Smart Cardiac Electrophysiological (EP) Maps

Abstract

A system for generating an electrophysiological (EP) map includes a display and a processor configured to (i) receive a plurality of EP data points, including respective locations and EP values, generated from signals acquired by one or more electrodes of a catheter in contact with tissue of a cardiac chamber, (ii) score the received data points with respective quality scores, (iii) for a given unit volume of the EP map, select from among the data points whose locations are within the unit volume a data point having a highest quality score for use in generating the EP map, and (iv) visualize the EP map to a user on the display.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 317,117, filed March 7, 2022, which is incorporated herein by reference.

[0002] FIELD OF THEINVENTION The present disclosure relates generally to cardiac electrophysiological (EP) mapping, and more particularly to automating the generation of data points for cardiac EP maps. [Background technology]

[0003] Automated processing of catheter-acquired EP signals has been described in the patent literature. For example, US Patent Application Publication No. 2009 / 0099468 describes a method, apparatus, and computer program product for automated processing of intracardiac electrophysiological data. The method includes the steps of recording electrogram data and corresponding spatial location data of electrodes recording the electrogram data, where the recorded electrogram data includes a plurality of beats, defining at least one reference channel including a reference beat for determining a temporal location and for which the beats of the recorded electrogram data are compared, observing the recorded electrogram data and defining a temporal location for each beat of the recorded electrogram data, creating an index of the temporal location and other information of the beats in the recorded electrogram data, analyzing in real time at least one electrophysiological feature of the recorded electrogram data indicative of a physiological condition, and providing an updated index, where the other information includes the analysis results.

[0004] As another example, U.S. Patent No. 10,376,221 describes the automated creation of multiple electroanatomical maps. Electrograms of the heart are recorded on multiple channels. Beats are automatically classified into corresponding classes according to the similarity of the morphological features of the beats to the members of a template set. Corresponding electroanatomical maps of the heart are generated from the classified beats.

[0005] 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: [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic, depiction of a system for electrophysiological (EP) mapping and ablation, according to an example of the present disclosure. [Diagram 2] 1 is a flow chart that generally illustrates a method for considering candidate data points based on automatic quality scoring of the data points, according to an example of the present disclosure. [Diagram 3] 2 is a schematic diagram of a graphical user interface (GUI) of the electrophysiological (EP) mapping system of FIG. 1 including a scale for setting a quality scoring threshold, according to an example of the present disclosure; FIG. [Figure 4] FIG. 3 is a schematic diagram of an information layer of an EP map according to an example of the present disclosure, the layer spatially indicating EP map quality according to the quality scores of data points automatically accepted by the process of FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] overview Probe-based (e.g., catheter-based) cardiac diagnostic and therapeutic systems may measure multiple intracardiac electrophysiological (EP) signals, such as electrocardiograms (EGMs), during invasive procedures. Such systems acquire multiple intracardiac signals using one or more electrodes (e.g., multiple electrodes) attached to the distal end of a probe. For example, to reduce the time required to EP map a heart chamber, a catheter carrying a large number of electrodes (e.g., 256), such as a basket catheter, may be used to acquire EGM signals of the heart chamber. Often, analysis of a large number of such EP signals acquired in parallel is performed to generate data points that are used to generate an EP map, e.g., in a continuous mode (automatically), in order to enable processing of such large amounts of EP information.

[0008] The generation of data points typically involves applying rejection criteria (e.g., the use of "filtering" to avoid using "false" data points, such as those that are irrelevant or too noisy, at any given time). Thus, the physician performing the procedure needs to set "appropriate" filtering criteria and monitor the filtering process to ensure that the settings generate data points of sufficient quality (e.g., relevant, stable) (e.g., for an EP map).

