• Title/Summary/Keyword: Vascular pressure

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Comparative study of pulse point using hemodynamics (혈류역학을 이용한 촌구와 인영의 특성비교)

  • Shin, Sang-hoon;Park, Dae-hun;Park, Young-jae;Park, Young-bae
    • Journal of Acupuncture Research
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    • v.21 no.5
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    • pp.241-248
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    • 2004
  • Objectives : The purpose of this study is to examine the hemodynamic characteristics of pulse point. Methods : The computational analysis algorithms of arterial tree system was derived. In order to investigate the effect of internal organ on the pulse point, the diameter of celiac artery was reduced by half. Results : The sensitivity of flow change at the Inyoung(Renying) is better than that of the Chongu(Cunkou). but the Inyoung was worse than the Chongu in the point of the left and right symmetry. The pressure changes at the Inyoung and the Chongu were in the similar range. Conclusions : It was found from the result that the Chongu shows the more symmetrical hemodynamic characteristics than the Inyoung.

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Modeling for the Work of Heart and Development of the WOH Medical device (심장운동부하 모델링과 의료장비 개발)

  • Roh, Hyung-Woon;Suh, Sang-Ho
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.501-504
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    • 2006
  • The estimation of the work of heart can be treated as one of the most important parameters for determining the amount of circulating blood needed for harmonious metabolism in the human body. By monitoring the work of heart, one can detect increased work load of heart and start the treatment at the early stage of CHF. Thus it is necessary to estimate the work of heart. The contractility of the left ventricle, the second important parameter for representing the motion of heart, can be estimated through information on the work of heart. In this study, the modified Windkessel model, which has been used for a measure of vascular hemodynamic impedance parameters, was adapted to estimate the work of heart.

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A Comparative Study of the Hemodynamic Hypotheses for the Generation of Atherosclerosis (동맥경화증의 발생에 관한 혈류역학적 가설들에 대한 비교연구)

  • Suh, Sang-Ho;Cho, Min-Tae;Roh, Hyung-Woon;Kwon, Hyuck-Moon
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1915-1918
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    • 2003
  • Atherosclerosis, which is a degenerate disease, is believed to occur in the vascular system due to deposition of cholesterol and low density lipoprotein(LDL) or thrombosis on the blood vessel. Atherosclerosis narrows arterial lumen, which is known as stenosis phenomenon of blood vessel. Pathogenesis of atherosclerosis is thought to occur mainly by aging. Restenosis phenomenon is observed in the same site of insertion of a stent and balloon angioplasty after treatment of interventional theraphy. Several hypothetical theories related to the generation of atherosclerosis have been reported: high shear stress theory, low shear stress theory, high shear stress gradient theory, flow separation and turbulence theory and high pressure theory. However, no one theory clearly explains the causes of atherosclerosis. In the present study the generation of atherosclerosis in the left coronary artery is investigated. The hypotheses are verified by using the computer simulation.

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Numerical modeling of thrombolysis - Effects of nozzle types and ejection velocities

  • Jeong, Woo-Won;Rhee, Kye-Han
    • International Journal of Vascular Biomedical Engineering
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    • v.4 no.2
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    • pp.13-18
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    • 2006
  • Direct injection of a fibrinolytic agent to the intra-arterial thrombosis may increase the effectiveness of thrombolysis by enhancing the permeation of thrombolytic agents into the blood clot. Permeation of fibrinolytic agents into a clot is influenced by the surface pressure, which is determined by the injection velocity of fibrinolytic agents. Computational fluid dynamic methods were used in order to predict clot lysis for different jet velocities and nozzle arrangements. Firstly, thrombolysis of a clot was mathematically modeled based on the pressure and lysis front velocity relationship. Direct injection of a thrombolytic agent increased the speed of thrombolysis significantly and the effectiveness was increased as the ejecting velocity increased. The nine nozzles model showed about 20% increase of the lysed volume, and the one and seventeen nozzles models did not show significant differences. Secondly, thrombolysis was modeled based on the enzyme transport and the fluid flow equations, and quasi steady numerical analysis was performed. Clot lysis efficiency was also increased as injection velocity increased.

