Diffuse Reflectance Model Of Biological Tissue Based On P3 Approximation And Experimental Study

The studies of light propagation in biological tissue and tissue optical parameters are important and fundamental. The optical parameters which characterize the physiological properties of the tissue can be gained by analyzing the spatially resolved reflectance from the tissue. The optical parameters of tissue supplies the index parameters for clinical therapy and diagnose, has great instructional significance for the application in medical.P₃approximation theory describes the spatially resolved reflectance near the source. The effects of optical parameters including absorbing coefficientμa, efficient scattering coefficientμ's , the second-order parameterγand the third-order coefficientδon the diffused reflectance are studied, and the results show the influences are different in the region and extent.Based on the study of the P3 approximation theory, double-fibers equipment has been used in the experiment. The devices performance has been analyzed and debugged. We studied the effects on the distribution of reflectance by absorbing and scattering using the sample with different concentration made of Intralipid and Methylene blue, the results compared with P3 approximation show the same trend.Based on the experimental facility above, we designed and manufactured a linear array fibers probe, and tested its propagation characteristic were good. It can be used in the experiment to study the spatially resolved reflectance in the region of 0.3-4.2mm. The experimental system has been further studied, the multi-channel experimental system was designed, and the performance parameter of the components been studied.