Electroanatomical mapping without acquiring reference signals

Abstract

Systems and methods for generating an electroanatomical map of a heart are disclosed. The disclosed techniques include measuring a plurality of sets of activation signals. The activation signal in each set of activation signals is measured by a respective electrode of a mapping catheter placed at a respective location in the heart. Wherein at least one electrode of the mapping catheter that measures an activation signal in one set of activation signals spatially overlaps a corresponding electrode of the mapping catheter that measures an activation signal in the other set of activation signals. The disclosed technique also includes obtaining a respective set of time measurements using overlapping electrodes based on the plurality of sets of activation signals. And constructing an electroanatomical map based on the obtained set of time measurements.

Description

Background Art

[0001] A three-dimensional (3D) electroanatomical map of the heart is used to visualize cardiac tissue conduction and the propagation of electrical signals across the endocardium. Activation signals (electrograms) can be acquired by a mapping catheter that measures those signals at various locations on the endocardium. In order to detect the activation time at a specific cardiac tissue location, the activation signal (measured at that location) is compared with a reference activation signal. Typically, the reference activation signal captures the electrical activity generated by the source (e.g., the sinoatrial node) through a dedicated reference catheter placed near the source (e.g., the coronary sinus (CS)). However, in some patients, the physician cannot insert the reference catheter into the CS. In addition, in some patients, inserting multiple catheters (e.g., a reference catheter, a mapping catheter, and possibly an ablation catheter) into the femoral vein anatomy proves to be challenging.

[0002] Furthermore, in some cases, the reference catheter cannot be fixed at one location, so that a moving spatiotemporal reference frame can be prevented. In other cases, the myocardium measured by the reference catheter can be electrically separated from the region being mapped, making the use of a reference catheter unhelpful in generating a 3D electroanatomical map.

[0003] Therefore, there is a need for a technique for generating a 3D electroanatomical map without the need to insert a reference catheter to acquire a reference activation signal. Such a technique would allow cardiac mapping using a single mapping catheter with a single cardiac access point. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] A more detailed understanding may be obtained from the following detailed description provided by way of example in conjunction with the accompanying drawings, in which like reference numerals indicate like elements, and in which:

[0005] Figure 1 is an illustration of an example cardiac mapping system upon which one or more features of the present disclosure may be implemented;

[0006] Figure 2 is able to be Figure 1 A block diagram of an example system for an example cardiac mapping system deployment based on which one or more features of the present disclosure may be implemented;

[0007] Figure 3 An example catheter is shown upon which one or more features of the present disclosure may be implemented;

[0008] Figure 4 An example balloon catheter is shown upon which one or more features of the present disclosure may be implemented;

[0009] Figure 5 An example annular conduit is shown upon which one or more features of the present disclosure may be implemented;

[0010] Figure 6 An example method for electroanatomical mapping using a mapping catheter and a reference catheter is shown, based on which one or more features of the present disclosure may be implemented;

[0011] Figure 7 An example method for electroanatomical mapping using a mapping catheter is shown, based on which one or more features of the present disclosure may be implemented;

[0012] Figure 8 An example method for combining a set of measurements acquired by a mapping catheter is shown, based on which one or more features of the present disclosure may be implemented; and

[0013] Fig. 9 is a flow chart of an example method for generating an electroanatomical map of a heart, upon which one or more features of the present disclosure may be implemented. DETAILED DESCRIPTION

[0014] As disclosed herein, a multi-electrode mapping catheter can be used to generate a 3D electroanatomical map, such as a local arrival time (LAT) map of a chamber of the heart. This can be accomplished without the use of an additional catheter to acquire reference activation signals. To this end, multiple sets of activation signals can be acquired, one set of which can be measured by the electrodes of the mapping catheter when placed at corresponding locations on the endocardium. A set of time measurements can then be derived from the corresponding multiple sets of activation signals. The time measurements of one set are related to the time measurements of another set by the measurements in the two sets corresponding to the activation signals measured by the spatially overlapping electrodes. Aspects of the 3D electroanatomical mapping described herein can be performed by a cardiac mapping system, such as a 3 3D system). Generally speaking, a cardiac mapping system can provide a 3D visualization of the cardiac anatomy superimposed with, for example, a LAT map that visualizes the electrical properties of the heart. Figures 1 to 5 Mapping systems are described that can be used to employ aspects of 3D electroanatomical mapping.

[0015] Aspects of the present disclosure describe a method for generating an electroanatomical map of the heart. The method includes measuring multiple groups of activation signals. The activation signals of each group are measured by corresponding electrodes of a mapping catheter placed at corresponding positions in the heart, wherein at least one electrode of the mapping catheter that measures the activation signals of one of the multiple groups overlaps spatially with a corresponding electrode of the mapping catheter that measures the activation signals of another group of the multiple groups. The method also includes obtaining a corresponding set of time measurements based on the multiple groups of activation signals using the overlapping electrodes. Then, an electroanatomical map is constructed based on the obtained set of time measurements.

[0016] Aspects of the present disclosure also describe a system for generating an electroanatomical map of the heart. The system includes at least one processor and a memory storing instructions. These instructions, when executed by the at least one processor, cause the system to measure multiple groups of activation signals. The activation signals of each group are measured by corresponding electrodes of a mapping catheter placed at corresponding positions in the heart, wherein at least one electrode of the mapping catheter that measures the activation signals of one of the multiple groups overlaps spatially with a corresponding electrode of the mapping catheter that measures the activation signals of another group of the multiple groups. These instructions also cause the system to obtain corresponding sets of time measurements based on the multiple groups of activation signals using the overlapping electrodes, and then construct an electroanatomical map based on the obtained sets of time measurements.

