Automatic storage and display of ECG signals indicative of atrial fibrillation

Abstract

A method includes inserting a catheter having a plurality of electrodes into a heart of a patient and placing the electrodes in contact with tissue of the heart. For each of the electrodes: (i) a position signal indicative of a position of the electrode and (ii) an electrocardiogram (ECG) signal acquired by the electrode are received during a predefined time interval. A positioning stability along the predefined time interval is calculated for each of the electrodes based on the position signal. For the electrode whose positioning stability has an error less than a given threshold, it is calculated whether the ECG signal is indicative of atrial fibrillation (AF) in the heart. The ECG signal indicative of the AF is stored.

Description

Technical Field

[0001] The present disclosure relates generally to medical devices, and in particular to methods and systems for automatically storing ECG signals indicative of atrial fibrillation. Background Art

[0002] Various techniques have been published for determining cardiac arrhythmias, such as atrial fibrillation.

[0003] For example, U.S. Pat. No. 10,939,863 describes a method that includes receiving in a processor a two-dimensional (2D) electroanatomical (EA) map of an inner surface of at least a portion of a cavity of an organ of a patient, the 2D EA map including electrophysiological (EP) values ​​measured at corresponding locations on the inner surface. Fitting a complex analytical function to a set of EP values ​​measured in a given region of the 2D EA map. Identifying singularities in the fitted complex analytical function. Projecting the region onto a three-dimensional (3D) EA map of the inner surface. Presenting at least a portion of the 3D EA map to a user, including indicating arrhythmogenic EP activity at a location on the 3D EA map corresponding to the singularity identified in the fitted complex analytical function. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] 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:

[0005] Figure 1 is a schematic illustration of a catheter-based localization-tracking and ablation system according to an example of the present disclosure;

[0006] Figure 2 is a schematic illustration of a segment of a heart and an electrocardiogram (ECG) signal sensed in the segment and indicating atrial fibrillation (AF) in the heart according to an example of the present disclosure; and

[0007] Figure 3 is a flow chart schematically illustrating a method for automatically storing and presenting ECG signals indicative of AF according to an example of the present disclosure. DETAILED DESCRIPTION

[0008] Overview

[0009] Examples of the present disclosure described below provide improved techniques for storing and presenting electrocardiogram (ECG) signals indicative of atrial fibrillation in a patient's heart.

[0010] In some examples, the system includes a catheter having a distal end assembly (DEA) that includes a plurality of (e.g., about 48) electrodes arranged in an array for covering a segment in the heart. The system also includes a patch electrode attached to the patient's chest skin, and a magnetic-based position sensor configured to generate a position signal indicating the position of the DEA in the patient's heart (in a predefined coordinate system). When placed in contact with cardiac tissue, each of the electrodes is configured to generate an impedance-based position signal indicating the position of the corresponding electrode in a predefined coordinate system. It should be noted that the impedance-based position signal is generated based on an impedance measurement between (i) each of the electrodes of the DEA and (ii) one or more of the patch electrodes.

[0011] In some examples, when placed in contact with tissue, each of the electrodes of the DEA is configured to produce an electrocardiogram (ECG) signal that is sensed in the tissue.

[0012] In some examples, the system includes a processor configured to receive, during a predefined time interval, for each electrode of a catheter placed in contact with tissue: (i) a position signal indicating the position of the electrode, and (ii) an ECG signal acquired by each of the electrodes, as described above.

[0013] In some examples, the processor is configured to calculate the positioning stability along the predefined time interval for each of the electrodes based on the position signal. Figure 1 The advanced catheter localization (ACL) catheter position tracking method described in detail in the present invention calculates positioning stability. In this example, an impedance-based position signal is used in the ACL, and the standard deviation (SD) of the impedance-based position signal is calculated along a predefined time interval, for example, the duration of the time interval can be about 2.5 seconds. The processor is configured to maintain a threshold indicating the positioning stability of each electrode of the DEA. For example, the threshold may have a value of about 3 mm, so that an electrode of the DEA whose position signal has an SD of less than about 3 mm is referred to as a qualified electrode in this article, and an electrode of the DEA whose position signal has an SD of greater than about 3 mm is referred to as an unsuitable electrode in this article.

[0014] In some examples, the processor is configured to receive ECG signals sensed and acquired by electrodes of the DEA during predefined time intervals.

[0015] In some examples, the processor is configured to calculate, for qualified electrodes (i.e., electrodes having an error (e.g., SD) for their positioning stability that is less than a given threshold (e.g., 3 mm)), whether the ECG signal indicates atrial fibrillation (AF) in the heart.

[0016] In some examples, the system includes a memory, and the processor is configured to control the memory to automatically store ECG signals that have been identified as indicating AF.It should be noted that the ECG signal may indicate different attributes indicative of AF.

[0017] In some examples, the system includes a display, and the processor is configured to control the display to display the stored ECG signals on one or more maps of the heart. The stored ECG signals may be displayed on a single map such that ECG signals indicating a first attribute of the indicated AF are labeled with a first label, and ECG signals indicating a second attribute (different from the first attribute) of the indicated AF are labeled with a second label different from the first label. In an alternative example, the processor is configured to display on the display: (i) a first map of at least one segment of the heart having an ECG signal indicating the first attribute, and (ii) a second map of at least one segment of the heart having an ECG signal indicating the second attribute. In other words, the ECG signals may be presented on different maps of the heart.

