Automatic storage and display of ECG signals indicative of atrial fibrillation

Abstract

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

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

[0003] For example, U.S. Patent No. 10,939,863 describes a method including receiving, in a processor, a two-dimensional (2D) electro-anatomical (EA) map of an interior surface of at least a portion of a cavity of a patient's organ, the 2D EA map including electrophysiological (EP) values ​​measured at respective locations on the interior surface. A complex analytic function is fitted to a set of EP values ​​measured within a given region of the 2D EA map. Singular points are identified in the fitted complex analytic function. The region is projected onto a three-dimensional (3D) EA map of the interior surface. At least a portion of the 3D EA map is presented to a user, including showing pro-arrhythmic EP activity at locations on the 3D EA map that correspond to the singular points identified in the fitted complex analytic function. [Brief description of the drawings]

[0004] The present disclosure will become more fully understood from the following detailed description of the embodiments thereof, taken in conjunction with the drawings, in which: [Figure 1] FIG. 1 is a schematic, pictorial illustration of a catheter-based position tracking and ablation system, according to an embodiment of the present disclosure. [Diagram 2] 1 is a schematic, pictorial illustration of a segment of a heart and an electrocardiogram (ECG) signal sensed in the segment and indicative of Atrial Fibrillation (AF) in the heart, in accordance with an embodiment of the present disclosure. [Diagram 3] 1 is a flowchart that generally illustrates a method for automatically storing and presenting an ECG signal indicative of AF, in accordance with an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0005] overview The embodiments 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.

[0006] In some embodiments, the system comprises a catheter having a distal-end assembly (DEA) including a plurality of (e.g., about 48) electrodes arranged in an array covering a compartment within the heart. The system further comprises patch electrodes attached to the skin of the patient's chest and a magnetic-based position sensor configured to generate a position signal indicative of a position (in a predefined coordinate system) of the DEA within the patient's heart. Each of the electrodes is configured to generate an impedance-based position signal indicative of the position of the respective electrode in said predefined coordinate system when placed in contact with cardiac tissue. It is noted that the impedance-based position signal is generated based on impedance measurements between (i) each of the electrodes of the DEA and (ii) one or more of the patch electrodes.

[0007] In some embodiments, each of the electrodes of the DEA is configured, when placed in contact with tissue, to generate an electrocardiogram (ECG) signal that is sensed in the tissue.

[0008] In some embodiments, the system includes a processor configured to receive, for each electrode of the catheter placed in contact with tissue during a predetermined time period, (i) a position signal indicative of the position of the electrode, and (ii) an ECG signal acquired by each electrode, as described above.

[0009] In some embodiments, the processor is configured to calculate a positioning stability along a predefined time interval for each of the electrodes based on the position signal. The positioning stability can be calculated using an Advanced Catheter Location (ACL) catheter position tracking method, which is described in detail in FIG. 1 below. In this embodiment, an impedance-based position signal is used in the ACL, and a standard deviation (SD) of the impedance-based position signal is calculated along a predefined time interval, for example, the duration of the time interval may be about 2.5 seconds. The processor is configured to hold a threshold value indicative of a positioning stability of each electrode of the DEA. For example, the threshold value may have a value of about 3 mm, such that an electrode of the DEA whose position signal has a SD less than about 3 mm is referred to herein as a qualified electrode, and an electrode of the DEA whose position signal has a SD greater than about 3 mm is referred to herein as a non-qualified electrode.

[0010] In some embodiments, the processor is configured to receive ECG signals sensed and acquired by electrodes of the DEA during a predetermined time interval.

[0011] In some embodiments, the processor is configured to determine whether, for qualified electrodes, i.e., electrodes whose positioning stability has an error (e.g., SD) less than a given threshold (e.g., 3 mm), the ECG signal indicates atrial fibrillation (AF) in the heart.

[0012] In some examples, the system includes a memory, and the processor is configured to control the memory to automatically store the ECG signal identified as indicative of AF. It is noted that the ECG signal may exhibit different attributes indicative of AF.

[0013] In some embodiments, 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 indicative of a first attribute of the indicated AF are marked using a first tag, and ECG signals indicative of a second attribute of the indicated AF (different from the first attribute) are marked using a second tag different from the first tag. In an alternative embodiment, the processor is configured to display on the display (i) a first map of at least a segment of the heart with ECG signals indicative of the first attribute, and (ii) a second map of at least that segment of the heart with ECG signals indicative of the second attribute. In other words, the ECG signals may be presented on different maps of the heart.

[0014] The disclosed techniques improve the quality of electrophysiological (EP) mapping by eliminating ECG signals acquired with electrodes that have insufficient positioning stability. Additionally, the disclosed techniques reduce the duration of the EP mapping procedure by (i) using a multi-electrode catheter that covers a compartment in the tissue of interest and simultaneously acquiring location and ECG signals using the electrodes of the catheter, and (ii) automating the storage of ECG signals indicative of atrial fibrillation in the heart and the display of each ECG signal on one or more maps of the heart.

[0015] System Description FIG. 1 is a schematic, pictorial illustration of a catheter-based position tracking and ablation system 20, in accordance with an embodiment of the present disclosure.

[0016] In some embodiments, system 20 includes a catheter 22 (in this embodiment a multi-spline and multi-electrode cardiac catheter, described below) and a control console 24. In the embodiments described herein, catheter 22 may be used for any suitable therapeutic and / or diagnostic purpose, such as, but not limited to, sensing electroanatomical (EA) information in tissue of interest and applying ablation signals to tissue of heart 26. In the context of this disclosure, the term information refers to the spatial location of each electrode at the distal end of the catheter and the electrocardiogram (ECG) signals sensed by the respective electrodes of catheter 22.

