The Design And Preparation Of Textile-based Branch Artificial Blood Vessel

Endovascular Graft Exclusion (EVGE) is an effect technology which is minimally invasive and safe to treat many kinds of aorta expansion diseases, especially for the patient who is in risk and not suit for surgery. However, for therapies of the expansive aorta with branches, the technology of EVGE is difficult to keep balance between the isolation of the diseased artery and the supply of the blood to the distal organs at the branch arteries in the mean time. On the basis of this problems, this study first presented a new branch of artificial blood vessel model, namely the automatic release branch artificial vascular. It can be implanted into the bodies with artery together under the action of the blood pressure and the shape memory function of the artificial branch artery the central region of branch graft can broke into the branch artery, meanwhile reduce the difficulty of surgery.First, in this study, it is assumed that the aorta is a cylindrical shape. At the same time the axis of the branch graft and aortic vascular axis is vertical and blood is a complex fluid that can be considered as an incompressible Newtonian fluid. Therefore, the Bernoulli equation can be used to acquire the structure parameter of the curved-shape branch vessel, which it can be regarded as reference standard to establishment geometric model in hemodynamics.Second, An curved-shape branch artery-blood coupling model was established, using the method of finite element and Fluid Solid Interface in Ansys CFX. Coupling calculation of structural and fluid analysis was realized with different materials, and then the velocity vector, the displacement and von mises stress distribution of pipe wall were obtained. Results show that the blood flow steady with curved-shape structure; the total mesh displacement of blood vessel is between dacron-made artificial blood vessel and polyurethane-made artificial blood vessel; the von mises stress at the distalend of branch vascular grafts is bigger.Then, based on the functional requirement of branch vascular graft, and the "shape memory" function, polyester, polyurethane was selected as materials in this paper. polyurethane vascular graft reinforced by elastic grid fabric with curved-shape structure was acquired through dipping-drain method.Finally, the biomechanics and the property of shape memory were tested. Test results shown that elastic grid fabric improve the biomechanical and elastic recover property.In brief, this research explored the materials and structures of the artificial blood vessel. According to the fundamental of fluid mechanics and the analysis results of the coupling calculation, this study had made two kinds of curved-shape branch vessel, and tested the biomechanics and elasticity recovery properties of the two samples. The research conclusion was helpful to the materials selection, structural design and manufacture of the artificial blood vessel materials.