Investigation of Glucose Non-Invasive Measurement Based on NIR Laser

Abstract

Near-infrared (NIR) diffuse reflectance spectroscopy represents a feasible and promising approach to the noninvasive prediction of blood glucose concentration. This paper experimentally studied and proposed a novel method to develop a stand-alone measurement system, in which laser beams at several particular wavelengths are collimated and illuminated a sample with low-energy NIR by an optical fibre probe, and the diffused reflectance from the sample is collected by a detector. The experimental scheme of the measurement system has been demonstrated to be reasonable and suitable for detecting the change of diffuse reflected absorbance from phantoms and finger tissue. The experimental results have presented the good correlation between the diffuse reflected absorbance and glucose concentration at several particular wavelengths. The spectra lines are perfectly separate from each other at different glucose concentration in vitro. Obvious differences exist in the diffuse reflected absorbance for different glucose concentration. According to the testing standard of the Oral Glucose Tolerance Test (OGTT), the dynamic changes, which the diffuse reflected absorbance from tissue is accompanied with the change of the glucose concentration, have been explored by taking a certain amount oral glucose solution. The results have presented that the sensing system proposed is already able to sense the glucose change from fingertip tissue though the overlapping spectra are encountered. Also, the temperature effect of the sample on the diffuse reflected absorbance of the glucose has been taken into consideration