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Key human anatomy and physiology principles as they relate to rehabilitation engineering
Published in Alex Mihailidis, Roger Smith, Rehabilitation Engineering, 2023
Qussai Obiedat, Bhagwant S. Sindhu, Ying-Chih Wang
The cardiovascular system primarily consists of blood, the heart, and all the associated blood vessels. A major function of the cardiovascular system is to work with the respiratory system to allow blood to transport carbon dioxide and oxygen. Other major functions of blood include transporting nutrients and body waste, as well as forming a component of the immune system. The heart functions as a pump to push blood to various organs including muscles, brain, and lungs. Generally, arteries are blood vessels that carry oxygenated blood away from the heart. Likewise, veins are blood vessels that carry deoxygenated blood toward the heart. For example, vertebral arteries travel away from the heart, up through the neck, to carry oxygenated blood to the brain. An exception to this rule is that the pulmonary artery carries deoxygenated blood away from the heart to the lungs and the pulmonary vein carries oxygenated blood from the lungs to the heart. A blockage of blood supply to an organ may result in cell death due to lack of oxygen and nutrients as well as due to an inability to remove waste products. For example, with regards to brain tissue, a sudden loss of blood supply to a region of the brain is described as ischemia. Further, a sustained ischemic condition results in necrosis (cell death) of an area of the brain and is described as an infarct. Furthermore, an infarct that presents with local neurological deficits is described as a stroke (Lundy-Ekman 2013).
Swarm Intelligence for Diagnosis of Arrhythmia and Cardiac Stenosis
Published in Shikha Agrawal, Manish Gupta, Jitendra Agrawal, Dac-Nhuong Le, Kamlesh Kumar Gupta, Swarm Intelligence and Machine Learning, 2022
K Sujatha, NPG Bhavani, B Latha, K Senthil Kumar, T Kavitha, U Jayalatsumi, A Kalaivani, V Srividhya, B Rengammal Sankari
Rheumatic heart disease damages the cardiac muscles and valves due to rheumatic fever, caused by streptococcal bacteria. Genetic factors contribute to congenital heart disease like hole in the heart, malfunctioning of heart valves and chambers. All these defects arise due to alcohol consumption, usage of medicines like warfarin during the pregnancy period, infections like rubella, malnutrition and consanguinity. Stroke occurs due to interrupted blood supply to the brain which may happen due to blockage (ischaemic stroke) or bursting of a blood vessel (haemorrhagic stroke). Deaths from cardiovascular diseases (CVDs) and advancing age prove to be challenge in the field of medicine [9].
Central nervous system
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
An aneurysm is a weakening in the blood vessel, which leads to localised ‘ballooning’ in the vessel wall. About 1.5–5% of the general population has or will develop a cerebral aneurysm, but most are asymptomatic. Between 0.5 and 3% of people with a brain aneurysm may suffer from bleeding. Most brain aneurysms present after the age of about 40, at branching point of arteries. They may enlarge slowly and become weaker as they grow, just as a balloon becomes weaker as it stretches. Aneurysms may be associated with other types of blood vessel disorders, such as fibromuscular dysplasia, cerebral arteritis or arterial dissection, but these are very unusual.
Identification of retinal diseases based on retinal blood vessel segmentation using Dagum PDF and feature-based machine learning
Published in The Imaging Science Journal, 2023
K. Susheel Kumar, Nagendra Pratap Singh
The eyes are the important organs in the human body, comprising more than two million cells and tissues. The light-sensitive tissues behind the eyes are called the retina, which captures the view and forwards towards the brain through nerves [1]. The variations in the blood vessels of the retina cause retina artery occlusion, diabetic Retinopathy, retinal vein occlusion, hypertensive Retinopathy etc. The variations in the retinal blood vessels (RBV) cause vision problems and must be detected early to prevent vision loss [2]. The variations in blood vessel types include arteries, arterioles, capillaries, venules and veins. The arteries possess a significant role in organ nourishment with blood and nutrients. Elastic and muscular are the two main forms of arteries. The arterioles render blood over the organs, mainly comprised of smooth muscles. The metabolites and nutrients are exchanged through thin capillary walls made up of a single endothelial layer. The venules are the smallest veins that obtain blood from capillaries for oxygen transfer. The blood flows from venules over the larger, thin-walled, less elastic veins. The inherent retinal disease (IRD) is the most common cause of severe vision problems; thus, early detection would minimize the risk of vision problems in family members [3]. Therefore, a deep insight into these issues is required to protect patients with retinal diseases. Diagnosis of vision complications is tedious; in some cases, only small variations occur between the affected and normal blood vessels [4]. Advances and screening methods are useful for identifying various retinal diseases [5].
Computer-aided detection and characterization of stroke lesion – a short review on the current state-of-the art methods
Published in The Imaging Science Journal, 2018
Stroke is one of the major reasons for death in both grown-ups and elderly people far and wide. Every year, around 20 million individuals experience the impact of stroke and out of these 5 million will be prone to death [1]. Developing countries account for 85% of death cases due to stroke [2]. The global count of the stroke patients takes the third place, after heart attack and cancer. A stroke is usually brought about by the interruption of the blood supply to the brain, normally in view of a burst in a blood vessel or if obstructed by a clot. This prevents the supply of oxygen and supplements, bringing harm to the brain tissue. Essentially, there are two types of stroke, namely ischaemic stroke and haemorrhagic stroke. Ischaemic stroke occurs due to an obstruction inside a blood vessel supplying blood to the brain [3]. It represents 87% of all stroke cases. Haemorrhagic stroke occurs when a weakened blood vessel bursts. Two sorts of weakened blood vessel normally cause haemorrhagic stroke, namely aneurysms and arteriovenous malformations. At the same time, the most well-known reason for haemorrhagic stroke is the uncontrolled high blood pressure (hypertension).
Role of the left coronary artery geometry configuration in atherosusceptibility: CFD simulations considering sPTT model for blood
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
E. Miranda, L.C. Sousa, C.C. António, C.F. Castro, S.I.S. Pinto
With the aging of the human being, there is a tendency to develop cardiac pathologies. Due to the high mortality rate sustained by them, these pathologies are the subject of many studies. According to World Health Organization statistics, coronary artery diseases, such as atherosclerosis, are responsible for a high percentage of mortality, killing more than 7 million people per year (Mackay and Mensah 2004). Atherosclerosis is a chronic inflammatory reaction that occurs in specific places of the arterial walls due to the constant deposition of cholesterol and fatty proteins in the inner layer of blood vessels (Drake et al. 2015). Throughout the agglomeration of the substances, smooth muscle tissue cells proliferate and migrate from the medium layer to the inner layer of the arterial wall. Growing across the disintegrated fibrocellular tissue, the smooth muscle tissue cells create a thin fibrous layer (Bentzon et al. 2014). The successive formation of atherosclerotic plaque leads to narrowing (stenosis), inflexibility and complacency of the vessel, resulting in the decay of blood flow (ischemia) (Betts et al. 2013). In addition to ischemia, when the shear stress between the fluid and the arterial wall increases, thrombosis can occur (Libby and Theroux 2005; Sakakura et al. 2013; Bentzon et al. 2014). Depending on the severity of the problem, irregular flow and oxygen deprivation can cause irreparable damage to the heart muscle and can even lead to death. For this reason, the knowledge of the hemodynamics in coronary arteries is of extreme importance since blood flow behaviour influences the appearance and development of atherosclerosis.