Method, system and apparatus for tracking ablation devices and generating lesion lines

Abstract

Systems, devices, and methods for electroporation ablation therapy are disclosed. An apparatus may be configured to activate a field generator to generate an electric field or a magnetic field such that a signal is received by a receiver coupled to an ablation device disposed adjacent to a tissue surface. Processed data associated with the signal may be obtained. A position and orientation of the ablation device may be determined based on the processed data. An intended ablation region of the ablation device in the tissue surface may be determined based on the position and orientation of the ablation device. A map of the tissue surface and a visual representation of the intended ablation region disposed in the map of the tissue surface may be displayed.

Description

[0001] Related Applications

[0002] This application is a continuation-in-part application of and claims priority to U.S. Application No. 16 / 785,392, filed on February 7, 2020, which claims priority to U.S. Provisional Application No. 62 / 940,219, filed on November 25, 2019. This application also claims priority to U.S. Provisional Application No. 62 / 940,219. The entire disclosure of each of the foregoing applications is incorporated herein by reference in its entirety. Technical Field

[0003] The embodiments described herein relate generally to medical devices for therapeutic electrical energy delivery, and more particularly to systems, apparatuses, and methods for tracking ablation devices (eg, ablation catheters) and creating lesion lines using these devices. Background Art

[0004] Pulsed field ablation using the application of high voltage pulses has been shown to be suitable for quickly and effectively generating lesions in cardiac tissue as well as other target anatomical structures. In the cardiac context, pulsed field ablation has been used for localized ablation or generating discrete localized lesions. For example, an ablation catheter configured for localized ablation can be used to deliver pulsed field ablation to cardiac tissue via irreversible electroporation.

[0005] In clinical catheterization laboratories, electroanatomical mapping systems using impedance tracking or impedance-based positioning systems can be used to provide three-dimensional visualization feedback of devices positioned in the patient's anatomy. Additionally or alternatively, electromagnetic tracking sensors can be integrated into the devices and used to track those devices within the patient's anatomy.

[0006] It may be desirable to track properties of an ablation device during an ablation procedure and use such information to assess ablation characteristics, for example, to assist in ablation procedure planning. Summary of the invention

[0007] Described herein are systems, devices, and methods for visualizing and generating localized tissue ablations using ablation catheters. In some embodiments, the ablation devices used in these systems can be deployed epicardially or endocardially in cardiac applications.

[0008] In some embodiments, an apparatus may include a memory; and a processor operably coupled to the memory, the processor being configured to: activate a field generator to generate an electric field or a magnetic field so that a signal is received by a receiver coupled to an ablation device arranged adjacent to a tissue surface; obtain processed data associated with the signal; determine a position and orientation of the ablation device based on the processed data; determine an expected ablation area of ​​the ablation device in the tissue surface based on the position and orientation of the ablation device; and display a map of the tissue surface and a visual representation of the expected ablation area in the map of the tissue surface via an output device.

[0009] In some embodiments, a method may include: receiving data representing a signal at a processor, the signal being received by a receiver coupled to an ablation device arranged adjacent to a tissue surface, the receiver receiving the signal in response to an electric field or a magnetic field generated by a field generator; determining, at the processor, a position and orientation of the ablation device based on the data representing the signal; determining, at the processor, an expected ablation area of ​​the ablation device in the tissue surface based on the position and orientation of the ablation device; and displaying a map of the tissue surface and a visual representation of the expected ablation area in the map of the tissue surface via an output device operably coupled to the processor.

[0010] In some embodiments, a system may include: a field generator configured to generate an electric field or a magnetic field; a signal generator configured to generate a pulse waveform for ablating tissue; an output device; and a processor operably coupled to the field generator, the signal generator, and the output device, the processor being configured to: activate the field generator to generate the electric field or the magnetic field so that the signal is received by a receiver coupled to an ablation device arranged adjacent to a tissue surface; obtain processed data associated with the signal; determine a position and orientation of the ablation device based on the processed data; determine an expected ablation area of ​​the ablation device in the tissue surface based on the position and orientation of the ablation device; cause the output device to display a map of the tissue surface and a visual representation of the expected ablation area in the map of the tissue surface; and in response to the expected ablation area corresponding to a desired ablation area, activate the signal generator to generate a pulse waveform to deliver to the ablation device so that the ablation device produces an ablated area corresponding to the expected ablation area.

[0011] In some embodiments, an apparatus may include: a memory; and a processor, which may be operably coupled to the memory, the processor may be configured to: activate a field generator to generate an electric field or a magnetic field so that a signal can be received by a receiver coupled to an ablation device arranged adjacent to a tissue surface; obtain processed data associated with the signal; determine the position and orientation of the ablation device based on the processed data; display a map of the tissue surface via an output device, the map of the tissue surface consisting of a plurality of points forming a point cloud; determine the closest distance from the ablation device to the tissue surface; in response to the closest distance being less than a predefined value, identify a set of points within a predefined distance from a distal end of the ablation device from a plurality of points; determine the centroid of the set of points; determine a local tangent plane of the surface extending through the centroid; determine a center of an expected ablation area based on the position and orientation of the ablation device relative to the local tangent plane, the center representing the location of the surface centroid of the ablation area; and display a visual representation of the expected ablation area in the map of the tissue surface via the output device.

[0012] In some embodiments, the expected ablation area may be a first expected ablation area, and the processor is further configured to: determine a second expected ablation area of ​​the ablation device in the tissue surface in response to a change in the position or orientation of the ablation device; and display via the output device a visual representation of the ablated area associated with the first expected ablation area in a mapping map of the tissue surface and a visual representation of the second expected ablation area in a mapping map of the tissue surface.

[0013] In some embodiments, the processor can be configured to display a visual representation of the ablated area and a visual representation of the second intended ablation area by: projecting the ablated area into a map of the tissue surface using a first set of markers; and projecting the second intended ablation area into a map of the tissue surface using a second set of markers different from the first set of markers.

[0014] In some embodiments, the ablation device may include a spline set, wherein each spline in the spline set includes a proximal electrode set and a distal electrode set, such that the spline set collectively includes a plurality of proximal electrodes and a plurality of distal electrodes, and the processor is configured to determine the position and orientation of the ablation device by: determining a geometric parameter set of the ablation device based on the processed data; determining a configuration of the ablation device based on the geometric parameter set; and determining at least one of the position and orientation of the ablation device based on the determined configuration of the ablation device and the processed data.

[0015] In some embodiments, the processor can be configured to determine the orientation of the ablation device at least by determining a longitudinal unit vector associated with the ablation device. In some embodiments, the processor can be configured to determine the orientation of the ablation device at least by identifying a deployment configuration that: (1) has an associated geometric parameter set that most closely matches the determined geometric parameter set; and (2) is from a set of deployment configurations that each have an associated geometric parameter set.

[0016] In some embodiments, the processor can be configured to identify the deployment configuration having an associated set of geometric parameters that most closely matches the determined set of geometric parameters by using a least squares method. In some embodiments, an amplifier can be configured to amplify a signal received by the receiver, and the processor is configured to obtain the processed data by digitizing and processing the signal amplified by the amplifier. In some embodiments, the processor can also be configured to display a visual representation of the ablation device via the output device based on the position and orientation of the ablation device.

[0017] In some embodiments, the ablation device may include a plurality of electrodes, and the processor is further configured to: identify an electrode in contact with the tissue surface from the plurality of electrodes, the center of the expected ablation area being at a location corresponding to the location of the electrode; and identify an expected ablation area shape from a plurality of expected ablation area shapes based on the position and orientation of the ablation device, the expected ablation area having the expected ablation area shape. In some embodiments, the processor may also be configured to construct a map of the tissue surface based on processed data associated with the signal received by the receiver when the ablation device is navigated to a plurality of locations along the tissue surface. In some embodiments, the predefined value may be less than about 4 mm and the predefined distance may be less than about 3 cm.

[0018] In some embodiments, a method may include: receiving data representing a signal at a processor in a processor set, the signal being received by a receiver coupled to an ablation device arranged adjacent to a tissue surface, the receiver receiving the signal in response to an electric field or a magnetic field generated by a field generator; determining, at a processor in the processor set, a position and orientation of the ablation device based on the data representing the signal; displaying a map of the tissue surface via an output device operably coupled to a processor in the processor set, the map of the tissue surface being composed of a plurality of points forming a point cloud; determining, at a processor in the processor set, a closest distance from the ablation device to the tissue surface; in response to the closest distance being less than a predefined value, identifying, at a processor in the processor set, from a plurality of points a set of local points within a predefined distance from a distal end of the ablation device; determining, at a processor in the processor set, a local tangent plane of the surface based on the set of local points; determining, at a processor in the processor set, a center of an expected ablation area based on the position and orientation of the ablation device relative to the local tangent plane; and displaying, via the output device, a visual representation of the expected ablation area in the map of the tissue surface.

[0019] In some embodiments, the method may further include activating a signal generator to generate a pulse waveform for delivery to the ablation device, so that the ablation device produces an ablated region corresponding to the intended ablation region. In some embodiments, the method may further include displaying, via the output device and upon delivery of the pulse waveform, a visual representation of the ablated region in a map of the tissue surface that is distinct from a visual representation of the intended ablation region.

[0020] In some embodiments, receiving data representing a signal received by the receiver may be when the ablation device is in a first position, the position of the ablation device is the first position of the ablation device, the orientation of the ablation device is the first orientation of the ablation device, and the expected ablation area is a first expected ablation area, and the method further includes: when the ablation device is located at a second position different from the first position, receiving data representing a signal received by the receiver in response to the electric field or the magnetic field; when the ablation device is in the second position, determining a second position and a second orientation of the ablation device based on the data representing the signal; determining a second expected ablation area of ​​the ablation device in the tissue surface based on the second position and the second orientation of the ablation device; and displaying, via the output device, a visual representation of the ablated area using a first set of markers and a visual representation of the second expected ablation area using a second set of markers different from the first set of markers.

