PROBLEM TO BE SOLVED: To acquire a highly-accurate optical coefficient by considering sensitivity of a phase to an optical coefficient of each modulation frequency.SOLUTION: A subject information acquisition device to be used includes: light detection means that detects multiple intensity-modulated light rays which mutually differ in intensity-modulated frequency showing a change in intensity of light transmitted through a subject, and then generates a light detection signal acoustic wave detection means that generates a photoacoustic signal derived from the subject and processing means that acquires a detected amplitude attenuation rate and a detected phase from the light detection signal, with respect to each intensity-modulated frequency, generates an estimated amplitude attenuation rate and an estimated phase, with respect to the intensity-modulated light, on the basis of both a prescribed estimated absorption coefficient and a prescribed estimated scattering coefficient concerning the subject, generates a weighted phase residual error which is weighted according to a phase residual error showing a residual error between the detected phase and the estimated phase, generates an amplitude attenuation rate residual error showing a residual error between the detected amplitude attenuation rate and the estimated amplitude attenuation rate, and then generates an absorption coefficient and a scattering coefficient, with respect to the subject, from a value obtained from the weighted phase residual error and the amplitude attenuation rate residual error.COPYRIGHT: (C)2015,JPO&INPIT【課題】変調周波数ごとの光学係数に対する位相の感度を考慮することで、高精度な光学係数を取得する。【解決手段】被検体を伝搬した光強度の変化を表す強度変調周波数が互いに異なる複数の強度変調光を検出して光検出信号を生成する光検出手段と、被検体に由来する光音響信号を生成する音響波検出手段と、光検出信号から、強度変調周波数ごとに、検出振幅減衰率および検出位相を取得し、被検体に関する所定の推定吸収係数および所定の推定散乱係数に基づいて強度変調光の推定振幅減衰率と推定位相を生成し、検出位相と推定位相との残差を示す位相残差に応じた加重をかけた加重位相残差を生成し、検出振幅減衰率と推定振幅減衰率との残差を示す振幅減衰率残差を生成し、加重位相残差および振幅減衰率残差から求められる値から被検体の吸収係数および散乱係数を生成する処理手段を有する被検体情報取得装置を用いる。【選択図】図1
