Matching and tracking time sequences of heart activation

Abstract

A method, including, receiving a first group of electrocardiograph (ECG) signals derived from a single heartbeat and generated at a respective plurality of electrodes on a catheter in a heart of a subject, formulating a template relating times of annotations of the first group of the ECG signals, and assigning the template an index. The method further includes receiving a second group of ECG signals derived from a subsequent single heartbeat and generated at the electrodes, calculating times of annotations of the second group, formulating a comparison between the template and the times of annotations of the second group, and, when the comparison indicates that the times of annotations of the second group correspond to the template, assigning the index to the second group of ECG signals, and presenting graphically on a display an occurrence of the template relative to a timeline representing heartbeats from the heart.

What is claimed is: 
     
         1 . A method, comprising:
 providing a template with a first time pattern;   receiving a second group of ECG signals derived from a single heartbeat and generated at a plurality of electrodes;   calculating times of annotations of the second group of ECG signals with a second time pattern relating the times of annotations of the second group;   formulating a comparison of similarity between the first time pattern and the second time pattern, the second time pattern being based on a difference between the annotation of each ECG signal of the second group and a weighted average of the time of annotations of the second group; and   when the comparison indicates that the times of annotations of the second group correspond to the template within a preset threshold, presenting graphically on a display an occurrence of the template relative to a timeline representing the single heartbeat.   
     
     
         2 . The method of  claim 1 , further comprising:
 when the comparison indicates that the times of annotations of the second group correspond to the template outside of a preset threshold, receiving a third group of ECG signals derived from a subsequent single heartbeat and generated at the plurality of electrodes.   
     
     
         3 . The method of  claim 1  further comprising:
 wherein the providing a template includes assigning the template with an index; and 
 assigning the index to the second group of ECG signals when the comparison indicates that the times of annotations of the second group correspond to the template within a preset threshold. 
 
     
     
         4 . The method of  claim 1 , wherein the preset threshold ranges between about 0.5 and 1.2. 
     
     
         5 . The method of  claim 1 , wherein the receiving a second group of ECG signals derived from a subsequent single heartbeat and generated at the plurality of electrodes occurs within a window of interest time interval. 
     
     
         6 . The method of  claim 1 , wherein the calculating times of annotations of the second group of ECG signals with a second time pattern relating the times of annotations of the second group occurs continually. 
     
     
         7 . The method of  claim 1 , further comprising when the comparison indicates that the times of annotations of the second group correspond to the template within a preset threshold, storing the times of annotations of the second group in a buffer 
     
     
         8 . The method of  claim 1 , wherein the template is preset. 
     
     
         9 . The method of  claim 1 , wherein the template is based on a user's selection. 
     
     
         10 . The method of  claim 1 , wherein the plurality of electrodes is located on a catheter configured to be positioned in the coronary sinus of a heart. 
     
     
         11 . An apparatus, comprising:
 a catheter located in a heart of a subject and carrying a plurality of electrodes configured to sense a group of ECG signals derived from a single heartbeat of the subject; and
 a processor configured to:
 provide a template with one time pattern; 
 receive the group of ECG; 
 calculate times of annotations of the group of ECG signals with another time pattern relating the times of annotations of the group; 
 formulate a comparison of similarity between the one time pattern and other time pattern, the other time pattern being based on a difference between the annotation of each ECG signal of the group and a weighted average of the time of annotations of the group; and 
 when the comparison indicates that the times of annotations of the group correspond to the template within a preset threshold, present graphically on a display an occurrence of the template relative to a timeline representing the single heartbeat. 
 
   
     
     
         12 . The apparatus of  claim 11 , wherein the processor is further configured to:
 when the comparison indicates that the times of annotations of the group correspond to the template outside of a preset threshold, receive yet another group of ECG signals derived from a subsequent single heartbeat and generated at the plurality of electrodes.   
     
     
         13 . The apparatus of  claim 11 , wherein the processor is further configured to:
 assign the template with an index when the processor provides a template; and   assign the index to the group of ECG signals when the comparison indicates that the times of annotations of the group correspond to the template within a preset threshold.   
     
     
         14 . The apparatus of  claim 11 , wherein the preset threshold ranges between about 0.5 and 1.2. 
     
     
         15 . The apparatus of  claim 11 , wherein the processor is configured to:
 within a window of interest time interval, receive a group of ECG signals derived from a subsequent single heartbeat and generated at the plurality of electrodes.   
     
     
         16 . The apparatus of  claim 11 , wherein the processor is configured to continually calculate the times of annotations of the group of ECG signals with the time pattern relating the times of annotations of the group. 
     
     
         17 . The apparatus of  claim 11 , wherein the processor is configured to store the times of annotations of the group in a buffer when the comparison indicates that the times of annotations of the second group correspond to the template within a preset threshold. 
     
     
         18 . The apparatus of  claim 11 , wherein the template is preset. 
     
     
         19 . The apparatus of  claim 11 , wherein the template is based on a user's selection. 
     
     
         20 . The apparatus of  claim 11 , wherein the plurality of electrodes is located on a catheter configured to be positioned in the coronary sinus of a heart.