简易脑功能近红外光谱系统设计  

A Simple Design of Functional Near-Infrared Spectroscopy System

作　　者：徐刚[1] 李小俚[1] 刘晓民[2] 

机构地区：[1]北京师范大学认知神经科学与学习国家重点实验室,北京100875 [2]北京工业大学电子信息与控制工程学院,北京100124

出　　处：《光谱学与光谱分析》2015年第2期552-556,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(61273063)资助

摘　　要：功能近红外光谱(functional near-infrared spectroscopy,fNIRS)是一种无损的脑成像技术,经过20年的发展,已广泛应用于认知神经科学研究领域。基于神经血管耦合机制,与功能相关的大脑神经活动增强会引起局部脑血流量的升高,进而引发血液中氧合血红蛋白与脱氧血红蛋白浓度相应的变化,间接反映了大脑中神经激活程度。研制了一套基于多功能采集卡的单通道连续波fNIRS系统。在该系统中,选择激光二极管作为光源具有较好的单色性和较低的发散角,690和830nm波长的组合有助于降低发色团之间的串扰。频分复用技术用于区分来自不同光源的信号,同时也消除了环境光、工频干扰等特定频率的噪声源。利用LabVIEW软件平台实现了光源的时序控制、自动增益调节、数字正交相干解调,以及数据可视化与存储等功能。屏气和心算实验结果表明,该系统可用于监测大脑局部血红蛋白浓度的实时变化,并可以检测与高级脑功能相关的激活。With the development in last twenty years, functional near-infrared spectroscopy （fNIRS） is a non-invasive brain ima- ging technique which widely used in cognitive neuroscience studies. Based on mechanism of neurovascular coupling, increased functional neural activities in brain induce higher regional cerebral blood flow, which will cause relative concentration change of oxygenated and deoxygenated hemoglobin. In this paper, a single channel continuous wave fNIRS system based on multi-function data acquisition board was proposed. With the benefits of narrow spectral peaks and low divergence, laser diodes provided a bet- ter accuracy for measurement with optimal dual-wavelength of 690 and 830 nm. Frequency multiplexing technique was used to distinguish light sources from different emitters, and remove environmental stable interference sources such as ambient light and line power noise as well. LabVIEW was used to design graphical user interface with functionalities including source sequence schedule, auto gain setting, digital in-phase and quadrature demodulation, data visualization and storage. The experimental re- sults during holding breath and mental arithmetic task indicated that our system was capable of monitoring regional concentration change of hemoglobin in real time, and detecting activation associated with advanced brain functions.

关 键 词：功能近红外光谱 氧合血红蛋白 脱氧血红蛋白 脑功能激活 频分复用 

分 类 号：O433.4[机械工程—光学工程]