[0017] In addition, aspects of the present disclosure describe a non-transitory computer-readable medium that includes instructions that can be executed by at least one processor to perform a method for generating an electroanatomical map of the heart. The method includes measuring multiple groups of activation signals. The activation signals of each group are measured by corresponding electrodes of a mapping catheter placed at corresponding positions in the heart, wherein at least one electrode of the mapping catheter that measures the activation signals of one of the multiple groups overlaps spatially with the corresponding electrode of the mapping catheter that measures the activation signals of another group of the multiple groups. The method also includes obtaining a corresponding set of time measurements based on the multiple groups of activation signals using the overlapping electrodes. Then, an electroanatomical map is constructed based on the obtained set of time measurements.

[0018] Figure 1 is an illustration of an exemplary cardiac mapping system 100 upon which one or more features of the present disclosure may be implemented. System 100 may include a console 124, a display 127, and a catheter 140 operated by a user (e.g., a physician or medical professional) 130. System 100 may be configured to obtain anatomical and electrical measurements taken from an organ (such as heart 126) of patient 128, visualize the obtained anatomical and electrical measurements, and perform cardiac ablation procedures. Inset 145 shows catheter 140 in an enlarged view, and inset 125 shows catheter 140 within a cardiac chamber of heart 120. An example of system 100 is a Biosense Webster's 3 3D mapping system.

[0019] Figure 1The catheter 140 shown in this article is represented as one or more catheters that can be used by the system 100, including ablation catheters and mapping catheters. The ablation catheter can be configured to damage (ablate) a tissue area of ​​an organ in the body. The mapping catheter equipped with one or more electrodes can be configured to obtain biometric data including electrical signals. The system 100 may include one or more probes 121, which have a shaft 122 that can be navigated by a physician 130 to a body part (such as a heart 126) of a patient 128 lying on a table 129. The physician 130 can insert the shaft 122 through the sheath 123, while using a manipulator near the proximal end of the catheter 140 and / or deflecting from the sheath 123 to manipulate the distal end of the shaft 122. As shown in 145, the catheter 140 can be mounted at the distal end of the shaft 122. The catheter 140 can be inserted through the sheath 123 in a collapsed state and can then be deployed in the heart 126.

[0020] In one aspect, the electrical properties of the heart (e.g., biometric data derived from electrical signals acquired by the electrodes of the catheter) can represent information associated with, for example, LAT, electrical activity, topology, unipolar or bipolar voltage, dominant frequency, or impedance. LAT can represent the time at which electrical activity has been measured at a certain location. LAT can be calculated based on a normalized initial starting point that can be derived from a reference catheter. Electrical activity can be any applicable electrical signal that can be measured based on one or more thresholds. Electrical activity can be enhanced (e.g., using a filter to improve the signal-to-noise ratio). Topology can represent the physical structure of a body part or a part of a body part, or can correspond to changes in physical structure between different parts of a body part or between different body parts. The dominant frequency can represent a frequency or frequency range that is prevalent in a part of a body part, and can be different in different parts of the same body part. For example, the dominant frequency of the pulmonary veins in the heart can be different from the dominant frequency of the right atrium of the same heart. Impedance can represent the resistance at a given area of ​​a body part.

[0021] The console 124 of the system 100 may include a processing unit 141, a memory 142, and a communication interface circuit 138. The processing unit 141 may be a computer equipped with a multi-core processor, and may include a front end and a control component. The memory 142 may include a volatile memory and a non-volatile memory. The communication interface circuit 138 may be used to transmit signals to and receive signals from the catheter 140. The console 124 may be configured to receive biometric data, then process, visualize and store the biometric data for later processing, or transmit the data to another system via a network. In one aspect, the processing unit 141 may be located outside the console 124, and may be located, for example, in the catheter 140, in an external device, in a mobile device, in a cloud-based device, or may be an independent processor. The processing unit 141 may execute software modules that are programmed to perform the functions of various aspects described herein. These software modules may be downloaded to the processing unit 141 via a network or from a non-temporary tangible medium (such as a magnetic memory, an optical memory, or an electronic memory) external or local to the console 124.

[0022] The system 100 may be modified to implement the various aspects disclosed herein. The various aspects disclosed herein may be similarly applied using other system components and settings. In addition, the system 100 may include additional components, such as elements for sensing electrical activity, wired or wireless connectors, processing units, or display devices. The console 124 may include a real-time noise reduction circuit system that is typically configured as a field programmable gate array (FPGA), followed by an analog-to-digital (A / D) ECG (electrocardiogram) or EMG (electromyogram) signal conversion integrated circuit. The output of the A / D ECG or EMG circuit may be processed to perform the methods disclosed herein.

[0023] The console 124 may be connected to body surface electrodes 143 via cables 139, which may include adhesive skin patches attached to the patient 128. The processing unit 141 in conjunction with the tracking module may determine the position coordinates of the catheter 140 within a body part (e.g., the heart 126) of the patient 128. The position coordinates may be based on impedance or electromagnetic fields measured between the body surface electrodes 143 and the electrodes (or other electromagnetic components of the catheter 140). Additionally or alternatively, the position coordinates may be based on impedance or electromagnetic fields measured between a position pad attached to the surface of the bed 129 and the electrodes (or other electromagnetic components) of the catheter 140.

[0024] During the procedure, the processing unit 141 may facilitate the rendering 135 of the body part 126 on the display 127 for viewing by the physician 130, and may store data representing the body part in the memory 142. In one aspect, the physician 130 may be able to rotate and move the rendered body part 135 (e.g., change the perspective of the rendered body part) using one or more input devices (e.g., a touch screen, a touchpad, a mouse, a keyboard, or a gesture recognition device). For example, the position of the catheter 140 may be changed to collect measurements, based on which the rendering 135 of the body part 126 is updated. In addition, the representation of the catheter may be presented relative to the rendering of the body part to allow the physician 130 to better navigate the catheter within the body part. In one aspect, the display 127 may be located at a remote location, such as at a separate hospital or in a separate healthcare provider network.

