PROBLEM TO BE SOLVED: To implement acquisition of a posture during sleeping by using a non-contact and small-sized device.SOLUTION: A biological information acquisition device irradiates a subject during sleeping with a micro wave and takes in data obtained by detecting the micro wave reflected by the subject (50)； divides the data on the basis of timing when the body of the subject moves (54)； extracts a breathing component from the individual divided data (56 to 62)； and sets a posture determination threshold (66). The biological information acquisition device determines apnea when extracting no breathing component (72), determines that the subject is on the back when average amplitude Pt of the breathing component is larger than a posture determination threshold T(76), determines that the subject is on the side when the average amplitude Pt is smaller than a posture determination threshold T(T<；T) (82), and determines that the subject is on the stomach when the average amplitude Pt is equal to or larger than the posture determination threshold T(80).【課題】睡眠時の体位を取得することを、非接触かつ小型の機器で実現する。【解決手段】睡眠中の被検者にマイクロ波を照射し被検者で反射されたマイクロ波の検出データを取り込み(50)、被検者の体動が有ったタイミングを基準としてデータを分割し(54)、分割した個々のデータから呼吸成分を抽出し(56～62)、体位判定閾値を設定する(66)。そして、呼吸成分が無ければ無呼吸と判定し(72)、呼吸成分の平均振幅Ｐtが体位判定閾値ＴＦＵより大きければ体位を仰向けと判定し(76)、平均振幅Ｐtが体位判定閾値ＴＦＳ(ＴＦＳ＜ＴＦＵ)より小さければ体位を横向きと判定し(82)、平均振幅Ｐtが体位判定閾値ＴＦＳ以上であれば体位をうつ伏せと判定する(80)。【選択図】図５
