Method and system for calculating and utilizing PFA ablation index

Abstract

The invention discloses a method and system for calculating and utilizing PFA ablation index. A method, apparatus, and computer program product, the method comprising receiving an input from a force sensor on a catheter, the catheter comprising electrodes for ablating a heart of a patient, the catheter being placed at a location within the heart; calculating a predicted PFA ablation index (PFA AI) of the ablation based at least on the received input, the predicted PFA ablation index (PFA AI) to be caused by applying, by the catheter, a predetermined number of electrical pulses at the location equal to the evaluated force to achieve a predetermined amplitude and a predetermined duration, wherein the calculation conforms to a predefined formula; and displaying the predicted PFA AI to a user of the catheter.

Description

Technical Field

[0001] The present disclosure relates generally to medical devices, and in particular to systems and methods for displaying information related to irreversible electroporation of physiological tissue. Background Art

[0002] Arrhythmias can be caused by problems with the electrical activity in the heart's electrical conduction system and, in particular, in one or more points or zones on the walls of the heart chambers. Atrial fibrillation is a type of arrhythmia characterized by chaotic signals that cause the atria (left and / or right) to squeeze very quickly and in an asynchronous rhythm.

[0003] A common treatment for atrial fibrillation (also known as A-fib) is ablation, which uses energy to create scars over one or more active areas on the heart wall in order to block the erroneous electrical signals that contribute to the disorder and restore a normal heartbeat.

[0004] Irreversible electroporation (IRE), also known as pulsed field ablation (PFA), is a soft tissue ablation technique that generates an electric field by applying short pulses of high-amplitude DC signals through a probe in contact with or in close proximity to the tissue, which can cause lethal nanopores in the cell membrane, thereby disrupting cellular homeostasis (internal physical and chemical conditions). Cell death after IRE is due to apoptosis (programmed cell death) rather than necrosis (cell damage that leads to the destruction of the cell through the action of its own enzymes), as in all other ablation techniques based on heat or radiation. IRE is often used to ablate tumors in areas where precision and preservation of the extracellular matrix, blood flow, and nerves are important.

[0005] An example pulsed field generator and controller for controlling PFA pulses or PFA application are shown and described in U.S. patent application US20210186604A1, which is incorporated herein by reference in its entirety. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The present disclosure will be more fully understood through the following detailed description of examples of the present disclosure in conjunction with the accompanying drawings, in which:

[0007] Figure 1A is a schematic illustration of a catheter-based electrophysiological (EP) mapping and ablation system according to some exemplary embodiments of the present disclosure;

[0008] Figure 1B is a schematic illustration of a catheter according to some exemplary embodiments of the present disclosure;

[0009] Figure 2is a flow chart of steps in a method for calculating, displaying, and utilizing a predicted PFA index according to some exemplary embodiments of the present disclosure; and

[0010] Figure 3 is a schematic block diagram of a computing platform for calculating, displaying, and utilizing a predicted PFA index according to some exemplary embodiments of the present disclosure. DETAILED DESCRIPTION

[0011] In the following description, numerous specific details are set forth in order to provide a comprehensive understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. In other cases, well-known circuits, control logic components, and details of computer program instructions for conventional algorithms and processes are not shown in detail to avoid unnecessarily obscuring the present invention.

[0012] Software programming code embodying aspects of the present invention is typically stored in a permanent storage device such as a computer-readable medium. In a client-server environment, such software programming code may be stored on a client or a server. The software programming code may be contained in any of a variety of known media used with a data processing system. This includes, but is not limited to, magnetic and optical storage devices such as disk drives, tapes, compact disks (CDs), digital video disks (DVDs), and computer instruction signals contained in a transmission medium with or without a carrier wave modulating the signal. For example, the transmission medium may include a communication network such as the Internet. In addition, although the present invention may be embodied in computer software, the functionality required to implement the present invention may alternatively be embodied in part or in whole using hardware components, such as application specific integrated circuits or other hardware, or some combination of hardware components and software.

[0013] Overview

[0014] Pulsed field ablation (PFA) is a method of generating an electric field at a region of interest to induce irreversible electroporation (IRE) to ablate tissue cells by inducing apoptosis (programmed cell death). The IRE electric field is generally delivered by a signal generator in the form of one or more high voltage pulse trains.

[0015] PFA can be delivered using bipolar or monopolar delivery. For bipolar delivery, a direct current is delivered between a pair of electrodes near the tissue (e.g., generally in contact with the tissue) to generate a local electric field near the tissue to be ablated, thereby killing tissue cells between the electrodes. For monopolar application, current is delivered between an electrode near the tissue (e.g., generally in contact with the tissue) and a larger return electrode, which can be a patch on the patient's skin or can be a reference electrode on the catheter itself, which is immersed in a pool of blood or contacts the tissue at a location away from the location configured for ablation.

[0016] The effectiveness of applying PFA, i.e., the quality of ablation, can be estimated and / or evaluated based on calculating a PFA ablation index (AI). The PFA ablation index provides an indication of the parameters of the lesion produced by PFA, such as the lesion area and / or depth. The lesion, and therefore the PFA ablation index, may depend on the parameters of the applied pulses, including the contact force applied by the catheter on the heart wall (the inventors have found that the contact force is an important parameter affecting the quality of the lesion caused), as well as the number of pulses, the frequency, the duration, and the amplitude of the pulses. In particular, unlike the number, frequency, the duration, and the amplitude of the applied pulses, which are fixed, the applied force may be controlled by the physician, thereby enabling the physician to control the quality of the lesion caused by PFA, and thus the PFA ablation index.

