System for discriminating sleep state
First Claim
1. A system for discriminating a sleep state of and selectively waking a subject, the system comprising means for setting a measuring time, means for measuring, as a biological signal of the subject, at least one biological signal per unit time selected from the group consisting of pulse rate and respiration rate, a variation index computing means for providing variation indexes C(t) representing variation of the biological signal H(t) in the form of a linear combination of first variation amount I(t) denoting a tendency of increment in time series of said biological signal H(t) from a starting time of the measuring to a time when the biological signal is obtained with second variation amount D(t) denoting a standard variation of the biological signal H(t) during said measuring time, and a sleep index operating means for providing sleep indexes allowing a NREM sleep state and all other sleep states to be discriminated from one another on the basis of said variation indexes C(t) continuously exceeding a predetermined threshold C(th).
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Abstract
A system for discriminating sleep state of human body provides variation indexes representing variation of the biological signal on the basis of first variation amount denoting a tendency of increment in time series of measured biological signal from the starting time of the measurement and second variation amount denoting the temporal variation of the biological signal, and discriminates different sleep state on the basis of distribution density of the variation indexes exceeding a predetermined threshold, whereby NREM and REM sleep periods in particular can be reliably discriminated, to be sufficiently contributive to a transmission of sleep information that ensures a comfortable awakening.
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Citations
7 Claims
- 1. A system for discriminating a sleep state of and selectively waking a subject, the system comprising means for setting a measuring time, means for measuring, as a biological signal of the subject, at least one biological signal per unit time selected from the group consisting of pulse rate and respiration rate, a variation index computing means for providing variation indexes C(t) representing variation of the biological signal H(t) in the form of a linear combination of first variation amount I(t) denoting a tendency of increment in time series of said biological signal H(t) from a starting time of the measuring to a time when the biological signal is obtained with second variation amount D(t) denoting a standard variation of the biological signal H(t) during said measuring time, and a sleep index operating means for providing sleep indexes allowing a NREM sleep state and all other sleep states to be discriminated from one another on the basis of said variation indexes C(t) continuously exceeding a predetermined threshold C(th).
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7. A system for discriminating a sleep state of and selectively waking a subject, the system comprising means for setting a measuring time, means for measuring as a biological signal of the subject at least one biological signal per unit time selected from the group consisting of pulse rate and respiration rate, a variation index computing means for providing variation indexes C(t) representing variation of the biological signal H(t) in the form of a linear combination of first variation amount I(t) denoting a tendency of increment in time series of said biological signal H(t) from a starting time of the measuring to a time when the biological signal is obtained with second variation amount D(t) denoting a standard variation of the biological signal H(t) during said measuring time, said variation index computing means for performing a regression operation on said biological signal, and a sleep index operating means for providing sleep indexes allowing a NREM sleep state and all other sleep states to be discriminated from one another on the basis of said variation indexes C(t) continuously exceeding a predetermined threshold C(th).
Specification