【作者】 李靖瑶；

【导师】 李刚；

【作者基本信息】 天津大学 ， 生物医学工程， 2009， 硕士

【摘要】 所谓高散射物质即其有相对较高的散射系数。高散射物质的定量分析主要分为两个部分。首先是物质本身光学参数的测量,物质的光学参数是物质的根本属性之一,比如物质的散射系数,吸收系数,各项异性因子等,同时是分析物质成份的重要依据,尤其生物组织的光学参数测量是生物光子学领域研究的关键基础,在医学诊断和治疗领域中有着广泛的应用前景。物质的每种成分都有特定的光学特征,为光谱定量分析提供了基础,其次是通过物质的光学参数对其成分进行测量,通过物质光谱携带的信息来区分不同浓度的同种物质,以及测量它们的含量。本文从定量分析的两方面结合多光程长的测量方法对高散射物质的光学特性进行研究,本课题已经完成的主要工作包括:1)为了提高高散射物质中蒙特卡罗仿真算法的运算速度,在Wang等提供的适于多层组织模型研究的MCML算法的基础上加以改进,分别针对一般光电传感器以及光纤传感器作为接受器件时,提出了两种不同的模型修改方法,通过增加约束条件以及进行近似处理,大幅度提高了蒙特卡罗仿真的速度。2)自行搭建多光程长实验平台,其通过微米位移机构实现不同光程长的测量,以及对高散射物质光学特性的研究,通过对单一波长的分析得出物质的吸收系数与约化散射系数,并通过蒙特卡罗模型进行验证。3)应用偏最小二乘(PLS)方法,对高散射物质进行浓度测量的研究,使用intralipid溶液与India ink配制不同浓度共21种溶液,采用单光程长与多光程长的方法对实验样本进行测量,对单光程长与多光程长方法得到的实验数据进行对比分析,分析结果表明多光程长方法的浓度测量精度远高于单光程长方法,尤其对于India ink,多光程长浓度测量精度要比单光程长浓度测量精度高一个数量级。4)血液成分测量技术一直是近年来生物医学领域的研究热点。目前应用的血液成分检测均是针对血清、血浆或模拟样品的,较少以全血作为光谱测量样本。通过多光程长的方法对全血在可见-近红外区域进行光谱测量,替代了常规使用的血球记录仪与生化分析仪等,能够实现简单、低成本、快速的血液成分检测并且为动态光谱无创血液成分的测量提供依据。更多还原

【Abstract】 The research of the high scattering matters which have the higher scattering coefficient quantitative analysis consists of the measurement of the optical parameters and measurement of the component via the optical parameters. The optical parameters of the matters is the basic attributes, for instance, the scattering coefficient, absorption coefficient, anisotropic factor and so on. The optical parameters are important basis of the analysis of the maters components, especially, the optical parameters mearsurement of the biological tissue which is the key basis of the bio-photonics in the medical diagnostics and treatment fields. The optical characteristics of the each content of the matters are different, which is the basis of the quantitative analysis of the spectra. To the latter, the qualitative analyses distinguish the same matters and measure contents via the information of the spectra. The high scattering matters optical attributes was researched in the two aspects of the quantitative analysis combined with the multi-optical path method. The major works of this subject has been completed as follows:1) In order to improve the simulation speed of the Monte Carlo simulation, the Monte Carlo simulation which was put forward by Wang was improved. The two different simulation methods were employed to improve the generally receiving method and the fiber sensor receiving method. The constraint condition and approximate processing were employed; therefore the simulation speed is improved greatly.2) The multi-optical path experimental platform was design, which could implement the measurement of the different optical path, to the research of the optical parameters of the high scattering matters. The absorption coefficient and scattering coefficient could be obtained via analysis of the one wavelength and the Monte Carlo simulation was employed to verify the results.3) The PLS method was employed to measurement the concentration of the high scattering matters, the sample was the mixed solution of intralipid and India ink which was different concentration and 21 kinds totally. Compared with the fix optical path method, the measurement precision of the multi-optical path method was better, especially, the precision of the ink of multi-optical path method was improved one magnitude than the fix optical path method.4) The measurement of the blood components is the research focus of the biomedical field. The researches are focus on serum, plasma and simulation sample at present, however, the whole blood is rare. The spectra measurement of the blood components in VIA-NIR field is instead of the blood corpuscle recorder and biochemical analyzer which are generally employed. This method can implement simple, low cost, fast measurement of the blood components and provide evidence for the non-invasive measurement of blood compositions based on dynamic spectroscopy.更多还原