PSU Mark
Eberly College of Science Mathematics Department

Meeting Details

For more information about this meeting, contact Victor Nistor.

Title:A multi-mechanism constitutive model for cerebral arterial wall: application to cerebral aneurysm
Seminar:CCMA Luncheon Seminar
Speaker:Mariarita de Luca, SISSA -International School for Advanced Studies
Abstract:
A cerebral aneurysm is a localized bulge of the arterial wall, resulting from an initial dilatation. Usually it appears on the side or at a bifurcation of a cerebral artery. Unfortunately it is asymptomatic until rupture, and this sudden phenomenon causes a severe cerebral hemorrhage. Advanced imaging techniques are nowadays able to provide very helpful tools to support medical doctors in the treatment of cerebral aneurysms. With that future perspective, this preliminary work aims to develop a numerical tool for a non-linear multi-mechanism model, that is suitable to represent the mechanical behavior of the healthy cerebral arterial wall and early stage cerebral aneurysm formation. The core of the multi-mechanism model is to consider the arterial wall made up two mechanisms, related to its two main passive constituents: elastin and collagen. Histological studies show that the early stage aneurysm formation is associated with the disruption of elastin, that is found fragmented in the arterial wall. From experimental observations, the elastin actively contributes to load bearing even at low deformation level, while the collagen network is in a crimped state in its stress free con?guration. For larger deformations, the collagen network stretches out and starts to contribute to the mechanical behavior of the arterial wall. The strain energy of the model is additively composed by two terms, one related to the ?rst mechanism and the other related to the second one. The collagen recruitment and the elastin rupture happen when some threshold deformations are reached. The numerical model has been validated on test cases for which an analytical solution is available, showing the expected behavior. In the case of a cylindrical geometry representing a segment of a cerebral artery, we show that the computational multi-mechanism model is able to capture the non-linear and inelastic behavior of the arterial wall, and the early stage aneurysm formation.

Room Reservation Information

Room Number:MB114
Date:12 / 09 / 2011
Time:12:15pm - 01:30pm