] In some embodiments, navigation sensor 220a and second navigation sensor 220b are embedded in or integrated with the walls of spline 204 and central shaft 203a. In some embodiments, navigation sensor 220 further includes third navigation sensor 220c in addition to first navigation sensor 220a and second navigation sensor 220b. In some examples, third navigation sensor 220c is disposed on catheter shaft 202 (e.g., on the surface of catheter shaft 202, within catheter shaft 202). In particular examples, third navigation sensor 220c, referred to as a catheter shaft sensor, is disposed at distal end 211 of catheter shaft 202. In some examples, third navigation sensor 220c may be disposed on one of the splines. In particular examples, navigation sensor 220 includes sensors (e.g., an inductive sensor, an MR sensor, a 5-DOF sensor, a 6-DOF sensor) disposed on various components of electroporation ablation catheter 200.

[0081] In an embodiment, navigation sensors 220 include a navigation sensor 220a located on one of the splines and another navigation sensor (e.g., a third navigation sensor 220c) located on catheter shaft 202. In an embodiment, navigation sensor 220a is a magnetoresistive sensor and second navigation sensor 220b is an inductive sensor.

[0082] In some embodiments, navigation sensors 220 include a micro 6-DOF sensor. In some embodiments, navigation sensors 220 include an inductive sensor. In some embodiments, navigation sensors include one or more 5-DOF and / or 6-DOF sensors.

[0083] 3A-3C are schematic diagrams illustrating an ablation catheter 300 in various states that can be used for electroporation ablation, including irreversible electroporation ablation, according to an embodiment of the presently disclosed subject matter.

[0084] FIG. 3A shows a catheter 300A in a first state, or what is referred to as a first mode of operation. In some embodiments, the catheter 300A includes an electrode assembly 350A. The electrode assembly 350A has a first shape, referred to as a basket shape in FIG. 3A . The catheter 300A includes a catheter shaft 302. The electrode assembly includes a plurality of splines 304 connected to the catheter shaft 302 at a distal end 306 of the catheter shaft 302. The catheter splines 304 include a plurality of electrodes 310 disposed thereon. Each electrode of the plurality of electrodes 310 is configured to conduct electricity and to be operably connected to an electroporation generator (e.g., the electroporation generator 130 of FIG. 1 ). In embodiments, one or more electrodes of the plurality of electrodes 310 include a metal.

[0085] The electrode assembly 350A has a proximal end 316 near the distal end 306 of the catheter shaft 302 and a distal end 314 further away from the distal end 306 of the catheter shaft 302. As shown, the catheter shaft 302 defines a longitudinal axis 322, and a plurality of splines 304 are arranged in a curved shape between the distal end 314 and the proximal end 316. In embodiments, in the first state, each spline 304 of the electrode assembly 350A is arranged as a curve without a turning point. In some examples, each spline 304 has a degree of curvature less than a predetermined degree. For example, each spline 304 has a curvature of less than 45°.

[0086] 3B-3C show catheter 300B in a second state, referred to as a second operating mode, from an end view, and FIG. 3C shows catheter 300C in the second state from a side view. In embodiments, each of the plurality of splines 304 includes one or more electrodes 310 disposed thereon. For example, as shown, spline 304a includes four electrodes. In some embodiments, each of the plurality of splines 304 may include five or more electrodes. In some embodiments, each of the plurality of splines 304 may include fewer than four electrodes. As will be appreciated by those skilled in the art, the number of electrodes on each spline, including the spacing between each electrode, can be adjusted. The catheter shaft may further include a cap 326. In embodiments, cap 326 is atraumatic to reduce trauma to tissue.

[0087] Each of the plurality of splines 304 as shown has a similar size, shape, and spacing between adjacent electrodes 310 on the spline 304. In other embodiments, the size, shape, and spacing between adjacent electrodes 310 on the spline 304 may be different. In some embodiments, the thickness and length of each of the plurality of splines 304 may vary based on the number of electrodes on the spline 304 and the spacing between each electrode. The splines 304 may be made from similar or different materials and may have different thicknesses or lengths.

[0088] As shown, each of the plurality of splines 304 is disposed in a petal-shaped curve 332 in a second state in which the distal end 314 of the electrode assembly 350 is adjacent to the proximal end 316 of the electrode assembly 350. Each of the plurality of splines 304 may pass through the distal end 306 of the catheter shaft 302 and be coupled to the catheter shaft 302 within the catheter shaft lumen. A distal end of each of the plurality of splines 304 may be coupled to the cap 326 of the catheter 300. In some embodiments, one or more of the curves 332 are electrically isolated. As shown, the petal-shaped curve 332 includes a turn-back point.

