A biological information measuring apparatus (1) includes a phase frequency comparator (21) for outputting a deviation signal corresponding to a phase difference between a biological signal and an oscillation signal, a cutoff frequency and a phase margin, and a deviation signal A variable loop filter for selectively blocking a signal in a predetermined frequency band included in the output signal from the variable loop filter and a voltage controlled oscillator for generating and outputting an oscillation signal in accordance with the deviation signal passed through the variable loop filter, An SN analyzer (31) for estimating the SN ratio of the biological signal, and a PF analyzer (32) for analyzing a phase difference / frequency difference between the biological signal and the oscillation signal from the output of the phase frequency comparator (21) And a parameter control unit (40) for changing the constant of the variable loop filter (22) based on the SN ratio, the phase difference / frequency difference, and the biological signal analyzing unit (30).生体情報計測装置(1)は、生体信号と発振信号との位相差に応じた偏差信号を出力する位相周波数比較器(21)と、カットオフ周波数及び位相余裕を可変することができ、偏差信号に含まれる所定の周波数帯域の信号を選択的に遮断する可変ループフィルタ(22)と、可変ループフィルタ(22)を通過した偏差信号に応じて発振信号を生成・出力する電圧制御発振器(23)と、生体信号のSN比を推定するSN解析部(31)、及び位相周波数比較器(21)の出力から生体信号と発振信号との位相差・周波数差を解析するPF解析部(32)を有する生体信号解析部(30)と、SN比、位相差・周波数差に基づいて、可変ループフィルタ(22)の定数を変更するパラメータ制御部(40)とを備える。
