Abstract
We propose a new method to determ ine the absorption coefficient (μ_a) of the lower layer in a two-layered medium using time-resolved spectroscopy (TRS). To estimate the variation of μ_a with the depth, the difference in the temporal profiles of light attenuation between a two-layered medium and a homogeneous one was divided into time segments, and a slope of each segment was calculated to get the time-segmented μ_a of the layered medium. Its validity was examined both by a Monte Carlo simulation and phantom experiments. The results suggest the possi bility that μ_a of hum an cerebral tissue can be selectively determined by TRS.