[0018] The disclosed technology improves the quality of electrophysiological (EP) mapping by eliminating ECG signals acquired by electrodes whose positioning stability is insufficient. In addition, the disclosed technology reduces the duration of EP mapping procedures by: (i) using a multi-electrode catheter that covers the segment in the tissue in question and using the electrodes of the catheter to simultaneously acquire position signals and ECG signals, and (ii) automatically storing ECG signals indicative of atrial fibrillation in the heart and displaying the corresponding ECG signals on one or more maps of the heart.

[0019] System Description

[0020] Figure 1 is a schematic illustration of a catheter-based localization-tracking and ablation system 20 according to an example of the present disclosure.

[0021] In some examples, system 20 includes a catheter 22 (in this example, a multi-strip and multi-electrode cardiac catheter described below) and a console 24. In the examples described herein, catheter 22 may be used for any suitable therapeutic and / or diagnostic purposes, such as, but not limited to, sensing electroanatomical (EA) information in the tissue in question and applying ablation signals to tissue of heart 26. In the context of the present disclosure, the term "information" refers to the spatial position of each electrode at the distal end of the catheter and the electrocardiogram (ECG) signal sensed by the corresponding electrode of catheter 22.

[0022] In some examples, the console 24 includes a processor 42 (typically a general purpose computer) having a suitable front end and interface circuitry for receiving signals from the catheter 22 and for controlling other components of the system 20 described herein. The processor 42 can be programmed in software to perform the functions used by the system and is configured to store data for the software in a memory 50. For example, the software can be downloaded to the console 24 in electronic form over a network, or the software can be provided on a non-transitory tangible medium such as an optical, magnetic or electronic memory medium. Alternatively, an application specific integrated circuit (ASIC) or any suitable type of programmable digital hardware component can be used to perform some or all of the functions of the processor 42.

[0023] Reference is now made to Illustration 25. In some examples, catheter 22 includes a distal tip assembly (DEA) 40 having a plurality (eg, six) strips, each of which includes a plurality (eg, eight) electrodes configured to sense signals from tissue of heart 26.

[0024] Reference is now made to illustration 48 which shows a DEA 40. In this example, the DEA 40 comprises a Picasso manufactured by Biosense Webster Inc. (Irvine, Calif.). TM Catheter. Picasso TM The catheter includes six strips 54 arranged at a distance 70 relative to each other so as to cover a surface in the tissue of the heart 26. It should be noted that the strips 54 are flexible to conform to the tissue in question. Each strip 54 has eight electrodes 55, which, when placed in contact with the tissue of the heart 26, are configured to generate signals indicating the following: (i) an electrocardiogram (ECG) signal in the corresponding tissue, and (ii) an impedance indicating the position of each electrode in the XYZ coordinate system of the system 20, as will be described in detail below.

[0025] In this example, the electrodes 55 are positioned at a distance 72 from each other. The ECG signal and the sensed impedance may include a unipolar signal or a bipolar signal, as will be described below. In other examples, the DEA 40 may include any other suitable type of DEA having a plurality of electrodes arranged in an array covering a suitable area of ​​tissue of the heart 26.

[0026] Now return to reference Figure 1. In some examples, catheter 22 includes a shaft 23 for inserting DEA 40 into a target location for ablating tissue in heart 26. During an electrophysiological (EP) mapping and / or ablation procedure, a physician 30 inserts catheter 22 through the vasculature of a patient 28 lying on an operating table 29. The physician 30 moves DEA 40 to a target location in heart 26 using a manipulator 32 near the proximal end of catheter 22, which is connected to an interface circuit of a processor 42. In this example, the target location may include tissue having one or more sites intended to be diagnosed (and optionally ablated) by DEA 40.

[0027] In some examples, system 20 includes external patch electrodes 49 that are coupled to the skin of the chest of patient 28 and are configured to sense signals indicative of ECG and / or impedance.

[0028] In some examples, based on the signals received from the electrodes 55 (of the DEA 40) and the external patch electrodes 49, the processor 42 is configured to generate a position signal indicating the position of each electrode 55 in the XYZ coordinate system of the heart 26. The position signal is generated using the Advanced Catheter Localization (ACL) catheter position tracking method described below. In this example, the processor 42 is connected to the patch electrodes 49 using wires extending through the cable 37.

[0029] In some examples, processor 42 is configured to determine the position coordinates of each electrode 55 based on the impedance measured between each electrode 55 and each of patch electrodes 49. The ACL method of electrode position sensing using system 20 is implemented in various medical applications, such as in the CARTO TM The invention is implemented in the system and is described in detail in U.S. Patent Nos. 7,756,576, 7,869,865 and 7,848,787.