[0017] Optionally, the PFA ablation index may depend more specifically on the contact force applied by one or more selected electrodes of the catheter. Optionally, the selected electrodes are electrodes determined to contact the heart wall. The PFA ablation index may further depend on the particular location within the heart wall where ablation is applied, and may be affected by, for example, the tissue type, its thickness and its morphology.

[0018] Typically, ablation is performed by repeatedly applying a train of pulses with a pause between applications, e.g., about 1 second. By calculating an incremental AI and adding the incremental AI to the cumulative AI of all delivered applications, the AI ​​can be calculated and displayed after each application so that the user can decide whether and how to apply another train of pulses.

[0019] Typically, the pulse parameters are predetermined. Therefore, the parameters that are typically controllable by the physician performing the ablation are the position and force applied by the electrode to the heart wall. However, the physician may not have a good feel for how much contact force needs to be applied to obtain a satisfactory PFA AI. Therefore, by displaying the predicted PFA AI based on the current applied force, the physician can fine-tune the applied force to achieve the desired effect. In addition, the physician may desire to obtain a desired PFA AI and maintain that PFA AI across a lesion formed by multiple ablation sites. Therefore, in some example embodiments, the calculated and displayed predicted PFA AI can help the physician achieve the desired PFA AI and / or achieve a uniform PFAAI across an ablation area formed by multiple ablation sites.

[0020] Thus, according to some embodiments of the present disclosure, contact force is monitored and a predicted PFA ablation index can be calculated based on the assumption that the physician will maintain the contact force for a predefined number of applications. The predicted PFA AI can be displayed to the physician and can provide the physician with instructions on how much contact force to apply to achieve a desired PFA AI, such as a desired lesion size and / or depth. The displayed predicted PFA can be automatically and continuously updated as the contact force applied by the physician changes.

[0021] In some embodiments, the combined force exerted by the catheter on the heart wall can be measured, wherein the force exerted by one or more electrodes contacting the heart wall can contribute to the force. In other embodiments, the individual forces exerted by one or more electrodes can be considered.

[0022] This index can be predicted using the same equation used to calculate the actual PFA AI.

[0023] The index can be calculated by integrating the effect of each pulse over a predetermined number of pulses, assuming that during all pulses the force remains at the same value as the currently measured value.

[0024] Based on this prediction, the physician can then decide whether to ablate at a particular location, and whether to ablate with the current forces applied to the tissue, or to change the location and / or applied forces.

[0025] The predicted PFA ablation index may be displayed to the user continuously or only when the catheter and / or electrodes contact tissue, and the display may change as the physician changes the position of the catheter and / or electrodes or the forces they apply to the heart wall.

[0026] System Description

[0027] refer to Figure 1A, which shows an exemplary catheter-based electrophysiology mapping and ablation system 10. The system 10 may include multiple catheters that are inserted into chambers or vascular structures of the heart 12 by a physician 24 through the vascular system of a patient 23 through the skin. Typically, a delivery sheath catheter is inserted into the left atrium or right atrium near a desired location in the heart 12. One or more catheters may then be inserted into the delivery sheath catheter to reach the desired location in the heart 12. Multiple catheters, including, for example, catheter 14, may include a catheter dedicated to sensing intracardiac electrogram (IEGM) signals, a catheter dedicated to ablation, and / or a catheter for both sensing and ablation. The physician 24 may place the distal tip 28 of the catheter 14 in contact with the heart wall for obtaining a prediction of a PFA ablation index, or for ablating a target site in the heart 12.

[0028] Catheter 14 is an exemplary catheter for use with an irreversible electroporation (IRE) ablation system. Catheter 14 may include a distal tip 28. Distal tip 28 may include a plurality of electrodes 55 connected by wires extending through catheter 14 to console 30.

[0029] Once distal end 28 of catheter 14 is inserted into the patient and reaches the target location within heart 12, physician 24 may manipulate catheter 14 to place electrodes 55 disposed on distal tip 28 in contact with the target location, such as the ostium of a pulmonary vein.

[0030] In the examples described herein, electrode 55 may be used to perform IRE ablation of left atrial tissue of heart 12 (eg, pulmonary vein ostium tissue in heart 12 ) via high voltage.

[0031] The proximal end of the catheter 14 receives energy from an IRE ablation energy generator 50 via a console 30. The IRE power source 50 may generate, but is not limited to, pulsed field ablation (PFA) energy, including high voltage DC pulses of monopolar, bipolar, or a combination thereof, such as may be used to achieve irreversible electroporation (IRE). The bipolar pulses may be applied between one or more pairs of electrodes 55. The electrode pairs 55 through which the pulses are applied may be selected according to an applicable protocol for achieving uniformity and penetration depth of the IRE field into the tissue with minimal heating side effects.

[0032] Now also refer to Figure 1B , an enlarged schematic view of the distal tip 28 of the catheter 14 is shown.

