Tissue Photothermal Coupling Interaction Model Based on Finite Element Analysis

本文基于有限元分析方法，使用COMSOL Multiphysics 4.4软件，将生物组织光传输的物理场与热传输的物理场相耦合，运用间接耦合求解法和全耦合求解法分别模拟了静态光热参数和动态光热参数下生物组织的光分布和温度分布随时间的变化特征；并将静态光热参数和动态光热参数的情况相比较。结果表明：通过分析不同温度的静态光热参数下的光分布和温度分布能定性说明组织光分布和温度分布的变化趋势；使用动态光热参数进行模拟时，随着加热时间的增加，光分布范围和温度分布范围在逐渐变大，入射点的光通量密度和温度在增大，而温度随加热时间的增长变化的越来越慢。同时还表明COMSOL Multiphysics软件能够方便的求出任意时刻的温度分布及此时所对应的光分布。 This paper is based on the finite element analysis method and it couples the physical field of optical transmission with the physical field of heat transfer in biological tissue by using COMSOL Multiphysics 4.4 software. The temporal distributions of light and temperature in biological tissue were studied in the case of statically photothermal parameters and dynamically photothermal parameters by using indirectly coupled solution method and fully coupled solution method, respectively. In addition, the case of statically photothermal parameters was compared with the case of dynamically photothermal parameters. The results present that the change of light distribution and change rate of temperature in tissue can be described qualitatively by analyzing the distribution of light and temperature in the case of statically photothermal parameters of different temperature; the range of light distribution and temperature distribution are increased in the course of heating when the dynamically photothermal parameters were employed. At the same time, the light flux density and temperature of the incident point will be increased, but the change rate of temperature will be decreased when the heating time goes by. It also shows that the temperature profile at any time and the corresponding light distribution can be easily obtained by using COMSOL Multiphysics software.