Refractive index of biotissue and its thermal response

摘要

The main significance about the refractive index of bio-tissue, its measurement methods and its thermal properties in particular are presented in this paper. Most of bio-tissue can be regarded as random dispersed medium which inhomogeous dimension is about the order of micrometers. In order to describe the optical behaviors of bio-tissue, we have to use the imaginary scattering and absorption properties. Meanwhile, an apparent index of refraction, or average refractive index has to be introduced to solve various boundary and temporal problems. Two possible measurement methods in which the experimental creativity is reflected are provided. We applied one of experimental setups to study the thermal response of refractive index of bio-tissue. Experimental results suggest that the index be temperature dependent on the process of heating. The tissues used in these experiments were porcine muscles. These measurements were taken at the 632.8nm. The index of refraction keeps stable levels (1.364+-0.001) below 36 Celsius degrees and (1.387+-0.005) above 60 Celsius degrees, respectively, but increases with an increase in temperature from 36 to 60 Celsius degrees. The heating and cooling procedures are irreversible in optical property of tissue.