The Analysis Methods Of Diffused Reflection And Transmission Spectral From Earlobe For Non-invasive Blood Glucose Sensing By NIR Spectroscopy

With the increasing number of people with diabetes,the research on non-invasive blood glucose detection methods becomes very important and valuable.What's more,the Near-infrared spectroscopy has been widely used to research the human body composition detection.But due to the human complex physiological conditions,blood components,the external environment and many other factors,the measured spectral data is difficult to accurately reflect the glucose information and thus may affect the accuracy of measurement.To reduce this influence,this paper systematically studied the diffused reflection spectrum and diffused transmission spectrum from the human earlobe and Monte Carlo(MC)simulation data of the single-skin model and five-layskin model,what's more,analyzed the impact of the different earlobe thickness on the diffused reflection spectrum and diffused transmission spectrum,and meanwhile analyzed and compared with their two-dimensional correlation of all spectrum.Firstly,this thesis reviews the development of non-invasive blood glucose monitoring during the recent years,introduces the basic principles of non-invasive blood glucose monitoring with human body and the theoretical basis of light and biological tissue interactions,meanwhile,also analyzes the advantages of choosing human earlobe as the measurement site,and then briefly describes the acquisition method of diffused reflectance spectrum and diffused transmittance spectrum of human earlobe.Secondly,the signal-to-noise ratio(SNR)of the spectrum acquisition system set up by group is analyzed in this thesis.And then,the diffused reflectance spectrum and the diffused transmittance spectrum of different volunteer in natural state are collected and analyzed their two-dimensional correlation spectroscopy.And the characteristic information of glucose is found at about 1220 nm and 1330 nm.The experimental results are compared with the Monte Carlo simulation data of the single-skin model and five-lay-skin model within different thickness,and the results show that the experimental results and the simulation results are very close;and the impact of the earlobe thickness to the diffused transmittance spectrum is more obvious: with the increase of the earlobe thickness,the diffused transmittance light intensity may be decrease.However,the impact of the earlobe thickness to the diffused reflectance spectrum is less obvious: with the increase of the earlobe thickness,the diffused reflectance light intensity remains substantially unchanged and only fluctuated in the range of 1000-1300 nm.Finally,two synergistic methods of diffused reflection spectrum and the transmission spectrum are proposed,which are analyzed are compared respectively for simulation experiment and human earlobe experiment.And the result indicates that it can enhance the strength of the effective signals to some extent,and what's more,it also has a very important significance of promoting the non-invasive blood glucose monitoring technology for further development.