Method and apparatus for post-processing of episodes detected by a medical device

Abstract

A method and system for determining undersensing during post-processing of sensing data generated by a medical device that includes transmitting a plurality of stored sensing data generated by the medical device to an access device, the stored sensing data including sensed atrial events and sensed ventricular events. The access device determines, in response to the transmitted data, instances where the medical device identified a cardiac event being detected in response to the sensing data, and determines whether one of a predetermined number of undersensing criteria have been met in response to the transmitted data.

1 . A method of determining undersensing during post-processing of sensing data generated by and stored within an implantable medical device, comprising:
 receiving the sensing data from the implantable medical device with an external access device, wherein the sensing data includes sensed atrial events and sensed ventricular events;   determining, with the external access device, in response to the received data, instances where the implantable medical device identified a cardiac event being detected in response to the sensing data; and   determining, with the external access device, whether one of a predetermined number of undersensing criteria have been met in response to the received data, wherein determining whether one of a predetermined number of undersensing criteria have been met comprises calculating a median AA interval in a sliding window of a predetermined number of intervals, and comparing at least one interval within the sliding window to the median AA interval.   
     
     
         2 . The method of  claim 1 , wherein determining whether one of the predetermined number of undersensing criteria have been met further comprises:
 determining whether the median AA interval is greater than a predetermined threshold.   
     
     
         3 . The method of  claim 2 , wherein the predetermined threshold is 1300 milliseconds. 
     
     
         4 . The method of  claim 1 , wherein determining whether one of the predetermined number of undersensing criteria have been met further comprises determining whether the median AA interval is greater than a first predetermined threshold, and a current atrial interval is greater than the median AA interval by a second predetermined threshold. 
     
     
         5 . The method of  claim 4 , wherein the first predetermined threshold is 350 milliseconds and the second predetermined threshold is 1.7 times the median AA interval or more. 
     
     
         6 . The method of  claim 1 , wherein determining whether one of the predetermined number of undersensing criteria have been met further comprises determining whether the median AA interval is within a predetermined range, and a current atrial interval is greater than the median AA interval by a predetermined threshold. 
     
     
         7 . The method of  claim 6 , wherein the predetermined range comprises a range greater than 200 milliseconds and less than or equal to 359 milliseconds, and wherein the predetermined threshold is 1.9 times the median AA interval or more. 
     
     
         8 . The method of  claim 6 , wherein the predetermined range comprises a range greater than 0 milliseconds and less than or equal to 200 milliseconds, and wherein the predetermined threshold is 3.25 times the median AA interval or more. 
     
     
         9 . A system for post-processing of sensing data associated with identification of a cardiac event, comprising:
 an implantable medical device generating and storing a plurality of sensing data, wherein the sensing data includes sensed atrial events and sensed ventricular events;   an access device located externally from the medical device; and   an interface for receiving the sensing data from the implantable medical device with the external access device, wherein the external access device determines whether one of a predetermined number of undersensing criteria have been met in response to the received data, calculates a median AA interval in a sliding window of a predetermined number of intervals, and compares at least one interval within the sliding window to the median AA interval.   
     
     
         10 . The system of  claim 9 , wherein the external access device determines whether the median AA interval is greater than a predetermined threshold. 
     
     
         11 . The system of  claim 10 , wherein the predetermined threshold is 1300 milliseconds. 
     
     
         12 . The system of  claim 9 , wherein the external access device determines whether the median AA interval is greater than a first predetermined threshold, and a current atrial interval is greater than the median AA interval by a second predetermined threshold. 
     
     
         13 . The system of  claim 12 , wherein the first predetermined threshold is 350 milliseconds and the second predetermined threshold is 1.7 times the median AA interval or more. 
     
     
         14 . The system of  claim 9 , wherein the external access device determines whether the median AA interval is within a predetermined range, and whether a current atrial interval is greater than the median AA interval by a predetermined threshold. 
     
     
         15 . The system of  claim 14 , wherein the predetermined range comprises a range greater than 200 milliseconds and less than or equal to 359 milliseconds, and wherein the predetermined threshold is 1.9 times the median AA interval or more. 
     
     
         16 . The system of  claim 14 , wherein the predetermined range comprises a range greater than 0 milliseconds and less than or equal to 200 milliseconds, and wherein the predetermined threshold is 3.25 times the median AA interval or more. 
     
     
         17 . A method of determining undersensing during post-processing of sensing data generated by and stored within an implantable medical device, comprising:
 receiving the sensing data generated by the implantable medical device with an external access device, wherein the sensing data includes sensed atrial events and sensed ventricular events;   determining, with the external access device, in response to the received data, instances where the implantable medical device identified a cardiac event being detected in response to the sensing data; and   determining, with the external access device, whether one of a predetermined number of undersensing criteria have been met in response to the received data, wherein determining whether one of a predetermined number of undersensing criteria have been met comprises determining whether an atrial channel includes less than a predetermined number of events prior to the detection of the cardiac event.   
     
     
         18 . A system for post-processing of sensing data associated with identification of a cardiac event, comprising:
 an implantable medical device generating and storing a plurality of sensing data, wherein the sensing data includes sensed atrial events and sensed ventricular events;   an access device located externally from the medical device; and   an interface for receiving the sensing data from the medical device with the external access device, wherein the external access device determines whether one of a predetermined number of undersensing criteria have been met in response to the received data by at least determining whether an atrial channel includes less than a predetermined number of events prior to the detection of the cardiac event.