Method and apparatus for monitoring heart failure patients with cardiopulmonary comorbidities

• US 20090132000A1
• Filed: 01/08/2009
• Published: 05/21/2009
• Est. Priority Date: 07/23/2004
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Kadhiresan, Veerichetty, Carlson, Gerrard M., Hopper, Donald, Brockway, Marina, Beck, Kenneth
• Granted Patent: US 8,065,010 B2
• Time in Patent Office: Days
• US Class Current: 607/18
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/4878 Evaluating oedema
• 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

A system receives signals indicative of cardiopulmonary conditions sensed by a plurality of sensors and provides for monitoring and automated differential diagnosis of the cardiopulmonary conditions based on the signals. Cardiogenic pulmonary edema is detected based on one or more signals sensed by implantable sensors. If the cardiogenic pulmonary edema is not detected, obstructive pulmonary disease and restrictive pulmonary disease are each detected based on a forced vital capacity (FVC) parameter and a forced expiratory volume (FEV) parameter measured from a respiratory signal sensed by an implantable or non-implantable sensor. In one embodiment, an implantable medical device senses signals indicative of the cardiopulmonary conditions, and an external system detects the cardiopulmonary conditions based on these signals by executing an automatic detection algorithm.

Claims

1. A system, comprising:

an implantable medical device including;

one or more sensors adapted to sense one or more signals indicative of a plurality of cardiopulmonary conditions;

an implant processor, coupled to the one or more sensors, to process the one or more signals; and

an implant telemetry module, coupled to the implant processor, to transmit the processed one or more signals; and

an external system communicatively coupled to the implantable medical device via telemetry, the external system including;

an external telemetry module to receive the processed one or more signals; and

an external processor coupled to the external telemetry module, the external processor including a cardiopulmonary condition detector adapted to detect the plurality of cardiopulmonary conditions based on the processed one or more signals, the cardiopulmonary condition detector including at least a cardiogenic pulmonary edema detector, an obstructive pulmonary disease detector, and a restrictive pulmonary disease detector.

2. The system of claim 1, wherein the implantable medical device comprises an implantable cardiac rhythm management (CRM) device.

3. The system of claim 1, wherein the external system comprises a programmer.

4. The system of claim 1, wherein the external system comprises a patient management system including:

an external device communicatively coupled to the implantable medical device;

a telecommunication network coupled to the external device; and

a remote device, coupled to the telecommunication network, to allow access to the implantable medical device from a remote location.

5. The system of claim 4, wherein the remote device comprises the cardiopulmonary condition detector.

6. The system of claim 5, wherein the cardiopulmonary condition detector comprises a dyspnea detector adapted to detect dyspnea based on at least one dyspnea-indicating signal of the processed one or more signals, and wherein the pulmonary edema detector is adapted to detect a cardiogenic pulmonary edema after the dyspnea is detected.

7. The system of claim 5, wherein the one or more sensors comprise a sensing circuit to sense one or more electrograms, and the implant processor comprises a heart rate variability (HRV) processor adapted to measure an HRV from the one or more electrograms and adapted to produce one or more parameters indicative of cardiogenic pulmonary edema based on the HRV.

8. The system of claim 1, wherein the one or more sensors comprise an impedance sensor to sense a thoracic impedance, and the implant processor comprises an impedance processor adapted to produce one or more parameters indicative of cardiogenic pulmonary edema based on the thoracic impedance.

9. The system of claim 1, wherein the one or more sensors comprise a heart sound sensor to sense a heart sound signal indicative of at least third heart sounds (S3), and the implant processor comprises an S3 processor adapted to detect occurrences of S3 and adapted to produce one or more parameters indicative of cardiogenic pulmonary edema based on the detected occurrences of S3.

10. The system of claim 1, wherein the obstructive pulmonary disease detector is adapted to detect an obstructive pulmonary disease based on a forced vital capacity (FVC) parameter and a forced expiratory volume (FEV) parameter, and the restrictive pulmonary disease detector is adapted to detect a restrictive pulmonary disease based on the FVC parameter and the FEV parameter.

11. The system of claim 10, wherein the cardiopulmonary condition detector further comprises a low FVC detector, coupled to the pulmonary edema detector, to detect a low FVC when the FVC parameter is less than a predetermined threshold FVC parameter value if the cardiogenic pulmonary edema is not detected, and wherein the obstructive pulmonary disease detector is adapted to detect the obstructive pulmonary disease if the low FVC is detected, and the restrictive pulmonary disease detector is adapted to detect the restrictive pulmonary disease if the low FVC is detected.

12. The system of claim 10, further comprising an external spirometer, coupled to the external system, to sense a spirometry signal indicative of lung volume, and wherein the external processor comprises:

an FVC measurement module adapted to measure the FVC parameter from the spirometry signal; and

an FEV measurement module adapted to measure the FEV parameter from the spirometry signal.

13. The system of claim 10, wherein the one or more sensors comprise an impedance sensor to sense an impedance signal indicative of minute ventilation, and the external processor comprises:

an FVC measurement module adapted to measure the FVC parameter from the impedance signal; and

an FEV measurement module adapted to measure the FEV parameter from the impedance signal.

14. The system of claim 13, wherein the one or more sensors further comprise an activity sensor to sense an activity signal indicative of a physical activity level, and wherein:

the FVC measurement module is adapted to measure the FVC parameter from the MV impedance signal when the activity signal indicates a substantially resting state; and

the FEV measurement module is adapted to measure the FEV parameter from the MV impedance signal when the activity signal indicates a substantially resting state.

15. A system, comprising:

an implantable medical device including;

means for sensing one or more signals indicative of a plurality of cardiopulmonary conditions;

means for processing the one or more signals; and

means for transmitting the processed one or more signals; and

an external system adapted to be communicatively coupled to the implantable medical device via telemetry, the external system including;

means for receiving the processed one or more signals; and

means for detecting the plurality of cardiopulmonary conditions using the processed one or more signals, the plurality of cardiopulmonary conditions including at least cardiogenic pulmonary edema, obstructive pulmonary disease, and restrictive pulmonary disease.

16. The system of claim 15, wherein the means for sensing comprises means for sensing one or more electrograms indicative of heart rate variability (HRV), and the means for detecting the plurality of cardiopulmonary conditions comprises means for detecting the plurality of cardiopulmonary conditions using at least one or more HRV parameters produced using the one or more electrograms.

17. The system of claim 15, wherein the means for sensing comprises means for sensing a heart sound signal indicative of at least third heart sounds (S3), and the means for detecting the plurality of cardiopulmonary conditions comprises means for detecting the plurality of cardiopulmonary conditions using at least one or more heart sound parameters produced using the heart sound signal.

18. The system of claim 15, wherein the means for sensing comprises means for sensing a thoracic impedance, and the means for detecting the plurality of cardiopulmonary conditions comprises means for detecting the plurality of cardiopulmonary conditions using at least one or more impedance parameters produced using the thoracic impedance.

19. The system of claim 18, wherein the means for detecting the plurality of cardiopulmonary conditions comprises:

means for producing a minute ventilation (MV) impedance signal based on the thoracic impedance, the MV impedance signal indicative of minute ventilation; and

means for measuring a force vital capacity (FVC) parameter and a forced expiratory volume (FEV) parameter from the MV impedance signal.

20. The system of claim 15, wherein the means for sensing comprises means for sensing one or more signals indicative of dyspnea, and the means for detecting the plurality of cardiopulmonary conditions comprises means for detecting dyspnea and detecting the cardiogenic pulmonary edema after the dyspnea is detected.