Visualizing pulse field ablation (PFA) tags using signed distance functions

Abstract

Systems and methods for visualization of pulsed field ablation tags are disclosed. In some implementations, a system includes a device including a processor in communication with one or more sensors and a catheter including a plurality of electrodes. In some implementations, the processor is configured to: receive, via the one or more sensors, a location of each of the plurality of electrodes within a three-dimensional environment during a first ablation session; for the first ablation session, calculating a first implicit function representing an energy field of the first ablation session from the received position of each of the plurality of electrodes; and presenting, via a display, a first volumetric representation of the calculated first implicit function.

Description

[0001] Related Applications

[0002] This application claims the benefit and priority of a partial continuation application of U.S. Non - Provisional Patent Application No. 18 / 081,486, entitled "Using Signed Distance Functions to Visualize Pulsed Field Ablation", filed on December 14, 2022, the entire content of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to systems and methods for tracking and visualizing invasive medical treatments. More specifically, the present invention relates to systems and methods for visualizing pulsed field ablation (PFA) tags using signed distance functions. Background Art

[0004] During pulsed field ablation (PFA), electrodes of a single - electrode catheter or a multi - electrode catheter (such as the VARIPULSE multi - electrode catheter manufactured by Biosense Webster, Inc., Irvine, California) are activated to disrupt electrical pathways in tissue by forming non - conductive ablation lesions. During the procedure, these electrodes may be activated multiple times, and each activation is sometimes referred to as an ablation session. Due to the number of activations and, for multi - electrode catheters, the number of electrodes, it may be difficult for a physician to understand the effect of one or more ablation sessions. Specifically, while the positions of the activated electrodes of the catheter can be recorded and displayed as a point cloud or multiple tags or markers in three - dimensional space, such displays do not indicate the ablation field energy received by the tissue. Additionally, the energy from the electric field between the electrodes is not represented. This can be important, especially in multiple ablation sessions, as energy accumulates in the tissue. Furthermore, the point cloud representation may not clearly distinguish between different ablation sessions or clearly indicate that two points or tags were created from the same ablation session. Summary of the Invention

[0005] Specific embodiments of the systems and methods described herein solve these and other problems by representing each ablation session as a combination of adjacent implicit functions. In some specific embodiments, the energy field between adjacent electrodes can be represented by a signed distance function. In many specific embodiments, the adjacent implicit functions are smoothly connected, thereby improving the representability of the energy field received by a single catheter ablation session. In some specific embodiments, the implicit functions can be rendered into a display within a three - dimensional environment via volume tracking. In some specific embodiments, shading or color can be utilized to show the accumulated energy across multiple ablation sessions (e.g., darker regions indicate more accumulated energy, while lighter regions indicate lower accumulated energy, or vice versa).

[0006] According to an exemplary embodiment, a system for visualizing a pulsed field ablation label is provided. In an embodiment, the system includes an apparatus that includes a processor and a catheter, the processor being in communication with one or more sensors, and the catheter including a plurality of electrodes. In an embodiment, the processor is configured to: during a first ablation session, receive, via the one or more sensors, the position of each of the plurality of electrodes within a three-dimensional environment; for the first ablation session, calculate a first implicit function representing the energy field of the first ablation session based on the received position of each of the plurality of electrodes; and present, via a display, a first volumetric representation of the calculated first implicit function.

[0007] In some embodiments, the processor is further configured to calculate the first implicit function via a signed distance function based on the positions of a pair of adjacent electrodes among the plurality of electrodes during the first ablation session. In another embodiment, the processor is further configured to calculate the implicit function via a plurality of signed distance functions, each signed distance function corresponding to a different pair of adjacent electrodes. In some embodiments, the processor is further configured to, for each voxel of a plurality of voxels of the three-dimensional environment, calculate the distance from the voxel to the position of an electrode among the plurality of electrodes. In another embodiment, the processor is further configured to, for each voxel of a plurality of voxels of the three-dimensional environment, determine whether a corresponding calculated distance is less than a threshold. In yet another embodiment, the processor is further configured to, for one or more voxels of a plurality of voxels of the three-dimensional environment, modify a value associated with the voxel in response to the corresponding calculated distance being less than the threshold. In yet another embodiment, the processor is further configured to modify a value associated with a first voxel in response to the distance from the first voxel to the position of an electrode among the plurality of electrodes being less than the threshold during a first ablation session; and modify the value associated with the first voxel in response to the distance from the first voxel to the position of an electrode among the plurality of electrodes being less than the threshold during a second ablation session. In yet another embodiment, the processor is further configured to present the first volumetric representation as one or more voxels in the three-dimensional environment, each voxel being shaded based on the value associated with the voxel. In yet another embodiment, the processor is further configured to: during a second ablation session, receive, via the one or more sensors, the position of each of the plurality of electrodes; for the second ablation session, calculate a second implicit function representing the energy field of the second ablation session; and present, via a display, a second volumetric representation of the calculated second implicit function and the first volumetric representation of the calculated first implicit function. In some embodiments, the processor is further configured to: during a first ablation session, classify the position of each of the plurality of electrodes into a plurality of clusters; and for the first ablation session, calculate the first implicit function via a signed distance function between paired electrodes within each cluster.

[0008] In another aspect, a method for visualizing a pulsed field ablation label is provided. The method includes, during a first ablation session, receiving, by a processor of a device, the position of each of a plurality of electrodes of a catheter within a three-dimensional environment from one or more sensors; for the first ablation session, calculating, by the processor, a first implicit function representing an energy field of the first ablation session based on the received positions of each of the plurality of electrodes; and presenting, by the processor via a display, a first volume representation of the calculated first implicit function.

[0009] In some embodiments, the method includes calculating the first implicit function via a signed distance function based on the positions of a pair of adjacent electrodes among the plurality of electrodes during the first ablation session. In another embodiment, the method includes calculating the implicit function via a plurality of signed distance functions, each signed distance function corresponding to a different pair of adjacent electrodes.

[0010] In some embodiments, the method includes, for each of a plurality of voxels of the three-dimensional environment, calculating a distance from the voxel to the position of an electrode among the plurality of electrodes. In another embodiment, the method includes, for each of a plurality of voxels of the three-dimensional environment, determining whether a corresponding calculated distance is less than a threshold. In yet another embodiment, the method includes, for one or more of the plurality of voxels of the three-dimensional environment, modifying a value associated with the voxel in response to the corresponding calculated distance being less than the threshold. In yet another embodiment, the method includes modifying a value associated with a first voxel in response to a distance from the first voxel to the position of an electrode among the plurality of electrodes during a first ablation session being less than the threshold; and modifying the value associated with the first voxel in response to a distance from the first voxel to the position of the electrode among the plurality of electrodes during a second ablation session being less than the threshold. In yet another embodiment, the method includes presenting, by the processor, the first volume representation as one or more voxels in the three-dimensional environment, each voxel being shaded based on the value associated with the voxel. In another embodiment, the method includes, during a second ablation session, receiving the position of each of the plurality of electrodes from one or more sensors; for the second ablation session, calculating a second implicit function representing an energy field of the second ablation session; and presenting via the display a second volume representation of the calculated second implicit function and the first volume representation of the calculated first implicit function. In another embodiment, the method includes, during a first ablation session, classifying the positions of each of the plurality of electrodes into a plurality of clusters; and for the first ablation session, calculating the first implicit function via a signed distance function between pairs of electrodes within each cluster.

[0011] According to one or more embodiments, the above-described exemplary method embodiments may be implemented as a device, a system, and / or a computer program product. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] This patent or patent application document contains at least one drawing executed in color. After a request has been made and the necessary fees are paid, the United States Patent and Trademark Office will provide a copy of this patent or patent application publication with color drawings.

[0013] A more detailed understanding can be obtained from the following detailed description in conjunction with the accompanying drawings by way of example, in which like reference numerals in the drawings indicate like elements, and in which:

[0014] Figure 1 depicts an example catheter-based electrophysiological mapping and ablation system in accordance with one or more embodiments;

[0015] Figure 2 is a block diagram of an example system for remotely monitoring and transmitting patient biometrics in accordance with one or more embodiments;

[0016] Figure 3 is a system diagram of an example of a computing environment in communication with a network in accordance with one or more embodiments;

[0017] Figures 4A to 4D is an illustration of an example electroanatomical map of cardiomyopathy;

[0018] Figure 5A depicts an example of a linear catheter including a plurality of electrodes in accordance with one or more embodiments;

[0019] Figure 5B depicts an example of a balloon catheter having a plurality of electrodes in accordance with one or more embodiments;

[0020] Figure 5C depicts an example of a collar catheter having a plurality of electrodes in accordance with one or more embodiments;

[0021] Figure 6A is a screenshot of an example of a point cloud generated by a plurality of ablation sessions in accordance with one or more embodiments;

[0022] Figure 6B is a screenshot of an example of volume tracking of a plurality of implicit functions generated by a plurality of ablation sessions in accordance with one or more embodiments;

[0023] Figure 6C is an illustration of an example energy field around a plurality of electrodes during an ablation session in accordance with one or more embodiments;

[0024] Figure 6D is in accordance with one or more embodiments representing Figure 6C an illustration of an example signed distance function of an energy field around a plurality of electrodes during an ablation session of;

[0025] Figure 6E is according to one or more embodiments Figure 6B A screenshot of an example of volume tracking of multiple implicit functions, where the highlighted implicit function corresponds to one ablation session among multiple ablation sessions;

[0026] Figure 7 is a flowchart of a method for visualizing pulsed field ablation tags according to one or more embodiments;

[0027] Figure 8A and Figure 8B are screenshots of examples of point clouds and volume tracking respectively generated by multiple ablation sessions according to one or more embodiments;

[0028] Figure 8C is an illustration of an example of ablation tags in a three-dimensional space according to one or more embodiments;

[0029] Figure 8D is according to one or more embodiments in Figure 8C An illustration of an example of a tracking path between ablation tags in a three-dimensional space;

[0030] Figure 8E and Figure 8F is an illustration of an example of volume tracking of multiple implicit functions in a three-dimensional space from different perspectives according to one or more embodiments;

[0031] Figure 8G is an illustration of an example of volume tracking with adjustable function parameters according to one or more embodiments; and

[0032] Figure 9 is a flowchart of a method for rendering volume tracking generated by multiple ablation sessions according to one or more embodiments. DETAILED DESCRIPTION

[0033] During pulsed field ablation (PFA), the electrodes of a single-electrode catheter or a multi-electrode catheter are activated to disrupt the electrical pathways in tissue by forming non-conductive ablation lesions. During the procedure, these electrodes can be activated multiple times, and each activation is sometimes referred to as an ablation session. To provide visual feedback to the physician, some systems track the position of the electrodes during each ablation session and provide a visualization of points or markers (sometimes referred to as tags or ablation tags) in a three-dimensional environment (e.g., representing tissue, blood vessels, or other environments where the catheter is placed).