[0089] In some embodiments, catheter 300B includes electrode assembly 350B arranged in a second shape, or what is referred to as a flower shape, as shown in FIG. 3B. In some embodiments, catheter 300C includes electrode assembly 350C arranged in a second shape, as shown in FIG. 3C. As shown, each of the plurality of splines 304 may include a flexible curvature such that it can rotate or twist to form a petal-like curve 332. The minimum radius of curvature of the splines in the petal-like configuration may be in the range of about 7 mm to about 25 mm. For example, splines 304 may form electrode assembly 350 in a distal portion of catheter 300 and be configured to transform between a first shape in which the set of splines is arranged generally parallel to the longitudinal axis of catheter 300 and a second shape in which the set of splines rotates or twists about the longitudinal axis of catheter 300 to bend generally away from the longitudinal axis of catheter 300. In the first configuration, each spline of the spline set 304 can lie in a plane with the longitudinal axis 322. In the second configuration, each spline of the spline set 304 can be biased away from the longitudinal axis 322 to form a petal-like curve 332 disposed generally perpendicular to the longitudinal axis 322. In this manner, the spline set 304 twists, bends, and is biased away from the longitudinal axis 322 of the catheter 300, thus allowing the spline 304 to more easily conform to the geometry of the intracardiac space, particularly adjacent the pulmonary ostium opening. The second shape can resemble the shape of a flower, for example, from an end view, as shown in FIG. 3B. In some embodiments, each spline of the spline set in the second configuration can twist and bend to form a petal-like curve when viewed from the front, with the angle of curvature between the proximal and distal ends of the curve approaching 180 degrees.

[0090] The spline set may be further configured to transform from a second shape to a third shape, and the spline set 304 may be apposed to (e.g., contacting or positioned adjacent to) a target tissue, such as tissue surrounding a pulmonary vein ostium. The splines 304 form a shape generally parallel to the longitudinal axis 322 of the catheter shaft 302 when undeployed and may be wound (e.g., spirally, twisted) around an axis (not shown) parallel to the longitudinal axis 322 when fully deployed, forming any intermediate shape (such as a cage or barrel) between the various shapes. In some cases, when operating in the first state, the inner shaft 303 including the central shaft 303a is extended from the catheter shaft 302, as shown, for example, in FIG. 3A. In some cases, when operating in the second state, the inner shaft 303 is retracted within the catheter shaft 302, as shown, for example, in FIGS. 3B-3C.

[0091] In embodiments, the ablation catheter 300 includes a navigation sensor 320 configured to collect sensor data related to the position of the electrode assembly. In certain embodiments, the navigation sensor 320 is configured to collect sensor data related to the position of the electrode assembly when a location identification field generator (e.g., location identification field generator 80 of FIG. 1 ) is active. In some examples, the navigation sensor includes a first navigation sensor 320 a disposed on one of the one or more splines 304. The position of the electrode assembly is associated with the position of the navigation sensor. In some embodiments, the ablation catheter 300 further includes a central shaft 303 a disposed within a cavity 324 formed by the one or more splines 304, and the navigation sensor 320 includes a second sensor 320 b disposed on the central shaft 303 a. In some embodiments, the ablation catheter further includes a catheter shaft 302, the electrode assembly extending from the catheter shaft 302 at the distal end 306, and the navigation sensor 320 includes a catheter shaft sensor 320 c disposed on the catheter shaft 302.

[0092] In some embodiments, navigation sensor 320a and second navigation sensor 320b are embedded in the walls of the splines. In some embodiments, navigation sensor 320 further includes a third navigation sensor 320c in addition to first navigation sensor 320a and second navigation sensor 320b. In some examples, third navigation sensor 320c is disposed on catheter shaft 302. In particular examples, third navigation sensor 320c, referred to as a catheter shaft sensor, is disposed at the distal end 306 of catheter shaft 302. In some examples, third navigation sensor 320c may be disposed on one of the splines. In particular examples, navigation sensor 320 includes sensors (e.g., an inductive sensor, an MR sensor, a 5-DOF sensor, a 6-DOF sensor) disposed on various components of electroporation ablation catheter 200.

[0093] In an embodiment, navigation sensor 320a is located on one of the splines and another navigation sensor is located on catheter shaft 302. In an embodiment, navigation sensor 320a is a magnetoresistive sensor and navigation sensor 320b is an inductive sensor.

[0094] In some embodiments, navigation sensors 320 include a micro 6-DOF sensor. In some embodiments, navigation sensors 320 include an inductive sensor. In some embodiments, navigation sensors include one or more 5-DOF and / or 6-DOF sensors.

