Confirming sensed atrial events for pacing during resynchronization therapy in a cardiac medical device and medical device system

• US 10,004,906 B2
• Filed: 07/16/2015
• Issued: 06/26/2018
• Est. Priority Date: 07/16/2015
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Ghosh, Subham, Du, Juan, Greenhut, Saul E, Hemming, Michael T
• Primary Examiner(s): Wu, Eugene T
• Application Number:
  US14/801,049
• Publication Number:
  US 20170014629A1
• Time in Patent Office: 1,076 Days
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• 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 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy
• CPC Class Codes: A61N 1/36507 controlled by gradient or slope of the heart potential
• CPC Class Codes: A61N 1/3682 with a variable atrioventricular delay
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators

Abstract

A medical device and medical device system for controlling delivery of therapeutic stimulation pulses that includes a sensing device to sense a cardiac signal and emit a trigger signal in response to the sensed cardiac signal, a therapy delivery device to receive the trigger signal and deliver therapy to the patient in response to the emitted trigger signal, and a processor positioned within the sensing device, the processor configured to determine whether the sensed cardiac signal exceeds a possible P-wave threshold, compare a portion of the sensed cardiac signal to a P-wave template having a sensing window having a length less than a width of the P-wave, confirm an occurrence of a P-wave signal in response to the comparing, emit the trigger signal in response to the occurrence of a P-wave signal being confirmed, and inhibit delivery of the emitting signal in response to the occurrence of a P-wave signal not being confirmed.

Claims

1. A medical device system for controlling delivery of therapeutic stimulation pulses, the medical device system comprising:

a sensing device configured to;

sense a cardiac signal of a patient; and

emit a trigger signal in response to the sensed cardiac signal;

a therapy delivery device configured to;

receive the trigger signal; and

deliver therapy to the patient in response to the emitted trigger signal; and

a processor positioned within the sensing device, the processor being configured to;

determine whether the sensed cardiac signal exceeds a P-wave candidate threshold;

compare, in response to a determination that the sensed cardiac signal exceeds the P-wave candidate threshold, a portion of the sensed cardiac signal to a P-wave template, the P-wave template comprising a sensing window having a length less than a width of a P-wave with a predetermined P-wave morphology, the sensing window corresponding to a time window that ends prior to an end of the P-wave with the predetermined P-wave morphology;

confirm an occurrence of a P-wave in the sensed cardiac signal in response to the comparison between the portion of the sensed cardiac signal and the P-wave template;

generate, in response to the occurrence of the P-wave in the sensed cardiac signal being confirmed, the trigger signal emitted by the sensing device; and

inhibit delivery of the trigger signal in response to the occurrence of the P-wave in the sensed cardiac signal not being confirmed.

2. The medical device system of claim 1, wherein the sensing device comprises a subcutaneous device capable of being implanted subcutaneously within a patient and the therapy delivery device comprises a transcatheter intracardiac pacemaker adapted for implantation wholly within a heart chamber.

3. The medical device system of claim 1, wherein the sensing device comprises subcutaneously implanted electrodes to sense the cardiac signal.

4. The medical device system of claim 1, wherein the sensing device comprises a subcutaneously implanted leadless device.

5. The medical device system of claim 1, wherein the length of the sensing window of the P-wave template corresponds to a predetermined percentage of the width of the P-wave with the predetermined P-wave morphology.

6. The medical device system of claim 5, wherein the predetermined percentage is fifty percent (50%).

7. The medical device system of claim 1, wherein the therapeutic stimulation pulses comprise cardiac resynchronization therapy pacing pulses.

8. The medical device system of claim 1, wherein the P-wave candidate threshold comprises at least one of an amplitude or a slope.

