title: Liver tissue characterization from uniaxial stress-strain data using probabilistic and inverse finite element methods.
abstract: Biological soft tissue is highly inhomogeneous with scattered stress-strain curves. Assuming that the instantaneous strain at a specific stress varies according to a normal distribution, a nondeterministic approach is proposed to model the scattered stress-strain relationship of the tissue samples under compression. Material parameters of the liver tissue modeled using Mooney-Rivlin hyperelastic constitutive equation were represented by a statistical function with normal distribution. Mean and standard deviation of the material parameters were determined using inverse finite element method and inverse mean-value first-order second-moment (IMVFOSM) method respectively. This method was verified using computer simulation based on direct Monte-Carlo (MC) method. The simulated cumulative distribution function (CDF) corresponded well with that of the experimental stress-strain data. The resultant nondeterministic material parameters were able to model the stress-strain curves from other separately conducted liver tissue compression tests. Stress-strain data from these new tests could be predicted using the nondeterministic material parameters.
authors: Department of Mechanical Engineering, National University of Singapore, Singapore. g0800248@nus.edu.sg
authors: Y B
authors: YB
authors: Fu
authors: C K
authors: CK
authors: Chui
authors: C L
authors: CL
authors: Teo
mesh_terms: D000818:Animals; D019245:Compressive Strength / Q000502:physiology; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D055119:Elastic Modulus / Q000502:physiology; D020342:Finite Element Analysis; D008099:Liver / Q000502:physiology*; D008954:Models, Biological; D015233:Models, Statistical; D013314:Stress, Mechanical; D013552:Swine; D013718:Tensile Strength / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology*