Method and apparatus for identifying cardiac and non-cardiac oversensing using intracardiac electrograms

• US 20040015197A1
• Filed: 04/18/2003
• Published: 01/22/2004
• Est. Priority Date: 04/29/2002
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Gunderson, Bruce D.
• Granted Patent: US 7,783,354 B2
• Time in Patent Office: Days
• US Class Current: 607/27
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• 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: A61B 5/363 Detecting tachycardia or bradycardia
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: A61N 1/3925 Monitoring; Protecting

Abstract

A method and apparatus for automatically identifying various types of cardiac and non-cardiac oversensing and automatically performing a corrective action to reduce the likelihood of oversensing is provided. EGM data, including time intervals between sensed and paced events and signal morphologies, are analyzed for patterns indicative of various types of oversensing, including oversensing of far-field R-waves, R-waves, T-waves, or noise associated with electromagnetic interference, non-cardiac myopotentials, a lead fracture, or a poor lead connection. Identification of oversensing and its suspected cause are reported so that corrective action may be taken. The corrective action may include, for example, adjusting sensing parameters such as blanking periods, decay constants, decay delays, threshold values, sensitivity values, electrode configurations and the like.

Claims

1. A method comprising:

operating an implanted medical device in accordance with sensing parameters for a plurality of cardiac cycles;

identifying oversensing by the implanted medical device; and

automatically adjusting at least one of the sensing parameters of the implanted medical device in response to identifying the oversensing.

2. The method of claim 1, further comprising assessing whether the implanted medical device will appropriately detect a cardiac episode with the adjusted sensing parameters.

3. The method of claim 2, further comprising resetting the sensing parameter to an original setting upon determining the implanted medical device will not appropriately detect the cardiac episode with the adjusted sensing parameters.

4. The method of claim 1, further comprising:

determining an origin of the oversensing; and

automatically adjusting at least one sensing parameter based on the origin of the oversensing.

5. The method of claim 4, wherein the origin of the oversensing includes one of cardiac origin and non-cardiac origin.

6. The method of claim 5, wherein the oversensing from a cardiac origin includes one of T-wave oversensing, R-wave double counting, far-field R-wave oversensing, and P-wave oversensing.

7. The method of claim 5, wherein the oversensing from a non-cardiac origin includes one of myopotential oversensing and electromagnetic interference (EMI).

8. The method of claim 1, wherein automatically adjusting the sensing parameter includes automatically adjusting a programmed sensitivity of a sensing electrode.

9. The method of claim 1, wherein automatically adjusting the sensing parameter includes automatically adjusting a programmed threshold of a sensing electrode.

10. The method of claim 1, wherein automatically adjusting the sensing parameter includes automatically adjusting a programmed decay constant of a sensing electrode.

11. The method of claim 1, wherein automatically adjusting the sensing parameter includes automatically adjusting a programmed decay delay of a sensing electrode.

12. The method of claim 1, wherein automatically adjusting the sensing parameter includes automatically adjusting a programmed blanking period of a sensing electrode.

13. The method of claim 1, wherein automatically adjusting the sensing parameter includes automatically adjusting an electrode configuration of a sensing electrode.

14. The method of claim 13, wherein automatically adjusting the electrode configuration includes adjusting the electrode configuration from a true bipolar sensing (tip-to-ring) configuration to an integrated bipolar sensing (tip-to-coil) configuration.

15. The method of claim 1, further comprising reporting the adjustments to the sensing parameters to a physician upon interrogation.

16. The method of claim 1, wherein identifying oversensing by an implanted medical device includes identifying oversensing using intracardiac electrograms.

17. A computer-readable medium comprising instructions to cause a processor to:

operate an implanted medical device in accordance with sensing parameters for a plurality of cardiac cycles;

identify oversensing by the implanted medical device; and

automatically adjust at least one sensing parameter of the implanted medical device in response to identifying the oversensing.

