Influence de la géométrie et des propriétés mécaniques sur la simulation Eléments Finis du système pelvien.
Résumé
The woman pelvic system is an anatomical area involving multiple organs, muscles, ligaments, and fasciae where different pathologies may occur. Here we are most interested in abnormal mobility, often caused by complex and not fully understood mechanisms. Mathematical modelling and computer simulation using the Finite Element (FE) method are the tools helping to better understand the pathological mobility, but of course patient-specific models are required to make contribution to patient care. These models require a good representation of the pelvic system geometry, information on the material properties, boundary conditions and loading. In this contribution we focus on the relative influence of the inaccuracies in geometry description, derived from medical images, and of uncertainty of patient-specific material properties of tissues. We conducted a comparative study using several constitutive behavior laws, different material coefficients and variations in geometry description resulting from the imprecision of clinical imaging and image analysis. We find that it is the geometry that has the dominant effect on the pelvic organ mobility simulation results. Provided that proper finite deformation non-linear Finite Element solution procedures are used, the influence of the functional form of the constitutive law is for practical purposes negligible and the influence of the stress parameter in the constitutive law is relatively small. These last findings confirm similar results from the fields of modelling neurosurgery and abdominal aortic aneurysms.
Domaines
Mécanique [physics]
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