Hoffmann J, Lübbers D W, Heise H M
Max Planck Institut für Molekulare Physiologie, Dortmund, Germany.
Phys Med Biol. 1998 Dec;43(12):3571-87. doi: 10.1088/0031-9155/43/12/014.
Reflectance spectrometry is a useful tool for studying in vivo kinetic changes in the oxygen saturation of haemoglobin and myoglobin as well as the redox state of cytochromes. A method is given which allows the quantification of tissue reflectance spectra using multicomponent analysis. This method utilizes the Kubelka-Munk theory for modelling the measured tissue spectra. To test this approach, reflectance spectra of a haemoglobin-free perfused guinea pig heart were measured by a fast scanning spectrophotometer (100 spectra/s, spectral resolution 1.0 nm) and evaluated using the component absorbance spectra measured separately. A relative mean spectral residual error of 0.15% was achieved by least-squares fitting. Using statistical error propagation, oxygenation of myoglobin is obtained within a relative precision of 1%, and the redox state of cytochromes aa3 and c are determined simultaneously within a margin of 3%; the results for the redox-state of cytochrome b, however, are less precise. Special component error functions are presented to provide a reliability measure for the concentration prediction using this multicomponent assay. The consistency of the theory and the component absorptivity data is tested by regressing the actual concentrations obtained for each of the redox pair components during the various states of tissue oxygenation. A method is described for the recognition and reduction of systematic errors.
反射光谱法是研究血红蛋白和肌红蛋白氧饱和度以及细胞色素氧化还原状态体内动力学变化的有用工具。本文给出了一种使用多组分分析对组织反射光谱进行定量的方法。该方法利用库贝尔卡-蒙克理论对测量的组织光谱进行建模。为了验证这种方法，用快速扫描分光光度计（100光谱/秒，光谱分辨率1.0纳米）测量了无血红蛋白灌注豚鼠心脏的反射光谱，并使用单独测量的组分吸收光谱进行评估。通过最小二乘法拟合，相对平均光谱残余误差达到0.15%。利用统计误差传播，肌红蛋白氧合的相对精度为1%，同时细胞色素aa3和c的氧化还原状态在3%的误差范围内确定；然而，细胞色素b氧化还原状态的结果精度较低。提出了特殊的组分误差函数，为使用这种多组分分析的浓度预测提供可靠性度量。通过对组织氧合不同状态下每个氧化还原对组分获得的实际浓度进行回归，检验了理论与组分吸收率数据的一致性。描述了一种识别和减少系统误差的方法。
