The Modeling Of The Aortic Blood Vessel And The Numerical Simulation Of The Blood Flow Dynamics

Based on several groups of CT image data provided by the Affiliated Hospital of Inner Mongolia University for Nationalities,three-dimensional geometric model was reconstructed by using Medical Three-dimensional Reconstruction Software MIMICS 17.0,The processes include CT raw data processing,image sequence generation,hierarchical reconstruction of vascular model and printing of vascular solid model.In the process of using the blood vessel segmentation algorithm,we need to extract human vascular contour features by threshold method,process contour area by gray-scale separation method,and create a three-dimensional models with the real vessel by using the region growth method,the fuzzy boundary is manually selected.The three-dimensional structure models of aortic vessels in healthy people,aortic dissection and abdominal aortic aneurysms were selected,and we need to calculate these several groups of reconstructed aortic models by finite element method.To study and compare the difference of the blood flow condition in healthy aortic vessels and aortic vessels in patients with disease.To study the relationship between the occurrence and development of diseases and the hemodynamic characteristics of aortic vessels.To study the influence of hemodynamic factors on the occurrence and development of aortic vascular diseases.Comparing the numerical results of the healthy human aortic vascular structure model,it was found that:1 due to the abnormal shape of aortic arch,the hemodynamic environment was complex and easy to occur dissecting diseases.The swirl and turbulence phenomenon of blood flow in the medial vessel is the inducement of further dissection of aortic dissection.The low shear stress in the dissection area also leads to the deposition of blood cells and fat particles in the blood,which makes the blood vessel wall inelastic.2 The aorta grows abnormal bending and abnormal distortion while existing the secondary flow.The secondary flow with high speed and vortex will cause an unmitigated destruction on the vascular wall,also cause the formation of aneurysms and gradually increase the diameter of the aneurysms.At the same time,the high pressure concentration zone in the tumor will cause the wall of the vessel to become thinner,thus increasing the risk of rupture.Through the numerical calculation of hemodynamics of aortic dissection and abdominal aortic aneurysm disease,the important influence of abnormal deformation(bending,distorting,etc.)on the occurrence and development of aortic dissection and aneurysm was investigated.It is beneficial to the prevention and control of this kind ofdisease,and it also provides the guidance of hemodynamics theory for the clinical effective interventional therapy.