生物组织光学特性参量的图像测量研究

Photography measurement of optical parameters of biological tissues

为了测量生物组织的光学特性参量,采用CCD漫反射法和透射法,通过分析CCD摄取的待测样品表面的漫反射光分布图像,利用漫射近似理论,实现了漫反射法对生物组织模拟液(intralipid-20%稀释液)、牛肌肉、猪肌肉和鸡胸肉光学特性参量的测量,获得了样品的吸收系数和有效散射系数;测量了不同浓度生物组织模拟液的透射光强度,根据Beer-Lambert定律,实现了透射法对光学特性参量的测量,获得了样品的散射系数,进而得到了有效散射系数;并将漫反射法和透射法对同种样品光学特性参量的测量结果以及他人的测量结果进行了比较。结果表明,漫反射法和透射法的测量结果有很好的吻合性,测量生物组织光学特性参量采用的CCD测量装置和处理方法具有较高的精度。

To measure optical parameters of biological tissues, CCD diffusing reflection and transmission measurements were introduced. Analyzing the CCD photograph of diffusing reflection distribution on the specimen surface, the reduced scattering coefficient and absorption coefficient of biological tissue simulating liquid （ intralipid-20% diluents ） , beef, pork and chicken were derived from nonlinear regression of the diffusion equation with spatially resolved steady-state diffuse reflectance which was measured by the CCD diffusing reflection measuring equipment. The scattering coefficient was derived from linear regression of the Beer-Lambert equation with transmission light intensity of biological tissue simulating liquid of different titer which was measured by the CCD transmission measuring equipment, and then the reduced scattering coefficient was also deduced. Optical parameters of the same specimen measured by CCD diffusing reflection and transmission measurements were compared with those measured by others, and they were coherent. It is shown that the experimental CCD equipment and the treatment methods used to measure optical parameters have a high accuracy.