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Numerical analysis of the blood flow in coronary artery combining CFD method with the vascular system modeling (혈관계 시스템 모델과 CFD의 결합을 통한 관상동맥 내 혈류의 수치적 해석)

  • Shim Eun Bo;Park Myung Soo;Ko Hyung Jong;Kim Kyung Moon
    • 한국전산유체공학회:학술대회논문집
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    • 1999.11a
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    • pp.152-157
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    • 1999
  • For the simulation of the blood flow in coronary artery, the system modeling of coronary hemodynamics is combined with CFD technique. The blood flow in coronary artery interacts with the global coronary circulation. Especially in case of the coronary artery with stenosis, the interaction plays an important role in the hemodynamics of the circulation. In this study we present a combined numerical approach using both the CFD technique for flow simulation and the global system model of coronary circulation. We use a lumped parameter model for the global simulation of coronary circulation whereas the finite element method is employed to compute the viscous flow field in stenosed coronary artery, The time variation of the pressure drop due to stenosis is obtained from the proposed numerical method. Numerical results shows that the flow resistance and pressure drop due to stenosis has a relatively large value in systole.

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A Study on the Analgesic, Sedative and Antihypertensive activities of ‘Inchungback’ (인중백(人中白)의 진통(鎭痛).진정(鎭靜) 및 혈압강하작용(血壓降下作用)에 관한 연구(硏究))

  • Rho, Young-Soo;Hong, Nam-Doo;Cho, Young-Whan
    • Korean Journal of Pharmacognosy
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    • v.16 no.2
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    • pp.65-72
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    • 1985
  • These studies were conducted to investigate the effect of 'Inchungbaek' water extract on analgesic and sedative actions, the relaxing action of isolated ileums, vasodilating action and blood pressure. The results of these studies were summarized as follows: Analgesic and sedative actions of 'Inchungbaek' were recognized in mice and rats. The relaxing action of isolated ileums were seen in mice and rabbits, antagonist action was seen acetylcholine and $BaCl_2-induced$ contraction of isolated ileums, and then recognized direct action in the ileum smooth muscle. Hypotensive and vasodilating actions due to vascular smooth muscle relaxation were noted in rabbits and cats.

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Influence of berberine on the blood pressure of rabbits

  • Ko, Suk-Tai;Lim, Dong-Yoon
    • Archives of Pharmacal Research
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    • v.3 no.1
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    • pp.23-30
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    • 1980
  • Berberine, when administered into a ear-vein of the rabbit anesthetized with urethane, produced a long-lasting, dose related fall in blood pressure, but intraventricular berberline did not elicit the hypotensive response. This hypotensive activity of berberine was not influenced by pretreatment of vagotomization and atropine. Depressor responses induced by berberine were not impaired by diphenhydramine, chlorisondamine, guanethidine and propranolol, but reduced significantly by phentolamine pretreatment. Berberine attenuated markedly prossor responses of norepinephrine and epinephrine. These results suggest that berberine causes the hypotensive activity that is attributable to alpha adrenoceptor blockade, but not to a direct relaxant effect upon vascular smooth muscle.