[0034] Due to the number of activations and, for multi-electrode catheters, the number of electrodes, it may be difficult for a physician to understand the effect of one or more ablation sessions. In many embodiments, the point cloud may not identify the ablation field energy received by the tissue. Additionally, the energy from the electric field between electrodes is not represented in many implementation realizations. This can be important, especially in multiple ablation sessions, as energy accumulates in the tissue. Further, the point cloud representation may not clearly distinguish different ablation sessions or clearly indicate that two points or labels were created from the same ablation session.

[0035] Systems and methods for visualizing pulse field ablation tags or markers are disclosed herein. More specifically, the present invention relates to using implicit functions to represent the energy field during an ablation session from multiple electrodes. In some embodiments, the implicit function may include a combination or aggregation of signed distance functions between adjacent pairs of electrodes. In many embodiments, a smooth minimum function may be used to determine the energy field between adjacent electrodes during ablation. Determining the energy field may include, in some implementations, calculating the intensity or amplitude of the field at different points, or may include, in other embodiments, estimating or approximating the amplitude of the field. For example, in some implementations, visualization of the energy field may not require exact values, and approximations may be sufficient to use while being faster to compute and consuming fewer resources, etc. The distance from points in the environment (e.g., represented by voxels) to one or more electrodes may be used to approximate the energy field in many implementations.

[0036] For example, in some implementations, the energy field may be determined based on electrode positions, and an energy threshold that may be considered sufficient for ablation may be assigned or determined. In some implementations, the energy field values may be converted to distances such that the distance at the provided threshold is zero. Distance values may then be assigned to the associated volume such that energy below the threshold produces a positive distance and energy above the threshold has a negative distance. These distance values can then be easily rendered as a volume cloud or region within a three-dimensional environment for viewing.

[0037] In other implementations using approximations, a smooth function (such as a smooth minimum function) that approximates the energy field at a given threshold may be determined. This function may be rendered as a surface, resulting in a similar visualization while significantly reducing the processing requirements.

[0038] In many implementations, one or more ablation sessions may be rendered as a volume trace within a three-dimensional environment. The accumulated energy during multiple ablation sessions may be calculated and displayed via the shadow, translucency, or color of the volume trace. While many of the examples discussed herein are with respect to the heart, any anatomical structure, body part, organ, or portion thereof may be the target of ablation and visualization.

[0039] Advantageously, implicit functions require lower processing resources and memory to render while still providing high-quality visualization because they use less three-dimensional data for the same or better visual fidelity. For example, each ablation session can be represented by a single aggregated implicit function with smooth boundaries, which requires fewer resources than storing a three-dimensional bitmap or array with exact values for each location or voxel within the environment.

[0040] Reference Figure 1 , which shows an example system shown as system 10 (e.g., medical device equipment and / or catheter-based electrophysiological mapping and ablation), where one or more features of the subject matter herein can be implemented according to one or more embodiments. As shown, system 10 includes a recorder 11, a heart 12, a catheter 14, a model or anatomical map 20, an electrogram 21, a spline 22, a patient 23, a physician 24 (or medical professional or clinician), a position pad 25, an electrode 26, a display device 27, a distal tip 28, a sensor 29, a coil 32, a patient interface unit (PIU) 30, an electrode skin patch 38, an ablation energy generator 50, and a workstation 55. It should also be noted that each element and / or item of system 10 represents one or more of that element and / or that item. Figure 1 The example of system 10 shown can be modified to implement the embodiments disclosed herein. The embodiments disclosed herein can be similarly applied using other system components and settings. Additionally, system 10 can include additional components such as elements for sensing electrical activity, wired or wireless connectors, processing and display devices, and the like.

[0041] System 10 includes a plurality of catheters 14 that are inserted by a physician 24 through the patient's vascular system via the skin into the chambers or vascular structures of the heart 12. Generally, a delivery sheath catheter is inserted into the left atrium or right atrium near the desired location within the heart 12. Then, a plurality of catheters can be inserted into the delivery sheath catheter to reach that desired location. The plurality of catheters 14 can include catheters dedicated to sensing intracardiac electrogram (IEGM) signals, catheters dedicated to ablation, and / or catheters dedicated to both sensing and ablation. An example catheter 14 configured for sensing IEGM is shown herein. The physician 24 places the distal tip 28 of the catheter 14 in contact with the heart wall for sensing a target site within the heart 12. For ablation, the physician 24 would similarly bring the distal end of the ablation catheter to the target site for ablation.

[0042] Catheter 14 is an exemplary catheter that includes one (preferably multiple) electrodes 26 optionally distributed on a plurality of splines 22 at the distal end 28 and configured to sense IEGM signals. Additionally, catheter 14 may further include a sensor 29 embedded in or near the distal end 28 for tracking the position and orientation of the distal end 28. Optionally and preferably, the position sensor 29 is a magnetic-based position sensor that includes three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0043] The sensor 29 (e.g., a location- or magnetic-based sensor) can operate with a position pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field in a predefined workspace. The real-time position of the distal end 28 of catheter 14 can be tracked based on the magnetic field generated by the position pad 25 and sensed by the sensor 29. Details of magnetic-based position sensing techniques are described in U.S. Pat. Nos. 5,539,199, 5,443,489, 5,558,091, 6,172,499, 6,239,724, 6,332,089, 6,484,118, 6,618,612, 6,690,963, 6,788,967, and 6,892,091, which are incorporated herein by reference.

[0044] System 10 includes one or more electrode patches 38 positioned to contact the skin of patient 23 to establish a position reference for impedance-based tracking of the position pad 25 and the electrodes 26. For impedance-based tracking, current is directed toward the electrodes 26 and sensed at the patches 38 (e.g., electrode skin patches) such that the position of each electrode can be triangulated via the patches 38. Details of impedance-based position tracking techniques are described in U.S. Pat. Nos. 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182, which are incorporated herein by reference.

[0045] Recorder 11 displays an electrogram 21 captured with electrodes 18 (e.g., body surface electrocardiogram (ECG) electrodes) and an intracardiac electrogram (IEGM) captured with the electrodes 26 of catheter 14. Recorder 11 may include pacing capabilities for pacing the heart rhythm and / or may be electrically connected to an independent pacemaker.

[0046] System 10 may include an ablation energy generator 50 adapted to conduct ablation energy to one or more of the electrodes 26 at the distal end 28 of a catheter 14 configured for ablation. The energy generated by the ablation energy generator 50 may include, but is not limited to, radiofrequency (RF) energy or pulsed field ablation (PFA) energy (including monopolar or bipolar high voltage DC pulses that can be used to effect irreversible electroporation (IRE)), or a combination thereof.

[0047] The PIU 30 is an interface configured to establish electrical connectivity between the catheter, electrophysiology equipment, power supply, and a workstation 55 for controlling the operation of the system 10. The electrophysiology equipment of the system 10 may include, for example, a plurality of catheters 14, position pads 25, body surface ECG electrodes 18, electrode patches 38, an ablation energy generator 50, and a recorder 11. Optionally and preferably, the PIU 30 further includes processing capabilities for performing real-time calculations of the position of the catheter and for performing ECG calculations.

[0048] The workstation 55 includes a memory, a processor unit with a memory or storage device loaded with appropriate operating software, and user interface capabilities. The workstation 55 may provide a plurality of functions, optionally including: (1) performing three-dimensional (3D) modeling of the endocardial anatomy and rendering a model or anatomical map 20 for display on a display device 27; (2) on the display device 27, displaying the activation sequence (or other data) compiled from the recorded electrograms 21 as representative visual markers or images superimposed on the rendered anatomical map 20; (3) displaying the real-time position and orientation of a plurality of catheters within the heart chambers; and (5) on the display device 27, displaying sites of interest (such as where ablation energy has been applied). A commercial product embodying the elements of the system 10 may be the CARTO TM 3 system, available from Biosense Webster, Inc., 31A Technology Drive, Irvine, CA 92618.

[0049] For example, the system 10 may be a surgical system (e.g., sold by Biosense Webster as part of a surgical system configured to obtain biometric data (e.g., anatomical and electrical measurements of a patient's organ such as the heart 12 as described herein) and perform a cardiac ablation procedure. More specifically, treatment of cardiac conditions such as arrhythmias typically requires obtaining a detailed map of the heart tissue, chambers, veins, arteries, and / or electrical pathways. For example, a prerequisite for successful performance of catheter ablation (as described herein) is that the cause of the arrhythmia is accurately located within the chambers of the heart 12. Such localization can be accomplished via an electrophysiological study during which electrical potentials are spatially resolved using a mapping catheter (e.g., catheter 14) introduced into the chambers of the heart 12. This electrophysiological study (so-called electroanatomical mapping) thus provides 3D mapping data that can be displayed on a display device 27. In many cases, the mapping function and the treatment function (e.g., ablation) are provided by a single catheter or a group of catheters such that the mapping catheter also operates as a treatment (e.g., ablation) catheter simultaneously.

[0050] Figure 2 is a block diagram of an example system 100 for remotely monitoring and transmitting patient biometrics (i.e., patient data). In Figure 2 the example shown, system 100 includes a patient biometric monitoring and processing device 102 associated with a patient 104, a local computing device 106, a remote computing system 108, a first network 110, a patient biometric sensor 112, a processor 114, a user input (UI) sensor 116, a memory 118, a second network 120, and a transmitter-receiver (i.e., transceiver) 122.

[0051] According to one embodiment, the patient biometric monitoring and processing device 102 can be a device that is inside the patient's body (e.g., subcutaneously implantable), such as Figure 1 the catheter 14. The patient biometric monitoring and processing device 102 can be inserted into the patient's body via any suitable means, including oral injection, surgical insertion via a vein or artery, endoscopic procedure, or laparoscopic procedure.

