DETERMINATION OF PHYSIOLOGICAL LEVELS OF GLUCOSE IN AN AQUEOUS MATRIX WITH DIGITALLY FILTERED FOURIER-TRANSFORM NEAR-INFRARED SPECTRA
DETERMINATION OF PHYSIOLOGICAL LEVELS OF GLUCOSE IN AN AQUEOUS MATRIX WITH DIGITALLY FILTERED FOURIER-TRANSFORM NEAR-INFRARED SPECTRA
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DOI：
10.1021/ac00213a021
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发表时间：
1990-07-15
影响因子：
7.4
通讯作者：
SMALL, GW
中科院分区：
文献类型：
--
作者：
ARNOLD, MA;SMALL, GW
本文描述了用近红外（NIR）吸收光谱法测量水溶液中临床相关葡萄糖浓度的方法。以4400 cm-1为中心的葡萄糖带用于该分析。用傅里叶变换光谱仪在5000 ~ 4000 cm-1的频率范围内采集近红外光谱。在光谱仪的光程中放置窄带通光干涉滤光片，以消除超出该限制范围的光。这种配置提供了2.9倍的频谱噪声减少，利用检测器的动态范围，仅为光通过过滤器传输。此外，描述了一种新的光谱处理方案，用于从所得吸光度光谱中提取葡萄糖浓度信息。该方案的关键组成部分是一个数字傅立叶滤波器，它可以从频谱中去除高频噪声和低频基线变化。数值优化程序用于确定该傅里叶滤波器的高斯型频率响应函数的最佳位置和宽度。动态面积计算，加上简单的线性基线校正，从处理后的光谱中提供与葡萄糖浓度在1-20 mM范围内线性相关的综合面积。线性校准模型准确预测了一系列测试溶液中的葡萄糖水平，总体平均误差为2.5%。基于标定模型参数的不确定性和积分区域大小的可变性，预测葡萄糖浓度的总体不确定性估计为7.8%。
A procedure is described for the measurement of clinically relevant concentrations of glucose in aqueous solutions with near-infrared (NIR) absorbance spectroscopy. A glucose band centered at 4400 cm-1 is used for this analysis. NIR spectra are collected over the frequency range 5000-4000 cm-1 with a Fourier transform spectrometer. A narrow-band-pass optical interference filter is placed in the optical path of the spectrometer to eliminate light outside this restricted range. This configuration provides a 2.9-fold reduction in spectral noise by utilizing the dynamic range of the detector solely for light transmitted through the filter. In addition, a novel spectral processing scheme is described for extracting glucose concentration information from the resulting absorbance spectra. The key component of this scheme is a digital Fourier filter that removes both high-frequency noise and low-frequency base-line variations from the spectra. Numerical optimization procedures are used to identify the best locaation and width of a Gaussian-shaped frequency response function for this Fourier filter. A dynamic area calculation, coupled with a simple linear base-line correction, provides an integrated area from the processed spectra that is linearly related to glucose concentrations over the range 1-20 mM. The linear calibration model accurately predicted glucose levels in a seriesd of test solutions with an overall mean percent error of 2.5%. Based on the uncertainty in the parameters defining the calibration model and the variability of the magnitudes of the integrated areas, an overall uncertainty of 7.8% was estimated for predicted glucose concentrations.