Strongly Coupled Fluid-Structure Interaction Cardiovascular Analysis with the Effect of Peripheral Network

Abstract

    Blood vessels are able to expand in order to let more blood .ow through them, as well as contract to help control the .ow of blood. Fluid-Structure Interaction (FSI) modeling simulates this process of expansion and contraction for more accurate results. The results of two analyses, namely the Fluid and FSI, are presented to compare a difference between the rigid and deformable walls, respectively. In the FSI analysis, strong coupling method (direct method) is used to solve the fundamental descretized equations to satisfy the geometrical compatibility and the equilibrium conditions on the interface between the .uid, representing the blood .ow, and the hyper-elastic structure, representing the vascular tissue. A high order Mooney-Rivlin material is used to model the vascular tissue. Automatic mesh update method is adjusting the .uid mesh under the defor-mation of the structure domain along the time. Peripheral vessels network is applied as out.ow boundary condition to the 3D Fluid and FSI simulations. The peripheral network is modeled as a binary symmetric tree attached to the outlet(s) of the 3D model. The small arteries are modeled us-ing 1D scheme, while the arterioles and capilaries are modeled using the structure tree impedance (STI) model. The coupling of the 3D Fluid-Structure .nite element model and the multi-scale model (1D -0D) facilitates the use of more realistic boundary conditions leading to more accurate information on the hemodynamic factors, e.g. wall shear stress (WSS). As, for example, low den-sity lipoprotein tends to deposit in the areas of blood vessels with low WSS. The degeneration of blood vessel walls is often initiated by hemodynamic forces, thus it is valuable to obtain the infor-mation on these factors for accurate prevention and prognosis of diseases such as atherosclerosis or middle cerebral aneurysm. [This abstract is not included in the PDF]