[0009] Thus, acquired data points are typically subjected to filtering (e.g., rejection criteria) to remove data points that may be inaccurate (e.g., unstable) or irrelevant (e.g., acquired from the blood pool instead of the ventricular surface). When acquired data points are subjected to multiple filters, each with an individual threshold, if a point fails to pass any one filter, it is rejected all things considered, even if it may be acceptable if not of high quality. When the total number of data points acquired during an EP mapping session is large, reaching tens of thousands with modern multi-electrode mapping catheters, it is difficult for a physician to determine whether the filter setting level is appropriate, e.g., whether too many or too few data points are being rejected. Furthermore, with conventional maps, once a data point is acquired, it becomes "permanent" and there is no ability to replace it with a higher quality point, thus preventing the map from reaching the highest potential quality achievable within the acquireable data.

[0010] Examples of the disclosure described herein provide algorithms and visualizations for high-level (e.g., based primarily on clinical input) and automatic data point selection, for example, to generate and update EP maps in real time. In some examples, each newly received data point is scored by a processor using a disclosed quality score. The disclosed algorithm (called SMARTMAP) prioritizes the scores of high quality data points over low quality data points when constructing (e.g., visualizing) an EP map by swapping data point selection according to their quality scores. To this end, the processor is configured to replace a previously selected data point with the newly acquired data point in response to finding that the quality score of the newly acquired data point in a given unit volume is higher than the quality score of a previously selected data point in a given unit volume, as defined below.

[0011] The aforementioned quality score of a data point, also referred to herein as a "smart index," is the output of a weighting function that considers several data point parameters acquired during a pre-processing stage (e.g., annotation) of the intracardiac waveform. The weighted parameters include, for example, cycle length, signal amplitude, stability of local activation time (LAT), electrode stability, and level of contact with tissue during acquisition, among others, as described below. In some examples, the processor evaluates each new data point with a normalized quality score ranging from 0 to 1.

[0012] In some examples, the process of data point selection and EP map updating with newly selected data points occurs in real-time while continuous acquisition is ongoing. The disclosed SmartMap technique reduces the physician's workload (i.e., user workflow) by eliminating the data point filtering step, which results in simpler and faster data point acquisition and quicker EP map setup. Thus, user involvement and decision making is limited to high-level settings such as arrhythmia type and quality score thresholds, all performed via a high-level GUI.

[0013] One example of a high-level visualization provided includes a layer of the EP map, sometimes called a "heat map," that spatially indicates EP map quality according to the quality scores (i.e., "smart index") of the graded data points. This layer guides the physician by graphically indicating regions of the ventricle for mapping catheter insertion. If the amount of data points is too small (e.g., spatially sparse), the physician can collect additional data points to improve the EP map quality in such regions. Another high-level visualization is an adjustable scale for the aforementioned user-selected threshold of quality score, so that the user can fine-tune the EP map quality by changing the quality scoring threshold below which candidate data points are not considered.

[0014] System Description FIGURE 1 is a schematic depiction of a system 21 for electrophysiological (EP) mapping and ablation, according to one example of the present disclosure. FIGURE 1 illustrates a physician 27 using an EP mapping catheter 29 to perform EP mapping of a heart 23 of a patient 25. The catheter 29 comprises, at its distal end, a multi-channel electrode array 50 comprising one or more arms 20 each coupled to a mapping electrode 22. During a mapping procedure, the electrodes 22 acquire signals from and / or inject signals into tissue of the heart 23. In particular, the electrodes 22 acquire intracardiac EP signals, such as unipolar and / or bipolar electrograms (e.g., electrograms 40 shown on a display 26 of the system 21).

[0015] Catheter 29 can further be used to perform ablation, such as radio frequency (RF) or irreversible electroporation (IRE).

[0016] The location of each of the mapping electrodes 22 within the heart 23 (i.e., where the electrograms are measured) is also tracked so that the processor 28 can associate each acquired electrogram with the location where the signal was acquired to generate, for example, an EP map data point. The system 21 senses the electrical position signals externally using a number of external electrodes 24 attached to the body of the patient 25. For example, three external electrodes 24 may be attached to the patient's chest and another three external electrodes may be attached to the patient's back. For ease of illustration, only one external electrode is shown in FIG. 1.

