动态光热参数情形下激光牛肌肉组织光热响应模拟

以牛肌肉组织为模拟对象,考虑到其光热光学和热学参数对温度的依赖性,运用有限元方法模拟了激光在牛肌肉组织中的传输以及动态热响应过程.通过数值求解热传输方程,得到牛肌肉组织内部的温度场分布,并与静态光热参数情形下的结果进行了比较.结果表明:若不考虑光学参数以及热学参数随温度变化的影响,将高估牛肌肉的温升;与热学参数相比,动态光学参数更大程度地影响牛肌肉组织的温度响应;在激光辐照的过程中,牛肌肉组织表面附近将会形成一个光学屏障,影响组织表面和内部的光子数分布,该结论通过Monte-Carlo方法模拟组织内部光子数的分布情况得到了验证.

Numerical Simulation of Opto Thermal Response of Laser Irradiated Bovine Tissue for Dynamically Changed Optical and Thermal Properties

The effect of optical and thermal properties dynamically changed with temperature on the optical thermal response of laser irradiated bovine tissue was studied and the finite element method was employed. The simulation result shows that ① the temperature increase will be overestimated when both optical parameters(μa and μs) and thermal parameters（c, k and ρ）are assumed to be constant; ② compared with thermal properties, dynamical optical properties will cause a greater degree of influence of bovine tissue temperature response; ③ during the irritation of laser, there will form an optical barrier near the surface of bovine tissue, which will affect the distribution of the photon within the bovine tissue and this result was proved by Monte Carlo method.