[0052] According to one embodiment, the patient biometric monitoring and processing device 102 can be a device that is outside the patient's body, such as Figure 1 the electrode patch 38. For example, as described in more detail below, the patient biometric monitoring and processing device 102 can include an attachable patch (e.g., which attaches to the patient's skin). The monitoring and processing device 102 can also include a catheter, probe, blood pressure cuff, scale, bracelet or smartwatch biometric tracker, glucose monitor, continuous positive airway pressure (CPAP) machine, or almost any device that can provide input related to the patient's health or biometrics.

[0053] According to one embodiment, the patient biometric monitoring and processing device 102 may include both components internal to the patient and components external to the patient.

[0054] Figure 2 A single patient biometric monitoring and processing device 102 is shown. However, an exemplary system may include multiple patient biometric monitoring and processing devices. The patient biometric monitoring and processing device may communicate with one or more other patient biometric monitoring and processing devices. Additionally or alternatively, the patient biometric monitoring and processing device may communicate with the network 110.

[0055] One or more patient biometric monitoring and processing devices 102 may collect patient biometric data (e.g., electrical signals, blood pressure, temperature, blood glucose level, or other biometric data), and receive at least a portion of the patient biometric data representing the collected patient biometrics and additional information associated with the collected patient biometrics from one or more other monitoring and processing devices 102. The additional information may be, for example, diagnostic information and / or additional information obtained from additional devices such as wearable devices. Each patient biometric monitoring and processing device 102 may process the data, including the patient biometrics collected by itself and the data received from one or more other patient biometric monitoring and processing devices 102.

[0056] Biometric data (e.g., patient biometrics, patient data, or patient biometric data) may include one or more of local activation time (LAT), electrical activity, topology, bipolar mapping, reference activity, ventricular activity, dominant frequency, impedance, etc. The LAT may be a time point corresponding to the threshold activity of local activation calculated based on a normalized initial starting point. The electrical activity may be any applicable electrical signal that can be measured based on one or more thresholds and sensed and / or enhanced based on signal-to-noise ratio and / or other filters. The topology may correspond to the physical structure of a body part or a portion of a body part, and may correspond to the variation of the physical structure with respect to different parts of the body part or with respect to different body parts. The dominant frequency may be a frequency or frequency range prevalent at a portion of a body part, and may be different in different parts of the same body part. For example, the dominant frequency of the PV of the heart may be different from the dominant frequency of the right atrium of the same heart. The impedance may be a resistance measurement result at a given region of a body part.

[0057] Examples of biometric data include, but are not limited to, patient identification data, intracardiac electrocardiogram (IC ECG) data, bipolar intracardiac reference signals, anatomical and electrical measurements, trajectory information, body surface (BS) ECG data, historical data, brain biometrics, blood pressure data, ultrasound signals, radio signals, audio signals, two-dimensional or three-dimensional image data, blood glucose data, and temperature data. Biometric data can generally be used to monitor, diagnose, and treat any number of various diseases, such as cardiovascular diseases (e.g., arrhythmias, cardiomyopathies, and coronary artery diseases) and autoimmune diseases (e.g., type I and type II diabetes). Note that BS ECG data can include data and signals collected from electrodes on the patient's surface, IC ECG data can include data and signals collected from electrodes within the patient's body, and ablation data can include data and signals collected from tissue that has been ablated. Additionally, BS ECG data, IC ECG data, and ablation data, along with catheter electrode positioning data, can be derived from one or more procedural recordings.

[0058] In Figure 2 the network 110 is an example of a short-range network (e.g., a local area network (LAN) or a personal area network (PAN)). Information can be sent between the patient biometric monitoring and processing device 102 and the local computing device 106 via the network 110 using any one of a variety of short-range wireless communication protocols, such as Bluetooth, Wi-Fi, Zigbee, Z-Wave, near field communication (NFC), ultraband, Zigbee, or infrared (IR).

[0059] The network 120 can be a wired network, a wireless network, or include one or more wired and wireless networks. For example, the network 120 can be a remote network (e.g., a wide area network (WAN), the Internet, or a cellular network). Information can be sent via the network 120 using any one of a variety of remote wireless communication protocols, such as TCP / IP, HTTP, 3G, 4G / LTE, or 5G / new radio.

[0060] The patient biometric monitoring and processing device 102 can include a patient biometric sensor 112, a processor 114, a UI sensor 116, a memory 118, and a transceiver 122. The patient biometric monitoring and processing device 102 can continuously or periodically monitor, store, process, and transmit any number of various patient biometrics. Examples of patient biometrics include electrical signals (e.g., ECG signals and brain biometrics), blood pressure data, blood glucose data, and temperature data. Patient biometrics can be monitored and transmitted to treat any number of various diseases, such as cardiovascular diseases (e.g., arrhythmias, cardiomyopathies, and coronary artery diseases) and autoimmune diseases (e.g., type I and type II diabetes).

[0061] The patient biometric sensor 112 may include, for example, one or more sensors configured to sense a type of biometric patient biometrics. For example, the patient biometric sensor 112 may include electrodes configured to acquire electrical signals (e.g., cardiac signals, brain signals, or other bioelectrical signals), a temperature sensor, a blood pressure sensor, a blood glucose sensor, a blood oxygen sensor, a pH sensor, an accelerometer, and a microphone.

[0062] As described in more detail below, the patient biometric monitoring and processing device 102 may be an ECG monitor for monitoring an ECG signal of the heart (e.g., heart 12). The patient biometric sensor 112 of the ECG monitor may include one or more electrodes for acquiring the ECG signal. The ECG signal may be used to treat various cardiovascular diseases.

[0063] In another example, the patient biometric monitoring and processing device 102 may be a continuous glucose monitor (CGM) for continuously monitoring a patient's blood glucose level to treat various diseases, such as type I and type II diabetes. The CGM may include a subcutaneously disposed electrode that may monitor the blood glucose level from the patient's interstitial fluid. The CGM may be, for example, a component of a closed-loop system where the blood glucose data is sent to an insulin pump for calculating insulin delivery without user intervention.

[0064] The transceiver 122 may include a separate transmitter and receiver. Alternatively, the transceiver 122 may include a transmitter and receiver integrated into a single device.

[0065] The processor 114 may be configured to store patient data, such as patient biometric data acquired by the patient biometric sensor 112, in the memory 118, and transmit the patient data across the network 110 via the transmitter of the transceiver 122. Data from one or more other patient biometric monitoring and processing devices 102 may also be received by the receiver of the transceiver 122, as described in more detail below.

[0066] According to an embodiment, the patient biometric monitoring and processing device 102 includes a UI sensor 116, which may be, for example, a piezoelectric sensor or a capacitive sensor configured to receive user input (such as a tap or a touch). For example, in response to the patient 104 tapping or contacting the surface of the patient biometric monitoring and processing device 102, the UI sensor 116 may be controlled to achieve capacitive coupling. Gesture recognition may be achieved via any of various capacitive types, such as resistive capacitive, surface capacitive, projected capacitive, surface acoustic wave, piezoelectric, and infrared touch. The capacitive sensor may be disposed at a small area or along the length of the surface such that a tap or touch on the surface activates the monitoring device.

[0067] As described in more detail below, the processor 114 can be configured to selectively respond to different tap patterns (e.g., single tap or double tap) of a capacitive sensor, which can be the UI sensor 116, such that different tasks of the patch (e.g., acquisition, storage, or transmission of data) can be activated based on the detected pattern. In some embodiments, when a gesture is detected, an audible feedback can be given to the user from the patient biometric monitoring and processing device 102.

[0068] The local computing device 106 of the system 100 communicates with the patient biometric monitoring and processing device 102 and can be configured to act as a gateway to the remote computing system 108 via the second network 120. For example, the local computing device 106 can be, for example, a smart phone, a smart watch, a tablet computer, or other portable intelligent device configured to communicate with other devices via the network 120. Alternatively, the local computing device 106 can be a fixed or stand-alone device, such as a fixed base station including, for example, modem and / or router capabilities, a desktop computer or a laptop computer using an executable program to transmit information between the patient biometric monitoring and processing device 102 and the remote computing system 108 via the radio module of the PC, or a USB dongle. Patient biometrics can be transmitted between the local computing device 106 and the patient biometric monitoring and processing device 102 via a short-range wireless network 110, such as a local area network (LAN) (e.g., a personal area network (PAN)), using short-range wireless technology standards (e.g., Bluetooth, Wi-Fi, ZigBee, Z-wave, and other short-range wireless standards). In some embodiments, the local computing device 106 can also be configured to display the acquired patient electrical signals and information associated with the acquired patient electrical signals, as described in more detail below.

[0069] In some embodiments, the remote computing system 108 can be configured to receive at least one of the monitored patient biometrics and information associated with the monitored patient via the network 120 as a remote network. For example, if the local computing device 106 is a mobile phone, the network 120 can be a wireless cellular network, and information can be transmitted between the local computing device 106 and the remote computing system 108 via wireless technology standards such as any of the wireless technologies described above. As described in more detail below, the remote computing system 108 can be configured to provide (e.g., visually display and / or audibly provide) at least one of the patient biometrics and related information to a healthcare professional (e.g., a physician).

[0070] Figure 3Is a system diagram of an example of a computing environment 200 that communicates with network 120. In some cases, computing environment 200 is incorporated into a public cloud computing platform (such as Amazon Web Services or Microsoft Azure), a hybrid cloud computing platform (such as HP Enterprise OneSphere), or a private cloud computing platform.

[0071] As Figure 3 shown, computing environment 200 includes a remote computing system 108 (hereinafter referred to as a computer system), which is an example of a computing system on which the embodiments described herein can be implemented.

[0072] Remote computing system 108 can perform various functions via a processor 220 that may include one or more processors. The functions may include analyzing monitored patient biometrics and associated information and providing (e.g., via display 266) alerts, additional information, or instructions based on thresholds and parameters determined by a physician or algorithm-driven. As described in more detail below, remote computing system 108 can be used to provide (e.g., via display 266) a patient information dashboard to healthcare personnel (e.g., physicians) such that such information can enable healthcare personnel to identify and prioritize patients with more critical needs than others.

[0073] As Figure 3 shown, computer system 210 may include a communication mechanism (such as bus 221) or other communication mechanism for transferring information within computer system 210. Computer system 210 also includes one or more processors 220 coupled to bus 221 for processing information. Processors 220 may include one or more CPUs, GPUs, or any other processors known in the art.

