Internal floating reference method for noninvasive measurement of blood glucose with near-infrared spectroscopy

Weak signal and great background variation have been the major challenges for noninvasive measurement of blood glucose. Two kinds of noise are analyzed, and it is found out that, when instruments achieve a high level of signal to noise ratio, physiological variation other than glucose concentration becomes the dominant over instrument noise. After analyzing the sensitivity of glucose concentration on diffuse reflectance spectroscopy at different source-detector separation, floating-reference method is proposed firstly. This method discusses how to extract signal relating to glucose and signal only relating to background variation respectively, by making use of two special points, reference point and measuring point. Experiments on phantom and Monte Carlo simulations have been performed to validate the feasibility of floating-reference method.