[0025] Figure 2 It can be Figure 1 2 is a block diagram of an exemplary system 200 deployed with an exemplary cardiac mapping system 100, based on which one or more features of the present disclosure can be implemented. System 200 may include a monitoring and processing system 205, a local system 280, and a remote system 290. Monitoring and processing system 205 may include a sensor 210, a processor 220, a memory 230, an input device 240, an output device 250, and a transceiver 260 (e.g., a transmitter-receiver that communicates with a network 270). System 205 may continuously or periodically monitor, store, process, and transmit various patient biometric data via network 270. Patient biometric data may include, for example, electrical signals (e.g., ECG signals), anatomical images, blood pressure data, blood glucose data, and temperature data. Patient biometric data may be monitored (processed, visualized, transmitted) to facilitate treatment of various diseases, such as cardiovascular diseases (e.g., arrhythmias, cardiomyopathy, and coronary artery disease) and autoimmune diseases (e.g., type I and type II diabetes).

[0026] In one aspect, the monitoring and processing system 205 may represent Figure 1 The console 124 of the system 100 is shown. In another aspect, the monitoring and treatment system 205 can be located inside the patient's body - for example, the system 205 can be implantable subcutaneously, inserted orally or surgically, inserted intravenously or intraarterially, inserted via an endoscopic or laparoscopic procedure. In yet another aspect, the system 205 can be externally attached to the patient's skin. Alternatively, the system 205 can include components located inside the patient's body and components located outside the patient's body.

[0027] The monitoring and processing system 205 may represent multiple monitoring and processing systems 205 that can process the patient's biometric data in parallel, in communication with each other and / or via a network with a server. One or more systems 205 may acquire or receive all or part of the patient's biometric data (e.g., electrical signals, anatomical images, blood pressure, temperature, blood sugar levels, or other biometric data). The one or more systems 205 may also acquire or receive additional information associated with the acquired or received biometric data of the patient from one or more other systems 205. The additional information may be, for example, diagnostic information and / or information obtained from a device such as a wearable device. Each monitoring and processing system 205 may process the data acquired by it and may process data received from another system 205.

[0028] Sensor 210 may represent one or more sensors that can be configured to sense biometric data from a patient. For example, sensor 210 may be an electrode, temperature sensor, blood pressure sensor, blood glucose sensor, blood oxygen sensor, pH sensor, accelerometer, or microphone configured to acquire electrical signals (e.g., bioelectric signals originating from the heart). In one aspect, system 205 may include an ECG monitoring system that measures ECG signals originating from the heart. In such cases, sensor 210 may include one or more electrodes that can be configured to acquire ECG signals. ECG signals can be used to diagnose and treat various cardiovascular diseases. In one aspect, sensor 210 may include a catheter, a probe, a blood pressure cuff, a weight scale, a bracelet (e.g., a smart watch biometric tracker), a glucose monitor, a continuous positive airway pressure (CPAP) machine, or any other device that provides biometric data or other data about the health of a patient.

[0029] The transceiver 260 may include a transmitter component and a receiver component. These transmitter components and receiver components may be integrated into a single device or implemented separately. The transceiver may provide a connection between the system 205 and other systems or servers via a communication network 270. The network 270 may be a wired network, a wireless network, or a combination of wired and / or wireless networks. The network 270 may be a short-range network (e.g., a local area network (LAN) or a personal area network (PAN)). Various short-range communication protocols (such as Bluetooth, Wi-Fi, Zigbee, Z-Wave, near field communication (NFC), ultra-wideband or infrared (IR)) may be used to send or receive information via the short-range network. The network 270 may also be a long-range network (e.g., a wide area network (WAN), the Internet or a cellular network). Various long-range communication protocols (such as TCP / IP, HTTP, 3G, 4G / LTE or 5G / new radio) may be used to send or receive information via the long-range network.

[0030] The processor 220 may be configured to process biometric data of a patient, such as obtained by the sensor 210, and store the biometric data and / or processed biometric data in the memory 230. The processor 220 may also be configured to transmit the biometric data over the network 270 via the transmitter of the transceiver 260. Biometric data from one or more other monitoring and processing systems 205 may be received by the receiver of the transceiver 260. The processor 220 may employ an algorithm (e.g., an artificial intelligence-based algorithm, such as a machine learning algorithm), or alternatively or in addition, the algorithm may be employed by other processors (e.g., at the local system 280 or the remote system 290). In various aspects, the processor 220 may include one or more CPUs, one or more GPUs, or one or more FPGAs. In these aspects, the algorithm may be executed on one or more of these processing units. Similarly, the processor 220 may include an ASIC (such as a processor) dedicated to performing deep learning calculations. Nervana TM The processing unit that executes the algorithm can be located in the medical procedure room or in another location (e.g., another medical facility or the cloud).

[0031] The input device 240 of the monitoring and processing system 205 can be used as a user interface. The input device 240 can include, for example, a piezoelectric sensor or a capacitive sensor configured to receive user input (such as a tap or touch). Therefore, the input device 240 can be configured to implement capacitive coupling in response to a user tapping or touching the surface of the system 205. Gesture recognition can be implemented through various capacitive couplings, such as resistive capacitance, surface capacitance, projected capacitance, surface acoustic wave, piezoelectric, or infrared touch. The capacitive sensor can be placed on the surface of the input device 240 so that a tap or touch of the surface activates the system 205. The processor 220 can be configured to selectively respond to different tap patterns of the capacitive sensor (e.g., a single or double tap on the input device 240) so that different functions of the system 205 (e.g., acquisition, storage, or transmission of data) can be activated based on the detected pattern. In one aspect, for example, when a gesture is detected and recognized, audible feedback can be given to the user from the system 205.