[0095] 4A-4D are schematic diagrams illustrating an embodiment of an ablation catheter 400 that can be used for electroporation ablation, including irreversible electroporation ablation, in accordance with an embodiment of the presently disclosed subject matter.

[0096] Figure 4A shows catheter 400A in a first state, or what is referred to as the non-deployed state. Figure 4B shows catheter 400B in a second state, or what is referred to as Deployment State 1. Figure 4C shows catheter 400C in a third state, or what is referred to as Deployment State 2. Figure 4D shows catheter 400D in a fourth state, or what is referred to as Deployment State 3.

[0097] As shown, the catheter 400 includes an electrode assembly 450 having one or more splines 404. In embodiments, the one or more splines 404 are flat splines. As used herein, a flat spline has a thickness that is less than the width of the spline. In one example, the thickness of the flat spline is less than 75% of the width of the spline. In one example, the thickness of the flat spline is less than 60% of the width of the spline. In one example, the thickness of the flat spline is less than 50% of the width of the spline. In one example, the thickness of the flat spline is less than 25% of the width of the spline. In one example, the thickness of the flat spline is less than 10% of the width of the spline. In some examples, catheters with flat splines have better flexibility, but flat splines present challenges in accommodating certain components (e.g., sensors). In embodiments, the electrode assembly includes one or more electrodes 410, at least a portion of which are disposed on one or more splines, the one or more electrodes configured to generate an electric field at the target tissue in response to a plurality of electrical pulse sequences. In several embodiments, the catheter 400 further includes a navigation sensor 420 configured to collect sensor data related to the position of the electrode assembly, the navigation sensor 420 including a first sensor 420a disposed on one of the one or more splines.

[0098] The catheter 400 has a central shaft 403a disposed within a cavity 424 formed by one or more splines 404. In some embodiments, the navigational sensor includes a second sensor 420b disposed on the central shaft 403a. In certain embodiments, the navigational sensor disposed on the central shaft 403a includes a micro 6-DOF sensor.

[0099] The catheter 400 also has a catheter shaft 402 from which an electrode assembly 450 extends. In embodiments, the navigational sensor includes a catheter shaft sensor 420c disposed on the catheter shaft 402. In some embodiments, the navigational sensor may include an inductive sensor. In particular embodiments, the navigational sensor may include two 5-DOF sensors. As will be understood by those skilled in the art, there is no definitive correlation between the number of degrees of freedom ("DOF") a sensor has and the type of sensor (e.g., inductive or magnetoresistive).

[0100] Each spline of the one or more splines 404 includes a first portion 430, a second portion 432, and a bent portion 434 connecting the first portion 430 and the second portion 432. As shown, when the catheter 400 is in various deployment states (e.g., deployment states 1, 2, and 3), the bent portion 434 bends such that the first portion 430 and the second portion 432 move closer or farther apart while remaining substantially straight compared to the bent portion 434. In some embodiments, the first portion 430 and / or the second portion 432 have a radius that is smaller than the radius of the bent portion 434.

[0101] In an embodiment, the navigation sensor 420 may be disposed on the first portion 430 or the second portion 432. Because the first portion 430 and the second portion 432 remain substantially straight in one or more deployed states, the sensor exerts less tension on the spline in each of the deployed states. During treatment in each of the deployed states, some potential problems caused by excessive tension include the spline potentially breaking at the tip attachment point 436 or kinking the wire within the spline. Reducing the tension generated by locating the navigation sensor on a spline portion that remains substantially straight helps minimize the occurrence of these problems. Additionally, locating the sensor on a spline portion that remains substantially straight (e.g., portions 430 and 432) exerts less stress on the sensor, thereby reducing the likelihood of the sensor breaking and / or causing less change in the sensor's electromagnetic characteristics. Changes in the sensor's electromagnetic characteristics can lead to less accurate localization.

[0102] As described above, the first sensor 420a may be located on one of the one or more splines. In embodiments, as described in more detail below, the navigation sensor 420, or what is referred to as a set of navigation sensors, may be embedded in the wall of one or more splines. Sensors embedded in the wall are sometimes referred to as air-core inductive sensors because of the space in the center of the coil. In embodiments, the navigation sensors may include a third sensor located on the catheter shaft 402. In other embodiments, the third sensor may be located on one or more splines.

[0103] In an embodiment, a first sensor may be located on one of the splines 404 and a second sensor may be located on the catheter shaft 402. The first sensor 420a may be a magnetoresistive sensor and the second sensor 420b may be an inductive sensor.