[0021] In some embodiments, the ablated region may be a first ablated region, the method further comprising: in response to the second intended ablation region having a partial overlap with the first ablated region that is greater than a threshold, activating the signal generator to generate a pulse waveform to deliver to the ablation device, so that the ablation device produces a second ablated region corresponding to the second intended ablation region, the first ablated region and the second ablated region forming part of a continuous lesion in the tissue surface. In some embodiments, the threshold may be a predetermined value.

[0022] In some embodiments, the signal may be a first signal, and the method further comprises: receiving data representing a second signal received by the receiver in response to an electric field or a magnetic field generated by the field generator at each of a plurality of locations to which the ablation device is navigated, the ablation device comprising a plurality of electrodes; identifying, at each of the plurality of locations from the plurality of electrodes, at least one electrode in contact with the tissue surface based on at least one of: (i) data representing a second signal received by the receiver at the location; or (ii) electrocardiogram (ECG) data recorded from the electrode; generating a point cloud comprising the plurality of points, wherein each point from the plurality of points corresponds to a location from at least one electrode identified at a location different from the plurality of locations; and constructing a map of the tissue surface using the point cloud.

[0023] In some embodiments, the ablation device may include a rack set, wherein each rack in the rack set includes a proximal electrode set and a distal electrode set, such that the rack set collectively includes a plurality of proximal electrodes and a plurality of distal electrodes, and determining the position and orientation of the ablation device includes: determining a geometric parameter set of the ablation device based on received data representing the signal; determining a configuration of the ablation device based on the geometric parameter set; and determining at least one of the position or orientation of the ablation device based on the determined configuration of the ablation device and the received data representing the signal. In some embodiments, the method may also include displaying a visual representation of a mapping of the ablation device relative to the tissue surface via the output device based on the position and orientation of the ablation device.

[0024] In some embodiments, a system may include: a field generator configured to generate an electric field or a magnetic field; a signal generator configured to generate a pulse waveform for ablating tissue; an output device; and a processor operably coupled to the field generator, the signal generator, and the output device, the processor being configured to: activate the field generator to generate the electric field or the magnetic field so that the signal is received by a receiver coupled to an ablation device disposed adjacent to a tissue surface; obtain processed data associated with the signal; determine a position and orientation of the ablation device based on the processed data; cause the output device to display a map of the tissue surface, the map of the tissue surface being composed of a plurality of points forming a point cloud; Determine a closest distance from the ablation device to the tissue surface; in response to the closest distance being less than a predefined value, identify a local point set from a plurality of points that is within a predefined distance from a distal end of the ablation device; determine a local tangent plane of the surface based on the local point set; and determine a center of an intended ablation area based on the position and orientation of the ablation device relative to the local tangent plane; cause the output device to display a visual representation of the intended ablation area in a map of the tissue surface; and in response to the intended ablation area corresponding to a desired ablation area, activate a signal generator to generate a pulse waveform to deliver to the ablation device so that the ablation device produces an ablated area corresponding to the intended ablation area.

[0025] In some embodiments, the field generator may include a set of electrode patches that generate one or more electric fields, the electric field or magnetic field including one or more electric fields generated by the set of electrode patches. In some embodiments, the field generator may include a set of transmitter coils, each of which generates a time-varying magnetic field, the electric field or magnetic field including the time-varying magnetic field generated by the set of transmitter coils. In some embodiments, the processor may also be configured to: in response to activating the signal generator, cause the output device to change the visual representation of the intended ablation area to indicate that the intended ablation area is ablated.

[0026] In some embodiments, the ablation device may include a rack set, wherein each rack in the rack set includes a proximal electrode set and a distal electrode set, so that the rack set collectively includes multiple proximal electrodes and multiple distal electrodes, and the processor is configured to determine the position and orientation of the ablation device in the following manner: determining a geometric parameter set of the ablation device based on the processed data; determining a configuration of the ablation device based on the geometric parameter set; and determining at least one of the position or orientation of the ablation device based on the determined configuration of the ablation device and the processed data.

[0027] In some embodiments, the ablation device comprises a plurality of racks configured to form a basket shape. In some embodiments, the ablation device comprises a distal portion comprising a linear shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1A is a schematic diagram of a mapping / device location system according to an embodiment. Figure 1B is a schematic diagram of an electroporation system according to an embodiment.

[0029] Figure 2A is a side view of an ablation catheter according to an embodiment. Figure 2B yes Figure 2A Front view of the ablation catheter depicted in FIG.

[0030] Figure 3 is a schematic cross-sectional view of an electrode assembly of an ablation catheter according to an embodiment.

[0031] Figure 4 is a simulated illustration of an ablation device within a patient's anatomy, according to an embodiment.

[0032] Figure 5 is a simulated illustration of an ablation device within a patient's anatomy, according to an embodiment.

[0033] Figure 6 is a simulated illustration of an ablation device within a patient's anatomy, according to an embodiment.

[0034] Figure 7 is a simulated illustration of an ablation device within a patient's anatomy, according to an embodiment.

[0035] Figure 8 is a simulated illustration of an ablation device within a patient's anatomy, according to an embodiment.

[0036] Fig. 9A and Fig. 9B is a flow chart of a tissue mapping and ablation procedure according to an embodiment.

[0037] Fig.10 is a perspective view of an anatomical surface map according to an embodiment.

[0038] Fig.11 is a perspective view of an anatomical surface map according to an embodiment.

[0039] Fig.12 is a perspective view of an anatomical surface map according to an embodiment.

[0040] Fig.13 is a perspective view of an anatomical surface map according to an embodiment.

[0041] Fig.14is a simulated illustration of an ablation device within a patient's anatomy, according to an embodiment.

[0042] Fig.15 is a simulated illustration of an ablation device within a patient's anatomy, according to an embodiment.

[0043] Fig.16 is a simulated illustration of an ablation device within a patient's anatomy, according to an embodiment.

[0044] Fig.17 is a perspective view of an anatomical surface map according to an embodiment.

[0045] Fig.18 is a perspective view of an anatomical surface map according to an embodiment.

[0046] Fig.19 is a perspective view of an anatomical surface map according to an embodiment.

[0047] Fig. 20 is a perspective view of an anatomical surface map according to an embodiment. DETAILED DESCRIPTION

[0048] Described herein are systems, devices, and methods for selectively and rapidly applying pulsed electric fields to ablate tissue via irreversible electroporation.In general, the systems, devices, and methods described herein can be used to generate lesion lines using an ablation device (eg, a focal ablation device).

[0049] In some embodiments, the systems, devices, and methods described herein provide spatial tracking of an ablation device (e.g., a catheter) in a body cavity to assist in tissue ablation, such as generating a continuous and transmural lesion line using a local ablation catheter. For example, such spatial tracking can provide real-time tracking of the spatial location and orientation of the ablation device. Systems, devices, and methods incorporating spatial tracking capabilities can enable real-time program planning and can be applied in the context of pulsed electric field ablation procedures, where high voltage pulse waveforms are delivered to generate lesions using irreversible electroporation.

[0050] Pulsed electric field ablation for cardiac tissue ablation has recently been demonstrated to be a suitable modality for rapidly and efficiently generating ablation lesions. In the cardiac setting, localized ablation or the generation of discrete localized lesions is a relevant application of pulsed electric field ablation. In clinical catheterization laboratories, electroanatomical mapping systems (e.g., manufactured by Biosense Webster Inc.) are used to generate ablation lesions. system, or NavX manufactured by Abbott Laboratories TM The system can be used to provide three-dimensional visualization feedback for catheter devices positioned within cardiac anatomical structures or chambers.

[0051] Electromagnetic tracking sensors can be integrated into catheter devices using electrodes configured to track device position within a three-dimensional volume of interest (e.g., in real time). Suitable electromagnetic tracking or positioning systems for some medical applications include, for example, systems and sensors manufactured by Northern Digital Inc. By using a catheter endowed with such a sensor on the endocardium to navigate to different locations within a heart chamber, the positioning data of the catheter electrodes and / or the ECG signals recorded from the electrodes can be used to reconstruct the surface anatomy of the heart chamber.

[0052] Additionally or alternatively, the device location tracking system may use an electric field or voltage gradient generated by a collection of surface electrode patches on a patient (e.g., using a potential difference set between the surface electrode patches) to determine the location of a device (e.g., a catheter). Where at least three such independently paired potential differences are not all in the same plane, the three-dimensional location of the electrodes may be estimated based on voltage potentials measured by the electrodes or sensors relative to one or more surface patches, or equivalently, impedance measurements may be estimated based on measured currents and / or voltages. Suitable techniques and methods for estimating spatial location using such potential differences or voltage gradients of a collection of electrodes (also referred to as impedance tracking or impedance-based localization systems) are incorporated into electroanatomical mapping systems, such as the NavX 3D imaging system manufactured by Abbott Laboratories. TM system, Rhythmia manufactured by Boston Scientific Inc. TM system, or manufactured by Biosense Webster Inc. In some embodiments, when a catheter device includes an electromagnetic sensor for electromagnetic tracking and is further used with an impedance tracking system, the positioning of electrodes on the catheter can be estimated more accurately than using impedance tracking without electromagnetic tracking.

[0053] Given a local catheter configured to deliver pulsed field ablation of a lesion (e.g., a lesion produced by irreversible electroporation) with a high voltage pulse waveform, the characteristics (e.g., spatial extent and geometry) of a lesion delivered using such a catheter with a given pulsed field ablation waveform and at a given voltage can be determined using lesion data and / or computational modeling from studies or past procedures (e.g., preclinical or animal studies and / or procedures). Depending on the electrode geometry of the local catheter, the lesion geometry generated by such ablation will typically depend, at least in part, on the orientation of the device relative to the local tissue surface or wall.

