JP2959376B

PURPOSE:To reduce a noise due to vibration and electromagnetic induction and to surely judge presence/absence without giving a sense of incongruity to a person. CONSTITUTION:This device is equipped with a body movement detection means 6 which detects the body movement of the person, a data collection means 9 which converts a signal to time series data, a dispersion value calculation means 10 which calculates the dispersion value of the time series data, and a decision means 11 which decides the presence/absence of the person according to the dispersion value. In this way, it is possible to clearly discriminate the presence of the person even keeping a rest state from the absence or an object. Especially, judgment can be rendered with superior reproducibility since an output signal from the body movement detecting means 6 is converted to digitized time series data.