[0104] 5A-5D are schematic diagrams illustrating an inductive sensor and an air-core inductive sensor, respectively, according to embodiments of the disclosed subject matter. FIG. 5A illustrates an inductive sensor 52, and FIG. 5B illustrates two cross-sectional views of the inductive sensor 52 disposed on a support structure 4 (e.g., a spline, a central shaft, a catheter shaft). As shown in FIGS. 5A-5B, the inductive sensor 52 includes multiple turns of conductive wire. The coils are tightly packed to reduce the size of the sensor 52, leaving little space within the formed sensor. Due to its relatively small size, the sensor 52 can fit within the support structure 4 and be disposed within the support structure 4. In some examples, the sensor 52 is a solid-core inductive sensor.

[0105] FIG. 5C illustrates a sensor 55, and FIG. 5D illustrates two cross-sectional views of the sensor 55 disposed on or integrated with the support structure 4 (e.g., a spline, a central shaft, or a catheter shaft). As shown in FIGS. 5C-5D, the sensor 55 is an air-core inductive magnetic sensor with multiple turns of conductive wire. The coil forms a circle at its center with a radius approximately the same as the central opening of the support structure 4. In one example, the coil of conductive wire of the sensor 55 is embedded in the wall of the spline. As shown in the side view, the air-core inductive magnetic sensor 55 with conductive wire is disposed circumferentially around the cavity of the support structure 4. In some examples, the sensor 55 may be disposed on a catheter shaft (e.g., the inner shaft 203 and the catheter shaft 202 in FIG. 2). This configuration advantageously maintains the patency of the spline opening to accommodate the passage of additional probes or devices. In some implementations, the sensor 55 allows one or more conductive wires to pass through its air-core.

[0106] The internal payload space of a device may be partially obstructed by a sensor, such as sensor 52 of Figure 5A. An alternative sensor design to an air-core sensor (e.g., air-core inductive sensor 55) can reduce the obstruction of the payload space of a device where the air-core sensor leaves the center open, thus allowing more payload to be incorporated into the device.

[0107] FIG. 6 is a schematic diagram illustrating a catheter shaft according to an embodiment of the presently disclosed subject matter. As shown, the catheter shaft 602 includes a navigation sensor 620 located on the distal end 606 of the catheter shaft 602. The distal end 606 of the catheter shaft 602 is connected to an electrode assembly as shown in the previous figure. In embodiments, the navigation sensor 620 may be a 6-DOF sensor. In embodiments, the navigation sensor 620 may be a magnetoresistive sensor. In embodiments, the navigation sensor 620 may be an inductive sensor. In embodiments, the catheter shaft 602 may include a pull ring 608. In some examples, the catheter shaft 602 may include an electrode 610. The electrode 610 may be a tracking electrode for injecting a tracking current. In some embodiments, the electrode 610 may be a sensing electrode configured to collect an electrical signal when a tracking current is injected during operation.

[0108] In embodiments, navigational sensor 620 may be the only sensor located on catheter shaft 602. In embodiments, navigational sensor 620 may include sensors in addition to and configured to cooperate with other navigational sensors located on an electrode assembly (not shown).

[0109] In an embodiment, electrode 610 is a tracking electrode, and the spatial relationship between electrode 610 on the catheter and navigation sensor 620 is known. The tracking electrode injects a current to generate a local electric field, and the corresponding signal measured by an electrode of an electrode assembly (e.g., electrode assembly 350 of FIG. 3 or electrode assembly 450 of FIG. 4) is used to detect the shape of the electrode assembly relative to tracking electrode 610 and navigation sensor 620, thereby determining the global position and orientation of each electrode of the assembly. In one embodiment, electrode 610 is a sensing electrode with a known position relative to navigation sensor 620, and is used to measure electrical signals that are used to generate a field map from the current injection of other tracking electrodes (e.g., tracking electrodes located on the patient's skin). The generated field map is then used to track the positions of the electrodes of the electrode assembly.

[0110] 7A-7B are schematic diagrams illustrating a system or electroporation device 705 including an ablation catheter 700 with a deployed electrode assembly and one or more tracking electrodes, according to an embodiment of the presently disclosed subject matter.

[0111] As shown, an electrode assembly 750 of an ablation catheter 700 is positioned adjacent to target tissue located in a patient's heart chamber 770. The electrode assembly 750 includes a plurality of splines 704 and a plurality of electrodes 710. At least one of the plurality of electrodes 710 is disposed on the plurality of splines 704. The electrode assembly 750 can be in a first state, as shown in FIG. 7A, or a second state, as shown in FIG. 7B. In an embodiment, the catheter 700 includes a longitudinal axis 722 defined by a catheter shaft 702, and the electrode assembly 750 extends from the catheter shaft 702. In an embodiment, the two or more electrodes 710 form a plane that is generally perpendicular to the longitudinal axis 722.