9. A medical device system for controlling delivery of therapeutic stimulation pulses, the medical device system comprising:

a sensing device configured to;

sense a cardiac signal of a patient; and

emit a trigger signal in response to the sensed cardiac signal;

a therapy delivery device configured to;

receive the trigger signal; and

deliver therapy to the patient in response to the emitted trigger signal; and

a processor positioned within the sensing device, the processor being configured to;

determine whether the cardiac signal comprises a T-wave;

determine, in response to a determination that the cardiac signal comprises a T-wave, whether the sensed cardiac signal exceeds a P-wave candidate threshold;

compare, in response to a determination that the sensed cardiac signal exceeds the P-wave candidate threshold, a portion of the sensed cardiac signal to a P-wave template, the P-wave template comprising a sensing window having a length less than a width of a P-wave with a predetermined P-wave morphology, the sensing window corresponding to a time window that ends prior to an end of the P-wave with the predetermined P-wave morphology;

confirm an occurrence of a P-wave in the sensed cardiac signal in response to the comparison between the portion of the sensed cardiac signal and the P-wave template;

generate, in response to the occurrence of a P-wave in the sensed cardiac signal being confirmed, the trigger signal emitted by the sensing device; and

inhibit delivery of the trigger signal in response to one of the T-wave not occurring and the occurrence of the P-wave in the sensed cardiac signal not being confirmed.

10. The medical device system of claim 9, wherein the sensing device comprises a subcutaneous device capable of being implanted subcutaneously within a patient and the therapy delivery device comprises a transcatheter intracardiac pacemaker adapted for implantation wholly within a heart chamber.

11. The medical device system of claim 9, wherein the sensing device comprises subcutaneously implanted electrodes to sense the cardiac signal.

12. The medical device system of claim 9, wherein the sensing device comprises a subcutaneously implanted leadless device.

13. The medical device system of claim 9, wherein the length of the sensing window of the P-wave template corresponds to a predetermined percentage of the width of the P-wave with the predetermined P-wave morphology.

14. The medical device system of claim 13, wherein the predetermined percentage is fifty percent (50%).

15. The medical device system of claim 9, wherein the therapeutic stimulation pulses comprise cardiac resynchronization therapy pacing pulses.

16. The medical device system of claim 9, wherein the P-wave candidate threshold comprises at least one of an amplitude or a slope.

17. A method of delivering therapeutic stimulation pulses, the method comprising:

sensing a cardiac signal of a patient;

receiving a trigger signal;

delivering therapy to the patient via a therapy delivery device in response to the emitted trigger signal;

determining whether the sensed cardiac signal exceeds a P-wave candidate threshold;

comparing, in response to determining that the sensed cardiac signal exceeds the P-wave candidate threshold, a portion of the sensed cardiac signal to a P-wave template, the P-wave template comprising a sensing window having a length less than a width of a P-wave with a predetermined P-wave morphology, the sensing window corresponding to a time window that ends prior to an end of the P-wave with the predetermined P-wave morphology;

confirming an occurrence of a P-wave in the sensed cardiac signal in response to the comparison between the portion of the sensed cardiac signal and the P-wave template;

generating the trigger signal in response to the occurrence of the P-wave in the sensed cardiac signal being confirmed; and

inhibiting delivery of the trigger signal in response to the occurrence of the P-wave in the sensed cardiac signal not being confirmed.

18. The method of claim 17, wherein the sensing device comprises a subcutaneous device capable of being implanted subcutaneously within a patient and the therapy delivery device comprises a transcatheter intracardiac pacemaker adapted for implantation wholly within a heart chamber.

19. The method of claim 17, wherein the sensing device comprises subcutaneously implanted electrodes to sense the cardiac signal.

20. The method of claim 17, wherein the sensing device comprises a subcutaneously implanted leadless device.

21. The method of claim 17, wherein the length of the sensing window of the P-wave template corresponds to a predetermined percentage of the width of the P-wave with the predetermined P-wave morphology.

22. The method of claim 21, wherein the predetermined percentage is fifty percent (50%).

23. The method of claim 17, wherein the therapeutic stimulation pulses comprise cardiac resynchronization therapy pacing pulses.

