• Korea-Australia Rheology Journal
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• v.20 no.4
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• pp.189-196
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• 2008

The pulsatile flow of blood through a stenosed artery under the influence of external periodic body acceleration is studied. The effect of non-Newtonian nature of blood in small blood vessels has been taken into account by modeling blood as a Casson fluid. The non-linear coupled equations governing the flow are solved using perturbation analysis assuming that the Womersley frequency parameter is small which is valid for physiological situations in small blood vessels. The effect of pulsatility, stenosis, body acceleration, yield stress of the fluid and pressure gradient on the yield plane locations, velocity distribution, flow rate, shear stress and frictional resistance are investigated. It is noticed that the effect of yield stress and stenosis is to reduce flow rate and increase flow resistance. The impact of body acceleration is to enhance the flow rate and reduces resistance to flow.

• Journal of Korean Neurosurgical Society
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• v.46 no.5
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• pp.488-491
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• 2009

A 31-year-old man presented with right hemiparesis, and magnetic resonance imaging revealed a small infarct at left basal ganglia. Digital subtraction angiography showed left cervical internal carotid artery (ICA) occlusion and severe stenosis of the ipsilateral external carotid artery (ECA) with collateral cerebral circulation fed by ECAs. Based on the results of a functional evaluation of cerebral blood flow, we performed preventive ECA angioplasty and stenting for advanced ECA stenosis to ensure sufficient blood flow to the superficial temporal artery. Eight weeks later, superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis was performed. His postoperative course was uneventful and no additional transient ischemic attacks have occurred. To our knowledge, this is the first report of preventive angioplasty and stenting for advanced narrowing of an ECA before STA-MCA anastomosis for ipsilateral ICA occlusion.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.111-115
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• 1997

The objective of present study is to obtain information about stenosis effects on the blood flow in the coronary artery bifurcation. The three dimensional steady of blood in the coronary artery bifurcation with stenosis and without stenosis are simulated using the finite volume method. Apparent viscosity of blood is represented as a function of shear rate by the Carreau models. Velocities vectors and wall shear stresses along the branch tubes with stenosis are compared with those of without stenosis for steady flows. Flow phenomena in the stenosed branch tubes are discussed extensively.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.8 no.2
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• pp.5-17
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• 2002

The aim of study carried out to determine the effects of myofascial release on the cranial arteries velocity from November 11, 2001 to March 29, 2002 the objects were 10 patients who having the tension-type headache at H-hospital This research compared with measure the mean flow velocity middle cerebral artery, posterior cerebral artery, vertebral cerebral artery. Result obtain were as follows; 1. Middle cerebral artery blood velocity between pre treatment and after treatment for 10days experiment was significantly increased 9.76cm/s(p<0.05)in right, 4.88cm/s(p<0.05)in left. 2. Posterior cerebral artery blood velocity between pre treatment and after treatment experiment was difference 6.35cm/s(p<0.01)in right, 5.14cm/s(p<0.01)in left, between pre treatment and after treatment for 5days experiment was 11.48cm/s(p<0.01)in right, 10.74cm/s(p<0.01)in left, between pre treatment and treatment for 10days experiment was 12.92cm/s(p<0.001) in right, 12.68cm/s(p<0.001) in left. 3. Vertebral artery blood velocity between pre treatment and post treatment experiment was difference 4.48cm/s(p<0.05)in right, 6.10cm/s(p<0.05) in left, between pre treatment and after treatment for 5days experiment was 12.50cm/s(p<0.001)in right, 14.40cm/s(p<0.001)in left, between pre treatment and after treatment for 10days experiment was 14.70cm/s(p<0.001)in right, 13.90cm/s(p<0.001)in left.

• The Korean Journal of Nuclear Medicine
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• v.26 no.1
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• pp.40-48
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• 1992

Gated blood pool scan is frequently used for evaluating the change in cardiac function in various cardiac diseases. But resting gated blood pool scan using only LVEF as a cardiac index has been consitently shown to have a low sensitivity, which is about 50%, in detecting coronary artery disease. So it is recommended to compare exercise gated blood pool scan to resting gated blood pool scan. Exercise tests, however, are not always possible, especially in patients with musculoskeletal diseases, recent myocardial infarction and in elderly persons. We studied the usefulness of resting gated blood pool scan using multiple indices in evaluating the patients with coronary artery disease. Studied cases were 185 patients with coronary artery disease (angina pectoris 31, myocardial infarction 154) and 25 normals with low likelihood of coronary artery disease. We used $^{99m}Tc-labeled$ RBC, 740 MBq labeled by in vivo method. The data were evaluated by Micro DELTA computer program. The results were as following: 1) The ejection rates (PER, AER) and filling rates (PFR, AFR) were different in normls and patients with angina pectoris or myocardial infarction. 2) Mean phase angle, ejection rates and filling rates could separate normals from coronary artery disease patients with normal LVEF. 3) Regional ejection fraction was decreased at the site of the infarct in patients with myocardial infarction. 4) Peak filling rate was the the most detectable index in evaluation of cardiac function in patients with coronary artery disease. 5) The threshold at 1.5 standard deviation of normal range was considered as the most reliable cut-off value from ROC analysis. These data suggest that the resting gated blood pool scan has an important role in the evaluation of cardiac functional changes using various cardiac indices in patients with coronary artery disease.

