To simultaneously measure the attenuation information in a living body of a multiple wavelength light by detecting the light transmitted and diffused by the living body, converting it into an electric signal, determining the light attenuating degree by the living body every wavelength on the basis of the measurement result of intensity every frequency component of the electric signal, and calculating the absorbing material concentration in the living body.
The light diffused and reflected in a blood vessel 10 and incident on an optical fiber 8' is detected by a light detector 11 on the end surface opposite to the end surface pressed onto a living body 9 and converted into a voltage signal. The voltage signal is inputted to a frequency analyzer 12, the intensity every frequency component of the voltage signal is measured, and the measurement result is transmitted to a computer 13. The attenuating degree of the living body 9 is determined every wavelength by the computer 13, the absorbing material concentration in the living body 9 is calculated, and digitally displayed on the display of the computer 13. Thus, the attenuating information in the living body 9 of a multiple wavelength light can be simultaneously measured.
MIYAHARA YUJI
KAN MASAO
