用于无创血糖检测的调频连续波激光雷达技术理论分析  

Analysis of Frequency-Modulated Continuous-Wave Lidar Technique for Non-Invasive Blood Glucose Measurement

作　　者：熊冰[1] 魏文雄[1] 何建军[1] 

机构地区：[1]浙江大学现代光学仪器国家重点实验室集成光电子中心,浙江杭州310027

出　　处：《光学学报》2011年第6期183-188,共6页Acta Optica Sinica

基　　金：国家自然科学基金(60788403)资助课题

摘　　要：连续无创血糖检测能够更好地实现对糖尿病的管理和治疗。提出一种利用调频连续波(FMCW)激光雷达技术实现无创血糖测量的方案,通过检测皮肤散射系数的改变来测量血糖浓度的变化。与传统的光学相干层析成像血糖检测法相比,结构更简单,利于实现仪器的小型化、便携化。FMCW激光雷达无创血糖测量系统采用差分干涉的方法,将时域的信号转移到频域,通过分析频域信号斜率来获得被测物体的散射系数。分析了频率调制信号为锯齿波的情况,建立了系统工作过程的数学模型,并讨论了激光器性能对系统分辨率的影响。利用蒙特卡罗方法对类人体组织液进行仿真,分析了不同葡萄糖浓度时信号斜率的变化。仿真结果表明,当葡萄糖浓度增大20 mmol/L时,系统信号斜率下降35%,与米氏散射理论计算值相符。最后介绍了以二氧化硅小球悬浊液作为检测样品的原理验证性实验。从实验的结果可以看出,系统信号斜率与样品散射系数成正比,初步验证了该方法的可行性。Continuous non-invasive glucose monitoring makes the treatment and management of diabetic disease convenient. A non-invasive technique based on the frequency-modulated continuous-wave （FMCW） lidar technique that detects the scattering coefficient of the tissue is proposed. Compared with the traditional glucose measurement method based on optical coherence tomography, the FMCW lidar system has the advantages of simple and compact structure without moving parts, and is easy to realize portable apparatus. It mainly consists of a near-infrared semiconductor tunable laser and a detector, using heterodyne technique to convert the signal from time domain to frequency domain. A mathematical model of the system of sawtooth-wave modulation is established. Factors that affect system resolution are analyzed. Monte Carlo simulations have been performed on the tissue phantoms to investigate the slope of the system signal spectrum under different glucose concentrations. The simulations show that the system signal slope decreases 35 % with a glucose concentration increment of 20 mmol/L, which agrees well with the scattering coefficients calculated by Mie theory. Proof-of-principle simulations and the experiments suggest that the FMCW method has a great potential as a convenient tool for non-invasive glucose measurement.

关 键 词：医用光学 无创血糖检测 调频连续波激光雷达 蒙特卡罗模拟 

分 类 号：TN247[电子电信—物理电子学]