Analysis Of And Biomechanical Behavior For The Coronary Stent

The Percutaneous Transluminal Coronary Angioplasty (PTCA) has become a primary therapy of coronary heart disease in our country, as an important implanted device ,coronary stent , was often used in the PTCA. There were very strict requirements for not only the biocompatibility of the manufacture of the stent.In the whole word, the key technique of coronary stent design would remain the focus of attention. There were two kinds of coronary stent design——"S","{" in this paper, According to three main deformation precesses: which were the crimped mechanical behavior to the balloon, expansion behavior depending on inflating of balloon and resistance behavior to compressing happening while the balloon is retrieved. Build up the three-dimensional (3D) finite element emluational models of stents with 316L stainless steek L605CoCr and Nitinol were constructed by a 3D software UG and a finite element analysis (FEA) software ANSYS. The contents of designing the coronary stent include : simulating the expanding process and experiment verification,optimizing no-shortening coronary stents and simulating,flexibility and so on.According to the researches results, the expansion and flexibility of stent were associated with the materials and structure design. When the coronary stents made of the three materials were expanded on the same scale, the pressure to expand the CoCr stent was more than 316L and Nitinol; Compared with "S" stent, the "{" stent needed more pressure and rebound. The flexibility and stability of Nitinol was best, and the flexibility of "S" stent was better than "{" stent. Otherwise, the shortening of stent is not associated with the material but design, the shorten of "{" stent is less than "S" stent.Combined with the results of the expansion, flexibility and shortening behavior of stents, it was indicated that the stent with "S" form struts and Nitinol insured appropriate diameter, small shortening and good flexibility.The researches result of this paper supply designers to reliable data and reference for design of coronary stent and mechanical behavior.