脉搏波传播和血管顺应性对体循环和肺循环系统血流特性和心室功率的影响

本文采用耦合模型研究脉搏波传播和血管顺应性对体循环和肺循环血流特性和心室功率的影响。左心室和右心室均采用Ｅ－Ｒ模型，后负荷系统对于体动脉和肺动脉分别采用Ｔ－Ｙ管模型和稍微不对称Ｔ管模型，应用脉冲响应法将二者耦合起来。选取生理范围的参数，计算了两个系统的每搏输出量（ＳＶ）、每搏输出功（ＳＷ）、定常功率（Ｗs）、脉动功率（Ｗo)和总功率（Ｗt）等。详细分析了血管顺应性、脉搏波波速等对这些参量的影响。得到的主要结果是脉动功率对参数的变化比定常功率更敏感。因此，脉动功率百分比或许是评估心室效率的一个较好参数之一。

INFLUENCE OF PULSE WAVE PROPAGATION AND VASCULAR COMPLIANCE ON BLOOD FLOW OF SYSTEMIC/PULMONARY CIRCULATION AND VENTRICULAR POWER

Effect of pulse wave propagation and vascular compliance on blood flow of the systemic/pulmonary circulation and ventricular power was studied in a model of coupled ventricle/arterial system. Both left and right ventricles were simulated by using E(t) R model. T Y tube model and a newly developed slight asymmetric T tube model with distributed parameter were adopted for systemic/pulmonary arteries after load respectively. Then, impulse respone method was employed to simulate dynamic coupling of systemic and pulmonary circulation. After proper evaluation of the vascular compliance, pulse wave velocity and reflection etc. Parameters, stroke volume (SV) , stroke work (SW) , and steady( s) , oscillatory( o), and total power dissipation( t) in the systemic and pulmonary arteries were calculated. The effect of vascular compliance and pulse wave velocity and reflection on these parameters were analysed in detail. The main conclusion was that the ratio of oscillatory power( o) to total power ( t) might be used as an index of system inefficiency. That is, the greater the portion of t devoted to o , at the expense of steady work ( s ), the less efficient the system.