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

• US 8,401,644 B2
• Filed: 11/28/2006
• Issued: 03/19/2013
• Est. Priority Date: 11/28/2005
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Gunderson, Bruce D., Brown, Mark L., Patel, Amisha Somabhai
• Primary Examiner(s): Holmes, Rex R
• Application Number:
  US11/564,139
• Publication Number:
  US 20070135863A1
• Time in Patent Office: 2,303 Days
• Field of Search: 607/9, 607 27- 29, 600509-514
• US Class Current: 607/27
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/35 by template matching
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61N 1/368 comprising more than one electrode co-operating with different heart regions A61N1/3622, A61N1/3627 take precedence

Abstract

A method and system of 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 there is an abrupt onset of the cardiac event in response to the transmitted data.

Claims

1. A method of post-processing 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 sensing data, instances where the implantable medical device identified a cardiac event being detected in response to the sensing data;

determining a first median of a first set of ventricular sensed event to ventricular sensed event intervals of the received sensing data, wherein the first set of intervals includes sensing data occurring just prior to the cardiac event being detected, and wherein the sensing data occurring just prior to the cardiac event being detected includes one or more ventricular sensed event to ventricular sensed event intervals associated with the cardiac event being detected;

determining a second median of a second set of ventricular sensed event to ventricular sensed event intervals of the received sensing data, wherein the second set of intervals includes sensing data occurring prior to a number of intervals associated with the cardiac event being detected, and wherein the second set of intervals does not include the one or more ventricular sensed event to ventricular sensed event intervals associated with the cardiac event being detected; and

determining, with the external access device, whether there is an abrupt onset of the cardiac event in response to determining that a difference between the first median and the second median is greater than a predetermined threshold.

2. The method of claim 1, wherein the predetermined threshold is 60 ms.

5. The method of claim 1, further comprising:

determining, with the external access device, a ratio of sensed atrial events to sensed ventricular events in response to the received sensing data; and

determining, with the external access device, whether there is an abrupt onset of the cardiac event in response to the sensed atrial events not being evenly distributed with the sensed ventricular events.

3. 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, the sensing data including sensed atrial events and sensed ventricular events;

an access device located externally from the implantable 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, in response to the received data, instances where the implantable medical device identified a cardiac event as being detected in response to the sensing data, determines a first median of a first set of ventricular sensed event to ventricular sensed event intervals of the received sensing data, wherein the first set of intervals includes sensing data occurring just prior to the cardiac event being detected, and wherein the sensing data occurring just prior to the cardiac event being detected includes one or more ventricular sensed event to ventricular sensed event intervals associated with the cardiac event being detected, determines a second median of a second set of ventricular sensed event to ventricular sensed event intervals of the received sensing data, wherein the second set of intervals includes sensing data occurring prior to a number of intervals associated with the cardiac event being detected, and wherein the second set of intervals does not include the one or more ventricular sensed event to ventricular sensed event intervals associated with the cardiac event being detected, determines a difference between the first median and the second median, and determines whether there is an abrupt onset of the cardiac event in response to the difference between the first median and the second median being greater than a predetermined threshold.

4. The system of claim 3, wherein the predetermined threshold is 60 ms.

6. The system of claim 3, wherein the external device determines a ratio of sensed atrial events and sensed ventricular events in response to the received sensing data, and, in response to the sensed atrial events not being evenly distributed with the sensed ventricular events.