[0017] In some embodiments, the console 24 includes a processor 42, typically a general-purpose computer, with 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 may be programmed with software to perform functions used by the system, and the processor 42 is configured to store data for the software in memory 50. The software may be downloaded to the console 24 in electronic form, for example, over a network, or may be provided on a non-transitory tangible medium, such as an optical, magnetic, or electronic storage medium. Alternatively, some or all of the functions of the processor 42 may be performed using an application-specific integrated circuit (ASIC) or any suitable type of programmable digital hardware component.

[0018] Referring now to inset 25, in some embodiments, catheter 22 comprises a distal end assembly (DEA) 40 having a plurality (e.g., six) splines, each of which comprises a plurality (e.g., eight) electrodes configured to sense signals from tissue of heart 26.

[0019] Reference is now made to inset 48, which shows DEA 40. In this embodiment, DEA 40 comprises a Picasso™ catheter manufactured by Biosense Webster Inc. (Irvine, Calif.). The Picasso™ catheter comprises six splines 54 arranged at a distance 70 from each other to cover the surface of the tissue of heart 26. Note that splines 54 are flexible to conform to the tissue of interest. Each spline 54 has eight electrodes 55 that, when placed in contact with tissue of heart 26, are configured to generate signals indicative of (i) an electrocardiogram (ECG) signal in the respective tissue, and (ii) an impedance indicative of the position of each electrode in the XYZ coordinate system of system 20, which are described in more detail below.

[0020] In this embodiment, the electrodes 55 are located at a distance 72 from each other. The ECG signal and the sensed impedance may include unipolar or bipolar signals, as described below. In other embodiments, the DEA 40 may include any other suitable type of DEA having multiple electrodes arranged in an array covering a suitable area of ​​tissue of the heart 26.

[0021] Referring again to the overall view of FIG. 1 , in some embodiments, the catheter 22 comprises a shaft 23 for inserting the DEA 40 to a target location for ablation of tissue within the heart 26. During an electrophysiology (EP) mapping and / or ablation procedure, a physician 30 inserts the catheter 22 through the vascular system of a patient 28 lying on a table 29. The physician 30 moves the DEA 40 to the target location within the heart 26 using a manipulator 32 near the proximal end of the catheter 22, which is connected to an interface circuit of a processor 42. In this embodiment, the target location may include tissue having one or more sites intended to be diagnosed (and optionally ablated) by the DEA 40.

[0022] In some embodiments, system 20 includes an external patch electrode 49 configured to couple to the skin on the chest of patient 28 and to sense signals indicative of an ECG and / or impedance.

[0023] In some embodiments, processor 42 is configured to generate position signals indicative of the position of each electrode 55 in an XYZ coordinate system of heart 26 based on signals received from electrodes 55 (of DEA 40) and external patch electrodes 49. The position signals are generated using an Advanced Catheter Location (ACL) catheter position tracking method, described below. In this embodiment, processor 42 is connected to patch electrodes 49 via wires passing through cable 37.

[0024] In some embodiments, processor 42 is configured to determine position coordinates of each electrode 55 based on the impedance measured between each electrode 55 and each of the patch electrodes 49. ACL methods of electrode position sensing using system 20 have been implemented in a variety of medical applications, such as the CARTO™ system manufactured by Biosense Webster Inc. (Irvine, California), and are described in more detail in U.S. Patent Nos. 7,756,576, 7,869,865, and 7,848,787.

[0025] Reference is now made again to inset 48. In some embodiments, catheter 22 comprises a position sensor 39 of a magnetic-based position tracking system that is coupled to a distal end of catheter 22, for example, in close proximity to DEA 40. In this embodiment, position sensor 39 comprises a magnetic position sensor, although in other embodiments any other suitable type of position sensor (e.g., other than magnetic-based) may be used.

[0026] Referring again to the overall view of Figure 1, in some embodiments, during navigation of the DEA 40 within the heart 26, the processor 42 receives signals from a magnetic position sensor 39 in response to a magnetic field from an external magnetic field generator 36, e.g., to determine the position of the DEA 40 within the heart 26. In some embodiments, the console 24 includes a driver circuit 34 configured to drive the magnetic field generator 36. The magnetic field generator 36 is placed at a known position outside the patient 28, e.g., beneath the table 29.

[0027] In some embodiments, the processor 42 is configured to display, for example on a display 46 of the console 24, the tracked position of the DEA 40 superimposed on an image 44 of the heart 26, the image 44 being typically a three-dimensional (3D) image.

[0028] Position sensing methods using external magnetic fields have been implemented in a variety of medical applications, for example, in the CARTO™ system manufactured by Biosense Webster Inc. (Irvine, Calif.), and are described in detail in U.S. Pat. Nos. 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612, and 6,332,089, WO 96 / 05768, and U.S. Patent Application Publication Nos. 2002 / 0065455(A1), 2003 / 0120150(A1), and 2004 / 0068178(A1).

[0029] In some embodiments, the processor 42 is configured to use the magnetic-based position signal and the ACL-based position signal to, for example, calculate a roll angle of the DEA 40 to correct an ACL-based position of one or more electrodes 55. Furthermore, based on the magnetic-based position signal, the processor 42 is configured to adjust an orientation of the (flat array of) the DEA 40 relative to the tissue of interest of the heart 26.

