Development of non-invasive blood glucose measurement system : Application of laser absorption spectroscopy with an ATR prism

作为葡萄糖生物传感器长期监测血糖的一种替代方法，无创血糖检测系统应运而生。本实验应用锌硒衰减全反射棱镜红外吸收光谱(傅里叶变换)测定了血清、血浆和全血中的葡萄糖浓度。通过皮肤(指尖)和粘膜(嘴唇)也获得了吸收光谱。1)葡萄糖在1033和1080 cm~(-1)~(-1)附近有一个特征吸收峰。测量信号与葡萄糖浓度成正比。当以1033或1080厘米处的吸光度强度或970至1130厘米之间的积分吸光度强度来测量时，生理浓度的尿素和尿酸不干扰葡萄糖的吸收峰。然而，红细胞、血清白蛋白和胆固醇对谷氨酸…的吸光度有影响3)当与空腹血清和全血样品表示吸光度差时，可以定量测量血清(血浆)和全血样品中的葡萄糖浓度，以消除对血球和葡萄糖以外的代谢物的干扰。4)在通过皮肤和粘膜的吸收光谱中也观察到对葡萄糖分子的特征吸光度。进一步的研究需要开发计算机辅助校准算法，使通过皮肤和粘膜的吸收光谱能够定量测量葡萄糖浓度。应用激光系统作为光源，可以提高测量的灵敏度和能源的稳定性，虽然开发复杂的测量系统将是一项关键技术，但这种方法在不久的将来可能会非常有用地用于糖尿病患者的血糖监测系统。较少

As an alternative way of long-term glucose monitoring with glucose biosensor, the non-invasive blood glucose mesurement system has been developed. In this experiment, the infrared absorption spectroscopy ( with Fourier transformation ) with zinc-selenium attenuated total reflection ( ATR ) prism, was applied to measure glucose concentrations in samples of serum, plasma and whole blood. Absorption spectra through skin ( finger tip ) and mucous membrane ( lip ) were also obtained.1) Glucose showed a characteristic absorbance at peaks with the wave numbers near 1033 and 1080 cm^<-1>. Measured signals were proportional to glucose concentrations. When measured either by the intensity of absorbance at 1033 or 1080 cm^<-1>, or the integrated intensity of absorbance between 970 and 1130 cm^<-1>.2) Urea and uric acid at physiological concentrations did not interfere with the peaks of absorbance of glucose. However, red blood cells, serum albumin and cholesterol affected on the absorbance of glu … More cose at wave number of 1080 cm^<-1> , and shifted the base-line upward significantly.3) Glucose concentrations in serum ( plasma ) and whole blood samples could be measured quantitatively when expressed as difference absorbance with fasting serum and whole blood samples in order to eliminate these interferences with blood corpscles and metabolites other than glucose.4) The characteristic absorbances to glucose melecule were also observed in the absorption spectra through skin and mucous membrane.Further studies are necessary to develop the computer assisted calibration algorithm which enables to measure glucose concentrations quantitatively from the absorbance spectra through skin and mucous membrane. Application of laser system as light source might allow an improvement in measuring sensitivity and also stability of energy source.Although the development of sophisticated measurement system will be a key technology, this method might be quite useful for monitoring system of glucose in diabetics in near future. Less