[0017] One example of a system that can be used to track the position of the mapping electrodes 22 within the patient's heart 23 using sensed electrical position signals is the CARTO® 3 system (manufactured by Biosense Webster, Irvine, California). The CARTO® 3 system uses a tracking method known as Advanced Current Location (ACL), which is described in detail in U.S. Patent No. 8,456,182, which is incorporated herein by reference.

[0018] The data acquisition module 33 receives a plurality of electrogram signals that are transmitted to the electrical interface 35 via a conductor link installed within the catheter 29. The processor 28 of the system 21 receives these cardiac signals via the electrical interface 35, processes them into data points, and then uses the disclosed algorithms to classify the data points based on different predefined arrhythmia types, such as, for example, atrial fibrillation, tachycardia, flutter, etc. In this manner, the physician 27 does not need to navigate a menu of data filters to determine the suitability of acquired data points for use in an EP map. It should be noted that the algorithms disclosed herein represent only some exemplary algorithms of many that may be used within the scope of the appended claims.

[0019] Processor 28 also stores the acquired data points in memory 31 for further analysis, such as constructing an EP map. One example of an EP map that may be generated by processor 38 from the automatically classified data points is a local activation time (LAT) map. A method for generating a LAT map is described in U.S. Patent No. 9,050,011, assigned to the assignee of the present application.

[0020] Processor 28 typically comprises a general-purpose computer with software programmed to perform the functions described herein. The software may be downloaded to the computer in electronic form, for example over a network, or alternatively or additionally may be provided and / or stored on a non-transitory tangible medium, such as magnetic, optical, or electronic memory. In particular, processor 28 executes dedicated algorithms that enable processor 28 to perform each of the steps described in FIG.

[0021] The exemplary illustration shown in Figure 1 has been selected solely for conceptual clarity. Other types of multi-electrode sensing configurations may also be used, such as the multi-electrode sensing configuration of the Lasso® catheter (Biosense Webster) or basket catheter. In addition, a contact sensor may be attached to the distal end of the electroanatomic catheter 29 to transmit data indicative of the physical quality of electrode contact with tissue.

[0022] Method for automatic quality scoring of data points 2 is a flow chart that generally illustrates an exemplary method for considering (i.e., rejecting or accepting) candidate data points based on automatic quality scoring of the data points, according to one example of the present disclosure. The algorithm according to the presented example executes a process that begins with the processor 28 receiving (e.g., uploading) new data points in a receive new data points step 202. The received data points are aggregated by the processor (e.g., stored in memory 31) as part of a point cloud that can be used in generating an EP map or for other applications.

[0023] In a quality score calculation step 204, processor 28 calculates a quality score for the data point according to Equation 1 below:

[0024] Processor 28 then compares the calculated quality score to a user set quality score threshold in a comparison step 206. If the calculated quality score is below the threshold, processor 28 rejects the new data point in a data point rejection step 208.

[0025] If the calculated quality score is higher than the threshold, processor 28 checks, in a data point presence check step 210, whether a unit volume of a predetermined size (e.g. a sphere of a predetermined radius, such as 1 mm) containing the newly received data point is occupied by one or more existing data points.

[0026] If the answer is no, ie, the newly received data point is the only data point within the given unit volume, processor 28 accepts the data point in a data point acceptance step 212 .

[0027] If the answer is yes, processor 28 checks, in a quality score value comparison step 314, whether the quality score of the newly received data point is higher than the quality scores of the existing data points within the unit volume.

[0028] If the answer is no, processor 28 rejects the new data point in a data point rejection step 316. If the answer is yes, processor 28 accepts the data point in a data point acceptance step 312. The accepted data point (from either step 212 or step 218) may be used by the processor to update an existing EP map.

[0029] Quality score of data points in SMARTMAP As mentioned above, the smart index is the result of a weighting function that weights several parameters of a data point, for example as listed below in Table I. Each candidate data point is scored with a normalized score (also called the smart index) that ranges from 0 to 1.

