皮肤真皮层厚度对近红外光谱法无创血糖测量影响的仿真  

Simulation of the Effect of Dermal Thickness on Non-Invasive Blood Glucose Measurement by Near-Infrared Spectroscopy

作　　者：刘文博 刘瑾[1] 韩同帅[1] 葛晴 刘蓉[1] LIU Wen-bo;LIU Jin;HAN Tong-shuai;GE Qing;LIU Rong(State Key Laboratory of Precision Measuring Technology and Instruments,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072

出　　处：《光谱学与光谱分析》2023年第9期2699-2704,共6页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(81971657,81871396)资助。

摘　　要：在基于近红外光谱法的无创血糖测量领域,受人体皮肤状态波动的影响,血糖预测模型无法长时间使用,极大地限制了该方法在临床上的应用。皮肤血流灌注是与人体生理状态密切相关的参数,直接影响着皮肤中水分的流动,它还难以像温度、压力那样借助外部手段进行控制。在皮肤光谱的测量中,血流灌注会通过水分的迁移间接影响真皮层的厚度,并使得光谱产生较大变化。借助蒙特卡洛模拟方法仿真了在1000~1700 nm波段真皮层厚度变化±30μm时三层皮肤的漫反射光强、光子穿透深度与平均光程,研究了真皮层厚度变化后的光谱变化规律。对两个光源-探测器距离下的衰减度进行差分,用于消除真皮层厚度变化的影响,对1000~1700 nm的波长均给出了适宜的差分测量距离。发现1200 nm波长附近,当真皮层厚度变化时,漫反射衰减度在每个测量距离下的变化都非常小,因此是较适宜的测量波长。而对于水的吸收峰1450 nm附近的波长而言,漫反射衰减度随着光源-探测器距离的增加而变大,且在一定范围内急剧变化;因此,应避免选择这些光源-探测器距离。对于常用的血糖测量波长1200、1300及1600 nm波长而言,光源-探测器距离可选在小于0.1 cm或大于0.4 cm的范围,此处漫反射衰减度变化随着光源-探测器距离变化较缓慢,采用差分处理可较好地消除真皮层厚度变化对光谱的影响。考虑到不同光源-探测器距离下对应的真皮层光子百分比不同,可选择主要对应于真皮层的光源-探测器距离,该工作采取80%真皮光子百分比为界限。综上,综合现有仪器能达到的测量精度水平,对于1200、1300和1600 nm波长,可选择0.03~0.1 cm范围内的两个光源-探测器距离进行差分测量,可以较好地抑制真皮层厚度变化的影响,从而有效减小皮肤血流灌注变动的影响。In the non-invasive blood glucose measurement(NBGM)based on near-infrared spectroscopy,the established blood glucose prediction model could not work well for a long time as it is greatly affected by the fluctuation of human skin status.It can be a limitation for the real clinical application of the method.Cut aneous blood perfusion(CBP)is a parameter closely related to the physiological state of the skin,which directly affects the water flow in the skin.It is also difficult to be controlled by external means like the approaches to control the temperature or contacting pressure.As for measuring skin spectra,CBP affects the thickness of the dermis indirectly by changing the migration of water,and the skin spectra change greatly.In this paper,Monte Carlo simulation is used to simulate the diffuse light intensity,photon penetration depth and average optical path of a three-layered skin model when the thickness of the dermis changes±30 microns at 1000~1700 nm.The spectral changes were investigated.The differential processing can be used on the diffuse attenuations of two neighbored source-detector separations(SDSs)to eliminate the influence of dermis thickness change.The appropriate SDSs are acquired to perform the differential measurement for 1000~1700 nm wavelengths.It has been found that 1200 nm should be an optimal wavelength to get away from the affection from the varying dermis thickness because the attenuation at all SDSs varies little.At the wavelengths near 1450 nm,where the water has strong absorption,the attenuation will change rapidly with SDS in certain SDSs,requiring a critical SDS selection.For the commonly used wavelengths in NBGM,1200,1300 and 1600 nm,the SDSs can be set in which is less than 0.1 cm or greater than 0.4 cm since there the attenuation changes slowly with the SDS and the differential on two SDSs can work well to reduce the influence of the change of dermis thickness.Moreover,the SDSs should be selected to primarily sense the information of the dermis considering the different percentage

关 键 词：近红外漫反射光谱法 无创血糖测量 蒙特卡洛模拟 皮肤血流灌注 三层皮肤模型 真皮层厚度 差分测量 

分 类 号：O433.4[机械工程—光学工程]