Optical Vortex Motion Statistics Based Blood Coagulation Dynamic Evaluation

The normal coagulation process is the body's defense mechanism to maintain blood flow and prevent blood loss.Its abnormality can result from a variety of conditions including severe trauma,temperature imbalance,or surgery,and can cause coagulopathy including subcutaneous bleeding,atherosclerosis,and even be life-threatening.The coagulation mechanism is complex due to the interactions between platelets,red blood cells,and more than a dozen coagulation factors,as well as three different coagulation pathways,endogenous,exogenous,and common.The normal coagulation process depends on a delicate dynamic balance among the coagulation,anticoagulation,and fibrinolysis.Therefore,it is important to evaluate blood coagulation dynamics and obtain the full appearance of the coagulation process for the diagnosis,prevention,and treatment of related diseases.However,conventional coagulation tests(CCTs)cannot meet the requirements of evaluating the dynamic process of coagulation because they can only measure a certain time point or part of the process of coagulation or fibrinolysis,or certain products in the coagulation.To overcome the defects of CCTs,this dissertation proposes a new method based on the microrheological for the detection of the coagulation dynamic process and explores the accuracy and sensitivity of this method through a large number of experiments.In this dissertation,the mechanism of coagulation is introduced in detail.The development of coagulation detection in recent years is reviewed.The main problems in coagulation detection are pointed out.Then,the theory of laser speckle and the optical vortex is introduced in detail.The principle of the optical vortex method for coagulation evaluation is described.The Brownian motion of the scattering particles,which is determined by the viscoelasticity of the microenvironment,can cause the variation of laser speckle with time.Thus,a technique was developed to reflect the dynamic changes in viscoelasticity of blood in the coagulation by depicting the mean square displacement per unit time of the optical vortex as a function of time,achieving the evaluation of the whole process of blood coagulation dynamics.The coagulation parameters including reaction time,activated clotting time,maximum viscoelastic modulus of the thrombus,which can reflect the dynamic process of coagulation,were obtained by feature extraction of coagulation curves.The accuracy of these parameters in reflecting the dynamic process of coagulation was verified by correlation analysis of these parameters with corresponding clinical indicators,such as those measured by thromboelastography.Two-dimensional images of the viscoelasticity of blood were obtained by two-dimensional scanning during coagulation,which is potential to be a new approach to research the spatial variation of blood viscoelasticity during coagulation.