[0030] Reference is now made back to illustration 48. In some examples, catheter 22 includes a position sensor 39 of a magnetic-based position tracking system coupled to a distal end of catheter 22, e.g., proximate DEA 40. In this example, position sensor 39 includes a magnetic position sensor, but in other examples, any other suitable type of position sensor (e.g., other than magnetic-based) may be used.

[0031] Now return to reference Figure 1In some examples, during navigation of DEA 40 in heart 26, processor 42 receives signals from magnetic position sensor 39 in response to a magnetic field from external field generator 36, e.g., for measuring the position of DEA 40 in heart 26. In some examples, console 24 includes drive circuit 34 configured to drive magnetic field generator 36. Magnetic field generator 36 is placed at a known location external to patient 28, e.g., below table 29.

[0032] In some examples, processor 42 is configured to display the tracked position of DEA 40 superimposed on an image 44 of heart 26 , which is typically a three-dimensional (3D) image, for example, on a display 46 of console 24 .

[0033] Position sensing methods using external magnetic fields are implemented in various medical applications, for example, in the CARTO TM The system is implemented in the present invention and is described in detail in U.S. Patent Nos. 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612 and 6,332,089, PCT Patent Publication No. WO 96 / 05768, and U.S. Patent Application Publication Nos. 2002 / 0065455 Al, 2003 / 0120150 Al and 2004 / 0068178 Al.

[0034] In some examples, processor 42 is configured to use the magnetic-based and ACL-based position signals to calculate, for example, a roll angle of DEA 40 in order to correct the ACL-based position of one or more electrodes 55. Furthermore, based on the magnetic-based position signal, processor 42 is configured to adjust the orientation of (the flat array of) DEA 40 relative to the tissue in question of heart 26.

[0035] One specific implementation of using a combination of magnetic-based position tracking systems to improve the position sensing performance of an ACL system is described in U.S. Patent Application Publication 2019 / 0021789, whose inventors are Gliner et al. and which is assigned to the applicant of the present disclosure.

[0036] In some examples, the ECG signal may include: (i) a bipolar ECG signal sensed between two electrodes 55 (or between two groups of electrodes 55 or using any other suitable polarity (using a suitable arrangement of electrodes 55)), or (ii) a unipolar signal sensed between each electrode 55 and one or more of the patch electrodes 49.

[0037] This particular configuration of system 20 is shown by way of example in order to illustrate certain problems solved by the examples of the present disclosure and to demonstrate the application of these examples in enhancing the performance of such systems. However, the examples of the present disclosure are by no means limited to this particular class of exemplary systems, and the principles described herein may be similarly applied to other classes of medical systems.

[0038] Automatically stores and displays ECG signals indicative of atrial fibrillation

[0039] Figure 2 is a heart 26 ( Figure 1 ) and an electrocardiogram (ECG) signal sensed by electrodes 55 of DEA 40 in segment 27 and indicating atrial fibrillation (AF) in heart 26.

[0040] In some examples, as described above in Figure 1 As described in the foregoing, physician 30 moves DEA 40 to the tissue in question, in this example, to segment 27 located on the inner wall of the atrium of heart 26. In some examples, strip 54 is placed on segment 27 so that at least some and typically all 48 electrodes 55 are placed in contact with the tissue of segment 27.

[0041] In some examples, processor 42 is configured to receive a plurality of position signals from each of position sensor 39 and the ACL position tracking system during a predefined time interval (e.g., between about 1 second and 10 seconds), as described above in Figure 1 . In this example, the time interval may include about 2.5 seconds, and during the time interval, the processor 42 may receive about 150 position signal sets (i.e., about every 16.7 milliseconds). Based on the about 150 position signal sets received during the time interval, the processor 42 is configured to estimate the position of each electrode 55 (and DEA 40) along the time interval. In addition, the processor 42 is configured to calculate the average position and the standard deviation (SD) of the position for each electrode 55 along the 2.5 second time interval.

[0042] In some examples, processor 42 is configured to maintain a threshold value indicating the position stability along the time interval for each electrode 55. In the context of the present disclosure and in the claims, the term "position stability along the time interval" refers to the deviation of the calculated position of a given electrode 55 relative to an average position of the given electrode 55, which is calculated based on the position signals received during a predefined time interval (e.g., 2.5 seconds).

[0043] In the present example, the threshold has a value of about 3 mm, such that in the case where the SD of the position along the 2.5 second time interval is less than 3, the ECG signal received from a given electrode 55 can be used to detect whether the sensed ECG signal indicates AF in the heart 26. Such ECG signals are also referred to herein as qualified ECG signals. In the case where the SD is greater than about 3 mm, the ECG signal received from a given electrode 55 cannot be used to detect whether the ECG signal sensed by the given electrode 55 indicates AF in the heart 26. Such ECG signals are also referred to herein as unqualified ECG signals.

[0044] In some examples, upon identifying an insufficient number of electrodes (e.g., less than 3 electrodes) whose SD is less than 3 mm, physician 30 defines a new time interval (having the same duration of approximately 2.5 seconds, or a different duration) for repeatedly collecting position signals and ECG signals from tissue in segment 27 of heart 26.

