Method for providing a therapy to a patient involving modifying the therapy after detecting an onset of sleep in the patient, and implantable medical device embodying same

• US 6,731,984 B2
• Filed: 06/07/2001
• Issued: 05/04/2004
• Est. Priority Date: 06/07/2001
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Jensen, Donald N., Mongeon, Luc R., Cho, Yong Kyun
• Primary Examiner(s): Jastrzab, Jeffrey R.
• Assistant Examiner(s): Oropeza, Frances P.
• Application Number:
  US09/876,528
• Publication Number:
  US 20020193839A1
• Time in Patent Office: 1,062 Days
• Field of Search: 600/509, 600/513, 607/4-7, 607/9, 607/11, 607/17-20, 607/27
• US Class Current: 607/17
• CPC Class Codes: A61N 1/36521 the parameter being derived from measurement of an electrical impedance
• CPC Class Codes: A61N 1/36542 controlled by body motion, e.g. acceleration

Abstract

An implantable medical device system is described including an implantable medical device for implantation in a patient. One embodiment of the implantable medical device includes a therapy component for providing a therapy to the patient, a minute ventilation (MV) sensing circuit producing MV values indicative of a MV of the patient at time intervals, and computational circuitry. The computational circuitry receives a number of the MV values over a period of time, calculates a statistical parameter (e.g., a mean) of the MV values, and calculates a deviation of the MV values from the statistical parameter (e.g., a standard deviation of the MV values). The computational circuitry detects an onset of sleep in the patient when the deviation of the MV values from the statistical parameter is less than a predetermined MV threshold value, and signals the therapy component to modify the therapy when the onset of sleep is detected in the patient. A method is disclosed for providing therapy to a patient, including detecting an onset of sleep in the patient, and modifying the therapy following the detecting the onset of sleep in the patient.

Claims

1. An implantable medical device for implantation in a patient, comprising:

a therapy component configured to provide a therapy to the patient;

a minute ventilation sensing circuit configured to produce minute ventilation values indicative of a minute ventilation of the patient at time intervals; and

computational circuitry coupled to the therapy component and the minute ventilation sensing circuit and configured to receive a plurality of the minute ventilation values at predetermined time intervals over a period of time, to generate a first threshold and a second threshold corresponding to a physiologic transition of the patient between a first state and a second state, to generate a first distribution late of minute ventilation values of the plurality of minute ventilation values received during first time intervals of the predetermined time intervals including a first current time interval m and first preceding time intervals m-1 and a second distribution rate of minute ventilation values of the plurality of minute ventilation values received during second time intervals of the predetermined time intervals including a second time interval n and a second preceding time intervals n-1, to detect onset of the second state in response to the second distribution rate being less than the first threshold, an abrupt transition between the first state and the second state, and the second distribution rate being greater than or equal to the first distribution rate, and to signal the therapy component to modify the therapy when the onset of the second state is detected in the patient.

2. The implantable medical device of claim 1, wherein the first threshold corresponds to one halt of a median of the plurality of minute ventilation values over the period of time.

3. The implantable medical device of claim 1, wherein the second threshold corresponds to a mean of the plurality of minute ventilation values aver the period of time.

4. The implantable medical device of claim 1, wherein the first threshold is greater than the second threshold.

5. The implantable medical device of claim 1, wherein n is greater than m.

6. The implantable medical device of claim 5, wherein m is selected such that the first distribution rate is generated over approximately a 2-5 minute period of time and n is selected such that the second distribution rate is generated over approximately a 10-15 minute period of time.

7. The implantable medical device of claim 1, further comprising an activity sensor coupled to the computational circuitry and configured to generate activity values indicative of a level of activity of the patient, wherein the computational circuitry detects onset of the second state in response to the activity values.

8. The implantable medical device of claim 1, wherein the computational circuitry includes a timing/pacing control circuit to generate time of day information, and wherein the computational circuitry detects onset of the second stage in response to the time of day information corresponding to the second state.

9. The implantable medical device of claim 8, wherein the computational circuitry detects the onset of the second stage in response to an amount of time, corresponding to the second distribution rate being less than the first threshold, being less than a predetermined transition time threshold.

10. The implantable medical device of claim 1, wherein the computational circuitry detects the onset of the second stage in, response to the second distribution rate being less than the second threshold.

11. The implantable medical device of claim 1, wherein the first state corresponds to the patient being awake and the second state corresponds to the patient being asleep.

12. The implantable medical device of claim 1, wherein the modification of the therapy includes one of reducing a lower rate, monitoring sleep-related events, modifying electrical shocks for treating atrial fibrillation, and modifying administration of medications.

