Simulation of mechanical behavior of temperature-responsive braided stents made of shape memory polyurethanes.
Polymeric stents can be considered as an alternative to metallic stents thanks to their lessened incidence of restenosis and controlled deployment. The purpose of this study was to investigate the feasibility of developing a temperature-responsive braided stent using shape memory polyurethane (SMPU) through finite element analysis. It was assumed that braided stents were manufactured using SMPU fibers. The mechanical behavior of SMPU fibers was modeled using a constitutive equation describing their one-dimensional thermal-induced shape memory behavior. Then, the braided stents were analyzed to investigate their mechanical behavior using finite element analysis software, in which the constitutive equation was implemented through a user material subroutine. The diameter of the SMPU fibers and braiding angle were chosen as the design parameters and their values were adjusted to ensure that the mechanical properties of the braided polymer stents match those of metallic stents. Finally, the deployment process of the braided stents inside narrowed vessels was simulated, showing that the SMPU stents can be comfortably implanted while minimizing the overpressure onto the vessel walls, due to their thermo-responsive shape memory behavior.
Kim
Ju Hyun
JH
Intelligent Textile System Research Center, Department of Materials Science and Engineering, Seoul National University, 599 Gwanangno, Gwanak-gu, Seoul 151-742, Republic of Korea.
Kang
Tae Jin
TJ
Yu
Woong-Ryeol
WR
D003198:Computer Simulation; D017076:Computer-Aided Design; D055119:Elastic Modulus; D019544:Equipment Failure Analysis; D008956:Models, Chemical; D011140:Polyurethanes / Q000737:chemistry*; D011474:Prosthesis Design; D015607:Stents; D013314:Stress, Mechanical; D013696:Temperature; D013718:Tensile Strength
D011140:Polyurethanes