Detection of heart failure decompensation based on cumulative changes in sensor signals

• US 20070142732A1
• Filed: 12/20/2005
• Published: 06/21/2007
• Est. Priority Date: 12/20/2005
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Brockway, Marina, Troiani, John
• Granted Patent: US 7,761,158 B2
• Time in Patent Office: Days
• US Class Current: 600/508
• 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 1/36521 the parameter being derived from measurement of an electrical impedance
• CPC Class Codes: A61N 1/39622 Pacing therapy

Abstract

Systems, devices and methods provide for evaluation of heart failure symptoms. Sensor data associated with one or more symptoms of heart failure are acquired and trended. Statistical features, such as slope, are extracted from the data trend in a moving window and are used to develop a cumulative sum. The cumulative sum is compared to a threshold value or V-mask to detect a shift in cumulative sum indicating changes in heart failure symptoms. A shift beyond the threshold value may trigger an alert or implementation of therapy.

Claims

1. A method, comprising:

acquiring sensor data associated with one or more symptoms of heart failure;

developing a cumulative sum using the sensor data; and

evaluating the one or more heart failure symptoms based on the cumulative sum.

2. The method of claim 1, wherein acquiring the sensor data comprises:

generating a transthoracic impedance signal; and

extracting statistical features from the transthoracic impedance signal.

3. The method of claim 1, wherein acquiring the sensor data comprises:

acquiring heart sounds data; and

extracting statistical features from the heart sounds data

4. The method of claim 1, wherein acquiring the sensor data comprises:

acquiring patient activity data; and

extracting statistical features from the patient activity data.

5. The method of claim 1, wherein acquiring the sensor data comprises:

acquiring heart rate variability data; and

extracting statistical features from the heart rate variability data.

6. The method of claim 1, wherein acquiring the sensor data comprises:

acquiring apnea/hypopnea index data; and

extracting statistical features from the apnea/hypopnea index data.

7. The method of claim 1, wherein the acquired sensor data comprises data associated with one or more cardiac parameters.

8. The method of claim 1, wherein acquiring the sensor data comprises acquiring data from a single sensor.

9. The method of claim 1, wherein:

acquiring the sensor data comprises acquiring the sensor data from multiple sensors; and

developing the cumulative sum comprises developing a multivariate cumulative sum.

10. The method of claim 1, acquiring the sensor data comprises acquiring the sensor data based on signals sensed within a moving time window.

11. The method of claim 1, wherein developing the cumulative sum comprises:

trending the sensor data in a moving window;

determining a slope of the sensor data trended in the moving window; and

developing the cumulative sum using the slope.

12. The method of claim 1, further comprising:

detecting a shift in the cumulative sum; and

generating a status alert based on the shift.

13. The method of claim 1, further comprising controlling a therapy based on the evaluation of the one or more heart failure symptoms.

14. The method of claim 1, wherein at least one of acquiring the sensor data, developing the cumulative sum, and evaluating the one or more heart failure symptoms are performed at least in part implantably.

15. A medical device, comprising:

sensing circuitry configured to acquire sensor data associated with one or more symptoms of heart failure; and

a diagnostics processor configured to develop a cumulative sum using the sensor data and to evaluate the one or more heart failure symptoms based on the cumulative sum.

16. The medical device of claim 15, wherein the sensing circuitry comprises a sensor configured to sense transthoracic impedance, the sensing circuitry configured to acquire the sensor data based on the transthoracic impedance signal.

17. The medical device of claim 15, wherein at least one of the sensing circuitry and the diagnostics processor comprises an implantable component.

18. The medical device of claim 15, wherein the diagnostics processor is configured to extract statistical features from the sensor data and to develop the cumulative sum using the extracted statistical features.

19. The medical device of claim 15, wherein the diagnostics processor is configured to trend the sensor data, determine a slope of the trend, and develop the cumulative sum using the slope.

20. The medical device of claim 15, wherein the medical device further comprises an alarm unit coupled to the diagnostics processor, the diagnostics processor is configured to detect a shift in the cumulative sum, and the alarm unit is configured issue an alert when the shift exceeds a specified threshold.

21. The medical device of claim 15, wherein the medical device further comprises a therapy control unit coupled to the diagnostics processor, the therapy control unit used to control a therapy based on the evaluation of the one or more heart failure symptoms.

22. The medical device of claim 21, wherein the therapy comprises a cardiac pacing therapy.

23. A medical system, comprising:

means for acquiring sensor data associated with one or more symptoms of heart failure;

means for developing a cumulative sum using the sensor data; and

means for evaluating the one or more heart failure symptoms based on the cumulative sum.

24. The system of claim 23, further comprising:

means for generating a respiration signal; and

means for extracting statistical features from the respiration signal.

25. The system of claim 23, further comprising:

means for detecting a shift in the cumulative sum; and

means for generating a status alert based on the shift.

26. The system of claim 23, further comprising means for controlling a therapy based on the evaluation of the one or more heart failure symptoms.

27. The system of claim 26, wherein the therapy is biventricular pacing.