基于主动脉内血泵的集中参数模型研究

目的为研究主动脉内血泵出入口的压力差和血液流率之间的关系,并以此预测血泵的血流动力学参数,建立主动脉内血泵非线性集中参数模型。方法该模型依靠血泵本体参数,不包含循环系统的血流动力学参数。模型包括:电流源,与血泵转速相关,表示被血泵叶轮推出的流率;内阻,用来模拟主动脉内血泵径向间隙之间的阻力;电感,表示流过主动脉内血泵径向间隙的血液的惯性。结果模型可模拟从肺淤血到心室塌陷等各种心脏的生理状态。通过模型得到了血泵的特征方程,方程中参数值由体外循环实验确定。结论通过比较预测血泵压力差和实际测量压力差验证特征方程准确性,结果显示误差小于5%,因此该模型能够准确预测血泵压力差。

Research on lumped parameter model based on intra-aorta pump

Objective Try to set up a nonlinear lumped parameter model of intra-aorta pump by studying the relationship between the pressure difference and the blood flow rate at the head of the pump, so as to predict the hemodynamic parameters of the pump. Methods Only the parameters of the pump, without hemodynamic parameters of the circulating system, were used to esfablish the model. It was composed of a speed-controlled current source representing the flow rate driven by impeller, an internal resistant representing the resistance of the radial clearance, an inductance denoting the inertance of the blood. Results The model could simulate the physiological status of the heart under all the situations from pulmonary congestion to ventricular collapse. The characteristic equation of the pump was derived with parameters determined by experimental data in vitro. Conclusions To verify the accuracy of the model, the prediction value calculated from the model was compared with the one recorded from experiment in vitro. The results showed that the error in between was less than 5%, which indicated that this model could predict the pressure difference of the pump accurately.