摘要
近红外扩散相关光谱(DCS)是一种先进的无创检测组织深层血流流速变化的动态光散射技术。为了解决光子相关器价格昂贵、灵活性差、应用局限、计算效率低的问题,采用将光子相关器软件化的方法,设计了一种近红外扩散相关谱检测系统。该系统以单纵模长相干激光器作为光源,采用单光子探测器探测散射光信号,用数字信号采集模块采集高速数字信号,并对数字脉冲信号进行计数,基于软件完成了对动态散射光斑光强归一化自相关的计算。结果表明,该系统计算出生物样品波动漫反射信号的时间平均强度自相关函数符合理论,验证了系统检测功能的可靠性;在客观评价指标方面,可成功区分不同的生物样品,并且能够分别体积分数差为1%的同种生物样品。该系统可以实时监测生物样品整体的光学特性和动态特性,具有体积小、成本低、灵活性好、可拓展性强的特点,为轻量化DCS检测系统的发展提供了一种新的解决方案。
Near-infrared diffusion correlation spectroscopy(DCS)is a relatively new method widely used for blood flow detection because deep biological tissues can be penetrated by near-infrared light,which has a low absorption coefficient and strong penetrating ability.The DCS technique differed from traditional biological sample detection techniques in that it used the time-averaged intensity autocorrelation function of fluctuating diffuse reflectance signals to detect blood flow within tissues,which could achieve non-destructive and continuous quantitative detection of biological samples.In response to the problems of low computational efficiency,high system price,cumbersome operation and application limitations of the current DCS detection system by hardware technology for scattered spot attenuation calculation,a near-infrared diffusion correlation spectrum detection system based on software was proposed and designed.Considering the light source requirement for correlation,a single longitudinal mode laser was used as the light source for this system,a single photon detector was used to detect the scattered light signal,and the signal was transmitted by the digital signal acquisition module,and the calculation of normalized autocorrelation for dynamic scattered light spot intensity was performed by the software.The experimental results show that the time-averaged intensity autocorrelation function of the fluctuating diffuse reflectance signals obtained from the detection of biological samples by the system is in accordance with the theory,which verifies the reliability of the detection function of the system;in terms of objective evaluation indexes,the system successfully discriminates between different biological samples and is able to separate biological samples of the same species with a difference in volume fraction of 1%.The system can monitor the overall optical and dynamic characteristics of biological samples in real-time and is characterized by small size,low cost,good flexibility,and strong expandability,which provides a new solution for the development of a lightweight DCS detection system.
作者
朱丽颖
刘玉红
程其娈
谭佐军
ZHU Liying;LIU Yuhong;CHENG Qiluan;TAN Zuojun(School of Engineering,Huazhong Agricultural University,Wuhan 430070,China;Institute of Applied Physics,Huazhong Agricultural University,Wuhan 430070,China)
出处
《激光技术》
CAS
CSCD
北大核心
2024年第4期578-583,共6页
Laser Technology
基金
国家自然科学基金资助项目(61605053)
中央高校基本科研业务费专项基金资助项目(2662023LXPY006)。
关键词
生物光学
近红外扩散相关光谱
光强归一化自相关
散射光斑
biomedical optics
near-infrared diffusion correlation spectrum
normalized autocorrelation of light intensity
diffuse optical spot