[0032] A local system 280 that can communicate with the monitoring and processing system 205 via the network 270 can be configured to act as a gateway to a remote system 290 through another network 285 accessible to the local system 280. The local system 280 can be, for example, a smart phone, a smart watch, a tablet computer, or other portable smart device. Alternatively, the local system 280 can be a fixed or stand-alone device. Patient biometric data can be transmitted between the local system 280 and the monitoring and processing system 205. In one aspect, the local system 280 can also be configured to display the acquired patient biometric data and associated information.

[0033] The remote system 290 may be configured to receive at least a portion of the monitored patient biometric data and associated information via the network 285, which may be a remote network. For example, if the local system 280 is a mobile phone, the network 285 may be a wireless cellular network, and information may be transmitted between the local system 280 and the remote system 290 via wireless technology standards such as any of the wireless technologies described above. The remote system 290 may be configured to present the received patient biometric data and associated information to a healthcare professional (e.g., a physician) visually on a display or audibly through a speaker.

[0034] Figure 3 , Figure 4 and Figure 5 Exemplary catheters 300, 400, 500 are shown, respectively. Electrodes or sensors disposed on the distal portion of the catheters 300, 400, 500 can be used to obtain electrical signals measured at the cardiac tissue, which can be used for anatomical and electrical mapping. Another commonly used multi-electrode mapping catheter is As mentioned above, an additional catheter may be used to acquire a reference signal. Such a reference signal may be used to correlate in time, for example, Signals acquired by catheter or balloon catheter 400. Other electrodes or sensors may be used to transmit electrical signals into cardiac tissue, for example, for therapeutic purposes (ablation) and / or to facilitate catheter positioning.

[0035] Figure 3A catheter 300 is shown that includes contact electrodes 332 and non-contact electrodes 338. The non-contact electrodes can measure far-field electrical signals in the ventricles and can be arranged in an array 336 along the longitudinal axis of the distal portion 334 of the catheter 300. The distal portion 334 can also include a position sensor 340 (or multiple position sensors) that can generate or measure signals for determining the position and orientation of the sensor 340. Because there is a fixed spatial relationship between the position sensor 340 and the distal tip 318 and the other electrodes 332, 338, the position of the distal tip 318 and the other electrodes 332, 338 can be determined based on the determined position of the position sensor 340. The handle 320 of the catheter 300 can include a control 346 to guide or deflect the distal portion 334, or orient it as desired.

[0036] For example, the position sensor 340 may be configured to sense an electric field that may be generated by the system 100, 200 (for sensor positioning purposes) and transmit a signal generated from the sensed field via a cable 342 (i.e., Figure 1 The position sensor 340 may transmit signals to the console 124 via a wireless link (see cable 122). In another alternative, the position sensor 340 may transmit signals to the console 124 via a wireless link. Based on the signals sent by the position sensor 340, the processing unit 141, 220 may calculate the position and orientation of the distal portion 334 of the catheter 300 and the position and orientation of the distal tip 318 and other electrodes 332, 338. The position and orientation calculations may be performed based on the signals sent by the position sensor 340 after those signals have been amplified, filtered, digitized, or otherwise processed by the system 100, 200.

[0037] To acquire electrical activity at a certain point in the heart, the catheter 300 can be advanced into the heart and the distal end 318 of the catheter can be brought into contact with the endocardium at a certain tissue location to acquire data at that location. In order to construct an anatomical and electrical map of the heart, this data acquisition process must be repeated for a large number of locations within the region of interest. It may take a long time to construct a detailed map of the region of interest in the heart through this point-by-point data accumulation process. To address this shortcoming, multi-electrode catheters have been developed to simultaneously measure electrical activity at multiple locations in the heart. A catheter such as a balloon catheter (see Figure 4 Description) or annular duct (reference Figure 5 Any suitable shape of the above) can be used to implement a multi-electrode catheter.

[0038] Figure 4 An exemplary balloon catheter 400 is shown, upon which one or more features of the present disclosure may be implemented. Figure 4As shown, the balloon catheter 400 may include a plurality of splines, such as splines 414, 415, and 416. A plurality of electrodes, such as electrodes 421-426, are disposed on each spline. Figure 4 As shown. Balloon catheter 400 can be designed so that when it is deployed into the patient's body, its electrodes can remain in close contact with the endocardial surface. For example, the balloon catheter can be inserted into an inner cavity, such as a pulmonary vein. The balloon catheter can be inserted into the pulmonary vein in a deflated state so that the balloon catheter does not occupy the maximum volume of the pulmonary vein when inserted. The balloon catheter can then be deployed in the pulmonary vein so that the electrodes on the balloon catheter contact the entire circular segment of the pulmonary vein. This contact with the entire circular segment of the pulmonary vein or any other inner cavity can measure electrical activity from multiple points on the tissue. In other words, each acquisition can generate as many activation signals as the number of electrodes.

[0039] Figure 5 An exemplary annular catheter 500 is shown, based on which one or more features of the present disclosure can be implemented. The annular catheter 500 (also referred to as a lasso catheter) can include multiple electrodes 532, 534, 536, which can simultaneously acquire electrical signals measured at the locations of the electrodes when in contact with cardiac tissue (endocardial wall). The annular catheter 500 can be fully or partially elastic, so that the annular catheter can be twisted, bent, or otherwise change its shape based on received signals and / or based on the application of external forces (e.g., when pushed against cardiac tissue).