18. The computer-readable medium of claim 17, further comprising instructions to cause the processor to:

determine an origin of the oversensing; and

automatically adjust the sensing parameter based on the origin of the oversensing.

19. The computer-readable medium of claim 17, wherein instructions to cause the processor to automatically adjust at least one sensing parameter of the implanted medical device includes instructions to cause the processor to automatically adjust at least one of a programmed sensitivity of a sensing electrode, a programmed threshold of a sensing electrode, a programmed decay constant of a sensing electrode, a programmed decay delay of a sensing electrode, a programmed blanking period of a sensing electrode, and an electrode configuration of a sensing electrode.

20. The computer-readable medium of claim 17, further comprising instructions to cause the processor to:

assess whether the implanted medical device will appropriately detect a cardiac episode with the adjusted sensing parameters; and

reset the sensing parameter to an original setting upon determining the implanted medical device will not appropriately detect the cardiac episode with the adjusted sensing parameters.

21. An implantable medical device comprising:

at least one sensing electrode to sense cardiac data from a heart of a patient in accordance with programmed sensing parameters for a plurality of cardiac cycles; and

a processor to identify oversensing by the implantable medical device based on the sensed cardiac data and automatically adjust at least one of the sensing parameter of the implantable medical device in response to identifying the oversensing.

22. The device of claim 21, wherein the processor assesses whether the implantable medical device will appropriately detect a cardiac episode with the adjusted sensing parameter.

23. The device of claim 22, wherein the processor resets the sensing parameter to an original setting upon determining the implantable medical device will not appropriately detect the cardiac episode with the adjusted sensing parameter.

24. The device of claim 21, wherein the processor determines an origin of the oversensing and automatically adjusts the sensing parameter based on the origin of the oversensing.

25. The device of claim 21, wherein the processor automatically adjusts a programmed sensitivity of the sensing electrode in response to identifying oversensing.

26. The device of claim 21, wherein the processor automatically adjusts a programmed threshold of the sensing electrode in response to identifying oversensing.

27. The device of claim 21, wherein the processor automatically adjusts a programmed decay constant of the sensing electrode in response to identifying oversensing.

28. The device of claim 21, wherein the processor automatically adjusts a programmed decay delay of the sensing electrode in response to identifying oversensing.

29. The device of claim 21, wherein the processor automatically adjusts a programmed blanking period of the sensing electrode in response to identifying oversensing.

30. The device of claim 21, wherein the processor automatically adjusts an electrode configuration of the sensing electrode in response to identifying oversensing.

31. The device of claim 30, wherein the processor automatically adjusts the electrode configuration from a true bipolar sensing (tip-to-ring) configuration to an integrated bipolar sensing (tip-to-coil) configuration.

32. The device of claim 21, wherein the implantable medical device reports the adjustment to the sensing parameter to a physician upon interrogation.

33. The device of claim 21, wherein the processor identifies oversensing by an implantable medical device using intracardiac electrograms.

34. An implantable medical device comprising:

means for operating an implantable medical device in accordance with sensing parameters for a plurality of cardiac cycles;

means for identifying oversensing by the implantable medical device; and

means for automatically performing a corrective action to reduce the likelihood of oversensing.

35. The device of claim 34, wherein means for automatically performing the corrective action includes means for adjusting at least one of the sensing parameters.

36. The device of claim 35, further comprising a sensing electrode to sense cardiac data, wherein the adjusted sensing parameter may include one of a programmed sensitivity of the sensing electrode, a programmed threshold of the sensing electrode, a programmed decay constant of the sensing electrode, a programmed decay delay of the sensing electrode, a programmed blanking period of the sensing electrode, and an electrode configuration of the sensing electrode.

37. The device of claim 34, further comprising means for assessing whether the implanted medical device will appropriately detect a cardiac episode with the adjusted sensing parameter.

38. The device of claim 34, further comprising means for determining an origin of the oversensing, and wherein the means for performing automatically perform the corrective action based on the origin of the oversensing.