Sleep detection using an adjustable threshold

• US 20040111041A1
• Filed: 12/04/2002
• Published: 06/10/2004
• Est. Priority Date: 12/04/2002
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Hatlestad, John D., Lee, Kent, Ni, Quan, Daum, Douglas R., Stahmann, Jeff E., Hajenga, Zoe
• Granted Patent: US 7,189,204 B2
• Time in Patent Office: Days
• US Class Current: 600/544
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• 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 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/085 Measuring impedance of respiratory organs or lung elasticity
• CPC Class Codes: A61B 5/1116 Determining posture transitions
• CPC Class Codes: A61B 5/4809 Sleep detection, i.e. determining whether a subject is asleep or not
• CPC Class Codes: A61B 5/4815 Sleep quality
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/7271 Specific aspects of physiological measurement analysis A61B5/316, A61B5/349 and A61B5/374 take precedence
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61N 1/362 Heart stimulators heart defibrillators A61N1/39
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371
• CPC Class Codes: A61N 1/36542 controlled by body motion, e.g. acceleration
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

Devices and methods for sleep detection involve the use of an adjustable threshold for detecting sleep onset and termination. A method for detecting sleep includes adjusting a sleep threshold associated with a first sleep-related signal using a second sleep-related signal. The first sleep-related signal is compared to the adjusted threshold and sleep is detected based on the comparison. The sleep-related signals may be derived from implantable or external sensors. Additional sleep-related signals may be used to confirm the sleep condition. A sleep detector device implementing a sleep detection method may be a component of an implantable pulse generator such as a pacemaker or defibrillator.

Claims

1. A method of detecting sleep, comprising:

adjusting a sleep threshold associated with a first sleep-related signal using a second sleep-related signal;

comparing the first sleep-related signal to the adjusted threshold; and

detecting sleep based on the comparison, wherein at least one of adjusting, comparing or detecting steps is performed at least in part implantably.

2. The method of claim 1, wherein at least one of the first or the second sleep-related signals is a physiological signal.

3. The method of claim 1, further comprising establishing the sleep threshold associated with the first sleep-related signal.

4. The method of claim 3, wherein the sleep threshold is established based on clinical data.

5. The method of claim 3, wherein the sleep threshold is established using the first sleep-related signal.

6. The method of claim 1, wherein detecting sleep based on the comparison comprises:

detecting sleep onset if the first sleep-related signal falls below the adjusted threshold; and

detecting sleep termination if the first sleep-related signal rises above the adjusted threshold.

7. The method of claim 1, wherein the first sleep-related signal is associated with patient activity.

8. The method of claim 1, wherein the first sleep-related signal is an accelerometer signal.

9. The method of claim 1, wherein the first sleep-related signal is sensed using an implantable sensor.

10. The method of claim 1, wherein the first sleep-related signal is sensed using an external sensor.

11. The method of claim 1, wherein the second sleep-related signal is associated with patient respiration.

12. The method of claim 1, wherein the second sleep-related signal comprises transthoracic impedance.

13. The method of claim 1, wherein the second sleep-related comprises minute ventilation.

14. The method of claim 1, wherein the second sleep-related signal comprises tidal volume.

15. The method of claim 1, wherein the second sleep-related signal is associated with cardiac function.

16. The method of claim 1, wherein the second sleep-related signal comprises a QT interval signal.

17. The method of claim 1, wherein the second sleep-related signal is sensed using an implantable sensor.

18. The method of claim 1, wherein the second sleep-related signal is sensed using an external sensor.

19. The method of claim 1, wherein detecting sleep comprises detecting sleep using an implantable device.

20. The method of claim 19, wherein the implantable device is an implantable pulse generator.

21. The method of claim 1, wherein detecting sleep comprises detecting sleep using an external device.

22. The method of claim 1, wherein detecting sleep further comprises confirming sleep using a third sleep-related signal.

23. The method of claim 1, wherein detecting sleep further comprises:

comparing a third sleep-related signal to a predetermined value; and

confirming sleep based on the comparison.

24. The method of claim 23, wherein the third sleep-related signal comprises a posture detector signal.

25. The method of claim 23, wherein the third sleep-related signal comprises a body temperature signal.

26. The method of claim 23, wherein the third sleep-related signal comprises an EOG signal.

27. The method of claim 23, wherein the third sleep-related signal comprises an EEG signal.

28. The method of claim 23, wherein the third sleep-related signal comprises an EMG signal.

29. The method of claim 23, wherein the third sleep-related signal comprises a respiration signal.

30. The method of claim 23, wherein the third sleep-related signal comprises a cardiac signal.

70. The method of claim 3, wherein the sleep threshold is established using data associated with historical sleep times.

72. The method of claim 23, wherein the third sleep-related signal comprises a blood pressure signal.

31. A sleep detection device, comprising:

a first sensor configured to sense a first sleep-related signal;

a second sensor configured to sense a second sleep-related signal; and

a sleep detector coupled to the first and the second sensors and configured to adjust a sleep threshold associated with the first sleep-related signal using the second sleep-related signal, and to detect a sleep condition by comparing the first sleep-related signal with the adjusted threshold, wherein one of the first sensor, second sensor and sleep detector comprises an implantable component.

