Validation of an ovine lung parenchyma material model with pressures representing the breathing cycle for high-velocity impacts

Abstract

Lung injury risk from high-velocity blunt impacts is thought to depend on lung pressure. Risk is typically assessed with finite element models (FEMs), but models do not typically account for lung pressure, nor do they account for lung viscoelasticity. The objective of this study is to translate and then validate a set of lung material models that consider both tissue viscoelasticity and pressure in silico. This was completed using one set of quasi-static simulations for translation and one set of dynamic simulations for validation to compare to experimental forces, where CORA was utilized. Digital image correlation (DIC) data of strain and displacement magnitude from the quasi-static experiments were also used to ensure proper material model translation. Three simulations were run for each loading case, where the only difference was the lung material properties to account for pressure (0, 4, and 10 cmH₂O). The force–time responses for both simulations showed good agreement with experimental data with a range of 0.77–0.93 CORA scores for the dynamic loading, and a range of 0.84–0.97 CORA scores for the quasi-static simulations, with all simulations falling under “good” or “excellent” categories. The DIC-equivalent data for the quasi-static simulations were determined to be dependent on mesh size. Overall, the quasi-static simulations showed the material was translated into LS-Dyna well, and each of the lung material models were able to reproduce the global force–time responses well in the dynamic simulation set.