[0030] An exemplary formula for the data point smart index is:

[0031]

number

[0032] [Table 1]

[0033] In Table I, complex split atrial electrograms (CFAE) and late activation mapping (LAM) show complex EP signal behavior, such as that from scar tissue regions. This deserves attention from clinicians, and this distinction may therefore receive high weighting for at least some arrhythmias.

[0034] In Table I, pattern matching is a test of the consistency of data points over cardiac cycles (inter-cardiac cycle correlation values).

[0035] CL represents the cardiac cycle length.

[0036] TPI stands for Touch Pressure Index (or Contact Pressure Index), which estimates the contact force of the catheter electrode with the tissue wall during acquisition of a data point.

[0037] Positional stability is a measure of the consistency of electrode position during an acquisition over two or more cardiac cycles.

[0038] The respiration weighting adversely affects respiration during acquisition, such as introducing noise into the signal.

[0039] Position CPM is a measure of the previously described ACL position tracking technique regarding the consistency of electrode position during acquisition.

[0040] SNR stands for signal-to-noise ratio, which, when low, indicates a less robust acquisition.

[0041]

number

[0042] Table I is provided for illustrative purposes only, other parameter lists may vary.

[0043] Graphical user interface tool for SMARTMAP FIG. 3 is a schematic diagram of a graphical user interface (GUI) 300 of the electrophysiological (EP) mapping system 21 of FIG. 1 according to one example of the present disclosure, where the GUI 300 includes a scale 302 for setting a quality scoring threshold.

[0044] The GUI 300 further includes a status bar 304 on the level of the pattern matching correlation results. A low value may indicate suboptimal acquisition conditions, which may suggest to the physician the need to improve the acquisition conditions to generate more meaningful EP data.

[0045] The TPI checkbox 306 allows the user to include TPI weighting, which is a time-consuming step in the process of accepting data points, for example to update an EP map.

[0046] Finally, area 308 presents the active EP map through which the user can toggle to adjust thresholds, for example according to map type or arrhythmia type in question.

[0047] 3 is an example provided solely for illustrative purposes: an actual GUI will typically be much more elaborate and will include, for example, numerous icons and graphics that are omitted here for simplicity of presentation.

[0048] Figure 4 is a schematic diagram of an information layer 400 of an EP map according to one example of the present disclosure, which spatially indicates the quality of the EP map according to the quality scores of the data points automatically accepted by the process of Figure 2. The map shown depicts the left ventricular anatomy 402 that has been EP mapped with a catheter.

[0049] A scale 408 indicates to the user the quality scores of the data points in different regions of the mapped anatomy 402. As shown, some regions (404) have not yet been mapped. Some regions (e.g., highlighted region 405) have been mapped with various intermediate quality score levels of data points. Finally, some regions, such as region 406, are mapped with data points of high quality scores. Using layer 400, which is a type of heat map of quality scores of accepted and used data points, the physician performing EP mapping can use to direct the catheter to areas where EP map quality can be improved. EXAMPLES

[0050] Example 1 A system (21) for generating an electrophysiological (EP) map includes a display (26) and a processor (28) configured to (i) receive a plurality of EP data points, including respective positions and EP values, generated from signals (40) acquired by one or more electrodes (22) of a catheter (29) in contact with tissue of a cardiac chamber, (ii) score the received data points with respective quality scores, (iii) for a given unit volume of the EP map, select from among the data points whose positions are within the unit volume the data point having the highest quality score for use in generating the EP map, and (iv) visualize the EP map to a user on the display (26).

[0051] Example 2 The system of example 1, wherein the processor (28) is configured to adjust the quality score according to a type of arrhythmia selected by a user.

