Effect of link design of thin cardiovascular stent to its flexibility

Abstract

Until recently, stent has been used effectively to open a cardiovascular blockage due to the plaque. Various designs of stent are available commercially in the marketplace. Thus, it was difficult to select the suitable stent that meets to the varying needs of the patient beyond the material, such as flexibility, inflated diameter, and radial strength. The present study would focus on finding the effect of link design to its flexibility, while the strut design was remained and the material was the same. The study was carried out by finite element modeling and software ABAQUS 6.13 was employed to perform the simulation. The metal alloy of Cobalt has been selected to be material of the stent model. A thin stent model consists of a pair of the strut which was connected by three links (L1, L2, L3) with a thickness of 60μm and 80μm frame wide. The model has a size of 1.237mm in outer diameter and 2mm long. The flexibility was expressed by the curvature index as the ratio of bending angle to stent length. The flexibility was performed at the bending moment concerning x-axis (Mxx) and y-axis (Myy). Results indicated that link design L1 performed the highest flexibility compared to other link designs which was indicated by the highest curvature index at the same value of bending moment (Mxx and Myy).