[0040] Therefore, a multi-electrode catheter such as A catheter, balloon catheter 400, or ring catheter 500) is advanced into a chamber of the heart to acquire electrical (activation) signals. The system 100, 200 can use a position sensor disposed on a multi-electrode catheter (in a known spatial relationship with the electrode) to establish the position of each of the electrodes in the heart. The electrical signals measured by each electrode can be recorded, and these electrical signals can be presented to the physician on a display 127 by the system 100, 200. For example, the measured electrical signals can be presented as vertically aligned electrograms that are temporally correlated according to a reference signal. Typically, the reference signal is measured by a dedicated reference electrode that can be placed, for example, at the CS. Therefore, when using a multi-electrode catheter equipped with many electrodes (each electrode is positioned on the endocardial surface), the physician can collect as many activation signals as the number of electrodes.

[0041] Figure 6 An exemplary method 600 for performing electroanatomical mapping using a multi-electrode mapping catheter 630 and a reference catheter 620 is shown, upon which one or more features of the present disclosure may be implemented. Figure 6In the example shown, catheters 620, 630 are equipped with paired electrodes 620A, 630A, 630B, 630C, each pair being configured to measure bipolar beats. The aspects described herein may also be applicable to the case of using non-paired electrodes, wherein each electrode is configured to measure unipolar beats. As shown, the mapping catheter 630 is placed at a first position 630.1 on the endocardium 610 and then moved to a second position 630.2 on the endocardium. Therefore, the mapping catheter 630 measures the activation signals at those corresponding positions when it is placed at different positions on the endocardium. That is, at each position, a pair of electrodes measures the depolarization of the tissue at that position--the depolarization caused by the electrical signal 605 propagating through the endocardium 610. The electrical signal 605 may originate from the sinoatrial node (e.g., when caused by a normal heartbeat) or may originate from any other position (e.g., when caused by a tachycardia or pacing catheter). The reference catheter 620 is typically used to measure activation at a tissue position near the origin of the electrical signal 605. For example, when the electrical signal 605 originates from the sinoatrial node, the reference catheter 620 may acquire a signal 640 having a normal heartbeat occurring every ˜500 milliseconds (ms).

[0042] In order to construct an electroanatomical map, time measurements associated with activation (or depolarization) of tissue at various locations on the endocardium must be collected and temporally correlated with each other. This is traditionally accomplished by measuring activation signals while moving a mapping catheter along cardiac tissue in one of the chambers of the heart. For example, a first set of activation signals 650.1 may be measured by electrodes of a mapping catheter 630.1 when positioned at a first position, and a second set of activation signals 650.2 may be measured by electrodes of a mapping catheter 630.2 when positioned at a second position. Figure 6 As shown, each group may include activation signals A, B, and C (e.g., belonging to group 650.1) measured by corresponding pairs of electrodes A, B, and C (e.g., acquired at a first position of mapping catheter 630.1). To construct a LAT map, a set of time measurements is derived from the corresponding sets of activation signals. For example, the set of time measurements T A =10ms, T B =12ms and T C = 15 ms is derived from the set 650.1 of activation signals A, B and C respectively. And, the set of time measurements T A =40ms, T B =43ms and T C = 46 ms are derived from the group 650.2 of activation signals A, B and C respectively. As shown, these time measurements are made using the reference time T R =0ms642, 644 are derived relative to the jitter of reference signal 640 (acquired by reference catheter 620). In this way, a set (e.g., 650.1-TA 、650.1-T B and 650.1-T C ) can be combined with the measurements in the second set (e.g., 650.2-T A 、650.2-T B and 650.2-T C ) are combined to form a map that visualizes the propagation of electrical signals across the walls of cardiac structures (e.g., the left ventricle). However, as described above, the need to use a reference catheter 620 complicates the mapping procedure (and is not feasible in some patients). Figures 7 to 9 A method for mapping that does not require the use of a reference catheter 620 is described.

[0043] Figure 7 An exemplary method 700 for electroanatomical mapping using a multi-electrode mapping catheter is shown, based on which one or more features of the present disclosure can be implemented. As shown, electrical signal 705 (equivalent to signal 605) activates endocardium 710. Activation at tissue locations near the origin of electrical signal 705 is shown by activation signal 740. However, unlike reference Figure 6 Compared to the method 600, there is no need to acquire the signal 740 via a reference catheter, such as catheter 620, because according to the method 700, the signal 740 does not need to be used as a reference, as further described below.

[0044] like Figure 7 As shown, during a mapping procedure, the mapping catheter 730 is moved from a first position 730.1 to a second position 730.2 such that there is at least one spatial overlap between the electrodes. Figure 7 In the example of , when the mapping catheter is placed at the second position 730.2, electrode pair A is located at the same position 735 where electrode pair C was located when the catheter was placed at the first position 730.1. Therefore, activation signal C (belonging to group 750.1) and activation signal A (belonging to group 750.2) can be correlated 755. That is, it can be assumed that their corresponding time measurements are the same. Therefore, without using reference signal 740, due to the spatial overlap between electrode pairs (or electrodes when measuring unipolar signals), time measurements from multiple sets can be correlated in time. For example, activation signal A of group 750.1 can be used as reference 752:T A =T R = 0 ms. Other time measurements associated with group 750.1 may be measured relative to this reference, so, as shown, T B =12ms and T C= 15 ms. Next, regarding the time measurement of group 750.2, since activation signal C (belonging to group 750.1) and activation signal A (belonging to group 750.2) are measured by spatially overlapping electrode pairs (electrode pair C of 730.1 and electrode pair A of 730.2, respectively), it is assumed that their time measurements are close enough - i.e., 15 ms. Using this assumption, the time measurement of group 750.2 can be correlated with the time measurement of group 750.1. Therefore, as shown in the figure, the time measurement associated with group 750.2 is T A =15ms, T B =14ms+15ms=29ms, and T C = 18ms + 15ms = 23ms. Note that, as described above, the roles of group 750.1 and group 750.2 can be switched, and any one of the activation signals of the group (750.1 or 750.2) can be used as the reference T R .

