利用修改的比尔-郎伯定律计算组织吸收对光子平均路径长度的影响（英文）

Effects of tissue absorption on calculation of mean photon path length using modified Beer-Lambert law

在使用修改的比尔-郎伯定律计算组织的吸收系数以及血氧含量时,平均路径长度(MPL)是一个重要的参数,由此参数可得到微分路径因子(DPF),而DPF通常假定为在一定组织吸收范围内是一个常数。通过腿部的光子蒙特卡罗仿真,本论文使用四种方法来估计MPL,并与MPL的原始定义进行对比。仿真结果表明,DPF显著受到组织吸收的影响,表现为10%的数值变化。因此,使用线性模型将比使用修改的比尔-郎伯定律能更好地计算组织的吸收系数以及血氧含量。

The mean path length(MPL)of photons is a critical parameter to calculate tissue absorption coefficient as well as blood oxygenation using modified Beer-Lambert law,where in the differential path factor(DPF)is often assumed as constant over range of tissue absorption.By utilizing the Monte Carlo(MC)simulation of photon migrations in the leg,this study used four approaches to estimate MPL,and compared them with that determined by the MPL definition.The simulation results indicate that the DPF is remarkably affected by tissue absorption,at approximate 10% variation.A linear model is suggested to calculate MPL for measurements of tissue absorption as well as blood oxygenation using modified Beer-Lambert law.