[0030] One embodiment 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 No. 2019 / 0021789, inventors of which are Gliner et al. and assigned to the assignee of the present disclosure.

[0031] In some embodiments, 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 two poles 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.

[0032] This particular configuration of system 20 is presented as an example to illustrate the particular problems addressed by embodiments of the present disclosure and to demonstrate the application of these embodiments in improving the performance of such systems, however, embodiments of the present disclosure are in no way limited to this particular type of exemplary system, and the principles described herein may be applied to other types of medical systems as well.

[0033] Method for automatically storing and displaying ECG signals indicative of atrial fibrillation FIG. 2 is a schematic illustration of a section 27 (FIG. 1) of heart 26 and an electrocardiogram (ECG) signal sensed by electrodes 55 of DEA 40 within section 27 and indicative of atrial fibrillation (AF) in heart 26, in accordance with an embodiment of the present disclosure.

[0034] 1 above, physician 30 moves DEA 40 to the tissue of interest, in this example, section 27 located on the inner wall of the atrium of heart 26. In some embodiments, splines 54 are placed over section 27 such that at least some, typically all 48, electrodes 55 are placed in contact with tissue of section 27.

[0035] In some embodiments, the processor 42 is configured to receive a plurality of position signals from each of the position sensor 39 and the ACL position tracking system during a predetermined time interval (e.g., approximately 1 second to 10 seconds), as described in FIG. 1 above. In this embodiment, the time interval may be approximately 2.5 seconds, during which the processor 42 may receive approximately 150 sets of position signals (i.e., approximately every 16.7 milliseconds). Based on the approximately 150 sets of position signals received during the time interval, the processor 42 is configured to estimate a position of each electrode 55 (and the DEA 40) along the time interval. Additionally, the processor 42 is configured to calculate, for each electrode 55, an average position and a standard deviation (SD) of the positions along the 2.5 second time interval.

[0036] In some embodiments, the processor 42 is configured to maintain a threshold indicative of the positioning stability along a time interval for each electrode 55. In the context of this disclosure and in the claims, the term "positioning stability along a time interval" refers to the deviation of a calculated position of a given electrode 55 relative to an average position of the given electrode 55 calculated based on position signals received during a given time interval (e.g., 2.5 seconds).

[0037] In this example, the threshold has a value of approximately 3 mm, so that if the SD of the positions 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 is indicative of AF of the heart 26. Such an ECG signal is also referred to herein as a qualified ECG signal. If the SD is greater than approximately 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 is indicative of AF of the heart 26. Such an ECG signal is also referred to herein as an unqualified ECG signal.

[0038] In some examples, if an insufficient number of electrodes (e.g., less than three electrodes) with an SD less than 3 mm are identified, physician 30 defines a new time interval (having the same duration of approximately 2.5 seconds or a different duration) for repeating the collection of position signals and ECG signals from tissue within segment 27 of heart 26.

[0039] The term "about" or "approximately" as used in the context of this disclosure and in the claims with respect to any numerical value or range of numerical values ​​is intended to indicate a suitable tolerance of dimensions that enables (i) a component part or collection of components, and (ii) measurable abstract features, such as the aforementioned time intervals and measured values ​​related to ECG and location signals, to function according to their intended purpose as described herein.

[0040] In some examples, after obtaining ECG measurements from a sufficient number of electrodes 55 (e.g., three or more), processor 42 is configured to calculate certain features and / or attributes and / or parameters indicative of whether the ECG signals are indicative of AF in heart 26. It is noted that ECG signals sensed by electrodes 55 with a SD greater than 3 are not eligible to provide an indication of AF, and thus processor 42 is configured to filter out these ECG signals from the calculation of the above-mentioned features and / or attributes and / or parameters.

[0041] In the context of this disclosure and the claims, the terms “features,” “attributes,” “parameters,” and “criteria,” as well as grammatical variations thereof, are used interchangeably to refer to indications of whether the above-mentioned ECG signal is indicative of AF in heart 26.

[0042] It should be noted that atrial fibrillation causes changes in the calculated parameters over time. Therefore, it is important to select parameters that can be indicative of AF. For example, atrial fibrillation cycle length (AFCL) may be indicative of AF in the heart 26. In this example, an AFLC having a value of about 120-200 milliseconds (ms) indicates a healthy area in the heart 26, while an AFCL value less than about 120 ms or greater than about 200 ms indicates a problem that may be related to AF in the heart 26. More specifically, the gradient of the AFCL values ​​along different locations along the tissue of the atrium can be used to map AF in each atrium. Such techniques are described, for example, in commonly assigned U.S. Patent No. 11,160,481. It should be noted that if the positioning stability of one or more electrodes used to sense the ECG signal is insufficient (e.g., having an SD greater than about 3 mm), the accuracy of the calculated AFCL values ​​and gradients may be insufficient.

[0043] In some embodiments, processor 42 is configured to apply various types of filters to ECG signals received from electrodes 55 having an SD less than 3 mm to determine whether the qualifying ECG signals are indicative of AF of heart 26. In some embodiments, upon identifying the qualifying ECG signals to be used to calculate parameters indicative of AF, processor 42 is configured to automatically store these ECG signals, for example, in memory 50 of console 24.