[0045] In this manner, time measurements from multiple sets (associated with respective sets of activation signals) may be correlated, or in other words, sets of time measurements (corresponding to different mapping catheter positions on the endocardium) may be combined, as long as each set of activation signals (associated with each set of time measurements) includes at least one activation signal measured by an electrode that overlaps with another electrode measuring an activation signal of another set. Figure 8 Aspects of method 700 are further described.

[0046] Figure 8 An exemplary method 800 for combining a set of measurements acquired by a mapping catheter is shown, upon which one or more features of the present disclosure may be implemented. Figure 8 The concept presented is similar to Figure 7 The concept presented, however, is Figure 8 In the present invention, the positions of electrodes (or pairs of electrodes in the case of bipolar) of a mapping catheter are shown in two-dimensional (2D) space. The same concepts as described herein apply to the positions of electrodes in 3D space, as in practice when using, for example, a multi-electrode mapping catheter (such as Catheter or Figures 4 to 5 The situation when the catheter is shown).

[0047] During a mapping procedure, a physician moves a mapping catheter from one location on the cardiac tissue to another. At each location, the catheter's electrodes acquire an activation signal from which a set of time measurements can be obtained. Thus, each set of time measurements corresponds to each positioning of the mapping catheter during the mapping procedure. Figure 8Four sets of temporal measurements 810, 820, 830, 840 are shown. The first set of measurements 810 is obtained from activation signals measured by electrodes at locations represented by solid circles and acquired when the catheter is placed in a first position. The second set of measurements 820 is obtained from activation signals measured by electrodes at locations represented by hollow circles and acquired when the catheter is placed in a second position. The third set of measurements 830 is obtained from activation signals measured by electrodes at locations represented by diagonal patterned circles and acquired when the catheter is placed in a third position. And, the fourth set of measurements 840 is obtained from activation signals measured by electrodes at locations represented by dashed circles and acquired when the catheter is placed in a fourth position.

[0048] As about Figure 7 As explained in the time measurement sets of the corresponding groups 750.1, 750.2 of FIG. 1 , four sets 810, 820, 830, 840 of time measurements can be combined. For example, these sets can be combined in stages because they are obtained from activation signals acquired by the mapping catheter as it moves along the endocardium. Starting with set 810, for example, the activation signal measured at electrode position 811 can be selected to provide the time reference T R (For example, Figure 7 Reference 750.1-T A 752). Relative to this time reference, time measurements associated with activation signals measured at other electrode locations in set 810 are calculated (e.g., as is calculated Figure 7 Time measurement 750.1-T B and 750.1-T C ). Based on the overlapping electrodes, time measurements associated with activation signals measured at electrode locations of other sets 820-840 are calculated (e.g., as calculated Figure 7 Time measurement of 750.2-T A ,750.2-T B and 750.2-T C ). The combined measurement sets 810-840 may be completed in stages, as shown next.

[0049] In the first stage of mapping procedure 800A, activation signals may be measured by electrodes of a second set 820. A temporal measurement of set 820 may be obtained by combining set 820 with set 810 by utilizing a first spatial overlap 815 that exists between corresponding electrodes of sets 810, 820. Then, in the second stage of mapping procedure 800B, activation signals may be measured by electrodes of a third set 830. This set 830 cannot be combined with any of the previous sets 810, 820 because there is no spatial overlap between any electrode of set 830 and any electrode of the other two sets 810, 820. However, in the third stage of mapping procedure 800C, in which activation signals may be measured by electrodes of a fourth set 840, additional spatial overlap may be introduced. For example, a second spatial overlap 825 between corresponding electrodes from sets 810 and 840, a third spatial overlap 835 between corresponding electrodes from sets 830 and 840, and a fourth spatial overlap 845 between corresponding electrodes from sets 820 and 840. Thus, a temporal measure for set 840 may be obtained by combining the set 810, set 820, or set 830, respectively, using spatial overlap 825, 845, or 835. Furthermore, at this stage 800C, a temporal measure for set 830 may be obtained by combining set 830 with set 840 using a third spatial overlap 835. In this manner, more measurement joints may be combined and a LAT map may be constructed based on the temporal measures for these sets.

[0050] In practice, and as Figure 8 As shown, the spatial overlap 815, 825, 835, 845 between electrodes may not be perfect. That is, the spatial distance between the overlapping electrodes is unlikely to be zero. And, therefore, the time measurements calculated based on those overlaps may be embedded with errors. Such errors may be cumulative because the time measurements of one set depend on the calculation of the time measurements of another set. One way to reduce errors is to consider the degree of overlap. For example, as shown, set 840 includes three overlapping electrodes 825, 835, and 845. Therefore, in one aspect, based on the degree of overlap, based on the degree of overlap, the overlap 825 (denoted as T 825 ), based on overlap 835 (denoted as T 835 ), or based on overlap 845 (denoted as T 845 ) to calculate the time measurement of set 840. In another aspect, the time measurement of set 840 may be calculated based on a weighted combination as follows:

[0051] T(S=840)=ω 825 ·T 825 (S)+ω 835 ·T 835 (S)+ω 845 ·T845 (S), (1)

[0052] where T(S) represents the time measurement of the set S, and the weight ω 825 ,ω 835 ,ω 845 The overlap degree is proportional to the corresponding spatial overlap 825, 835 and 845. The overlap degree can be determined based on the distance between the locations of the overlapping electrodes. For example, a distance below a first threshold (generally, limited by the accuracy of the system to locate the electrodes) can correspond to 100% overlap, while a distance above a second threshold (generally, depending on the spatial distance between the electrodes in the mapping catheter) can result in 0% overlap.