[0112] In embodiments, a system or electroporation device 705 for electroporation ablation may include an ablation catheter 700 including an electrode assembly 750. In embodiments, a system or electroporation device 705 for electroporation ablation may include one or more tracking electrodes 760, 762, 764 configured to deliver electrical current. As shown, tracking electrode 760 may be positioned in a patient's heart chamber 770 (e.g., an electrode on a catheter deployed in heart chamber 770). In some embodiments, tracking electrode 762 may be positioned on a patient's body surface (not shown) (e.g., on the patient's back or chest). In some embodiments, tracking electrode 764 may be positioned on the catheter shaft. In some embodiments, one of electrodes 710 may be used as a tracking electrode for injecting electrical current.

[0113] In an embodiment, the system for electroporation ablation 705 includes one or more sensors (not shown) configured to measure an electrical signal of at least one of the one or more electrodes 710 when an electrical current is delivered. In an embodiment, the system for electroporation ablation further includes one or more processors (not shown) configured to receive the measured electrical signal, estimate at least one electrode position corresponding to at least one of the one or more electrodes 710 based on the measured electrical signal, and update the at least one electrode position corresponding to at least one of the one or more electrodes 710 based on a geometric model of the ablation catheter 700.

[0114] In some embodiments, the system 705 is further configured to access a field map and estimate, based on the measured electrical signal and the field map, at least one electrode position corresponding to at least one of the one or more electrodes 710. In an embodiment, the field map is generated by using a mapping catheter.

[0115] In embodiments, ablation catheter 700 may include a navigation sensor or set of navigation sensors (e.g., the navigation sensors shown in FIGS. 2-4), and system 705 may be configured to generate a field map based on signals collected by the navigation sensors and sensing electrodes having a fixed and known relationship to the navigation sensors. In embodiments, the navigation sensors may be 5-DOF sensors. In embodiments, the navigation sensors may be 6-DOF sensors. In embodiments, the navigation sensors may be inductive sensors. In one embodiment, the sensing electrodes are configured to measure the electrical potential of the current being injected.

[0116] In some embodiments, system 705 uses one or more geometric models to determine and / or refine the position (also referred to as location) of one or more electrodes of electrode assembly 701 and / or electrode assembly 701 after an initial estimation of the position. In embodiments, system 705 is configured to receive measured electrical signals when tracking electrodes (e.g., tracking electrode 760, tracking electrode 762) are injecting current, estimate at least one electrode position corresponding to at least one of the one or more ablation electrodes based on the measured electrical signals, and update the at least one electrode position or electrode assembly position corresponding to at least one of the one or more ablation electrodes based on the geometric model of ablation catheter 700. In certain embodiments, system 705 is configured to access multiple geometric models, each corresponding to a state of electroporation catheter 700 and a predetermined contour of electrode assembly 701 of electroporation catheter 700.

[0117] In certain embodiments, the geometric model includes rules applicable to catheters having the shape of a spline (e.g., a deformable spline). In some examples, the geometric model includes rules for radius ranges that specify, for example, the curvature of paths between electrodes. In certain examples, the geometric model includes rules applicable that are expressed as a function of the number of electrodes (e.g., the path between electrode 1 and electrode 2 may have a different radius range than the path between electrode 2 and electrode 3).

[0118] In embodiments, the radius range may be between adjacent electrodes. In some embodiments, the radius range may be between the endpoints of each spline. In certain embodiments, the geometric model includes one or more rules that describe the tangent conditions and / or volume of the cavity formed by the multiple splines. In some embodiments, the geometric model includes a radius range from the tip of the catheter 700 to an adjacent electrode (e.g., from the distal end 314 to the first electrode 310a as shown in FIG. 3A), e.g., the radius range exhibits a concave shape. In some embodiments, the radius range may be between two adjacent electrodes (e.g., from the first electrode 310a to the second electrode 310b as shown in FIG. 3A), and in the deployed state, the radius range exhibits a convex shape. In some embodiments, the radius range may be between the first electrode (e.g., the electrode on the spline closest to the tip 716 of the catheter 700) and the last electrode (e.g., another electrode on the spline closest to the proximal end 715 of the catheter 700), and the shape would substantially resemble a polynomial fit.

[0119] In some embodiments of the catheter 700 that include flexible (e.g., bendable) splines, the shape of each spline may not be identical to one another. The radius of the splines may change due to deformation of the splines upon tissue contact. Thus, the geometric model includes rules (e.g., radius ranges) for each spline. When spline deformation occurs upon tissue contact, the system 705 may be automatically and / or manually controlled by operations that adjust the position of the electrode assembly 701 to account for deformation of one or more splines that results in deformation of the electrode assembly 701.

