颈内动脉狭窄对体循环系统影响的集中参数模型研究

Study on the Influence of Internal Carotid Stenosis on Systemic Circulation in a Lumped Parameter Model

研究颈内动脉病变时对整个颈动脉系统的影响。建立了一个带颈动脉分岔血管分支的体循环系统集中参数模型,基于一组可较好地模拟正常生理曲线的参数,通过改变颈内动脉段的集总参数来模拟颈内动脉狭窄,研究了其对颈动脉系统的影响。结果表明:颈内动脉发生狭窄时,会使其自身的流量、压力和颈总动脉的流量发生显著变化。这些变化主要是由液阻和液容的改变引起的,其中液阻的影响更显著。此外,颈内动脉发生狭窄对于颈外动脉的影响较小,对颈总动脉入口压力则不产生影响。由此说明:利用三维计算模型对颈动脉分岔血管进行血流动力学数值模拟时,入口边界条件用入口压力比用入口流量更合适。

To study the influence on carotid system when internal carotid artery has pathological changes, a lumped parameter model of systemic circulation, which contains carotid bifurcation, was developed. A series of lumped parameters establishing normal physiological pressure and flow rate were obtained. The influence of internal carotid artery （ICA） stenosis on carotid artery system was studied through changing lumped parameters of ICA. The result showsed that the flow rate and pressure of ICA and the flow rate of common carotid artery （CCA） were affected notably when the capacity and resistance of ICA, especially resistance were changed due to the stenosis of ICA. In addition, the flow rate and pressure of external carotid artery （ECA） had insignificant change as well as the pressure of CCA inlet had little change when ICA stenosis occured. It proves that inlet pressure is more reasonable than inlet flow rate as inlet boundary condition in the numerical simulation of hemodynamics of carotid bifurcation using a 3-dimensional model.