Research On Method And Application Of In Vivo Blood Flow Detection Based On Laser Speckle Imaging

Microcirculation transports oxygen and nutrients for biological tissues,and at the same time takes away metabolic wastes,which is the basis for the normal operation of biological activities.As one of the important parameters of life activities,blood flow is an important indicator to measure the functional state of organisms.In recent years,laser speckle imaging(LSI)technology has developed rapidly.Because of its advantages of non-invasive detection,wide-field imaging,and high spatial and temporal resolution,it is widely used in the detection of microcirculation blood flow in biological tissues.On the basis of LSI system,this paper explores the principle of eigen-decomposition of speckle signals,studies the quantitative analysis method of flow velocity based on eigen-decomposition,designs a functional software control system,and carries out dynamic detection experiments of mouse ear microcirculation in vivo with LSI technology.The results show that the method based on eigen-decomposition can achieve the rapid and high-resolution reconstruction of blood flow image,and the built LSI system can effectively detect the dynamic changes of microcirculation.On the basis of LSI system,a software control system is designed.The software mainly includes functions such as camera control,image acquisition and image reconstruction.Its biggest advantage is that it can synchronize the process of image acquisition and image reconstruction,that is,it can complete the rapid reconstruction of blood flow image by eigen-decomposition method at the same time of image acquisition,so as to realize the dynamic detection of blood flow in vivo.The LSI method and flow velocity analysis method based on the eigen-decomposition principle are studied,and the influence of three parameters is analyzed,that is exposure time,sampling frame number and vector selection.The performance of the reconstruction algorithm is optimized,and the spatial resolution and the imaging speed of the reconstructed blood flow image are improved,which realize rapid blood flow detection.The velocity characteristics and frequency characteristics of different eigenvectors are studied to verify the feasibility of the method.Using the researched system and method,the dynamic imaging experiments of mouse microcirculation in vivo based on LSI was carried out,which verified the ability of the system in vivo imaging and quantitative measurement of flow velocity.The system is used to detect changes of blood flow and microvascular under the condition of temperature and current,so that the microcirculation changes under two kinds of stimulation are obtained,which provides a reference for the application of in vivo microcirculation function detection based on LSI.