Evaluation of Hyperelastic Constitutive Models Applied to Airway Stents Made by a 3D Printer

The present work aims to make a proof of concept comparing mechanical tests in a commercial model of airway stent (HCPA-1) versus experimental and virtual simulation mechanical tests using finite elements in a dimensionally similar stent made by a 3D printer in flexible non-biocompatible material. The material of the 3D printed stent was hyperelastically characterized from experimental mechanical tests on samples that allowed calculating the constitutive constants for the hyperelastic models. Virtual simulations of mechanical tests using finite element analysis in the ANSYS software with the available hyperelastic models were compared with the experimental tests, obtaining the precision of the hyperelastic models in the material used to print the stent. A cough-like mechanical test was performed experimentally on HCPA-1 and 3D printed stents simulating a critical condition of use. The results were compared with a virtual simulation using the hyperelastic models obtaining precision that varied from 2.5 to 280% depending on the hyperelastic model used. The work shows that it is possible to obtain virtually the mechanical response of an airway stent using finite elements. Making it possible to minimize the time and financial investment needed to evaluate the research and development of new materials, geometries or customized models based on medical images using the 3D printing technique. Flexible and biocompatible materials for the 3D printer should emerge in the future. Allowing 3D printing of implantable airway stents in patients.