RESPIRATION MONITORING FOR HEART FAILURE USING IMPLANTABLE DEVICE

• US 20080039730A1
• Filed: 08/08/2006
• Published: 02/14/2008
• Est. Priority Date: 08/08/2006
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Kwok, Jonathan, Lee, Kent, Ni, Quan, Pu, Yachuan
• Granted Patent: US 8,226,570 B2
• Time in Patent Office: Days
• US Class Current: 600/484
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• 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

An implantable respiration monitor can be used to detect disordered breathing or periodic breathing events that can be categorized, such as according to one or more of sleep, exercise, and resting awake states. The categorized frequency of such events can be compared to independently specifiable thresholds, such as to trigger an alert or responsive therapy, or to display one or more trends. The information can also be combined with detection of one or more other congestive heart failure (CHF) symptoms to generate a CHF status indicator or to trigger an alarm or responsive therapy or to display one or more trends. The alert can notify the patient or a caregiver, such as via remote monitoring. The sleep state information can be further categorized according to central sleep apnea (CSA) or obstructive sleep apnea (OSA) events.

Claims

1. A system comprising:

a sleep detector, adapted to detect a sleep indication in a subject, the sleep indication providing an indication or inference of whether the subject is asleep or awake;

an exercise detector, adapted to detect an exercise indication in the subject, the exercise indication providing an indication or inference of whether the subject is active or at rest; and

an implantable respiration monitor, operatively coupled to the sleep and exercise detectors, the respiration monitor adapted to detect disordered breathing in the subject, and to compute at least two of;

a sleep disordered breathing indication, an exercise disordered breathing indication, and a resting awake disordered breathing indication.

2. The system of claim 1, comprising an alert module, operatively coupled to the respiration monitor, the alert module generating an alert in response to an abnormal value of at least one of:

the sleep disordered breathing indication, the exercise disordered breathing indication, and the resting awake disordered breathing indication.

3. The system of claim 2, comprising an ambulatory therapy module, operatively coupled to the alert module, the ambulatory therapy module configured to automatically initiate or adjust therapy in response to the alert.

4. The system of claim 1, comprising an alert module, operatively coupled to the respiration monitor, the alert module generating an alert in response to at least a specified increase in at least one of the sleep disordered breathing indication, the exercise disordered breathing indication, and the resting awake disordered breathing indication.

5. The system of claim 4, comprising an ambulatory therapy module, operatively coupled to the alert module, the ambulatory therapy module configured to automatically initiate or adjust therapy in response to the alert.

6. The system of claim 1, comprising an alert module, operatively coupled to the respiration monitor, the alert module generating an alert in response to at least an abnormal value or a specified increase in at least two of:

the sleep disordered breathing indication, the exercise disordered breathing indication, and the resting awake disordered breathing indication.

7. The system of claim 6, comprising an ambulatory therapy module, operatively coupled to the alert module, the ambulatory therapy module configured to automatically initiate or adjust therapy in response to the alert.

8. The system of claim 1, comprising:

an auxiliary congestive heart failure (CHF) indication detector; and

an alert module, operatively coupled to the respiration monitor and the auxiliary CHF indication detector, the alert module generating an alert in response to an indication of CHF received from the CHF indication detector and an abnormal value or a specified increase of at least one of;

the sleep disordered breathing indication, the exercise disordered breathing indication, and the resting awake disordered breathing indication.

9. The system of claim 8, in which the auxiliary CHF indication detector includes a pulmonary fluid status indicator, and in which the indication of CHF received from the CHF indication detector includes an indication of an abnormally high level of pulmonary fluid.

10. The system of claim 8, in which the auxiliary CHF indication detector includes at least one of a pulmonary artery pressure sensor, a heart sound sensor, a heart rate variability detector, a patient weight indicator, and a patient activity detector.

11. The system of claim 8, comprising an ambulatory therapy module, operatively coupled to the alert module, the ambulatory therapy module configured to automatically initiate or adjust therapy in response to the alert.

12. The system of claim 1, wherein the respiration monitor comprises:

a respiration detector circuit, adapted to detect a respiration signal from the subject;

an envelope detector circuit, adapted to detect an envelope of the respiration signal; and

an envelope variation detector circuit, adapted to detect a variation in the envelope representing disordered breathing.

13. The system of claim 1, wherein the respiration monitor comprises:

means for detecting a respiration signal from the subject; and

means for detecting separate indications of periodic breathing in each of sleep, exercise, and resting awake states.

14. The system of claim 1, including an external display configured to display information about at least one of a sleep disordered breathing indication, an exercise disordered breathing indication, and a resting awake disordered breathing indication.

15. The system of claim 1, in which the display is configured to display a trend over time of at least one of a sleep disordered breathing indication, an exercise disordered breathing indication, and a resting awake disordered breathing indication.

16. The system of claim 1, including:

an apnea classifier, configured to distinguish between obstructive sleep apnea (OSA) and central sleep apnea (CSA); and

wherein the sleep disordered breathing indication uses information from the apnea classifier to determine the sleep disordered breathing indication.

17. A method comprising:

monitoring respiration of a subject;

detecting sleep of the subject;

detecting exercise of the subject; and

determining at least two of a sleep disordered breathing indication, an exercise disordered breathing indication and a resting awake disordered breathing indication.

18. The method of claim 17, comprising generating an alert in response to an abnormal value of at least one of:

the sleep disordered breathing indication, the exercise disordered breathing indication, and the resting awake disordered breathing indication.

19. The method of claim 18, comprising automatically delivering a therapy in response to the alert.

20. The system of claim 17, comprising monitoring an auxiliary indication of congestive heart failure of the subject, and generating an alert in response to an abnormal value of the auxiliary indication of congestive heart failure and an abnormal value of at least one of:

the sleep disordered breathing indication, the exercise disordered breathing indication, and the resting awake disordered breathing indication.

21. The system of claim 20, in which the monitoring an auxiliary indication of congestive heart failure includes monitoring at least one of a pulmonary fluid accumulation, a pulmonary artery pressure, a heart sound, a heart rate variability, a patient weight, and a patient activity level.

22. The system of claim 20, comprising automatically delivering a therapy in response to the alert.

23. The method of claim 17, comprising determining a sleep disordered breathing indication, an exercise disordered breathing indication and a resting awake disordered breathing indication.

24. The method of claim 23, comprising generating an alert in response to an abnormal value or a specified increase of at least two of the sleep disordered breathing indication, the exercise disordered breathing indication, and the resting awake disordered breathing indication.

25. The method of claim 24, comprising automatically delivering a therapy in response to the alert.

26. The method of claim 17, comprising displaying information about at least one of a sleep disordered breathing indication, an exercise disordered breathing indication, and a resting awake disordered breathing indication.

27. The method of claim 17, comprising:

detecting one or more apnea events;

classifying the one or more apnea events as obstructive sleep apnea (OSA) or central sleep apnea (CSA); and

determining the sleep disordered breathing indication using information about the classification of the one or more apnea events as OSA or CSA.

28. The method of claim 27, comprising determining a first sleep disordered breathing indication using only CSA events.

29. The method of claim 28, comprising determining a second sleep disordered breathing indication using only OSA events.