24. The method of claim 17, wherein the P-wave candidate threshold comprises at least one of an amplitude or a slope.

25. A method of delivering therapeutic stimulation pulses, the method comprising:

sensing a cardiac signal of a patient;

receiving a trigger signal;

delivering therapy to the patient via a therapy delivery device in response to the emitted trigger signal;

determining whether the cardiac signal comprises a T-wave;

determining, in response to a T-wave occurring, whether the sensed cardiac signal exceeds a P-wave candidate threshold;

comparing, in response to determining that the sensed cardiac signal exceeds the P-wave candidate threshold, a portion of the sensed cardiac signal to a P-wave template, the P-wave template comprising a sensing window having a length less than a width of a P-wave with a predetermined P-wave morphology, the sensing window corresponding to a time window that ends prior to an end of the P-wave with the predetermined P-wave morphology;

confirming an occurrence of a P-wave in the sensed cardiac signal in response to the comparison between the portion of the sensed cardiac signal and the P-wave template;

generating the trigger signal in response to the occurrence of the P-wave in the sensed cardiac signal being confirmed; and

inhibiting delivery of the trigger signal in response to one of the T-wave not occurring and the occurrence of the P-wave in the sensed cardiac signal not being confirmed.

26. The method of claim 25, wherein the sensing device comprises a subcutaneous device capable of being implanted subcutaneously within a patient and the therapy delivery device comprises a transcatheter intracardiac pacemaker adapted for implantation wholly within a heart chamber.

27. The method of claim 25, wherein the sensing device comprises subcutaneously implanted electrodes to sense the cardiac signal.

28. The method of claim 25, wherein the sensing device comprises a subcutaneously implanted leadless device.

29. The method of claim 25, wherein the length of the sensing window of the P-wave template corresponds to a predetermined percentage of the width of the P-wave with the predetermined P-wave morphology.

30. The method of claim 29, wherein the predetermined percentage is fifty percent (50%).

31. The method of claim 25, wherein the therapeutic stimulation pulses comprise cardiac resynchronization therapy pacing pulses.

32. The method of claim 25, wherein the possible P-wave threshold comprises at least one of an amplitude or a slope.

33. A medical device for controlling delivery of therapeutic stimulation pulses, the medical device comprising:

a subcutaneous sensing device comprising subcutaneously implanted electrodes configured to sense a cardiac signal of a patient;

an emitting device configured to emit a trigger signal to deliver the therapeutic stimulation pulses in response to the sensed cardiac signal; and

a processor positioned within the subcutaneous sensing device, the processor configured to;

determine whether the sensed cardiac signal exceeds a P-wave candidate threshold,

compare, in response to a determination that the sensed cardiac signal exceeds the P-wave candidate threshold, a portion of the sensed cardiac signal to a P-wave template, the P-wave template comprising a sensing window having a length less than a width of a P-wave with a predetermined P-wave morphology, the sensing window corresponding to a time window that ends prior to an end of the P-wave with the predetermined P-wave morphology;

confirm an occurrence of a P-wave in the sensed cardiac signal in response to the comparison between the portion of the sensed cardiac signal and the P-wave template;

generate, in response to the occurrence of the P-wave in the sensed cardiac signal being confirmed, the trigger signal emitted by the emitting device; and

inhibit delivery of the trigger signal in response to the occurrence of the P-wave in the sensed cardiac signal not being confirmed.

34. The medical device of claim 33, wherein the length of the sensing window of the P-wave template corresponds to a predetermined percentage of the width of the P-wave with the predetermined P-wave morphology.

35. The medical device of claim 34, wherein the predetermined percentage is fifty percent (50%).

36. The medical device of claim 33, wherein the therapeutic stimulation pulses comprise cardiac resynchronization therapy pacing pulses.

37. The medical device of claim 33, wherein the P-wave candidate threshold comprises at least one of an amplitude or a slope.