Patent ID: 6335792
Filing Date: 2002-01-01
Classification: G01N

Abstract:
A method of measuring an internal property distribution of a scattering medium, said method comprising:a light injection step of successively injecting rays from at least one light injection position into a medium to be measured, which is a scattering medium; a light detection step of detecting rays having passed through the interior of said medium to be measured, at a plurality of light detection positions; a measurement value acquisition step of acquiring a measurement value of a predetermined parameter of said rays for each of combinations of said light injection position with said light detection positions, based on each ray detected; a reference value setting step of setting a reference value of an absorption coefficient of said medium to be measured; an estimate computation step of computing an estimate of said parameter for each of the combinations of said light injection position with said light detection positions, based on said reference value of the absorption coefficient, on the assumption that said medium to be measured has the homogeneous reference value of said absorption coefficient as a whole; a weight function operation step of obtaining a weight function in each voxel of said medium to be measured, the medium being divided into a plurality of voxels, based on the Microscopic Beer-Lambert Law, using said reference value of the absorption coefficient; an absorption coefficient deviation computation step of computing a deviation of the absorption coefficient from the reference value of the absorption coefficient in each voxel, based on the measurement value of said parameter, the estimate of said parameter, and said weight function; and an absorption coefficient absolute value computation step of computing an absolute value of the absorption coefficient in each voxel, based on the reference value of said absorption coefficient and the deviation of said absorption coefficient, to obtain a distribution of absolute values of absorption coefficients in said medium to be measured.