PROBLEM TO BE SOLVED: To allow a sleep stage of a subject of measurement to be accurately determined without giving a burden on the subject of measurement.SOLUTION: Body motion and a heart rate of a subject of measurement are detected. When a standard deviation value of detection data every first period of the body motion of the subject of measurement obtained in detection is equal to a prescribed threshold or larger, awakening or non-REM sleep at a stage 1 is determined and, when it is not equal to the prescribed threshold or larger, REM sleep or non-REM sleep equal to a stage 2 or lower is determined. When the REM sleep or the non-REM sleep equal to the stage 2 or lower is determined in determination processing, processing to distinguish the REM sleep from the non-REM sleep equal to the stage 2 or lower is performed on the basis of an increase rate of a median value of the heart rate every second period of the subject of measurement and a frequency analysis result of the body motion of the subject of measurement every third period.SELECTED DRAWING: Figure 10COPYRIGHT: (C)2018,JPO&INPIT【課題】被測定者に負担をかけずに、被測定者の睡眠段階を精度良く判定できるようにする。【解決手段】被測定者の被測定者の体動及び心拍を検出する。その検出で得た被測定者の体動の第１の期間毎の検出データの標準偏差値が、所定の閾値以上であるとき、覚醒又はステージ１のノンレム睡眠と判定し、所定の閾値以上でないとき、レム睡眠又はステージ２以下のノンレム睡眠と判定する。さらに、その判定処理で、レム睡眠又はステージ２以下のノンレム睡眠と判定した場合に、被測定者の第２の期間毎の心拍の中央値の増加率と、被測定者の体動の第３の期間毎の周波数解析結果に基づいて、レム睡眠と、ステージ２以下のノンレム睡眠とを区別する処理を行う。【選択図】図１０
