| Title: | Image-based flow simulations applied to the blood circulation
and
to the respiration in normal and diseased conditions Application example: the saccular aneurism |
| Date: | October 21, 2005 (Friday) |
| Time: | 2:30 p.m. - 3:30 p.m. |
| Venue: | Room 121, 1/F, Ho Sin-hang Engineering Building, The Chinese University of Hong Kong, Shatin, N.T. |
| Speaker: | Dr. Marc Thiriet projet INRIA REO INRIA Rocquencourt Universite Pierre et Marie Curie Laboratoire Jacques-Louis Lions, Paris |
Saccular aneurisms illustrate usefulness and possible techniques of image-based modelling of flow in diseased vessels. Aneurism flow is investigated in order to estimate the rupture risk, assuming that the pressure is the major factor and that high-pressure zones are correlated to within-wall strong-stress concentrations. Computational flow is also aimed at providing additional arguments for the treatment strategy. Angiographies of aneurismal vessels of large and medium size are processed to provide three-dimensional reconstruction of the vessel region of interest. Different reconstruction techniques are used for a side- and a terminal aneurisms. Reconstruction techniques may lead to different geometries especially with poor input data. The associated facetisation is improved to get a computation-adapted surface triangulation, after a treatment of vessel ends and mesh adaptation. Once the volumic mesh is obtained, the pulsatile flow of an incompressible Newtonian blood is computed using in vivo non-invasive flowmetry and the finite element method. The stronger the blood impacts on the aneurismal wall the higher the pressure. The state of the aneurism neck, where a high-pressure zone can occur, and the location of the aneurism, with an easy access or not, give arguments for the choice between coiling and surgical clipping. Mesh size and 3D reconstruction procedure can affect the numerical results. Helpful qualitative data are provided rather than accurate quantitative results in the context of multimodelling.
BIOGRAPHY:
Marc Thiriet, graduated with an MD in 1978 from Paris VI university, received the Doctorat de 3e cycle in Biomechanics in 1981 from the Compiègne University of Technologie and the Habilitation à Diriger des Recherches in 1994 from the Physics Department of Paris VII University. He worked 10 years in the Lung Disease Department of Pontoise hospital. He is now head INRIA REO team, as well as coordinator of INRIA "ACE" Associate Team, and of ERCIM "IM2IM" working group. The REo team is bilocalised both at Rocquencourt Research Unit and Jacques-Louis Lions Laboratory (CNRS 7598, Paris VI University). He experimentally and numerically investigated flows in collapsible tubes, 3D, steady or periodic, flows of incompressible Newtonian or shear-thinning fluid in bends and branching sites. He is currently working in fluid biomechanics, either in simple models or in imaged-based domains of the circulatory and respiratory systems.
Enquiries: Miss Temmy So at tel 2609 8444
For more information, please refer to
http://www.cse.cuhk.edu.hk/seminar