[0074] The computer system 210 also includes a system memory 230 coupled to the bus 221 for storing information and instructions to be executed by the processor 220. The system memory 230 may include computer-readable storage media in the form of volatile and / or non-volatile memory, such as read-only system memory (ROM) 231 and / or random access memory (RAM) 232. The system memory RAM 232 may include other dynamic storage devices (e.g., dynamic RAM, static RAM, and synchronous DRAM). The system memory ROM 231 may include other static storage devices (e.g., programmable ROM, erasable PROM, and electrically erasable PROM). In addition, the system memory 230 may be used to store temporary variables or other intermediate information during the execution of instructions by the processor 220. The basic input / output system 233 (BIOS) may contain routines for transferring information between elements within the computer system 210 (such as during the startup process), and this routine may be stored in the system memory ROM 231. The RAM 232 may contain data and / or program modules that can be immediately accessed by the processor 220 and / or are currently being operated on by this processor. The system memory 230 may additionally include, for example, an operating system 234, application programs 235, other program modules 236, and program data 237.

[0075] The illustrated computer system 210 also includes a disk controller 240 that is coupled to the bus 221 to control one or more storage devices for storing information and instructions, such as a hard disk 241 and a removable media drive 242 (e.g., a floppy disk drive, a compact disc drive, a tape drive, and / or a solid state drive). Storage devices can be added to the computer system 210 using an appropriate device interface (e.g., Small Computer System Interface (SCSI), Integrated Device Electronics (IDE), Universal Serial Bus (USB), or FireWire).

[0076] The computer system 210 may also include a display controller 265 coupled to the bus 221 to control a monitor or display 266, such as a cathode ray tube (CRT) or a liquid crystal display (LCD), to display information to a computer user. The illustrated computer system 210 includes a user input interface 260 and one or more input devices, such as a keyboard 262 and a pointing device 261, for interacting with a computer user and providing information to the processor 220. The pointing device 261 can be, for example, a mouse, a trackball, or a pointing stick, for transmitting direction information and command selections to the processor 220 and for controlling the movement of a cursor on the display 266. The display 266 may provide a touchscreen interface that can allow input to supplement or replace the communication of direction information and command selections by the pointing device 261 and / or the keyboard 262.

[0077] In response to one or more sequences of one or more instructions contained in a memory, such as system memory 230, being executed by processor 220, computer system 210 may perform part or each of the functions and methods described herein. Such instructions may be read into system memory 230 from another computer-readable medium, such as hard disk 241 or removable media drive 242. Hard disk 241 may contain one or more data repositories and data files used by the embodiments described herein. The data repository content and data files may be encrypted to enhance security. Processor 220 may also be employed in a multiprocessing arrangement to execute one or more sequences of instructions contained in system memory 230. In an alternative embodiment, hardwired circuitry may be used in place of or in combination with software instructions. Accordingly, the embodiments are not limited to any specific combination of hardware circuitry and software.

[0078] As described above, computer system 210 may include at least one computer-readable medium or memory for storing instructions programmed according to the embodiments described herein and for containing data structures, tables, records, or other data described herein. As used herein, the term computer-readable medium refers to any non-transitory tangible medium that participates in providing instructions to processor 220 for execution. Computer-readable media may take many forms, including but not limited to non-volatile media, volatile media, and transmission media. Non-limiting examples of non-volatile media include optical discs, solid state drives, magnetic disks, and magneto-optical discs, such as hard disk 241 or removable media drive 242. Non-limiting examples of volatile media include dynamic memory, such as system memory 230. Non-limiting examples of transmission media include coaxial cables, copper wire, and fiber optics, including the wires that make up bus 221. Transmission media may also take the form of acoustic or light waves, such as acoustic or light waves generated during radio wave and infrared data communications.

[0079] Computing environment 200 may also include computer system 210, which operates in a networked environment using logical connections to local computing device 106 and one or more other devices, the one or more other devices being such as a personal computer (laptop or desktop computer), a mobile device (e.g., a patient mobile device), a server, a router, a network PC, a peer device, or other common network nodes, and generally including many or all of the elements described above with respect to computer system 210. When used in a networked environment, computer system 210 may include a modem 272 for establishing communications over a network 120, such as the Internet. Modem 272 may be connected to system bus 221 via network interface 270 or via another suitable mechanism.

[0080] As Figure 2 and Figure 3As shown, network 120 can be any network or system known in the art, including the Internet, intranet, local area network (LAN), wide area network (WAN), metropolitan area network (MAN), direct connection or series of connections, cellular phone network, or any other network or medium capable of facilitating communication between computer system 210 and other computers (e.g., local computing device 106).

[0081] Cardiac arrhythmias, specifically atrial fibrillation, have been common and dangerous medical conditions, especially in the elderly population. In patients with normal sinus rhythm, the heart, which consists of the atria, ventricles, and excitatory conduction tissue, beats in a synchronized, patterned manner in response to electrical stimuli. In patients with cardiac arrhythmias, abnormal regions of cardiac tissue do not follow the synchronized beating cycle associated with normal conduction tissue as in patients with normal sinus rhythm. Instead, the abnormal regions of cardiac tissue conduct abnormally to adjacent tissue, disrupting the cardiac cycle into an asynchronous rhythm. Such abnormal conduction has previously been known to occur at various regions of the heart, such as in the sinoatrial (SA) node region, along the conduction pathways of the atrioventricular (AV) node and His bundle, or in the myocardial tissue forming the walls of the ventricular and atrial chambers.

[0082] Cardiac arrhythmias, including atrial arrhythmias, can be of the multiple wavelet reentry type, characterized by multiple asynchronous loops of electrical impulses that are scattered around the atrial chamber and typically self-propagating. Alternatively, or in addition to the multiple wavelet reentry type, cardiac arrhythmias can also have a focal source, such as when isolated tissue regions within the atrium beat autonomously in a rapid, repetitive manner. Ventricular tachycardia (V-tach or VT) is a tachycardia or rapid heart rhythm that originates from one of the ventricles. This is a potentially life-threatening cardiac arrhythmia because it can lead to ventricular fibrillation and sudden death.

[0083] One type of arrhythmia, atrial fibrillation, occurs when the normal electrical impulses generated by the sinoatrial node are overwhelmed by chaotic electrical impulses that originate in the atria and pulmonary veins and cause irregular impulses to be transmitted to the ventricles. This results in an irregular heartbeat, which can last from a few minutes to several weeks, or even years. Atrial fibrillation (AF) is generally a chronic condition that slightly increases the risk of death, usually due to stroke. The risk increases with age. Approximately 8% of people over the age of 80 have some degree of AF. AF is usually asymptomatic and generally not life-threatening on its own, but it can cause palpitations, weakness, dizziness, chest pain, and congestive heart failure. The risk of stroke increases during AF because blood can pool in the poorly contracting atria and left atrial appendage and form blood clots. The first line of treatment for AF is drug therapy that can slow the heart rate or restore a normal heart rhythm. Additionally, people with AF are usually given anticoagulants to prevent them from being at risk of stroke. Using such anticoagulants comes with its own risk of internal bleeding. For some patients, drug therapy is insufficient and their AF is considered drug refractory, i.e., not treatable with standard drug interventions. Synchronized cardioversion can also be used to restore AF to a normal heart rhythm. Alternatively, AF patients are treated by catheter ablation.

[0084] Treatment based on catheter ablation can include mapping the electrical properties of the heart tissue (especially the endocardium and cardiac volume), and selectively ablating the heart tissue by applying energy. For example, cardiac mapping that creates a map of the electrical potential along which waves propagate through the heart tissue (voltage map) or a map of the time of arrival to various tissue location points (local time activation (LAT) map) can be used to detect local cardiac tissue dysfunction. Ablation, such as those based on cardiac mapping, can stop or modify the propagation of unwanted electrical signals from one part of the heart to another.

[0085] The ablation process disrupts unwanted electrical pathways by forming non-conducting ablation lesions. A variety of energy delivery forms for forming ablation lesions have been disclosed and include using microwave, laser, and more commonly radiofrequency energy to create a conduction block along the heart tissue wall. In a two-step protocol of mapping and then ablation, the electrical activity at various points in the heart is typically sensed and measured by inserting a catheter containing one or more electrical sensors (or electrodes) into the heart and acquiring data at multiple points. This data is then used to select the endocardial target areas to be ablated.

[0086] As clinicians treat increasingly challenging conditions such as atrial fibrillation and ventricular tachycardia, cardiac ablation and other cardiac electrophysiology procedures are becoming increasingly complex. The treatment of complex arrhythmias currently relies on the use of three-dimensional (3D) mapping systems in order to reconstruct the anatomy of the ventricle of interest.

[0087] For example, cardiologists rely on software, such as the Complex Fractionated Atrial Electrogram (CFAE) module of the 3D mapping system from Biosense Webster, Inc. (Diamond Bar, Calif.), to analyze intracardiac EGM signals and determine ablation points for treating a wide range of cardiac conditions, including atypical atrial flutter and ventricular tachycardia.

[0088] 3D maps (sometimes referred to as electroanatomical maps) can provide multiple pieces of information about the electrophysiological properties of tissue, which represent the anatomical and functional substrate of these challenging arrhythmias.

[0089] Cardiomyopathies with different etiologies (hypoxia, dilated (DCM), hypertrophic cardiomyopathy (HCM), arrhythmogenic right ventricular dysplasia (ARVD), left ventricular non-compaction (LVNC), etc.) have recognizable substrates, characterized by regions of unhealthy tissue surrounded by functionally normal cardiomyocytes.

[0090] Figures 4A to 4D Examples of electroanatomical maps of cardiomyopathies with different etiologies are shown. As a first example, Figure 4A and Figure 4B show an exemplary rendering of a heart 400 with post-ischemic ventricular tachycardia (VT), characterized by an endocardial-epicardial low voltage or intermediate voltage region 402 where signal conduction is slowed. This shows that measuring any prolonged electrical potential inside or around a dense scar region can help identify potential isthmuses that maintain VT. Figure 4A The post-ischemic VT shown is characterized by an endocardial-epicardial low voltage or intermediate voltage region where signal conduction is slowed. This shows that measuring any prolonged electrical potential inside or around a dense scar region can help identify potential isthmuses that maintain VT. Figure 4A Shows the change in bipolar signal amplitude (Bi) in various sectors of the heart 400. Figure 4A Shows a Bi ranging from 0.5 mV to 1.5 mV. Figure 4B Shows the change in Shortex complex interval (SCI) in various sectors of the heart. For example, the SCI ranges from 15.0 milliseconds to 171.00 milliseconds, where the SCI range of interest is between 80 milliseconds and 170 milliseconds.

