• 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 The Korean Dental Society of Anesthesiology
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• v.2 no.1 s.2
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• pp.15-20
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• 2002

Intravenous anesthesia was compared with inhalation anesthesia in 20 patients of oral and maxillofacial surgery. The patients were randomly assigned to two treatment groups so that 20 patients were injected ketamine and propofol and 20 patients were administered enflurane. The hemodynamic responses of patients and recovery profile of the two groups were compared. Intravenous anesthesia group awoke significantly faster than inhalation anesthesia after operation. Time to full recovery in intravenous anesthesia group was significantly shorter than that of inhalation anesthesia group. We conclude that intravenous anesthesia is a practical technique for oral and maxillofacial surgery patients and intravenous anesthesia may be more preferable because of the significant shortness of recovery time.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.5
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• pp.444-450
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• 2008

The conventional studies of the aging effect on cardio-vascular system are mostly obtained from human experiences and can only provide local information. In this study, the effect of fatigue fracture of arterial wall on the blood pressure was investigated by hemodynamic analysis. The aging process was simulated with three stages. The pulse wave velocity increased with age. The systolic blood pressure increases consistently but diastolic blood pressure decreases with age. The simulated results show in good accordance with the clinical ones.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.122-125
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• 1997

It is needless to say that the hemodynamic variables estimation is a very important study or the artificial heart. Even though its importance there have not been satisfactory results which can be applied to the real-world situations. In this paper, we propose a practical afterload model ( AoP, PAP) which can be applied to the real-world situation.

• Journal of Chest Surgery
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• v.21 no.2
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• pp.231-239
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• 1988

Currently numerous methods are in use for myocardial hypothermia as a myocardial preservation modality for cardiac operation. During cardiac ischemia after crystalloid cardioplegia[4C GIK solution], topical cold saline[Group I, a=9], topical ice slush[Group II, n=9] and topical ice chip[Group III, a=10] have been compared for myocardial surface cooling in the isolated rat heart model of cardiopulmonary bypass. During postischemic period, hemodynamic functions[aortic flow, coronary flow, peak aortic pressure and heart rate], biochemical enzymatic activities and cellular injuries with electron microscope were evaluated in this isolated rat heart perfusion model. Postischemic aortic flow, cardiac output and peak aortic pressure in Group I and Group II recovered better than Group III.[p< 0.05] Postischemic creatine kinase and lactate dehydrogenase leakages in Group II and Group III increased more than Group l and postischemic mitochondrial swelling in Group III was more severe than Group I, and Group II.[p< 0.05] These results suggest that topical cold saline was the better method than topical ice slush or topical ice chip as a myocardial preservation modality in the isolated rat heart model of cardiopulmonary bypass.

• The Journal of Internal Korean Medicine
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• v.10 no.1
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• pp.125-136
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• 1989

This study was investigated to clarify the effect of Sin Bee Tang (神秘湯) on the renal function, arterial blood pressure and plasma cortisol. The results obtained were follows; 1. Urine volume and glomerular filtration rate were decreased significantly after Sin Bee Tang water extract, 0.1ml/kg, administration. 2. Glomerular filtration rate, renal plasma flow and urinary excretion of electrolytes were increased significantly after Sin Bee Tang water extract, 0.25ml/kg, administration. 3. Plasma cortisol concentration increased significantly after Sin Bee Tang water extract, 0.25ml/kg, administration. These results suggest that the therapeutic action of Sin Bee Tang for 'Su Chun (水喘)' has a relation with the increase of plasma cortisol and renal hemodynamic effect.

• Journal of Biomedical Engineering Research
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• v.10 no.2
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• pp.91-93
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• 1989

We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate.

• YAKHAK HOEJI
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• v.28 no.3
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• pp.149-160
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• 1984

In order to certify the diuretic mechanism of dopamine, this study was performed in dog. The following results were obtained. Dopamine, when given intravenously, produced diuresis, and increased glomerular filtration rate (GFR), renal plasma flow (RPF), and amount of sodium excreted in urine. When infused directly into a renal artery, dopamine elicited a marked diuresis confined only to the infused side, with concomitant rises in osmolar clearance and sodium excretion as well as a slight increase in free water clearance. Simultaneously total renal plasma flow and medullary plasma flow increased markedly with a increase of glomerular filtration rate and renal plasma flow. Medullary concentration gradient of sodium also markedly lowered in the infused kidney. These changes were not observed during mannitol diuresis and renal action of dopamine were not apparent in dog pretreated with haloperidol. From the above experimental results, it is thought that dopamine, when given into a vien or infused directly into a renal artery, induces diuresis, and the mechanism of its action is due to dual actions which are hemodynamic effect along with glomerular filtraction rate, and the increased response in the medullary blood flow.

• Korean Journal of Bronchoesophagology
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• v.1 no.1
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• pp.109-115
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• 1995

High frequency Jet ventilation (HFJV) via cricothyroid membrane puncture contols frequency of ventilation as 20-200/min and persuits adequate gas exchange. HFJV was known to have advantages such as improvement of PaO$_2$, lesser barotrauma, stable hemodynamic effects, good operative field and lesser movement of head. The purpose of this study was to clarify the advantages of HFJV in cases of microlaryngeal surgery which operating time was expected even within 30 minutes. Twenty-eight patients were divided two groups : 1)control group : general endotracheal Intubation anesthesia. 2)experimental group : HFJV via cricothyroid membrane puncture with intravenous anesthesia, frequency 40/min, I/E ratio 40%, driving pressure 40 psi. We analyzed blood pressure, arterial blood gas, score of general condition and recovery time after operation. In conclusion, HFJV via cricothyroid membrane puncture had a good score of general condition and rapid recovery of consciousness, although some accumulation of P$CO_2$and elevation of blood pressure.

• Molecules and Cells
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• v.37 no.6
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• pp.435-440
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• 2014

Hemodynamic shear stress, the frictional force acting on vascular endothelial cells, is crucial for endothelial homeostasis under normal physiological conditions. When discussing blood flow effects on various forms of endothelial (dys)function, one considers two flow patterns: steady laminar flow and disturbed flow because endothelial cells respond differently to these flow types both in vivo and in vitro. Laminar flow which exerts steady laminar shear stress is atheroprotective while disturbed flow creates an atheroprone environment. Emerging evidence has provided new insights into the cellular mechanisms of flowdependent regulation of vascular function that leads to cardiovascular events such as atherosclerosis, atherothrombosis, and myocardial infarction. In order to study effects of shear stress and different types of flow, various models have been used. In this review, we will summarize our current views on how disturbed flow-mediated signaling pathways are involved in the development of atherosclerosis.