Effect of Friction and Material Compressibility on Deformable Modeling of Human Lung

A three dimensional finite element model has been developed to investigate the sliding mechanics and compressibility of human lungs of seven lung cancer patients. The model consists of both lungs, tumor, and chest wall. The interaction between lungs and chest cavities is modeled using surface-based contact with coefficient of friction of 0, 0.1 and 0.2. Experimentally measured hyperelastic material properties of the lungs are applied in the model with different degrees of compressibility using Poisson’s ratio (

ν

) of 0.35, 0.4, 0.45 and 0.499. The analytical results are compared to actual measurements of the bifurcation of the vessels and bronchi in the lungs and tissues. The least absolute average error of 0.21(±0.04) cm is reached when frictionless contact surfaces with hyperelastic material and Poisson’s ratio of 0.35 and 0.4 are applied. The error slightly changes in contact models as the coefficient of friction and Poisson’s ratio increases. However, Poisson’s ratio has more effect in models without contact surfaces where the average error changes from 0.33(±0.11) cm to 0.26(±0.07) cm as the Poisson’s ratio increased from 0.35 to 0.499.