[0033] Distal tip 28 includes a plurality of electrodes 50 positioned on splines 55. Figure 1B In the exemplary embodiment of , the distal tip 28 includes three splines arranged in a sphere, wherein each spline has four electrodes disposed thereon.

[0034] The end of each spline is coupled to the central shaft 60. The central shaft 60 may include an irrigation system and one or more irrigation openings 104 for injecting irrigation fluid into the heart.

[0035] The central shaft 60 may also include a force sensor 62 configured to sense the total force exerted on the heart wall electrodes 55. The force may be calculated as the sum (or average or any other integral) of the forces exerted on the heart wall by each of the electrodes 55; the sum (or average or any other integral) of the forces exerted by those electrodes 55 that will receive energy and cause ablation according to the protocol; the maximum force exerted on the heart wall by any one of the electrodes 55, etc.

[0036] Central shaft 60 may also include a position sensor 64 for tracking the position and orientation of distal tip 28. Optionally and preferably, the position sensor is a magnetic-based position sensor that includes three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0037] The magnetic-based position sensor can operate with a positioning pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field in a predefined working space. The real-time position of the distal tip 28 of the catheter 14 or any electrode 55 can be tracked based on the magnetic field generated by the positioning pad 25 and sensed by the magnetic-based position sensor 64. Details of magnetic-based position sensing technology are described in U.S. Patents 5,5391,199, 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.

[0038] The system 10 may include one or more electrode patches 38 positioned in contact with the skin of the patient 23 to establish a position reference for impedance-based tracking of the positioning pad 25 and the electrodes 55. For impedance-based tracking, current is directed toward the electrodes 55 and sensed at the electrode skin patches 38 so that the position of each electrode can be triangulated via the electrode patches 38. Details of impedance-based position tracking techniques are described in U.S. Patents 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182.

[0039] Once ablation energy has been applied to the tissue, the force applied by the distal tip 28 on the heart wall and optionally the position within the heart can be used to calculate a PFA ablation index. However, assuming that the physician 24 will apply the same amount of force, the force and optionally the position can also be used to predict the PFA ablation index before applying the energy, so that the physician 24 can apply the required force at a specific location to achieve the desired damage and / or the desired PFA AI. The predicted PFA ablation index can be calculated based on the force in the same manner as the actual PFA ablation index is calculated once the energy is applied.

[0040] The recorder 11 may record and display electrograms 21 captured with the surface ECG electrodes 18 and intracardiac electrograms (IEGMs) captured with corresponding catheters. The recorder 11 may include pacing capabilities for pacing the cardiac rhythm and / or may be electrically connected to a separate pacemaker.

[0041] The patient interface unit (PIU) 30 is an interface configured to establish electrical communications between catheters, other electrophysiology equipment, a power source, and a workstation 53 for controlling the operation of the system 10. The electrophysiology equipment of the system 10 may include, for example, a plurality of catheters, a positioning pad 25, surface ECG electrodes 18, electrode patches 38, an ablation energy generator 50, and a recorder 11. Optionally and preferably, the PIU 30 additionally includes processing capabilities for enabling real-time calculation of the position of the catheters and for performing ECG calculations.

[0042] The workstation 53 includes a memory, a processor unit having a memory or storage device storing appropriate operating software, and user interface capabilities. The workstation 53 can provide a variety of functions, optionally including (1) displaying a current PFA index 51 calculated based on the force and position of the catheter 14, and a predicted PFA index 52 on the display device 27; (2) simulating the endocardial anatomy in three dimensions (3D) and drawing a model or anatomical map 20 for display on the display device 27; (3) displaying an activation sequence (or other data) compiled from a recorded electrogram 21 on the display device 27 with representative visual markers or images superimposed on the drawn anatomical map 20; (4) displaying the real-time position and orientation of multiple catheters within the heart chamber, and (5) displaying locations of interest on the display device 27, such as locations where ablation energy has been applied. A commercial product embodying elements of the system 10 is the CARTO 1000, available from Biosense Webster, Inc., 31A Technology Drive, Irvine, CA 92618. TM 3 systems.

[0043] In some embodiments, the model or anatomical map 20 may indicate thereon the PFA ablation index or a prediction thereof for a plurality of locations within the heart.

[0044] In some embodiments, an index may be displayed for areas where the electrode has applied force on the heart wall, and indicate a predicted PFA ablation index based on the force applied at each such location.

[0045] In other embodiments, the index can be displayed for all areas of the heart wall and indicate the predicted PFA ablation index calculated based on the average predetermined force so that the physician can choose the best location. In some embodiments, the average force used for prediction can be a parameter learned by each physician, such as the force that the physician typically applies during ablation.

[0046] Reference now Figure 2 , a flowchart showing steps in a method for calculating, displaying, and utilizing a predicted PFA index according to some exemplary embodiments of the present disclosure.

[0047] At step 204, a force estimate or measurement may be obtained from a force sensor located at the distal end of the shaft and measures the force with which the physician presses the catheter against the body tissue.

[0048] In some embodiments, when evaluating force, the local force applied by the electrodes of the electrode pair activated under the current protocol can be considered, for example, the sum of the forces applied by the electrodes, the average value of the forces applied by any one of the electrodes, the maximum value, etc.

[0049] In other embodiments, the force may be calculated based on the sum, average maximum, or any other measurement of the forces applied by all electrodes. Optionally, the force is the force sensed on the distal end of the shaft proximal to where the distal end assembly connects to the shaft.