[0044] In some embodiments, based on the stored ECG signals, processor 42 is configured to identify indicators of AF in segment 27 of heart 26. In the embodiment of FIGURE 2, processor 42 is configured to display on a 3D anatomical map of segment 27, for example on the surface of the tissue of segment 27, conduction velocity vectors 66 indicating the propagation direction and velocity of electrophysiological (EP) signals.

[0045] In some embodiments, processor 42 is configured to identify a pattern indicative of AF. In the embodiment of FIG. 2, processor 42 is configured to identify, within partition 27, partition 77 having a focal point 61 within the tissue of heart 26. Referring now to inset 63, in some embodiments, conduction velocity vectors 66 are positioned as if emanating from focal point 61. More specifically, focal point 61 is a virtual point or area that is the origin of vector 66, as shown in inset 63. In such an example, processor 42 can apply various techniques of pattern recognition to identify focal point 61 within partition 77.

[0046] Referring again to the overall view of FIG. 2, in some embodiments, if three points located within a subdivision of partition 27 have a gradient of AFCL values, this subdivision may be indicative of AF. In the embodiment of FIG. 2, based on the qualifying ECG signals, processor 42 calculates AFCL values ​​of approximately 150 ms, 200 ms, and 270 ms at points 74, 75, and 76 along line 73, respectively. This gradient of AFCL values ​​indicates potential AF, and thus processor 42 is configured to identify and store ECG signals measured by electrodes 55 in each subdivision proximate line 73. Furthermore, processor 42 is configured to display line 73 or any other indication of the AFCL gradient on the map of partition 27.

[0047] Next, reference is made to subdivision 64 of the map of division 27. In some embodiments, some of the electrodes 55 are located within the area of ​​subdivision 64, more specifically, electrodes 55a, 55b, 55c and 55d are among these electrodes.

[0048] Reference is now made to inset 67, which shows a family of graphs 65 presenting the successive activation variations of successive bipolar ECG signals produced by electrodes 55 located within subdivision 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 shown along axis 51, and the amplitude of the signal over time is shown along axis 53. Furthermore, the time interval of the graphs spans 100% of the atrial fibrillation cycle length mentioned above.

[0049] In this example, the family of graphs 65 includes vertical markers 57 and 59. As shown in inset 67, the peaks indicative of activation in each ECG signal (e.g., the R peak) are offset relative to one another along axis 53. For example, the peak in graph 88a is at marker 59, but the peaks in graphs 88b, 88c, and 88d are shifted in location such that they are not at marker 59. In another example, the peaks in graphs 88b and 88c are prior to the time of marker 57, and the peaks in graphs 88a and 88d are after the time of marker 57. This variation in successive activations of successive bipolar ECG signals may be indicative of an AF source.

[0050] In other examples, processor 42 is configured to identify other parameters and / or features and / or attributes indicative of AF using any suitable calculations or manipulations on a qualified ECG signal, for example, as described above.

[0051] FIG. 3 is a flow chart that generally illustrates a method for automatically storing and presenting ECG signals indicative of AF in heart 26, in accordance with an embodiment of the present disclosure.

[0052] The method begins with a catheter insertion step 100, in which the physician 30 inserts the DEA 40 (of the catheter 22) having a plurality (e.g., 48) of electrodes 55, as described in FIG. 1 above. In a positioning stability check step 102, the physician 30 places the electrodes 55 in contact with tissue of interest in the compartment 27 in the heart 26. In some embodiments, the processor 42 receives (i) position signals from the electrodes 55 and the patch electrode 49, and (ii) an ECG signal from the electrodes 55, during a predetermined time period, e.g., about 2.5 seconds. Furthermore, the processor 42 checks the positioning stability of each electrode 55 based on the received position signals, as described in detail in FIG. 1 and FIG. 2 above.

[0053] In a first decision step 104, processor 42 compares (i) a threshold having a predetermined value (e.g., about 3 mm) with (ii) the calculated SD of the position signals received along the time interval, as described above in Figure 2, for each electrode 55. If the calculated SD is greater than the threshold, the method returns to step 102.

[0054] In some embodiments, processor 42 also defines a minimum number of qualified electrodes 55, i.e., electrodes 55 whose positioning stability error (i.e., SD) is less than a threshold value. If the number of qualified electrodes 55 is less than the minimum number, the method returns to step 102. For example, if only one or two electrodes 55 (e.g., out of 48 electrodes of DEA 40) have a calculated SD less than about 3 mm, the method returns to step 102.

[0055] If the SD of the position signal calculated for a given electrode 55 is less than the 3 mm threshold, then the given electrode 55 is qualified and the ECG signal generated by the given electrode 55 during the same 2.5 second time interval is used by the processor 42 in later steps of the method.

[0056] In some embodiments, if the number of qualified electrodes is greater than a minimum number defined by the processor 42, the method proceeds to a second decision step 106. Note that in step 106, only the ECG signals of the qualified electrodes are used. In step 106, the processor 42 is configured to determine whether the ECG signals generated by the qualified electrodes 55 during the time interval are indicative of atrial fibrillation (AF) in the heart 26. In other words, the processor 42 is configured to check whether the ECG signals generated by the qualified electrodes 55 during the time interval indicate a criterion that indicates whether AF is met. For example, the processor 42 can apply various techniques of pattern recognition to identify the local points 61 within the partition 77, as described in FIG. 2 above.

