To calculate a heartbeat interval from biological information including a ballistocardiogram or a biovibration signal.SOLUTION: A biological information acquisition device comprises: biological information acquiring means for acquiring biological information including at least a ballistocardiogram or a biovibration signal of an animal； and heartbeat interval calculating means for calculating variation in heartbeat interval from the biological information. The heartbeat interval calculating means subjects a signal derived from a ballistocardiogram waveform or a biovibration signal to a process of filtering with a frequency higher than a heartbeat frequency as a minimum frequency and taking an absolute value with respect to a signal having passed through the filter.SELECTED DRAWING: None【課題】 心弾動図又は生体振動信号を含む生体情報から心拍間隔を算出する。【解決手段】 少なくとも動物の心弾動図又は生体振動信号を含む生体情報を取得する生体情報取得手段と、生体情報から心拍間隔の変動を算出する心拍間隔算出手段を有し、心拍間隔算出手段は、心弾動図波形又は生体振動信号に由来する信号に対し、心拍の周波数よりも高い周波数を下限周波数とするフィルタを通過させ、フィルタを通過させた後の信号について絶対値をとる処理を行う。【選択図】 なし