[0053] In one aspect, M versions T of N sets of time measurements may be calculated i＝1-M ={T i (S): S=1-N}. Each version T may be calculated based on different orders of the combined sets (eg, sets 810, 820, 830, and 840). i Alternatively or in combination, the time interval T may be different from the time interval T R (e.g., a reference time associated with electrode 811 or 821) to calculate each version T i Alternatively or in combination, each version T i Different schemes can be used to calculate the i (S), as explained above, for example, with respect to equation (1). Then, the time measurement associated with an electrode at a certain position x can be extracted from all M versions, denoted as {T i (x): i = 1-M}. And, the time measurement T(x) associated with the electrode at position x can be based on {T i For example, T(x) can be predicted based on statistics such as {T i (x): i = 1-M}, the average or median statistics and / or based on The derived statistics are determined, where is the set of electrode locations in a spatial neighborhood centered at x.

[0054] Fig. 9900 is a flowchart of an exemplary method for generating an electroanatomical map of the heart, based on which one or more features of the present disclosure can be implemented. Method 900 begins at step 910, i.e., measuring multiple groups of activation signals. The activation signals of each group can be measured by corresponding electrodes of a mapping catheter placed at corresponding locations in the heart. The mapping catheter can be placed in a position within the heart so that one or more electrodes measuring the activation signals of one group spatially overlap with corresponding electrodes measuring the activation signals of other groups. In one aspect, if the distance between the electrodes is below a predetermined threshold, the electrodes are determined to overlap. In step 920, based on the measured activation signal groups, the overlapping electrodes can be used to obtain a set of corresponding time measurement values, as described above with reference to Figure 7 and Figure 8 In step 930, an electroanatomical map may be constructed based on the obtained set of temporal measurements. Further aspects of method 900 are described below.

[0055] In a first aspect, obtaining a first set of time measurements (of a set of time measurements) may be based on an activation signal of a corresponding first group (of a signal activation group), wherein the time measurements are calculated relative to a time reference provided by a first activation signal of the first group (e.g., may be based on a time reference 750.1-T provided by activation signal 750.1-A). A 752 Computed Time Measurement 750.1-T B ).

[0056] In a second aspect, obtaining a time measurement of a second set (of the set of time measurements) may be based on an activation signal of a corresponding second set (of the signal activation set), wherein the time measurement is calculated relative to another time measurement obtained based on the activation signal of the other set, and wherein the activation signal of the other set is measured by a first electrode overlapping with a second electrode measuring the activation signal of the second set (e.g., such as relative to time measurement 750.1-T obtained based on activation signal 750.2-C). C To calculate the time measurement 750.2-T B , where activation signal 750.1-C is measured by electrode 730.2-C that overlaps electrode 730.1-A measuring activation signal 750.1-A). Note that in the second aspect, the time measurement can be adjusted based on the degree of overlap between the first electrode and the second electrode. Furthermore, a certainty metric can be associated with the time measurement based on such degree of overlap.

[0057] Thus, a deterministic metric can be calculated for the corresponding time measurements. In one aspect, the deterministic metric can be calculated based on the shape of the corresponding activation signal. For example, the deterministic metric of the corresponding time measurements associated with the electrode positions within a small neighborhood can be determined based on the morphological similarity of the unipolar electrical signals measured by those electrodes. Thus, when constructing an electroanatomical map, the time measurements can be filtered based on their corresponding deterministic metric.

[0058] Although features and elements are specifically described above, those skilled in the art will appreciate that each feature or element may be used alone or in any combination with other features and elements. In addition, although process steps are described above in a particular order, these steps may be performed in other desired orders.

[0059] The methods, processes, modules and systems described herein may 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 a wired or wireless connection) 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 may be used to implement a radio frequency transceiver used in a WTRU, UE, terminal, base station, RNC, or any host computer.

[0060] Additional embodiments herein may be constructed by supplementing an embodiment with one or more elements from any one or more other embodiments herein, and / or replacing one or more elements in one embodiment with one or more elements from one or more other embodiments herein.

[0061] It is understood, therefore, that the disclosed subject matter is not limited to the particular embodiments disclosed, but is intended to cover all modifications consistent with the spirit and scope of the present disclosure as defined by the appended claims, detailed description, and / or as shown in the accompanying drawings.

Claims

1. A method for generating an electroanatomical map of a heart, the method comprising: measuring a plurality of sets of activation signals, the activation signals in each set of activation signals being measured by corresponding electrodes of a mapping catheter placed at corresponding locations in the heart, wherein at least one electrode of the mapping catheter that measures an activation signal of one group of activation signals among the multiple groups of activation signals overlaps spatially with a corresponding electrode of the mapping catheter that measures an activation signal of another group of activation signals among the multiple groups of activation signals; Based on the multiple sets of activation signals, obtaining corresponding sets of time measurements using overlapping electrodes; and The electroanatomical map is constructed based on the obtained set of temporal measurements.

2. The method according to claim 1, wherein: In case that the distance between the at least one electrode and the corresponding electrode is lower than a predetermined threshold, the at least one electrode and the corresponding electrode overlap.

3. The method according to claim 1, wherein: The obtaining further comprises: A time measurement of a first one of the sets is calculated based on activation signals of a corresponding first one of the plurality of sets of activation signals, wherein the time measurement is calculated relative to a time reference provided by a first one of the first set of activation signals.

4. The method according to claim 3, wherein: The obtaining further comprises: A time measurement of a second set in the set is calculated based on activation signals of a corresponding second set of activation signals in the multiple sets of activation signals, wherein the time measurement is calculated relative to another time measurement obtained based on activation signals in another set of activation signals, wherein the activation signals in the other set of activation signals have been measured by a first electrode overlapping with a second electrode at which the activation signals in the second set of activation signals were measured.