13. The implantable medical device of claim 1, wherein the means for detecting detects the onset of the second stage in response to the second distribution rate being less than the second threshold.

14. The implantable medical device of claim 1, wherein the modifying includes one of reducing a lower rate, monitoring sleep-related events, modifying electrical shocks for treating atrial fibrillation, and modifying administration of medications.

15. An implantable medical device for implantation in a patient, comprising:

a therapy component configured to provide a therapy to the patient;

a minute ventilation sensing circuit configured to produce minute ventilation values indicative of a minute ventilation of the patient at time intervals;

an activity sensor configured to generate activity values indicative of a level of activity of the patient;

a timing/pacing control circuit to generate time of day information; and

computational circuitry coupled to the therapy component and the minute ventilation sensing circuit and configured to receive a plurality of the minute ventilation values at predetermined time intervals over a period of time to generate a first threshold and a second threshold corresponding to a physiologic transition of the patient between a first state and a second state, to generate a first distribution rate of minute ventilation values of the plurality of minute ventilation values received during first time intervals of the predetermined time intervals Including a first current time interval m and first preceding time intervals m-1 and a second distribution rate of minute ventilation values of the plurality of minute ventilation values received during second time intervals of the predetermined time intervals including a second time Interval n and second preceding time intervals n-1, to detect onset of the second state In response to the second distribution rate being less than the first threshold, the activity levels, the time of day information corresponding to the second state, an abrupt transition between the first state and the second state, and the second distribution rate being greater than or equal to the first distribution rate, and to signal the therapy component to modify the therapy when the onset of the second state is detected in the patient.

16. The implantable medical device of claim 15, wherein the first threshold corresponds to one half of a median of the plurality of minute ventilation values over the period of time.

17. The implantable medical device of claim 15, wherein the second threshold corresponds to a mean of the plurality of minute ventilation values over the period of time.

18. The implantable medical device of claim 15, wherein the first threshold is greater than the second threshold.

19. The implantable medical device of claim 15, wherein n is greater than m.

20. The implantable medical device of claim 19, wherein m is selected such that the first distribution rate is generated over approximately a 2-5 minute period of time and n is selected such that the second distribution rate is generated over approximately a 10-15 minute period of time.

21. The implantable medical device of claim 15, wherein the computational circuitry detects the onset of the second stage in response to an amount of time, corresponding to the second distribution rate being less than the first threshold, being less than a predetermined transItion time threshold.

22. The implantable medical device of claim 15, wherein the computational circuitry detects the onset of the second stage in response to the second distribution rate being less than the second threshold.

23. The implantable medical device of claim 15, wherein the first state corresponds to the patient being awake and the second state corresponds to the patient being asleep.

24. The implantable medical device of claim 15, wherein the modification of the therapy includes one of reducing a lower rate, monitoring sleep-related events, modifying electrical shocks for treating atrial fibrillation, and modifying administration of medications.

25. A method of providing therapy to a patient having an implantable medical device, comprising:

sensing minute ventilation values indicative of a minute ventilation of the patient;

generating a first threshold and a second threshold corresponding to a physiologic transition of the patient between a first state and a second state in response to the minute ventilation values;

generating a first distribution rate of a plurality of the sensed minute ventilation values received during first time intervals of predetermined time intervals including a first current time interval m and first preceding time intervals m-1 and a second distribution rate of a plurality of the sensed minute ventilation values received during second time intervals of the predetermined time intervals including a second time interval n and second preceding time intervals n-1;

detecting onset of the second state In response to the second distribution rate being less than the first threshold, an abrupt transition between the first state and the second state, and the second distribution rate being greater than or equal to the first distribution rate; and

modifying the therapy in response to the detected onset of the second state.

26. The method of claim 25, wherein the first threshold corresponds to one half of a median of the plurality of minute ventilation values over the period of time.

27. The method of claim 25, wherein the second threshold corresponds to a mean of the plurality of minute ventilation values over the period of time.

28. The method of claim 25, wherein the first threshold is greater than the second threshold.

29. The method of claim 25, wherein n is greater than m.

30. The method of claim 29, wherein m is selected such that the first distribution rate is generated over approximately a 2-5 minute period of time and n is selected such that the second distribution rate is generated over approximately a 10-15 minute period of time.

31. The method of claim 25, further comprising generating activity values indicative of a level of activity of the patient, wherein the step of detecting includes detecting onset of the second state in response to the activity values.

32. The method of claim 25, further comprising generating time of day information, wherein the step of detecting includes detecting the onset of the second stage in response to the time of day information corresponding to the second state.

