Pacing output determination based on selected capture threshold values

• US 20070021793A1
• Filed: 07/19/2005
• Published: 01/25/2007
• Est. Priority Date: 07/19/2005
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Dong, Yanting, Meyer, Scott, Bohn, Derek, Yost, David, Voegele, John, Foster, Clayton, Stalsberg, Kevin, Enrooth, Eric
• Granted Patent: US 7,471,983 B2
• Time in Patent Office: Days
• US Class Current: 607/28
• CPC Class Codes: A61N 1/3712 Auto-capture, i.e. automatic adjustment of the stimulation threshold

Abstract

Approaches for adjusting the pacing energy delivered by a pacemaker are provided. Adjusting the pacing energy involves performing a plurality of capture threshold tests, each capture threshold test measuring a capture threshold of the heart. One or more measured captured thresholds are selected, including at least one capture threshold that is higher relative to other measured capture thresholds acquired by the plurality of capture threshold tests. The pacing energy is adjusted based on the one or more selected capture thresholds.

Claims

1. A method of adjusting a pacing energy delivered to a heart, comprising:

performing a plurality of capture threshold tests, each capture threshold test measuring a capture threshold of the heart;

selecting one or more measured captured thresholds, wherein one of the selected one or more capture thresholds is higher relative to other measured capture thresholds of the plurality of capture threshold tests; and

adjusting the pacing energy based on the one or more selected capture thresholds.

2. The method of claim 1, wherein performing the plurality of capture threshold tests comprises performing the plurality of capture threshold tests at predetermined intervals selected to cover the patient'"'"'s circadian cycle.

3. The method of claim 1, wherein selecting the one or more measured capture thresholds comprises selecting a highest capture threshold acquired by the plurality of capture tests.

4. The method of claim 1, wherein adjusting the pacing energy comprises adjusting the pacing energy to a highest capture threshold measured by the plurality of capture threshold tests plus a safety margin.

5. The method of claim 1, wherein adjusting the pacing energy comprises adjusting the pacing energy to a predetermined value if a predetermined number of capture threshold tests are unsuccessful.

6. The method of claim 1, wherein adjusting the pacing energy comprises responding to an increasing capture threshold trend more quickly than to a decreasing capture threshold trend.

7. The method of claim 1, wherein performing the plurality of capture threshold tests comprises performing a plurality of system-initiated capture threshold tests.

8. The method of claim 7, further comprising:

storing capture thresholds acquired by the plurality of system-initiated capture threshold tests;

performing a commanded capture threshold test; and

clearing the stored capture thresholds and storing a commanded capture threshold test result if the commanded capture threshold test is successful.

9. The method of claim 8, further comprising adjusting the pacing energy based on the commanded capture threshold test result.

10. The method of claim 1, wherein performing the plurality of capture threshold tests comprises storing results of the plurality of capture threshold tests in a moving window buffer.

11. The method of claim 1, wherein selecting the one or more measured capture thresholds comprises:

selecting a stored capture threshold value, the stored capture threshold value acquired during a predetermined time interval occurring prior to switching to a pacing energy adjustment mode; and

setting the pacing energy to a default value if there is no stored capture threshold value acquired during the predetermined time interval.

12. A pacing energy adjustment system, comprising:

capture threshold testing circuitry configured to perform a plurality of capture threshold tests, each capture threshold test measuring a capture threshold of the heart; and

a processor, coupled to the capture threshold testing circuitry, the processor configured to select at least one measured captured threshold that is higher relative to other measured capture thresholds acquired by the plurality of capture threshold tests and to adjust a pacing energy based on the at least one selected capture threshold.

13. The system of claim 12, wherein the plurality of capture threshold tests are performed at time intervals selected to cover a patient'"'"'s circadian cycle.

14. The system of claim 12, wherein the processor is configured to operate in several modes including a capture threshold trend mode and a pacing energy adjust mode.

15. The system of claim 12, wherein the processor is configured to set the pacing energy to a default value if a predetermined number of capture threshold tests of the plurality of capture threshold tests are unsuccessful.

16. The system of claim 12, further comprising a moving window buffer configured to store a predetermined number of capture thresholds measured by the plurality of capture threshold tests.

17. The system of claim 16, wherein the processor is configured to adjust the pacing energy based on a capture threshold stored in a moving window buffer.

18. The system of claim 12, wherein the processor is configured to adjust the pacing energy based on a capture threshold acquired by a commanded capture threshold test.

19. The system of claim 12, wherein the processor is a component of an implantable cardiac rhythm management system.

20. The system of claim 12, wherein the plurality of capture threshold tests are initiated by an implantable device.

21. The system of claim 12, wherein the plurality of capture threshold tests are initiated by a remote device.

22. A system for setting pacing output energy, comprising:

capture threshold circuitry configured to perform a plurality of capture threshold tests, each capture threshold test measuring a capture threshold of the heart;

means for selecting one or more measured captured thresholds, wherein one of the selected one or more capture thresholds is higher relative to other measured capture thresholds of the plurality of capture threshold tests; and

means for adjusting the pacing energy based on the one or more selected capture thresholds.

23. The system of claim 22, wherein the plurality of capture threshold tests are performed at predetermined intervals selected to cover the patient'"'"'s circadian cycle.

24. The system of claim 22, further comprising:

means for selecting a highest capture threshold acquired by the plurality of capture tests; and

means for adjusting the pacing energy based on the highest capture threshold.