[0050] At step 208, a predicted PFA ablation index may be calculated that predicts the PFA ablation index that would be obtained by applying a predetermined number of electrical pulses or pulse trains having a predetermined amplitude and a predetermined duration at the location when the electrode applies an amount of force to the tissue equal to the assessed force.

[0051] Once the ablation is applied, the predicted PFA ablation index can be calculated using the same calculation used to calculate the actual PFA AI. The important variable in this calculation is the force applied by the catheter on the heart wall, which the physician can influence. The calculation includes other parameters including: the number of pulses to be applied and their corresponding amplitude and duration according to a generally predefined applicable protocol; patient-specific information if available, otherwise generic information based on the general structure of the heart; and specific locations within the heart and their characteristics, such as tissue thickness at the relevant location, tissue type, its conductivity, etc.

[0052] The position information can be global to the catheter or specific to each electrode. In the latter case, the predicted PFA ablation index can combine the force applied to each active electrode and the characteristics of the specific location where the electrode contacts the body tissue.

[0053] Ablation index via PFA is described and shown in U.S. Patent Application Publication US20210186604A1, the entire contents of which are incorporated herein by reference.

[0054] In order to predict and control ablation therapy, the PFA AI can be calculated and displayed to the user. For PFA ablation, a possible scale may correspond to a magnitude S indicating the depth of the lesion, which may depend on F, P, and T, where F is the force applied to the tissue by the catheter, P is the power consumed during the ablation procedure; and T is the time of the procedure, derived from the number of pulses and pulse train repetitions. In some embodiments, an estimate of the magnitude S can be given by finding the integral of an expression including a function of F, P, and T over time.

[0055] This estimate can be applied during PFA so that when the desired lesion size and / or PFA AI is reached, PFA can be stopped.

[0056] In an exemplary embodiment of the present disclosure, the PFA AI may be derived by calculating the sum of the product of the contact force and the number of repetitions over a period of time.

[0057] PFA AI can be calculated according to the following formula:

[0058]

[0059] Where N is equal to the number of PFA pulses applied (hereinafter referred to as "PFA application") and has a predetermined maximum value. It can be understood that each pulse application will increase the total PFA AI.

[0060] AI n is the ablation index for the nth applied pulse and is equal to the lesion depth multiplied by a factor A, where the depth is a logarithmic function of the specific applied force (Force(n)) such that:

[0061] AI n =A*B n *ln(force(n))+Cn; and

[0062] AI n-1 =A*B n-1 *ln(force(n))+C n-1

[0063] Where A is a number within a predetermined range,

[0064] B n is a predefined parameter determined by:

[0065] B n =B0*ln(n)+B1

[0066] where B0 and B1 are predefined constants, and

[0067] C n is a predefined parameter determined by:

[0068] C n =C0*exp(C1*n)

[0069] Where C0 and C1 are predefined constants.

[0070] A.B n and C n The values ​​may be determined empirically for each application iteration and calibrated for each type of catheter and type of cardiac structure and given tissue characteristics.

[0071] It should be noted that for each iteration the AI n and AI n-1 , so that when used in the nth iteration, AI n-1 The value of is not taken from the previous calculation. The displayed PFA can also be updated accordingly with each application.

[0072] The predicted PFA AI can be calculated similarly. However, since the applied force is assumed to be constant across all applications, the formula simplifies to:

[0073] Predicted PFA AI = AI N -AI1

[0074] in

[0075] AI1=A*B1+ln(force)+C1

[0076] AI N =A*B N *ln(force)+C N

[0077] Force is a measure of the force applied by the catheter at the prediction time and is assumed to be constant across all applications,

[0078] B N =B0*ln(N)+B1, and

[0079] C N =C0*exp(C1*N).

[0080] In some embodiments, both the PFA AI and the predicted PFA AI can be provided to the user as a dimensionless number or a range of dimensionless numbers between a minimum and a maximum value representing less than ideal ablation and ideal lesions, respectively. In one example, the ablation index is a dimensionless scale between two extremes, such as 0 and 1000, 250 and 850, etc.

[0081] It should be noted that for actual PFA, AI is calculated for each application n and AI n-1 , so that when used in the nth iteration, AI n-1 The value of is not taken from a previous calculation. The displayed PFA may also be updated accordingly with each application. However, the predicted AI is calculated based on the measured instantaneous force for a predefined number of applications and the predicted AI is the value displayed.

[0082] Based on the predicted ablation index, the physician may decide for or against ablation or repeat ablation at a particular location, and / or the physician may decide whether a greater or lesser contact force is desired during ablation.

[0083] At step 212, the predicted PFA ablation index may be displayed to a user of the system (such as a physician), for example as shown in text 51 of Fig. 1. Optionally, the predicted PFA ablation index is displayed together with the actual PFA ablation index.

[0084] Additionally or alternatively, a map of the heart can be updated, wherein each of a plurality of locations on the map can be associated with and display a predicted PFA index calculated when the physician brings the catheter into contact with the heart tissue. The map can be color-coded, shaded, pattern-coded, etc.

[0085] Additionally or alternatively, a map of the heart may be displayed that shows a generic map of predicted PFA ablation indices for multiple locations based on the type of tissue and its thickness. The map may display indices based on generic predetermined forces or typical forces applied by the physician, as learned from the physician's current or previous sessions.

