Level set methods to build moving meshes for patient specific blood flow simulations

Abstract

Introduction The hemodynamic factor in the thoracic aorta is believed to play an important role in the initiation and the progress of endovascular injuries. Most reported studies are dealing with averaged physiological geometries and rigid arterial boundaries. However, for diseases such as the aortic dissection, the geometrical changes are very patient specific and the wall motions over the cardiac cycle influence the blood flow drastically. There is a need to generalize the patient specific studies where the actual inlet/outlet boundary conditions and wall motions are accounted for. In the most general approach, the geometrical changes during the cardiac cycle result from the coupled fluid-structure interaction problem. This path is very challenging because the density of blood and tissues are of the same order, the rheology of the vessels is far from well understood and because the actual answer depends on the interaction of the arteries with the surrounding organs. Another option is to study the response of the blood flow submitted to prescribed wall motions and geometry changes. In this study we propose a method to build patient specific geometric data and boundary conditions for unsteady CFD runs with variable meshes valid over the cardiac cycle.