| Speaker: | Adelia Sequeira, Department of Mathematics and CEMAT/IST, Technical University of Lisbon, Portugal |
| Title: | Mathematical Modeling and Numerical Simulations of Blood Coagulation |
| Time: | 3:00-4:00 pm |
| Place: | Blocker 628 |
Blood coagulation is one of the important defense mechanisms preventing the loss of blood following a vascular injury. When the endothelium is damaged a complex physiological process called hemostasis is set into action: the blood vessel diameter is diminished, slowing bleeding, blood platelets get activated and a complex sequence of chemical reactions occurs, leading to the formation of a fibrin clot (thrombus) localized at the site of vessel wall damage.
The process of platelet activation and blood coagulation is quite complicated and not yet completely understood. Numerous experimental studies recognize that thrombus formation rarely occurs in regions of parallel flow, but primarily in regions of stagnation point flows, within blood vessel bifurcations, branching and curvatures. Moreover, internal cardiovascular devices such as prosthetic heart valves, ventricular assisting devices and stents, generally harbor high hemodynamic shear stresses that can cause platelet activation and result in coagulation. Thrombotic deposition encountered in these devices is a major cause of their failure. Valid models of the blood coagulation process are essential for better design of these devices and also to identify regions of the arterial tree susceptible to the formation of thrombotic plaques and possible rupture in stenosed arteries.
A number of researchers have attempted to tackle this challenging problem. Recently a phenomenological comprehensive model for clot formation and lysis in flowing blood that extends existing models to integrate biochemical, physiologic and rheological factors, has been developed. The aim of this talk is to present numerical results for this model. The three-dimensional numerical simulations are obtained for a shear-thinning blood flow model in a straight vessel, using a finite volume semi-discretization in space and a three-stages Runge-Kutta time integration method. These are preliminary results aimed at showing the validation of the model and of the numerical code.
Last revised: 04/07/07 By: christov@math