[0086] The calculation and display may be updated every predetermined period of time, such as every second, every 5 seconds, etc. In alternative embodiments, the calculation and display may be updated continuously, such as each time the catheter is moved.

[0087] At step 216, optionally based on the user's instructions, or based on confirmation of a displayed notification, the generator may be operated by the user, and IRE energy may be supplied to the electrodes, and thus to the tissue, according to the applicable protocol. Thus, a predetermined number of current pulses of a predetermined width are supplied to the relevant electrodes, and thus to the location, to produce ablation.

[0088] At step 220, where ablation has been performed, an actual PFA ablation index may be calculated and displayed. Typically, the actual PFA AI is calculated on a per application basis, and the cumulative PFA AI is displayed as ablation is performed after each application.

[0089] In some embodiments, after application, the actual PFA ablation index can be compared to the predicted value to obtain at least one difference value.

[0090] In some embodiments, the comparison results including at least one difference can be used to learn prediction parameters so that future predictions are more accurate. For example, if the predicted value is always higher or lower than the actual value, the predicted value can be reduced or increased accordingly. In further cases, more complex relationships between any two or more of the applied force, tissue features, catheter structure, and the applied protocol can be learned. The learning can be performed automatically by a processor, manually by an operator, or in a hybrid manner.

[0091] Reference now Figure 3 , shows a block diagram of a computing platform 300 for calculating, displaying, and utilizing a predicted PFA ablation index according to some exemplary embodiments of the present disclosure.

[0092] It should be understood that the computing platform 300 may be embedded within the console 30 or the workstation 53 , but may also be a standalone computing platform or embedded elsewhere and in operable communication with the console 30 .

[0093] The computing platform 300 may be implemented as one or more computing platforms that are operably connected to each other. For example, one or more remote computing platforms may be implemented, for example, on a cloud computer. Other computing platforms may be part of a computer network of an associated organization. In other embodiments, all functions may be provided by one or more computing platforms that are all part of an organization's network.

[0094] The computing platform 300 may include one or more processors 304, which may be one or more central processing units (CPUs), microprocessors, electronic circuits, integrated circuits (ICs), etc., located or not located on the same computing platform. The processor 304 may be configured to provide the desired functionality, for example, by loading into memory and activating software modules stored on the storage device 312, which are described in detail below.

[0095] The computing platform 300 may include input / output (I / O) devices 306, such as a display, a pointing device, a keyboard, a touch screen, a speaker, a microphone, etc. The I / O devices 306 may be used to receive input from a user (such as a physician) and provide output thereto, such as displaying a predicted PFA ablation index, receiving operation instructions, etc.

[0096] The computing platform 300 may include a communication device 308 for communicating with other devices or other computing platforms, such as obtaining pressure information from a force sensor, obtaining operational information from a catheter insertion controller, storing data on a remote storage device, etc. The communication module 308 may be adapted to interface with any communication channel (such as a local area network (LAN), a wide area network (WAN), a cellular network, etc.), and use any relevant communication protocol.

[0097] The computing platform 300 may include a storage device 312, such as a hard drive, a flash drive, a random access memory (RAM), a memory chip, etc. In some exemplary embodiments, the storage device 312 may retain program code that is operable to cause the processor 304 to perform operations related to any one or more of the modules listed below. Figure 2 The program code may include one or more executable units, such as functions, libraries, independent programs, etc., adapted to perform instructions as described in detail below.

[0098] Alternatively or additionally, the provided instructions may be stored on a non-transitory tangible computer-readable medium, such as a magnetic, optical or electronic memory.

[0099] The storage device 312 may include a communication module 316 for transmitting data to and receiving data from other systems (such as a catheter control system, force sensors, external storage devices, display systems, etc.) via the communication device 308. In particular, the communication module 316 may be used to receive force measurements from one or more force sensors associated with the catheter (e.g., located at the distal end of the catheter).

[0100] The storage device 312 may include a PFA ablation index prediction module 320 for calculating a prediction index based on the sensed force, electrode and signal parameters, and optionally location, as described in detail above in connection with step 208 .

[0101] The storage device 312 may include a PFA ablation index comparison module 324 for comparing the predicted PFA ablation index with an actual PFA ablation index measured at a post-ablation location.

[0102] The storage device 312 may include a PFA prediction parameter learning module 328 for adjusting the parameters or calculations of the PFA ablation index prediction module 320 based on the difference between the predicted PFA ablation index and the actual PFA ablation index. Thus, the PFA ablation index prediction module 328 may adjust its internal parameters or calculations so that future predictions will more closely predict actual results, enabling the physician to better decide where to perform ablation and how much force to apply during ablation. The learning of the parameters may be performed automatically, manually, or a combination thereof.

[0103] The storage device 312 may include a data and control flow management module 332 for activating the above modules in the correct order and with the required inputs, such as activating the PFA prediction parameter learning module 328 after the information of the predicted PFA ablation index and the actual PFA ablation index is available for multiple locations.

[0104] The storage device 312 may include a user interface 336 for presenting to the user a display to be displayed on the display device 27, such as a predicted PFA ablation index 51, a cardiac-indicative ablation index or a predicted map thereof, etc. The user interface 336 may also be used to receive instructions and operating parameters from a user-operated controller 32, etc.