[0057] If processor 42 identifies the ECG signal in step 106 above as indicative of AF, the method proceeds to an automatic storage step 108. In step 108, which ends the method, processor 42 automatically stores in memory 50 the ECG signal used to calculate parameters indicative of AF, as described in FIGURE 2 above. In some embodiments, processor 42 is configured to visualize criteria indicative of AF on a suitable anatomical or electro-anatomical map of heart 26. The visualized criteria are based on calculations of ECG signals indicative of AF in heart 26, as described in FIGURE 2 above.

[0058] In some examples, if processor 42 does not identify that the ECG signal in step 106 above is indicative of AF, the method returns to step 102 and physician 30 moves DEA 40 to cover another segment within heart 26 other than segment 27. Note 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 were placed in contact with segment 27, e.g., 2.5 seconds. In alternative examples, processor 42 and / or physician 30 may select a different duration of the time interval for sensing position signals and ECG signals in the other segment.

[0059] In some embodiments, the disclosed techniques provide the physician 30 with automatic storage of ECG signals that are (i) acquired at stable positioning of each electrode 55, (ii) acquired in a relatively large section of the heart 26 (e.g., section 27) covered by the DEA 40 during a short time interval (e.g., about 2.5 seconds), and (iii) indicative of AF in the heart 26. In principle, it is possible to acquire ECG signals by visiting point by point in section 27, but this process may significantly prolong the procedure, and since the points are not acquired during the same time interval, the results may not be indicative of AF as compared to results obtained by the method of FIG. 3 using the technique described in FIG. 2 above.

[0060] In other examples, ECG mapping ends when (i) physician 30 decides to acquire ECG signals only in segment 27, or (ii) after repeating steps 102-108 in additional segments of heart 26. In such examples, processor 42 presents stored ECG signals indicative of AF on one or more maps of heart 26.

[0061] In some embodiments, at least one of the stored ECG signals may be displayed on a separate map. For example, processor 42 may generate a map of heart 26 having local points 61 identified in one or more compartments of heart 26.

[0062] In other embodiments, processor 42 may display all ECG signals that indicate AF and that are automatically stored in memory 50 on a single map of heart 26, for example, as shown in the map of section 27 in FIG. 2 above. In such embodiments, processor 42 may be configured to add different tags to ECG signals that include different attributes of AF. For example, (i) section 77, which indicates local point 61, and (ii) line 73, which indicates the AFCL gradient along points 74-76, may be bot shown on the map of section 27 using different graphical representations and / or tagging, as shown and described in FIG. 2 above.

[0063] The method of Figure 3 is simplified and provided by way of example for conceptual clarity. In other embodiments, Figure 3 may include additional or alternative steps, for example using a different implementation or order of steps, in accordance with the techniques disclosed in Figures 1-3 above.

[0064] The examples described herein primarily address automatically storing and presenting ECG signals indicative of atrial fibrillation in the heart. The methods and systems described herein may also be used for other applications, such as procedures associated with other types of heart rhythm disorders, such as, but not limited to, detection and / or treatment of Ventricular Tachycardia (VT) and Brugada Syndrome. EXAMPLES

[0065] 1. A method comprising: (i) inserting a catheter (22) having a plurality of electrodes (55) into a heart (26) of a patient (28) and placing the electrodes (55, 55a, 55b, 55c, 55d) in contact with tissue of the heart (26); (ii) for each of the electrodes (55, 55a, 55b, 55c, 55d), receiving, during a predetermined time interval, (i) a position signal indicative of a position of the electrode (55, 55a, 55b, 55c, 55d) and (ii) an electrocardiogram (ECG) signal acquired by the electrode (55, 55a, 55b, 55c, 55d); (iii) calculating, for each of the electrodes (55, 55a, 55b, 55c, 55d) a positioning stability along a predetermined time interval based on the position signal; (iv) for electrodes (55, 55a, 55b, 55c, 55d) having a positioning stability error less than a given threshold, determining whether the ECG signal is indicative of atrial fibrillation (AF) in the heart (26); (v) storing an ECG signal indicative of AF. EXAMPLES

[0066] 2. The method of example 1, wherein storing the ECG signals indicative of AF includes storing (i) a first set of ECG signals calculated on a first attribute indicative of AF, and (ii) a second set of ECG signals calculated on a second attribute indicative of AF, the second attribute being different from the first attribute. EXAMPLES

[0067] 3. The method of example 2, wherein the method further comprises displaying the stored ECG signals on one or more maps of the heart. EXAMPLES

[0068] The method of example 3, wherein displaying the stored ECG signals on a map of the heart includes: (a) (i) assigning a first graphical representation to a first set of ECG signals and first attributes, and (ii) assigning a second graphical representation to a second set of ECG signals and second attributes; and (b) displaying one or both of (i) the first set and the second set, and (ii) the first attributes and the second attributes, on the map of the heart. EXAMPLES

[0069] The method of example 3, wherein displaying the stored ECG signals on a plurality of maps includes: (a) (i) assigning a first graphical representation to a first set of ECG signals and a first attribute, and (ii) assigning a second graphical representation to a second set of ECG signals and a second attribute; and (b) (i) displaying one or both of the first set and the first attribute on a first map of the heart, and (ii) displaying one or both of the second set and the second attribute on a second map of the heart different from the first map. EXAMPLES

[0070] The method according to any one of the preceding claims, wherein the first attribute comprises a local point and the second attribute comprises a gradient of an atrial fibrillation cycle length (ACLV). EXAMPLES

