WITHIN-PATIENT ALGORITHM TO PREDICT HEART FAILURE DECOMPENSATION

• US 20080157980A1
• Filed: 12/27/2006
• Published: 07/03/2008
• Est. Priority Date: 12/27/2006
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Sachanandani, Haresh G., Sweeney, Robert J., Peterson, Jon, Cazares, Shelley, Stalsberg, Kevin J.
• Granted Patent: US 7,629,889 B2
• Time in Patent Office: Days
• US Class Current: 340/573.1
• CPC Class Codes: A61B 2560/0242 adapted to measure environmental factors, e.g. temperature, pollution
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02455 provided with high/low alarm devices
• CPC Class Codes: A61B 5/076 Permanent implantations telemetry using implanted circuitry A61B5/0031; implanted stimulators for therapy A61N1/3605, A61N1/362, A61N1/372
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• 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 1/37252 Details of algorithms or data aspects of communication system, e.g. handshaking, transmitting specific data or segmenting data
• CPC Class Codes: G16H 40/67 for remote operation
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

This document discusses, among other things, systems and methods for predicting heart failure decompensation using within-patient diagnostics. A method comprises detecting an alert status of each of one or more sensors; calculating an alert score by combining the detected alerts; and calculating a composite alert score, the composite alert score being indicative of a physiological condition and comprising a combination of two or more alert scores.

Claims

1. A method comprising:

detecting an alert status of each of one or more sensors;

calculating an alert score by combining the detected alerts; and

calculating a composite alert score, the composite alert score being indicative of a physiological condition and comprising a combination of two or more alert scores.

2. The method of claim 1, wherein calculating the alert score includes combining detected alerts occurring over time.

8. The method of claim 1, wherein detecting the alert status includes using a threshold value.

9. The method of claim 8, wherein the threshold value includes one of a relative change from a baseline value, an absolute value, or a specified deviation from a baseline value.

10. The method of claim 1, wherein calculating the alert score includes calculating a weighted function of two or more detected alert statuses.

11. The method of claim 10, wherein calculating the weighted function includes using one or more weights, wherein the weights are one of:

equal, unequal, or adaptive.

12. The method of claim 10, wherein calculating the weighted function includes using one or more weights that are related to one or more of:

time, a number or type of the one or more sensors, a patient population, or one or more characteristics of a current patient.

13. The method of claim 1, wherein the composite alert score indicates a likelihood of heart failure decompensation.

14. The method of claim 1, wherein the composite alert score indicates a likelihood of death in a timeframe.

15. The method of claim 1, wherein the composite alert score indicates a likelihood of a change in quality of life in a timeframe.

16. The method of claim 1, wherein calculating the composite alert score includes using a weighted function.

17. The method of claim 1, comprising:

comparing the composite alert score to a composite alert score threshold; and

providing an indication of a higher likelihood of a physiological condition when the composite alert score exceeds the composite alert score threshold.

18. The method of claim 17, comprising:

choosing an initial value for the composite alert score threshold; and

dynamically adjusting the composite alert score threshold to improve one or more performance measures related to false positives or false negatives for a particular patient.

19. The method of claim 18, wherein choosing the initial value includes using a value determined during a learning period.

20. The method of claim 18, wherein adjusting the composite alert score is performed automatically.

21. The method of claim 17, wherein the initial value is set to an artificially high or low value.

22. The method of claim 17, wherein the composite alert score threshold is dynamically adjusted.

3. The method of 1, wherein detecting the alert status includes detecting a discrete value or a binary value.

4. The method of claim 3, wherein the discrete value is indicative of one of two or more states.

5. The method of claim 3, wherein the binary value is indicative of a heart failure decompensation condition or a non-heart failure decompensation condition.

6. The method of claim 3, wherein the binary value is indicative of a higher likelihood of death in a particular timeframe or a lower likelihood of death in the particular timeframe.

7. The method of claim 3, wherein the binary value is indicative of a higher likelihood of a change in quality of life in a particular timeframe or a lower likelihood of a change in quality of life in the particular timeframe.

23. A system comprising:

a patient device comprising;

a communication module adapted to detect an alert status of each of one or more sensors;

an analysis module adapted to;

calculate an alert score by combining the detected alerts; and

calculate a composite alert score, the composite alert score being indicative of a physiological condition and comprising a combination of two or more alert scores.

24. The system of claim 23, wherein calculating the alert score includes combining detected alerts occurring over time.

25. The system of claim 23, comprising a sensor adapted to output a binary value indicative of a heart failure decompensation condition or a non-heart failure decompensation condition.

26. The system of claim 25, wherein the sensor is adapted to set the alert status using a threshold value.

27. The system of claim 26, wherein the threshold value includes one of a relative change from a baseline value, an absolute value, or a specified deviation from a baseline value.

28. The system of claim 23, wherein the analysis module is adapted to calculate the alert score using a weighted function of two or more detected alert statuses.

29. The system of claim 23, wherein the composite alert score indicates a likelihood of heart failure decompensation.

30. The system of claim 23, wherein the composite alert score indicates a likelihood of death in a timeframe.

31. The system of claim 23, wherein the composite alert score indicates a likelihood of a change in quality of life in a timeframe.

32. The system of claim 23, wherein the analysis module is adapted to:

compare the composite alert score to a composite alert score threshold; and

provide an indication of a higher likelihood of a physiological condition when the composite alert score exceeds the composite alert score threshold.

33. An apparatus comprising:

means for detecting an alert status of each of one or more sensors;

means for calculating an alert score by combining the detected alerts; and

means for calculating a composite alert score, the composite alert score being indicative of a physiological condition and comprising a combination of two or more alert scores.