Non-invasive blood glucose measurement using infrared absorption spectroscopy with a CO_2 laser - design for miniaturization

利用衰减全反射棱镜（ATR）分析口腔粘膜的傅里叶变换红外（FTIR）吸收光谱，实现无创血糖测量，是一种长期血糖监测的替代方法。在所有实验中，来自ATR棱镜（硒化锌）的输出由MCT或TGS检测器检测。该技术是基于这样的现象，即在葡萄糖特异性峰处的吸收强度与ATR棱镜附近的样品的非常薄的层内的葡萄糖浓度直接相关。在葡萄糖水溶液中，葡萄糖在1033 cm-1处具有特征吸收<-1>，并且吸收强度与葡萄糖浓度成比例。然而，在血清和全血样品中，红细胞和血清蛋白质干扰葡萄糖的吸收光谱，使基线显著上移。因此，为了消除这些干扰，获得校准曲线的可行性 ...更多信息 用与空腹样品的差吸收光谱研究了艾德。因此，高于空腹样品的吸收强度的增加与高于空腹样品的葡萄糖浓度的增加之间存在高度显著的相关性。从这些实验中得出结论，通过红外光谱法可以定量测量和监测血清和全血样品中的葡萄糖浓度。在通过口腔粘膜的吸收光谱中，通过使用2920 cm^（CH_2带）处的吸收峰作为参考峰来校正由于棱镜附着而引起的光谱变化之后<-1>，通过使用类似的方法观察到吸收光谱的二阶导数与血糖浓度之间的高度相关性。总之，它表明，傅里叶变换红外光谱可以用于通过口腔粘膜的血糖的无创监测。为了提高傅里叶变换红外光谱仪的灵敏度和小型化，采用二氧化碳激光器作为光源。不仅实现了稳定的激光输出，而且还开发了激光束保护系统和激光束发散系统，使我们能够建立基于光谱分析的无创血糖浓度测量。少

The non-invasive glucose measurement by analyzing Fourier transform infrared (FTIR) absorbance spectra through oral mucosa with an attenuated total reflection (ATR) prism was developed as an alternative way of long-term glycemic monitoring. In all experiments, the output from the ATR prism (zinc selenide) was detected by a MCT or TGS detector. The technique was based on the phenomena that the absorption intensity at a glucose-specific peak was directly related to the glucose concentration within a very thin layer of the sample adjacent to an ATR prism. In glucose aqueous solutions, glucose had a characteristic absorption at 1033 cm^<-1> and the absorption intensity was proportional to the glucose concentration. In serum and whole blood samples, however, red blood cell corpuscles and serum proteins interfered with the absorbance spectra of glucose and shifted the base line upward significantly. Therefore, to eliminate these interferences, the feasibility of the calibration curves obtain … More ed by using difference absorbance spectra with those of fasting samples was studied. As a result, highly significant correlation between the increases in the absorption intensities above those of fasting samples and the increases in glucose concentrations above those of fasting samples. From these experiments, it was concluded that by infrared spectroscopy glucose concentrations in serum and whole blood samples could be measured quantitatively and monitored. In absorbance spectra through oral mucosa, after correcting the spectral changes due to the prism attachment by using absorption peaks at 2920 cm^<-1>(CH_2 band) as reference peaks, high correlation between the second derivatives of absorbance spectra and blood glucose concentrations was observed by the use of a similar approach. In conclusion, it was demonstrated that Fourier transform infrared spectroscopy could be useful for non-invasive monitoring of blood glucose through oral mucosa. A carbon dioxide laser, furthermore, was introduced as a light source in Fourier transform infrared spectrometer for miniaturization and improvement of the sensitivity. Not only the achievement in stable output of laser but also the development of a protection system against laser beam and a laser beam divergence system enabled us to establish the non-invasive measurement of blood glucose concentrations based on spectral analysis. Less