中文摘要：

本文研究了生物组织的改进的δ-P。近似漫反射光学模型，推导了含有等效光源一阶矩的双点源近似空间分辨漫反射解Rδ-p1（p）．研究表明，考虑等效光源一阶矩的光学模型，较好地描述了具有强的前向散射特性和较大吸收系数的生物组织散射特性；与漫射近似下的漫反射率RSDA（P）相比，新的光学模型能较好地描述光源附近的漫辐射强度分布，并且由于解析表达式中含有散射相函数的二阶参量y，这对于在近光源区域由空间分辨漫反射测量数据来反演生物组织的光学参量具有重要的意义．

英文摘要：

A modified delta-P1 approximation is studied in this paper. An analytic solution Rδ-p, （p） of this model for reflectance in double source approximation is developed by taking the source series expansion terms to the first order. It is shown that when the source in extended to first order, a better description for high absorption and high scattering media will be developed. The new model can give satisfactory results in describing irradiance distribution close to source compared with the RSDA （p） of diffusion approximation. Moreover, Rδ-p, （p） provides the prediction of the second-order parameter 7, which is significant for developing the inversion algorithm to recover optical parameters from spatially-resolved diffuse reflectance by using smaller source-detector separations.