Development of an optical system for monitoring urine substances -Preliminary study of wavelength selection for LED system implementation-

Abstract

We have been developing an optical system for monitoring urinary substances and have already reported in the previous conference about the accuracy in estimating concentration of four urine substances, i.e., glucose (Glu), urea (Ur), sodium chloride (NaCl), and creatinine (Cr), using an FT-IR spectrometer. In that study, PLS analysis was carried out using 236 absorbance data in the selected wavelength regions. In this study, considering practicability of the future system, we tried to select four wavelengths sensitive to urine substances. From the results obtained by the multiple regression analysis using the four wavelength, it was confirmed that high accuracy in estimating concentration of the four substances were attained (correlation coefficient, Glu: 0.966, Ur: 0.998, NaCl: 0.901, Cr: 0.983) suggesting availability of these wavelengths for the future multiple wavelength LED system.