中文摘要：

人体内各种血液生化成分含量的变化是评价健康状况的重要信息。人体皮肤中，血糖、胆固醇等生化成分主要存在于真皮层的血液中，本文通过研究最佳的探测距离，提高真皮层的近红外光谱信号强度，排除表皮层、皮下组织产生的干扰。首先，通过对人体皮肤的组织结构进行分析，计算得到了皮肤各层的组织光学特性参数，以葡萄糖在合频波段吸收峰2270 nm处的组织光学参数为例建立了皮肤的蒙特卡罗模型；然后，利用蒙特卡罗方法模拟了光在皮肤中的传输规律，得到了平均路径长度、平均探测深度以及各层吸收光子能量比例随入射角度、探测距离的变化情况。结果表明，光子以小于45＆#176;角入射时，可以忽略入射角度对光子传输路径的影响。探测距离为1 mm时，真皮层吸收光子能量所占比例最大，同时又能保证探测器接收到较多的能量。本文确定1 mm作为最佳的探测距离，可以有效降低皮肤中其他组织的干扰，获取真皮层中血液的光谱信息，有利于生化成分的近红外无创检测，为后续实验奠定理论基础。

英文摘要：

The present paper studies the best detector-distance to improve the near-infrared spectrum signal intensity of the der-mis layer and eliminate the interference of the epidermis and subcutaneous layer .First ,we analyzed the organizational structure of the skin and calculated the tissue optical parameters of different layers .And we established the Monte Carlo model with the example of glucose absorption peak at 2 270 nm .Then ,we used the Monte Carlo method to simulate the light transmission rules in the skin ,obtaining the average path length ,the average visit depth and the fractions of absorbed energy at each layer with the change in critical angle and detector-distance .The results show that when the photons are incident at an angle less than 45 de-grees ,you can ignore the effect of the incident angle on photon transmission path ,and when the detector-distance is 1 mm ,the fraction of absorbed photon energy by the dermis layer is the largest ,while it can ensure more energy received by detector .We determined that the best detector-distance is 1mm ,which successfully avoids the interference of the epidermis spectral informa-tion and obtains large amounts of blood in the dermis layer ,which is conducive to the near-infrared non-invasive measurement of biochemical components and the subsequent experiments .