EVENTO
Modeling Issues of Fluid-structure Interaction in Computational Hemodynamics
Tipo de evento: Exame de Qualificação
This revision article presents the thesis proposal aiming at addressing the modeling of three-dimensional arterial blood flow and its effect on the arterial wall mechanical state when dealing with patient-specific geometries. The modeling of this problem is highly complex and several key aspects have to be taken into account. Such issues have been treated separately in the scientific community. Within this context the present research project has two main goals.The first objective is directed towards integrating most of these key issues in a modeling framework and analyzing scenarios of interest to gain insight about the interplay of the modeling ingredients. Particularly, the focus will be set on combining modeling techniques to take into account (i) the fact that image-based configurations are in a preloaded state, (ii) the complexity of the constitutive response of the arterial wall, (iii) the compliance of the arterial wall and its interaction with the blood flow, and (iv) the use of proper boundary conditions on the artificial interfaces between the aforementioned three-dimensional model and the rest of the cardiovascular system. To address the first topic, the mechanical preload problem will be formulated, solving the equilibrium equation when the spatial geometry is known (data extracted from medical images). For the second issue, finite strains regime and multi-layered transversely isotropic hyperelastic materials are considered to represent the mechanical behavior of the arterial wall. Finally, for the last points, iterative schemes are used accordingly to model both the fluid-structure interaction in the 3D geometry and the coupling between this detailed model and a dimensionally-reduced model of the rest of the cardiovascular system through 1D mathematical representations of the blood flow. Such integration is at the forefront of the field, and would imply an important advance in terms of understanding the role played by the different modeling hypotheses considered in this class of cardiovascular models.The second goal set for this research project is to develop a strategy capable of performing in-vivo characterization of residual stresses using information provided by dynamic medical images. The methodology proposed consists on formulating the characterization problem as an optimization problem to find the mentioned stresses and the unloaded configuration of our arterial segment given a set of images corresponding to different loading states, and to devise an minimization algorithm based on the sensitivities of a proper cost functional. It is important to highlight that this would be a substantial contribution to the field, provided that no in-vivo technique is available to perform such kind of inverse characterization.
Data Início: 10/12/2013 Hora: 10:00 Data Fim: 10/12/2013 Hora: 12:00
Local: LNCC - Laboratório Nacional de Computação Ciêntifica - Auditorio A
Aluno: Gonzalo Damián Ares - LABORATÓRIO NACIONAL DE COMPUTAÇÃO CIENTÍFICA - LNCC
Orientador: Pablo Javier Blanco - Laboratório Nacional de Computação Científica - LNCC
Participante Banca Examinadora: Abimael Fernando Dourado Loula - Laboratório Nacional de Computação Científica - LNCC Antônio André Novotny - LNCC - LNCC Gustavo Alberto Perla Menzala - LNCC/UFRJ - LNCC