32. The device of claim 31, wherein the sleep threshold is established based on clinical data.

33. The device of claim 31, wherein the sleep detector is further configured to establish the sleep threshold using the first sleep-related signal.

34. The device of claim 31, wherein the sleep detector is configured to detect sleep onset if the first sleep-related signal falls below the adjusted threshold and detect sleep termination if the first sleep-related signal rises above the adjusted threshold.

35. The device of claim 31, wherein the first sleep-related signal is associated with patient activity.

36. The device of claim 31, wherein the first sleep-related signal comprises a cardiac signal.

37. The device of claim 31, wherein the first sleep-related signal comprises a respiration signal.

38. The device of claim 31, wherein the first sleep-related signal comprises an accelerometer signal.

39. The device of claim 31, wherein the first sleep-related signal is derived from an implantable sensor.

40. The device of claim 31, wherein the first sleep-related signal is derived from an external sensor.

41. The device of claim 31, wherein the second sleep-related signal comprises a cardiac signal.

42. The device of claim 31, wherein the second sleep-related signal comprises a respiration signal.

43. The device of claim 31, wherein the second sleep-related signal comprises a transthoracic impedance signal.

44. The device of claim 31, wherein the second sleep-related signal comprises a minute ventilation signal.

45. The device of claim 31, wherein the second sleep-related signal is derived from an implantable sensor.

46. The device of claim 31, wherein the second sleep-related signal is derived from an external sensor.

47. The device of claim 31, wherein the sleep detector comprises an implantable device.

48. The device of claim 31, wherein the sleep detector comprises an external device.

49. The device of claim 31, wherein the sleep detector is configured as a component of a pulse generator.

50. The device of claim 31, wherein the sleep detector is configured as a component of a therapeutic device.

51. The device of claim 31, wherein the sleep detector is configured as a cardiac pacemaker.

52. The device of claim 31, wherein the sleep detector is configured as a component of a patient monitoring device.

53. The device of claim 31, further comprising:

a third sensor to sense a third sleep-related signal; and

wherein the sleep detector is further configured to compare the third sleep-related signal with a threshold and to confirm a sleep condition based on the comparison.

54. The device of claim 53, wherein the third sleep-related signal comprises a cardiac signal.

55. The device of claim 53, wherein the third sleep-related signal comprises a respiration signal.

56. The device of claim 53, wherein the third sleep-related signal comprises a body temperature signal.

71. The device of claim 31, wherein the sleep threshold is established using data associated with historical sleep times.

73. The device of claim 53, wherein the third sleep-related signal comprises a blood pressure signal.

57. A system for detecting sleep, comprising:

means for adjusting a sleep threshold associated with a first sleep-related signal using a second sleep-related signal;

means for comparing the first sleep-related signal to the adjusted threshold; and

means for detecting sleep based on the comparison,

wherein one of the means for adjusting, comparing or detecting comprises an implantable component.

58. The system of claim 57, further comprising means for establishing the sleep threshold associated with the first sleep-related signal.

59. The system of claim 57, further comprising:

means for sensing a third sleep-related signal;

means for comparing the third sleep-related signal to a predetermined value; and

means for confirming sleep based on the comparison.

60. A method of detecting sleep, comprising:

sensing a plurality of sleep-related signals;

defining a relationship between at least two of the sleep-related signals, the relationship associated with sleep detection; and

detecting sleep using the sleep-related signal relationship, wherein at least one of sensing, defining, and detecting is performed at least in part implantably.

61. The method of claim 60, wherein defining the relationship comprises defining the relationship between a patient activity signal and a respiratory signal.

62. The method of claim 60, wherein defining the relationship comprises defining the relationship between a cardiac signal and a respiratory signal.

63. The method of claim 60, wherein defining the relationship comprises establishing a sleep criterion.

64. The method of claim 63, wherein establishing the sleep criterion comprises establishing a sleep threshold associated with one of the sleep-related signals.

65. The method of claim 63, wherein establishing the sleep criterion further comprises modifying the sleep criterion.

66. The method of claim 63, wherein establishing the sleep criterion further comprises adjusting the sensitivity of the sleep criterion.

67. The method of claim 60, wherein at least one of the sleep-related signals is a physiological signal.

68. The method of claim 60, wherein at least one of the sleep-related signals is a non-physiological signal.

69. The method of claim 60, wherein detecting sleep comprises comparing a sleep criterion to a state of at least one of the sleep-related signals.