Search for: carotid-bifurcation
0.008 seconds

    Effect of Stenotic Carotid Geometry on Flow and Stroke-risk

    , M.Sc. Thesis Sharif University of Technology Amirkhosravi, Mehrad (Author) ; Firoozabadi, Bahar (Supervisor) ; Saeedi, Saeed (Supervisor)
    Carotid bifurcation is one of the most important bifurcations in human body which has a lot of curvature in some people. The common carotid artery bifurcates into an internal carotid artery (ICA) and an external carotid artery (ECA). The incidence of stenosis in carotid bifurcation and in particular in the internal carotid artery is of special importance. In the United States of America by 2006, nearly 700000 strokes occur each year, with about 160000 deaths and 20 to 30% of strokes are caused by stenotic carotid that cost estimated at $160 billion. The purpose of this thesis is to investigate in hemodynamic factors of blood flow such as velocity variation, vortex patterns, shear stress and... 

    Numerical Multiscale Modelingof Cardiovascular System

    , M.Sc. Thesis Sharif University of Technology Yousefi, Amir (Author) ; Firoozabadi, Bahar (Supervisor) ; Saeedi, Mohammad Saeed (Supervisor)
    One of the main reasons of brain attack is stenosis in Carotid bifurcation. As a result, it's a major field of interest for a large group of scientists including medical doctors and engineers. In the engineering fields a large number of studies have been done on this topic based on Numerical Simulation. As blood boundary conditions in this region strictly depend on the rest of the body's vascular system, the problem is the definition of the boundary condition in this approach. In addition, because of lack of enough hardware sources simulation of the whole blood system is impossible; thus the rest of the system should be simulated based on radical methods with less details. In this project a... 

    Coupling 3D-1D for Blood flow Simulation in Carotid Bifurcation

    , M.Sc. Thesis Sharif University of Technology Chiniforooshan Esfahani, Iman (Author) ; Firoozabadi, Bahar (Supervisor) ; Saeedi, Mohammad Saeed (Supervisor)
    Recently, many investigations are done in the field of the modeling of the cardiovascular system. For the purpose of understanding of this system, mainly the location of formation and development of atherosclerosis, these investigations are so vital. The multi-scale modeling is an appropriate method to reduce the cost of calculation and also, this method simplifies the complicated model of cardiovascular system. This research presents a multi-scale 1D-3D modeling of cardiovascular system. In this model, the three dimensional geometry of carotid bifurcation is coupled with a one dimensional full model of cardiovascular system. We used some user defined function in the Fluent software for... 

    Study the Effect of Considering two Layered wall for Carotid Artery Bifurcation on Distribution of Hemodynamic and Non-Hemodynamic Parameters using a Fluid-Structure Interaction Method

    , M.Sc. Thesis Sharif University of Technology Nikparto, Ali (Author) ; Dehghan Firoozabadi, Bahar (Supervisor) ; Saidi, Mohammad Said (Supervisor)
    It is known today that arterial diseases are among the leading cause of death in modern societies. More than 50% of deaths in western countries are mainly occurred as results of these diseases, namely atherosclerosis. In order to study risk factors and to understand the full process of how arterial diseases initiate and progress, many research topics have been introduced and studied. Researchers believe that mechanical factors such as Wall Shear Stress (WSS), Pressure distribution, Cyclic strain, Back flow zones and many other factors are responsible for initiation of atherosclerosis. Different patterns of Wall Shear Stress and Strain are seen in arteries. Among other factors outlined in... 

    Investigation of wall shear stress related factors in realistic carotid bifurcation geometries and different flow conditions

    , Article Scientia Iranica ; Volume 17, Issue 5 B , 2010 , Pages 358-366 ; 10263098 (ISSN) Jamalian Ardakani, S. S ; Jafarnejad, M ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology
    Cardiovascular diseases are one of the major causes of death in the world; atherosclerosis being one aspect. Carotid bifurcation is one of the sites that are vulnerable to this disease. Wall Shear Stress (WSS) is known to be responsible for the process of atherogenesis. In this study, we have simulated the blood flow for Newtonian and non-Newtonian, steady and unsteady, flow conditions in three idealistic and five realistic geometries. A risk factor has been presented based on the results of wall shear stress and, then, a relation was found between geometrical features and the wall shear stress risk factor. Our main conclusions are: 1) The non-Newtonian behavior of blood elevates the value... 

    Effects of hypertension on Intima-Media Thickness (IMT); application to a human carotid artery

    , Article Scientia Iranica ; Volume 23, Issue 4 , 2016 , Pages 1731-1740 ; 10263098 (ISSN) Mirbagheri, S. A ; Saidi, M. S ; Sohrabi, S ; Firoozabadi, B ; Banazadeh, M. H ; Sharif University of Technology
    Sharif University of Technology 
    A vast number of deaths in the world have been attributed to atherosclerosis. The prominent aim of this study is proposing an accurate and simple model to investigate the process of arterial wall thickening. In order to investigate LDL (Low Density Lipoprotein) accumulation in arterial wall, a four layer model for arterial wall consisting of endothelium, intima, IEL, and media is presented. All layers are treated as homogenous porous media. This model has been solved both numerically and analytically. Obtained accumulated LDL in the intima is used to calculate oxidized LDL flux. Also, the presented model and clinical data are used to prepare the growth model for arterial wall. Furthermore,... 

    Numerical Fluid–Structure Interaction and non-Newtonian Simulation of Blood Flow in a Compliant Carotid Bifurcation

    , M.Sc. Thesis Sharif University of Technology Toloui, Mostafa (Author) ; Firoozabadi, Bahar (Supervisor) ; Saidi, Mohammad Saeid (Co-Advisor)
    Researchers have done a lot of studies about the use of CFS in blood flow modeling in order to improve the supplementary devices or find mechanical factors which cause artery to be diseased. Blood is a complex rheological fluid, blood flow is a pulastile flow, and blood flow field interacts with the deformable vessel wall. Thus, blood flow modeling like other biological phenomena has its own complexities such as anisotropy, vsicoelasticity, and nonlinearity in stress-strain relationship of vessel wall. To explore the role of hemodynamics in the initiation and progression of stenosis in carotid artery bifurcation, a 3D Computational Fluid Dynamics (CFD) technique is applied. The effect of... 

    Computational simulation of non-Newtonian blood flow in carotid bifurcation for investigation the various rheological blood models

    , Article ASME 2007 International Mechanical Engineering Congress and Exposition, IMECE 2007, 11 November 2007 through 15 November 2007 ; Volume 2 , 2007 , Pages 263-270 ; 0791842967 (ISBN) Jahanyfard, E ; Firoozabadi, B ; Goodarzvand Chegini, A ; ASME ; Sharif University of Technology
    American Society of Mechanical Engineers (ASME)  2007
    One of the leading causes for death after heart diseases and cancer in all over the world is still stroke. Most strokes happen because an artery carrying blood from the heart to the brain is clogged. Most of the time, as with heart attacks, the problem is atherosclerosis, hardening of the arteries, calcified build up of fatty deposits on the vessel wall. The primary troublemaker is the carotid artery, one on each side of the neck, the main thoroughfare for blood to the brain. In this study, the fluid dynamic simulations were done in the carotid bifurcation artery for studying the formation of atherosclerosis, and shear thinning behavior of blood as well as Newtonian comportment was studied....