一种双波长数字锁相光学拓扑成像系统  

A Dual-Wavelength,Lock-in Optical Topography System

作　　者：高峰[1,2] 陈琛[1] 赵会娟[1,2] 李娇[1] 李峰辉[1] 

机构地区：[1]天津大学精密仪器与光电子工程学院,天津300072 [2]天津市生物医学检测技术与仪器重点实验室,天津300072

出　　处：《纳米技术与精密工程》2014年第1期7-14,共8页Nanotechnology and Precision Engineering

基　　金：国家高技术研究发展计划(863计划)资助项目(2009AA02Z413);国家自然科学基金资助项目(30970775);天津市自然科学基金资助项目(09JCZDJC18200)

摘　　要：光学拓扑成像方法作为现有脑功能成像模态的有益补充,可以直接同时提供脑组织中氧合血红蛋白(HbO2)和脱氧血红蛋白(Hb)的变化信息,对临床诊断和治疗有重要意义.目前推出的光学拓扑成像系统价格昂贵,难以推广,因此设计了一种结构简单、成本较低的双波长数字锁相光学拓扑成像系统.该系统采用数字锁相检测技术从叠加信号中提取各个分信号的幅值信息,并以修正的Beer-Lambert定律为模型计算每对相邻的源点和探测点之间脑组织的吸收系数变化量.对该拓扑成像系统进行了可行性验证和模拟的实验验证,结果表明,该拓扑成像系统不仅能实现双波长同步测量,还能在一定程度上对目标位置进行有效分辨,并准确反映其吸收系数变化趋势,在大脑皮层各调控区的应激反应过程定性研究中具有重要意义.The optical topography technique has been regarded as an beneficial supplement to the other established methods for imaging functional activation in the brain. It can quantify the changes in the con centration of oxyhemoglobin （HbO2 ） and deoxyhemoglobin （Hb） directly and simultaneously, which plays a great role in the clinical diagnosis and treatment. However, the existing optical topography system is too expensive to be popularized. Thus, in this paper an optical topography system with dualwavelength based on digital lockin detection is developed, which is of low cost and simple structure. The system re trieves respective reflection intensity from mixed signals by applying digital, lockin detection technique. By applying the modified BeerLambert law to each pair of adjacent source point and detection point, the change of absorption coefficient in the brain can be measured. A series of feasibility testing experiments and phantom simulating experiments were conducted in vivo. The results show that this optical topography system can measure at double wavelengths simultaneously, and furthermore, it can distinguish the target to some extent and reflect the change of absorption coefficient accurately, which plays a great role in the qualitative research on stress reaction generated in the cerebral cortex control region.

关 键 词：数字锁相检测 光学拓扑 脑功能成像 血红蛋白 

分 类 号：TH789[机械工程—仪器科学与技术]