System and method for evaluating task effectiveness based on sleep pattern

• US 6,579,233 B2
• Filed: 07/06/2001
• Issued: 06/17/2003
• Est. Priority Date: 07/06/2001
• Status: Active Grant

• Current Assignee: United States Army (U.S. Department Of Defense)
• Original Assignee: Science Applications International Corporation
• Inventors: Hursh, Steven Rawlings
• Primary Examiner(s): Hindenburg, Max F.
• Assistant Examiner(s): ASTORINO, MICHAEL C
• Application Number:
  US09/899,540
• Publication Number:
  US 20030013943A1
• Time in Patent Office: 711 Days
• Field of Search: 600/300-301, 600/509, 600/515, 600/521, 600/544-545, 600/595, 128/898, 128/920-925, 607/88, 607/2.4, 607/25, 607/27, 607/19, 514/288
• US Class Current: 600/300
• CPC Class Codes: A61B 5/16 Devices for psychotechnics using teaching or educational appliances G09B1/00 - G09B7/00; Testing reaction times ; Devices for evaluating the psychological state
• 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: G16H 20/30 relating to physical therapies or activities, e.g. physiotherapy, acupressure or exercising
• CPC Class Codes: G16H 50/50 for simulation or modelling of medical disorders
• CPC Class Codes: G16H 50/70 for mining of medical data, e.g. analysing previous cases of other patients
• CPC Class Codes: Y10S 128/92 Computer assisted medical diagnostics

Abstract

A method for evaluating the effectiveness of a person to perform a task based on his/her previous or predicted sleep activity is provided. The method can be used to predict changes in task effectiveness at any time of day, based upon numerous patterns of sleep and activity, either experienced or planned for the future. The method take into account progressive increases in sleep deprivation, the effects of the time of day on performance, and changes in the time when a person sleeps and works. The method also accounts for the quality of a sleep interval and a person'"'"'s sleep inertia, the temporary slowing of performance immediately after awakening. The method is homeostatic. Gradual decreases in sleep debt decrease sleep intensity. Progressive increases in sleep debt produced by extended periods of less than optimal levels of sleep lead to increased sleep intensity. As a result the method can predict the normal decline in sleep intensity during the sleep period and the normal equilibrium of performance under less than optimal schedules of sleep.

Claims

1. A method of evaluating the effectiveness of a person to perform a task based on previous or predicted sleep pattern comprising the steps of:

modeling circadian oscillators for the person;

calculating the amount of effective sleep in a sleep reservoir for the person based on the person'"'"'s sleep and activity pattern; and

calculating an effectiveness of the person to perform said task based on said oscillators and said sleep reservoir.

2. A method as recited in claim 1, comprising the further step of calculating a sleep debt.

3. A method as recited in claim 2, further comprising the step of calculating sleep intensity based on said sleep debt.

4. A method as recited in claim 3, wherein said step of modeling circadian oscillators further comprises determining sleep propensity and performance rhythm.

5. A method as recited in claim 4, wherein said step of calculating a sleep intensity is based on sleep propensity and said sleep debt.

6. A method as recited in claim 4, wherein said step of modeling circadian oscillators is done according to the equation:

7. A method as recited in claim 6, wherein said step of modeling circadian oscillators further comprises determining sleep propensity and performance rhythm, said sleep propensity is determined by the following equation:

8. A method as recited in claim 7, wherein sleep intensity is determined according to the equation:

9. A method as recited in claim 8, comprising the further steps of determining if the person'"'"'s sleep experienced any fragmentation, and calculating sleep accumulation based on said sleep intensity and said fragmentation, according to the equation:

10. A method as recited in claim 6, wherein said step of modeling circadian oscillators further comprises determining sleep propensity and performance rhythm, said performance rhythm is determined by the following equation:

11. A method as recited in claim 10, comprising the further steps of determining if the person'"'"'s sleep experienced any fragmentation and determining sleep inertia for the person, wherein said step of determining sleep inertia is performed according to the equation:

12. A method as recited in claim 2, wherein said step of calculating said sleep debt is determined by the following equation:

13. A method as recited in claim 2, wherein said step of determining the person'"'"'s sleep debt is based on said amount of effective sleep in the sleep reservoir.

14. A method as recited in claim 1, comprising the further step of determining if the person'"'"'s sleep experienced any fragmentation.

15. A method as recited in claim 14, comprising the further steps of calculating a sleep debt, calculating sleep intensity based on said sleep debt, and calculating sleep accumulation based on said sleep intensity and said fragmentation.

16. A method as recited in claim 15, wherein said step of calculating the amount of effective sleep in the sleep reservoir is performed based on said sleep accumulation and depletion due to performance use by the person.

17. A method as recited in claim 16, wherein said performance use is calculated according to the equation:

18. A method as recited in claim 14, wherein said step of determining if the person'"'"'s sleep experienced any fragmentation is based on frequency of awakenings from sleep.

19. A method as recited in claim 1, comprising the further step of determining sleep inertia for the person.

20. A method as recited in claim 19, wherein said step of determining sleep inertia is based on sleep intensity at a time of awakening.

21. A method as recited in claim 19, wherein said effectiveness of the person to perform said task is calculated based upon said circadian oscillators, said amount of effective sleep in said sleep reservoir, and said sleep inertia.

22. A method as recited in claim 19, wherein said step of determining sleep inertia is performed according to the equation:

23. A method as recited in claim 1, comprising the further step of adjusting phases of said circadian oscillators to reflect new time zones or shift schedules.