[0054] The systems and methods described herein relate to displaying an expected lesion geometry or ablation area on an anatomical map or surface rendering, which can enable a series of lesions (e.g., continuous and / or transmural) to be effectively generated in a predetermined anatomical region. In some embodiments, a local ablation catheter configured to generate a pulsed electric field ablation lesion can take a variety of geometric forms. In some embodiments, the methods, systems, and devices disclosed herein may include one or more of the methods, systems, and devices described in U.S. application serial number 16 / 375,561, filed on April 4, 2019, and entitled “SYSTEMS, DEVICES, AND METHODS FOR FOCAL ABLATION,” U.S. application serial number 16 / 886,514, filed on May 28, 2020, and entitled “SYSTEMS, DEVICES, AND METHODS FOR FOCALABLATION,” and international application number PCT / US2020 / 037948, filed on June 16, 2020, and entitled “SYSTEMS, DEVICES, AND METHODS FOR FOCAL ABLATION,” the contents of each of which are incorporated herein by reference in their entirety.

[0055] As used herein, the term "electroporation" refers to applying an electric field to a cell membrane to change the permeability of the cell membrane to the extracellular environment. As used herein, the term "reversible electroporation" refers to applying an electric field to a cell membrane to temporarily change the permeability of the cell membrane to the extracellular environment. For example, a cell undergoing reversible electroporation may be observed to temporarily and / or intermittently form one or more holes in its cell membrane, and after removing the electric field, the one or more holes are closed. As used herein, the term "irreversible electroporation" refers to applying an electric field to a cell membrane to permanently change the permeability of the cell membrane to the extracellular environment. For example, a cell undergoing irreversible electroporation may be observed to form one or more holes in its cell membrane, and after removing the electric field, the one or more holes remain.

[0056] system

[0057] Disclosed herein are systems and devices configured to generate localized ablation lesions in tissue. Typically, the systems described herein for ablating tissue using high voltage pulse waveforms may include a device tracking or positioning component, an ECG recording or monitoring component, a cardiac stimulator, and an ablation component. The systems, methods, and embodiments described in this disclosure are suitable for synchronous or asynchronous ablation delivery. In addition, as described herein, the systems and devices may be deployed in the endocardium and / or epicardium to treat cardiac fibrillation.

[0058] Figure 1Ais a schematic diagram of a mapping or localization system (10) (e.g., electromagnetic tracking) including a field generator (46) including a set of transmitters configured to generate an electromagnetic field. In an embodiment including an impedance-based tracking system, the electric field generator (46) may include a set of electrode patches, the potential difference between subsets of which remains constant over a frequency range. In an embodiment including an electromagnetic tracking system (10), the electric field generator (46) may include a set of transmitter coils, each transmitter coil configured to generate a time-varying magnetic field. The generated electric or magnetic field (for an impedance-based tracking system or for an electromagnetic tracking system, or both types of systems, respectively) is typically received as a signal (voltage, current, or both) by a set of receivers (18) of a medical device (e.g., an ablation catheter, a focal ablation device (110)) for spatial tracking. The received signal can be amplified by an amplifier (43) and then digitized and processed by one or more processors (42). The one or more processors (42) can also be configured to control or drive the electric field generator (46). The one or more processors (42) may be configured to estimate and / or determine a position and / or orientation of the medical device based on the received signals. The estimated position and orientation information may be displayed on an input / output device (48) (e.g., a graphics display (160)) in the form of a visual rendering of the spatial tracking device. In some embodiments, the input / output device (48) may allow a user to interact with the rendering (e.g., view it from different perspectives) and / or visualize the device together with constructed or imaged object anatomy.

[0059] Figure 1Bis a schematic diagram of an electroporation system (100) including an ablation device (110), a mapping system (140), a pulse waveform generator (130), and an optional cardiac stimulator (180). The ablation device (110) may include one or more electrodes (116) configured to generate a pulsed electric field for pulsed field ablation, for example via irreversible electroporation. The ablation device (110) may include one or more receivers (118) configured to receive a signal (voltage, current, or both), for example, from a field generator (146) of the mapping system (140), as further described below. In some embodiments, the ablation device (110) may be an ablation catheter that can be introduced into a cardiac anatomical structure, such as the endocardial space of an atrium. The distal portion of the ablation catheter may include one or more electrodes (116) configured to deliver ablation energy (e.g., pulsed electric field energy) to nearby tissue. The one or more electrodes (116) may be co-wired or independently addressable. In operation (e.g., during an ablation procedure), a voltage (e.g., an ultrashort, high voltage pulse) may be applied to a selected subset of the electrodes of the ablation device. Each electrode (116) may include an insulated electrical lead configured to maintain a potential difference between about 200V and about 3,000V across its thickness without dielectric breakdown. In some embodiments, one or more electrodes (116) may include a plurality of electrodes that may be grouped into one or more anode-cathode subsets, such as, for example, a subset including one anode and one cathode, a subset including two anodes and two cathodes, a subset including two anodes and one cathode, a subset including one anode and two cathodes, a subset including three anodes and one cathode, a subset including three anodes and two cathodes, and / or the like, but not limited thereto. Further details and example embodiments of the ablation device (110) are provided in subsequent figures.

[0060] The ablation device (110) is operably coupled to a mapping system (140). The mapping system (140) may include components that are functionally and / or structurally similar to the ablation mapping system (10), as described above with respect to Figure 1AAs described. For example, the mapping system (140) may include a processor (142), a memory (144), a field generator (146), and an input / output device (148). The processor (142) may be any suitable processing device configured to run and / or execute a set of instructions or codes. The processor (142) may be, for example, a general purpose processor, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a digital signal processor (DSP), and / or the like. The processor may be configured to run and / or execute application processes and / or other modules, processes, and / or functions associated with the system and / or a network associated therewith (not shown). A variety of component types of basic device technologies may be provided, such as metal-oxide semiconductor field-effect transistor (MOSFET) technology, such as complementary metal oxide semiconductor (CMOS); bipolar technology, such as emitter coupled logic (ECL); polymer technology (e.g., silicon-conjugated polymer and metal-conjugated polymer-metal structure); mixed analog and digital and / or the like. The processor (142) may be configured to control the field generator (146) to generate one or more electric, magnetic, or electromagnetic fields. In some embodiments, the field generator (146) may include a set of electrode patches externally disposed on the patient, which may be used to generate the electric field. In some embodiments, the field generator (146) may include a set of transmitter coils configured to generate a time-varying magnetic field. The field generated by the field generator (146) may be received by one or more receivers (118). In some embodiments, the one or more receivers (118) may be integrated into the ablation device (110). For example, electrodes on the device may sense a voltage potential generated by the one or more field generators (146). Alternatively or additionally, the one or more receivers (118) may be disposed near, within, or adjacent to the ablation device (110), such as on a probe or sensor disposed within a lumen of the ablation device (110). The processor (142) may be configured to determine the position, orientation, and / or configuration of the ablation device (110) or other tracked device. For example, and as further described in further embodiments below, the processor (142) can process data received by one or more receivers (118) and / or analyze the data to determine the position or orientation of the ablation device (110) relative to a surface or wall of the heart, or the configuration (e.g., shape, expanded state) of the ablation device (110) when it is deployed within the cardiac space.The processor (142) may be configured to determine an intended ablation region in the target anatomy given information associated with the patient, the ablation device (e.g., position, orientation, and / or configuration), pulse waveform parameters, etc., as further described in the example embodiments below. During the generation of continuous and transmural lesions, the processor (142) may be configured to determine an intended ablation region and / or an ablated region.

[0061] The memory (144) can be, for example, a random access memory (RAM), a memory buffer, a hard drive, an erasable programmable read-only memory (EPROM), an electrically erasable read-only memory (EEPROM), a read-only memory (ROM), a flash memory, etc. The memory can store instructions to cause the processor (142) to execute modules, processes and / or functions, such as field generation and / or position and orientation determination.

[0062] The input / output device (148) may be used to present information and / or receive information from a user and / or other computing devices (e.g., a remote computing device operably coupled to the electroporation system (100) via a wired and / or wireless connection). In some embodiments, the processor (142) (or another processor) may be configured to generate information and control the input / output device (148) to present the information, for example, by using a display, an audio device, a projector, etc. The input / output device (148) may include, for example, a user interface, such as a display, an audio device, etc., which enables output to be presented to a user and / or input to be received from a user. In some embodiments, the input / output device (148) may display a visual representation of a particular anatomical structure (e.g., a cardiac anatomical structure) and a visual representation of a tracked device (e.g., an ablation device (110)) within the anatomical structure. In operation (e.g., during an ablation procedure), the visual representation may display the position, orientation, and / or configuration of the tracked device as it moves through the target anatomical structure, for example, in real time (e.g., within a fraction of a second). In some embodiments, the input / output device (148) can be used to receive input from a user that specifies pulse waveform parameters (e.g., voltage, duration, delay, etc.), properties or characteristics of the ablation device (e.g., type of ablation device, deployment state, etc.), and / or other information that assists in determining the intended ablation zone. In some embodiments, the input / output device (148) can be configured to display the intended ablation zone and / or the ablated zone in real time, for example, during an ablation procedure. In some embodiments, the input / output device (148) can be configured to display different features or components (e.g., surrounding anatomical structures, ablation device, intended ablation zone, and / or ablated zone) using different markings, patterns, visual renderings, and / or colors to show during the overlay of components on other components.

[0063] The pulse waveform generator (130) can be configured to generate an ablation pulse waveform for irreversible electroporation of tissue (such as, for example, a pulmonary vein ostium). For example, the pulse waveform generator (130) can generate a pulse waveform and deliver it to an ablation device (110) that generates a pulsed electric field that can ablate tissue. In some embodiments, the pulse waveform generator (130) is configured to generate an ablation pulse waveform that is synchronized with the cardiac cycle of the heart (e.g., within a common refractory period window of an atrial pacing signal and a ventricular pacing signal). For example, in some embodiments, the common refractory period window can begin substantially immediately after the pacing signal (or after a very small delay) and last thereafter for a duration of approximately 250 milliseconds (ms) or less. In some embodiments, the entire pulse waveform can be delivered within this duration, while in other embodiments, portions of the pulse waveform can be delivered within this duration, while other portions are delivered during the common refractory period window of a subsequent cardiac cycle. In such embodiments, synchronization with the cardiac cycle may be achieved through the use of pacing or through appropriate gating of ablation delivery based on R-wave detection in ECG recordings.

