Application of the topological optimization technique to the stents cells design for angioplasty

Abstract

Restoring the internal lumen of arteries by employing an expandable mesh (stent) of metallic or polymeric material, known as angioplasty, is one of the most common procedure for treatment of the obstructive cardiovascular diseases. The stent for angioplasty have been extensively used in the treatment of the cardiovascular diseases. They should be flexible during the implant procedure and stiff when implanted into the blood vessel. These design criteria depend on the material, geometry and the technology used in the stents manufacturing. The objective of this work is to provide the optimized geometry of a stainless steel stent by means of the topological optimization technique. The general idea of this methodology is to simulate the implant process of a stent using the finite elements method, extract the sensitivities of its flexibility and stiffness and update its material distribution or topology in an iterative procedure. The algorithm for the numerical computation of the stent material distribution is based on the heuristics and in the Lagrangian of the optimization problem. The results show that the stent optimal topologies provided by this methodology have some advantages when compared with the traditional geometries of commercial stents. Copyright © 2008 by ABCM.