Time Integrated Spectroscopy of Turbid Media Based on the Microscopic Beer–Lambert Law: Application to Small-Size Phantoms Having Different Boundary Conditions

Abstract

Continued work on time-integrated spectroscopy (TIS) is presented to quantify absorber concentrations in turbid media. We investigated the applicability of the TIS method to small-size media that have different boundary conditions by measuring two 20×20×50 mm 3 cuboid liquid tissue-like phantoms at various absorption levels (absorption coefficients of the phantom from 2.5×10 -3 to 4.4×10 -2 mm -1 at 782 nm and from 3.1×10 -3 to 2.7×10 mm -1 at 831 nm). The scattering and absorbing solution was filled into ordinary and black-anodized aluminum containers to provide different boundary conditions. By means of a single equation, the absorber concentrations have been recovered within errors of a few percent in both cases. This demonstrates that the TIS method can quantify absorbers in small-size media having different boundary conditions. © 1999 Society of Photo-Optical Instrumentation Engineers.