[0091] Figure 4C and Figure 4D show an exemplary rendering of a heart 410 experiencing left ventricular non-compaction cardiomyopathy. More specifically, Figure 4C shows an epicardial voltage map, and Figure 4D shows a potential duration map (PDM). In Figure 4C andFigure 4D Among them, the three black circles in 412 are marked as abnormally prolonged electric potentials, such as electric potentials higher than 200 milliseconds.

[0092] Abnormal tissue is usually characterized by low voltage EGM. However, initial clinical experience in endocardial-epicardial mapping indicates that low voltage areas do not always exist as the sole arrhythmogenic mechanism in such patients. In fact, low voltage or mid-voltage areas can exhibit EGM fragmentation and prolonged activity during sinus rhythm, which corresponds to the critical isthmus identified during sustained and organized ventricular arrhythmias, for example, only applicable to non-tolerant ventricular tachycardia. In addition, in many cases, EGM fragmentation and prolonged activity are observed in areas showing normal or near-normal voltage amplitudes (>1mV - 1.5mV). Although the latter areas can be evaluated based on voltage amplitude, they cannot be considered normal based on intracardiac signals and thus represent a true arrhythmogenic substrate. 3D mapping can localize the arrhythmogenic substrate on the endocardial and / or epicardial layers of the right / left ventricles, which can vary in distribution according to the extent of the primary disease.

[0093] The substrate associated with these cardiac conditions is related to the presence of fragmented and prolonged EGM in the endocardial and / or epicardial layers of the ventricular chambers (right and left). 3D mapping systems, such as 3, can localize the potential arrhythmogenic substrate of cardiomyopathy in terms of abnormal EGM detection.

[0094] Electrode catheters have been commonly used in medical practice for many years. They are used to stimulate and map the electrical activity in the heart and to ablate the sites of abnormal electrical activity. When in use, the electrode catheter is inserted into a major vein or artery such as the femoral artery and then guided into the cardiac chamber of interest. A typical ablation procedure involves inserting a catheter having at least one electrode at its distal end into the cardiac chamber. A reference electrode, which is typically taped to the patient's skin, or a second catheter disposed in or near the heart can be used to provide the reference electrode. RF (radiofrequency) current and / or pulsed field energy is applied to the tip electrode of the ablation catheter, and the current flows through the surrounding medium (i.e., blood and tissue) to the reference electrode. In RF ablation, the distribution of the current depends on the amount of contact of the electrode surface with tissue compared to blood, which has a higher conductivity than tissue. Due to the resistance of the tissue, heating of the tissue occurs. The tissue is heated sufficiently to cause cell destruction in the cardiac tissue, resulting in the formation of a non-conductive ablation lesion within the cardiac tissue. During this process, heating of the electrode also occurs due to conduction from the heated tissue to the electrode itself. If the electrode temperature becomes high enough, possibly above 60 °C, a thin transparent coating of dehydrated blood protein can form on the surface of the electrode. If the temperature continues to rise, this dehydrated layer can become thicker and thicker, leading to blood coagulation on the electrode surface. Since dehydrated biomaterials have a higher resistance than endocardial tissue, the impedance to the flow of electrical energy into the tissue also increases. If the impedance increases sufficiently, impedance rise occurs, and the catheter must be removed from the body and the tip electrode cleaned. Similarly, in PFA, the extent, depth, and effect of the cardiac injury produced by ablation depend on the proximity of the electrode to the tissue. The electric field generated during PFA produces irreversible electroporation in the cells of the cardiac tissue. This process disrupts the cell membrane, leading to cell death.

[0095] The treatment of cardiac disorders such as arrhythmias typically requires obtaining a detailed map of the cardiac tissue, chambers, veins, arteries, and / or electrical pathways. For example, a prerequisite for successful catheter ablation is that the cause of the arrhythmia is accurately located within the cardiac chamber. Such localization can be accomplished via an electrophysiological study during which the electrical potential is detected spatially resolved with a mapping catheter introduced into the cardiac chamber. This electrophysiological study (so-called electroanatomical mapping) thus provides 3D mapping data that can be displayed on a monitor. In many cases, the mapping function and the treatment function (e.g., ablation) are provided by a single catheter or a set of catheters, such that the mapping catheter also operates as a treatment (e.g., ablation) catheter simultaneously.

[0096] Mapping of cardiac regions such as the heart region, tissue, veins, arteries, and / or electrical pathways can lead to the identification of problem areas such as scar tissue, arrhythmia sources (e.g., electrical rotors), healthy regions, etc. The cardiac regions can be mapped such that a visual rendering of the mapped cardiac region is provided using a display, as further disclosed herein. Additionally, cardiac mapping can include mapping based on one or more modalities such as, but not limited to, local activation time (LAT), electrical activity, topology, bipolar mapping, dominant frequency, or impedance. Data corresponding to multiple modalities can be captured using a catheter inserted into a patient, and the data corresponding to multiple modalities can be provided simultaneously or non-simultaneously for rendering based on corresponding settings and / or preferences of a medical professional.

[0097] Cardiac mapping can be achieved using one or more techniques. As an example of a first technique, cardiac mapping can be achieved by sensing the electrical properties (e.g., local activation time) of cardiac tissue according to precise positions within the heart. Corresponding data can be acquired using one or more catheters that are advanced into the heart using catheters having electrical sensors and position sensors at their distal ends. Specifically, for example, position and electrical activity can initially be measured at about 10 to about 20 points on the inner surface of the heart. These data points are generally sufficient to generate a preliminary reconstruction or map of the heart surface with satisfactory quality. The preliminary map can be combined with data taken at additional points in order to produce a more comprehensive map of cardiac electrical activity. In a clinical setting, it is not uncommon to accumulate data at 100 or more sites to generate a detailed and comprehensive map of the electrical activity of a cardiac chamber. The generated detailed map can then be used as a basis for deciding on a course of treatment action such as tissue ablation, for example, to alter the propagation of cardiac electrical activity and restore normal heart rhythm.

[0098] Catheters containing position sensors can be used to determine the trajectories of points on the heart surface. These trajectories can be used to infer motion characteristics such as the contractility of tissue. When trajectory information is sampled at a sufficient number of points in the heart, a map depicting such motion characteristics can be constructed.

[0099] Typically, a catheter containing an electrical sensor at or near its distal end can be advanced to a point in the heart, the tissue can be contacted with the sensor, and data at that point can be acquired, thereby measuring the electrical activity at that point in the heart. One disadvantage of mapping a cardiac chamber using a catheter containing only a single distal end electrode is that it takes a relatively long time to acquire data point by point at the necessary number of points required for a detailed map of the overall chamber. Therefore, multi-electrode catheters have been developed to measure electrical activity at multiple points in a cardiac chamber simultaneously.

[0100] The multi-electrode catheter can be implemented in any suitable shape, such as a linear catheter with multiple electrodes, a balloon catheter including electrodes dispersed on multiple ridges for balloon angioplasty, a lasso or collar catheter with multiple electrodes, or any other suitable shape. Figure 5A An example of a linear catheter 502 including multiple electrodes 504, 505, and 506 that can be used to map a cardiac region is shown. The linear catheter 502 can be fully or partially elastic such that it can be distorted, bent, and / or otherwise shaped based on the received signal and / or based on an external force (e.g., cardiac tissue) applied on the linear catheter 502.

[0101] Figure 5B An example of a balloon catheter 512 is shown that includes multiple splines (e.g., Figure 5B 12 splines in a specific example), including splines 514, 516, 517, and multiple electrodes on each spline, including electrodes 521, 522, 523, 524, 525, and 526 as shown. The balloon catheter 512 can be designed such that when it is deployed into a patient's body, its electrodes can remain in close contact with the endocardial surface. For example, the balloon catheter can be inserted into a lumen (such as a pulmonary vein (PV)). The balloon catheter can be inserted into the PV in a contracted state such that the balloon catheter does not occupy its maximum volume when inserted into the PV. The balloon catheter can be inflated inside the PV such that the electrodes on the balloon catheter contact the entire circular segment of the PV. Such contact with the entire circular portion of the PV or any other lumen can enable effective mapping and / or ablation.

[0102] Figure 5C An example of a collar catheter 530 (also referred to as a lasso catheter) including multiple electrodes 532, 534, and 536 that can be used to map a cardiac region is shown. The collar catheter 530 can be fully or partially elastic such that it can be distorted, bent, and / or otherwise shaped based on the received signal and / or based on an external force (e.g., cardiac tissue) applied on the collar catheter 530.

[0103] According to one example, the multi-electrode catheter can be advanced into a chamber of the heart. Such as The navigation capabilities of a 3D mapping system can be used to establish the position and orientation of a catheter and its electrodes. This capability can be enabled via one or more position sensors (e.g., one or both of a magnetic-based sensor and an impedance-based sensor). Additionally or alternatively, imaging techniques such as intracardiac echocardiography (ICE) or anteroposterior (AP) and lateral fluoroscopy can be obtained to establish the position and orientation of each electrode. An electrogram can be recorded by each of the electrodes in contact with the heart surface relative to a time reference (such as the onset of the P wave in the sinus rhythm from a surface ECG). As further disclosed herein, the system can distinguish those electrodes that record electrical activity and those electrodes that do not record electrical activity due to not being in close proximity to the endocardial wall. After recording an initial electrogram, the catheter can be repositioned, and fluoroscopy and electrograms can be recorded again. Then, an electrical mapping diagram can be constructed based on iterations of the above process. Additionally, intracardiac ECG data can be collected by one or more diagnostic catheters placed within the heart.

[0104] According to one example, cardiac mapping can be generated based on the detection of an intracardiac potential field. A non-contact technique can be implemented to simultaneously acquire a large amount of cardiac electrical information. For example, a catheter having a distal end portion can be provided with a series of sensor electrodes distributed on its surface and connected to insulated electrical conductors for connection to a signal sensing and processing device. The size and shape of the end portion can be such that the electrodes are substantially spaced apart from the wall of the cardiac chamber. The intracardiac potential field can be detected during a single heartbeat. According to one example, the sensor electrodes can be distributed on a series of circumferences located in planes spaced apart from each other. These planes can be perpendicular to the long axis of the end portion of the catheter. At least two additional electrodes can be provided adjacent to each other at the ends of the long axis of the end. As a more specific example, the catheter can include four circumferences, with eight electrodes equally angularly spaced on each circumference. Thus, in this specific implementation, the catheter can include at least 34 electrodes (32 circumferential electrodes and 2 end electrodes).