[0064] In some embodiments, the cardiac stimulator (180) can be configured to generate one or more pacing signals and provide these signals to an optional pacing device (120) disposed near the target anatomical structure. The pacing device (120) can include a collection of one or more electrodes 122 that can receive pacing signals and deliver them to the cardiac anatomical structure, for example, to pace the heart. One or both of atrial and / or ventricular pacing signals can be generated and delivered to the heart. In some embodiments, the pacing device (120) can be configured to sense and / or analyze information about the patient (e.g., cardiac signals) and provide this information to one or more of the mapping system (140) and / or the pulse waveform generator (130) to further assist in controlling the operation of these devices (e.g., initiating or interrupting pulse waveform delivery, determining an intended ablation area and / or an ablated area, etc.).

[0065] In some embodiments, the cardiac stimulator (180) and the pulse waveform generator (130) can communicate with each other (e.g., to coordinate the timing of pulse waveform delivery, the timing of pacing signal delivery). In some embodiments, the cardiac stimulator (180) can be integrated with the pulse waveform generator (130) in a single console. In some embodiments, the cardiac stimulator (180) and the pulse waveform generator (130) can communicate with other devices (e.g., the mapping system (140) or a remote computing device) directly or via, for example, one or more networks (each of which can be any type of network). A wireless network can refer to any type of digital network that is not connected by any kind of cable. However, a wireless network can be connected to a wired network to interface with the Internet, other carrier voice and data networks, business networks, and personal networks. Wired networks are typically carried by copper twisted pair, coaxial cable, and / or fiber optic cable. There are many different types of wired networks, including wide area networks (WANs), metropolitan area networks (MANs), local area networks (LANs), campus networks (CANs), global area networks (GANs) (such as the Internet), and virtual private networks (VPNs). Hereinafter, a network refers to any combination of wireless, wired, public and private data networks that are typically interconnected through the Internet to provide a unified networking and information access solution.

[0066] In some embodiments, the pulse waveform generator (130) and / or the cardiac stimulator (180) are operably coupled to the mapping system (140) so that information about pulse waveforms, pacing signals, and / or sensed signals (e.g., sensed cardiac signals from the pacing device (120)) can be provided to the mapping system (140), for example to assist in device positioning and / or intended ablation determination. In some embodiments, the mapping system (140) and / or one or more processors associated with the pulse waveform generator (130) and / or the cardiac stimulator (180) can be integrated into one or more controllers that can be used to control one or more components of each of these devices.

[0067] Although not depicted, cardiac stimulator (180) and pulse waveform generator (130) may include one or more processors, which may be any suitable processing device configured to run and / or execute a set of instructions or code, similar to processor (142).

[0068] Although not depicted, cardiac stimulator (180) and pulse waveform generator (130) may include one or more memories or one or more storage devices, similar to memory (144). The memories may store instructions to cause a processor of either cardiac stimulator (180) or pulse waveform generator (130) to execute modules, processes, and / or functions, such as pulse waveform generation and / or cardiac pacing.

[0069] Figure 2A and Figure 2B is a schematic diagram of an embodiment of an ablation device (eg, a focal ablation device). Figure 2A A catheter device (200) configured to receive a pulse waveform and generate an electric field for ablating cardiac tissue is shown. The ablation device (200) may include an outer catheter shaft (210), an inner catheter shaft (220), a collection of racks (230), and electrodes (232, 234, 236, 238). The outer catheter shaft (210) may include a distal end, wherein the collection of racks (230) ( Figure 2A and Figure 2B The proximal end of the inner catheter shaft (220) is symmetrically coupled to the inner catheter shaft (220) within the lumen of the outer catheter shaft (210). In some embodiments, the inner catheter shaft (220) can be configured to extend beyond the outer catheter shaft (210). Figure 2B , the distal end of the collection of racks (230) can be coupled to the distal end of the inner catheter shaft (220) via a distal cap (240). In some embodiments, the inner catheter shaft (220) can be configured to be actuated (e.g., deployed, retracted) using a control mechanism (e.g., an actuator), such as, for example, a knob or rocker (not shown) in a catheter handle, which can transform the collection of racks (230) (e.g., a rack basket) into a curved or changed configuration, for example, from a substantially linear shape to a bulb-like shape, such as Figure 2A . The collection of racks (230) can be configured in a variety of configurations having different shapes and diameters, from undeployed (e.g., compressed within an outer catheter lumen or in a stationary or unconstrained configuration) to partially deployed to fully deployed. In other words, the collection of racks (230) can be deployed over a range of continuously larger deployments that extend the maximum diameter of the deployed shape of the racks (230) over a range of deployed forms or deployed configurations. For example, the collection of racks (220) can be transformed into a semi-deployed configuration having a diameter between the diameter of the undeployed configuration and the diameter of the fully deployed configuration.

[0070] In some embodiments, one or more of the racks (230) may include one or more of a set of proximal electrodes (232, 234) and distal electrodes (236, 238). In some embodiments, a rack in the set of racks (230) may include between about 1 and about 8, inclusive, proximal electrodes (232, 234) and between about 1 and about 8, inclusive, distal electrodes (236, 238). In some embodiments, the device (200) may include between about 2 and about 12 racks, including all ranges and subvalues ​​therebetween.

[0071] In some embodiments, an ablation device (e.g., ablation device (110, 200)) can be combined with a receiver (e.g., receiver (118)) implemented as an electromagnetic tracking sensor for tracking the position or orientation of the ablation device. Together with device configuration calculations as described herein, the electromagnetic positioning data can provide refined (e.g., improved) spatial positioning of all device electrodes. In such embodiments, the ablation device can be used to navigate to different locations within a cardiac chamber on the endocardium while collecting positioning data and / or cardiac data (e.g., recorded using one or more electrodes of the ablation device), which positioning data and / or cardiac data can then be used to construct a virtual representation of the surface anatomy of the cardiac chamber.

[0072] Additionally or alternatively, in some embodiments, an ablation catheter (e.g., ablation device (110)) may include a receiver implemented as an electrode configured to measure a voltage and / or current induced by an electric field generated by a collection of surface patches. In such embodiments, the collection of surface patches may be configured to generate an electric field in multiple planes, wherein the voltage and / or current signals are measured by the electrodes of the ablation catheter (or such measurements are used to estimate impedance).

[0073] Although in Figure 2A and Figure 2B , an ablation device (110) having a basket shape is depicted, but it is understood that one or more ablation devices suitable for the applications described herein may have a basket shape. Figure 2A and Figure 2B . For example, other exemplary ablation devices may include a linear focal ablation catheter having an electrode collection arranged along a distal portion of the catheter shaft. Suitable examples of linear ablation catheters are described in U.S. Provisional Patent Application No. 62 / 863,588, entitled “Systems, Devices, and Methods for Focal Ablation,” filed on June 19, 2019, the disclosure of which is incorporated herein by reference. The electrode collection may include a distal electrode collection and a proximal electrode collection arranged on a single linear axis. In some embodiments, the distal electrode collection may include a distal cap electrode. The distal device geometry can generally be characterized by a set of parameters including, for example, the length and diameter of the electrode, and the separation distance between adjacent electrodes. Similar to the above description of Figure 2A and Figure 2B For a given geometric arrangement of electrodes on a local ablation catheter device, the distal device geometry or generally the electrode geometry can be characterized by a set of geometric parameters, as shown in the description of the ablation catheter shown in FIG.

[0074] method

[0075] Also described herein are methods for determining an intended ablation area during a tissue ablation procedure performed in or near one or more cardiac chambers using the systems and devices described herein. In an embodiment, one or more cardiac chambers may be the left atrium and include its associated pulmonary veins, and the devices and methods described herein may also be used for other cardiac chambers. Typically, one or more catheters may be advanced to a target location through the vascular system in a minimally invasive manner. For example, an ablation device may be advanced through the vascular system via a guidewire and through a deflectable sheath. The sheath may be configured to deflect and help guide a local ablation catheter through the vascular system and one or more predetermined targets (e.g., pulmonary vein ostia). An expander may be advanced over a guidewire and configured to create and expand a transseptal opening during and / or prior to use. The methods described herein include introducing and arranging an ablation device (e.g., ablation device (110, 200)) in contact with one or more pulmonary vein ostia or sinus regions. A pacing signal may be delivered to the heart and / or measure cardiac activity using a cardiac stimulator (e.g., cardiac stimulator (180)). Spatial characteristics (e.g., position, orientation, configuration) of the ablation device and tissue can be determined and used to generate an expected ablation area and / or tissue map for display. Pulse waveforms can be delivered by one or more electrodes of the ablation device to ablate tissue. In some embodiments, the ablation energy can be delivered synchronously with cardiac pacing. In some embodiments, the voltage pulse waveforms described herein can be applied during the refractory period of the cardiac cycle to avoid disrupting the sinus rhythm of the heart. As the device navigates through the tissue and additional pulse waveforms are delivered to the tissue, a tissue map including ablated tissue and the expected ablation area can be updated in real time on the display.

[0076] A pulse waveform can be generated and delivered to one or more electrodes of the device to ablate tissue. In some embodiments, the pulse waveform can be generated synchronously with the pacing signal of the heart to avoid disrupting the sinus rhythm of the heart. In some embodiments, the electrodes can be configured in an anode-cathode subset. Additionally or alternatively, the pulse waveform can include multiple levels of architecture to reduce total energy delivery, for example, as described in International Application Serial No. PCT / US2019 / 031135, filed on May 7, 2019 and entitled "SYSTEMS, APPARATUSES AND METHODS FOR DELIVERY OF ABLATIVE ENERGY TO TISSUE", the disclosure of which is incorporated herein by reference. In some embodiments, the ablation device described herein (e.g., ablation device (110, 200)) can be used for epicardial and / or endocardial ablation. Examples of suitable ablation catheters are described in International Application Serial No. PCT / US2019 / 014226, which is incorporated by reference above.

