高采样率近红外光谱成像系统的调制解调方法  

Modulation and demodulation method of functional near-infrared spectroscopy system with high sampling rate

作　　者：刘明翰 李春光[1] 赵勇健 王馨莹 王建伟 闫伟 LIU Ming-han;LI Chun-guang;ZHAO Yong-jian;WANG Xin-ying;WANG Jian-wei;YAN Wei(School of Mechanical and Electric Engineering,Soochow University,Suzhou 215131,China)

机构地区：[1]苏州大学机电工程学院,江苏苏州215131

出　　处：《激光与红外》2024年第10期1607-1612,共6页Laser & Infrared

基　　金：国家自然科学基金面上项目(No.62073228)资助。

摘　　要：为解决目前在国内外便携式近红外光谱成像系统(fNIRS)检测设备便携性差与采样率低的问题。提出了基于FPGA的近红外光谱成像系统调制解调方法。首先,基于FPGA实现光源驱动信号的“频分-时分复用”调制,单光源多波长之间进行频分,多光源之间进行时分,提高采样频率(频分)的同时兼顾系统体积(时分)大小;其次,基于FPGA实现探测信号的嵌入式数字解调与数字滤波,以便于直接基于嵌入式系统解算血氧信号并进行嵌入式应用。相比于当前的便携式脑血氧采集设备,基于FPGA实现嵌入式近红外光谱成像系统的设计与开发,提高采样率的同时,降低对FPGA的要求,减小体积增加便携性,基于FPGA的信号解调为实现嵌入式应用奠定重要基础,有望适用于更多的应用场景。In order to solve the current problem of poor portability and low sampling rate of wearable functional nearinfrared spectroscopy(fNIRS)detection equipment at home and abroad,a modulation and demodulation method of fNIRS based on FPGA is proposed in this paper.Firstly,the"frequency division-time division multiplexing"modulation of the light source driving signal is realized based on FPGA,and the frequency division is carried out between multiple wavelengths of a single light source,and the time division is carried out between multiple light sources,so as to improve the sampling frequency(frequency division)while taking into account the size of the system volume(time division).Secondly,the embedded digital demodulation and digital filtering of the detection signal is realized based on FPGA,so as to facilitate the interpretation of the blood oxygen signal and embedded application directly based on the embedded system.Compared with the current portable cerebral oximetry acquisition equipment,the design and development of FPGA-based embedded near-infrared spectroscopic imaging system improves the sampling rate,decreases the requirements for FPGAs,and reduces the size to increase portability.PGA-based signal demodulation lays an important foundation for the implementation of embedded applications and is expected to be suitable for more application scenarios.

关 键 词：近红外脑功能成像 高采样率 调制解调 嵌入式 

分 类 号：TN247[电子电信—物理电子学] TP391.41[自动化与计算机技术—计算机应用技术]