基于双积分球的宽光谱组织光学参数测量系统与方法研究

摘要

The measurement of tissue optical parameters is the focusing research content of Biomedical Photonics .The optical properties of human tissue are closely related to the physiological and pathological state .In recent years ,the tissue imaging diag-nosis and non-invasive detection of componentsbecome the hot research topics ,applying the tissue optical properties especially the absorption and scattering properties .These provide the basis for the study of optical imaging and the spectrum detection of body composition etc .The Double-Integrating-Spheres (DIS) method can measure the absorption coefficient ,scattering coeffi-cient and so on in vitro tissuesimultaneously .It has the advantages of accurate ,rapid ,large applicable scope .The method applya standard method for measuring the optical parameters .This paper build the wide spectrum measurement system of optical pa-rameters based on DIS and super continuum lasers .Then we analyze the transfer function ,error sources and the best measuring conditions of the system .Finally we establish the correction forward model based on BP-MCML and the inverse algorithm of the optical parameters based on L-M algorithm .The optical parameters of intralipid solution in the wavelength range of 1 100~1 400 nm are measured .The experiment results show that the improved inverse algorithm is accurate .The multiple measurements standard deviation is within 3% .Compared the results of scattering coefficient and absorption coefficient at different wavelengths to the results of other research groups ,the deviation is less than 3.4% .%组织光学参数测量是生物医学光子学的主要研究内容之一 ,人体组织光学性质与其生理病理状态密切相关.近年来 ,利用组织光学特性 ,特别是吸收与散射特性进行组织成像诊断及无创成分检测成为生物医学光子学领域研究热点 ,为肿瘤早期诊断、代谢动态监护及光动力治疗等临床应用提供了基础.双积分球方法能够同时测量离体组织吸收系数、散射系数等 ,具有测量准确、快速 ,适用范围大等优点 ,作为光学参数测量的标准方法得到广泛研究与应用.利用双积分球及超连续激光器搭建了宽光谱的组织光学参数测量系统 ,分析了积分球测量传递函数与误差来源及系统最佳测量条件 ,建立了基于BP-MCML的系统校正正向模型与L-M算法的光学参数反构算法.在此基础上 ,测量了1 100~1 400 nm连续宽谱范围内Intralipid溶液光学参数 ,实验结果表明改进后反构算法测量结果比较准确 ,多次测量标准偏差在3% 以内 ,不同波长下约化散射系数及吸收系数测量结果与其他研究小组得到的测量结果对比 ,偏差小于3.4% .