• 제목/요약/키워드: Hemodynamic

검색결과 866건 처리시간 0.029초

세포-신경계-혈류역학 시스템 통합모델에 의한 심장역학 분석 (Computational analysis of heart mechanics using a cell-autonomic nerve control-hemodynamic system coupled model)

  • 전형민;심은보
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2007년도 춘계학술대회B
    • /
    • pp.2941-2946
    • /
    • 2007
  • A model of the cardiovascular system coupling cell, hemodynamics and autonomic nervecontrol function is proposed for analyzing heart mechanics. We developed a comprehensive cardiovascular model with multi-physics and multi-scale characteristics that simulates the physiological events from membrane excitation of a cardiac cell to contraction of the human heart and systemic blood circulation and ultimately to autonomic nerve control. Using this model, we delineatedthe cellular mechanism of heart contractility mediated by nerve control function. To verify the integrated method, we simulated a 10% hemorrhage, which involves cardiac cell mechanics, circulatory hemodynamics, and nerve control function. The computed and experimental results were compared. Using this methodology, the state of cardiac contractility, influenced by diverse properties such as the afterload and nerve control systems, is easily assessed in an integrated manner.

  • PDF

X선관을 이용한 불투명한 물체 내부 유동의 정량적 가시화 연구 (Quantitative Flow Field Visualization of a Flow inside an Opaque Tube Using Angiographic PIV Method)

  • 김국배;임남윤;류재춘;임대현;이형구;이상준
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2007년도 춘계학술대회B
    • /
    • pp.2935-2940
    • /
    • 2007
  • To diagnose circulatory diseases in the viewpoint of hemodynamics, we need to get quantitative hemodynamic information of blood flows related with the vascular diseases with high spatial resolution of tens micrometer and high temporal resolution in the order of millisecond. For investigating in-vivo hemodynamic phenomena, a new diagnosing technique combining medical radiography and PIV method was newly proposed and developed. This angiographic PIV technique consists of a medical X-ray tube, an X-ray CCD camera, a shutter module for double pulses of X-ray, and a synchronizer. The feasibility of the angiographic PIV technique was tested and quantitative flow velocity field distribution of a flow inside an opaque conduit was acquired by the developed system. It can be used for measuring flow phenomena of nontransparent fluids inside opaque conduits.

  • PDF

인체 심혈관계의 이론적 분석을 위한 시스템 시뮬레이션모델에 관한 연구 (Systemic Simulation Models for the Theoretical Analysis of Human Cardiovascular System)

  • 고형종;윤찬현;심은보
    • 제어로봇시스템학회논문지
    • /
    • 제10권12호
    • /
    • pp.1181-1188
    • /
    • 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.

우주비행 직후 인체 심혈관계의 혈류역학적 변화에 대한 수치적 연구 (Computational analysis of the hemodynamic changes in human cardiovascular system after space flight)

  • 심은보;고형종
    • 한국전산유체공학회:학술대회논문집
    • /
    • 한국전산유체공학회 2000년도 추계 학술대회논문집
    • /
    • pp.123-128
    • /
    • 2000
  • Orthostatic stress in human cardiovascular system following spaceflight remains a critical problem in the current lifercience space program. The study presented in this paper is part of an ongoing effort to use mathematical models to investigate the effects of gravitational stresses on the cardiovascular system of normals and microgravity adapted individuals. We employ a twelve compartment lumped parameter representation of the hemodynamic system coupled to set-point models of the arterial baroreflex and the cardiopulmonary reflex to investigate the transient response of heart rate to orthostatic stress. We simulate current hypotheses concerning the mechanisms underlying postspaceflight orthostatic intolerance over a range of physiologically reasonable values and compare the simulations to astronaut stand-test data pre-and postflight.

  • PDF

수술중 경두개 초음파 집중감시 (Intraoperative Transcranial Doppler Monitoring)

  • 서대원
    • Annals of Clinical Neurophysiology
    • /
    • 제1권1호
    • /
    • pp.70-75
    • /
    • 1999
  • Trancranial Doppler(TCD) monitoring is a new application of ultrasonography which allows the nonivasive detection of blood flow velocity in the horizontal (M1) segment of the middle cerebral artery (MCA) and detects microembolic phenomena in the cerebral circulation. Recent studies emphasized the potential of using this technique in vascular surgery (carotid endarterectomy, cardiopulmonary bypass), interventional and intensive care setting. Although the disparity between CBF and blood flow velocity and number of microemboli could be used to prevent cerebral ischemic and embolism based on clinical studies. A reduction of more than 60% of MCA can reflex hemodynamic ischemic state and acoustic feedback of high intensity transient signals(HITS) from the TCD monitoring unit has a direct influence on surgical technique. TCD monitoring can immediately provide information about thromboembolism and hemodynamic changes, which may be a useful tool in the study and prevention of stroke.

  • PDF