脉冲响应函数在Monte Carlo模拟中的应用研究

MonteCarlo方法是研究复杂面光源入射条件下光在生物组织分布规律的唯一有效手段,但直接的MonteCarlo模拟存在计算量大、收敛速度慢的问题。通过引入生物组织脉冲响应函数的概念,利用卷积方法计算光在穿过组织一定深度后的分布规律,编制了相应的程序并进行了大量计算机模拟,在此基础上,提出了一种对模拟结果进行评价的方法,利用该方法分析了光源离散量与脉冲响应函数模拟量对光场分布计算结果的影响,证明基于脉冲响应函数的MonteCarlo模拟可以极大地提高计算效率和收敛速度。

The application of impulse response function in Monte Carlo simulation of light distribution in biological tissues

Monte Carlo method is the only effective solution in the study of light distribution in biological tissues irradiated by a complex surface source. However,direct Monte Carlo simulation demands large computational capacity because of its low rate of convergence.In this paper,the concept of impulse response function in biological tissues is introduced,thus light distribution in certain depth of the biological tissue can simply be obtained by calculating the convolation of incident source function and the impulse response function. On the basis of computer simulation,a criterion is proposed to evaluate the results of Monte Carlo simulation. By means of the criterion,the influence of impulse response function and dispersed quantity of the light source is analysed comprehensively,which shows that the calculating efficiency is greatly improved by the introduction of impulse response function in Monte Carlo simulation of light distribution in biological tissues.