[0071] The method of any one of Examples 1 to 6, wherein calculating the positioning stability includes, for each of the electrodes, (i) maintaining a given threshold indicative of the positioning stability, (ii) calculating a standard deviation (SD) of the position signals for each of the electrodes using the position signals received from each of the electrodes along a predetermined time interval, and (iii) comparing the calculated SD of each of the electrodes with the given threshold. EXAMPLES

[0072] The method of any one of Examples 1 to 6, wherein placing the electrodes in contact with the cardiac tissue comprises placing an array of electrodes to cover a selected section of the heart, and wherein the predetermined time interval comprises selecting a duration of the predetermined time interval between 1 second and 10 seconds. EXAMPLES

[0073] 9. The method of example 8, wherein the method includes moving the array of electrodes to additional compartments of the heart and placing the electrodes in contact with tissue of the additional compartments, and repeating the following: (a) receiving position signals and ECG signals from each of the electrodes along a given time interval; (b) calculating a positioning stability along the given time interval for each of the electrodes; (c) for electrodes whose positioning stability has an error less than a given threshold, determining whether the ECG signals are indicative of AF; and (d) storing the ECG signals indicative of AF. EXAMPLES

[0074] 10. The method of example 9, wherein the tissue is located at a first location within the heart and the additional compartment is located at a second location within the heart different from the first location, and the predetermined time interval and the given time interval have similar durations. EXAMPLES

[0075] A system (22), (i) a processor (42) for receiving, 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) during a predetermined time interval, (i) a position signal indicative of the position of the electrode (55, 55a, 55b, 55c, 55d) and (ii) an electrocardiogram signal acquired by the electrode (55, 55a, 55b, 55c, 55d). a processor (42) configured to receive an ECG signal, (b) calculate a positioning stability along a predetermined time interval for each of the electrodes (55, 55a, 55b, 55c, 55d) based on the position signal, and (c) determine whether the ECG signal is indicative of atrial fibrillation (AF) in the heart (26) for the electrodes (55, 55a, 55b, 55c, 55d) having a positioning stability error less than a given threshold; (ii) a memory (50), the memory (50) configured to store an ECG signal indicative of AF. EXAMPLES

[0076] 12. The system of example 11, wherein the processor is configured to store in the memory: (i) a first set of ECG signals calculated on a first attribute indicative of AF; and (ii) a second set of ECG signals calculated on a second attribute indicative of AF, the second attribute being different from the first attribute. EXAMPLES

[0077] The system of example 12, wherein the method comprises a display configured to display the stored ECG signals on one or more maps of the heart. EXAMPLES

[0078] The system of Example 13, wherein the processor is configured to (i) assign a first graphical representation to a first set of ECG signals and a first attribute, and (ii) assign a second graphical representation to a second set of ECG signals and a second attribute, and the display is configured to display one or both of (i) the first set and the second set, and (ii) the first attribute and the second attribute on a map of the heart. EXAMPLES

[0079] The system of Example 13, wherein the processor is configured to (i) assign a first graphical representation to a first set of ECG signals and a first attribute, and (ii) assign a second graphical representation to a second set of ECG signals and a second attribute, and the display is configured to (i) display one or both of the first set and the first attribute on a first map of the heart, and (ii) display one or both of the second set and the second attribute on a second map of the heart different from the first map. EXAMPLES

[0080] 13. The system of examples 11-12, wherein the first attribute comprises a local point and the second attribute comprises an atrial fibrillation cycle length (ACLV) gradient. EXAMPLES

[0081] The system described in Examples 11 to 16, wherein the processor is configured to calculate positioning stability for each of the electrodes by (i) maintaining a given threshold indicative of positioning stability, (ii) calculating a standard deviation (SD) of the position signals for each of the electrodes using the position signals received from each of the electrodes along a predetermined time interval, and (iii) comparing the calculated SD of each of the electrodes with the given threshold. EXAMPLES

[0082] The system described in Examples 11 to 16, wherein the electrodes of the catheter are arranged in an array to cover a selected section of the heart, and the processor is configured to select the predetermined time interval by selecting a duration of the predetermined time interval between 1 second and 10 seconds. EXAMPLES

[0083] The system of Example 18, wherein the array of electrodes is moved to an additional compartment of the heart and the electrodes are placed in contact with tissue of the additional compartment, and the processor is configured to repeat the steps of: (a) receiving position signals and ECG signals from each of the electrodes along a given time interval; (b) calculating a positioning stability along the given time interval for each of the electrodes; and (c) determining whether the ECG signals indicate AF for electrodes whose positioning stability has an error less than a given threshold; and the memory is configured to repeat the steps of storing the ECG signals indicative of AF. EXAMPLES

[0084] The system of Example 19, wherein the tissue is located at a first location within the heart and the additional compartment is located at a second location within the heart that is different from the first location, and the processor is configured to set (i) a predetermined time interval and (ii) a duration similar to the given time interval.

[0085] It will therefore be understood that the above-described embodiments are given by way of example, and that the present disclosure is not limited to what has been particularly shown and described above, but rather, the scope of the present disclosure includes both combinations and subcombinations of the various features described above, as well as variations and modifications thereof that would occur to one skilled in the art upon reading the foregoing description and that are not disclosed in the prior art.