[0077] Fig. 9A An example method (900) of tissue mapping and ablation according to embodiments described herein is provided. The method (900) may be performed by any of the mapping and / or ablation systems described herein, including, for example, the systems (10, 100). In particular, the method (900) may be performed by a mapping system or a processor (e.g., processor (42, 142)) or a controller associated with the system. At (902), the method (900) includes introducing an ablation device (e.g., ablation device (110, 200)) into a cardiac chamber (e.g., an endocardial space) to contact or be proximate to cardiac tissue. At (904), the ablation device may be navigated to a predetermined location, such as near a tissue surface. For example, the ablation device may be positioned near or in contact with a radially inner surface of a lumen (e.g., one or more pulmonary vein ostia) for mapping and / or tissue ablation. Optionally, at (906), the ablation device may be transformed into one of a plurality of configurations (e.g., an expanded state). For example, the ablation device can be transformed from a fully undeployed configuration to a fully deployed configuration or any configuration in between (e.g., one or more partially deployed configurations). In some embodiments, the ablation device may include a rack set, wherein each rack from the rack set includes a proximal electrode set and a distal electrode set, such that the rack set collectively includes a plurality of proximal electrodes and a plurality of distal electrodes. In some embodiments, a user can control an actuator (e.g., a handle) to transform the rack set between different deployed configurations.

[0078] In some embodiments, at (908), spatial information associated with the ablation device and tissue can be determined. For example, in response to the electric field and / or magnetic field generated by the field generator, a signal can be received at a receiver (e.g., a sensor, an electrode, etc.) coupled to or integrated into the ablation device. Data representing the signal received by the receiver can be received at a processor (e.g., processor (42, 142)), which can further process and / or analyze such information. Based on such analysis, spatial information (e.g., position, orientation, configuration) of the ablation device can be determined at the processor.

[0079] For example, such analysis may involve determining one or more geometric parameters that characterize the distal end of the ablation device. In some embodiments, given a known distal geometry of the distal portion of the ablation device (e.g., a local ablation catheter), the shape of the ablation device may be characterized by a set of geometric parameters for a given rack configuration. For example, Figure 3As shown in , the centroid of the proximal electrode on each rack (not shown for clarity) lies on a proximal circle (300), while the centroid of the distal electrode on each rack (not shown for clarity) lies on a distal circle (320). The proximal and distal circles (300, 320) lie in parallel planes and are separated by a distance b (340). The proximal circle (300) has a diameter d1 (310) and the distal circle (320) has a diameter d2 (330). The geometry of the distal portion of the ablation device can be characterized by these parameters.

[0080] In some embodiments, the impedance-based positioning system can be configured to generate the spatial coordinates of the proximal electrode and the distal electrode of the ablation device. Due to the inhomogeneity of the tissue, conventional impedance-based positioning systems are prone to errors. As described herein, the positioning system can generate an improved (or refined) spatial coordinate estimate of the distal portion of the focal ablation device. Given the coordinates of the proximal electrode of the ablation device obtained from the impedance-based positioning system, the center of mass of the proximal electrode on each rack can be determined. From this center of mass set on each rack, the center of mass x1 of these centers of mass of the proximal electrode can be determined. The center of mass x1 can be used to calculate the center of the best fit circle C1 (corresponding to the proximal electrode) with a diameter d1, which can be calculated using, for example, least squares fitting. Similarly, the center of mass of the distal electrode of the rack set can be determined, and the center of mass x2 of the center of mass of the distal electrode can be determined. The center of mass x2 can be used to calculate the center of the best fit circle C2 (corresponding to the distal electrode) with a diameter d2. The diameter d1 of the center of mass x1 and the diameter d2 of the center of mass x2 can be determined. The distance b between the centroids x1 and x2 can be calculated.

[0081] The configuration of the ablation device can be determined based on the diameter d1, the diameter d2, and the distance b, and the orientation of the ablation device can be defined using the centroids x1 and x2. In particular, given a set of known deployment configurations of an ablation device {F i} (where index i marks the configuration), where each known unfolded configuration has a corresponding parameter {d 1,i ,d 2,i ,b i}, then the closest configuration {F* i For example, the minimum error or cost S can be found by using the following formula i The configuration is used to calculate:

[0082] S i =(d 1,i -d1) 2 +(d 2,i -d2) 2 +(b i -b) 2

[0083] In embodiments where the local ablation catheter device does not include an electromagnetic sensor, the device orientation may be defined in part by a unit vector v as follows:

[0084]

[0085] Furthermore, the unit vector w=(p1-x1) / |p1-x1| from the centroid x1 of the proximal electrode on the reference rack (e.g., the first rack) to the centroid p1 can fully define the device orientation together with v. The device configuration and device orientation obtained above can provide improved spatial positioning of each device electrode.

[0086] Optionally, the device positioning and / or tracking systems described herein may be used to construct (e.g., simulate) the surface anatomy of a heart chamber. Fig. 9B As depicted in FIG. 1 , at (950), the local catheter device can be navigated to different locations in the heart chamber, and at (952), based on the intracardiac ECG recording from the catheter electrode, one or more electrodes in contact with the tissue surface at any time can be determined (e.g., based on ECG amplitude, timing, or other criteria). After determining those one or more electrodes in contact with the tissue surface, at (954), discrete electrode locations of those one or more electrodes can be determined based on the device geometry and the sensed locations, as described above with reference to FIG. Figure 3 and Fig. 9A Described. Electrode positioning can be acquired as points for an anatomical structure map or surface reconstruction. When the device is navigated to various locations at the endocardial cavity surface, a multiplicity of such points (e.g., the positioning of the electrode in contact with the tissue surface) or a point cloud can be acquired to form the basis of a tissue map. In some embodiments, at (956), a tissue map can be generated. For example, at (954), a point cloud comprising multiple points can be generated, wherein each point from the multiple points corresponds to the positioning of an electrode identified at a different location from the multiple locations. At (956), the point cloud can be used to construct a map of the tissue surface.

[0087] Part of this representation (e.g., an organizational map) is Fig.10 , where a reconstruction of an endocardial anatomical surface is constructed using a point cloud (1000), the point cloud including points (1020) indicating the locations of one or more electrodes in contact with the tissue surface at multiple locations to which the ablation device is navigated. Based on these points, a surface triangulation or mesh can be used to generate a surface rendering, including light and shadow effects, perspective, etc.

[0088] In some embodiments, an anatomical map of the heart chambers may be acquired using other devices (e.g., imaging devices, etc.), and the anatomical map may be provided to the mapping and ablation system described herein. In such embodiments, the ablation device may optionally be used to confirm the accuracy of the anatomical map, e.g., using Fig. 9B Alternatively, 950-956 may be omitted and the system described herein may rely on anatomical maps provided by an external source.

[0089] Return to reference Fig. 9A , the method (900) further includes: determining an intended ablation region of the ablation device at (912), and presenting the intended ablation region (e.g., visually on a display) at (914). Optionally, a portion of the ablation device may also be presented with the intended ablation region. For example, an output device may display a visual representation of a mapping of the ablation device relative to the tissue surface based on the position and orientation of the ablation device. Fig.10 A distal portion (1050) of a local ablation catheter device is shown, including a rack basket proximate to or located at the endocardial surface (1010). Fig.10 Further depicted is an intended ablation zone (1030) displayed on the surface reconstruction (1000), which corresponds to the positioning of a focal ablation device at the endocardial surface. The ablation zone (1030) has a center (1032), which may be positioned as described herein. Fig.11 and Fig.12 Depicted are respective ablation devices (1150, 1250) having positions and orientations determined relative to tissue surface maps (1110, 1210). Similarly, Fig.17 Further depicted is an intended ablation zone (1730) displayed on the surface reconstruction (1700), which corresponds to the positioning of a linear focal ablation device at the endocardial surface (1710). The ablation zone (1730) has a center (1732), which may be positioned as described herein. Fig.18 and Fig.19 Respective linear ablation devices (1850, 1950) are depicted having positions and orientations determined relative to tissue surface maps (1810, 1910).

[0090] In some embodiments, the expected ablation zone can be determined at a processor (e.g., processor (42, 142)) based on the position and orientation of the ablation device, as further described below. For example, the expected ablation zone can be determined by: determining the closest distance from the ablation device to the tissue surface; identifying a set of points within a predefined distance from the distal end of the ablation device from a plurality of points when the closest distance is less than a predefined value; determining the centroid of the set of points; determining a local tangent plane of the surface extending through the centroid; and determining the center of the expected ablation zone based on the position and orientation of the ablation device relative to the local tangent plane, the center representing the location of the tissue surface with the maximum ablation depth (e.g., the location of the surface centroid of the ablation zone). In addition, the expected ablation zone can be based on one or more pulse waveform parameters (e.g., voltage, duration, delay, number of pulses, number of pulse groups, etc.), which can modify, for example, the size and depth of the expected ablation zone.

[0091] To illustrate an example of determining the intended ablation area, Fig.11 and Fig.18 An ablation device (1150, 1850), such as a local ablation catheter and a linear local ablation catheter, is depicted at an endocardial surface represented by a point cloud, the point cloud including a multiplicity of points, including corresponding points (1120, 1820), respectively. As depicted, the ablation device (1120) can be in an inclined orientation and partially deployed (e.g., similar to Figure 5 and other figures described further below). Ablation device (1850) may be in a tilted orientation, similar to ablation device (1120). Fig.11 and Fig.18 1852). Based on the current positioning of the distal tip (1152, 1852), and whether the closest distance from the device to the endocardial surface is less than a predefined interval, a local point set within a predefined distance D from the tip of the device in the point cloud can be identified by points (1120, 1820). For example, the predetermined interval can be less than about 4 mm, and the predefined distance can be less than about 3 cm. Although other points in the point cloud are not depicted, it is understood that the point cloud can include additional points (not depicted) that are not within the local point set.

