OPTIMIZATION OF PLLA STENT TO ACHIEVE HIGH FLEXIBILITY USING RESPONSE SURFACE METHODOLOGY

Abstract

Stent flexibility is essential for navigating stent placement through complex cardiovascular anatomy. Flexible stents can minimize the impact of external forces on the arterial wall, which can lead to more stable heart beat. Modern stents often use PLLA material, which have biodegradable properties and are compatible with the arterial healing process. This study investigates the optimization of pure PLLA stent to achieve high flexibility. The analysis was conducted by exploring material properties, including bending moment and thickness, and their effects on stent performance using the Finite Element Method (FEM) and Response Surface Methodology (RSM). Optimization using RSM resulted in the crimped condition of the Pure PLLA stent, with a bending moment of 0.0044 N.mm, a thickness of 87.0002 μm, a curvature index of 0.0261 rad/mm and a von Mises stress of 16.6283 MPa. In the expanded condition of the Pure PLLA stent, with a bending moment of 0.0120 N.mm, a thickness of 75.8579 μm, a curvature index of 0.0895 rad/mm and a von Mises stress of 46.0882 MPa. These results demonstrate the capability of RSM in refining the design and achieving high curvature index as a flexibility.