Structural Design And Mechanical Property Analysis Of Self-expanding NiTinol Stent

The stent used in traditional interventional therapy is a balloon-expanded stent.Due to plastic deformation at the end of the expansion,the stent will severely damage the physiological pulsation performance of the blood vessel after being implanted into the blood vessel,and the elastic recovery phenomenon easily occurs,too.However,the medical self-expanding NiTinol stents rely on the superelasticity and temperature characteristics of the nickel-titanium alloy to realize self-expansion of large deformation,and then support the diseased blood vessels.Compared with conventional balloon-expanded stents,medical self-expanding Nitinol stents have become a hot issue in medical interventional fields and academic field for their wide range of applicable conditions,small damage to the diseased lumens,high strength,and good biocompatibility.Because the medical self-expanding NiTinol stents involve large deformation and large strain during the deformation process,and their working environment is complex,which makes it difficult to simulate the medical self-expanding NiTinol stents with experiments,as well as to design and analyze the mechanical properties of stents.In this paper,three-dimensional solid modeling software Pro/Engeering and finite element software ABAQUS6.14 were used to perform the finite element simulation analysis on the medical self-expanding NiTinol stents,then a new W-shaped structure of self-expanding stent has been designed,and its main mechanical properties were analyzed.The main work is as follows:First,the finite element method was used to compare the accuracy of the analysis of the radial compression resistance of V-shaped medical self-expanding Nitinol stents by using two different compression methods,one is a curved discrete rigid bodies and the other is a variable diameter thin-walled cylinder.The thin-walled cylinder compression method proved to have a more accurate calculation result and a faster calculation speed.Based on the research conclusions of V-shaped medical self-expanding Nitinol stents,a new W-shaped structure medical self-expanding Nitinol stent for femoral artery stenosis was designed,and the compression resistance of the two stents was compared and analyzed.,and then the impact of the connection arc diameter and structure ratio of the W-Stent on its compression resistance was discussed.