A hybrid approach to determining cornea mechanical properties in vivo using a combination of nano-indentation and inverse nite element analysis

A hybrid approach to determining cornea mechanical properties in vivo using a combination of nano-indentation and inverse nite element analysis This item was submitted to Loughborough University's Institutional Repository by the/an author. A hybrid approach to determining cornea mechanical properties in vivo using a combination of nano-indentation and inverse nite element analysis. A hybrid approach to determining cornea mechanical properties in vivo using a combination of nano-indentation and inverse finite element analysis Abstract An analysis of the material properties of porcine corneas has been performed. A simple stress relaxation test was performed to determine the viscoelastic properties and a rheological model was built based on the Generalized Maxwell (GM) approach. A validation experiment using nano-indentation showed that an isotropic GM model was insufficient for describing the corneal material behaviour when exposed to a complex stress state. A new technique was proposed for determining the properties, using a combination of nano-indentation experiment, an isotropic and orthotropic GM model and inverse finite element method. The good agreement using this method suggests that this is a promising technique for measuring material properties in vivo and further work should focus on the reliability of the approach in practice. Journal of the Mechanical Behavior of Biomedical Materials 3 Graphical abstract Highlights 1-A new technique was proposed for determining the properties, using a combination of nano-indentation, an isotropic and orthotropic GM model and inverse finite element method 2-This approach enables determination of all the viscoelastic parameters for a cornea 3-To investigate the performance of the inverse method, the recovered parameters were checked against the fitted parameters from the stress relaxation experiment.