【摘要】 目的建立相对便利的血流动力学理论研究体系,进行多状态的综合血液脉动流研究。方法在完全发展脉动流Womerseley算法的基础上引入数值算法,建立基于心动周期里动脉血液流量波的血流动力学求解及分析体系;进而采用理想化的正弦波以及正常生理状态和增强型体外反搏(enhanced external counterpulsation EECP)状态下的在体测量小猪颈动脉血液流量波,进行较全面的血流动力学研究。结果对各状态下的轴向速度分布、壁面切应力(wall shear stress,WSS)分布、震荡剪切指数(oscillatory shear index,OSI)等重要血流动力学量进行心动周期里的求解分析。流量波波形对WSS分布尤其是OSI水平有一定的影响;EECP作用能明显提升心动周期里的动脉WSS水平尤其是WSS峰值,同时也提高了OSI水平。结论所建立的基于血液流量波的求解体系能方便有效地应用于血流动力学研究中;EECP作用在生理范围内大幅提升动脉的WSS水平可能是其良好临床效果的最重要生物力学机制之一;作为当前备受关注的血流动力学指标,OSI对于动脉内皮功能的影响作用可能远小于WSS本身,OSI可能并不是理想的预测动脉粥样硬化病变的血流动力学指标。更多还原

【Abstract】 Objective To conduct a comprehensive study on pulsatile blood flow in arteries by proposing a convenient theoretical research system for hemodynamics. Methods Based on Womersley algorithm for fully developed pulsatile flow,numerical algorithm was introduced to establish the solving and analytical system of hemodynamics based on flow rate in arteries during one cardiac cycle. The flow rate of carotid artery in pig was measured under three blood flow states: the ideal state with a sinusoidal inflow waveform,the normal physiological state and the enhanced external counterpulsation( EECP) state for comprehensive hemodynamic research. Results Important hemodynamic parameters such as the axial speed vector,the wall shear stress( WSS),and the oscillatory shear index( OSI) during one cardiac cycle under the mentioned three flow states were solved respectively. The waveform of flow rate had a certain effect on WSS distributions and OSI level; the EECP performance obviously resulted in a significant increase in the level of WSS( WSS peak in particular) and OSI. ConclusionsThe solving system developed in this paper can be used for hemodynamics study conveniently and effectively. One of the most important hemodynamic mechanisms that lead to EECP’s good clinical effect may lie in its promotion to WSS level under physiological state,but the effect of OSI on endothelial function of the artery might much smaller than WSS itself; therefore,OSI may not be an ideal hemodynamic index for predicting the lesion of atherosclerosis.更多还原