[0105] According to another example, electrophysiological cardiac mapping systems and techniques based on non-contact and non-expanding multi-electrode catheters can be implemented. Electrograms can be obtained using a catheter having a plurality of electrodes (e.g., between 42 and 122 electrodes). According to this specific implementation, knowledge of the relative geometry of the probe and the endocardium can be obtained, for example, by an independent imaging modality such as transesophageal echocardiogram and / or 2D-ICE, 3D-ICE, or 4D-ICE. After independent imaging, non-contact electrodes can be used to measure the cardiac surface potential and construct a mapping diagram therefrom. The technique can include the following steps (after the independent imaging step): (a) measuring the potential using a plurality of electrodes disposed on a probe positioned in the heart; (b) determining the geometric relationship between the probe surface and the endocardial surface; (c) generating a coefficient matrix representing the geometric relationship between the probe surface and the endocardial surface; and (d) determining the endocardial potential based on the electrode potential and the coefficient matrix.

[0106] According to another example, techniques and devices for mapping the potential distribution of a cardiac chamber can be implemented. An intracardiac multi-electrode mapping catheter assembly can be inserted into a patient's heart. The mapping catheter assembly can include a multi-electrode array having an integral reference electrode, or preferably, include a companion reference catheter. The electrodes can be deployed in the form of a substantially spherical array. The electrode array can be spatially referenced to a point on the endocardial surface by the reference electrode or by a reference catheter in contact with the endocardial surface. A preferred electrode array catheter can carry a plurality of individual electrode sites (e.g., at least 24). Additionally, the exemplary technique can be implemented by knowing the position of each electrode site in the electrode array on the array and knowing the cardiac geometry. These positions are preferably determined by techniques of impedance plethysmography.

[0107] According to another example, a cardiac mapping catheter assembly can include an electrode array defining a plurality of electrode sites. The mapping catheter assembly can further include a lumen to receive a reference catheter having a distal end electrode assembly that can be used to probe the heart wall. The mapping catheter can include a braid of insulated wire (e.g., having 24 to 64 wires in the braid), and each wire can be used to form an electrode site. The catheter can be easily positioned in the heart for collecting electroactivity information from a first set of non-contact electrode sites and / or a second set of contact electrode sites.

[0108] According to another example, another catheter for mapping electrophysiological activity within the heart can be implemented. The catheter body can include a distal end adapted to deliver a stimulation pulse for cardiac pacing or an ablation electrode for ablating tissue in contact with the end. The catheter can further include at least a pair of orthogonal electrodes to generate a differential signal indicative of local cardiac electrical activity adjacent to the orthogonal electrodes.

[0109] According to another example, a process for measuring electrophysiological data in a heart chamber can be implemented. The method can partially include positioning a set of active and passive electrodes into the heart, providing a current to the active electrodes to generate an electric field in the heart chamber, and measuring the electric field at the passive electrode sites. The passive electrodes are included in an array positioned on an inflatable balloon of a balloon catheter. In a preferred embodiment, the array is said to have from 60 to 64 electrodes.

[0110] According to another example, cardiac mapping can be implemented using one or more ultrasound transducers. The ultrasound transducers can be inserted into a patient's heart and can collect multiple ultrasound slices (e.g., two-dimensional or three-dimensional slices) at various positions and orientations within the heart. The position and orientation of a given ultrasound transducer can be known, and the collected ultrasound slices can be stored such that they can be displayed at a later time. One or more ultrasound slices corresponding to the position of a probe (e.g., a treatment catheter) at a given time can be displayed, and the probe can be overlaid on the one or more ultrasound slices.

[0111] According to other examples, body patches and / or surface electrodes can be positioned on or near a patient's body. A catheter having one or more electrodes can be positioned within the patient's body (e.g., within the patient's heart), and the position of the catheter can be determined by the system based on signals transmitted and received between one or more electrodes of the catheter and the body patch and / or surface electrodes. Additionally, the catheter electrodes can sense biometric data (e.g., LAT values) from within the patient's body (e.g., within the heart). The biometric data can be associated with the determined position of the catheter such that a rendering of a body part (e.g., the heart) of the patient can be displayed, and the biometric data can be displayed overlaid on the shape of the body part as determined by the position of the catheter.

[0112] As discussed above, some systems can show or display the results of an ablation session via a point cloud of markers or tags representing the position of each electrode during ablation across multiple sessions. Figure 6A is a screenshot 600 of an example of such a point cloud generated from multiple ablation sessions according to one or more embodiments. Each tag 602 (which can be variously referred to as a point, a position, an electrode position, a marker, an ablation tag, or any other similar term) is represented by Figure 6A a red sphere or dot in the screenshot. In a particular implementation using a point cloud as shown in the example, it can be difficult for a physician to understand the effect of one or more ablation sessions. For example, there is no clear indication of the ablation field energy received by the tissue. The energy from the electric field between the electrodes is not represented. There is no indication of the energy accumulating in the tissue due to repeated ablation. And there is no indication of which tags were created during the same ablation session.

[0113] In contrast,Figure 6B FIG. 610 is a screenshot of an example of volumetric tracking 612 of multiple implicit functions generated by multiple ablation sessions according to one or more embodiments. The implicit functions may include signed distance functions or other smooth functions based on the positions of adjacent electrodes during an ablation session, resulting in multi-lobed regions or tube shapes. In many implementations, the surface of a region may represent the region that received the same or similar amount of energy during an ablation session. In some implementations, this may be determined via a signed distance function or any other similar smooth function.

[0114] For example, briefly referring to Figure 6C , which shows an example of an energy field 622 around multiple electrodes 620 during an ablation session according to one or more embodiments. The energy field 622 is shown as concentric circles and represents the energy gradient provided during ablation at a given distance or an equal or approximately equal amount of energy. The energy at any particular distance from the electrode may be based on the inverse square law; this is shown in Figure 6C where the lines are thinner the farther away from each electrode 620. It is understood that the illustration is for example purposes only and the thickness of the lines does not represent any particular energy level to scale or proportionally; it is also understood that although only a few concentric circles are shown, the ablation energy may extend farther than shown.

[0115] Figure 6D FIG. is an illustration of an example signed distance function 624 representing the energy field around multiple electrodes 620 during an ablation session in Figure 6C according to one or more embodiments. For example, the boundaries shown by function 624 represent the threshold distances from the left and middle electrodes, and the boundaries shown by function 624' represent the threshold distances from the middle and right electrodes, where the boundaries correspond to the energy levels received at that distance from the electrodes. Thus, in many implementations, the boundaries may also represent the points where similar or the same amount of energy is acquired around the electrodes. Thus, these functions may be combined into an aggregate implicit function to represent the regions that accumulate the same energy during each ablation session. Although shown as two-dimensional representations in Figure 6C and Figure 6D , in many implementations, a three-dimensional environment may be utilized and a three-dimensional surface may be identified based on the implicit function. Additionally, although all three electrodes are shown as "active" in Figure 6C and Figure 6D , in some implementations, an electrode may be inactive (e.g., disabled, not in contact with tissue, etc.) during an ablation session. In some implementations, such inactive electrodes may be skipped during the calculation of the implicit function.

[0116] The distance to the boundaries 624, 624' (e.g., a threshold distance) can be dynamically configurable, set by a manufacturer or an administrator, or otherwise varied. For example, a higher threshold will result in a thicker portion between adjacent electrodes, while a lower threshold may result in a narrower portion or even a discontinuity. Changing the threshold may be useful for showing different levels of accumulated energy in one or more ablation sessions.

[0117] As discussed above, each ablation session among multiple ablation sessions can be represented by an implicit function. Thus, in many embodiments, the volume rendering of these sessions can be distinguished from other sessions. For example, Figure 6E is a screenshot 630 of an example of volume tracking of multiple implicit functions according to one or more embodiments, where the highlighted implicit function 632 (shown with a highlighted boundary) corresponds to one ablation session among multiple ablation sessions. Figure 6B

[0118] Figure 6E In some embodiments, to render the volume represented by each implicit function, the system can subdivide a three-dimensional environmental region into a plurality of voxels. In some embodiments, each voxel can be associated with the nearest electrode position or the active electrode position during an ablation session. The system can compute the implicit function and determine for each voxel whether the voxel is on the boundary of the volume surface (or within the boundary in some embodiments). For example, in some embodiments, the system can determine whether the distance from the voxel to the nearest adjacent electrode is within a threshold. If so, the value of the voxel representing a unit of accumulated energy can be incremented, modified, or adjusted according to an aggregation function. When rendering the volume surface for a subsequent ablation session, the value associated with the voxel can be incremented or adjusted similarly. In various embodiments, the energy accumulation across sessions can be used by any arbitrary function, such as the square or root of the sum of the sessions on the voxels. For example, the aggregation function can include increasing the value representing the accumulated energy of the voxel based on the distance to the electrode (or electrodes). In some embodiments, the aggregation function can be based on the ablation time during an ablation session. Thus, a higher value of the voxel is associated with a location where energy is accumulated or more total energy is accumulated during multiple ablation sessions. As Figure 6EAs shown in the example screenshots, such voxels may be shaded or colored in different ways (e.g., darker in the illustrated embodiments, but other shadings or colors are possible in other embodiments). In some embodiments, transparency (either alone or in addition to texture and / or color) may be used to represent the accumulated energy, such that voxels with higher received energy may be less transparent than voxels with less received energy. These various embodiments provide an intuitive and effective visualization of the accumulated energy across multiple ablation sessions. Combinations of the functions and / or other functions discussed above may be used in various embodiments and may provide smooth variations in the color and / or texture of the surface. Thus, as used herein, shading may be used to refer to any distinct visual effect, including stripes, stippling, hatching, cross-hatching, transparency, specularity, reflectivity, color, or any other type of visual modification that may provide an indication of energy accumulation.

[0119] Turning now to Figure 7 , a method 700 for visualizing pulsed field ablation tags according to one or more exemplary embodiments is shown (e.g., performed by one or more processors of a computing device). Method 700 addresses the need for a physician to understand the effects of one or more ablation sessions in an easy and intuitive visual manner and provides high-quality, efficient visualization, reducing the processing resources required as compared to high-density arrays or bitmaps. The method begins at block 702, where, during an ablation session, one or more processors of the device may receive the position of one or more electrodes of a catheter from one or more sensors. The position may be represented in any suitable format, such as by x, y, and z coordinates, spherical coordinates, an index to a voxel in an array, or any other such format. The catheter may be of any type and form, such as the linear catheter, balloon catheter, or collar catheter discussed above, and may include one electrode or more than one electrode. In various embodiments, the sensors may include RF sensors, magnetic sensors, inductive sensors, or any other type and form of sensors or combination of sensors. Receiving the position of the electrodes may include filtering noise or other movement (e.g., due to patient inhalation), identifying periods when the electrode or catheter tip is not moving or has zero velocity, etc.

