DEVELOPMENT OF NON-INVASIVE BLOOD GLUCOSE MEASUREMENT BY FOURIER TRANSFORM INFRARED SPECTROSOPIC ANALYSIS THROUGH THE MUCOUS MEMBRANE OF THE LIP USING CHALCOGENIDE OPTICAL FIBER SYSTEM

采用衰减全反射棱镜傅里叶变换红外光谱法，研究了通过唇粘膜无创测量血糖的方法。为了实现ATR棱镜到唇粘膜的容易附着和容易控制ATR棱镜到唇粘膜的附着压力，使用在光纤的尖端中内置有ATR棱镜的硫属化物光纤。在通过嘴唇粘膜的光谱中发现了与葡萄糖溶液相同的在1080和1033 cm 2波数处的葡萄糖特异性峰<-1>。当ATR棱镜对唇粘膜的压力为6.7×10^3 dyn/cm ^2时，一天内测量值的变异系数为3.8%，一天之间测量值的变异系数为5.4%。为了消除基线漂移和除葡萄糖以外的身体成分的干扰，评价了餐后状态下测量的光谱与空腹状态下获得的背景光谱之间在1080 cm-1处的吸光度差作为个体特征。在静脉内脉冲注射葡萄糖后，在1080 cm 2处的吸光度差很<-1>好地跟随血糖浓度的变化，延迟时间为4分钟。在每日血糖监测中，吸光度差值与空腹以上血糖浓度的升高呈高度显著相关（r=0.920，P&lt;0.01）。从这些实验中，有人建议，FT-IR光谱与硫族化物光纤可以是有用的临床上通过唇粘膜的葡萄糖的非侵入性监测。

Using Fourier transform infrared (FT-IR) spectroscopy with attenuated total reflection (ATR) prism, non-invasive blood glucose measurement through the mucous membrane of the lip was investigated. To achieve easy attachment and easy control of attachment pressure of ATR prism to the mucous membrane of the lip, the chalcogenide optical fiber with ATR prism built in the tip of the optical fiber was used. The same glucose specific peaks at wave numbers of 1080 and 1033 cm^<-1> as glucose solutions were found in a spectrum through the mucous membrane of the lip. With a constant pressure of ATR prism to the mucous membrane of the lip at 6.7×10^3 dyn/cm^2, coefficients of variation of measurements within a day and of day-to-day measurements were 3.8 and 5.4%, respectively. To eliminate baseline drifts and interference of body constituents other than glucose, the difference absorbancess at 1080 cm-1 between spectra measured at postprandial state and background spectrum obtained at fasting state as an individual characteristic were evaluated. Following intravenous pulsatile injection of glucose, the difference absorbancess at 1080 cm^<-1> nicely followed to the changes in blood glucose concentrations with a time delay of 4 minutes. In daily blood glucose monitoring, highly significant correlation between the difference absorbancess and increases in blood glucose concentrations above fasting level was obtained (r=0.920, p<0.01). From these experiments, it was suggested that FT-IR spectroscopy with the chalcogenide optical fiber could be useful clinically for non-invasive monitoring of glucose through the mucous membrane of the lip.