[0045] In the context of the present disclosure and in the claims, the terms "about" or "approximately" for any numerical value or range of values ​​indicate suitable dimensional tolerances that allow: (i) a portion or collection of components and (ii) a measurable abstract feature (such as the aforementioned time intervals and measurements associated with ECG and position signals) to function for the intended purposes described herein.

[0046] In some examples, after obtaining ECG measurements from a sufficient number (e.g., 3 or more) of electrodes 55, processor 42 is configured to calculate several features and / or attributes and / or parameters that indicate whether the ECG signal indicates AF in heart 26. It should be noted that ECG signals sensed by electrodes 55 whose SD is greater than 3 do not qualify as providing an indication of AF, and therefore, processor 42 is configured to filter these ECG signals out of the calculation of the above-mentioned features and / or attributes and / or parameters.

[0047] In the context of the present disclosure and in the claims, the terms “feature,” “attribute,” “parameter,” and “criteria,” and grammatical variations thereof, are used interchangeably and refer to an indication of whether the above-mentioned ECG signal indicates AF in the heart 26 .

[0048] It should be noted that atrial fibrillation causes the calculated parameters to change over time. Therefore, it is important to select parameters that are indicative of AF. For example, the atrial fibrillation cycle length (AFCL) may indicate AF in the heart 26. In the present example, an AFLC having a value between approximately 120 and 200 milliseconds (ms) indicates a healthy area in the heart 26, while an AFCL value less than approximately 120 ms or greater than approximately 200 ms indicates a problem that may be associated with AF in the heart 26. More specifically, a gradient of AFCL values ​​along different locations along the atrial tissue may be used to map AF in the corresponding atrium. For example, such techniques are described in U.S. patent application serial number 11,160,481 assigned to the present applicant. It should be noted that insufficient positioning stability (e.g., having an SD greater than approximately 3 mm) of one or more electrodes used to sense ECG signals may result in insufficient accuracy of the calculated AFCL values ​​and gradients.

[0049] In some examples, processor 42 is configured to apply various types of filters to ECG signals received from electrodes 55 having an SD less than 3 mm in order to calculate whether qualified ECG signals are indicative of AF in heart 26. In some examples, in response to identifying qualified ECG signals for calculating parameters indicative of AF, processor 42 is configured to automatically store these ECG signals, for example, in memory 50 of console 24.

[0050] In some examples, based on the stored ECG signals, processor 42 is configured to identify an indication of AF in region 27 of heart 26. Figure 2 In the example of , processor 42 is configured to display a conduction velocity vector 66 on a 3D anatomical map of segment 27 , the conduction velocity vector indicating, for example, a propagation direction and speed of an electrophysiological (EP) signal on the surface of tissue of segment 27 .

[0051] In some examples, processor 42 is configured to identify a mode indicative of AF. Figure 2 In an example of FIG. 4 , processor 42 is configured to identify, within segment 27, a segment 77 having a focus 61 in the tissue of heart 26. Reference is now made to illustration 63. In some examples, conduction velocity vectors 66 are arranged as if they radiate from focus 61. More specifically, focus 61 is a virtual point or area that is the origin of vectors 66, as shown in illustration 63. In such examples, processor 42 may apply various pattern recognition techniques for identifying focus 61 in segment 77.

[0052] Now return to reference Figure 2 In some examples, if three points within a sub-segment of segment 27 have a gradient of AFCL values, the sub-segment may indicate AF. Figure 2In the example of , based on the qualified ECG signal, processor 42 has calculated AFCL values ​​at approximately 150 ms, 200 ms, and 270 ms at points 74, 75, and 76, respectively, along line 73. This gradient of AFCL values ​​indicates potential AF, and therefore, processor 42 is configured to identify and store the ECG signals measured by electrode 55 in the corresponding sub-segment proximate to line 73. In addition, processor 42 is configured to display line 73 or any other indication of the AFCL gradient on the map of segment 27.

[0053] Reference is now made to sub-segment 64 of the map of segment 27. In some examples, some electrodes 55 are positioned within the region of sub-segment 64, more specifically, electrodes 55a, 55b, 55c, and 55d are among these electrodes.

[0054] Referring now to inset 67, a set of graphs 65 are shown which present the distribution of sequential activations of continuous bipolar ECG signals produced by electrodes 55 located within sub-segment 64. For example, graphs 88a, 88b, 88c, and 88d are produced by electrodes 55a, 55b, 55c, and 55d, respectively. The amplitude of the bipolar signal is presented along axis 51, and the amplitude of the signal over time is presented along axis 53. In addition, the time intervals of the graphs span 100% of the length of the atrial fibrillation cycle described above.

[0055] In this example, the set of graphs 65 includes vertical marks 57 and 59. As shown in inset 67, the peaks (e.g., R peaks) indicating activation in the corresponding ECG signals are positioned with an offset relative to each other along axis 53. For example, the peak of graph 88a falls on mark 59, while the positions of the peaks of graphs 88b, 88c, and 88d are shifted, and thus the peaks do not fall on mark 59. In another example, the peaks of graphs 88b and 88c are before the time point of mark 57, and the peaks of graphs 88a and 88d are after the time point of mark 57. This distribution of sequential activations of continuous bipolar ECG signals can indicate an AF source.

