Human internal structure such as a frontal sinus and other parts is noninvasively measured and using this measured result, the accuracy of a bioinstrumentation is improved. In order to noninvasively measure a frontal sinus distribution, a bioinstrumentation device has: a light source for irradiating light to a subject; a light detector for detecting the light irradiated from the light source and having propagated through the inside of the subject; a control unit for controlling the light source and the light detector; an amplifier for amplifying a light detection signal; an analog-digital converter; an analysis unit for analyzing a digital signal; and a display unit for displaying the analyzed result. The bioinstrumentation device measures the optical characteristics of the subject, whereby the subject's internal structure including the frontal sinus is measured and displayed. The bioinstrumentation device also uses frontal sinus distribution information obtained by using a light transmissivity distribution measured at a plurality of light source-detector distances to adjust a light source power and a light detector sensitivity in optical brain function measurements, thereby providing means for correcting bioinstrumentation data of optical brain function measurements, fMRI, and other measurements. Further, in fMRI, a measurement in which artifacts are reduced is achieved by previously using the frontal sinus distribution.
BIOINSTRUMENTATION DEVICE