Research on the heat treatment process of intravascular nitinol stents

Abstract

Abstract With the aging of China’s population and changes in dietary structure, the incidence of peripheral arterial disease (PAD) is increasing year by year, and the number of PADs requiring intervention is increasing. Atherosclerosis, inflammation, trauma or injury, structural abnormalities of ligaments or muscles, or exposure to radiation are common causes of PAD. Minimally invasive treatment is an effective method to treat PAD, and nitinol alloy vascular stent has become an effective and safe minimally invasive interventional treatment method because of its shape memory effect, super elasticity, and excellent biocompatibility. This topic mainly studies the preparation of nitinol stents through finite element analysis simulation and heat treatment shaping. The stents are analyzed by optical microscope, DSC, Tensile Testing Machine, and Radial Force Tester. The specific research results are as follows: through finite element analysis, the shaping process parameters of the stent are determined. When the diameter of the stent is expanded to 5 mm in three steps, as the heating temperature increases from 500°C to 540°C, the color of the stent surface changes from blue to yellow, the temperature of the stent Af decreases, the radial support force and the stress of the upper and lower yield plateaus of the stent increase.