基于MC模型和Nelder-Mead单纯形算法的时域组织光谱学  

Time⁃Resolved Spectroscopy Based on Monte Carlo Model and Nelder⁃Mead Simplex Algorithm

作　　者：张童 刘东远 高峰[1,2] Zhang Tong;Liu Dongyuan;Gao Feng(College of Precision Instruments and Opto-Electronics Engineering,Tianjin University,Tianjin 300072,China;Tianjin Key Laboratory of Biomedical Detecting Techniques and Instruments,Tianjin 300072,China)

机构地区：[1]天津大学精密仪器与光电子工程学院,天津300072 [2]天津市生物医学检测技术与仪器重点实验室,天津300072

出　　处：《中国激光》2024年第3期138-147,共10页Chinese Journal of Lasers

基　　金：国家自然科学基金(62075156,81971656,62205239)。

摘　　要：生物组织光学参数的无创在体测量是近红外光谱学(NIRS)研究的基础课题之一。在已发展的NIRS方案中,时间分辨测量具备优良的同时反演吸收系数和散射系数的能力,而且近年来该技术的性价比显著提高,获得了更多关注,但其针对分层组织的参数反演在准确性、稳定性和反演速度等方面尚存在一定的局限性。为此,本文提出了一种时域蒙特卡罗模型支持的Nelder-Mead单纯形算法,该算法利用双源探距下的时间分辨漫反射光信号,以循环迭代方式设置不同的基向量,经线性变换后无须求导便可启发式搜索目标函数的最优值,从而实现了高信效度的分层光学参数反演。模拟实验与仿体实验均表明:在组织光学参数反演方面,所提算法的精度优于传统算法,而且该算法具有良好的噪声鲁棒性和临床适应性,为生物组织光学参数的在体测量提供了新方法。Objective Changes in optical parameters can reflect the physiological status of biological tissue and constitute a fundamental and important topic in the field of near-infrared spectroscopy.Compared with the continuous-wave and frequency-domain measurement methods,the time-domain measurement method has the best performance in distinguishing and separating absorption and scattering coefficients,particularly in single-point measurement scenarios.Consequently,the time-domain measurement method is more commonly used to measure changes in optical parameters,also known as time-resolved spectroscopy.Currently,the biological tissue model used for time-resolved spectroscopy inversion schemes often assumes that the biological tissue is a single-layer biological tissue model,which hypothesizes that the optical properties are identical throughout the tissue.Although the single-layer biological tissue model simplifies the complexity of light propagation models and inversion algorithms,it is not very suitable for representing the structure of most human biological tissues;biological tissues at different depths exhibit a layered structure owing to variations in structure and function.Considering the high computational complexity and marginal improvement in accuracy associated with multilayer models,recent research has increasingly focused on the double-layer biological tissue model.Currently,the commonly used double-layer biological tissue model parameter inversion methods face several challenges.First,they require a substantial amount of experimental data from multiple sources and detector separation,resulting in extended overall measurement times.Second,considerable time and effort are required to construct precise databases.Third,the need for iterative differentiation leads to prolonged computation time and lower accuracy.Finally,these methods struggle to handle complex scenarios,such as those in which both layers of tissue parameters are entirely unknown.To address these issues,this study introduces the Nelder-Mead simplex

关 键 词：医用光学 吸收系数 约化散射系数 蒙特卡罗模拟 单纯形算法 时域测量 

分 类 号：O434[机械工程—光学工程]