[0056] In other examples, processor 42 is configured to identify other parameters and / or features and / or attributes indicative of AF, eg, using any suitable calculation or manipulation of qualified ECG signals, as described above.

[0057] Figure 3 is a flow chart schematically illustrating a method for automatically storing and presenting ECG signals indicative of AF in heart 26 according to an example of the present disclosure.

[0058] The method begins with a catheter insertion step 100, in which the physician 30 inserts a DEA 40 (of the catheter 22) having a plurality (eg, 48) of electrodes 55, as described above. Figure 1In the position stability check step 102, the physician 30 places the electrode 55 in contact with the tissue in question of the region 27 in the heart 26. In some examples, the processor 42 receives during a predefined time interval of, for example, about 2.5 seconds: (i) position signals from the electrode 55 and the patch electrode 49, and (ii) ECG signals from the electrode 55. In addition, based on the received position signals, the processor 42 checks the position stability of each electrode 55, as described above in Figure 1 and Figure 2 Described in detail in .

[0059] At a first decision step 104, processor 42 makes a comparison between: (i) a threshold value having a predefined value (e.g., approximately 3 mm), and (ii) the calculated SD of the position signals received along the time interval for each electrode 55, as described above in Figure 2 In the case where the calculated SD is greater than the threshold, the method loops back to step 102.

[0060] In some examples, the processor 42 also defines a minimum number of qualified electrodes 55 (i.e., electrodes 55 whose positioning stability has an error (i.e., SD) less than a threshold value). In the event that the number of qualified electrodes 55 is less than the minimum number, the method loops back to step 102. For example, in the event that only one or two electrodes 55 (e.g., out of the 48 electrodes of the DEA 40) have a calculated SD less than about 3 mm, the method loops back to step 102.

[0061] In the event that the calculated SD of the position signal of a given electrode 55 is less than the 3 mm threshold, the given electrode 55 is qualified and the ECG signal produced by the given electrode 55 during the same 2.5 second time interval will be used by the processor 42 in subsequent steps of the method.

[0062] In some examples, in the event that the number of qualified electrodes is greater than a minimum number defined in processor 42, the method proceeds to a second decision step 106. It should be noted that in step 106, only the ECG signals of the qualified electrodes are used. In step 106, processor 42 is configured to calculate whether the ECG signals generated by qualified electrodes 55 during the time interval indicate atrial fibrillation (AF) in heart 26. In other words, processor 42 is configured to check whether the criteria indicating AF are met based on the ECG signals generated by qualified electrodes 55 during the time interval. For example, processor 42 may apply various pattern recognition techniques for identifying focal point 61 in segment 77, as described above in Figure 2 Described in .

[0063] In the event that the processor 42 identifies that the ECG signal of step 106 above indicates AF, the method proceeds to the automatic storage step 108. In step 108 ending the method, the processor 42 automatically stores in the memory 50 the ECG signal used to calculate the parameters indicating AF, as described above in Figure 2 In some examples, processor 42 is configured to visualize criteria indicative of AF on a suitable anatomical or electroanatomical map of heart 26. The visualized criteria are based on calculations of ECG signals indicative of AF in heart 26, as described above in Figure 2 Described in .

[0064] In some examples, where processor 42 does not identify that the ECG signal of step 106 above indicates AF, the method loops back to step 102, and physician 30 moves DEA 40 to cover another segment of heart 26 other than segment 27. It should be noted that in the other segment, processor 42 and / or physician 30 may select the duration of the time interval to be similar to the time interval selected when electrodes 55 of DEA 40 are placed in contact with segment 27, e.g., 2.5 seconds. In alternative examples, processor 42 and / or physician 30 may select different durations of time intervals for sensing position signals and ECG signals in another segment.

[0065] In some examples, the disclosed techniques provide the physician 30 with automatic storage of ECG signals that: (i) are obtained with stable positioning of the corresponding electrodes 55, (ii) are obtained during a short time interval (e.g., about 2.5 seconds) in a relatively large segment (e.g., segment 27) of the heart 26 covered by the DEA 40, and (iii) are indicative of AF in the heart 26. In principle, the ECG signal can be acquired by visiting point by point in segment 27, but this process can significantly prolong the procedure, and the points are not acquired at the same time interval, so it is not as convenient as using the above method. Figure 2 The techniques and Figure 3 Compared with the methods to obtain the results, the results may not be indicative of AF.

[0066] In other examples, ECG mapping ends when (i) physician 30 decides to acquire ECG signals only in segment 27, or (ii) steps 102-108 are repeated in additional segments in heart 26. In such examples, processor 42 presents the stored ECG signals indicative of AF on one or more maps of heart 26.

[0067] In some examples, at least one of the stored ECG signals may be displayed in a separate map.For example, processor 42 may generate a map of heart 26 with focal points 61 identified at one or more sections of heart 26.

[0068] In other examples, processor 42 may display all ECG signals indicative of AF in a single map of heart 26 and automatically stored in memory 50, as described, for example, above. Figure 2 27 of the segment 27. In such an example, processor 42 is configured to add different labels to the ECG signal included in the different attributes of AF. For example, (i) a segment 77 indicating focus 61 and (ii) a line 73 indicating the AFCL gradient along points 74-76 are shown on the map of segment 27 using different graphical representations and / or markings, as described above in Figure 2 As shown and described in.

