System and method for generating a trend parameter based on respiration rate distribution

• US 20070073169A1
• Filed: 05/23/2006
• Published: 03/29/2007
• 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, Dalal, Yousufali, Averina, Viktoria
• Granted Patent: US 7,731,663 B2
• Time in Patent Office: Days
• US Class Current: 600/483
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• 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 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/08 Detecting, measuring or recording devices for evaluating the respiratory organs A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/0803 Recording apparatus specially adapted therefor
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• 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
• CPC Class Codes: C07C 17/361 by reactions involving a decrease in the number of carbon atoms
• CPC Class Codes: C07C 19/16 and iodine

Abstract

Systems and methods provide for assessing the heart failure status of a patient and, more particularly, to generating a trend parameter based on a distribution of the patient'"'"'s respiration rate. Systems and methods provide for detecting, using an implantable device or a patient-external device, patient respiration and computing a respiration rate based on the detected patient respiration. A distribution of the respiration rate is calculated, and a trend parameter based on the respiration rate distribution is generated. The trend parameter is indicative of a patient'"'"'s heart failure status. An output signal indicative of the patient'"'"'s heart failure status may be generated based on the trend parameter.

Claims

1. A method, comprising:

detecting patient respiration;

computing a respiration rate based on the detected patient respiration;

calculating a distribution of the respiration rate; and

generating a trend parameter based on the respiration rate distribution.

2. The method of claim 1, wherein detecting patient respiration comprises detecting patient respiration using an implantable device.

3. The method of claim 1, further comprising monitoring one or more of a patient'"'"'s heart failure status, respiratory disease or respiratory disorder based on the trend parameter.

4. The method of claim 1, further comprising generating an output signal indicative of a patient'"'"'s heart failure status based on the trend parameter.

5. The method of claim 1, further comprising predicting patient decompensation episodes using the trend parameter.

6. The method of claim 1, further comprising titrating a patient therapy using the trend parameter.

7. The method of claim 1, wherein the trend parameter characterizes a respiration rate and a burden of rapid shallow breathing of the patient.

8. The method of claim 1, further comprising discriminating between stable heart failure status and decompensated heart failure status of the patient using the trend parameter.

9. The method of claim 1, further comprising displaying one or both of data and graphs of one or more of the trend parameter, respiration rate, and respiration rate distribution.

10. The method of claim 1, wherein calculating the respiration rate distribution comprises generating a histogram from the respiration rate.

11. The method of claim 1, wherein:

calculating the respiration rate distribution comprises generating a histogram from the respiration rate; and

the trend parameter is generated based on areas under a curve of the histogram relative to a respiration rate threshold.

12. The method of claim 1, wherein calculating the respiration rate distribution comprises generating a histogram from the respiration rate, the method further comprising:

providing a user determined or algorithmically determined respiration rate threshold; and

determining a first area under a curve of the histogram that falls below the threshold;

wherein generating the trend parameter comprises calculating a ratio of the first area to a total area under the curve of the histogram.

13. The method of claim 1, wherein calculating the respiration rate distribution comprises generating a histogram from the respiration rate, the method further comprising:

providing a user determined or algorithmically determined respiration rate threshold;

determining a first area under a curve of the histogram that falls below the threshold;

determining a second area under a curve of the histogram that falls above the threshold;

wherein generating the trend parameter comprises calculating a ratio of the first and second areas under the curve of the histogram.

14. The method of claim 1, wherein calculating the respiration rate distribution comprises generating a histogram from the respiration rate, the method further comprising:

providing a measure of characteristic respiration rate for the histogram; and

determining a measure of respiration rate distribution spread;

wherein generating the trend parameter is based on a relationship between the measure of characteristic respiration rate and measure of respiration rate distribution spread.

15. The method of claim 14, further comprising generating a plot of the relationship between the measure of characteristic respiration rate and measure of respiration rate distribution spread.

16. A system, comprising:

a medical device comprising sensing circuitry;

detection circuitry disposed in the medical device and coupled to the sensing circuitry, the detection circuitry configured to detect one or more respiratory parameters; and

a processor coupled to the detection circuitry, the processor configured to calculate a distribution of a respiration rate developed from the one or more respiratory parameters, and generate a trend parameter based on the respiration rate distribution.

17. The system of claim 16, wherein the processor is configured to monitor one or more of a patient'"'"'s heart failure status, respiratory disease or respiratory condition based on the trend parameter.

18. The system of claim 16, wherein the medical device comprises an implantable housing, and the sensing circuitry and detection circuitry are disposed in the implantable housing.

19. The system of claim 16, wherein the medical device comprises a patient-external housing, and the sensing circuitry and detection circuitry are disposed in the patient-external housing.

20. The system of claim 16, wherein the processor comprises a processor of a networked patient management system.

21. The system of claim 16, wherein the processor comprises a processor of a programmer or a portable communicator.

22. The system of claim 16, wherein the sensing circuitry comprises at least one of a transthoracic impedance sensor and a minute ventilation sensor.

23. The system of claim 16, wherein the sensing circuitry comprises one or both of an accelerometer and a pressure sensor.

24. A system, comprising:

means for detecting patient respiration;

means for computing a respiration rate based on the detected patient respiration;

means for calculating a distribution of the respiration rate; and

means for generating a trend parameter based on the respiration rate distribution.

25. The system of claim 24, wherein the respiration detecting means comprises means for detecting patient respiration from within a patient.