[0086] [Embodiment] (1) A method comprising: inserting a catheter having a plurality of electrodes into a patient's heart and placing the electrodes in contact with tissue of the heart; receiving, for each of the electrodes, during a predetermined 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 predetermined time interval based on the position signals; For the electrodes having a positioning stability error less than a given threshold, determining whether the ECG signal is indicative of atrial fibrillation (AF) in the heart; and storing the ECG signal indicative of the AF. (2) The method of claim 1, wherein storing the ECG signals indicative of the AF includes storing (i) a first set of the ECG signals calculated under a first attribute indicative of the AF, and (ii) a second set of the ECG signals calculated under a second attribute indicative of the AF, the second attribute being different from the first attribute. (3) The method of embodiment 2, further comprising displaying the stored ECG signals on one or more maps of the heart. (4) The method of embodiment 3, wherein displaying the stored ECG signals on a map of the heart includes: (a)(i) assigning a first graphical representation to the first set of ECG signals and the first attribute, and (ii) assigning a second graphical representation to the second set of ECG signals and the second attribute; and (b) displaying one or both of (i) the first set and the second set, and (ii) the first attribute and the second attribute, on the map of the heart. (5) The method of embodiment 3, wherein displaying the stored ECG signals on a plurality of maps includes: (a)(i) assigning a first graphical representation to the first set of ECG signals and the first attribute, and (ii) assigning a second graphical representation to the second set of ECG signals and the second attribute; and (b)(i) displaying one or both of the first set and the first attribute on a first map of the heart, and (ii) displaying one or both of the second set and the second attribute on a second map of the heart different from the first map.

[0087] (6) The method of embodiment 2, wherein the first attribute includes a local point and the second attribute includes a gradient of an atrial fibrillation cycle length (ACLV). (7) The method of embodiment 1, wherein calculating the positioning stability includes, for each of the electrodes, (i) maintaining the given threshold indicative of the 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 predetermined time interval; and (iii) comparing the calculated SD of each of the electrodes with the given threshold. (8) The method of embodiment 1, wherein placing the electrodes in contact with the cardiac tissue includes placing an array of the electrodes to cover a selected section of the cardiac tissue, and wherein the predetermined time interval includes selecting a duration of the predetermined time interval between 1 second and 10 seconds. (9) The method of embodiment 8, comprising moving the array of electrodes to additional compartments of the heart and placing the electrodes in contact with tissue of the additional compartments; and repeating the steps of: (a) receiving the position signals and the ECG signals 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) for the electrodes having a positioning stability error less than a given threshold, determining whether the ECG signals are indicative of the AF; and (d) storing the ECG signals indicative of the AF. (10) The method of embodiment 9, wherein the tissue is located at a first location within the heart, the additional compartment is located at a second location within the heart different from the first location, and the predetermined time interval and the given time interval have similar durations.

[0088] (11) A system comprising: 1. A processor comprising: receiving, for each electrode of a catheter having a plurality of electrodes placed in contact with tissue of a patient's heart during a predetermined 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 predetermined time interval based on the position signal; a processor configured to determine whether the ECG signal is indicative of atrial fibrillation (AF) in the heart for the electrodes having a positioning stability error less than a given threshold; a memory configured to store the ECG signal indicative of the AF. (12) The system of claim 11, wherein the processor is configured to store in the memory: (i) a first set of the ECG signals calculated under a first attribute indicative of the AF; and (ii) a second set of the ECG signals calculated under a second attribute indicative of the AF, the second attribute being different from the first attribute. (13) The system of embodiment 12, further comprising a display configured to display the stored ECG signals on one or more maps of the heart. (14) The system of embodiment 13, wherein the processor is configured to (i) assign a first graphical representation to the first set of ECG signals and the first attribute, and (ii) assign a second graphical representation to the second set of ECG signals and the second attribute, and wherein the display is configured to display one or both of (i) the first set and the second set, and (ii) the first attribute and the second attribute, on the one map of the heart. (15) The system of embodiment 13, wherein the processor is configured to (i) assign a first graphical representation to the first set of ECG signals and the first attribute, and (ii) assign a second graphical representation to the second set of ECG signals and the second attribute, and wherein the display is configured to (i) display one or both of the first set and the first attribute on a first map of the heart, and (ii) display one or both of the second set and the second attribute on a second map of the heart different from the first map.

[0089] (16) The system of embodiment 12, wherein the first attribute includes a local point and the second attribute includes an atrial fibrillation cycle length (ACLV) slope. (17) The system of embodiment 11, wherein the processor is configured to calculate the positioning stability for each of the electrodes by: (i) maintaining the given threshold indicative of the 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 predetermined time interval; and (iii) comparing the calculated SD of each of the electrodes with the given threshold. (18) The system of embodiment 11, wherein the electrodes of the catheter are arranged in an array to cover a selected section of the heart, and the processor is configured to select the predetermined time interval by selecting a duration of the predetermined time interval between 1 second and 10 seconds. (19) The system of embodiment 18, wherein the array of electrodes is moved to an additional compartment of the heart and the electrodes are placed in contact with tissue of the additional compartment, and 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; and (c) determining whether the ECG signal is indicative of the AF for the electrodes whose positioning stability has an error less than a given threshold; and wherein the memory is configured to repeat storing the ECG signal indicative of the AF. (20) The system of embodiment 19, wherein the tissue is located at a first location within the heart and the additional compartment is located at a second location within the heart that is different from the first location, and the processor is configured to set (i) the predetermined time interval and (ii) a duration similar to the given time interval.

Claims

1. 1. A system comprising:

1. A processor comprising: receiving, for each electrode of a catheter having a plurality of electrodes placed in contact with tissue of a patient's heart during a predetermined 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 predetermined time interval based on the position signal; a processor configured to determine whether the ECG signal is indicative of atrial fibrillation (AF) in the heart for the electrodes having a positioning stability error less than a given threshold; a memory configured to store the ECG signal indicative of the AF.

