Method and apparatus for identifying lead-related conditions using impedance trends and oversensing criteria

• US 20050137636A1
• Filed: 04/05/2004
• Published: 06/23/2005
• Est. Priority Date: 12/04/2003
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Wang, Li, Gunderson, Bruce D., Patel, Amisha S., Bounds, Chad A.
• Granted Patent: US 7,289,851 B2
• Time in Patent Office: Days
• US Class Current: 607/27
• CPC Class Codes: A61N 1/3706 Pacemaker parameters stimulation threshold A61N1/371

Abstract

A method and apparatus for detecting a lead-related condition that includes determining whether a first oversensing criteria is satisfied, determining whether a second oversensing criteria is satisfied, determining whether an impedance criteria has been satisfied, and generating an alert in response to more than one of the first oversensing criteria, the second over sensing criteria and the impedance criteria being satisfied.

Claims

1. An apparatus for determining a lead-related condition associated with an implantable medical device capable of being implanted in a patient, comprising:

a sensing device sensing intrinsic signals of the patient; and

a processing unit determining, in response to the sensed intrinsic signals, whether more than one of a first oversensing criteria, a second oversensing criteria and an impedance criteria have been satisfied.

2. The apparatus of claim 1, further comprising a notification system generating an alert in response to the processor unit determining more than one of the first oversensing criteria, the second oversensing criteria and the impedance criteria have been satisfied.

3. The apparatus of claim 1, wherein the processing unit determines the first oversening criteria is satisfied in response to determining that a predetermined number of RR-intervals that are within a first predetermined time period subsequent to a blanking period associated with a sensing device occur within a second predetermined time period.

4. The apparatus of claim 3, wherein the first predetermined time period is approximately equal to 20 ms, the second predetermined time period is approximately equal to 72 hours and the predetermined number of RR-intervals is approximately equal to 30 RR-intervals.

5. The apparatus of claim 3, wherein the processing unit determines the first oversensing criteria is satisfied in response to determining that the number of RR-intervals within the first predetermined time period is greater than a first predetermined threshold.

6. The apparatus of claim 5, wherein the first predetermined time period is approximately equal to 20 ms and the first predetermined threshold is approximately equal to 300 RR-intervals.

7. The apparatus of claim 5, wherein the processing unit determines the first oversensing criteria is satisfied in response to determining that a time duration window is not greater than a threshold time period and determining that a ratio of RR-intervals within the first predetermined time period occur.

8. The apparatus of claim 7, wherein the threshold time period is approximately equal to thirty days and the ratio of RR-intervals is greater than or equal to ten RR-intervals per day.

9. The apparatus of claim 7, wherein the processing unit determines the second oversensing criteria is satisfied in response to a predetermined number of events having average cycle lengths that are less than a second predetermined threshold occurring within a third predetermined time period.

10. The apparatus of claim 9, wherein the predetermined number of events is approximately equal to 2, the second predetermined threshold is approximately equal to 200 ms, and the third predetermined time period is approximately equal to one week.

11. The apparatus of claim 9, wherein the processing unit determines the impedance criteria has been satisfied in response to a set of diagnostic criteria being applied to a short-term lead-impedance trend and long-term impedance trend.

12. The apparatus of claim 11, further comprising:

a storage device storing information corresponding to the first oversensing criteria, the second oversensing criteria and the impedance criteria; and

a transmitting device transmitting the stored information to a remote device, wherein the determination whether the first oversensing criteria, the second oversensing criteria and the impedance criteria is performed by the processing unit at the remote device.

13. The apparatus of claim 2, wherein the alert is transmitted to a remote location.

14. The apparatus of claim 11, further comprising:

a storage device storing information corresponding to the first oversensing criteria, the second oversensing criteria and the impedance criteria in an implantable medical device;

a remote device remote from the implantable medical device;

a second processing unit; and

a transmitting device transmitting the stored information to the remote device in response to the processing unit determining one of the first oversensing criteria, the second oversensing criteria and the impedance criteria is satisfied, wherein the second processing unit determines whether the other of the first oversensing criteria, the second oversensing criteria and the impedance criteria are satisfied.

15. The apparatus of claim 1, wherein the processing unit determines the first oversensing criteria is satisfied in response to one of determining, during a first time period, whether a predetermined number of RR-intervals are within a second time period subsequent to a blanking period associated with a sensing device, determining, during a third time period subsequent to the first time period, a ratio of RR-intervals that are within the second predetermined time period subsequent, and determining, during a fourth time period subsequent to the second time period, whether the number of RR-intervals within the second predetermined time period is greater than a predetermined threshold.

16. The apparatus of claim 15, wherein the first time period is approximately equal to three days, the predetermined number of RR-intervals is approximately equal to thirty RR-intervals, the second time period is approximately equal to 20 ms, the third time period is approximately equal to thirty days, the ratio is greater than or equal to ten RR-intervals per day, and the predetermined threshold is approximately equal to three hundred RR-intervals.

17. A method for detecting a lead-related condition, comprising:

determining whether a first oversensing criteria is satisfied;

determining whether a second oversensing criteria is satisfied;

determining whether an impedance criteria has been satisfied; and

generating an alert in response to more than one of the first oversensing criteria, the second over sensing criteria and the impedance criteria being satisfied.

18. The method of claim 17, wherein determining whether a first oversensing criteria is satisfied comprises:

determining whether a predetermined number of RR-intervals are within a first predetermined time period subsequent to a blanking period associated with a sensing device; and

determining whether the predetermined number of RR-intervals occur within a second predetermined time period.