[0052] Example 3 The system of any of Examples 1 and 2, wherein the quality score comprises a weighted scoring of at least two of: (i) pattern matching of the signal (40); (ii) annotated cycle length; (iii) LAT stability; (iv) complex / simple data point flagging; (v) electrode contact pressure index; (vi) electrode position stability; (vii) respiratory flux; and (vii) signal SNR; and (viii) sharpness of signal deflection.

[0053] Example 4 The system of any of Examples 1 to 3, wherein the processor (28) is configured to, in response to finding that a quality score of the newly acquired data point within the given unit volume is higher than a quality score of a previously selected data point for the given unit volume, replace the previously selected data point with the newly acquired data point.

[0054] Example 5 The system of any of Examples 1 to 4, wherein the processor (28) is further configured to generate a layer of the EP map spatially indicating the quality of the EP map according to the quality scores of the received selected data points and present it to the user on the display (26).

[0055] Example 6 The system of any of Examples 1 to 5, wherein the processor (28) is further configured to display a graphical user interface (GUI) that enables a user to set a quality score threshold and reject any data points whose quality score falls below the threshold.

[0056] Example 7 A method for generating an electrophysiological (EP) map, the method comprising receiving a plurality of EP data points, each including a location and an EP value, generated from signals (40) acquired by one or more electrodes (22) of a catheter (29) in contact with tissue of a cardiac chamber. The received data points are scored with a respective quality score. For a given unit volume of the EP map, a data point having a highest quality score is selected from among the data points whose location is within the unit volume for use in generating the EP map. The EP map is visualized to a user on a display (26).

[0057] It will be understood that the above described embodiments are given by way of example, and the present disclosure is not limited to what is particularly shown and described herein above. 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 a person skilled in the art upon reading the foregoing description and that are not disclosed in the prior art. Documents incorporated into this patent application by reference shall be considered as an integral part of this application, provided that, to the extent that any term is defined in these incorporated documents in a manner that is inconsistent with the definition expressly or implicitly made herein, only the definition in this specification shall be considered.

[0058] [Embodiment] (1) A system for generating an electrophysiological (EP) map, comprising: A display and 1. A processor comprising: receiving a plurality of EP data points, each including a location and an EP value, generated from signals acquired by one or more electrodes of a catheter in contact with tissue of the ventricle; Scoring the received data points with a respective quality score; For a given unit volume of the EP map, selecting from among the data points whose locations are within the unit volume a data point having a highest quality score for use in generating the EP map; and a processor configured to visualize the EP map to a user on the display. (2) The system of embodiment 1, wherein the processor is configured to adjust the quality score according to a type of arrhythmia selected by a user. (3) The system of embodiment 1, wherein the quality score comprises a weighted scoring of at least two of: (i) signal pattern matching, (ii) annotated cycle length, (iii) LAT stability, (iv) complex / simple data point flagging, (v) electrode contact pressure index, (vi) electrode position stability, (vii) respiratory flux, (vii) signal SNR, and (viii) signal deflection sharpness. (4) The system of embodiment 1, wherein the processor is configured to, in response to finding that the quality score of a newly acquired data point within the given unit volume is higher than the quality score of a previously selected data point for the given unit volume, replace the previously selected data point with the newly acquired data point. (5) The system of embodiment 1, wherein the processor is further configured to generate a layer of the EP map spatially indicating the quality of the EP map according to the quality scores of the selected data points and present it to the user on the display.

[0059] (6) The system of claim 1, wherein the processor is further configured to display a graphical user interface (GUI) that enables the user to set a quality score threshold and reject any data points whose quality score falls below the threshold. (7) A method for generating an electrophysiological (EP) map, comprising: receiving a plurality of EP data points, each including a location and an EP value, generated from signals acquired by one or more electrodes of a catheter in contact with tissue of the ventricle; scoring the received data points with a respective quality score; for a given unit volume of the EP map, selecting from among the data points whose locations are within the unit volume, a data point having a highest quality score for use in generating the EP map; and visualizing the EP map to a user on a display. (8) The method of embodiment 7, further comprising adjusting the quality score according to a type of arrhythmia selected by a user. (9) The method of embodiment 7, wherein the quality score comprises a weighted scoring of at least two of: (i) signal pattern matching, (ii) annotated cycle length, (iii) LAT stability, (iv) complex / simple data point flagging, (v) electrode contact pressure index, (vi) electrode position stability, (vii) respiratory flux, (vii) signal SNR, and (viii) signal deflection sharpness. (10) The system of embodiment 7, further comprising, in response to finding that the quality score of a newly acquired data point within the given unit volume is higher than the quality score of a previously selected data point for the given unit volume, replacing the previously selected data point with the newly acquired data point.

