研制了一套基于近红外三波长的血溏浓度检测系统,其主要由光源、斩波器、探头及锁定放大器组成,3个波长分别为1200、1350和1610nm,探头采用圆-环式设计,并将源探间距设为理论分析的最佳距离3~5mm。对不同浓度葡萄糖水溶液测量表明:吸收差值比D与葡萄糖浓度具有很好的线性相关性,其相关系数为0.972。采用偏最小二乘回归建立预测模型,其预测均方根误为17.08mg/dL,相关系数可达0.997。
A system based on three-wavelength in near-infrared range was designed to detect the blood glucose concentration. The system is composed of a light source,a chopper,a detector and a lock-in amplifier. 1 200 nm,1 350 nm,1 610 nm were chosen in this system. The detector contained ring source and round photodiode. And the distance of source-detector was 3- 5 mm which is derived by theoretic analysis. The result indicated that the ratio of absorption difference D depended on the glucose level linearly,and the relative coefficient was 0. 972. When using partial least square(PLS) to predict,the root mean square error of prediction (RMSEP) was 17.08 mg/dL and the relative coefficient was 0. 997.