[0069] Figure 3 The method is simplified and provided by way of example for conceptual clarity. In other examples, Figure 3 Additional or alternative steps may be included, for example, according to the above Figures 1 to 3 The techniques disclosed in the present invention use different specific implementations or orders of steps.

[0070] The examples described herein are primarily directed to automatically storing and presenting ECG signals indicative of atrial fibrillation in the heart. The methods and systems described herein may also be used in other applications, such as for procedures related to other kinds of arrhythmias, such as but not limited to the sensing and / or treatment of ventricular tachycardia (VT) and Brugada syndrome.

[0071] Example 1

[0072] A method comprising:

[0073] (i) inserting a catheter (22) having a plurality of electrodes (55) into the heart (26) of a patient (28)

[0074] and placing the electrodes (55, 55a, 55b, 55c, 55d) in contact with tissue of the heart (26);

[0075] (ii) receiving, for each of the electrodes (55, 55a, 55b, 55c, 55d) during a predefined time interval: (i) a position signal indicating the position of the electrode (55, 55a, 55b, 55c, 55d), and (ii) an electrocardiogram (ECG) signal acquired by the electrode (55, 55a, 55b, 55c, 55d);

[0076] (iii) calculating, for each of the electrodes (55, 55a, 55b, 55c, 55d) a positioning stability along the predefined time interval based on the position signal;

[0077] (iv) calculating, for the electrodes (55, 55a, 55b, 55c, 55d) whose positioning stability has an error less than a given threshold, whether the ECG signal indicates atrial fibrillation (AF) in the heart (26); and

[0078] (v) storing the ECG signal indicative of the AF.

[0079] Example 2

[0080] A method according to embodiment 1, wherein storing the ECG signals indicating the AF includes storing: (i) a first set of the ECG signals calculated with a first attribute indicating the AF, and (ii) a second set of the ECG signals different from the first set calculated with a second attribute indicating the AF, wherein the second attribute is different from the first attribute.

[0081] Example 3

[0082] The method according to Example 2, wherein the method further comprises displaying the stored ECG signals on one or more maps of the heart.

[0083] Example 4

[0084] A method according to Example 3, wherein displaying the stored ECG signal on a map of the heart includes: (a) assigning (i) a first graphical representation to the first set and the first attribute of the ECG signal, and assigning (ii) a second graphical representation to the second set and the second attribute of the ECG signal, and (b) displaying one or both of the following on the one map of the heart: (i) the first set and the second set, and (ii) the first attribute and the second attribute.

[0085] Example 5

[0086] A method according to Example 3, wherein displaying the stored ECG signal on multiple maps includes: (a) assigning (i) a first graphical representation to the first set and the first attribute of the ECG signal, and assigning (ii) a second graphical representation to the second set and the second attribute of the ECG signal, and (b) displaying (i) one or both of the first set and the first attribute on a first map of the heart, and displaying (ii) one or both of the second set and the second attribute on a second map of the heart that is different from the first map.

[0087] Example 6

[0088] The method according to embodiments 1-2, wherein the first attribute comprises focus and the second attribute comprises a gradient of atrial fibrillation cycle length (ACLV).

[0089] Example 7

[0090] A method according to embodiments 1 to 6, wherein for each of the electrodes, calculating the positioning stability includes: (i) maintaining the given threshold indicating the positioning stability, (ii) calculating the standard deviation (SD) of the position signal for each of the electrodes using the position signal received from each of the electrodes along the predefined time interval, and (iii) comparing between the given threshold and the calculated SD for each of the electrodes.

[0091] Example 8

[0092] A method according to embodiments 1 to 6, wherein placing the electrodes in contact with tissue of the heart includes placing an array of the electrodes to cover a selected segment of the heart, and wherein the predefined time interval includes selecting a duration of the predefined time interval between 1 second and 10 seconds.

[0093] Example 9

[0094] A method according to Example 8, wherein the method includes moving the array of electrodes to an additional segment of the heart and placing the electrodes in contact with tissue of the additional segment, and repeating: (a) receiving the position signal and the ECG signal from each of the electrodes along a given time interval, (b) calculating the positioning stability along the given time interval for each of the electrodes, (c) calculating whether the ECG signal indicates the AF for the electrodes whose positioning stability has an error less than a given threshold, and (d) storing the ECG signal indicating the AF.

[0095] Example 10

[0096] A method according to Example 9, wherein the tissue is positioned at a first location in the heart and the additional segment is positioned at a second location in the heart different from the first location, and wherein the predefined time interval and the given time interval have similar durations.