5. The method according to claim 4, wherein: Calculating the time measurements of the second set further comprises: The time measurements of the second set are adjusted based on a degree of overlap between the first electrode and the second electrode.

6. The method according to claim 4, wherein: The obtaining further comprises: A certainty metric is calculated for each time measurement in the set of time measurements.

7. The method according to claim 6, wherein: A certainty metric associated with the time measurements of the second set is calculated based on a degree of overlap between the first electrode and the second electrode.

8. The method according to claim 6, wherein: A certainty metric associated with the time measurement is calculated based on the shape of the activation signal measured by the corresponding electrode.

9. The method according to claim 6, wherein: Constructing the electroanatomical map further comprises: The respective time measurements in the set of time measurements are filtered based on the certainty metric.

10. The method according to claim 4, wherein: The obtaining further comprises: calculating a plurality of versions of the respective sets of the time measurements, wherein, for each version, when calculating the second set of time measurements, the another set of activation signals is a different set of activation signals in the plurality of sets of activation signals; and The set of time measurements is predicted based on the plurality of versions.

11. The method according to claim 3, wherein: The obtaining further comprises: computing a plurality of versions of the respective sets of the time measurements, wherein, for each version, another one of the sets is selected as the first set; and The set of time measurements is predicted based on the plurality of versions.

12. The method according to claim 3, wherein: The obtaining further comprises: calculating a time measurement of a second set of the sets based on activation signals of a corresponding second set of activation signals of the plurality of sets of activation signals, the time measurement being calculated based on a weighted combination of time elements, wherein each time element is calculated relative to a time measurement calculated based on an activation signal in another set of activation signals, wherein the activation signal in the other set of activation signals has been measured by a first electrode that overlaps with a second electrode that measured the activation signal in the second set of activation signals, and the weight associated with the time element is calculated based on the degree of overlap between the first electrode and the second electrode.

13. A system for generating an electroanatomical map of a heart, the system comprising: at least one processor; and a memory storing instructions that, when executed by the at least one processor, cause the system to: measuring a plurality of sets of activation signals, the activation signals in each set of activation signals being measured by corresponding electrodes of a mapping catheter placed at corresponding locations in the heart, wherein at least one electrode of the mapping catheter that measures an activation signal of one group of activation signals among the multiple groups of activation signals overlaps spatially with a corresponding electrode of the mapping catheter that measures an activation signal of another group of activation signals among the multiple groups of activation signals, Based on the plurality of sets of activation signals, obtaining corresponding sets of time measurements using overlapping electrodes, and The electroanatomical map is constructed based on the obtained set of temporal measurements.

14. The system according to claim 11, wherein: In case that the distance between the at least one electrode and the corresponding electrode is lower than a predetermined threshold, the at least one electrode and the corresponding electrode overlap.

15. The system according to claim 11, wherein: The obtaining further comprises: A time measurement of a first one of the sets is calculated based on activation signals of a corresponding first one of the plurality of sets of activation signals, wherein the time measurement is calculated relative to a time reference provided by a first one of the first set of activation signals.

16. The system of claim 13, wherein: The obtaining further comprises: A time measurement of a second set in the set is calculated based on activation signals of a corresponding second set of activation signals in the multiple sets of activation signals, wherein the time measurement is calculated relative to another time measurement obtained based on activation signals in another set of activation signals, wherein the activation signals in the other set of activation signals have been measured by a first electrode overlapping with a second electrode at which the activation signals in the second set of activation signals were measured.

17. The system of claim 14, wherein: Calculating the time measurements of the second set further comprises: The time measurements of the second set are adjusted based on a degree of overlap between the first electrode and the second electrode.

18. The system of claim 14, wherein: The obtaining further comprises: A certainty metric is calculated for each time measurement in the set of time measurements, wherein the certainty metric associated with the time measurement of the second set is calculated based on a degree of overlap between the first electrode and the second electrode.

19. The system of claim 16, wherein: Constructing the electroanatomical map further comprises: The respective time measurements in the set of time measurements are filtered based on the certainty metric.

20. The system of claim 14, wherein: The obtaining further comprises: computing multiple versions of the corresponding sets of the time measurements; and The set of time measurements is predicted based on the plurality of versions, wherein: For each version, when calculating the time measurement of the second set, the another set of activation signals is a different set of activation signals from the plurality of sets of activation signals, or For each version, another one of the sets is selected as the first set.

21. The system of claim 13, wherein: The obtaining further comprises: calculating a time measurement of a second set of the sets based on activation signals of a corresponding second set of activation signals of the plurality of sets of activation signals, the time measurement being calculated based on a weighted combination of time elements, wherein each time element is calculated relative to a time measurement calculated based on an activation signal in another set of activation signals, wherein the activation signal in the other set of activation signals has been measured by a first electrode that overlaps with a second electrode that measured the activation signal in the second set of activation signals, and the weight associated with the time element is calculated based on the degree of overlap between the first electrode and the second electrode.

22. A non-transitory computer readable medium comprising instructions executable by at least one processor to perform a method for generating an electroanatomical map of a heart, the method comprising: measuring a plurality of sets of activation signals, the activation signals in each set of activation signals being measured by corresponding electrodes of a mapping catheter placed at corresponding positions in the heart, wherein at least one electrode of the mapping catheter that measures an activation signal of one group of activation signals among the multiple groups of activation signals overlaps spatially with a corresponding electrode of the mapping catheter that measures an activation signal of another group of activation signals among the multiple groups of activation signals; Based on the multiple sets of activation signals, obtaining corresponding sets of time measurements using overlapping electrodes; and The electroanatomical map is constructed based on the obtained set of temporal measurements.

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