[0120] In embodiments, the geometric model may include one or more rules for electrodes on splines of the same order (e.g., electrode 1 on splines A, B, C, electrode 2 on splines A, B, C, electrode 3 on splines A, B, C, and electrode 4 on splines A, B, C). In some examples, the geometric model may include rules for electrodes on splines of the same order to be on the same plane that is approximately perpendicular to the longitudinal axis 722, or referred to as the same level of latitude. In certain embodiments, the system 705 is configured to apply the geometric model and adjust the electrode positions (e.g., snap electrodes from various splines to be at the same level of latitude). In embodiments, the system 705 is configured to use the electrode positions to determine the shape of the electrode assembly and adjust the electrode positions according to a template (e.g., a deployed state template).

[0121] In embodiments, the geometric model includes rules (e.g., constraints) including a predetermined relative position of the tip 716 of the catheter 700 with one or more electrodes on the spline, for example, to avoid the tip 716 from penetrating or damaging tissue during treatment. In embodiments where no electrodes are located at the tip of the catheter, the position of the tip may be determined based on one or more rules (e.g., constraints) to provide an updated and / or refined position, rather than being determined by directly locating the electrodes.

[0122] The geometric model may include one or more constraints regarding one or more relative electrode positions of one or more ablation electrodes. In embodiments, the geometric model may include relative electrode positions of two ablation electrodes disposed on one spline of the one or more splines. In embodiments, the geometric model includes relative electrode positions of two or more ablation electrodes, each ablation electrode of the two or more ablation electrodes disposed on a respective spline of the one or more splines.

[0123] In an embodiment, the geometric model includes a first predetermined radius range for a first portion of one of the one or more splines 704 (e.g., portion 430 in FIG. 4 ). In an embodiment, the geometric model includes a second predetermined radius range for a second portion of one of the one or more splines 704 (e.g., bent portion 434 in FIG. 4 ), the second portion of one of the one or more splines being different from the first portion of one of the one or more splines 704, and the second predetermined radius range being different from the first predetermined radius range.

[0124] In some embodiments, a system 705 for electroporation ablation includes a deployment sensor (e.g., deployment sensor 106 of FIG. 1) configured to collect data related to a deployment state. In embodiments, the system 705 is configured to receive the collected data related to the deployment state and update or select a geometric model based on the collected data. In some examples, the system 705 is configured to update the geometric model by selecting a different geometric model. In particular examples, the system 705 is configured to update the geometric model by selecting a different geometric model corresponding to the deployment state. In embodiments, the deployment sensor may be located on a handle (e.g., handle 105a shown in FIG. 1) or within an electrode assembly (e.g., the electrode assemblies illustrated in FIGS. 2-4). The handle 105a may include a slider to assist an operator in controlling the shape of the electrode assembly. For example, as the slider is pulled, one or more splines on the electrode assembly are increasingly bent, ultimately resulting in a petal-like shape (e.g., the electrode assemblies illustrated in FIGS. 2B-2C). As the slider is pushed, one or more splines on the electrode assembly become less curved, returning the one or more splines to a substantially straight or relatively less curved state. In some examples, the tip of the electrode assembly may twist about the longitudinal axis (e.g., axis 322 in FIG. 3). In certain embodiments, the collected data can be used to determine the degree of rotation of the tip of the electrode assembly, and a deployment state can be determined based on the collected data to update the geometric model.

[0125] 8 is a flowchart diagram illustrating a process 800 for facilitating ablation by irreversible electroporation, according to an embodiment of the presently disclosed subject matter. While the method is described in connection with the catheters discussed previously herein, any suitable electroporation catheter may be used in the method. Aspects of the method embodiments may be performed, for example, by an electrophysiology system or controller (e.g., system 50 of FIG. 1 , controller 90 of FIG. 1 ). One or more steps of the method are optional and / or may be modified by one or more steps of other embodiments described herein. Additionally, one or more steps of other embodiments described herein may be added to the method.

[0126] At 802, process 800 includes deploying an ablation catheter proximate to a target tissue. The ablation catheter may include an electrode assembly and a navigation sensor. In embodiments, the electrode assembly includes a plurality of splines and a plurality of ablation electrodes, at least one of the plurality of ablation electrodes being disposed on the plurality of splines. In embodiments, the navigation sensor is disposed on or integrated with at least one of the plurality of splines.

