System and method for off-line analysis of cardiac data

• US 9,008,760 B2
• Filed: 05/30/2012
• Issued: 04/14/2015
• Est. Priority Date: 05/31/2011
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Dong, Yanting, Zhang, Shijie, Mahajan, Deepa, Liu, Chenguang, Li, Dan, Lin, Yayun, Bohn, Derek D.
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): MAHMOOD, NADIA AHMAD
• Application Number:
  US13/483,394
• Publication Number:
  US 20130138005A1
• Time in Patent Office: 1,049 Days
• Field of Search: 600/508, 600/509
• US Class Current: 600/509
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker
• CPC Class Codes: A61N 1/3704 Circuits specially adapted therefor, e.g. for sensitivity control

Abstract

A system and method for performing off-line analysis of cardiac electrogram data, comprising: retrieving an electrogram from a memory location; identifying a first-channel group of candidate beats from at least a first channel of the electrogram; and identifying a second-channel group of candidate beats from at least a second channel of an electrogram. For each first-channel beat candidate near a second-channel beat candidate, the amplitude of the first-channel beat candidate is compared with the amplitude of a previous beat and the amplitude of a next beat on the first electrogram channel, and first-channel beat candidates that are outside of a first pre-determined range from either the previous or next beat are removed. Then first-channel beat candidates that are outside of a second pre-determined range from either the previous or next beat candidate are removed.

Claims

1. An off-line method for analyzing cardiac electrogram data, comprising:

retrieving an electrogram from a memory location;

identifying a first-channel group of candidate beats from at least a first channel of the electrogram;

identifying a second-channel group of candidate beats from at least a second channel of an electrogram;

evaluating whether each first-channel beat candidate is near a second-channel beat candidate;

for each first-channel beat candidate near a second-channel beat candidate, comparing the amplitude of the first-channel beat candidate with an amplitude of a previous beat and an amplitude of a next beat on the first electrogram channel and removing first-channel beat candidates that have an amplitude that is outside of a first pre-determined range from either the amplitude of the previous beat or the amplitude of the next beat; and

for each first-channel beat candidate near a second-channel beat candidate, comparing the amplitude of the first-channel beat candidate with an amplitude of a previous beat candidate and an amplitude of a next beat candidate on the first electrogram channel and removing first-channel beat candidates that have an amplitude that is outside of a second pre-determined range from either the amplitude of the previous beat or the amplitude of the next beat candidate;

wherein a first-channel beat candidate is near a second-channel beat candidate if it occurs within a first time interval from the second-channel beat candidate.

2. The method of claim 1, wherein the first electrogram channel is an atrial channel electrogram and the second electrogram channel is a ventricular channel electrogram.

3. The method of claim 1, further comprising:

for each first-channel beat candidate of the first electrogram channel near a beat candidate from the second electrogram channel, comparing the amplitude of the first-channel beat candidate with an amplitude of a previous beat and an amplitude of a next beat on the first electrogram channel; and

removing first-channel beat candidates that have an amplitude that is outside of a third pre-determined range from either the amplitude of the previous beat or the amplitude of the next beat.

4. The method of claim 1, wherein the first-channel beat candidates further comprise locations of the first-channel beat candidates within the electrogram.

5. The method of claim 4, further comprising:

retrieving a group of device-identified beat locations within the electrogram;

comparing the group of device-identified beat locations to the locations of the remaining first-channel beat candidates; and

based on the comparing step, identifying oversensing of beats, undersensing of beats, or noise from the device.

6. The method of claim 1, wherein the first pre-determined range is between 10% and 250% of the amplitude of the previous beat or the next beat.

7. The method of claim 1, wherein the first pre-determined range is between 20% and 200% of the amplitude of the previous beat or the next beat.

8. The method of claim 1, wherein the second pre-determined range is betweenand 180% of the amplitude of the previous beat or the next beat.

9. The method of claim 1, wherein the first time interval is 100 milliseconds.

10. An off-line method for analyzing cardiac electrogram data, comprising:

retrieving an electrogram from a memory location;

identifying an initial first-channel group of candidate beats from at least a first channel of the electrogram;

identifying a second-channel group of candidate beats from at least a second channel of an electrogram;

evaluating whether each first-channel beat candidate is near a second-channel beat candidate;

for each initial first-channel beat candidate near a second-channel beat candidate, removing candidate beats from the group of initial first-channel candidate beats that meet a set of criteria, wherein the criteria comprises;

comprising comparing the amplitude of the initial first channel beat candidate with an amplitude of a previous beat and an amplitude of a next beat on the first electrogram channel and removing initial

(a) first-channel beat candidates that have an amplitude that is outside of a first pre-determined range from either the amplitude of a previous beat or the amplitude of a next beat, and the number of first-channel beat candidates that are outside of a first pre-determined range from either the previous or next beat exceeds a first pre-defined beat count threshold; and

wherein an initial first-channel beat candidate is near a second-channel beat candidate if it occurs within a first time interval from the second-channel beat candidate.

11. The method of claim 10, wherein the first electrogram channel is an atrial channel electrogram and the second electrogram channel is a ventricular channel electrogram.

12. The method of claim 10, wherein removing candidate beats from the group of initial first-channel candidate beats that do not meet a set of criteria further comprises comparing the amplitude of the initial first-channel beat candidate with an amplitude of a previous beat candidate and an amplitude of a next beat candidate on the first electrogram channel and removing initial first-channel beat candidates that have an amplitude that is outside of a second pre-determined range from either the amplitude of the previous beat or the amplitude of the next beat candidate.

13. The method of claim 12, wherein initial first-channel beat candidates that are outside of a second pre-determined range from either the previous or next beat candidate are removed only if the number of first-channel beat candidates that are outside of the second pre-determined range from either the previous or next beat exceeds a second pre-defined beat count threshold.

14. The method of claim 11, wherein the first pre-defined beat count threshold is 10% of the initial first-channel group of candidate beats.