[0092] The centroid (1122, 1822) of the local point set can be calculated. A local tangent plane (1110, 1810) of the surface passing through the local centroid (1122, 1822) is determined. For example, such a plane can be determined by solving an optimization problem. If the local point set (1120, 1820) is y i , the center of mass (1122,1822) is x c, and the unit normal of the local tangent plane (1110,1810) is n, then the distance from each local point to the tangent plane (1110,1810) is given by:

[0093] q i =(y i -x c )·n

[0094] The cost function can be defined as the sum of these squared distances:

[0095]

[0096] where the matrix A is defined as the sum of outer products (on a local set of points)

[0097]

[0098] In some embodiments, it is desirable to find the normal n of the local tangent plane that minimizes the cost C. Furthermore, since n is the unit normal, it satisfies the constraint n T n = 1. Introducing an appropriate Lagrange multiplier λ will lead to a constrained cost function:

[0099] C′=n T An-λ(n T n-1)

[0100] In some embodiments, C' can be minimized with respect to n and λ. For example, performing the minimization results in the eigenvalue equation:

[0101] An=λn

[0102] The unit eigenvector n* corresponding to the minimum eigenvalue of the matrix A is the desired solution of the normal to the local tangent plane (1110, 1810). Therefore, the local tangent plane (1110, 1810) is determined.

[0103] Once the local tangent plane is known, the ablation zone center (1130, 1830) can be determined based on known properties of the ablation zone (and its center), depending on the orientation of the distal device geometry relative to the local tangent plane and / or the deployed configuration. Thereafter, for a given device positioning or placement at the endocardial surface, the expected ablation zone can be rendered in the local tangent plane. In some embodiments, the expected ablation zone can be projected onto the surface rendering itself and depicted as one or more of a contour, a color patch, or other graphical indicator on the surface (e.g., projected or rendered in a map of the tissue, at (914)).

[0104] At (914), the intended ablation zone can be presented according to various methods. For example, a map of the tissue surface and a visual representation of the intended ablation zone in the map of the tissue surface can be displayed via an output device operably coupled to the processor (e.g., an input / output device (48, 148) or an output device coupled to an external computing device).

[0105] In some embodiments, an expected ablation zone can be determined (e.g., at a processor including, for example, processor (42, 142)) by: identifying an electrode from a plurality of electrodes in contact with a tissue surface (e.g., using ECG data, as described above); identifying an expected ablation zone shape from a plurality of expected ablation zone shapes based on a position and orientation of an ablation device; and generating, based on the expected ablation zone shape, an expected ablation zone having a center at a location corresponding to the electrode location, the center representing a location of the tissue surface having a maximum ablation depth (e.g., the location of a surface centroid of the ablation zone). For example, Figure 4 An illustration of an ablation device (430) (e.g., a local ablation catheter) in contact with a tissue region (410) and a simulated or intended ablation region (440) to be generated by pulsed electric field ablation is provided. The tissue region (410) interfaces with a blood pool (420) at a tissue wall surface or blood-tissue interface (412) where a catheter device (430) in the form of a partially deployed local ablation catheter is deployed. Figure 4 The distal portion of the device has a Figure 2A-2B The device (430) is in the form of a rack basket, and the device (430) engages the tissue interface (412) in a perpendicular or normal orientation relative to the blood-tissue interface (412). The device (430) can be configured to generate a pulsed electric field (indicated by a field profile (441)) that can produce an intended ablation zone (440) via irreversible electroporation. The intended ablation zone (440) is centered (or has a maximum depth) at a tissue surface or interface location (442), which in this case corresponds to the location of the distal end of the catheter device (430).

[0106] The shape, size, and / or orientation of the intended ablation zone (440) can be based on the spatial characteristics or geometry of the ablation device. For example, a linear local device can have an ablation zone whose shape and size can generally be different from the shape and size of a focal ablation device. In some embodiments, the ablated zone generated by the ablation device (430) can be recorded for the ablation device (430) when the device is in multiple positions, orientations, and / or configurations relative to the tissue surface, and the resulting shape of the generated ablated zone can be recorded and stored for reference when generating the intended ablation zone in the future. In some embodiments, such ablated zone can be generated in an experimental environment, for example, using a test subject / preclinical animal model.

[0107] exist Figure 5-Figure 8 and Figure 14-16 Depicted and referenced in Figure 5-Figure 8 and Figure 14-16 Further examples of intended ablation zones are described to illustrate variations in the intended ablation zone depending on the spatial characteristics of the ablation device. Figure 5 An illustration of an ablation device (530) in contact with a tissue region (510) and a simulated or intended ablation region (540) to be generated by pulsed electric field ablation is provided. The tissue region (510) interfaces with a blood pool (520) at a tissue wall surface or blood-tissue interface (512) where a catheter device (530) in the form of a partially deployed local ablation catheter is deployed. Figure 5 In the embodiment, the distal portion of the device has Figure 2A-2B , and the device engages the tissue interface in an oblique orientation relative to the blood-tissue interface (512). The device (530) can be configured to generate a pulsed electric field (indicated by the field profile (541)) that can produce an intended ablation zone (540) via irreversible electroporation. The intended ablation zone (540) is centered (or has a maximum depth) at a tissue surface or interface location (542), which in this case corresponds to the location of the most distal electrode of the catheter device (530) closest to the tissue wall interface (512).

[0108] Figure 6 An illustration of an ablation device (630) in contact with a tissue region (610) and a simulated or intended ablation region (640) to be generated by pulsed electric field ablation is provided. The tissue region (610) interfaces with a blood pool (620) at a tissue wall surface or blood-tissue interface (612) where a catheter device (630) in the form of a partially deployed local ablation catheter is deployed. Figure 6 The distal portion of the device has a Figure 2A-2B The device (630) may be in the form of a rack basket, and the device (630) engages the tissue interface (612) in a parallel orientation relative to the blood-tissue interface (612). The device (630) may be configured to generate a pulsed electric field (indicated by the field profile (641)) that may produce a desired ablation region (640) via irreversible electroporation. Figure 6 As shown, the ablation zone (640) is centered (or has a maximum depth) at a tissue surface or interface location (612), which in this case corresponds to the location of the proximal edge of the distal electrode of the catheter device (630) that is closest to the tissue wall interface (612).

[0109] Figure 7An illustration of an ablation device (730) in contact with a tissue region (710) and a simulated or intended ablation region (740) to be generated by pulsed electric field ablation is provided. The tissue region (710) interfaces with a blood pool (720) at a tissue wall surface or blood-tissue interface (712) where a catheter device (730) in the form of a partially deployed local ablation catheter is deployed. Figure 7 In the embodiment of the present invention, the distal portion of the fully deployed device (730) has the form of a rack basket, and the device engages the tissue interface (712) in a perpendicular or normal orientation relative to the blood-tissue interface (712). The device (730) can be configured to generate a pulsed electric field (indicated by the field profile (741)) that can produce a desired ablation area (740) via irreversible electroporation. Figure 7 As shown in , the ablation zone (740) is centered (or has a maximum depth) at the tissue surface or interface location (712), which in this case corresponds to the location of the distal tip of the catheter device (730).

[0110] Figure 8 An illustration of an ablation device (830) in contact with a tissue region (810) and a simulated or intended ablation region (840) to be generated by pulsed electric field ablation is provided. The tissue region (810) interfaces with a blood pool (820) at a tissue wall surface or blood-tissue interface (812) where a catheter device (830) in the form of a partially deployed local ablation catheter is deployed. Figure 8 In the embodiment of the present invention, the distal portion of the fully deployed device (830) has the form of a rack basket, and the device engages the tissue interface (812) in an oblique orientation relative to the blood-tissue interface (812). The device (830) can be configured to generate a pulsed electric field (indicated by the field profile (841)) that can produce a desired ablation area (840) via irreversible electroporation. Figure 8 As shown in , the ablation zone (840) is centered (or has a maximum depth) at a tissue surface or interface location (842), which in this case corresponds to the location on the tissue surface closest to the distal end of the catheter device (830).

[0111] Fig.14 An illustration of an ablation device (1430) (e.g., a linear localized ablation catheter) in contact with a tissue region (1410) and a simulated or expected ablation region (1440) to be generated by pulsed electric field ablation is provided. The tissue region (1410) interfaces with a blood pool (1420) at a tissue wall surface or blood-tissue interface (1412) where the linear catheter device (1430) is positioned. Fig.14In one embodiment, the distal portion of the device (1430) engages the tissue interface (1412) in an orientation perpendicular or normal to the blood-tissue interface (1412). The device (1430) can be configured to generate a pulsed electric field that can produce an intended ablation zone (1440) via irreversible electroporation. The intended ablation zone (1440) is centered (or has a maximum depth) at a tissue surface or interface location (1442), which in this case corresponds to the location of the distal end of the catheter device (1430).

[0112] The linear focal ablation device (1430) may include a set of annular electrodes arranged on a distal portion of the device (1430). For example, the device (1430) may include a set of proximal electrodes (1432) and a set of distal electrodes (1434). In some embodiments, the device (1430) may include a distal cap electrode (1436) (e.g., the most distal electrode). The set of electrode parameters defining the electrode geometry may include one or more of the length and diameter of the electrode and the spacing distance between adjacent electrodes. In some embodiments, the linear ablation device (1430) may include one or more sensors. For example, the distal portion of the device (1430) may include a sensor configured to receive an electromagnetic signal to measure one or more of the position and / or orientation of the distal portion of the device (1430), as described in more detail herein.

[0113] The shape, size and / or orientation of the expected ablation zone (1440) can be based on the spatial characteristics or geometry of the ablation device. For example, a linear local device can have an ablation zone whose shape and size can generally be different from the shape and size of a focal ablation device having a basket shape. In some embodiments, when the device is in multiple positions, orientations and / or configurations relative to the tissue surface, the ablated zone generated by the ablation device (1430) can be recorded for the ablation device (1430), and the resulting shape of the generated ablated zone can be recorded and stored for future reference when generating the expected ablation zone. In some embodiments, such an ablated zone can be generated in an experimental environment, for example, using a test subject / preclinical animal model. Additionally or alternatively, such an ablated zone shape can be derived from a computational model.