[0105] It should be understood that the steps and modules disclosed above are in addition to the software, hardware, firmware or other modules required to operate the catheter, display the catheter insertion process, perform other calculations (such as complex fractionated electrogram (CFE) analysis), generate cardiac mapping, etc. Further details of the method and system can be found in, for example, US8676305, US9629567, the entire contents of which are incorporated herein by reference for any purpose.

[0106] The present invention may be a system, method and / or computer program product. The computer program product may include a computer-readable storage medium (or multiple media) having computer-readable program instructions thereon, which are used to cause a processor to perform various aspects of the present invention.

[0107] A computer-readable storage medium may be a tangible device that can retain and store instructions for use by an instruction execution device. A computer-readable storage medium may be, for example, but not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. An incomplete list of more specific examples of computer-readable storage media includes the following: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as a punch card or a raised structure in a groove with instructions recorded thereon, and any suitable combination of the foregoing. As used herein, a computer-readable storage medium should not be understood as a transient signal itself, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse passing through a fiber optic cable), or an electrical signal transmitted by a wire.

[0108] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to a corresponding computing / processing device, or downloaded to an external computer or external storage device via a network (e.g., the Internet, a local area network, a wide area network, and / or a wireless network). The network may include copper transmission cables, transmission optical fibers, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions to be stored in a computer-readable storage medium in the corresponding computing / processing device.

[0109] The computer-readable program instructions for performing the operation of the present invention may be assembly instructions, instruction set architecture instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages ​​(such as programming languages ​​of Java, C, C++, Python, etc.). The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, executed as an independent software package, partially on the user's computer and partially on a remote computer, or completely on a remote computer or server. In the latter case, the remote computer may be connected to the user's computer via any type of network (including a local area network (LAN) or a wide area network (WAN)), or may be connected to an external computer (e.g., by using the Internet of an Internet service provider). In some embodiments, in order to perform various aspects of the present invention, an electronic circuit including, for example, a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA) may execute a computer-readable program instruction to personalize the electronic circuit by utilizing the state information of the computer-readable program instructions.

[0110] Various aspects of the present invention are described herein with reference to flowchart illustrations and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present invention. It should be understood that each box in the flowchart illustration and / or block diagram and the combination of boxes in the flowchart illustration and / or block diagram can be implemented by computer-readable program instructions.

[0111] These computer-readable program instructions may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device create a tool for implementing the functions / actions specified in one or more boxes of the flowchart and / or block diagram. These computer-readable program instructions may also be stored in a computer-readable storage medium, which may guide a computer, a programmable data processing device, and / or other devices to work in a specific manner, so that the computer-readable storage medium having the instructions stored therein includes a product having instructions for implementing various aspects of the functions / actions specified in one or more boxes of the flowchart and / or block diagram.

[0112] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing device, or other apparatus, so that a series of operational steps are performed on the computer, other programmable device, or other apparatus to produce a computer-implemented process, so that the instructions executed on the computer, other programmable device, or other apparatus implement the functions / actions specified in one or more boxes of the flowchart and / or block diagram.

[0113] The flow charts and block diagrams in the accompanying drawings illustrate the possible specific implementation architecture, functions and operations of the system, method and computer program product according to various embodiments of the present invention. In this regard, each box in the flow chart or block diagram may represent a module, a fragment or a part of an instruction, and the instruction includes one or more executable instructions for implementing a specified logical function. In some alternative specific implementations, the function indicated in the box may not occur in the order indicated in the accompanying drawings. For example, depending on the function involved, the two boxes shown in succession may actually be executed substantially simultaneously, or the box may sometimes be executed in the opposite order. It should also be noted that each box in the block diagram and / or the flow chart diagram and the combination of the boxes in the block diagram and / or the flow chart diagram can be implemented by a system based on special-purpose hardware that performs a specified function or action or by a combination of special-purpose hardware and computer instructions.

[0114] Example

[0115] Example 1

[0116] A method comprises: receiving input from a force sensor on a catheter, the catheter including an electrode for ablating a patient's heart, the catheter being placed at a location within the heart; calculating a predicted PFA ablation index (PFA AI) for ablation based at least on the received input, the predicted PFA ablation index (PFA AI) being caused by the catheter applying a force equal to an assessed force at the location to achieve a predetermined number of electrical pulses having a predetermined amplitude and a predetermined duration, wherein the calculation conforms to a predefined formula; and displaying the predicted PFA AI to a user of the catheter.

[0117] Example 2

[0118] The method according to Example 1 further includes: receiving updated input from the force sensor; and repeating the calculating and the displaying for the updated input.

[0119] Example 3

[0120] The method according to example 1 further comprises displaying, alongside the predicted PFA ablation index, an actual PFA AI calculated after ablation has been performed with an actual force measured during application.

[0121] Example 4

[0122] A method as in example 1, wherein the calculating is equal to the calculating of the PFA AI once ablation is applied with a force equal to the evaluation.

[0123] Example 5

[0124] A method as in Example 1, wherein the predicted PFA AI calculation is based on a location on a wall of the heart.

[0125] Example 6

[0126] The method of Example 1, wherein the predicted PFA AI calculation is based on tissue type, tissue thickness, or tissue conductivity of tissue at the location on the wall of the heart.