19. The method of claim 18, wherein the first predetermined time period is approximately equal to 20 ms.

20. The method of claim 18, wherein the second predetermined time period is approximately equal to 72 hours and the predetermined number of RR-intervals is approximately equal to 30 RR-intervals.

21. The method of claim 17, wherein determining whether a first oversensing criteria is satisfied comprises:

determining a number of RR-intervals that are within a first predetermined time period subsequent to a blanking period associated with a sensing device; and

determining whether the number of RR-intervals within the first predetermined time period is greater than a predetermined threshold.

22. The method of claim 21, wherein the first predetermined time period is approximately equal to 20 ms.

23. The method of claim 21, wherein the predetermined threshold is approximately equal to 300 RR-intervals.

24. The method of claim 17, wherein determining whether a first oversensing criteria is satisfied comprises:

determining whether a time duration window is greater than a threshold time period; and

determining, in response to the time duration window not being greater than the threshold time period, a ratio of RR-intervals that are within a first predetermined time period subsequent to a blanking period associated with a sensing device.

25. The method of claim 24, wherein the threshold time period is approximately equal to thirty days.

26. The method of claim 24, wherein the ratio is greater than or equal to ten RR-intervals per day.

27. The method of claim 17, wherein determining whether a second oversensing criteria is satisfied comprises determining whether there are a predetermined number of events having average cycle lengths that are less than a predetermined threshold occurring within a predetermined time period.

28. The method of claim 27, wherein the predetermined number of events is approximately equal to 2, the predetermined threshold is approximately equal to 200 ms, and the predetermined time period is approximately equal to one week.

29. The method of claim 17, wherein determining whether an impedance criteria has been satisfied comprises:

measuring a lead impedance;

determining a short-term impedance trend;

determining a long-term impedance trend; and

applying a set of diagnostic criteria to the short-term and long-term impedance trends.

30. The method of claim 17, further comprising:

storing information corresponding to the first oversensing criteria, the second oversensing criteria and the impedance criteria in an implantable medical device; and

transmitting the stored information to a remote device, wherein the determination whether the first oversensing criteria, the second oversensing criteria and the impedance criteria is performed at the remote device.

31. The method of claim 17, wherein the alert is transmitted to a remote location.

32. The method of claim 17, further comprising:

storing information corresponding to the first oversensing criteria, the second oversensing criteria and the impedance criteria in an implantable medical device;

transmitting the stored information to a remote device in response to one of the first oversensing criteria, the second oversensing criteria and the impedance criteria being satisfied; and

determining whether the other of the first oversensing criteria, the second oversensing criteria and the impedance criteria are satisfied at the remote device.

33. The method of claim 17, wherein determining whether a first oversensing criteria is satisfied comprises:

determining, during a first time period, whether a predetermined number of RR-intervals are within a second predetermined time period subsequent to a blanking period associated with a sensing device;

determining, during a third time period subsequent to the first time period, a ratio of RR-intervals that are within the second predetermined time period subsequent; and

determining, during a fourth time period subsequent to the second time period, whether the number of RR-intervals within the second predetermined time period is greater than a predetermined threshold.

34. The method of claim 33, wherein the first time period is approximately equal to three days, the predetermined number of RR-intervals is approximately equal to thirty RR-intervals, the second predetermined time period is approximately equal to 20 ms, the third time period is approximately equal to thirty days, the ratio is greater than or equal to ten RR-intervals per day, and the predetermined threshold is approximately equal to three hundred RR-intervals.

35. An apparatus for determining a lead-related condition associated with an implantable medical device capable of being implanted in a patient, comprising:

means for determining whether a first oversensing criteria is satisfied;

means for determining whether a second oversensing criteria is satisfied;

means for determining whether an impedance criteria has been satisfied; and

means for generating an alert in response to more than one of the first oversensing criteria, the second over sensing criteria and the impedance criteria being satisfied.

36. A method for detecting a lead-related condition comprising:

measuring a lead impedance,

determining a short-term impedance trend,

determining a long-term impedance trend,

applying a set of diagnostic criteria to the short-term and long-term impedance trends,

determining a plurality of oversensing criteria; and

diagnosing a lead-related condition in response to the set of diagnostic criteria and the plurality of oversensing criteria.

37. The method of claim 36, wherein the method of periodically measuring a lead impedance includes comparing if a single measurement falls out of range.

38. The method of claim 37, wherein the method of diagnosing a lead-related condition includes subsequently storing diagnosis and supporting data with optimal recommendation and generating patient notification.

39. The method of claim 36, wherein determining a plurality of oversensing criteria includes determining whether a sensing integrity count has been met and detecting non-sustained events having a cycle length less than a predetermined threshold.

40. The method of claim 39, wherein the sensing integrity count corresponds to RR intervals less than 140 ms and the predetermined threshold is approximately equal to 200 ms.

41. The method of claim 40, wherein a lead-related condition is detected in response to the plurality of oversensing criteria being met.

42. The method of claim 40, wherein a lead-related condition is detected in response to a sensing criteria of the plurality of oversensing criteria and the diagnostic criteria being met.

43. A computer-readable medium having computer-executable instructions for performing a method, comprising:

determining whether a first oversensing criteria is satisfied;

determining whether a second oversensing criteria is satisfied;

determining whether an impedance criteria has been satisfied; and

generating an alert in response to more than one of the first oversensing criteria, the second over sensing criteria and the impedance criteria being satisfied.