Sleep state classification

• US 8,192,376 B2
• Filed: 08/18/2003
• Issued: 06/05/2012
• Est. Priority Date: 08/18/2003
• Status: Expired due to Fees

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Lovett, Eric G., Sweeney, Robert J., Kenknight, Bruce H.
• Primary Examiner(s): Hindenburg, Max
• Assistant Examiner(s): NGUYEN, HUONG Q
• Application Number:
  US10/643,006
• Publication Number:
  US 20050043652A1
• Time in Patent Office: 3,214 Days
• Field of Search: 600/546, 600/586, 600/595, 600/587
• US Class Current: 600/595
• CPC Class Codes: A61B 2560/0468 Built-in electrodes
• CPC Class Codes: A61B 5/00 Measuring for diagnostic purposes radiation diagnosis A61B6/00; diagnosis by ultrasonic, sonic or infrasonic waves A61B8/00; Identification of persons
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/1116 Determining posture transitions
• CPC Class Codes: A61B 5/1135 by monitoring thoracic expansion
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: A61B 5/398 Electrooculography [EOG], e.g. detecting nystagmus; Electroretinography [ERG]
• CPC Class Codes: A61B 5/4809 Sleep detection, i.e. determining whether a subject is asleep or not
• CPC Class Codes: A61B 5/4812 Detecting sleep stages or cycles
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61B 5/7267 involving training the classification device
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

Systems and methods for sleep state classification involve detecting conditions related to sleep, including at least one condition associated with rapid eye movement (REM) sleep. Additionally, a condition modulated by the sleep-wake status of the patient may be detected. A medical system that is partially or fully implantable incorporates sensors and circuitry for detecting and processing the sleep-related signals. A sleep state processor classifies the patient'"'"'s sleep state based on the sleep-related signals. Sleep state classification may be used in connection with the delivery of sleep state appropriate therapy, diagnostic testing, or patient monitoring.

Claims

1. A method of providing therapy to a patient, comprising:

sensing a condition associated with a sleep-wake status of a patient;

detecting the sleep-wake status based on the sensed condition;

sensing pectoral muscle tone using a sensor disposed on a cardiac rhythm management device implanted in a pectoral region of the patient;

detecting REM sleep status based on the pectoral muscle tone of the patient;

classifying one or more sleep states based on the sleep-wake status and the REM sleep status, wherein the classifying, the detecting the sleep-wake status, and the detecting REM sleep status are performed at least in part implantably; and

providing sleep state informed therapy to the patient using the sleep state classification.

2. The method of claim 1, wherein sensing the muscle tone includes sensing the muscle tone using an electromyogram sensor.

3. The method of claim 1, wherein sensing the muscle tone includes sensing the muscle tone using a sensor on a header of the cardiac rhythm management device.

4. The method of claim 1, wherein the sleep state informed therapy comprises a cardiac therapy.

5. The method of claim 1, wherein the sleep state informed therapy comprises a preventative therapy.

6. The method of claim 1, wherein the condition associated with the sleep-wake status of the patient comprises patient activity.

7. The method of claim 1, wherein sensing the condition associated with the sleep-wake status includes detecting patient activity using an accelerometer.

8. The method of claim 1, wherein sensing the condition associated with the sleep-wake status includes detecting body posture.

9. The method of claim 1, wherein the condition associated with the sleep-wake status includes a patient activity signal, and wherein classifying includes determining sleep onset by comparing the patient activity signal to a sleep threshold.

10. The method of claim 9, wherein classifying also includes determining sleep offset by comparing the patient activity signal to the sleep threshold.

11. The method of claim 1, wherein classifying includes determining REM sleep onset by comparing the pectoral muscle tone to an REM sleep threshold.

12. The method of claim 11, wherein classifying also includes determining REM sleep offset by comparing the pectoral muscle tone to the REM sleep threshold.

13. The method of claim 1, further comprising:

detecting a cardiac signal;

wherein the sleep state informed therapy includes bradycardia pacing therapy responsive to the detected cardiac signal and adapted to switch to a lower pacing rate based on the sleep state classification.

