近红外光在脂肪乳和葡萄糖混合溶液介质中传播,在介质表面形成漫反射光,稳态情况下,检测位置处检测的漫反射光包含了全部的弹道光、蛇行光与漫散射光,其中部分弹道光和漫散射光降低了葡萄糖浓度的检测精度。通过蒙特卡洛模拟方法分别对10%和3%的intralipid-葡萄糖溶液进行时域模拟,分析统计不同检测位置漫反射光的不同光程组成,对时间扩展曲线的峰值时间与平均飞行时间范围内的漫反射光子进行检测能够提高浮动基准位置即漫反射光强度对葡萄糖浓度最不灵敏的检测位置的检测精度,同时,这部分光子在漫反射光强的极大值处提高了漫反射光强与葡萄糖浓度的线性相关系数,抽取这部分光程的漫反射光在极大值位置提升了对葡萄糖浓度的检测灵敏度。
Near-infrared photons propagate in the mixed solution of intralipid and glucose and form diffuse reflection. In steady state, the scattered photons at the detection spot include ballistic photons,quasi-ballistic photons, and scattered photons, and part of ballistic photons and scattered photons decrease the detection accuracy of glucose concentration. By Monte Carlo time-domain simulations of 10% and 3%intralipid-glucose solution respectively, different path-length components of diffuse reflection at different detection spots were statistically analyzed. It is shown that both the peak time of the detection time expansion curve and diffuse reflection photons in the average flying time can improve the detection accuracy of the point of floating reference, where the diffuse reflection is the most insensitive to the glucose concentration. Moreover, these photons increase, at the maximum intensity of diffuse reflection,the coefficients of linear dependency between the intensity of diffuse reflection and glucose concentration.Thus, extraction of the diffuse reflection corresponding to this path-length improves the detection sensitivity of glucose concentration.