[0060] (11) The method of embodiment 7, further comprising generating a layer of the EP map that spatially indicates the quality of the EP map according to the quality scores of the selected data points and presenting the layer to the user on the display. (12) The method of embodiment 7, further comprising displaying a graphical user interface (GUI) that enables the user to set a quality score threshold and reject any data points whose quality score falls below the threshold.

Claims

1. 1. A system for generating an electrophysiological (EP) map, comprising: A display and 1. A processor comprising: receiving a plurality of EP data points, each including a position and an EP value, generated from signals acquired by one or more electrodes of a catheter in contact with tissue of the ventricle; Scoring the received data points with a respective quality score; For a given unit volume of the EP map, selecting from among the data points whose locations are within the unit volume a data point having a highest quality score for use in generating the EP map; and a processor configured to visualize the EP map to a user on the display.

2. The system of claim 1 , wherein the processor is configured to adjust the quality score according to a user-selected type of arrhythmia.

3. 2. The system of claim 1, wherein the quality score comprises a weighted scoring of at least two of: (i) signal pattern matching, (ii) annotated cycle length, (iii) LAT stability, (iv) complex / simple data point flagging, (v) electrode contact pressure index, (vi) electrode position stability, (vii) respiratory flux, (vii) signal SNR, and (viii) signal deflection sharpness.

4. 2. The system of claim 1, wherein the processor is configured to, in response to finding that the quality score of a newly acquired data point within the given unit volume is higher than the quality score of a previously selected data point of the given unit volume, replace the previously selected data point with the newly acquired data point.

5. The system of claim 1 , wherein the processor is further configured to generate and present to the user on the display a layer of the EP map that spatially indicates a quality of the EP map according to a quality score of the selected data points.

6. 2. The system of claim 1, wherein the processor is further configured to display a graphical user interface (GUI) that enables the user to set a quality score threshold and reject any data points whose quality score is below the threshold.

7. 1. A method for generating an electrophysiological (EP) map, comprising: receiving a plurality of EP data points, each including a position and an EP value, generated from signals acquired by one or more electrodes of a catheter in contact with tissue of the ventricle; scoring the received data points with a respective quality score; for a given unit volume of the EP map, selecting from among the data points whose locations are within the unit volume a data point having a highest quality score for use in generating the EP map; and visualizing the EP map to a user on a display.

8. The method of claim 7 , comprising adjusting the quality score according to a user-selected type of arrhythmia.

9. 8. The method of claim 7, wherein the quality score comprises a weighted scoring of at least two of: (i) signal pattern matching, (ii) annotated cycle length, (iii) LAT stability, (iv) complex / simple data point flagging, (v) electrode contact pressure index, (vi) electrode position stability, (vii) respiratory flux, (vii) signal SNR, and (viii) signal deflection sharpness.

10. 8. The system of claim 7, further comprising, in response to finding that the quality score of a newly acquired data point within the given unit volume is higher than the quality score of a previously selected data point of the given unit volume, replacing the previously selected data point with the newly acquired data point.

11. The method of claim 7 , further comprising generating a layer of the EP map that spatially indicates a quality of the EP map according to quality scores of the selected data points, and presenting the layer to the user on the display.

12. 8. The method of claim 7, comprising displaying a graphical user interface (GUI) that enables the user to set a quality score threshold and to reject any data points whose quality score falls below the threshold.

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