Modeling of Deposition of Low Density Lipoprotein (LDL) in Carotid Artery
Mirbagheri, Amir | 2012
- Type of Document: M.Sc. Thesis
- Language: Farsi
- Document No: 43093 (08)
- University: Sharif University of Technology
- Department: Mechanical Engineering
- Advisor(s): Saeedi, Mohammad Saeed
- Atherosclerosis is one of the most important and common causes of death in the world. Atherosclerosis typically affects medium and large arteries in the body and it leads to plaque formation in arterial wall. The first stage of plaque formation has been related to accumulation of low density lipoproteins in arterial wall.
The purpose of this research is presenting a four-layer model to describe the LDL transport in the arterial wall. The endothelium, intima, internal elastic lamina (IEL) and media are all treated as macroscopically homogeneous porous media and the volume-averaged porous media equations are employed to model various layers. The physiological parameters within the various layers are obtained from literature and the diffusion coefficient of endothelium is considered shear dependent.
In addition, an analytical solution is presented for a four-layer porous model for the description of LDL transport in arterial wall. Filtration velocity is modeled by use of equivalent series resistance. Then, LDL transport equation is reduced to a second order differential equation and solved. Next, the results of this analytical solution are used to observe the first stage of LDL accumulation in carotid arterial wall.
In addition, the four-layer model is used to simulate the LDL transport in a 25% stenosis by considering constant physiological parameters and it is concluded that intimal thickening increases the resistance and reduces filtration velocity, consequently.
Then, the intimal growth model is presented and different diseases including hypertension as well as high blood Cholesterol are studied. Finally, a Womersely pulsatile velocity is implemented to observe the effect of shear stress on LDL accumulation in arterial wall. Studying LDL transport in arterial wall by Shear dependent diffusion coefficient, investigating hypertension as well as high blood cholesterol and their influence on intimal growth are considered the innovations in the thesis
- Blood Flow ; Mass Transfer ; Porous Media ; Atherosclerosis ; Low Density Lipoprotein (LDL)