[0127] At 804, process 800 includes collecting sensor data from navigation sensors. At 806, process 800 includes determining a position of the electrode assembly based on the collected data. In an embodiment, the state of the electrode assembly has a plurality of deployment states, and when the electrode assembly is in a first state of the plurality of deployment states, the electrode assembly is in a first shape, and when the electrode assembly is in a second state of the plurality of deployment states, the electrode assembly is in a second shape.

[0128] At 808, process 800 may optionally include determining a rotation angle of the electrode assembly based on the collected sensor data. In some embodiments, the navigation sensor may include two 5-DOF sensors. In some embodiments, the navigation sensor may include one 6-DOF sensor.

[0129] 9A-9E are flow and system diagrams illustrating a process for facilitating ablation by irreversible electroporation according to an embodiment of the presently disclosed subject matter. While the method is described in connection with the catheters discussed previously herein, any suitable electroporation catheter may be used in the method. Aspects of the method embodiments may be performed, for example, by an electrophysiology system or controller (e.g., system 50 of FIG. 1 , controller 90 of FIG. 1 ). One or more steps of the process are optional and / or may be modified by one or more steps of other embodiments described herein. Additionally, one or more steps of other embodiments described herein may be added to the exemplary process.

[0130] 9A , at 902A, process 900A may include deploying an ablation catheter adjacent to a target tissue. In an embodiment, the ablation catheter includes an electrode assembly, the electrode assembly including a plurality of splines and a plurality of ablation electrodes, at least one of the plurality of ablation electrodes disposed on the plurality of splines. At 904A, process 900A may include deploying one or more tracking electrodes at one or more target locations.

[0131] At 906A, process 900 may include injecting a current through one or more tracking electrodes. At 908A, process 900A may include measuring an electrical signal through at least one of the one or more ablations.

[0132] At 910A, process 900A may include estimating an electrode position corresponding to one of the one or more ablation electrodes based on the measured electrical signal. Various data sources may be used to estimate the position of each individual electrode. For example, data sources may include electrical potential measurements obtained from a subject's catheter in response to current injected by an electrode on the body surface.

[0133] In embodiments, the data sources may include electrical potential measurements obtained from the target catheter in response to currents driven by separate electrodes on the target catheter. In some embodiments, the data sources may include electrical potential measurements obtained from a combination of currents injected into both the body surface and local electrodes on the target catheter. In some embodiments, the data sources may include electrical potential measurements obtained from additional sensors on the ablation catheter (e.g., the navigation sensors of FIGS. 2-6).

[0134] Once individual electrode positions are estimated, tracking each electrode independently can amplify errors in any tracking algorithm. To reduce this error, rules regarding inter-electrode distance and the trajectory of the lines drawn to connect the electrodes can be applied when displaying the catheter on the user interface. These rules adjust the individual 3D positions of the electrodes within the mapping system. The rules can be applied to rigid linear catheters, flexible linear catheters, and / or existing commercially available catheters (e.g., Orion). The rules can be more complex depending on the flexibility and shape of the catheter. At least some embodiments of the present application include rules applicable to catheters with deformable spline shapes.

[0135] At 912A, process 900A may include updating electrode positions based on a geometric model of the ablation catheter. In some embodiments, at 914A, process 900A may optionally include accessing a field map, and electrode positions may be estimated based on the measured electrical signals and the field map. The field map may be a pre-existing field map, for example, generated by a separate catheter or by mapping electrodes on an ablation catheter.

[0136] 9B-9E are system diagrams illustrating an exemplary process for facilitating ablation by irreversible electroporation, according to embodiments of the presently disclosed subject matter. At 906B, system 900B includes injecting a current through two or more electrodes. There are various ways in which the current can be injected. For example, at 906B and 906C, the current can be injected through two or more electrodes on the body surface and the corresponding potential can be measured through at least one electrode on the target catheter ("body surface dipole"). In embodiments, for example, at 906D, the current can be injected through two or more electrodes on the body surface and the corresponding potential can be measured through at least one electrode on the target catheter ("body surface and local dipole"). In embodiments, for example, at 906E, the current can be injected through two or more electrodes on the target catheter and the corresponding potential can be measured through at least one additional electrode on the target catheter ("local dipole").

[0137] At 908B-E, systems 900B-E include pre-processing. In embodiments, pre-processing may include measuring electrical signals at one or more ablation electrodes.

[0138] At 910B-E, systems 900B-E may include estimated electrode positions. The estimated electrode positions may include individual electrode positions, individual spline positions, and / or electrode assembly positions. Various data sources may be used to estimate the position of each individual electrode. For example, data sources may include electrical potential measurements obtained from a subject's catheter in response to current injected by electrodes on the body surface. This measurement may be made within the context of a field map (shown in FIG. 9C), optionally within the context of a field map (shown in FIGS. 9D-9E), or without a field map (shown in FIG. 9B). System 9B is an open impedance tracking system because it does not rely on a field map.

