US-20260123875-A1 - FINDING A CARDIAC LINE OF BLOCK USING STATISTICAL ANALYSIS OF ACTIVATION WAVE VELOCITY

Abstract

A method includes receiving a set of data points including positions and respective velocities of an activation wave in a tissue region of a cardiac chamber. The set is partitioned into at least two velocity clusters, each velocity cluster characterized by a respective velocity of the activation wave. One or more border curves are estimated, between the at least two clusters. The one or more border curves are indicated to a user as possible lines of block of the activation wave.

Inventors

• Assaf Govari
• Vadim Gliner
• Andres Claudio Altmann

Assignees

• BIOSENSE WEBSTER (ISRAEL) LTD.

Dates

Publication Date

20260507

Application Date

20251229

Claims (9)

1. 1 - 16 . (canceled)
2. 17 . A method for finding a cardiac blocking line during an electrophysiological (EP) procedure, comprising: delivering ablation energy from a generator to an ablation device, while the ablation device is placed in a cardiac chamber of a patient; acquiring, by at least one electrode while placed in the cardiac chamber of the patient, a set of data points comprising positions and respective velocities of an activation wave in a tissue region of the cardiac chamber; partitioning the set into at least two velocity clusters, each velocity cluster characterized by a respective velocity of the activation wave, the partitioning comprises applying a k-means clustering process, the partitioning being iterative; calculating the mean of the velocities, as well as the variance of the mean, at each iteration of the partitioning; estimating one or more border curves between the at least two clusters of data points by identifying a discontinuity in the velocities between different clusters; constructing, by a processor, an EP map of the cardiac chamber based on the set of data points acquired by the at least one electrode; displaying to a user, on a display device, the EP map, the EP map including a representation of the tissue region; and indicating to the user, on the EP map, the one or more border curves as possible lines of block of the activation wave wherein the indicating is based on a discontinuity line in wave velocities and is configured to assist in cardiac ablation efficacy estimation.
3. 18 . The method according to claim 17 , wherein indicating to a user comprises overlaying the one or more border curves on the EP map.
4. 19 . The method according to claim 18 , wherein the EP map is at least part of an activation wave velocity map.
5. 20 . The method according to claim 18 , and comprising overlaying activation times on the EP map.
6. 21 . A system for finding a cardiac blocking line during an electrophysiological (EP) procedure, comprising: at least one electrode configured to be inserted into a cardiac chamber of a patient, the at least one electrode configured to acquire velocities of an activation wave in a tissue region of the cardiac chamber, after the tissue region has been ablated; an interface configured to acquire, by the at least one electrode, a set of data points comprising positions and respective velocities of an activation wave in the tissue region of a cardiac chamber; and a processor, which is configured to: partition the set into at least two velocity clusters, by applying a k-means clustering process, each velocity cluster characterized by a respective velocity of the activation wave, the partitioning being iterative; calculate the mean of the velocities, as well as the variance of the mean, at each iteration of the partitioning; estimate one or more border curves between the at least two clusters of data points, by identifying a discontinuity in the velocities between different clusters; construct an EP map of the cardiac chamber based on the set of data points acquired by the at least one electrode; display to a user, on a display device, the EP map, the EP map including a representation of the tissue region; and indicate to the user, on the EP map, the one or more border curves as possible lines of block of the activation wave, the indicating is based on a discontinuity line in wave velocities and, the indicating is configured to assist in cardiac ablation efficacy estimation.
7. 22 . The system according to claim 21 , wherein the processor is configured to indicate the one or more border curves to a user by overlaying the one or more border curves on the EP map.
8. 23 . The system according to claim 22 , wherein the EP map is at least part of an activation wave velocity map.
9. 24 . The system according to claim 22 , wherein the processor is further configured to overlay activation times on the EP map.

Description

FIELD OF THE INVENTION The present invention relates generally to electrophysiological (EP) mapping, and particularly to analysis of cardiac EP maps. BACKGROUND OF THE INVENTION Methods for assisting the analysis of electrophysiologically mapped cardiac tissue were previously proposed in the patent literature. For example, U.S. Patent Application Publication No. 2021/0093217 describes a method for generating propagation and velocity maps for cardiac wavefront propagation including cardiac arrhythmia, sinus rhythm, and paced rhythm. Activation time information is generated in the absence of any time alignment reference, wherein an estimated activation time is a weighted summation of potentially nonlinear and nonorthogonal candidate functions (CFs) selected from a bank of CFs. Time alignments between sequential recordings may be done by including binary level functions among selected CFs. Embodiments are applicable to single catheter mapping and sequential mapping, and are robust as confirmed by the ability to generate propagation maps and conduction velocity in the presence of multiple colliding wavefronts. The propagation and conduction velocity maps may be used for one or more of diagnosing cardiac arrhythmia, localizing cardiac arrhythmia, guiding catheter ablation therapy of cardiac arrhythmia, and guiding cardiac pacing therapy. As another example, U.S. Patent Application Publication No. 2004/0176697 describes an analysis of electrocardiograms (ECGs) during atrial fibrillation. In particular, the invention relates to the use of such methods for the creation and validation of cardiac models and use in the refined diagnosis of heart disease. Classification of the atrial fibrillation of a given patient or group of patients is performed using an auto regressive (AR) model coefficients subjected to a mathematical cluster analysis, including hierarchical methods (e.g., single linkage, average linkage (weighted and unweighted), centroid, median and complete linkage) and non-hierarchical methods (e.g., the k-means clustering algorithm, adaptive k-means, k-medoids, and fuzzy clustering). SUMMARY OF THE INVENTION An embodiment of the present invention provides a method including receiving a set of data points including positions and respective velocities of an activation wave in a tissue region of a cardiac chamber. The set is partitioned into at least two velocity clusters, each velocity cluster characterized by a respective velocity of the activation wave. One or more border curves are estimated, between the at least two clusters. The one or more border curves are indicated to a user as possible lines of block of the activation wave. In some embodiments, partitioning the set includes applying a k-means clustering process. In some embodiments, partitioning the set includes partitioning the set based on magnitudes of the velocities. In other embodiments, partitioning the set includes partitioning the set based on directions of the velocities. In an embodiment, estimating the border curves includes identifying a discontinuity in the velocities between different clusters. In another embodiment, indicating the one or more border curves to a user includes overlaying the one or more border curves on a surface representation of the cardiac chamber. In some embodiments, the surface representation is at least part of an activation wave velocity map. In some embodiments, the method further includes overlaying activation times on the surface representation. There is additionally provided, in accordance with an embodiment of the present invention, a system including an interface and a processor. The interface is configured to receive a set of data points including positions and respective velocities of an activation wave in a tissue region of a cardiac chamber. The processor is configured to (i) partition the set into at least two velocity clusters, each velocity cluster characterized by a respective velocity of the activation wave, (ii) estimate one or more border curves between the at least two clusters, and (iii) indicate the one or more border curves to a user as possible lines of block of the activation wave. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more fully understood from the following detailed description of the embodiments thereof, taken together with the drawings in which: FIG. 1 is a schematic, pictorial illustration of a system for electrophysiological (EP) mapping and ablation, in accordance with an exemplary embodiment of the present invention; FIG. 2 is a schematic plot showing a use of the k-means method to identify discontinuity in activation speeds and to identify a blocking line of an activation wave, in accordance with an exemplary embodiment of the present invention; FIG. 3 is a schematic, pictorial illustration of an activation wave velocity map showing a blocking line of an activation wave overlaid on a surface representation of a left ventricle, in accordance with an exemplar