Sensitivity of XXXX motion simulation accuracy to lung biomechanical modeling approaches and parameters.

@entity5 @entity1 @entity2
UNASSIGNED: Finite element analysis (FEA)-based biomechanical modeling can be used to predict lung respiratory motion. In this technique, elastic models and biomechanical parameters are two important factors that determine modeling accuracy. We systematically evaluated the effects of lung and @entity2 biomechanical modeling approaches and related parameters to improve the accuracy of motion simulation of @entity2 center of mass (TCM) displacements. Experiments were conducted with four-dimensional computed tomography (4D-CT). A Quasi-Newton FEA was performed to simulate lung and related @entity5 displacements between end-expiration (phase 50%) and other respiration phases (0%, 10%, 20%, 30%, and 40%). Both linear isotropic and non-linear hyperelastic materials, including the neo-Hookean compressible and uncoupled Mooney-Rivlin models, were used to create a finite element model (FEM) of lung and @entity5 . Lung surface displacement vector fields (SDVFs) were obtained by registering the 50% phase CT to other respiration phases, using the non-rigid demons registration algorithm. The obtained SDVFs were used as lung surface displacement boundary conditions in FEM. The sensitivity of TCM displacement to lung and @entity5 biomechanical parameters was assessed in eight @entity1 for all three models. @entity1 -specific optimal parameters were estimated by minimizing the TCM motion simulation errors between phase 50% and phase 0%. The uncoupled Mooney-Rivlin material model showed the highest TCM motion simulation accuracy. The average TCM motion simulation absolute errors for the Mooney-Rivlin material model along left-right, anterior-posterior, and superior-inferior directions were 0.80   mm, 0.86   mm, and 1.51   mm, respectively. The proposed strategy provides a reliable method to estimate @entity1 -specific biomechanical parameters in FEM for @entity2 motion simulation.