[0114] Fig.15 An illustration of an ablation device (1530) in contact with a tissue region (1510) and a simulated or intended ablation region (1540) to be generated by pulsed electric field ablation is provided. The tissue region (1510) interfaces with a blood pool (1520) at a tissue wall surface or blood-tissue interface (1512) where a catheter device (1530) in the form of a linear localized ablation catheter is disposed. Fig.15, the distal portion of the device engages the tissue interface (1512) in an oblique orientation relative to the blood-tissue interface. The device (1530) can be configured to generate a pulsed electric field that can produce an intended ablation zone (1540) via irreversible electroporation. The intended ablation zone (1540) is centered (or has a maximum depth) at a tissue surface or interface location (1542), which in this case approximately corresponds to the location of the most distal electrode of the catheter device (1530) that is closest to the tissue wall interface (1512).

[0115] Fig.16 An illustration of an ablation device (1630) in contact with a tissue region (1610) and a simulated or expected ablation region (1640) to be generated by pulsed electric field ablation is provided. The tissue region (1610) interfaces with a blood pool (1620) at a tissue wall surface or blood-tissue interface (1612) where a linear catheter device (1630) is positioned. Fig.16 In the embodiment of the present invention, the distal portion of the device (1630) engages the tissue interface (1612) in a substantially parallel orientation relative to the blood-tissue interface (1612). The device (1630) can be configured to generate a pulsed electric field that can produce a desired ablation area (1640) via irreversible electroporation. Fig.16 As shown in , the ablation zone (1640) is centered at a tissue surface or interface location (1612), which in this case corresponds to a location just proximal to the proximal edge of the distal electrode of the catheter device (1630).

[0116] like Figure 4-Figure 8 and Figure 14-16 As shown in , the ablation zone generated by the pulsed electric field can be centered at a tissue surface location (typically the endocardial surface of the cardiac tissue adjacent to the blood pool) and vary relative to the device geometry (e.g., typically based on the degree of deployment of the device and / or the orientation of the device relative to the local tissue interface). In some embodiments, the expected transmural ablation zone (where the ablated region of tissue extends continuously through the tissue thickness from the endocardial side to the epicardial side of the tissue) can exhibit a similar pattern.

[0117] In some embodiments, a representation of the ablation zone, such as a minimum expected ablation zone, can be graphically provided when a map of the tissue surface anatomy is available, with an estimated expected shape of the ablation zone (including the approximate center of the ablation zone) and its dependence on one or both of device deployment and device orientation relative to the local tissue wall.

[0118] Return to reference Fig. 9A, after determining and presenting the intended ablation area, at (916), the method (900) may wait for confirmation (e.g., from a user or a computing device) as to whether to deliver an ablation pulse. For example, a user may view the presented intended ablation area and determine whether the intended ablation area is suitable for treatment or requires further adjustment. The user may provide input indicating whether the tissue is to be ablated (e.g., via an input / output device (48, 148)). Alternatively or additionally, a computing device (e.g., a processor (42, 142)) may be programmed to evaluate the intended ablation area and, depending on whether the intended ablation area satisfies certain parameters (e.g., a predetermined amount of overlap with a previously ablated area, e.g., for forming a continuous lesion), determine whether to proceed with ablation of the tissue. When ablation is not to be continued (e.g., because the intended ablation area requires adjustment and therefore further repositioning and / or reconfiguration of the ablation device is necessary), (916-No), the process may return to (904). In this case, the ablation device can be repositioned at (904), and / or reconfigured at (906), and the spatial characteristics of the device can be reevaluated to determine the expected ablation area after such adjustment of the ablation device. In some embodiments, the expected ablation area can be updated and displayed in real time, for example, on a tissue map of the target tissue surface. When ablation is to be continued (916-yes), at (918), the tissue can be ablated by the ablation device and the ablated area is presented (e.g., on a tissue map).

[0119] In some embodiments, a mapping system (e.g., mapping system (10, 140)) separate from a signal generator (e.g., pulse waveform generator (130)) can send a signal to the signal generator to cause the signal generator to generate a pulse waveform for delivery to the ablation device, so that the ablation device generates an electric field that produces an ablated area corresponding to the intended ablation area. In some embodiments, the mapping system can be integrated with the signal generator, and when it is determined that ablation is to proceed, the mapping system can generate a pulse waveform and deliver it to the ablation device. As described in more detail herein, Fig.12 and Fig.13 Ablation areas (1220, 1222, 1224, 1320, 1322, 1324, 1326) on the tissue surface (1210, 1310) are depicted.

[0120] In some embodiments, the systems, devices, and methods described herein can base the ablated region on the expected ablation region (e.g., making the ablated region the same as the expected ablated region). Thus, after ablating the tissue, at (918), such systems, devices, and methods can present the ablated region by changing the representation of the expected ablation region to convey that the region has been ablated. For example, the expected ablation region can be visually depicted using a first marking or color set before ablation, and the ablated region can be visually depicted using a second marking or color set that is different from the first marking or color set after ablation.

[0121] In some embodiments, the systems, devices, and methods may use further methods to detect tissue areas that have been ablated (e.g., using signals (e.g., impedance) collected by one or more sensors (e.g., one or more electrodes (116, 122), receiver (118)), or using an external device). In such embodiments, the systems, devices, and methods may further adjust their methods (e.g., models, algorithms) to determine intended ablation areas based on the detected ablated areas. For example, analysis of intended ablation areas and how they are compared to actual ablated areas, as well as parameters associated with tissue and / or ablation devices (e.g., tissue thickness, tissue type, ablation device geometry and / or positioning, etc.) that may cause differences between intended ablation areas and actual ablation areas, can be used to improve future determination of intended ablation areas.

[0122] When delivery of ablative pulses has not yet been completed by the ablation device (e.g., when a continuous lesion line is generated using the ablation device, as described in reference Fig.12 Further described), at (920-No), the process can return to (904) so ​​that the ablation device can be navigated to another location and additional ablation pulses can be delivered. For example, when the ablation device is located at a second location different from the first location, the receiver can receive data representing the signal in response to the electric field or the magnetic field. The second position and second orientation of the ablation device can then be determined based on the data representing the signal. A second intended ablation area of ​​the ablation device in the tissue surface can be determined based on the second position and second orientation of the ablation device.

[0123] The visual representation of the ablated region can be displayed by the output device using a first set of markers, and the visual representation of the second intended ablation region can be displayed using a second set of markers different from the first set of markers. For example, as further described below, Fig.12 A first set of three ablated regions (1220, 1222, 1224) represented by a first set of markings (eg, solid lines) and a second intended ablation region (1230) represented by a second set of markings (eg, dashed lines) are shown.

[0124] In some embodiments, the first ablated region and the second ablated region may form part of a continuous lesion in the tissue surface. For example, the signal generator may be activated to generate a pulse waveform to deliver to the ablation device so that when the second intended ablation region has an overlapping area with the ablated region greater than a predetermined value, the ablation device generates a second ablated region corresponding to the second intended ablation region. Fig.12 and Fig.19 The process of generating a continuous lesion line using the systems and devices described herein (e.g., basket ablation device, linear ablation device) is shown. The distal device geometry in the form of a focal ablation device (1250, 1950) is shown at the endocardial surface (1210, 1910). The estimated ablation area (1230, 1930) for the current placement of the device (1250, 1950) is displayed on the endocardial surface (1210, 1910), Fig.12 and Fig.19 as a dashed outline. Fig.12 and Fig.19 , the previously ablated area (1220, 1222, 1224, 1920, 1922, 1924) is shown by a solid outline. If the placement and the intended ablation area have sufficient overlap with the previously ablated area (1220, 1222, 1224, 1920, 1922, 1924) as determined by the user, the user can ablate using the current device placement and mark the intended area as the ablated area, so the display can be updated to render the dashed outline as a solid outline instead of indicating completed ablation, as shown in FIG. Fig.13 and Fig. 20 In some embodiments, various other renderings of ablated regions and intended ablation regions may be used to visually distinguish the region types, including but not limited to different and distinctive colors, outlines, shading, transparency, or various graphic rendering methods that visually render intended ablation regions and ablated regions differently.

[0125] This process can continue to generate a series of overlapping ablated regions to generate a continuous lesion line. In some embodiments, the size of the depicted intended ablation region can be shown as smaller than the simulated or preclinically determined region size as a means of prescribing closer placement of adjacent ablations to ensure adequate lesion overlap. In addition, both the shape and size of the surface rendering of the ablation region can generally depend on the device orientation relative to the local cut plane and / or on the device deployment state. In some embodiments, the shape and size of the depicted ablation region can depend at least in part on the geometry of the distal device. For example, a linear focal ablation device can correspond to an ablation region that has a shape and size that is generally different from the shape and size of a focal ablation device having a basket shape.

[0126] When ablation is complete, (920-Yes), at (922), the ablation device can be removed from the heart chamber and the patient.

[0127] It should be understood that the examples and illustrations in the present disclosure are for illustrative purposes and deviations and variations, such as the number of racks, the number of electrodes, etc., or various focal ablation devices, such as linear ablation catheters, etc., may be constructed and deployed in accordance with the teachings herein without departing from the scope of the invention.

[0128] As used herein, the terms "about" and / or "approximately" when used in conjunction with numerical values ​​and / or ranges generally refer to numerical values ​​and / or ranges that are close to the numerical values ​​and / or ranges. In some cases, the terms "about" and "approximately" can mean within ±10% of the value. For example, in some cases, "about 100 [units]" can mean within 100 ± 10% (e.g., 90 to 110). The terms "about" and "approximately" can be used interchangeably.

[0129] Some embodiments described herein relate to computer storage products with non-transitory computer-readable media (also referred to as non-transitory processor-readable media) having instructions or computer code thereon for performing various computer-implemented operations. Computer-readable media (or processor-readable media) are non-transitory in the sense that they do not themselves contain temporary propagating signals (e.g., propagating electromagnetic waves that carry information on a transmission medium such as space or cables). The media and computer code (also referred to as code or algorithm) may be those designed and constructed for one or more specific purposes. Examples of non-transitory computer-readable media include, but are not limited to: magnetic storage media such as hard disks, floppy disks, and magnetic tapes; optical storage media such as compact discs / digital video discs (CD / DVD), compact disc read-only memories (CD-ROMs), and holographic devices; magneto-optical storage media such as optical discs; carrier signal processing modules; and hardware devices specifically configured for storing and executing program code, such as application specific integrated circuits (ASICs), programmable logic devices (PLDs), read-only memories (ROMs), and random access memory (RAM) devices. Other embodiments described herein relate to computer program products, which may contain instructions and / or computer code, such as those disclosed herein.

