Influence of magnetic field and Hall currents on blood flow through a stenotic artery

A micropolar model for blood simulating magnetohydrodynamic flow through a horizontally nonsymmetric but vertically symmetric artery with a mild stenosis is presented. To estimate the effect of the stenosis shape, a suitable geometry has been considered such that the horizontal shape of the stenosis can easily be changed just by varying a parameter referred to as the shape parameter. Flow parameters, such as velocity, the resistance to flow （the resistance impedance）, the wall shear stress distribution in the stenotic region, and its magnitude at the maximum height of the stenosis （stenosis throat）, have been computed for different shape parameters, the Hartmann number and the Hall parameter. This shows that the resistance to flow decreases with the increasing values of the parameter determining the stenosis shape and the Hail parameter, while it increases with the increasing Hartmann number. The wall shear stress and the shearing stress on the wall at the maximum height of the stenosis possess an inverse characteristic to the resistance to flow with respect to any given value of the Hartmann number and the Hall parameter. Finally, the effect of the Hartmann number and the Hall parameter on the horizontal velocity is examined.

Mathematical modeling and parametric investigation of blood flow through a stenosis artery

In this study,a mathematical model is formulated to examine the blood flow through a cylindrical stenosed blood vessel.The stenosis disease is caused because of the abnormal narrowing of flow in the body.This narrowing causes serious health issues like heart attack and may decrease blood flow in the blood vessel.Mathematical modeling helps us analyze such issues.A mathematical model is considered in this study to explore the blood flow in a stenosis artery and is solved numerically with the finite difference method.The artery is an elastic cylindrical tube containing blood defined as a viscoelastic fluid.A complete parametric analysis has been done for the flow velocity to clarify the applicability of the defined problem.Moreover,the flow characteristics such as the impedance,the wall shear stress in the stenotic region,the shear stresses in the throat of the stenosis and at the critical stenosis height are discussed.The obtained results show that the intensity of the stenosis occurs mostly at the highest narrowing areas compared with all other areas of the vessel,which has a direct impact on the wall shear stress.It is also observed that the resistive impedance and wall shear pressure get the maximum values at the critical height of the stenosis.

Couple stress nanofluid flow through a bifurcated artery—Application of catheterization process

In this article,we are exploring the hemodynamics of nanofluid,flowing through a bifurcated artery with atherosclerosis in the presence of a catheter.For treating obstruction in the artery,one can use the catheter whose outer surface is carrying the drug coated with nano-particles.The resultant solvent is considered as blood nano-fluid.Blood being a complex fluid,is modeled by couple stress fluid.In the presence of nano-particles,the temperature and the concentration distribution are understood in a bifurcated stenotic artery.The concluded mathematical model is governed by coupled non-linear equations,and are solved by using the homotopy perturbation method.Consequently,we have explored is the effects of fluid and the embedded geometric parameters on the hemodynamics characteristics.It is also realized that high wall shear stress exists for couple stress nano-fluid when compared to Newtonian nano-fluid.which is computed at a location corresponding to maximum constriction(z=12.5)of the artery.

A Study for Analyzing the Effect of Overlapping Stenosis and Dilatation on Non-Newtonian Blood Flow in an Inclined Artery

The stenosis in the artery, which reduces the flow passage to blood, is a common cardiovascular disease that is responsible even for cardiac arrest sometimes. The hemodynaics reveals that the severe blockage in an artery due to stenosis generates pressure tangential stress that impacts adversely on the arterial wall downstream to stenosis and weakens the arterial wall. The site of weakened wall in the artery generates post stenotic dilatation. The objective of this paper is to study flow of blood, of non-Newtonian in nature described by Herschel-Bulkley model, in a diseased artery suffering with partly overlapped two stenoses and a dilatation distal to the stenoses. A mathematical model, describing the blood flow, has been derived using Navier-Stokes equations along with the prescribed geometry of the diseased artery. The expressions of velocity profile, resistive impedance to flow and wall shear stress (skin-friction) are derived. The effect of inclination of the vessel on the resistive impedance to flow is discussed along with the effect of rheological and geometrical parameters on the resistive impedance to flow and skin friction.

Percutaneous transluminal stenting in patients with carotid artery stenosis

Objective To assess the efficacy and safety of percutaneous transluminal stenting for patients with carotid artery stenosis.Methods Selective percutaneous transluminal stenting was performed for patients with symptomatic carotid artery stenosis(luminal narrowing ≥ 70%).Success rates and complications associated with the procedures were observed.During six months of follow-up,both recurrent symptom and restenosis rates were recorded.Results There were 17 bifurcating lesions among 27 stenoses in 26 patients,of whom 18 had concomitant coronary artery diseases.The acute procedural success rate was 96.3%(26/27),and the degree of stenosis was reduced from 88.6% ± 8.9%(range 70 - 100)to 0.4% ± 2.0%(range 0 - 10).Six patients developed severe bradycardia and hypotension,and 3 experienced transient loss of consciousness during balloon dilatation.During hospitalization,2 patients experienced loss of consciousness and convulsion,respectively,due to hyperperfusion,and both recovered 12 hours later.There were 2 minor stroke cases (7.4%)but no cases of major stroke or death.At the 6-month follow-up,there were no cases of TIA or new onset of stroke.There was no restenosis detected in 16 cases using angiography and in 10 cases using MRI in 6 to 16 months of follow-up.Conclusions Percutaneous transluminal stenting for patients with carotid artery stenosis has a high procedural success rate with few and acceptable complications.Few patients suffered from recurrent symptoms or showed restenosis in long-term follow-up.

A mathematical analysis of MHD blood flow of Eyring-Powell fluid through a constricted artery

The present study deals with the flow of blood through a stenotic artery in the presence of a uniform magnetic field. Different flow situations are taken into account by considering the regular and irregular shapes of stenosis lying inside the walls of artery. Blood inside the artery is assumed to be Eyring-Powell fluid. A mathematical model is developed and simplified under the physical assumptions of stenosis. The regular perturbation method is adopted to find the solutions for axial velocity and pressure gradient. The variations in pressure drop across the stenosis length, the impedance and the shear stress at the walls of stenotic artery are discussed in detail through graphs. It is observed that the Eyring-Powell fluid is helpful in reducing the resistance to the flow in stenotic artery. Moreover, symmetric form of stenosis is more hazardous as compared to asymmetric stenosis.

A HYDROMAGNETIC MATHEMATICAL MODEL FOR BLOOD FLOW OF CARREAU FLUID

This paper constructs a mathematical model for blood flow through an artery with mild stenosis. Constitutive equations for Carreau fluid are employed in the mathematical modeling. Analysis has been carried out in the presence of constant magnetic field. Symmetric and asymmetric shapes of stenosis are taken. Governing flow model is computed for the series solution. Whe flow quantities of interest, for instance, axial velocity, pressure gradient, pressure drop, impedance and shear stress at the walls of stenotic artery are described for various pertinent parameters entering into the problem.