Method and apparatus for reducing inappropriate detection of lead-related noise

• US 9,636,506 B2
• Filed: 01/03/2008
• Issued: 05/02/2017
• Est. Priority Date: 04/18/2003
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Gunderson, Bruce D.
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): Bays, Pamela M
• Application Number:
  US11/969,068
• Publication Number:
  US 20080172098A1
• Time in Patent Office: 3,407 Days
• Field of Search: 600509, 600510, 600547, 607 5, 607 7, 607 8, 607 9, 607 11, 607 27, 607 28
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: A61N 1/3704 Circuits specially adapted therefor, e.g. for sensitivity control
• CPC Class Codes: A61N 1/37258 Alerting the patient
• CPC Class Codes: A61N 1/37282 characterised by communication with experts in remote locations using a network
• CPC Class Codes: A61N 1/3925 Monitoring; Protecting

Abstract

An implantable medical device detects conditions such as a lead failure which may result in oversensing a physiologic condition. In response, the IMD automatically adjusts sensing thresholds, such as the number of intervals to detection in order to mitigate the effect of oversensing in the delivery of extraneous therapy.

Claims

1. An implantable medical device (IMD) comprising:

at least one lead that includes 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 housing coupled to the leads and containing a processor configured to analyze the sensed cardiac data to determine if an oversensing criteria is satisfied, identify whether a lead failure exists based on the oversensing criteria being satisfied and at least one other criteria, and automatically adjust a programmed number of intervals to detection (NID) from the programmed number to an increased value in response to identifying that the lead failure exists, and maintain the NID at the programmed number in response to determining that the oversensing criteria is satisfied and not identifying that the lead failure exists.

2. The IMD of claim 1, further comprising a transmitter operatively coupled with the processor to transmit an alert to at least one of a patient or a physician indicating the lead failure has been identified.

3. The IMD of claim 1, wherein the NID is increased from the programmed number to requiring detection in 18 out of 24 events.

4. The IMD of claim 1, wherein the NID is increased from the programmed number to requiring detection in 24 out of 32 events.

5. The IMD of claim 1, wherein the NID is increased from the programmed number to requiring detection in 30 out of 40 events.

6. The IMD of claim 1, wherein the processor determines that the first oversensing criteria is satisfied when a predetermined number of RR-intervals are less than a first predetermined threshold within a first predetermined time period.

7. The IMD of claim 1, wherein the processor determines that the second oversensing criteria is satisfied when a predetermined number of non-sustained ventricular tachycardia events having average cycle lengths that are less than a second predetermined threshold occur within a second predetermined time period.

8. The IMD of claim 1, wherein the processor determines that the impedance criteria is satisfied based on at least one impedance measurement.

9. The IMD of claim 1, wherein the processor is configured to identify whether the lead-related condition exists based on the oversensing criteria being satisfied and at least one a second oversensing criteria and an impedance criteria being satisfied.

10. The IMD of claim 1, further comprising a timer initiated for a predetermined duration in response to the processor adjusting the programmed NID to the increased value, wherein upon expiration of the timer the processor adjusts the NID again.

11. The IMD of claim 10, wherein the predetermined duration is 96 hours.

12. The IMD of claim 10, wherein upon expiration of the timer the processor adjusts the NID again to the programmed number.

13. The IMD of claim 10, wherein upon expiration of the timer the processor adjusts the NID again to a value less than the increased value and more than the programmed number.

14. An implantable medical device (IMD) comprising:

at least one lead;

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

a processor operatively coupled with the lead and configured to identify a lead failure and automatically adjust a programmed number of intervals to detection (NID) from the programmed number to an increased value solely in response to identifying the lead failure; and

a timer initiated for a predetermined duration in response to the automatic adjustment of the NID, wherein upon expiration of the timer the processor adjusts the NID again.

15. The IMD of claim 14, further comprising a transmitter operatively coupled with the processor and configured to transmit at least one of a patient alert and a physician alert upon one of adjusting the NID and identifying the lead failure.

16. The IMD of claim 14, wherein the NID is adjusted from the programmed number to 18 out of 24 intervals.

17. The IMD of claim 14, wherein the NID is adjusted from the programmed number to 24 out of 32 intervals.

18. The IMD of claim 14, wherein the NID is adjusted from the programmed number to 30 out of 40 intervals.

19. The IMD of claim 14, wherein the processor is configured to identify a lead failure based on at least one impedance measurement.

20. A method comprising:

sensing cardiac data from a heart of a patient with at least one electrode coupled to at least one lead of an implantable medical device (IMD) in accordance with programmed sensing parameters for a plurality of cardiac cycles;

analyzing the sensed cardiac data to determine if an oversensing criteria is satisfied;

identifying whether a lead-related condition exists based on the oversensing criteria being satisfied and at least one other criteria;

automatically adjusting a programmed number of intervals to detection (NID) from the programmed number to an increased value in response to identifying that the lead-related condition exists; and

maintaining the NID at the programmed number in response to determining that the oversensing criteria is satisfied and not identifying that the lead-related condition exists.

21. The method of claim 20, wherein identifying whether the lead-related condition exists based on the oversensing criteria being satisfied and at least one other criteria comprises identifying whether the lead-related condition exists based on the oversensing criteria being satisfied and at least one a second oversensing criteria and an impedance criteria being satisfied.

22. An implantable medical device (IMD) comprising:

at least one lead that includes 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;

a housing coupled to the leads and containing a processor configured to obtain impedance data, analyze the impedance data to determine if an impedance criteria has been satisfied, analyze the sensed cardiac data to determine if a first oversensing criteria and a second oversensing criteria are satisfied, and automatically adjust a programmed number of intervals to detection (NID) based on the analysis of the impedance data and the sensed cardiac data,

wherein the processor is further configured to increase the NID from the programmed number to an increased value in response to determining the impedance criteria is satisfied and at least one of the first or second oversensing criteria are satisfied and maintains the NID at the programmed number in response to determining that one of the first or second oversensing criteria is satisfied, but the impedance criteria and the remaining one of the first and second oversensing criteria are not satisfied.

23. The IMD of claim 22, wherein the processor is configured to determine that the first oversensing criteria is satisfied when the analysis of the sensed cardiac data indicates a predetermined number of RR-intervals are less than a first predetermined threshold within a first predetermined time period;

the processor is configured to determine that the second oversensing criteria is satisfied when the analysis of the sensed cardiac data indicates a predetermined number of non-sustained ventricular tachycardia events having average cycle lengths that are less than a second predetermined threshold occurr within a second predetermined time period.

24. The IMD of claim 22, wherein the processor is configured to adjust the programmed NID to the increased value in response to determining that both the first oversensing criteria and the second oversensing criteria are satisfied, but the impedance criteria is not satisfied.