Invesitigation Of Hemodynamics Of Stented Cranial And Carotid Artery: Computational Fluid Dynamics And PIV Measurements

The influences of implanted stent on the hemodynamic characteristic of the intracranial artery were studied in the present research. Computational Fluid Dynamics(CFD) and Particle Image Velocimetry(PIV) were used to accomplish this project which has drawn many attentions in medical science and engineering. The Multiphase Flow model, exactly the dual- Euler model, was chose in CFD to simulation the characteristic of the blood and the Refractive index Matching job was done in the PIV experiments.The main research orientations were as follows:1) Hemodynamics simulation of Cranial Artery Stenosis(CAS) with Stented:In the study of carotid angioplasty treatment using stenting, the normal artery model, the stenosis 80% artery model, the stented 90% and stented 110% artery model were constructed and simulated individually. To predict the effect of stented expansion and possibility of restenosis, emphasis is on the hemodynamic index such as velocity, impact, wall pressure, wall shear stress, particle retention time and so on. The patient-specific cases with unstented and stented models individually were simulated to study the clinical effect of stent and predict the possibility of the postoperative restenosis at this expansion ratio.2) Hemodynamics simulation of Intracranial Aneurysm(IA) with Stented:The feasibility of applying low porosity stent to the intracranial aneurysm was studied in this part. The effects of stent implantation with different porosity(80%, 70%, 60%) or different cross section shape(circle and square) on the hemodynamics index were examined combining with clinical experience and results in this part. Also the patient-specific cases with unstented and stented models individually were simulated to study the clinical effect of stent and predict and predict the possibility of the postoperative restenosis.3) PIV measurements:The sidewall aneurysm model(simplified model case) andthe intracranial aneurysm model(patient-specific model case) were chose as the experiment subjects to accomplish the PIV experiments. The reverse engineering technology and 3 D printing rapid prototyping technology were used to establish the three-dimensional transparent optical experimental model. To eliminate the optical distortion of complex flow channel, the refractive index was compensated using the Glycerol aqueous solution. The PIV results agree well with the CFD conclusions.The formation of arterial embolization and the effect of interventional therapy were closely related to hemodynamics, abnormal hemodynamic factors such as blood flow velocity, wall shear stress and pressure distribution could provide environment conditions for the deposition of particles in the blood. Because of the so many similarities between the hemodynamic stud y and the traditional fluid mechanics research, this paper used the professional knowledge, research methods and key technologies of power engineering and engineering thermal physics subject applied in the ministry of cranial artery to rich the research methods and channels of artery disease pathogenesis and the development trend. The conclusions will play a positive role in promoting the future of the clinical medicine research and will also become the indispensable supplementary means in clinical treatment.