Applications of the 1-D Diffusion Approximation to the Optics of Tissues and Tissue Phantoms. (Reannouncement with New Availability Information).

摘要

The optical constants of biological tissues and their wavelength dependence have many applications, including the identification of tissue chromophores, determination of action spectra, calculation of photosensitization quantum yields, and modeling of laser-tissue interactions. The literature data are limited to relatively few wavelengths and generally are in poor agreement. The variability of tissue samples is a major problem. Except for optically thin layers, the microscopic optical constants are model dependent and must be extracted from measurements on multiply scattering samples. Radiative transfer theory provides a practical approach for most standard applications, in which the wave properties of light are ignored and light propagation is treated as equivalent to the flow of neutral particles. Accurate numerical solutions have led to reliable values of the macroscopic constants, usually the coefficients of diffuse reflection R sub d and transmission T sub d in terms of microscopic parameters: the linear scattering coefficient s, linear absorption coefficient k, and the angular dependence of the scattering cross section or phase function p.