Preliminary Analysis Of Glucose Sensitivity For Single Wavelength Measurement At 1000-1700 Nm

In the non-invasive blood glucose measurement based on Near-infrared diffuse spectroscopy,the changes of optical signal caused by the change of glucose concentration are very small,which is easily interfered by instrument drift,measurement conditions and changes of human physiological background,making blood glucose measurement under single wavelength always a challenge.This paper intends to select the appropriate measurement wavelength and human skin measurement site in the near infrared band of 1000-1700 nm to improve the sensitivity of single wavelength measurement of blood glucose.The specific research contents of this paper include:Firstly,the principle of measuring glucose by near infrared diffuse reflectance spectroscopy based on position differential measurement is introduced,and the parameter-effective attenuation coefficient of glucose measurement by this method in single wavelength is given.This paper mainly uses it to analyze the sensitivity of measuring glucose.It is proposed that the sensitivity of glucose measurement is related to the basic optical parameters of the measured tissue,the variation of optical parameters caused by glucose,and the skin structure.Secondly,the influence of the absorption coefficient and scattering coefficient of the medium on the glucose sensitivity is studied.It is found that the glucose measurement sensitivity is greatly affected by the change of scattering coefficient caused by the change of unit glucose in the short-wave and long wave bands,and is greatly affected by the albedo in the long wave band.At the same time,different Intralipid solutions(2%,4%,10% and 20%,respectively)were used as tissue imitates to simulate the glucose sensitivity.It was found that the glucose sensitivity of 2%Intralipid solution was the highest.Then,the imitation experiment was carried out to verify.Glucose in three kinds of Intralipid solutions(4%,10% and 20%,respectively)were measured by multi-loop fiber optic measurement system,and the sensitivity of glucose was obtained,and the change of sensitivity of glucose in Intralipid solution was verified.Finally,the sensitivity of the three layers of human skin to glucose changes was analyzed,and it was found that the dermis was the most sensitive and the most suitable for measuring blood glucose.Then,the skin with different epidermal and dermis thickness is simulated,it was found that the thinner the epidermis,the greater the sensitivity of glucose measurement,while the effect of dermis thickness on sensitivity was relatively small.Furthermore,the sensitivity of glucose measurement in four parts of human arm,cheek,back of hand and between the thumb and index was compared,and the optical parameters of the arm were beneficial to obtain higher glucose sensitivity.Meanwhile,in the 1000-1700 nm band,the wavelength near 1450 nm has high glucose sensitivity.In conclusion,we analyzed the influencing factors of the sensitivity of the position-based differential diffuse reflectance spectroscopy in the measurement of glucose at single wavelength,and verifies it through the measurement experiment of simulated solution.Finally,the sensitivity of glucose measurement in different parts of human body was simulated and compared.The results of this study can be used for reference in the selection of measurement sites in non-invasive blood glucose measurement.