Next Step of Non-invasive Glucose Monitor by NIR Technique from the Well Controlled Measuring Condition and Results

Abstract

Although non-invasive glucose measurement techniques based on near-infrared (NIR) spectroscopy have been interested for over 20 years, a reliable non-invasive glucose monitoring method has not been established yet. Many hurdles are remained to be solved to extract extremely small glucose information from the complicated NIR spectra. In addition, there are also some ambiguous time-dependent physiological processes, which make the explanation of the model more difficult especially in the universal calibration. In this paper, the optical consideration in instrument to improve the SNR is discussed first, which is a critical way to detect small analyte signal. Then an optical measuring conditions reproducible system is used to reduce the noise from human-spectrometer interface. And an optical probe is designed according to the Monte Carlo simulations to measure the dermis selectively to eliminate the noise from human tissue. Finally, with the well-controlled measuring conditions, the in vivo result of single person using the leave one out cross validation within the single day is quite satisfactory. However, the validation results using the validation set from different day are not so good. Further research and extensive model validations are needed to determine if the model is truly based on the glucose information.