Wall shear stress computation for blood vessels and estimation by machine leaning

Atherosclerosis, a disease of large- and medium-size arteries, is the chief cause of death in the US and most of the western world. It is widely accepted that the focal nature of the disease in arterial bends, junctions, and bifurcations is directly related to locally abnormal hemodynamics, often labeled “disturbed flows.” Employing the aorto-celiac junction of rabbits as a representative atherosclerotic model and considering other branching blood vessels with their distinctive input wave forms, it is suggested that the local wall shear stress gradient (WSSG) is the single best indicator of nonuniform flow fields leading to atherogenesis. Alternative predictors of susceptible sites are briefly evaluated. The results discussed include transient velocity vector fields, wall shear stress gradient distributions, and a new dimensionless parameter for the prediction of the probable sites of stenotic developments in branching blood vessels. Some of the possible underlying biological aspects of atherogenesis due to locally significant |WSSG|-magnitudes are briefly discussed.

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Influence of Intermittent Pneumatic Compression on Wall Shear Stress and Nitric Oxide Levels

ASME 2011 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2011-53670 ◽

2011 ◽

Author(s):

Ganesh Swaminathan ◽

Suraj Thyagaraj ◽

Francis Loth ◽

Susan McCormick ◽

Hisham Bassiouny

Keyword(s):

Nitric Oxide ◽

Shear Stress ◽

Wall Shear Stress ◽

Blood Vessels ◽

Healthy Subjects ◽

Vascular Diseases ◽

Intermittent Pneumatic Compression ◽

Peripheral Vascular ◽

Peripheral Vascular Diseases ◽

Wall Shear

Wall shear stress (WSS) in blood vessels has been shown to play an important role in the development of atherosclerosis. In particular, regions of low and oscillating WSS have been shown to correlate with the localization of atherosclerosis. Thus, we hypothesize that increasing the WSS for patients with peripheral vascular diseases (PVD) will either reduce PVD severity or slow its progression. We analyzed WSS changes from a study by Delis et al. on 32 limbs of PVD patients [1]. Results show that intermittent pneumatic compression (IPC) increases mean WSS by 170% and 240% in PVD patients and healthy subjects, respectively. Peak WSS was found to increase by 93% and 40% in PVD patients and healthy subjects, respectively. In addition, we examined changes in NOX level with use of IPC on five limbs from PVD patients. Our study demonstrated increased NOx levels in subjects after IPC. Further research is needed to determine the benefits of IPC for PVD patients.

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Effects of stenoses on non-Newtonian flow of blood in blood vessels

International Journal of Biomathematics ◽

10.1142/s1793524515500102 ◽

2015 ◽

Vol 08 (01) ◽

pp. 1550010 ◽

Cited By ~ 12

Author(s):

Om Prakash ◽

O. D. Makinde ◽

S. P. Singh ◽

Nidhi Jain ◽

Devendra Kumar

Keyword(s):

Shear Stress ◽

Wall Shear Stress ◽

Blood Vessels ◽

Flow Rate ◽

Homogeneous Fluid ◽

Human Artery ◽

Bingham Plastic ◽

Uniform Cross Section ◽

Flow Through ◽

Wall Shear

In this paper, a mathematical model for steady blood flow through blood vessels with uniform cross-section in stenoses arteries has been proposed. Blood is assumed to be non-Newtonian, incompressible and homogeneous fluid. Blood in human artery is represented as Bingham plastic fluid. Expressions for flow rate, wall shear stress, and resistance to flow against stenoses size have been obtained. Obtained results indicate that stenoses size decreases the flow rate and increases the wall shear stress as well as resistance to flow.

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Turbulent Flow in Constricted Blood Vessels : Quantification of Wall Shear Stress Using Large Eddy Simulation

10.3384/diss.diva-100918 ◽

2013 ◽

Cited By ~ 4

Author(s):

Roland Gårdhagen ◽

Keyword(s):

Shear Stress ◽

Wall Shear Stress ◽

Large Eddy Simulation ◽

Turbulent Flow ◽

Blood Vessels ◽

Eddy Simulation ◽

Large Eddy ◽

Wall Shear

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Variation in wall shear stress in channel networks of zebrafish models

Journal of The Royal Society Interface ◽

10.1098/rsif.2016.0900 ◽

2017 ◽

Vol 14 (127) ◽

pp. 20160900 ◽

Cited By ~ 4

Author(s):

Woorak Choi ◽

Hye Mi Kim ◽

Sungho Park ◽

Eunseop Yeom ◽

Junsang Doh ◽

...

Keyword(s):

Animal Model ◽

Shear Stress ◽

Wall Shear Stress ◽

Blood Vessels ◽

Equivalent Circuit Model ◽

Zebrafish Model ◽

Typical Application ◽

Wall Shear

Physiological functions of vascular endothelial cells (ECs) vary depending on wall shear stress (WSS) magnitude, and the functional change affects the pathologies of various cardiovascular systems. Several in vitro and in vivo models have been used to investigate the functions of ECs under different WSS conditions. However, these models have technical limitations in precisely mimicking the physiological environments of ECs and monitoring temporal variations of ECs in detail. Although zebrafish ( Danio rerio ) has several strategies to overcome these technical limitations, zebrafish cannot be used as a perfect animal model because applying various WSS conditions on blood vessels of zebrafish is difficult. This study proposes a new zebrafish model in which various WSS can be applied to the caudal vein. The WSS magnitude is controlled by blocking some parts of blood-vessel networks. The accuracy and reproducibility of the proposed method are validated using an equivalent circuit model of blood vessels in zebrafish. The proposed method is applied to lipopolysaccharide (LPS)-stimulated zebrafish as a typical application. The proposed zebrafish model can be used as an in vivo animal model to investigate the relationship between WSS and EC physiology or WSS-induced cardiovascular diseases.

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