Cardiac response classification using multisite sensing and pacing

• US 9,308,375 B2
• Filed: 09/05/2014
• Issued: 04/12/2016
• Est. Priority Date: 12/12/2003
• Status: Active Grant

• Current Assignee: Divergent Technologies, Inc.
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Kim, Jaeho, Bocek, Joseph M., Meyer, Scott A., Haefner, Paul A., Sih, Haris
• Primary Examiner(s): Holmes, Rex R
• Application Number:
  US14/478,596
• Publication Number:
  US 20150051662A1
• Time in Patent Office: 585 Days
• Field of Search: 607/9, 607 26- 28, 600/510
• US Class Current: 1/1
• CPC Class Codes: A61B 5/35 by template matching
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker
• 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 1/368 comprising more than one electrode co-operating with different heart regions A61N1/3622, A61N1/3627 take precedence
• CPC Class Codes: A61N 1/371 Capture, i.e. successful stimulation
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

Methods and devices for classifying a cardiac pacing response involve using a first electrode combination for pacing and a second electrode combination for sensing a cardiac signal following pacing. The cardiac response to pacing may be classified using the sensed cardiac signal. One process involves using the sensed cardiac signal to detect the cardiac response as a fusion/pseudofusion beat. Another process involves using the sensed cardiac signal to classify the cardiac response to pacing as one of at least three cardiac response types.

Claims

1. A method of determining a cardiac response to a pacing pulse, comprising:

delivering two or more initialization pacing pulses to a heart using a first electrode combination of a plurality of electrodes that are electrically coupled to the heart, wherein the two or more initialization pacing pulses are provided at a pacing energy that is sufficient to result in capture of the heart;

sensing for a cardiac response following each of the two or more initialization pacing pulses using a second electrode combination;

for each of the two or more initialization pacing pulses, determining a delay interval between when an initialization pacing pulse was delivered using the first electrode combination until when a corresponding cardiac response was sensed using the second electrode combination;

following delivery of the two or more initialization pacing pulses;

delivering a pacing pulse to the heart using the first electrode combination;

sensing a cardiac response to the pacing pulse using the second electrode combination;

positioning a classification window according to a predetermined signal template morphology feature, wherein the positioning includes beginning the classification window a predetermined time delay following the pacing pulse, wherein the time delay is predetermined using the determined delay interval of the two or more initialization pulses; and

classifying the cardiac response to the pacing pulse as one of a captured response and a non-captured response, the classifying step including;

determining if the sensed cardiac response to the pacing pulse includes the predetermined signal morphology feature within the classification window.

2. The method of claim 1, wherein the predetermined time delay is chosen by combining the determined delay intervals of each of the two or more initialization pacing pulses.

3. The method of claim 1, wherein determining if the sensed cardiac response to the pacing pulse has a predetermined characteristic that falls within a classification window comprises determining if the sensed cardiac response to the pacing pulse has a predetermined characteristic that falls within a first portion of a classification window or a second portion of the classification window.

4. The method of claim 2, wherein the combining step includes averaging the delay intervals of the two or more initialization pacing pulses.

5. The method of claim 1, wherein the two or more initialization pacing pulses are sequential pacing pulses.

6. The method of claim 1, wherein:

prior to delivering the pacing pulse, generating a template that is based, at least in part, on the determined delay intervals of each of the two or more initialization pacing pulses; and

after delivering the pacing pulse, the predetermined time delay is based on the previously generated temp late.

7. The method of claim 1, wherein the classification window represents a time interval that follows the pacing pulse, and wherein the time interval includes a time that the predetermined characteristic of the sensed cardiac response is expected to occur.

8. The method of claim 7, wherein the classification window represents a time interval that includes a first amount of time before the time that the predetermined characteristic of the sensed cardiac response is expected to occur and a second amount of time after the time that the predetermined characteristic of the sensed cardiac response is expected to occur.

9. The method of claim 8, wherein the second amount of time is about 20 ms.

10. The method of claim 1, wherein the predetermined signal morphology is identified using a cardiac signal morphology template.

