Determining Glucose Levels From NIR Raman Spectra of Eyes

A developmental noninvasive method of determining the concentration of glucose in blood is based on (1) the acquisition of a near-infrared (NIR) Raman spectrum from the aqueous humor of an eye, (2) analyzing the spectrum by a combination of techniques described below, and (3) recognition that the glucose level in the aqueous humor of the eye is about 80 percent of that in the blood 30 minutes before the spectrum was acquired. More specifically, what the analysis yields is a probabilistic indication that the glucose concentration represented by the Raman spectrum lies in one of three ranges of physiological interest; hypoglycemic (5.8 mM). The method involves less NIR laser power and shorter data-collection times than have been used in previous efforts to use Raman scattering to measure glucose concentrations in blood.