33. The method of claim 32, further comprising determining an amount of time corresponding to the second distribution rate being less than the first threshold, wherein the step of detecting includes detecting the onset of the second stage in response to the determined amount of time being less than a predetermined transition time threshold.

34. The method of claim 25, wherein the step of detecting includes detecting the onset of the second stage in response to the second distribution rate being less than the second threshold.

35. The method of claim 25, wherein the first state corresponds to the patient being awake and the second state corresponds to the patient being asleep.

36. The method of claim 25, wherein the step of modifying includes one of reducing a lower rate, monitoring sleep-related events, modifying electrical shocks for treating atrial fibrillation, and modifying administration of medications.

37. A method of providing therapy to a patient having an implantable medical device, comprising:

sensing minute ventilation values indicative of a minute ventilation of the patient;

generating activity values indicative of a level of activity of the patient;

generating time of day information;

generating a first threshold and a second threshold corresponding to a physiologic transition of the patient between a first state and a second state in response to the minute ventilation values;

generating a first distribution rate of a plurality of the sensed minute ventilation values received during first time intervals of predetermined time intervals including a first current time interval m and first preceding time intervals m-1;

generating a second distribution rate of minute ventilation values of the plurality of minute ventilation values received during second time intervals of the predetermined time intervals including a second time interval n and second preceding time intervals n-1;

detecting onset of the second state in response to the second distribution rate being less than the first threshold, the activity levels, the time of day information corresponding to the second state, an abrupt transition between the first state and the second state, and the second distribution rate being greater than or equal to the first distribution rate; and

modifying the therapy in response to the detected onset of the second state.

38. The method of claim 37, wherein the first threshold corresponds to one half of a median of the plurality of minute ventilation values over the period of time, the second threshold corresponds to a mean of the plurality of minute ventilation values over the period of time, and m is selected such that the first distribution rate is generated over approximately a 2-5 minute period of time and n is selected such that the second distribution rate is generated over approximately a 10-15 minute period of time.

39. The method of claim 38, further comprising determining an amount of time corresponding to the second distribution rate being less than the first threshold, wherein the step of detecting includes detecting the onset of the second stage in response to the determined amount of time being less than a predetermined transition time threshold.

40. The method of claim 39, wherein the step of detecting includes detecting the onset of the second stage in response to the second distribution rate being less than the second threshold.

41. The method of claim 40, wherein the first state corresponds to the patient being awake and the second state corresponds to the patient being asleep.

42. The method of claim 41, wherein the step of modifying includes one of reducing a lower rate, monitoring sleep-related events, modifying electrical shocks for treating atrial fibrillation, and modifying administration of medications.

44. The implantable medical device of claim 42, wherein the first threshold corresponds to one half of a median of the plurality of minute ventilation values over the period of time, the second threshold corresponds to a mean of the plurality of minute ventilation values over the period of time, the first threshold is greater than the second threshold, and m is selected such that the first distribution rate is generated over approximately a 2-5 minute period of time and n is selected such that the second distribution rate is generated over approximately a 10-15 minute period of time.

43. An implantable medical device for implantation in a patient, comprising:

means for sensing minute ventilation values indicative of a minute ventilation of the patient;

means for generating a first threshold and a second threshold corresponding to a physiologic transition of the patient between a first state and a second state in response to the minute ventilation values;

means for generating a first distribution rate of a plurality of the sensed minute ventilation values received during first time intervals of predetermined time intervals including a first current time interval m and first preceding time intervals m-1 and a second distribution rate of a plurality of the sensed minute ventilation values received during second time intervals of the predetermined time intervals including a second time interval n and second preceding time intervals n-1;

means for detecting onset of the second state in response to the second distribution rate being less than the first threshold, an abrupt transition between the first state and the second state, and the second distribution rate being greater than or equal to the first distribution rate; and

means for modifying the therapy in response to the detected onset of the second state.

45. The implantable medical device of claim 43, further comprising means for generating activity values indicative of a level of activity of the patient, wherein the means for detecting detects onset of the second state in response to the activity values.

46. The implantable medical device of claim 43, further comprising means for generating time of day information, and wherein the means for detecting detects onset of the second stage in response to the time of day information corresponding to the second state.

47. The implantable medical device of claim 46, further comprising means for determining an amount of time corresponding to the second distribution rate being less than the first threshold, wherein the means for detecting detects the onset of the second stage in response to the determined amount of time being less than a predetermined transition time threshold.

48. The implantable medical device of claim 43, wherein the first state corresponds to the patient being awake and the second state corresponds to the patient being asleep.