• 대한수학회지
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• 제43권4호
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• pp.885-897
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• 2006

A new mathematical model of pumping heart coupled to lumped compartments of blood circulation is presented. This lumped pulsatile cardiovascular model consists of eight compartments of the body that include pumping heart, the systemic circulation, and the pulmonary circulation. The governing equations for the pressure and volume in each vascular compartment are derived from the following equations: Ohm's law, conservation of volume, and the definition of compliances. The pumping heart is modeled by the time-dependent linear curves of compliances in the heart. We show that the numerical results in normal case are in agreement with corresponding data found in the literature. We extend the developed lumped model of circulation in normal case into a specific model for arrhythmia. These models provide valuable tools in examining and understanding cardiovascular diseases.

• 제어로봇시스템학회논문지
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• 제10권12호
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• pp.1181-1188
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• 2004

This paper reviews the main aspects of cardiovascular system dynamics with emphasis on modeling hemodynamic characteristics using a lumped parameter approach. Methodological and physiological aspects of the circulation dynamics are summarized with the help of existing mathematical models: The main characteristics of the hemodynamic elements, such as the heart and arterial and venous systems, are first described. Lumped models of micro-circulation and pulmonary circulation are introduced. We also discuss the feedback control of cardiovascular system. The control pathways that participate in feedback mechanisms (baroreceptors and cardiopulmonary receptors) are described to explain the interaction between hemodynamics and autonomic nerve control in the circulation. Based on a set-point model, the computational aspects of reflex control are explained. In final chapter we present the present research trend in this field and discuss the future studies of cardiovascular system modeling.

• Journal of Chest Surgery
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• 제50권2호
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• pp.105-109
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• 2017

Coronary arterial involvement in Takayasu arteritis (TA) is not uncommon. Herein, we describe a case of TA with celiac trunk and superior mesenteric artery occlusion combined with coronary artery disease. Bilateral huge internal thoracic arteries (ITAs) and the inferior mesenteric artery provided the major visceral collateral circulation. After percutaneous intervention to the right coronary artery, off-pump coronary artery bypass grafting for the left coronary territory was done using a right ITA graft and its large side branch because of its relatively minor contribution to the visceral collateral circulation.

• 대한의생명과학회지
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• 제7권1호
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• pp.7-15
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• 2001

Although extracorporeal circulation (ECC) has been routinely used for cardiovascular surgery, hyperoxemia during ECC may produce oxygen toxicity and cellular injury. This study was performed to investigate the clinical influences of hyperoxemic ECC during cardiovascular operation. 40 adult patients scheduled for elective cardiovascular surgery were classified into normoxemic (arterial oxygen tension: 115 mmHg, n＝20) and hyperoxemic (arterial oxygen tension: 380 mmHg, n＝20) ECC. At preoperative and postoperative period, total leukocyte and neutrophil counts, platelet counts, iron, glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), and creatinine in peripheral arterial blood, malondialdehyde (MDA) and troponin-T concentration (TnT) in coronary sinus blood, pulmonary vascular resistance (PVR), and postoperative blood loss volume (BLS) were measured and compared between groups. Hyperoxemic group had postoperatively higher total leukocyte and neutrophil counts, MDA, TnT, PVR total BLS, iron, glucose, AST, ALT, BUN, and creatinine than normoxemic group (p<0.05).0 conclusion, hyperoxemic ECC results in greater inflammatory response and oxidative damaging effects on the heart lung, liver and kidney, probably being adverse to postoperative patient recovery. For reducing these deleterious effects and improving postoperative outcomes, management lowering oxygen tension during ECC is recommended.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.713-716
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• 2002

Aging effect on the cardiovascular circulation is simulated by lumped parameter model. Aging phenomena can be hemodynamically explained as (1) the increase of flow resistance induced by remodeling of artery vessels and increased viscosity of blood and (2) the reduction of the vessel capacitance caused by arteriosclerosis. Appropriate physiological parameters are evaluated from the clinical data of adults and old men. Simulation results well explain the hypertension with aging of cardiovascular system.

• Korean Circulation Journal
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• 제54권2호
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• pp.91-92
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• 2024

• Korean Circulation Journal
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• 제48권11호
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• pp.1028-1029
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• 2018

• Korean Circulation Journal
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• 제52권8호
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• pp.635-637
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• 2022

• 한국비블리아학회지
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• 제27권1호
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• pp.111-134
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• 2016

본 연구는 저자동시인용분석 기법을 이용하여 국내와 미국의 심장혈관학(Cardiovascular Research) 분야의 지적구조 규명을 목적으로 하였다. 이를 위해서 2008년부터 2014년까지 국내의 "대한심장학회지"와 미국의 Circulation, Circulation Research를 선정하여 인용빈도 기준으로 각각 45명과 53명의 저자를 추출하였다. 저자동시인용 행렬을 기반으로 다차원척도분석, 군집분석, 요인분석을 실시하였다. 분석결과는 심장혈관학 분야에서 국내와 미국 연구자들은 공통적으로 여러 분야에 걸쳐 다양한 세부 분야에서 연구 활동을 하는 경향을 보였다. 국내와 미국의 심장혈관학 분야는 핵심연구 영역으로 '심혈관질환 치료', '심혈관질환 진단', '심혈관질환 기초과학', '심혈관질환 예방'으로 나타났다. 국내와 미국의 가장 큰 차이로 볼 수 있는 것은 국내 연구는 임상 중심이며, 미국 연구는 기초 의학 중심인 것으로 나타났다. 국내의 경우는 '리듬장애' 분야가 나타났으며, 이에 반해 미국은 '심혈관계 작용약물' 분야를 찾아볼 수 있다. 또한 미국의 분석결과에서는 기초의학 분야의 세부분야인 '역학', '생물학', '생화학', '생리학' 분야가 뚜렷하게 구분되어 나타났다.

• Korean Circulation Journal
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• 제48권12호
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• pp.1160-1162
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• 2018