激光辐照下皮肤组织光热响应有限元分析

为了更好地选择临床激光医疗曝光参量,采用有限元数值计算方法,模拟了脉冲激光与连续激光对人皮肤组织的光热作用及导致的温度变化效应,比较了两者的不同,得到了热响应时间及热弛豫时间与组织深度的关系,即组织越深(0～60 μm),其热响应时间(0～4 ms)与热弛豫时间(0.4～12.1 ms)越长;分析了激光脉宽长短对组织升温的影响;建立了评价脉冲间热损失的评价函数δ,并以此对脉冲间隔的选取作了探讨.     

Numerical simulation and experiment of optothermal response of biological tissue irradiated by continuous xenon lamp

A finite element method computation model for analyzing optothermal interaction of polychromatic light and biology tissue is proposed and proven by experiment. A continuous xenon lamp is employed as an example. First, the spectral energy distribution of the xenon lamp is measured and found to be equivalent to a series of quasi-chromatic light with different central wavelengths, different energies, and certain bandwidth. Next, according to the reported thermal and optical parameters of porcine skin and porcine liver, the temporal temperature distributions of these tissues irradiated by each quasi-chromatic light are simulated. Then, the thermal effect is superimposed to obtain the whole optothermal temporal temperature distribution. Moreover, the optothermal response experiments of fresh porcine skin and porcine liver tissues irradiated by continuous xenon lamp are carried out. The results of the simulation and experiment are analyzed and compared, and are found to be commendably matched.