近红外扩散相关光谱系统的研制OA北大核心CSTPCD

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.