PROBLEM TO BE SOLVED: To provide in-bed state determination technology for properly determining an in-bed state.SOLUTION: A plurality of load meters are disposed such that the load meters distributively measure loads of every moment applied onto installation faces by a bed. A gravity center calculation part calculates the gravity center based on a plurality of measurement values measured by the plurality of load meters. A gravity center variation amount calculation part calculates a gravity center variation amount that is a variation amount of the gravity center within a prescribed time, and person presence/absence determination part determines whether a person is present or absent on the bed based on the gravity center variation amount.COPYRIGHT: (C)2012,JPO&INPIT【課題】的確に在床状態を判定することができる在床状態判定技術を提供する。【解決手段】ベッドが設置面に加える時々刻々の荷重を分散して計測するように複数の荷重計が配置されている。重心算出部はこの複数の荷重計により計測された複数の計測値に基づいて重心を算出する。また、重心変動量算出部が所定時間内における重心の変動量である重心変動量を算出し、人存否判定部が重心変動量に基づいてベッド上の人の存否を判定する。【選択図】図2
