METHOD AND APPARATUS FOR BEAT ACQUISITION DURING TEMPLATE GENERATION IN A MEDICAL DEVICE HAVING DUAL SENSING VECTORS

• US 20160213941A1
• Filed: 01/23/2015
• Published: 07/28/2016
• Est. Priority Date: 01/23/2015
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Zhang, Xusheng
• Granted Patent: US 10,188,867 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/35 by template matching
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/6869 Heart
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/3624 occurring in the atrium, i.e. atrial tachycardia
• CPC Class Codes: A61N 1/36507 controlled by gradient or slope of the heart potential
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: A61N 1/3956 Implantable devices for applying electric shocks to the heart, e.g. for cardioversion
• CPC Class Codes: A61N 1/3987 characterised by the timing or triggering of the shock
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

A method and medical device for generating a template that includes sensing a cardiac signal from a plurality of electrodes, determining a plurality of beats in response to the sensed cardiac signal, determining whether to store a beat of the plurality of beats in a subgroup of a plurality of subgroups for storing beats, determining whether a number of beats stored in one of the plurality of subgroups exceeds a subgroup threshold, and generating a template in response to beats stored in the one of the plurality of subgroups that exceeds the subgroup threshold.

Claims

1. A method of generating a template in a medical device, comprising:

sensing a cardiac signal from a plurality of electrodes;

determining a plurality of beats in response to the sensed cardiac signal;

determining whether to store a beat of the plurality of beats in a subgroup of a plurality of subgroups for storing beats;

determining whether a number of beats stored in one of the plurality of subgroups exceeds a subgroup threshold; and

generating a template in response to beats stored in the one of the plurality of subgroups that exceeds the subgroup threshold.

2. The method of claim 1, further comprising:

determining, in response to storing a first beat of the plurality of beats in a first subgroup of the plurality of subgroups, whether the first beat is the initial beat to be stored in the first subgroup; and

setting the first beat as a first subgroup template beat in response to the beat being the initial beat.

3. The method of claim 1, further comprising:

storing a first beat of the plurality of beats within a first subgroup of the plurality of subgroups;

setting the first beat as a first subgroup template beat;

comparing a second beat of the plurality of beats to the first subgroup template beat and determining a match between the second beat and the first subgroup template beat;

determining whether the match is greater than a match threshold; and

storing the second beat within the first subgroup in response to the match being greater than the match threshold.

4. The method of claim 3, further comprising:

determining, in response to the match not being greater than the match threshold, whether a second subgroup has been created; and

setting the second beat as a second subgroup template beat in response to a second beat subgroup not being created.

5. The method of claim 4, further comprising:

comparing the second beat to a second subgroup template beat of the second subgroup in response to a second subgroup being created;

determining a match between the second beat and the second subgroup template beat;

determining whether the match between the second beat and the second subgroup template beat is greater than the match threshold; and

storing the second beat within the second subgroup in response to the match between the second beat and the second subgroup template beat being greater than the match threshold.

6. The method of claim 3, further comprising:

comparing the second beat to a second subgroup template beat of a second subgroup and determining a match between the second beat and the second subgroup template beat in response to the match between the second beat and the first subgroup template beat not being greater than the match threshold;

determining whether the match between the second beat and the second subgroup template beat is greater than the match threshold; and

storing the second beat within the second subgroup in response to the match between the second beat and the second subgroup template beat being greater than the match threshold.

7. The method of claim 1, wherein the plurality of beats comprises 15 beats and the subgroup threshold comprises 10 beats.

9. The method of claim 1, further comprising:

determining, in response to one of the number of beats stored in one of the plurality of subgroups not exceeding the subgroup threshold or a beat of the plurality of beats not being stored in one of the plurality of subgroups, a next plurality of beats in response to the sensed cardiac signal;

determining whether to store a beat of the next plurality of beats in a subgroup of a plurality of subgroups for storing beats;

determining whether a number of beats of the next plurality of beats stored in one of the plurality of subgroups exceeds a subgroup threshold; and

generating a template in response to the number of beats stored in the one of the plurality of subgroups exceeding the subgroup threshold.

8. The method of claim 8, wherein the plurality of subgroups comprises 4 subgroups.

10. (canceled)

11. A medical device for generating a template, comprising:

a plurality of electrodes sensing a cardiac signal;

a storage device comprising a plurality of subgroups for storing beats; and

a processor configured to determine a plurality of beats in response to the sensed cardiac signal, determine whether to store, within the storage device, a beat of the plurality of beats in a subgroup of the plurality of subgroups for storing beats, determine whether a number of beats stored in one of the plurality of subgroups exceeds a subgroup threshold, and generate a template in response to beats stored in the one of the plurality of subgroups that exceeds the subgroup threshold.

12. The medical device of claim 11, wherein the processor is configured to determine, in response to storing a first beat of the plurality of beats in a first subgroup of the plurality of subgroups, whether the first beat is the initial beat to be stored in the first subgroup, and set the first beat as a first subgroup template beat in response to the beat being the initial beat.

13. The medical device of claim 11, wherein the processor is configured to store a first beat of the plurality of beats within a first subgroup of the plurality of subgroups, set the first beat as a first subgroup template beat, compare a second beat of the plurality of beats to the first subgroup template beat and determine a match between the second beat and the first subgroup template beat, determine whether the match is greater than a match threshold, and store the second beat within the first subgroup in response to the match being greater than the match threshold.

14. The medical device of claim 13, wherein the processor is configured to determine, in response to the match not being greater than the match threshold, whether a second subgroup has been created, and set the second beat as a second subgroup template beat in response to a second beat subgroup not being created.

