Paired-wavelength spectral approach to measuring the relative concentrations of two localized chromophores in turbid media: an experimental study.
Paired-wavelength spectral approach to measuring the relative concentrations of two localized chromophores in turbid media: an experimental study.
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用于测量混浊介质中两个局部发色团相对浓度的配对波长光谱方法：实验研究。
DOI：
10.1117/1.2779349
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发表时间：
2007
影响因子：
3.5
通讯作者：
Fantini,Sergio
中科院分区：
文献类型：
--
作者：
Liu,Ning;Sassaroli,Angelo;Fantini,Sergio
我们提出了一种新的光谱方法，其目的是在量化的相对浓度的两个发色团所包含的缺陷嵌入在混浊介质中的实验测试。我们的光谱方法的基本步骤是（a）在缺陷上执行源和检测器的线性串联扫描;（B）测量由扫描强度中的缺陷引起的最大变化的光谱依赖性;（c）识别这样的最大强度变化相同的一组适当的波长对（λ）;以及（d）测量背景介质的约化散射系数谱。对于每个波长对（，），我们获得两个发色团的相对浓度的测量，其中唯一需要的参数是两个发色团的消光系数和背景散射系数的比率。在一个0.78厘米直径的圆柱体中含有两种测试发色团（蓝色食用色素染料和黑色印度墨水）的混合物中，我们的光谱方法得到的相对浓度值在其实际值的6%以内。虽然我们的配对波长光谱方法通常不适用于任何一对发色团，但它适用于氧合血红蛋白和脱氧血红蛋白，因此适用于生物组织中局部病变的血氧测定。
We present an experimental test of a new spectral approach that is aimed at quantifying the relative concentrations of two chromophores that are contained in a defect embedded in a turbid medium. The basic steps of our spectral approach are (a) perform a linear tandem scan of the source and detector across the defect; (b) measure the spectral dependence of the maximum change induced by the defect in the scanned intensity; (c) identify a set of appropriate pairs of wavelengths (,) at which such maximum intensity changes are the same; and (d) measure the reduced scattering coefficient spectrum of the background medium. For each wavelength pair (,), we obtain a measurement of the relative concentrations of the two chromophores, where the only required parameters are the extinction coefficients of the two chromophores and the ratio of the background scattering coefficients atand. In a mixture of two test chromophores (blue food coloring dye and black India ink) contained in a 0.78-cm diameter cylinder, our spectral approach yielded relative concentrations values that were within 6% of their actual values. Although our paired-wavelength spectral approach is not generally applicable to any pair of chromophores, it is suitable for oxyhemoglobin and deoxyhemoglobin and is thus appropriate for oximetry of localized lesions in biological tissues.