[0097] Embodiment 11

[0098] A system (22), comprising:

[0099] (i) a processor (42) configured to: (a) receive, during a predefined time interval, for each electrode (55, 55a, 55b, 55c, 55d) of a catheter having a plurality of electrodes (55, 55a, 55b, 55c, 55d) placed in contact with tissue of a heart (26) of a patient (28): (i) a position signal indicative of a position of the electrode (55, 55a, 55b, 55c, 55d), and (ii) a position signal generated by the electrode (55, 55a, 55b, 55c, 55d). a, 55b, 55c, 55d), (b) calculating, based on the position signal, for each of the electrodes (55, 55a, 55b, 55c, 55d), a positioning stability along the predefined time interval, and (c) for the electrodes (55, 55a, 55b, 55c, 55d) whose positioning stability has an error less than a given threshold, calculating whether the ECG signal indicates atrial fibrillation (AF) in the heart (26); and

[0100] (ii) a memory (50) configured to store the ECG signal indicative of the AF.

[0101] Example 12

[0102] A system according to embodiment 11, wherein the processor is configured to store in the memory: (i) a first set of the ECG signals calculated with a first attribute indicative of the AF, and (ii) a second set of the ECG signals different from the first set calculated with a second attribute indicative of the AF, wherein the second attribute is different from the first attribute.

[0103] Embodiment 13

[0104]

[00136] The system of Example 12 wherein the method includes a display configured to display the stored ECG signals on one or more maps of the heart.

[0105] Embodiment 14

[0106] A system according to Example 13, wherein the processor is configured to: (i) assign a first graphical representation to the first set and the first attribute of the ECG signal, and (ii) assign a second graphical representation to the second set and the second attribute of the ECG signal, and wherein the display is configured to display one or both of the following on the one map of the heart: (i) the first set and the second set, and (ii) the first attribute and the second attribute.

[0107] Embodiment 15

[0108] A system according to Example 13, wherein the processor is configured to: assign (i) a first graphical representation to the first set and the first attribute of the ECG signal, and assign (ii) a second graphical representation to the second set and the second attribute of the ECG signal, and wherein the display is configured to: display (i) one or both of the first set and the first attribute on a first map of the heart, and display (ii) one or both of the second set and the second attribute on a second map of the heart that is different from the first map.

[0109] Example 16

[0110] A system as in embodiments 11-12, wherein the first attribute comprises focus and the second attribute comprises a gradient of atrial fibrillation cycle length (ACLV).

[0111] Embodiment 17

[0112] A system according to embodiments 11 to 16, wherein the processor is configured to calculate the positioning stability for each of the electrodes by: (i) maintaining the given threshold indicating the positioning stability, (ii) calculating the standard deviation (SD) of the position signal for each of the electrodes using the position signal received from each of the electrodes along the predefined time interval, and (iii) performing a comparison between the given threshold and the calculated SD for each of the electrodes.

[0113] Embodiment 18

[0114] A system according to embodiments 11 to 16, wherein the electrodes of the catheter are arranged in an array for covering a selected segment of the heart, and wherein the processor is configured to select the predefined time interval by selecting a duration of the predefined time interval between 1 second and 10 seconds.

[0115] Embodiment 19

[0116] A system according to Example 18, wherein the array of electrodes is moved to an additional segment of the heart and the electrodes are placed in contact with tissue of the additional segment, and wherein the processor is configured to repeat: (a) receiving the position signal and the ECG signal from each of the electrodes along a given time interval, (b) calculating the positioning stability along the given time interval for each of the electrodes, (c) calculating whether the ECG signal indicates the AF for the electrodes whose positioning stability has an error less than a given threshold, and wherein the memory is configured to repeat the storage of the ECG signal indicating the AF.

[0117] Embodiment 20

[0118] A system according to Example 19, wherein the tissue is positioned at a first location in the heart and the additional segment is positioned at a second location in the heart different from the first location, and wherein the processor is configured to set similar durations to (i) the predefined time interval, and (ii) the given time interval.

[0119] It should therefore be understood that the above embodiments 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 various features described above, as well as variations and modifications thereof, which will occur to those skilled in the art upon reading the above description, and which are not disclosed in the prior art.

Claims

1. A method, comprising: inserting a catheter having a plurality of electrodes into the patient's heart and placing the electrodes in contact with tissue of the heart; receiving, for each of the electrodes during a predefined time interval: (i) a position signal indicative of a position of the electrode, and (ii) an electrocardiogram (ECG) signal acquired by the electrode; calculating, for each of the electrodes, a positioning stability along the predefined time interval based on the position signal; calculating, for the electrodes whose positioning stability has an error less than a given threshold, whether the ECG signal indicates atrial fibrillation (AF) in the heart; and The ECG signal indicative of the AF is stored.

2. A method according to claim 1, wherein storing the ECG signals indicating the AF includes storing: (i) a first set of the ECG signals calculated with a first attribute indicating the AF, and (ii) a second set of the ECG signals different from the first set calculated with a second attribute indicating the AF, wherein the second attribute is different from the first attribute.

3. A method according to claim 2 and comprising displaying the stored ECG signals on one or more maps of the heart.

4. The method of claim 3, wherein displaying the stored ECG signal on a map of the heart comprises: (a) assigning (i) a first graphical representation to the first set and the first attribute of the ECG signal, and assigning (ii) a second graphical representation to the second set and the second attribute of the ECG signal, and (b) displaying on the one map of the heart one or both of: (i) the first set and the second set, and (ii) the first attribute and the second attribute.