15. The medical device of claim 14, wherein the processor is configured to compare the second beat to a second subgroup template beat of the second subgroup in response to a second subgroup being created, determine a match between the second beat and the second subgroup template beat, determine whether the match between the second beat and the second subgroup template beat is greater than the match threshold, and store the second beat within the second subgroup in response to the match between the second beat and the second subgroup template beat being greater than the match threshold.

16. The medical device of claim 13, wherein the processor is configured to compare the second beat to a second subgroup template beat of a second subgroup and determine a match between the second beat and the second subgroup template beat in response to the match between the second beat and the first subgroup template beat not being greater than the match threshold, determine whether the match between the second beat and the second subgroup template beat is greater than the match threshold, and store the second beat within the second subgroup in response to the match between the second beat and the second subgroup template beat being greater than the match threshold.

17. The medical device of claim 11, wherein the plurality of beats comprises 15 beats and the subgroup threshold comprises 10 beats.

19. The medical device of claim 11, wherein the processor is configured to determine, in response to one of the number of beats stored in one of the plurality of subgroups not exceeding the subgroup threshold or a beat of the plurality of beats not being stored in one of the plurality of subgroups, a next plurality of beats in response to the sensed cardiac signal, determine whether to store a beat of the next plurality of beats in a subgroup of a plurality of subgroups for storing beats, determine whether a number of beats of the next plurality of beats stored in one of the plurality of subgroups exceeds a subgroup threshold, and generate a template in response to next beats stored in the one of the plurality of subgroups that exceeds the subgroup threshold.

20. The medical device of claim 11, wherein the plurality of electrodes form a first sensing vector sensing a first interval of the cardiac signal during a predetermined time period and a second sensing vector simultaneously sensing a second interval of the cardiac signal during the predetermined time period, and wherein the processor is configured to determine determining interval conditions in response to the first interval and the second interval, and determine whether to identify the first interval and the second interval as qualified intervals for generating a template in response to the determined intervals conditions.

18. The medical device of claim 18, wherein the plurality of subgroups comprises 4 subgroups.

23. (canceled)

24. A non-transitory, computer-readable storage medium storing instructions for causing a processor included in a medical device to perform a method for generating a template, the method comprising:

sensing a cardiac signal from a plurality of electrodes;

determining a plurality of beats in response to the sensed cardiac signal;

determining whether to store a beat of the plurality of beats in a subgroup of a plurality of subgroups for storing beats;

determining whether a number of beats stored in one of the plurality of subgroups exceeds a subgroup threshold; and

generating a template in response to beats stored in the one of the plurality of subgroups that exceeds the subgroup threshold.

25. A subcutaneous cardiac device for generating a template, comprising:

a plurality of electrodes sensing a cardiac signal;

a storage device;

a processor configured to determining a plurality of beats in response to the sensed cardiac signal, determine whether to store a beat of the plurality of beats in a subgroup of a plurality of subgroups of the storage device for storing beats, determine whether a number of beats stored in one of the plurality of subgroups exceeds a subgroup threshold, generate a template in response to beats stored in the one of the plurality of subgroups that exceeds the subgroup threshold, and detect a cardiac event in response to the generated template; and

a high voltage output circuit to deliver therapy via electrodes of the plurality of electrodes in response to the processor detecting the cardiac event in response to the generated template.

26. The subcutaneous cardiac device of claim 25, wherein the processor is configured to determine, in response to storing a first beat of the plurality of beats in a first subgroup of the plurality of subgroups, whether the first beat is the initial beat to be stored in the first subgroup, and set the first beat as a first subgroup template beat in response to the beat being the initial beat.

27. The subcutaneous cardiac device of claim 25, wherein the processor is configured to store a first beat of the plurality of beats within a first subgroup of the plurality of subgroups, set the first beat as a first subgroup template beat, compare a second beat of the plurality of beats to the first subgroup template beat and determine a match between the second beat and the first subgroup template beat, determine whether the match is greater than a match threshold, and store the second beat within the first subgroup in response to the match being greater than the match threshold.

28. The subcutaneous cardiac device of claim 27, wherein the processor is configured to determine, in response to the match not being greater than the match threshold, whether a second subgroup has been created, and set the second beat as a second subgroup template beat in response to a second beat subgroup not being created.

29. The subcutaneous cardiac device of claim 28, wherein the processor is configured to compare the second beat to a second subgroup template beat of the second subgroup in response to a second subgroup being created, determine a match between the second beat and the second subgroup template beat, determine whether the match between the second beat and the second subgroup template beat is greater than the match threshold, and store the second beat within the second subgroup in response to the match between the second beat and the second subgroup template beat being greater than the match threshold.

30. The subcutaneous cardiac device of claim 27, wherein the processor is configured to compare the second beat to a second subgroup template beat of a second subgroup and determine a match between the second beat and the second subgroup template beat in response to the match between the second beat and the first subgroup template beat not being greater than the match threshold, determine whether the match between the second beat and the second subgroup template beat is greater than the match threshold, and store the second beat within the second subgroup in response to the match between the second beat and the second subgroup template beat being greater than the match threshold.

31. The subcutaneous cardiac device of claim 25, wherein the processor is configured to determine, in response to one of the number of beats stored in one of the plurality of subgroups not exceeding the subgroup threshold or a beat of the plurality of beats not being stored in one of the plurality of subgroups, a next plurality of beats in response to the sensed cardiac signal, determine whether to store a beat of the next plurality of beats in a subgroup of the plurality of subgroups, determine whether a number of beats stored in one of the plurality of subgroups exceeds a subgroup threshold, and generate a template in response to the number of beats stored in one of the plurality of subgroups exceeding the subgroup threshold.