SHANG Yu1,2, GUI Zhi-guo1,2
（1. Science and Technology on Electronic Test & Measurement Laboratory, North University of China, Taiyuan 030051, China； 2. Key Laboratory of Instrumentation Science & Dynamic Measurement (North University of China), Ministry of Education, Taiyuan 030051, China）
Abstract： 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.
Key words： mean path length (MPL); photon Monte Carlo (MC) simulation; modified Beer-Lambert law; tissue absorption
CLD number： O433.1Document code： A
Article ID： 1674-8042（2016）02-0110-05 doi： 10.3969/j.issn.1674-8042.2016.02.003
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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
尚禹1,2， 桂志国1,2
（1. 中北大学 电子测试技术重点实验室， 山西 太原 030051； 2. 中北大学 仪器科学与动态测试教育部重点实验室， 山西 太原 030051）
摘要: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。
关键词:平均路径长度（MPL）； 光子蒙特卡罗仿真； 修改的比尔-郎伯定律； 组织吸收
引用格式：SHANG Yu, GUI Zhi-guo. Effects of tissue absorption on calculation of mean photon path length using modified Beer-Lambert law. Journal of Measurement Science and Instrumentation, 2016, 7(2)： 110-114. ［doi： 10.3969／j.issn.1674-8042.2016.02.003］
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