TiNi形状記憶合金ステントの疲労特性

抄録

TiNi shape memory alloys (SMAs) have higher fatigue strength, corrosion resistance, and biocompatibility than those of the other series of SMAs, and are developed much applied products in the medical field. One notable example in the medical field is the use of self-expanding stents. Stents are usually inserted into narrowed blood vessels and work by dilating the vessel from the inside to ensure blood flow. The implanted stent must support blood vessels under repeated loading due to pulsation, etc., and thus must have both of enough fatigue strength and high dilatation force. The objective of this study is to investigate the mechanical properties of TiNi SMA stents and propose a manufacturing process that can achieve both excellent fatigue strength and high vasodilatation force. In this presentation, we have developed a 3D model of the stent using this manufacturing process, and we have employed finite element analysis to investigate the local deformation behavior under radial uniaxial compression. The analysis results demonstrate the capability to accurately reproduce the complex deformation behavior of the stents.