Development of a near-infrared spectroscopic system for monitoring urine glucose level for the use of long-term home healthcare

We have been developing a new technique for measuring urine glucose concentration using near infrared spectroscopy(NIRS) in conjunction with the Partial Least Square (PLS) method. In the previous study, we reported some results ofpreliminary experiments for assessing feasibility of this method using a FT-IR spectrometer. In this study, consideringpracticability of the system, a flow-through cell with the optical path length of 10 mm was newly introduced. Accuracy of thesystem was verified by the preliminary experiments using urine samples. From the results obtained, it was clearlydemonstrated that the present method had a capability of predicting individual urine glucose level with reasonable accuracy(the minimum value of standard error of prediction: SEP = 22.3 mg/dl) and appeared to be a useful means for long-termhome health care. However, mean value of SEP obtained by the urine samples from ten subjects was not satisfactorily low(53.7 mg/dl). For improving the accuracy, (1) mechanical stability of the optical system should be improved, (2) the methodfor normalizing the spectrum should be reconsidered, and (3) the number of subject should be increased