24. A method as recited in claim 1, wherein said circadian oscillators are determined by determining a new average awake hour at an end of each period of wakefulness, said new average awake hour being an average of that period of wakefulness averaged with an average awake hour of two prior periods of wakefulness.

25. A method of evaluating the effectiveness of a person to perform a task based on sleep patterns comprising the steps of:

modeling circadian oscillators for the person;

determining the person'"'"'s sleep debt;

calculating the amount of effective sleep in a sleep reservoir for the person;

determining if the person'"'"'s sleep experienced any fragmentation; and

calculating the effectiveness of the person to perform said task.

26. A method as recited in claim 25, comprising the further step of calculating a sleep intensity to determine a rate of sleep accumulation.

27. A method as recited in claim 26, wherein said step of calculating a sleep intensity is based on sleep propensity and said sleep debt.

28. A method as recited in claim 25, comprising the further step of determining sleep inertia for the person, and wherein said effectiveness of the person to perform said task is calculated based upon said circadian oscillators, said amount of effective sleep in said sleep reservoir, and said sleep inertia.

29. A method as recited in claim 25, wherein said step of modeling circadian oscillators further comprises determining sleep propensity and performance rhythm.

30. A method of evaluating the effectiveness of a person to perform a task based on his/her previous or predicted sleep pattern comprising the steps of:

modeling circadian oscillators for a person including the steps determining sleep propensity and performance rhythm;

calculating a sleep intensity for the person based on said sleep propensity and sleep debt;

determining if the person'"'"'s sleep experienced any fragmentation;

calculating the amount of effective sleep in a sleep reservoir for the person;

determining the person'"'"'s sleep debt based on said amount of effective sleep in a sleep reservoir resulting from sleep accumulation;

calculating sleep accumulation based on said sleep intensity and said fragmentation;

determining sleep inertia for the person; and

calculating the effectiveness of the person to perform said task based upon said circadian oscillators, said amount of effective sleep in said sleep reservoir, and said sleep inertia.

31. A system of evaluating the effectiveness of a person to perform a task based on sleep pattern comprising:

at least one input device for entering sleep/wake data;

a microprocessor that models circadian oscillators, calculates an amount of effective sleep in a sleep reservoir based on a sleep and activity pattern, and calculates an effectiveness to perform a task based on said oscillators and said sleep reservoir, based on said sleep/wake data; and

a display to show said effectiveness results.

32. A system as recited in claim 31, wherein said at least one input device provides data for an individual person.

33. A computer readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern comprising the steps of:

modeling circadian oscillators for a person;

calculating the amount of effective sleep in a sleep reservoir for the person based on their sleep and activity pattern; and

calculating an effectiveness of the person to perform said task based on said oscillators and said sleep reservoir.

34. A computer readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern, as recited in claim 33, comprising the further step of calculating a sleep debt.

35. A computer readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern, as recited in claim 34, further comprising the step of calculating sleep intensity based on said sleep debt.

36. A computer readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern, as recited in claim 34, wherein said step of determining the person'"'"'s sleep debt is based on said amount of effective sleep in a sleep reservoir.

37. A computer readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern, as recited in claim 33, comprising the further step of determining if the person'"'"'s sleep experienced any fragmentation.

38. A computer readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern, as recited in claim 37, comprising the further steps of calculating a sleep debt, calculating sleep intensity based on said sleep debt, and calculating sleep accumulation based on said sleep intensity and said fragmentation.

39. A computer readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern, as recited in claim 38, wherein said step of calculating the amount of effective sleep in a sleep reservoir is performed based on said sleep accumulation and depletion due to performance use by said person.

40. A computer readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern, as recited in claim 35, comprising the further step of determining sleep inertia for the person.

41. A computer readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern, as recited in claim 40, wherein said step of determining sleep inertia is based on the sleep intensity at a time of awakening.

42. A computer readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern, as recited in claim 33, wherein said step of modeling circadian oscillators further comprises determining sleep propensity and performance rhythm.

43. A computer-readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern comprising the steps of:

modeling circadian oscillators for a person including the steps of modeling circadian oscillators further comprises determining sleep propensity and performance rhythm;

calculating a sleep intensity for the person based on said sleep propensity and said sleep debt;

determining if the person'"'"'s sleep experienced any fragmentation;

calculating the amount of effective sleep in a sleep reservoir for the person;

determining the person'"'"'s sleep debt based on said amount of effective sleep in a sleep reservoir resulting from sleep accumulation;

calculating sleep accumulation based on said sleep intensity and said fragmentation;

determining sleep inertia for the person; and

calculating the effectiveness of the person to perform said task based upon said circadian oscillators, said amount of effective sleep in said sleep reservoir, and said sleep inertia.

44. A computer-readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern, as recited in claim 43, wherein said method is homeostatic, so that gradual decreases in sleep debt decrease said sleep intensity, and progressive increases in said sleep debt produce an increase in said sleep intensity.

45. A computer-readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern comprising the steps of:

modeling circadian oscillators for the person;

determining the person'"'"'s sleep debt;

calculating the amount of effective sleep in a sleep reservoir for the person;

determining if the person'"'"'s sleep experienced any fragmentation; and

calculating the effectiveness of the person to perform said task.

46. A computer-readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern, as recited in claim 45, comprising the further step of calculating a sleep intensity.

47. A computer-readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern, as recited in claim 45, comprising the further step of determining sleep inertia for the person.

48. A computer-readable medium having computer-executable instructions for evaluating the effectiveness of a person to perform a task based on sleep pattern, as recited in claim 45, wherein said step of modeling circadian oscelators further comprises determining sleep propensity and performance rhythm.