Sleep state estimation device and program product for providing a computer with a sleep state estimation function

Abstract

An object of the present invention is to provide a sleep state estimation device capable of estimating a sleep state (deep sleep, light sleep) in real time with relative simplicity. Voltage variations resulting from human respiratory movement are measured for each given period to calculate from the measurement results positive voltage peak values and time intervals between adjacent peaks. The obtained peak values and peak intervals are used to calculate a mean peak interval value A, a coefficient of variation B based on dispersion of the peak intervals, and a coefficient of variation C based on the peak values. The sleep state in this period is estimated from the calculation results. More specifically, referring to FIG., the sleep state is estimated as a 'wakeful state' or a 'hypnagogic state' by checking whether the mean value A is larger or smaller than a threshold a and whether the coefficient of variation C is larger or smaller than a threshold c (S) whereas the sleep state is estimated as the “hypnagogic state”, “light sleep” or “deep sleep” by checking whether the coefficient of variation B is larger or smaller than a threshold b and whether the coefficient of variation C is larger or smaller than the threshold c (S, S, S, S).