[0120] At block 703, in some embodiments, one or more processors may subdivide electrodes and / or regions into multiple clusters, and at block 704, a cluster may be selected for processing. Doing so may reduce the processing requirements for each cluster, e.g., because more distant electrodes may have minimal impact. In some embodiments, each cluster may include a subset of multiple electrodes. In some embodiments, each cluster may include a subset of voxels of a three-dimensional environment. In many embodiments, clusters may be processed in parallel because they are independent; thus, in some embodiments, block 704 may be performed in parallel for different clusters by different processors, servers, devices, or other computing means. In other embodiments, blocks 703-704 may be skipped.

[0121] At block 705, in some embodiments, an ablation session may be selected from multiple sessions, and at block 706, in some embodiments, one or more processors may select a pair of electrodes from multiple electrodes, or select a pair of receiving locations (such as an adjacent pair of locations). In some embodiments, electrodes (or locations) may be selected in response to the associated locations of the electrodes (or locations) being in the same cluster. In other embodiments, electrodes (or locations) may be selected in response to the associated locations of electrodes (or locations) received from the same ablation session. In some embodiments, each electrode may be associated with a semi-unique identifier or a unique identifier. Points or voxels in a region may be associated with the identifier of an electrode that provided energy to the point or voxel at an amplitude or energy level above a threshold during an ablation session.

[0122] At block 708, in some embodiments, one or more processors may calculate an implicit function based on the positions of the selected pair of electrodes. In some embodiments, the implicit function may include a smoothing function. In some embodiments, the implicit function may include a signed distance function. In some embodiments, the function may further be based on a predetermined threshold.

[0123] In some specific implementations, if there are additional electrodes, boxes 706 to 708 may be iteratively repeated. For example, in some specific implementations, the system may calculate a function of the first electrode or position and the second electrode or position, and then may select a third electrode position and calculate a function of the combination of the first electrode or position and the second electrode or position (e.g., the previously calculated function) and the newly selected electrode or position, thus iteratively constructing an aggregate function of all three electrodes or positions. In other specific implementations, boxes 706 to 708 may be continuously repeated using pairs of electrodes or positions (e.g., calculate a distance function of the first electrode or position and the second electrode or position, and then calculate a distance function of the second electrode or position and the third electrode or position, etc.). In such specific implementations, the system may avoid calculating twice the energy contributed by the second electrode to any particular voxel. For example, as discussed above, in some specific implementations, the value associated with each voxel in the cluster may be incremented in response to the position of the voxel being within or on the boundary of the signed distance function of the first electrode or position and the second electrode or position. In some such specific implementations, any voxel whose value has been incremented may not have its value incremented again when determining the effect of the second electrode or position and the newly selected third electrode or position. In other words, in such specific implementations, during the calculation of the effect of any ablation session, the value associated with a voxel may be incremented only once, regardless of the effect of how many adjacent electrodes are applied. In other specific implementations, such as when constructing the aggregate function discussed above, the value associated with a voxel may be incremented multiple times.

[0124] In many specific implementations, boxes 705 to 708 may be repeated for additional ablation sessions. Although shown as being repeated before box 710, in some specific implementations, boxes 705 to 710 may be repeated (e.g., the loop may occur after the first instance of box 710, and box 710 may be repeated for each additional session). Similarly, in many specific implementations, boxes 704 to 708 may be repeated for additional clusters of electrode positions within the environment. In many specific implementations, boxes 704 to 708 may be executed in parallel for different clusters by separate processors, services, or devices.

[0125] At block 710, a volumetric representation of the computed implicit function (or functions for multiple ablation sessions) may be rendered. As discussed above, in many embodiments, the system may determine a value associated with each voxel in a cluster or three-dimensional environment, the value incrementing in response to the voxel being within (or on the boundary in various embodiments) the signed distance function of a pair of adjacent electrodes or corresponding locations. In some embodiments, a unique or semi-unique identifier of one or more electrodes associated with a corresponding boundary may be stored with or associated with the voxel; in various embodiments, this may be in addition to or in place of an energy value or other counter. For example, in response to determining that a voxel is within (or on) a boundary according to a signed distance function or other smoothing function, the identifier of the associated electrode may be stored in association with the voxel such that during an ablation session the voxel includes the identifiers of a set of electrodes and their locations associated therewith. This enables the system to compute the distance to the boundary at runtime with high visual fidelity without the need to store additional data about the boundary surface. In some embodiments, the system may shade, color, make visible, or otherwise highlight or show each voxel with an incremental value to display the volumetric representation. In other embodiments, the boundary of the implicit function may be used as a reflective surface to render the representation via ray tracing. Other embodiments of rendering may be utilized as needed. The volumetric representation may be rendered to a display such as a monitor, a stereoscopic display (e.g., a virtual reality or augmented reality display or glasses), a volumetric display, a holographic display, a pseudo-three-dimensional display (e.g., a two-dimensional display with head tracking and rendering of a pseudo-three-dimensional environment), or any other suitable display.

[0126] As discussed above, at block 710, the system may utilize electrode positions and the computed function to generate a volumetric representation of one or more ablation sessions. Such an implementation is important because otherwise it may be difficult to distinguish the labels in the scatter point clouds generated during each session. In particular, it may be difficult or impossible to evaluate the number of ablations performed at a particular location, which may be a particularly important factor in determining ablation quality. The point cloud may also provide a poor representation of the ablation field energy received by the tissue (the energy between two electrodes is not well represented). Additionally, the point cloud may not provide an indication of the cumulative energy on tissue affected by more than one ablation session.

[0127] For example, Figure 8A is a screenshot 800 of an example of point clouds 802A, 802B generated by multiple ablation sessions according to one or more embodiments. As shown, point clouds 802A, 802B consist of a large number of ablation labels corresponding to electrode positions during multiple ablation sessions. In contrast, Figure 8B is a screenshot 804 of an example of volumetric representations 806A, 806B generated from point clouds 802A, 802B according to some embodiments. Compared toFigure 8A Unlike point clouds, volumetric representations allow users to distinguish between separate ablation sessions and identify the positional relationships between labels in three-dimensional space.

[0128] Figures 8C to 8E A specific implementation of how these volumetric representations can be generated is shown. Starting from Figure 8C a representation of multiple ablation labels 810 in three-dimensional space according to one or more embodiments is shown. For clarity, the ablation labels 810 are shown as stars, but can be represented by points, voxels, polygons, or any other shape. In some specific implementations, the centroid 814 of the label 810 (sometimes referred to as the volume site center, label center, label centroid, ablation session center, or similar terms) can be identified, and paths 812 can be traced through each label 810 to create multiple wedge segments 811, as Figure 8D shown. The paths 812 (and wedges 811) can then be extended orthogonally to the paths 812 using multiple voxels to represent ablation energy, time, the number of discrete ablation sessions that provided energy to a particular voxel (e.g., as an incremented sum of the sessions that provided energy to each voxel), or other characteristics. For example, the paths 812 can be represented by lines of small voxels. Adjacent voxels can be added to the paths, thereby orthogonally (e.g., laterally, medially, etc.) extending the lines with multiple voxels added depending on ablation energy, ablation time, or user or physician settings. For example, in one such specific implementation, the path can be laterally extended by five voxels in each direction based on an ablation of duration x and by ten voxels in each direction based on an ablation of duration 2x. The extension does not have to be linear and can be based on any suitable formula (e.g., geometric, exponential, etc.). As a non-limiting example, as Figure 8E shown in the exemplary specific implementation of, the marching cubes algorithm (e.g., as discussed in U.S. Patent No. 4,710,876, which is incorporated herein by reference) or a similar algorithm (e.g., marching tetrahedra algorithm or any other implicit surface rendering algorithm, etc.) can be applied to determine the smooth surface 816. For example, each voxel can be replaced with one or more polygons from a predetermined set of polygons that represent the portion of the isosurface (i.e., smooth surface 816) that passes through that voxel.

[0129] However, in Figure 8E the exemplary volumetric representation 816 appears as a closed or complete loop. This can be misleading, depending on the perspective. By utilizing a three-dimensional representation and allowing the representation 816 and / or the camera or viewing point to be redirected, a physician or other user can examine the volumetric representation from multiple angles to identify gaps. For example, according to some embodiments, Figure 8F is shown from alternating rotational angles Figure 8EExemplary volume representation 816. Hidden gaps between the ends of the ablation path can be seen more easily. Additionally, as described above, when extending the path into voxels, parameters such as time and energy can be used to determine the height and width of the resulting volume. These parameters can be configured by the manufacturer or administrator of the system, or can be dynamically modified by the user or physician. For example, as shown in the illustration of Figure 8G , a narrower width can be utilized to more easily visualize the gaps between ablation regions. This can be particularly beneficial for multiple overlapping ablation sessions, where thinner "bands" can allow for identification of small gaps. In some embodiments, the width and height can be adjusted independently, while in other embodiments, the volume can be cylindrical or spherical, and the radius of the volume can be adjusted, thereby modifying both the width and height accordingly.

[0130] Figure 9 is a flowchart of an example method for rendering volume tracking generated by multiple ablation sessions, according to one or more embodiments, as discussed above in connection with block 710.

[0131] At block 902, in some embodiments, the system can determine one or more ablation session centers or volume site centers. As discussed above, in some embodiments, the volume site center can include the centroid of the positions of ablation tags during a single session. In some embodiments, and as discussed above in connection with Figure 8C and Figure 8D , the ablation tags 810 can naturally follow a two-dimensional path 812 within a three-dimensional environment. In some such embodiments, the volume site center or centroid 814 can be determined as the two-dimensional centroid 814 from the positions of the ablation tags 810, and having a common plane of the ablation tags 810. In other embodiments, the path 813 can follow a three-dimensional helical or spiral path. In many embodiments, each tag can have a position in three-dimensional space, and thus, the centroid can be calculated as the average of the coordinates of each point (e.g., c = average(x1:x n ), average(y1:y n ), average(z1:z n )). In other embodiments, the median or midpoint of the extreme values can be used to find the centroid. These may result in different centroids, and thus, the specific formula used can depend on the particular embodiment or type of catheter.