• Journal of Korean Neurosurgical Society
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• v.56 no.6
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• pp.500-503
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• 2014

If a ruptured blood blister-like aneurysm (BBA) arises from the lateral or superolateral wall of the internal carotid artery (ICA) at the level of the anterior choroidal artery (AChA), its proximity to the origin of the AChA presents a serious surgical challenge to preserve the patency of the AChA. Two such rare cases are presented, along with successful surgical techniques, including the application of a C-shaped aneurysm clip parallel to the ICA and a microsuture technique to repair the arterial defect. The patency of the AChA and ICA was successfully preserved without recurrence or rebleeding of the BBA during a 1-year follow-up after the operation.

• Korean Journal of Veterinary Research
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• v.6 no.1
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• pp.57-75
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• 1966

This study was conducted to observe the condition of the ramifications of the bronchus and pulmonary blood vascular system by injecting the vinylite into the bronchial tree and pulmonary blood vessels in 100 normal adult dogs. The results obtained were summarized as follows: 1. Lungs of dog were composed of the same pulmonary territories as in lungs of human. 2. Cardiac lobe corresponding to R.medio-bassalis of human lungs was well developed and situated as a independent cardiac lobe, in ventral side of right lung. 3. Bronchial tree were in the patterns of axial divergency and blood vascular systems were (in general) branched along the bronchial tree, arteries lying near the bronchial tree but veins apart from it. 4. Among the branching patterns of bronchus pulmonary artery and pulmonary vein in each lobe, the type presented most frequently were noted, which were designated basic type by the author. 5. Pulmonary blood vessels were not always branched in accordance with bronchial tree, diverged inmore complex patterns, especially in venous vascular system. 6. Ramus anterior (lobe apicalis) was always observed in all casting specimen. 7. There was a case of peculiar variation patterns of the ramification in the bronchi directing into the left apical and cardiac lobe, arose respectivelly, at independent origin of bifurcation in the left bronchial stem, and a case of peculiar variation pattern of the artery entering left apical lobe and cardiac lobe, had a same origin of the bifurcation at rami pulmonary artery, and then divided respectivelly into the rami medi artery and rami left apical lobe artery. 8. In the classification based on the patterns of bronchial and blood vasculor divergencys, there were a lot of significant combination cases in their patterns.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.2043-2047
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• 2003

The distributions of blood pressure, blood flow, and blow volume in the left common artery (LCCA) were determined using the lumping parameter method. In order to develop a mathematical model for microcirculation in LCCA, the present study adopted preexisted set of measured morphological data on anatomy, mechanical properties of the coronary vessels, viscosity of blood, the basic laws of physics, and the appropriate boundary condition. Pressures and volumes of blood and flow resistance were expressed in terms of electrical voltages, current, and resistances, respectively, in the electrical analog model. The results of two mathematical models, symmetrical and asymmetrical models, were compared with other investigator's data. The present results were in good agreement with previous studies. It was found that the mean pressure profiles were similar in both models.

• Journal of Biomedical Engineering Research
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• v.18 no.2
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• pp.179-186
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• 1997

Steady and physiological flows of a Newtonian fluid and blood in the abdominal gorta/iliac artery bifurcation are numerically simulated to understand the etiology and pathogenesis of atherosclerosis. Distributions of velocity, pressure, and wall shear stress in the bifurcated arterial vessel model are calculated to investigate the differences of flow characteristics between steady and physiological flows and to compare flow characteristics of blood with that of a Newtonian fluid For the given Reynolds number the flow characteristics of physiological flows for a Newtonian fluid and blood in the bifurcated arterial vessel are quite different from thcse of steady flows. No flow separation or flow reversal in the bifurcated region appears downstream of a stenosis during the acceleration phase. However, during the deceleration phase the flow exhibits flow separation in the outer walls of daugtlter branches, which extends to the entire wall region.

• Journal of information and communication convergence engineering
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• v.16 no.4
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• pp.258-263
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• 2018

Color Doppler sonography is a useful tool for examining blood flow and related indices. However, it should be done by well-trained operator, that is, operator subjectivity exists. In this paper, we propose an automatic blood flow area extraction method from brachial artery that would be an essential building block of computer aided color Doppler analyzer. Specifically, our concern is to examine hypertension suspicious (prehypertension) patients who might develop their symptoms to established hypertension in the future. The proposed method uses fuzzy C-means clustering as quantization engine with careful seeding of the number of clusters from histogram analysis. The experiment verifies that the proposed method is feasible in that the successful extraction rates are 96% (successful in 48 out of 50 test cases) and demonstrated better performance than K-means based method in specificity and sensitivity analysis but the proposed method should be further refined as the retrospective analysis pointed out.