[0130] The systems, devices and / or methods described herein may be implemented by software (implemented on hardware), hardware or a combination thereof. A hardware module may include, for example, a general purpose processor (or microprocessor or microcontroller), a field programmable gate array (FPGA) and / or an application specific integrated circuit (ASIC). A software module (implemented on hardware) may be represented by a variety of software languages ​​(e.g., computer code), including C, C++, Ruby, Visual and / or other object-oriented, procedural or other programming languages ​​and development tools. Examples of computer code include, but are not limited to, microcode or microinstructions, machine instructions, such as those generated by a compiler, code for generating network services, and files containing high-level instructions executed by a computer using an interpreter. Additional examples of computer code include, but are not limited to, control signals, encrypted codes, and compressed codes.

[0131] The specific examples and descriptions herein are exemplary in nature and one skilled in the art may produce embodiments based on the teachings herein without departing from the scope of the present invention, which is limited only by the appended claims.

Claims

1. A device for visually displaying a desired ablation area, comprising: Memory; as well as a processor operably coupled to the memory, the processor being configured to: activating the field generator to generate an electric field or a magnetic field so that the signal can be received by a receiver coupled to an ablation device disposed adjacent to the tissue surface; obtaining processed data associated with the signal; determining a position and orientation of the ablation device based on the processed data; displaying, via an output device, a map of the tissue surface, the map of the tissue surface being composed of a plurality of points forming a point cloud; determining a minimum distance from the ablation device to the tissue surface; In response to the closest distance being less than a predefined value, identifying a set of points from the plurality of points that are within a predefined distance from a distal end of the ablation device; determining a centroid of the point set; determining a local tangent plane to the surface extending through the centroid; determining a center of an intended ablation zone based on the position and orientation of the ablation device relative to the local tangent plane, the center representing the location of a surface centroid of the ablation zone; and A visual representation of the intended ablation zone in the map of the tissue surface is displayed via the output device.

2. The device according to claim 1, wherein: The expected ablation area is a first expected ablation area, and the processor is further configured to: In response to the change in position or orientation of the ablation device, determining a second intended ablation region of the ablation device in the tissue surface; and A visual representation of an ablated region associated with a first intended ablation region in the map of the tissue surface and a visual representation of a second intended ablation region in the map of the tissue surface are displayed via the output device.

3. The apparatus of claim 2, wherein the processor is configured to display the visual representation of the ablated region and the visual representation of the second intended ablation region by: projecting the ablated region into a map of the tissue surface using a first set of markers; and The second intended ablation zone is projected into a map of the tissue surface using a second set of markers different from the first set of markers.

4. The device according to claim 1, wherein: The ablation device includes a rack set, wherein each rack of the rack set includes a proximal electrode set and a distal electrode set, such that the rack sets collectively include a plurality of proximal electrodes and a plurality of distal electrodes, and The processor is configured to determine the position and orientation of the ablation device by: determining a set of geometric parameters of the ablation device based on the processed data; determining a configuration of the ablation device based on the set of geometric parameters; and At least one of a position and an orientation of the ablation device is determined based on the determined configuration of the ablation device and the processed data.

5. The device according to claim 4, wherein: The processor is configured to determine an orientation of the ablation device at least by determining a longitudinal unit vector associated with the ablation device.

6. The device according to claim 4, wherein: The processor is configured to determine the orientation of the ablation device at least by identifying a deployment configuration that: (1) has an associated set of geometric parameters that most closely matches the determined set of geometric parameters; And (2) the deployment configuration is from a set of deployment configurations, each of which has an associated set of geometric parameters.

7. The device according to claim 6, wherein: The processor is configured to identify, by using a least squares method, a deployment configuration having an associated set of geometric parameters that most closely matches the determined set of geometric parameters.

8. The apparatus according to claim 1, further comprising an amplifier configured to amplify a signal received by the receiver, The processor is configured to obtain the processed data by digitizing and processing the signal amplified by the amplifier.

9. The device according to claim 1, wherein: The processor is further configured to display, via the output device, a visual representation of the ablation device based on the position and orientation of the ablation device.

10. The apparatus of claim 1, wherein the ablation device comprises a plurality of electrodes, The processor is further configured to: identifying an electrode in contact with the tissue surface from the plurality of electrodes, the center of the intended ablation zone being at a location corresponding to the location of the electrode; and An expected ablation zone shape is identified from a plurality of expected ablation zone shapes based on the position and orientation of the ablation device, the expected ablation zone having the expected ablation zone shape.

11. The device according to claim 1, wherein: The processor is further configured to construct a map of the tissue surface based on processed data associated with signals received by the receiver when the ablation device is navigated to a plurality of endocardial locations.

12. The device according to claim 1, wherein: The predefined value is less than 4 mm and the predefined distance is less than 3 cm.

13. The device according to any one of claims 1 to 12, wherein: The ablation device includes a plurality of racks configured to form a basket shape.

14. The device according to any one of claims 1 to 12, wherein: The ablation device includes a distal portion comprising a linear shape.

15. A method for visually displaying a desired ablation area, comprising: receiving, at a processor in the set of processors, data representing a signal received by a receiver coupled to an ablation device disposed adjacent a tissue surface, the receiver receiving the signal in response to an electric field or a magnetic field generated by a field generator; determining, at a processor in the set of processors, a position and an orientation of the ablation device based on data representing the signal; displaying, via an output device operatively coupled to a processor in a set of processors, a map of the tissue surface comprised of a plurality of points forming a point cloud; determining, at a processor in the set of processors, a closest distance from the ablation device to the tissue surface; In response to the closest distance being less than a predefined value, identifying, at a processor in the set of processors, a local set of points from the plurality of points that are within a predefined distance from a distal end of the ablation device; determining, at a processor in the set of processors, a local tangent plane for a surface based on the local point set; determining, at a processor in the set of processors, a center of a desired ablation zone based on a position and orientation of the ablation device relative to the local tangent plane; and A visual representation of the intended ablation zone in the map of the tissue surface is displayed via the output device.

16. The method according to claim 15, wherein: The signal is a first signal, and the method further comprises: receiving, at each of a plurality of locations to which the ablation device is navigated, data representing a second signal received by the receiver in response to an electric field or a magnetic field generated by the field generator, the ablation device comprising a plurality of electrodes; At each location from the plurality of locations, identifying at least one electrode from the plurality of electrodes in contact with the tissue surface based on at least one of: (i) data representing a second signal received by the receiver at the location; or (ii) electrocardiogram data recorded from the electrode; generating a point cloud comprising a plurality of points, wherein each point from the plurality of points corresponds to a location of at least one electrode identified at a different location from the plurality of locations; and A map of the tissue surface is constructed using the point cloud.

17. The method of claim 15, wherein: The ablation device comprises a gear rack set, wherein each gear rack of the gear rack set comprises a proximal electrode set and a distal electrode set, such that the gear rack sets collectively comprise a plurality of proximal electrodes and a plurality of distal electrodes, Determining the position and orientation of the ablation device includes: determining a set of geometric parameters of the ablation device based on received data representing the signal; determining a configuration of the ablation device based on the set of geometric parameters; and At least one of a position or an orientation of the ablation device is determined based on the determined configuration of the ablation device and the received data representative of the signal.

18. The method of claim 15, further comprising displaying, via the output device, a visual representation of a map of the ablation device relative to the tissue surface based on the position and orientation of the ablation device.

19. A system for generating an ablation zone based on an intended ablation zone, comprising: a field generator configured to generate an electric field or a magnetic field; a signal generator configured to generate a pulse waveform for ablating tissue; Output devices; as well as a processor operably coupled to the field generator, the signal generator, and the output device, the processor being configured to: activating the field generator to generate the electric or magnetic field such that a signal is received by a receiver coupled to an ablation device disposed adjacent a tissue surface; obtaining processed data associated with the signal; determining a position and orientation of the ablation device based on the processed data; causing the output device to display a map of the tissue surface, the map of the tissue surface being composed of a plurality of points forming a point cloud; determining a minimum distance from the ablation device to the tissue surface; In response to the closest distance being less than a predefined value, identifying a local set of points from the plurality of points that are within a predefined distance from a distal end of the ablation device; Determining a local tangent plane of the surface based on the local point set; and determining a center of a desired ablation zone based on the position and orientation of the ablation device relative to the local tangent plane; causing the output device to display a visual representation of the intended ablation zone in a map of the tissue surface; and In response to the expected ablation zone corresponding to the desired ablation zone, a signal generator is activated to generate a pulse waveform for delivery to the ablation device such that the ablation device produces an ablated zone corresponding to the expected ablation zone.

20. The system of claim 19, wherein: The field generator comprises a set of electrode patches which generate one or more electric fields, the electric or magnetic fields comprising the one or more electric fields generated by the set of electrode patches.

21. The system of claim 19, wherein: The field generator comprises a set of transmitter coils, wherein each transmitter coil generates a time-varying magnetic field, and the electric or magnetic field comprises the time-varying magnetic field generated by the set of transmitter coils.

22. The system of claim 19, wherein: The processor is further configured to: In response to activating the signal generator, the output device is caused to change the visual representation of the intended ablation zone to indicate that the intended ablation zone is ablated.

23. The system of claim 19, wherein: The ablation device includes a rack set, wherein each rack of the rack set includes a proximal electrode set and a distal electrode set, such that the rack sets collectively include a plurality of proximal electrodes and a plurality of distal electrodes, and The processor is configured to determine the position and orientation of the ablation device by: determining a set of geometric parameters of the ablation device based on the processed data; determining a configuration of the ablation device based on the set of geometric parameters; and At least one of a position or an orientation of the ablation device is determined based on the determined configuration of the ablation device and the processed data.

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