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Studies on the Effects of Evodiae Fructus on the Cardiovascular System in N-nitro-L-arginine Methyl Ester-induced Hypertensive Wistar Rats (오수유가 N-nitro-L-arginine methyl ester로 유발한 고혈압흰쥐의 심혈관계에 미치는 영향)

  • 정수연;이숙영;유태무;안미령;최현진;정면우;류항묵;양지선
    • YAKHAK HOEJI
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    • v.43 no.3
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    • pp.397-403
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    • 1999
  • The present study examined the effect of a methanol extract of Evodiae Fructus on the cardiovascular function in N-nitro-L-arginine methyl ester (NAME)-induced hypertensive Wistar rats after treatment over 6 weeks. In rats treated with NAME, blood pressure, weight of heart, aorta media thickness and media/lumen ratio significantly (p<0.05) increased, whereas coronary flow and heart rate of isolated heart significantly (p<0.05) decreased compared with control group at 6 weeks. In rats treated with NAME and Evodiae Fructus, blood pressure, aorta media/lumen ratio significantly(p<0.05) decreased compared with NAME treated group at 6 weeks. These results suggest that Evodiae Fructus is applicable to the treatment of hypertension and vascular hypertrophy.

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Pharmacological and medical applications of Panax ginseng and ginsenosides: a review for use in cardiovascular diseases

  • Kim, Jong-Hoon
    • Journal of Ginseng Research
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    • v.42 no.3
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    • pp.264-269
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    • 2018
  • Panax ginseng, also called Asian or Korean ginseng, has long been traditionally used in Korea and China to treat various diseases. The major active ingredients of P. ginseng are ginsenosides, which have been shown to have a variety of therapeutic effects, including antioxidation, anti-inflammatory, vasorelaxation, antiallergic, antidiabetic, and anticancer. To date, approximately 40 ginsenoside components have been reported. Current research is concentrating on using a single ginseng compound, one of the ginsenosides, instead of the total ginseng compounds, to determine the mechanisms of ginseng and ginsenosides. Recent in vitro and in vivo results show that ginseng has beneficial effects on cardiac and vascular diseases through efficacy, including antioxidation, control of vasomotor function, modulation of ion channels and signal transduction, improvement of lipid profiles, adjustment of blood pressure, improvement in cardiac function, and reduction in platelet adhesion. This review aims to provide valuable information on the traditional uses of ginseng and ginsenosides, their therapeutic applications in animal models and humans, and the pharmacological action of ginseng and ginsenosides.

Influence of ${\beta}-Eudesmol$ on Blood Pressure

  • Lim, Dong-Yoon;Kee, Young-Woo
    • Natural Product Sciences
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    • v.11 no.1
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    • pp.33-40
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    • 2005
  • The present study was undertaken to investigate the effects of ${\beta}-eudesmol$, one of various ingredients isolated and identified from the bark of Magnolia obovata Thunberg, on arterial blood pressure and vascular contractile responses in the normotensve rats and to establish its mechanism of action. ${\beta}-Eudesmol\;(30{\sim}300\;{\mu}g/kg)$ given into a femoral vein of the normotensive rat produced a dose-dependent depressor response. These ${\beta}-eudesmol-induced$ hypotensive responses were markedly inhibited in the presence of chlorisondamine (1.0 mg/kg, i.v.) or phentolamine (2.0 mg/kg, i.v.). Interestingly, the infusion of ${\beta}-eudesmol$ (1.0 mg/kg/30min) into a femoral vein made a significant reduction in pressor responses induced by intravenous norepinephrine. Furthermore, the phenylephrine $(10^{-5}\;M)-induced$ contractile responses were depressed in the presence of high concentrations of ${\beta}-eudesmol\;(10{\sim}40\;{\mu}g/ml)$, but not affected in low concentration of ${\beta}-eudesmol\;(2.5{\sim}5\;{\mu}g/ml)$. Also, high potassium $(5.6{\times}10^{-2}\;M)-induced$ contractile responses were greatly inhibited in the presence of ${\beta}-eudesmol\;(10{\sim}40\;{\mu}g/ml)$ in a dose-dependent fashion. Taken together, these results obtained from the present study demonstrate that intravenous ${\beta}-eudesmol$ causes a dose-dependent depressor action in the anesthetized rat at least partly through the blockade of vascular adrenergic ${\alpha}_1-receptors$, in addition to the some unknown mechanism of direct vasorelaxation.