Blending cardiac rhythm detection processes

• US 20060217621A1
• Filed: 03/24/2005
• Published: 09/28/2006
• Est. Priority Date: 03/24/2005
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Kim, Jaeho, Bocek, Joseph M., Lovett, Eric G., Thompson, Julie A.
• Granted Patent: US 7,818,056 B2
• Time in Patent Office: Days
• US Class Current: 600/509
• CPC Class Codes: A61B 5/35 by template matching
• 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 1/3925 Monitoring; Protecting
• CPC Class Codes: A61N 1/395 for treating atrial fibrillation
• CPC Class Codes: A61N 1/39622 Pacing therapy
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

Systems and methods are described for classifying a cardiac rhythm. A cardiac rhythm is classified using a classification process that includes a plurality of cardiac rhythm discriminators. Each rhythm discriminator provides an independent classification of the cardiac rhythm. The classification process is modified if the modification is likely to produce enhanced classification results. The rhythm is reclassified using the modified classification process.

Claims

1. A method for classifying a cardiac rhythm, comprising:

classifying the cardiac rhythm using a classification process comprising a plurality of cardiac rhythm discriminators, each rhythm discriminator providing an independent classification of the cardiac rhythm;

determining if modifying the classification process is likely to enhance classification;

modifying the classification process if the classification is likely to be enhanced; and

reclassifying the cardiac rhythm using the modified classification process.

2. The method of claim 1, further comprising classifying the cardiac rhythm based on results of the plurality of rhythm discriminators if modifying the classification process is not likely to enhance classification.

3. The method of claim 1, wherein determining if the cardiac rhythm classification is likely to be enhanced comprises determining if two of more of the plurality of rhythm discriminators produce conflicting results.

4. The method of claim 1, wherein determining if the cardiac rhythm classification is likely to be enhanced comprises determining if at least one of the plurality of rhythm discriminators produces indeterminate results.

5. The method of claim 1, wherein classifying the cardiac rhythm comprises classifying the cardiac rhythm using at least one morphology-based rhythm discriminator.

6. The method or claim 5, wherein classifying the cardiac rhythm using the at least one morphology-based discriminator comprises comparing a morphology of one or more cardiac beats of the cardiac rhythm to a morphology template.

7. The method of claim 1, wherein classifying the cardiac rhythm comprises classifying the cardiac rhythm using at least one interval-based rhythm discriminator.

8. The method of claim 7, wherein classifying the cardiac rhythm using the at least one interval-based rhythm discriminator comprises classifying the cardiac rhythm based on a relationship between an atrial rate and a ventricular rate of the cardiac rhythm.

9. The method of claim 1, wherein modifying the classification process comprises modifying one or more parameters of at least one of the plurality of rhythm discriminators.

10. The method of claim 1, wherein:

modifying the classification process comprises acquiring sensor information associated with the patient'"'"'s metabolic requirements; and

reclassifying the cardiac rhythm comprises reclassifying the cardiac rhythm using the acquired sensor information.

11. The method of claim 1, wherein:

modifying the classification process comprises classifying the cardiac rhythm using one or more supplemental cardiac rhythm discriminators; and

reclassifying the cardiac rhythm comprises reclassifying the cardiac rhythm using classification results from the one or more supplemental rhythm discriminators.

12. The method of claim 1, wherein modifying the classification process comprises modifying a first parameter of a first rhythm discriminator based on a second parameter of a second rhythm discriminator.

13. The method of claim 1, further comprising delivering or withholding therapy based on the reclassification of the cardiac rhythm.

14. A cardiac device, comprising:

a sensing circuit configured to sense cardiac signals associated with a cardiac rhythm;

a plurality of independent rhythm discriminators configured to classify the cardiac rhythm; and

a classification processor coupled to the independent rhythm discriminators, the classification processor configured to implement a classification process to classify the cardiac rhythm, the classification process based on results of the independent rhythm discriminators, the classification processor further configured to determine if modification of the classification process is likely to enhance rhythm classification and to modify the classification process if the rhythm classification is likely to be enhanced, the classification processor further configured to reclassify the cardiac rhythm using the modified classification process.

15. The cardiac device of claim 14, wherein the classification processor is configured to determine that the classification is likely to be enhanced if results of at least two of the plurality of independent rhythm discriminators conflict.

16. The cardiac device of claim 14, wherein the classification processor is configured to determine that the classification is likely to be enhanced if results of at least one of the plurality of independent rhythm discriminators is indeterminate.

17. The cardiac device of claim 14, wherein at least one of the plurality of independent rhythm discriminators comprises a morphology-based discriminator.

18. The cardiac device of claim 14, wherein at least one of the plurality of independent rhythm discriminators comprises an interval-based discriminator.

19. The cardiac device of claim 14, wherein at least one of the plurality of independent rhythm discriminators is configured to classify the cardiac rhythm based on a relationship between an atrial rate and a ventricular rate of the cardiac rhythm.

20. The cardiac device of claim 14, wherein the classification process is configured to modify a parameter of at least one of the plurality of rhythm discriminators.

21. The cardiac device of claim 14, further comprising a metabolic sensor configured to determine information associated with a patient'"'"'s metabolic need, wherein the classification processor is configured to use the metabolic information to modify the classification process.

22. The cardiac device of claim 14, further comprising one or more supplemental rhythm discriminators configured to classify the cardiac rhythm, wherein the classification processor is configured to use results of the one or more supplemental rhythm discriminators to modify the classification process.

23. The cardiac device of claim 14, wherein the classification processor is configured to modify a first parameter of a first rhythm discriminator based on a second parameter of a second rhythm discriminator.

24. The cardiac device of claim 14, further comprising a therapy delivery unit coupled to the classification processor, the therapy delivery unit configured to deliver or withhold therapy based on the reclassification of the cardiac rhythm.

25. A device for classifying a cardiac rhythm, comprising:

means for classifying the cardiac rhythm using a classification process comprising a plurality of cardiac rhythm discriminators, each rhythm discriminator providing an independent classification of the cardiac rhythm;

means for determining if modifying the classification process is likely to enhance classification;

means for modifying the classification process if the classification is likely to be enhanced; and

means for reclassifying the cardiac rhythm using the modified classification process.

26. The device of claim 25, further comprising means for determining if two of more of the plurality of rhythm discriminators produce conflicting results.

27. The device of claim 25, further comprising means for determining if at least one of the plurality of rhythm discriminators produces indeterminate results.

28. The device of claim 25, further comprising means for delivering or withholding therapy based on the reclassification of the cardiac rhythm.