Rapid shallow breathing detection for use in congestive heart failure status determination

• US 7,775,983 B2
• Filed: 09/16/2005
• Issued: 08/17/2010
• Est. Priority Date: 09/16/2005
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Zhang, Yi, Hatlestad, John D., Dalal, Yousufali H., Brockway, Marina
• Primary Examiner(s): Mallari; Patricia C
• Assistant Examiner(s): Toth; Karen E
• Application Number:
  US11/229,316
• Publication Number:
  US 20070073168A1
• Time in Patent Office: 1,796 Days
• Field of Search: 600/483, 600529-543
• US Class Current: 600/483
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/091 Measuring volume of inspired or expired gases, e.g. to determine lung capacity
• CPC Class Codes: A61B 5/411 Detecting or monitoring allergy or intolerance reactions to an allergenic agent or substance
• 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

Abstract

Systems and methods involve use of a medical device comprising sensing circuitry. One or more respiratory parameters are detected using the device. Patient baseline weight is provided, and an output signal indicative of a patient'"'"'s congestive heart failure status is generated based on a change in the one or more respiratory parameters and a change in the patient'"'"'s measured weight or predicted weight relative to the patient baseline weight. The respiratory parameters may include one or more of respiration rate, relative tidal volume, an index indicative of rapid shallow breathing by the patient, an index derived by computing a respiration rate and a tidal volume for each patient breath, and an index indicative of dyspnea, for example.

Claims

1. A method, comprising:

detecting one or more respiratory parameters;

providing patient weight;

providing patient baseline weight; and

generating an output signal indicative of a patient'"'"'s congestive heart failure status based on a change in the one or more respiratory parameters and a change in the patient weight relative to the patient baseline weight, wherein one of the change in the one or more respiratory parameters and the change in patient weight is used to validate the other of the change in the one or more respiratory parameters and the change in patient weight, and the generating is implemented at least in part by circuitry.

2. The method of claim 1, wherein the one or more respiratory parameters comprises respiration rate.

3. The method of claim 1, wherein the one or more respiratory parameters comprises an index indicative of rapid shallow breathing by the patient.

4. The method of claim 3, wherein the index is derived by computing a respiration rate and a tidal volume for each patient breath.

5. The method of claim 1, wherein the one or more respiratory parameters comprises an index indicative of dyspnea.

6. The method of claim 1, wherein the one or more respiratory parameters comprises an index indicative of rapid shallow breathing by the patient, the method further comprising using the index as a basis to triage or discharge the patient.

7. The method of claim 1, wherein generating the output signal comprises generating a perceivable signal indicating a need for clinician intervention or initiation, adjustment or termination of therapy delivery to the patient.

8. The method of claim 1, wherein generating the output signal comprises generating a signal for facilitating automatic initiation, adjustment or termination of therapy delivery to the patient.

9. The method of claim 1, further comprising:

detecting the change in the one or more respiratory parameters;

initiating a computation of a change in the patient weight; and

generating the output signal in response to the change in the one or more respiratory parameters exceeding a first threshold and the computed change in the patient weight exceeding a second threshold.

10. The method of claim 9, wherein the change in the one or more respiratory parameters represents a cumulative change or slope of change in the one or more respiratory parameters.

11. The method of claim 9, further comprising updating the first and second thresholds in response to the detected change in the one or more respiratory parameters exceeding the first threshold and the computed change in the patient weight exceeding the second threshold.

12. The method of claim 1, further comprising:

detecting the change in the one or more respiratory parameters relative to a first threshold; and

predicting the change in patient weight based on the change in the one or more respiratory parameters.

13. The method of claim 12, wherein predicting the change in patient weight comprises:

computing a change in respiration rate based on the change in the one or more respiratory parameters; and

deriving coefficients based on a relationship between change in patient weight relative to change in respiration rate.

14. The method of claim 13, wherein the coefficients are derived from a linear regression of change in patient weight relative to change in respiration rate.

15. The method of claim 13, further comprising:

generating a baseline relationship between change in patient weight relative to change in respiration rate for a patient; and

updating the baseline relationship in response to a change in therapy delivered to the patient or change in patient condition.

16. The method of claim 1, further comprising:

computing a change in respiration rate based on the change in the one or more respiratory parameters relative to a first threshold;

predicting a change in patient weight based on the change in respiration rate; and

generating the output signal in response to the predicted weight change exceeding a second threshold.

17. The method of claim 16, further comprising updating the first and second thresholds in response to the detected change in the one or more respiratory parameters exceeding the first threshold and the predicted weight change exceeding the second threshold.

18. The method of claim 1, wherein generating the output signal is performed at least in part by an implantable medical device.

19. The method of claim 1, wherein generating the output signal is performed at least in part by a patient-external system.

20. The method of claim 1, wherein detecting one or more respiratory parameters comprises detecting the one or more respiratory parameters from within the patient'"'"'s body.

21. A system, comprising:

means for detecting one or more respiratory parameters;

means for providing patient weight;

means for providing patient baseline weight;

means for identifying a change in the patient weight relative to the patient baseline weight; and

means for generating an output signal indicative of a patient'"'"'s congestive heart failure status based on a change in the one or more respiratory parameters and the change in the patient weight relative to the patient baseline weight, wherein one of the change in the one or more respiratory parameters and the change in patient weight is used to validate the other of the change in the one or more respiratory parameters and the change in patient weight.

22. The system of claim 21, comprising means for predicting the change in the patient weight.

23. The system of claim 21, comprising means for indicating a need for clinician intervention or initiation, adjustment or termination of therapy delivery to the patient.

24. The system of claim 21, comprising means for facilitating automatic initiation, adjustment or termination of therapy delivery to the patient.