[0139] In system 900C, also known as a closed impedance tracking system, measurements must be made within the context of a field map. In systems 900D-E, where measurements are optionally made within the context of a field map, the system is either an open or closed impedance tracking system. The field map is optional, hence the "+ / -" symbols in 914D and 914E.

[0140] Field maps can be generated using a separate catheter or in a stepwise approach (eg, autologous field map generation) using electrodes on the shaft of the target catheter.

[0141] 9B-9E, a system for electroporation ablation includes steps 916B-E of applying a geometric model. The geometric model may include one or more constraints regarding one or more relative electrode positions of one or more ablation electrodes. In embodiments, the geometric model may include relative electrode positions of two ablation electrodes disposed on one spline of the one or more splines. In embodiments, the geometric model includes relative electrode positions of two or more ablation electrodes, each ablation electrode of the two or more ablation electrodes disposed on a respective spline of the one or more splines.

[0142] In an embodiment, the geometric model includes a first predetermined radius range for a first portion of one of the one or more splines. In an embodiment, the geometric model includes a second predetermined radius range for a second portion of the one or more splines, the second portion of the one or more splines being different from the first portion of the one or more splines, and the second predetermined radius range being different from the first predetermined radius range.

[0143] Applying the geometric models of 916B-E to the electrode positions estimated in 910B-E allows the systems 900B-E to determine a refined shape and position of the catheter relative to the 3D space of the mapping and navigation system. The process of applying geometric models to the estimated electrode positions can be repeated for a more accurate refined shape and position of the catheter.

[0144] In embodiments, systems 900B-E may include one or more outputs 918B-E. The one or more outputs may include visualization in a mapping system (e.g., on display 92 of FIG. 1 ), input to downstream functions, and / or EAM / anatomical structure generation / modification. In some embodiments, outputs 918B-E can be used and controlled for real-time ablation planning. In certain embodiments, outputs 918B-E can be used as inputs to a visualization system to provide real-time (e.g., with a delay of less than one second) information regarding the position, shape, orientation, and other characteristics of the catheter's electrode assembly.

[0145] Various modifications and additions can be made to the exemplary embodiments described without departing from the scope of the present disclosure. For example, while the above embodiments refer to particular features, the scope of the present invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations that fall within the scope of the claims, together with all equivalents thereof.

Claims

1. A system for electroporation ablation, A tracking electrode configured to deliver a tracking current, An ablation catheter comprising an electrode assembly and a deployment sensor, wherein the electrode assembly comprises a plurality of splines, each of which comprises a plurality of ablation electrodes positioned thereon, the ablation catheter is configured such that the electrode assembly can be positioned in close proximity to target tissue, the plurality of ablation electrodes are configured to measure electrical signals related to the tracking current, and the deployment sensor is configured to collect data related to the deployment state, Processor and The processor is equipped with, The measured electrical signals and collected data are received, Based on the measured electrical signals, the position of each ablation electrode relative to the tracking electrode is estimated. Based on the collected data, a geometric model is selected. Based on the geometric model of the ablation catheter and the estimated positions of the multiple ablation electrodes, the deployment state of the electrode assembly is determined. A system that is configured in such a way.

2. The system according to claim 1, wherein the deployment sensor is located in the electrode assembly.

3. The system according to claim 1, wherein the ablation catheter includes a handle, and the deployment sensor is located on the handle.

4. The system according to claim 1, wherein the ablation catheter further comprises a navigation sensor, and the processor is configured to generate a field map based on sensing signals collected by the plurality of ablation electrodes, each having a known position relative to the navigation sensor.

5. The system according to claim 1, wherein the geometric model includes one or more constraints relating to the relative positions of one or more of the plurality of ablation electrodes.

6. The system according to claim 5, wherein the geometric model includes the relative electrode positions of two ablation electrodes arranged on one of the plurality of splines.

7. The system according to claim 5, wherein the geometric model includes the relative electrode positions of two or more ablation electrodes, each positioned on one of the splines.

8. The system according to claim 1, wherein the tracking electrode includes a first tracking electrode configured to be placed on the surface of the patient's body and a second tracking electrode configured to be placed inside the patient's heart chamber.

9. The system according to claim 1, wherein the geometric model includes a first predetermined radius range of a first portion of one of the plurality of splines.

10. The system according to claim 9, wherein the geometric model includes a second predetermined radius range of a second portion of one of the plurality of splines, the second portion of one of the plurality of splines being different from the first portion of one of the plurality of splines, and the second predetermined radius range being different from the first predetermined radius range.

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