体循环系统建模与仿真

根据流体网络与电气网络的等效关系,用电流表示血液的流动,用电阻表示血液流动的黏滞阻力,用电容表示血管的顺应性,用电感表示血流的惯性.采用1个时变电容和1个心肌电阻模拟左心室,建立了改进型五阶集总参数体循环系统电路模型.根据人体实际生理状况和临床数据制定模型参数,仿真健康心脏、不同部位病变导致的衰竭心脏的血流动力学特性,探讨了衰竭心脏的仿生控制机理,验证了所建模型的可行性.根据基础电路法列写状态方程,应用MATLAB软件进行仿真.结果表明:改进的左心室模型能全面地反映心脏的工作机理和功能,可以模拟健康状态血液动力学特性,通过改变参数又可以模拟因左心室弹性变化、外周阻力变化、心肌阻抗特性变化分别导致心衰的血流动力学特性.

Modeling and simulation of systemic circulation system

According to the equivalent relations of fluid network,electrical network,current,resistors,capacitors and inductors were respectively represented by blood flow,hydraulic viscous resistance,compliance and inertance.The left ventricle was modeled by a time-varying capacitance and myocardial impedance to establish fifth-order lumped parameter systemic circulation electric circuit model.Based on the real physiological conditions and clinical data of human being,the model parameters were determined.The hemodynamics of normal heart and failure heart caused by different part diseases were simulated to investigate the bionic control mechanism of heart failure,and to verify the feasibility of the proposed model.According to basic circuit analysis methods,the state equations were deduced and simulated by MATLAB.The results show that the modified left ventricle can comprehensively reflect the working mechanism and function of heart,and can simulate the hemodynamics of normal heart.The hemodynamics of the heart failure caused by left ventricle elastance,systemic vascular resistance or myocardial impedance can be simulated by changing model parameters.