[0127] Example 7

[0128] The method of Example 1, wherein the predicted PFA AI calculation is based on characteristics of an electrode or an applied signal.

[0129] Example 8

[0130] The method of Example 1, wherein calculating the predicted PFA AI is based on the following formula:

[0131] Predicted PFA AI = AI N -AI1

[0132] in

[0133] AI1=A*B1+ln(force)+C1

[0134] AI N =A*B N *ln(force)+C N

[0135] N is equal to the number of PFA pulses applied,

[0136] Force is a measure of the force applied by the catheter at the prediction time and is assumed to be constant across all applications,

[0137] B N =B0*ln(N)+B1,

[0138] C N =C0*exp(C1*N),

[0139] A is a number within a predetermined range, and

[0140] B0, B1, C0, and C1 are predefined constants.

[0141] Example 9

[0142] A method according to Example 8, wherein A, B0, B1, C0 and C1 are determined empirically for each catheter type, and type of cardiac structure and given tissue characteristics at the location.

[0143] Example 10

[0144] A computerized device having a processor coupled to a storage unit, the processor being adapted to perform the following steps: receiving input from a force sensor on a catheter, the catheter comprising an electrode for ablating a patient's heart, the catheter being placed at a location within the heart; calculating a predicted PFA ablation index (PFA AI) for ablation based at least on the received input, the predicted PFA ablation index (PFA AI) being caused by the catheter applying a force equal to an assessed force at the location to achieve a predetermined number of electrical pulses having a predetermined amplitude and a predetermined duration, wherein the calculation conforms to a predefined formula; and displaying the predicted PFA AI to a user of the catheter.

[0145] Example 11

[0146] The method as described in Example 10, wherein the device processor is further adapted to perform: receiving updated input from the force sensor; and repeating the calculating and the displaying for the updated input.

[0147] Example 12

[0148] As described in Example 10, wherein the processor is further adapted to display, alongside the predicted PFA ablation index, an actual PFA AI calculated by the device after ablation has been performed with an actual force measured during application.

[0149] Example 13

[0150] The apparatus of Example 10, wherein the calculation is equal to the calculation of the PFA AI once ablation is applied with a force equal to the assessment.

[0151] Example 14

[0152] The apparatus of Example 10, wherein the predicted PFA AI calculation is based on a location on the wall of the heart.

[0153] Example 15

[0154] The apparatus of Example 10, wherein the predicted PFA AI calculation is based on tissue type, tissue thickness, or tissue conductivity of tissue at a location on the wall of the heart.

[0155] Example 16

[0156] The apparatus of Example 10, wherein the predicted PFA AI calculation is based on characteristics of the electrode or the applied signal.

[0157] Example 17

[0158] The apparatus of example 10, wherein calculating the predicted PFA AI is based on the following formula:

[0159] Predicted PFA AI = AI N -AI1

[0160] in

[0161] AI1=A*B1+ln(force)+C1

[0162] AI N =A*B N *ln(force)+C N

[0163] N is equal to the number of PFA pulses applied,

[0164] Force is a measure of the force applied by the catheter at the prediction time and is assumed to be constant across all applications,

[0165] B N =B0*ln(N)+B1,

[0166] C N =C0*exp(C1*N),

[0167] A is a number within a predetermined range, and

[0168] B0, B1, C0, and C1 are predefined constants.

[0169] Example 18

[0170] As described in Example 10, wherein A, B0, B1, C0 and C1 are determined empirically for each catheter type, and type of cardiac structure and given tissue characteristics at the device location.

[0171] Example 19

[0172] A computer program product comprising a non-transitory computer-readable medium retaining program instructions, which instructions, when read by a processor, cause the processor to perform: receiving input from a force sensor on a catheter, the catheter comprising electrodes for ablating a patient's heart, the catheter being placed at a location within the heart; calculating a predicted PFA ablation index (PFA AI) for ablation based at least on the received input, the predicted PFA ablation index (PFA AI) to be caused by the catheter applying a force equal to an assessed force at the location to achieve a predetermined number of electrical pulses having a predetermined amplitude and a predetermined duration, wherein the calculation conforms to a predefined formula; and displaying the predicted PFA AI to a user of the catheter.

[0173] Example 20

[0174] A computer program product according to example 19, wherein calculating the predicted PFA AI is based on the following formula:

[0175] Predicted PFA AI = AI N -AI1

[0176] in

[0177] AI1=A*B1+ln(force)+C1

[0178] AI N =A*B N *ln(force)+C N

[0179] N is equal to the number of PFA pulses applied,

[0180] force is the measured value of the force applied by the catheter at the predicted time and is assumed to be constant across all applications,

[0181] B N =B0*ln(N)+B1,

[0182] C N =C0*exp(C1*N),

[0183] A is a number within a predetermined range, and

[0184] B0, B1, C0, and C1 are predefined constants.

[0185] Although the examples described herein are primarily directed to cardiac diagnostic applications, the methods and systems described herein may also be used in other medical applications.

[0186] It should be understood that the above examples are cited by way of example, and the present disclosure is not limited to what is specifically shown and described above. On the contrary, the scope of the present disclosure includes combinations and sub-combinations of the aforementioned various features and their variations and modifications, which should be expected by those skilled in the art when reading the above description and which are not disclosed in the prior art.