2. 2. The system of claim 1, wherein the processor is configured to store in the memory: (i) a first set of the ECG signals calculated at a first attribute indicative of the AF; and (ii) a second set of the ECG signals calculated at a second attribute indicative of the AF, the second attribute being different from the first set.

3. The system of claim 2 , comprising a display configured to display the stored ECG signals on one or more maps of the heart.

4. 4. The system of claim 3, wherein the processor is configured to (i) assign a first graphical representation to the first set of ECG signals and the first attribute, and (ii) assign a second graphical representation to the second set of ECG signals and the second attribute, and wherein the display is configured to display one or both of (i) the first and second sets, and (ii) the first and second attributes, on the one map of the heart.

5. 4. The system of claim 3, wherein the processor is configured to (i) assign a first graphical representation to the first set of ECG signals and the first attributes, and (ii) assign a second graphical representation to the second set of ECG signals and the second attributes, and the display is configured to (i) display one or both of the first set and the first attributes on a first map of the heart, and (ii) display one or both of the second set and the second attributes on a second map of the heart that is different from the first map.

6. The system of claim 2 , wherein the first attribute comprises a topographical point and the second attribute comprises an atrial fibrillation cycle length (ACLV) slope.

7. 2. The system of claim 1, wherein the processor is configured to calculate the positioning stability for each of the electrodes by: (i) maintaining the given threshold indicative of the positioning stability; (ii) calculating a standard deviation (SD) of the position signal for each of the electrodes using the position signals received from each of the electrodes along the predetermined time interval; and (iii) comparing the calculated SD of each of the electrodes with the given threshold.

8. 2. The system of claim 1, wherein the electrodes of the catheter are arranged in an array to cover a selected segment of the heart, and the processor is configured to select the predetermined time interval by selecting a duration of the predetermined time interval between 1 second and 10 seconds.

9. 9. The system of claim 8, wherein the array of electrodes is moved to an additional compartment of the heart and the electrodes are placed in contact with tissue of the additional compartment, and 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; and (c) determining whether the ECG signal is indicative of the AF for the electrodes whose positioning stability has an error less than a given threshold; and wherein the memory is configured to repeat storing the ECG signal indicative of the AF.

10. 10. The system of claim 9, wherein the tissue is located at a first location within the heart and the additional compartment is located at a second location within the heart that is different from the first location, and the processor is configured to: (i) set the predetermined time interval; and (ii) set a duration similar to the given time interval.

11. 1. A method comprising: inserting a catheter having a plurality of electrodes into a patient's heart and placing the electrodes in contact with tissue of the heart; receiving, for each of the electrodes, during a predetermined 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 predetermined time interval based on the position signals; For the electrodes having a positioning stability error less than a given threshold, determining whether the ECG signal is indicative of atrial fibrillation (AF) in the heart; and storing the ECG signal indicative of the AF.

12. 12. The method of claim 11, wherein storing the ECG signals indicative of the AF comprises storing (i) a first set of the ECG signals calculated under a first attribute indicative of the AF, and (ii) a second set of the ECG signals calculated under a second attribute indicative of the AF, the second attribute being different from the first attribute.

13. 13. The method of claim 12, comprising displaying the stored ECG signals on one or more maps of the heart.

14. 14. The method of claim 13, wherein displaying the stored ECG signals on a map of the heart comprises: (a) (i) assigning a first graphical representation to the first set of ECG signals and the first attribute, and (ii) assigning a second graphical representation to the second set of ECG signals and the second attribute; and (b) displaying one or both of (i) the first set and the second set, and (ii) the first attribute and the second attribute, on the map of the heart.

15. 14. The method of claim 13, wherein displaying the stored ECG signals on a plurality of maps comprises: (a) (i) assigning a first graphical representation to the first set of ECG signals and the first attribute, and (ii) assigning a second graphical representation to the second set of ECG signals and the second attribute; and (b) (i) displaying one or both of the first set and the first attribute on a first map of the heart, and (ii) displaying 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 method of claim 12 , wherein the first attribute comprises a topographical point and the second attribute comprises a gradient of an atrial fibrillation cycle length (ACLV).

17. 12. The method of claim 11, wherein calculating the positioning stability comprises, for each of the electrodes: (i) maintaining the given threshold indicative of the positioning stability; (ii) calculating a standard deviation (SD) of the location signals for each of the electrodes using the location signals received from each of the electrodes along the predetermined time interval; and (iii) comparing the calculated SD of each of the electrodes with the given threshold.

18. 12. The method of claim 11, wherein placing the electrodes in contact with tissue of the heart includes placing an array of the electrodes to cover selected segments of the heart, and wherein the predetermined time interval includes selecting a duration of the predetermined time interval between 1 second and 10 seconds.

19. 20. The method of claim 18, comprising: moving the array of electrodes to additional compartments of the heart and placing the electrodes in contact with tissue of the additional compartments; and repeating the following: (a) receiving the position signals and the ECG signals 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) for the electrodes whose positioning stability has an error less than a given threshold, determining whether the ECG signals are indicative of the AF; and (d) storing the ECG signals indicative of the AF.

20. 20. The method of claim 19, wherein the tissue is located at a first location within the heart and the additional compartment is located at a second location within the heart that is different from the first location, and the predetermined time interval and the given time interval have similar durations.

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