On inverse analysis and robustness evaluation for biological structure behaviour in FE simulation. Application to the liver

To prevent abdominal organs traumas, the definition of efficient safety devices should be based on a detailed knowledge of injury mechanisms and related injury criteria. In this sense, FE simulation coupled to experiment could be a valuable tool to provide a better understanding of internal organs behaviour under crash conditions. This work proposes a methodology based on inverse analysis which combines exploration process optimisation and robustness study to obtain mechanical behaviour of the complex structure of the liver through FE simulation. The liver characterisation was build on Mooney Rivlin hyperelastic behaviour law considering whole liver structure under uniform quasi-static compression. With the global method used, the model fits experimental data. The variability induced by modelling parameters is quantified within a reasonable time. Liver compression, FE simulation, inverse analysis, robustness analysis

Immediate post-operative procedure for identification of the rheological parameters of biological soft tissue

International audienceComputer simulations of minimal invasive procedures have been developed for surgery planning or training or for the evaluation of surgical procedure. In order to perform realistic and precise simulations of surgery on soft tissue, one key step consists in introducing accurate tissue-specific mechanical parameters. The goal of this work was to transfer an indentation procedure from the laboratory to the operating room using a new portable indentation device. The numerical simulations with 3D finite element software of the experiments allowed us to identify the characteristic rheological properties which minimize the gap between computed end measured physical quantities. The next step will be to extend this procedure to pathologic uterus and to other solid organs