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Biomimetic Microsystems for Blood and Lymphatic Vascular Research
Published in Hyun Jung Kim, Biomimetic Microengineering, 2020
Supravalvular aortic stenosis and atherosclerosis share a common pathological change in the blood vessels. Both diseases have narrow arteries, which leads to arterial obstruction. Supravalvular aortic stenosis is a congenital disease caused by mutations that lead to the loss of function of elastin gene in patients (Curran et al. 1993). Atherosclerosis describes a narrowing of arteries by plagues, causing risks to blood flow, and it is also a usual cause of heart failure and strokes. The initial event of atherosclerosis is the accumulation of lipoproteins in the subendothelial space of the arteries and activation of endothelial cells. This triggers the circulating monocytes to adhere to the activated endothelial cells to extravasate into the vessel wall and differentiate into tissue macrophages. These macrophages then further accumulate more lipoproteins, while the SMCs are activated to secrete and deposit excessive amount of ECM proteins. This cascade of events leads to the buildup of plagues in the vessel walls and luminal space of the arteries (Libby, Ridker, and Hansson 2011).
Blood flow
Published in Peter R Hoskins, Kevin Martin, Abigail Thrush, Diagnostic Ultrasound, 2019
The concept of resistance is used to describe how much force is needed to drive the blood through a particular vascular bed. Blood flow is due to the pressure drop between different points along the vessel and also depends on the resistance to the flow. This relationship was described by Poiseuille as: Pressure drop=Flow×Resistance where the resistance to flow is given by: Resistance=Velocity×Length×8π×Radius4
Pulmonary Vascular Mechanobiology
Published in Jiro Nagatomi, Eno Essien Ebong, Mechanobiology Handbook, 2018
Diana M. Tabima Martinez, Naomi C. Chesler
Adequate supply of oxygen to tissues via blood flow is a requirement for survival. These oxygen demands change throughout growth and development and with physiological adaptation in adult life. The blood flow circuit that facilitates the exchange of oxygen and carbon dioxide in the alveolar spaces of the lung is the pulmonary circulation. The right ventricle ejects deoxygenated blood into the pulmonary arterial trunk, which then bifurcates into the left and right main (extralobar) pulmonary arteries. These branch into increasingly smaller arteries within the lung parenchyma (intralobar arteries) that ultimately feed the capillaries. The intralobar pulmonary arteries can be classified sequentially according to their position in the lung. The first generation intrapulmonary arteries are termed segmental arteries; they accompany the bronchi (large airways) and each supply approximately 20 bronchopulmonary segments in humans. The next smaller arteries are termed intra-acinar which accompany the terminal bronchioles that supply the airspaces of the lung or acini. The intra-acinar arteries branch into the microcirculation, which consists of precapillaries, capillaries and postcapillaries.23 Anatomically and functionally, the pulmonary microcirculation is like two membranes or sheets, separating airspaces above and below from a central blood-filled region. Upon leaving the pulmonary microcirculation, blood is collected by the pulmonary venules, which anastamose into the pulmonary veins, which in turn terminate in the left atrium of the heart.
Estimation of arterial pressure through cuffs constructed from different fabrics using simulation modelling
Published in The Journal of The Textile Institute, 2023
Shenela Naqvi, Prasad Potluri, Parthasarathi Mandal, Philip Lewis
Direct or invasive measurement of Blood Pressure (BP) is carried out by direct arterial cannulation. Although this method is accurate but entails discomfort to human subjects (Cheng et al., 2016; Miao et al., 2020). Alternately, in indirect measurement of BP via ausculation, pressure is exerted through an inflatable cuff over the upper arm to stop blood flow in an artery underneath. Inside-cuff pressure at which the blood flow resumes in different phases during cuff deflation manoeuvre is used for the estimation of high (Systolic) and low (Diastolic) blood pressure values. This method does not estimate arterial pressures directly. Indirect measurements are mostly undertaken due to the advantages of avoiding direct arterial puncturing, ease of measurement, routine practice and the possibility of home monitoring.
A likelihood swarm whale optimization based LeNet classifier approach for the prediction and diagnosis of patients with atherosclerosis disease
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
P. Govindamoorthi, P. Ranjith Kumar
Coronary Artery Disease (CAD) may cause by the accumulation of plaque in the coronary arteries. Atherosclerosis is regarded as the disorder at which the plaque built up by means of narrowing the lumens of artery which limits the oxygenated blood flow to heart (CDC 2021). This reduced rate of oxygenated blood is not adequate for muscles of heart which causes pain in arms, neck, shoulder, and chest termed Angina. The complete blockage of the oxygenated blood might cause heart attack. Coronary Artery Heart Disease (CAHD) is a significant source of death in present world. Per year, millions of people die for the use of CAHD, according to the World Health Organization (WHO) (Cassar et al. 2009). Heart disease is basically the cardiac condition that affects the normal action of cardiac activity. The two most important causes for heart failure are narrowing or blocking the coronary arteries when they supply the heart with blood itself. It has been projected that by 2040 more than 30 million people would die from cardiac failure. A variety of CAHD characteristics can affect the heart's structure or function. The detailed and fast diagnosis of cardiac failure faces multiple difficulties (Devi et al. 2022). Therefore, it is important to build a CAHD intelligence model that can predict cardiac disease at a low cost at an early stage. Without the signs, 25% of people who suffer from CAHD die unexpectedly. CAHD is one of the most critical forms of heart disease and cardiovascular disease. A timely cure and knowledge of the symptoms of the disease will decrease CAHD. Many researchers have found that the risk of heart failure rises across several variables (Koyi et al. 2021).
Pulse wave propagation in a deformable artery filled with blood: an analysis of the fifth-order mKdV equation with variable coefficients
Published in Waves in Random and Complex Media, 2021
Ying Yang, Feixue Song, Hongwei Yang
From a hydrodynamics point of view, arterial blood flow is the unsteady flow of incompressible, Newtonian fluid in an expandable cylindrical tube, and the fluid movement is coupled with the vibration of the tube wall. In this section, we took different circumferential and axial stretching ratios to represent the changes in the degree of vascular deformation. Utilizing numerical analysis, the effects of the higher-order nonlinear and dispersion terms, and vascular deformation on pulse wave propagation characteristics and blood flow in arteries are discussed.