http://orbilu.uni.lu/handle/10993/15809 http://orbilu.uni.lu/bitstream/10993/15809/1/media2013.pdf
http://orbilu.uni.lu/bitstream/10993/15809/3/miccai2013.wmv (MOVIE)
This paper presents a numerical method for interactive (real-time)
simulations, which considerably improves the accuracy of the response of
heterogeneous soft-tissue models undergoing contact, cutting and other
topological changes. We provide an integrated methodology able to deal
both with the ill-conditioning issues associated with material
heterogeneities, contact boundary conditions which are one of the main
sources of inaccuracies, and cutting which is one of the most
challenging issues in interactive simulations. Our approach is based on
an implicit time integration of a non-linear finite element model. To
enable real-time computations, we propose a new preconditioning
technique, based on an asynchronous update at low frequency. The
preconditioner is not only used to improve the computation of the
deformation of the tissues, but also to simulate the contact response of
homogeneous and heterogeneous bodies with the same accuracy. We also
address the problem of cutting the heterogeneous structures and propose a
method to update the preconditioner according to the topological
modifications. Finally, we apply our approach to three challenging
demonstrators: (i) a simulation of cataract surgery (ii) a simulation of
laparoscopic hepatectomy (iii) a brain tumor surgery.