Abstract
In previous experiments, we demonstrated that by applying infra-red spectroscopy, serum and blood glucose concentrations could be measured quantitatively, if the interferences and base-line drift were subtracted. In this experiment, we have analyzed the spectra of substrates other than glucose and found that absorbance spectra from blood samples were consistent with the compound specta of each component of red blood cell corpuscles, albumin, globulin and glucose. Therefore, to eliminate the base-line drift and interferences, we have applied the subtraction method with the spectrum of fasting sample. The S/N ratio was also improved. Then, highly significant correlations between the intensities and the increases in glucose concentrations for serum or blood samples were obtained. By applying this subtraction method to the spectra through mucous membrane of lip, intensities of absorbance spectra, proportional to glucose concentrations, could be obtained during oral glucose load in a diabetic patient. From these experiment, it was suggested that infra-red spectroscopy is useful for the continuous and non-invasive measurement of tissue glucose concentrations.