Claims

1. A method comprising: receiving input from a force sensor on a catheter comprising a catheter for ablating a patient 5. calculating a predicted PFA ablation index (PFA AI) for ablation based at least on the received input, the predicted PFA ablation index (PFA AI) to be calculated by the catheter. The tube applies a force equal to the estimated force at the position to achieve a predetermined magnitude and a predetermined A predetermined number of electrical pulses of a predetermined duration is caused, wherein the meter Calculating conformity to a predefined formula; and 10 displaying the predicted PFA AI to a user of the catheter.

2. The method according to claim 1, further comprising: receiving updated input from the force sensor; as well as The calculating and the displaying are repeated for the updated input.

3. The method of claim 1, further comprising displaying, next to the predicted PFA ablation index, an actual PFA AI calculated after ablation has been performed with the actual force measured during application.

4. The method according to claim 1, wherein: The calculation is equal to once the evaluation Calculation of AI for PFA after equal force application ablation.

5. The method according to claim 1, wherein: The predicted PFA AI calculation is based on the location on the wall of the heart.

6. The method according to claim 1, wherein: The predicted PFA AI calculation is based on the The tissue type, tissue thickness, or Tissue conductivity.

7. The method according to claim 1, wherein: The predicted PFA AI calculation is based on characteristics of the electrodes or applied signals.

8. The method according to claim 1, wherein: The predicted PFA AI is calculated based on The following formula: Predicted PFA AI = AI N -AI1 30 of which AI1=A*B1+ln(force)+C1, Aly=A*By*ln(force)+CN N is equal to the number of PFA pulses applied, Force is a measure of the force applied by the catheter at the predicted time and is assumed to be constant across all applications, B N =B0*ln(N)+B1, C N =C0*exp(C1*N), A is a number within a predetermined range, and B0, B1, C0, and C1 are predefined constants.

9. The method according to claim 8, wherein: For each catheter type, and type of cardiac structure and given tissue characteristics at the location, A, B0, B1, C0, and C1 are determined empirically.

10. A computerized device having a processor coupled to a memory unit, the processor being adapted to perform the following steps: receiving input from a force sensor on a catheter including electrodes for ablating a heart of a patient, the catheter being placed at a location within the heart; calculating, based at least on the received input, a predicted PFA ablation index (PFA AI) for ablation that would result from application by the catheter at the location of a force equal to the assessed force to achieve a predetermined number of electrical pulses having a predetermined amplitude and a predetermined duration, wherein The calculation complies with a predefined formula; and The predicted PFA AI is displayed to a user of the catheter.

11. The device according to claim 10, wherein: The processor is further adapted to execute: receiving updated input from the force sensor; and The calculating and the displaying are repeated for the updated input.

12. The device according to claim 10, wherein: The processor is further adapted to display, next to the predicted PFA ablation index, an actual PFA AI calculated after ablation has been performed with the actual force measured during application.

13. The apparatus according to claim 10, wherein: The calculation is equal to the calculation of the PFA AI once ablation is applied with a force equal to the evaluation.

14. The apparatus according to claim 10, wherein: The predicted PFA AI calculation is based on the location on the wall of the heart.

15. The apparatus according to claim 10, wherein: The predicted PFA AI calculation is based on tissue type, tissue thickness, or tissue conductivity of tissue at the location on the wall of the heart.

16. The apparatus according to claim 10, wherein: The predicted PFA AI calculation is based on characteristics of the electrodes or applied signals.

17. The apparatus according to claim 10, wherein: The predicted PFA AI is calculated based on the following formula: Predicted PFA AI = AI N -AI1 in AI1=A*B1+ln(force)+C1 AlN=A*BN*ln(force)+CN N is equal to the number of PFA pulses applied, force is the measured value of the force applied by the catheter at the predicted time and is assumed to be constant across all applications, B N =B0*ln(N)+B1, C N =C0*exp(C1*N), A is a number within a predetermined range, and B0, B1, C0, and C1 are predefined constants.

18. The apparatus according to claim 17, wherein: For each catheter type, and type of cardiac structure and given tissue characteristics at the location, A, B0, B1, C0, and C1 are determined empirically.

19. A computer program product comprising a non-transitory computer readable medium retaining program instructions which, when read by a processor, cause the processor to execute: receiving input from a force sensor on a catheter including electrodes for ablating a heart of a patient, the catheter being placed at a location within the heart; calculating, based at least on the received input, a predicted PFA ablation index (PFA AI) for ablation that would result from application by the catheter at the location of a force equal to the assessed force to achieve a predetermined number of electrical pulses having a predetermined amplitude and a predetermined duration, wherein The calculation complies with a predefined formula; and The predicted PFA AI is displayed to a user of the catheter.

20. The computer program product of claim 19, wherein: The predicted PFA AI is calculated based on the following formula: Predicted PFA AI = AI N -AI1 in AI1=A*B1+ln(force)+C1 AIN=A*BN*ln(force)+CN N is equal to the number of PFA pulses applied, force is the measured value of the force applied by the catheter at the predicted time and is assumed to be constant across all applications, B N =B0*ln(N)+B1, C N =C0*exp(C1*N), A is a number within a predetermined range, and B0, B1, C0, and C1 are predefined constants.

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