5. The method of claim 3, wherein displaying the stored ECG signals on a plurality of maps comprises: (a) assigning (i) a first graphical representation to the first set and the first attribute of the ECG signal, and assigning (ii) a second graphical representation to the second set and the second attribute of the ECG signal, and (b) displaying (i) one or both of the first set and the first attribute on a first map of the heart, and displaying (ii) one or both of the second set and the second attribute on a second map of the heart that is different from the first map.

6. The method of claim 2, wherein the first attribute comprises focus and the second attribute comprises a gradient of atrial fibrillation cycle length (ACLV).

7. The method of claim 1 , wherein for each of the electrodes, calculating the positioning stability comprises: (i) maintaining said given threshold value indicative of said positioning stability, (ii) calculating a standard deviation (SD) of the position signal for each of the electrodes using the position signal received from each of the electrodes along the predefined time interval, and (iii) performing a comparison between the given threshold and the calculated SD for each of the electrodes.

8. The method of claim 1 , wherein placing the electrodes in contact with tissue of the heart comprises placing an array of the electrodes for covering a selected region of the heart, and wherein the predefined time interval comprises selecting a duration of the predefined time interval between 1 second and 10 seconds.

9. A method according to claim 8, and the method includes moving the array of electrodes to an additional segment of the heart and placing the electrodes in contact with tissue of the additional segment, and repeating: (a) receiving the position signal and the ECG signal from each of the electrodes along a given time interval, (b) calculating the positioning stability along the given time interval for each of the electrodes, (c) calculating whether the ECG signal indicates the AF for the electrodes whose positioning stability has an error less than a given threshold, and (d) storing the ECG signal indicating the AF.

10. The method of claim 9, wherein the tissue is positioned at a first location in the heart and the additional segment is positioned at a second location in the heart different from the first location, and wherein the predefined time interval and the given time interval have similar durations.

11. A system, comprising: A processor, the processor being configured to: receiving, during a predefined time interval, for each electrode of a catheter having a plurality of electrodes placed in contact with tissue of a patient's heart: (i) a position signal indicative of the position of the electrode, and (ii) an electrocardiogram (ECG) signal acquired by the electrode; calculating, for each of the electrodes, a positioning stability along the predefined time interval based on the position signal; as well as calculating, for the electrodes whose positioning stability has an error less than a given threshold, whether the ECG signal indicates atrial fibrillation (AF) in the heart; and A memory configured to store the ECG signal indicative of the AF.

12. A system according to claim 11, wherein the processor is configured to store in the memory: (i) a first set of the ECG signals calculated with a first attribute indicating the AF, and (ii) a second set of the ECG signals calculated with a second attribute indicating the AF that is different from the first set, wherein the second attribute is different from the first attribute.

13. A system according to claim 12, and comprising a display configured to display the stored ECG signals on one or more maps of the heart.

14. A system according to claim 13, wherein the processor is configured to: (i) assign a first graphical representation to the first set and the first attribute of the ECG signal, and (ii) assign a second graphical representation to the second set and the second attribute of the ECG signal, and wherein the display is configured to display one or both of the following on the one map of the heart: (i) the first set and the second set, and (ii) the first attribute and the second attribute.

15. A system according to claim 13, wherein the processor is configured to: assign (i) a first graphical representation to the first set and the first attribute of the ECG signal, and assign (ii) a second graphical representation to the second set and the second attribute of the ECG signal, and wherein the display is configured to: display (i) one or both of the first set and the first attribute on a first map of the heart, and display (ii) one or both of the second set and the second attribute on a second map of the heart that is different from the first map.

16. The system of claim 12, wherein the first attribute comprises focus and the second attribute comprises a gradient of atrial fibrillation cycle length (ACLV).

17. A system according to claim 11, wherein the processor is configured to calculate the positioning stability for each of the electrodes by: (i) maintaining the given threshold indicating the positioning stability, (ii) calculating the standard deviation (SD) of the position signal for each of the electrodes using the position signal received from each of the electrodes along the predefined time interval, and (iii) comparing between the given threshold and the calculated SD for each of the electrodes.

18. The system of claim 11, wherein the electrodes of the catheter are arranged in an array for covering a selected region of the heart, and wherein the processor is configured to select the predefined time interval by selecting a duration of the predefined time interval between 1 second and 10 seconds.

19. A system according to claim 18, wherein the array of electrodes is moved to an additional segment of the heart and the electrodes are placed in contact with tissue of the additional segment, and wherein the processor is configured to repeat: (a) receiving the position signal and the ECG signal from each of the electrodes along a given time interval, (b) calculating the positioning stability along the given time interval for each of the electrodes, (c) calculating whether the ECG signal indicates the AF for the electrodes whose positioning stability has an error less than a given threshold, and wherein the memory is configured to repeat the storage of the ECG signal indicating the AF.

20. A system according to claim 19, wherein the tissue is positioned at a first location in the heart and the additional segment is positioned at a second location in the heart different from the first location, and wherein the processor is configured to set similar time durations to (i) the predefined time interval, and (ii) the given time interval.

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