[0132] At block 904, in some embodiments, volume 816 may be generated based on volumetric dispersion. In some embodiments, this may include generating a central path 812 along ablation tags 810 that surround centroid 814. Central path 812 may be represented by a string or set of connected voxels. For example, in some embodiments, given a centroid, a first tag, and a second tag, an arc between the first tag and the second tag may be determined along path 812. As discussed above, in many embodiments, centroid 814 and each tag 810 may be associated with three-dimensional coordinates within the environment, and these three-dimensional coordinates may be used to calculate the arc. For example, in one such embodiment, a radius r may be calculated based on the distance from centroid 814 to each of two adjacent ablation tags 810 (e.g., as an average of the Euclidean distances between each tag and the centroid in three dimensions). Then, given the determined radius, centroid, and tags as the start and end points along the circumference of a circle of radius r centered at the centroid, an arc segment may be calculated (e.g., given a plane containing the start point, end point, and centroid point, the system may identify the unit vector from the centroid to the start point in the plane as x', the orthogonal unit vector in the plane as y', and calculate a portion of the circle f(t) = r cos(t) x' + r sin(t) y', where t is equal to the angle between the vectors from the centroid to each tag). In other embodiments, a Bezier curve or spline curve may be calculated (e.g., using tangents orthogonal to the vectors from the centroid to the corresponding tag at each of the start and end ablation tags, etc.). Voxels along the determined path 812 may be included in the path.

[0133] For volumetric dispersion, in some embodiments, the system may calculate the distance from each voxel within the environment to each tag 810 and the calculated path 812 (or the voxels of path 812 as discussed above). If the distance is below a threshold, then in some embodiments, the voxel may be included in the volume. In other embodiments, the calculated path 812 may be extended as discussed above (e.g., by including a given number of adjacent voxels in the volume based on the configured height or width of the volume).

[0134] At block 906, in some embodiments, a volumetric representation 816 of path 812 may be presented. Rendering volumetric representation 816 may include according to as described above in connection with Figure 8DThe ablation characteristics being discussed (such as cumulative deposited energy, total ablation time, number of discrete ablation sessions delivering energy to a particular voxel (e.g., as a sum of sessions delivering energy to each voxel), etc.) and / or parameters set by a user or physician (such as visualization radius, height, width, or filter thresholds for any of the above parameters) are used to expand the voxels of the central path 812. As discussed above, in some embodiments, the path 812 may be represented by a line of small voxels. Adjacent voxels may be added to the path, thus orthogonally (e.g., laterally, medially, etc.) expanding the line with multiple voxels added depending on ablation energy, ablation time, or settings of the user or physician. For example, a physician or user may set a minimum energy threshold, and voxels associated with deposited energy below that threshold may not be included in the rendering. As discussed above, once the voxels have been identified, the surface of the volume may be determined, for example, via a marching cubes algorithm, a ball pivoting algorithm (BPA), or a fast anatomical mapping (FAM) algorithm. For example, the system may generate a polygonal mesh of the surface by identifying three points or voxels intercepted by a three-dimensional sphere or ball of a given diameter, generating a surface triangle from those three points, and then repeating the process starting from the edges of this triangle. Once the surface boundary has been determined, a distance field may be generated and volume rays may be traced.

[0135] As discussed above, various parameters including filtering parameters or visualization parameters may be adjusted at block 908 and the execution of blocks 904 to 906 may be repeated. Additionally, blocks 902 to 906 may be repeated at block 910 for additional ablation sessions or clusters of ablation tags in the environment. The results may be displayed to the user. In many embodiments, the user or physician may then perform further modification or editing of the visualization parameters and re-render the results, including rotation, repositioning of the virtual camera or viewpoint, scaling, filtering, or other such functions.

[0136] Thus, embodiments of the systems and methods discussed herein provide an intuitive and easily understandable visualization of the effects of one or more ablation sessions on tissue, via the use of implicit functions, particularly signed distance functions, calculated based on the positions of adjacent electrodes of a catheter during ablation, and these embodiments reduce processing or resource consumption relative to array-based embodiments.

[0137] While the features and elements have been described specifically above, those of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with other features and elements. In addition, the methods described herein can be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted via wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as internal hard disks and removable disks), magneto-optical media, and optical media (such as CD-ROM disks and digital versatile disks (DVDs)). A processor associated with software can be used to implement a radio frequency transceiver used in a WTRU, UE, terminal, base station, RNC, or any host computer.

[0138] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram may represent a module, segment, or portion of instructions, which includes one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It should also be noted that each block of the block diagrams and / or flowchart illustrations, and combinations of blocks in the block diagrams and / or flowchart illustrations, can be implemented by a system based on dedicated hardware for performing the specified functions or acts, or by a combination of dedicated hardware and computer instructions.

[0139] While the features and elements have been described specifically above, those of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with other features and elements. In addition, the methods described herein can be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. As used herein, a computer-readable medium should not be construed to be a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., an optical pulse passing through an optical fiber cable), or an electrical signal transmitted through a wire.

[0140] Examples of computer-readable media include electronic signals (transmitted via wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, registers, cache memories, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, optical media such as compact discs (CDs) and digital versatile discs (DVDs), random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), and memory sticks. A processor associated with software can be used to implement a radio frequency transceiver used in a terminal, a base station, or any host computer.

[0141] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" include plural referents. It should also be understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0142] The description of the various embodiments herein is presented for purposes of illustration, but is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terms used herein were chosen to best explain the principles of the embodiments, the practical application, or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A system for visualizing a pulsed field ablation label, the system comprising: a device including a processor and a catheter, the processor being in communication with one or more sensors, the catheter including a plurality of electrodes; and wherein the processor is configured to: during a plurality of ablation sessions, receive, via the one or more sensors, the position of each of the plurality of electrodes within a three-dimensional environment, for each ablation session, calculate a first implicit function representing the energy field corresponding to the ablation session based on the received positions of each of the plurality of electrodes, and identify the intersection of the calculated energy fields of the plurality of ablation sessions corresponding to regions having a number of ablation applications exceeding a threshold; and present a first volumetric representation of the identified intersection of the calculated energy fields via a display.

2. The system according to claim 1, wherein, The processor is further configured to calculate the first implicit function via a signed distance function based on the positions of a pair of adjacent electrodes among the plurality of electrodes during the corresponding ablation session.

3. The system according to claim 2, wherein The processor is further configured to calculate the implicit function via a plurality of signed distance functions, each signed distance function corresponding to a different pair of adjacent electrodes.

4. The system according to claim 1, wherein Each of the plurality of electrodes is associated with a unique identifier; and wherein the processor is further configured to, for each of a plurality of voxels of the three-dimensional environment, determine one or more identifiers of the electrodes that supply energy to the position corresponding to the voxel during each ablation session.

5. The system according to claim 1, wherein, The processor is further configured to, for each of the plurality of voxels of the three-dimensional environment, calculate the distance from the voxel to the positions of the electrodes among the plurality of electrodes.

6. The system according to claim 5, wherein, The processor is further configured to, for each of the plurality of voxels of the three-dimensional environment, determine whether the corresponding calculated distance is less than a threshold.

7. The system according to claim 6, wherein, The processor is further configured to, for one or more of the plurality of voxels of the three-dimensional environment, modify a value associated with the voxel in response to the corresponding calculated distance being less than the threshold.

8. The system according to claim 6, wherein The processor is further configured to modify a value associated with the first voxel in response to the distance from the first voxel to the positions of the electrodes among the plurality of electrodes being less than the threshold during the corresponding ablation session; and modify the value associated with the first voxel in response to the distance from the first voxel to the positions of the electrodes among the plurality of electrodes being less than the threshold during a different ablation session.

9. The system according to claim 6, wherein, The processor is further configured to present the first volumetric representation as one or more voxels in the three-dimensional environment, each voxel being shaded based on the value associated with the voxel.

10. The system according to claim 1, wherein The processor is further configured to: determine the centroid of the received positions for each ablation session; and construct a center path around the determined centroid for each ablation session.

11. The system according to claim 1, wherein, The processor is further configured to: classify the positions of each of the plurality of electrodes into a plurality of clusters during each ablation session; and and for each ablation session, calculate the first implicit function via a signed distance function between paired electrodes within each cluster.

12. A method for visualizing a pulsed field ablation label, the method comprising: During a plurality of ablation sessions, receiving, by a processor of a device, the position of each of a plurality of electrodes of a catheter within a three-dimensional environment from one or more sensors; For each ablation session, calculating, by the processor, a first implicit function representing the energy field corresponding to the respective ablation session based on the positions of each of the plurality of electrodes received; Identifying the intersection of the calculated energy fields of the plurality of ablation sessions corresponding to regions having a number of ablation applications exceeding a threshold; And Presenting, by the processor via a display, a first volumetric representation of the identified intersection of the calculated energy fields.

13. The method according to claim 12, the method further comprising calculating the first implicit function via a signed distance function based on the positions of a pair of adjacent electrodes of the plurality of electrodes during the respective ablation session.

14. The method according to claim 13, the method further comprising calculating the implicit function via a plurality of signed distance functions, each signed distance function corresponding to a different pair of adjacent electrodes.

15. The method according to claim 12, wherein, Each of the plurality of electrodes is associated with a unique identifier; and the method further comprises, for each of a plurality of voxels of the three-dimensional environment, determining one or more identifiers of electrodes that supply energy to a position corresponding to the voxel during the respective ablation session.

16. The method according to claim 12, the method further comprising, for each of a plurality of voxels of the three-dimensional environment, calculating the distance from the voxel to the position of an electrode of the plurality of electrodes.

17. The method according to claim 16, the method further comprising, for each of the plurality of voxels of the three-dimensional environment, determining whether the respective calculated distance is less than a threshold.

18. The method according to claim 17, the method further comprising, for one or more of the plurality of voxels of the three-dimensional environment, modifying a value associated with the voxel in response to the respective calculated distance being less than the threshold.

19. The method according to claim 17, the method further comprising modifying a value associated with the first voxel in response to the distance from the first voxel to the position of an electrode of the plurality of electrodes being less than the threshold during a respective ablation session; and modifying the value associated with the first voxel in response to the distance from the first voxel to the position of an electrode of the plurality of electrodes being less than the threshold during a different ablation session.

20. The method according to claim 17, the method further comprising presenting, by the processor, the first volumetric representation as one or more voxels in the three-dimensional environment, each voxel being shaded based on the value associated with the voxel.

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