11. The method of claim 1, wherein the classifying step includes classifying the cardiac response to the pacing pulse as one of a captured response, a non-captured response and a fusion response.

12. The method of claim 1, further comprising:

detecting a level of noise in the cardiac response; and

selectively canceling the classification of the cardiac response based on the level of detected noise.

13. The method of claim 1, wherein:

delivering the pacing pulse to the heart using the first electrode combination comprises delivering the pacing pulse using a near-field vector; and

sensing the cardiac response following the pacing pulse using the second electrode combination comprises sensing the cardiac response using a far-field vector.

14. The method of claim 1, wherein:

delivering the pacing pulse to the heart comprises delivering the pacing pulse to one ventricle using the first electrode combination; and

sensing the cardiac response following the pacing pulse comprises sensing the cardiac response using at least one electrode disposed in the other ventricle.

15. The method of claim 1, wherein:

delivering the pacing pulse to the heart comprises delivering the pacing pulse to an atrium using the first electrode combination; and

sensing the cardiac response following the pacing pulse comprises sensing the cardiac response using the second electrode combination.

16. The method of claim 1, wherein:

delivering the pacing pulse to the heart comprises delivering the pacing pulse to one atrium using the first electrode combination; and

sensing the cardiac response following the pacing pulse comprises sensing the cardiac response using at least one electrode disposed in the other atrium.

17. A method of determining a cardiac response to a pacing pulse, comprising:

for each of two or more initialization pacing pulses, determining a delay interval between when an initialization pacing pulse was delivered using a first electrode combination and a corresponding cardiac response sensed using a second electrode combination, wherein the two or more initialization pacing pulses are provided at a pacing energy that is sufficient to result in capture of the heart;

identifying a predetermined time delay that is based, at least in p art, on the determined delay intervals of the two or more initialization pacing pulses;

following delivery of the two or more initialization pacing pulses;

delivering a pacing pulse to the heart using the first electrode combination;

sensing a cardiac response to the pacing pulse using the second electrode combination; and

classifying the cardiac response to the pacing pulse as one of a captured response and a non-captured response, the classifying step including;

determining if the sensed cardiac response has a predetermined characteristic that falls within a first period of time while sensing using the second electrode combination or within a second period of time while sensing using the second electrode combination, wherein the second period of time is after the first period of time, wherein the predetermined characteristic comprises a predetermined signal morphology identified using a cardiac signal morphology template, and wherein the first period of time begins after the predetermined time delay following the pacing pulse and extends for a predefined duration.

18. The method of claim 17, wherein the predetermined time delay is chosen by combining the determined delay intervals of each of the two or more initialization pacing pulses.

19. A medical device, comprising:

a plurality of electrodes configured to be coupled to a heart;

a pulse delivery circuit configured to deliver a pacing pulse to the heart via two or more of the plurality of electrodes;

a sensing circuit configured to sense a cardiac response for cardiac response classification following the pacing pulse via two or more of the plurality of electrodes;

a control circuit, the control circuit operatively coupled to the sensing circuit and configured to classify the cardiac response to the pacing pulse as one of a captured response and a non-captured response by determining if the sensed cardiac response has a predetermined signal morphology that is identifiable using a cardiac signal morphology template that falls within a first portion of a classification window or a second portion of the classification window, wherein the classification window begins after a predetermined time delay following the pacing pulse and extends for a window duration;

wherein before the pulse delivery circuit delivers the pacing pulse to the heart,

the control circuit causes the pulse delivery circuit to provide two or more initialization pacing pulses to the heart, wherein the sensing circuit senses for a cardiac response following each of the two or more initialization pacing pulses;

for each of the two or more initialization pacing pulses, the control circuit is configured to determine a delay interval between when the initialization pacing pulse was provided until when a corresponding cardiac response was sensed; and

wherein the control circuit is further configured to establish the predetermined time delay based, at least in part, on the delay intervals of at least two of the two or more initialization pacing pulses.

20. The medical device of claim 19, wherein the predetermined time delay is established by combining the delay intervals of at least two of the two or more initialization pacing pulses.