Simulated inflation of a vascular stent using 3-dimensional nonlinear fea contact analysis

The article discuses simulating the in-vivo placement of a barrel type vascular stent in an artery. The barrel type stent was machined from thin walled stainless steel tubing by EDM methods. In the FEA model the full 3-dimensional contact at the interfaces between separate components, nonlinear material properties, large displacements, and follower force techniques for pressure loading were included. A simulated surgical pressurization schedule was used to inflate the catheter balloon, expanding the stent radially. In this expansion, both the balloon and the stent impact upon the arterial wall. Incremental de-pressurization of the balloon allows the stent to relax and be compressed radially by the artery wall until a nominal equilibrium condition is reached.