Patent ID: 6230035
Filing Date: 2001-05-08
Classification: A61B

Abstract:
An apparatus for measuring a ratio of concentration of light absorbing materials in a living tissue, comprising:irradiating means for irradiating a living tissue with scattered light of different wavelengths;light receiving means for receiving either light transmitted through or light reflected from said living issue and for converting said light into corresponding electric signals; andconcentration-ratio processing means for calculating ratios of concentrations of light absorbing materials in accordance with said corresponding electric signals on the assumption that non-absorptive attenuation is equal independently of the wavelengths of light,wherein said concentration-ratio processing means calculates changes of optical densities of the living tissue by use of pulsations of intensities of transmitted light, and calculates a ratio of concentrations of light absorbing materials by use of said calculated changes of the optical densities.