14. The method of claim 1, further comprising:

detecting a cardiac signal;

wherein the sleep state informed therapy includes preventative arrhythmia therapy responsive to the detected cardiac signal and to the sleep state classification.

15. The method of claim 1, further comprising:

detecting a cardiac signal;

analyzing the cardiac signal on a beat-to-beat basis;

wherein the sleep state informed therapy is responsive to the beat-to-beat cardiac signal analysis.

16. The method of claim 1, further comprising:

detecting a tidal volume of the patient'"'"'s respiration; and

declaring a hypopnea event if the tidal volume falls below a hypopnea threshold.

17. The method of claim 16, further comprising:

declaring an apnea event if the tidal volume falls below an apnea threshold lower than the hypopnea threshold.

34. The device of claim 8, wherein the detector system further includes a third sensor configured to detect a cardiac signal, the device further comprising:

an analyzer configured to analyze the cardiac signal on a beat-to-beat basis;

wherein the therapy system is configured to provide therapy based on both the sleep state classification and the beat-to-beat cardiac signal analysis.

18. An implantable cardiac rhythm management device configured to be implanted in a pectoral region of a patient, the device comprising:

a detector system comprising a first and second sensor,

the first sensor disposed on the implantable cardiac rhythm management device, the first sensor configured to sense muscle tone in the pectoral region of the patient and to detect REM sleep status based on the pectoral muscle tone, and

the second sensor configured to detect sleep-wake status of the patient;

a classification system coupled to the detector system and configured to classify sleep state based on the REM sleep status and the sleep-wake status; and

a therapy system coupled to the classification system and configured to provide cardiac therapy to the patient based on the sleep state classification.

19. The device of claim 18, wherein the first sensor is an electromyogram sensor.

20. The device of claim 18, wherein the cardiac rhythm management device comprises:

a housing adapted for implantation in the pectoral region of the patient;

wherein the first sensor is mechanically coupled to the housing.

21. The device of claim 20, wherein the classification system is disposed within the housing.

22. The device of claim 20, wherein the first sensor is positioned on the housing.

23. The device of claim 20, further comprising a header mounted on the housing, and the first sensor is positioned on the header.

24. The device of claim 18,

wherein the cardiac rhythm management device comprises a housing adapted for implantation in the pectoral region of the patient;

and

a lead coupled to the housing;

wherein the first sensor is disposed on the lead.

25. The device of claim 18, wherein the second sensor includes an accelerometer.

26. The device of claim 18, wherein the second sensor includes a body posture detector.

27. The device of claim 18, wherein the second sensor is configured to detect a patient activity signal, and wherein the classification system is configured to determine sleep onset by comparing the patient activity signal to a sleep threshold.

28. The device of claim 27, wherein the classification system is also configured to determine sleep offset by comparing the patient activity signal to the sleep threshold.

29. The device of claim 18, wherein the classification system is configured to determine REM sleep onset by comparing the pectoral muscle tone to an REM sleep threshold.

30. The device of claim 29, wherein the classification system is also configured to determine REM sleep offset by comparing the pectoral muscle tone to the REM sleep threshold.

31. The device of claim 18, wherein the detector system further includes a third sensor configured to detect a cardiac signal, and wherein the therapy system is configured to provide bradycardia pacing therapy responsive to the detected cardiac signal and to the sleep state classification.

32. The device of claim 31, wherein the bradycardia pacing therapy is adapted to switch to a lower pacing rate based on the sleep state classification.

33. The device of claim 18, wherein the detector system further includes a third sensor configured to detect a cardiac signal, and wherein the therapy system is configured to provide preventative arrhythmia therapy responsive to the detected cardiac signal and to the sleep state classification.

35. The device of claim 18, wherein the detector system further includes a third detector configured to detect a tidal volume of the patient'"'"'s respiration, and wherein the therapy system is configured to declare a hypopnea event if the tidal volume falls below a hypopnea threshold.

36. The device of claim 35, wherein the therapy system is also configured to declare an apnea event if the tidal volume falls below an apnea threshold lower than the hypopnea threshold.