A patient-specific aortic valve model based on moving resistive immersed surfaces
Author(s):
Fedele, Marco
Title:
A patient-specific aortic valve model based on moving resistive immersed surfaces
Date:
Monday 9th February 2015
Advisor:
Quarteroni, A.
Advisor II:
Faggiano, E.
Co-advisor:
Laadhari, A.
Abstract:
The study of hemodynamics in the ascending aorta through computational
uid dynamics simulations is a subject of large interest in medical research
for its application in the study of dierent diseases.
The aim of this work is to enrich the numerical simulation with a moving
aortic valve model. Closed and open valve surfaces as well as the lumen
aorta are reconstructed directly from medical images using a new specic
algorithm, allowing a patient-specic simulation.
The valve surface is inserted in the classic Navier-Stokes equations adding
a dissipative term with a resistance that can be interpreted as a penalization
parameter enforcing the condition of null velocity on it. Furthermore,
we considered also the movement of the valve between its closed and open
position using a reduced zero-dimensional model to compute the valvular
angle governed by pressure and ow-rate values in the left ventricle and in
the aorta.
We describe the valve surface as the zero level of a level set function de-
ned analytically. From a numerical point of view, this strategy avoids
the problem of having bi-dimensional nite elements immersed in the threedimensional
domain consistent with the valve surface. Moreover, in this way
the mesh does not have to change at each time step with the movement of
the valve avoiding remeshing and high-computational costs.
This model can help in a better understanding of the hemodynamics in the
ascending aorta, hence it can be used to study aortic and valvular diseases
or valvular prosthesis. Furthermore it can be easily extended to the other
cardiac valves, helping in the building of a complete heart-integration model.