Research On Blood Circulation System And Physiological Control Based On Left Ventricular Assist Device

In recent years,with the change of people’s eating habits and the aging of China’s population,the number of cardiovascular disease population in China is increasing rapidly and tends to be younger.With the passage of time,these cardiovascular diseases will eventually develop into heart failure.Heart transplantation is the best way to treat end-stage heart failure.However,due to the large number of patients and the serious shortage of heart donors,most of the patients with end-stage heart failure can not get effective treatment because of the lack of suitable donors.Ventricular assist device(VAD)is an effective way to solve this problem.On the one hand,VAD can temporarily serve as a bridge for transplantation while the patient is waiting for the donor;on the other hand,VAD can completely replace the heart.In order to fully verify the effectiveness and safety of Va D,it is necessary to establish a system similar to human blood flow environment for Va D testing.The main research work of this paper is as follows:Based on the classical elastic cavity theory and the time-varying elastic theory of the heart,a model of blood circulation system is established.The model integrates the mechanism of aortic pressure reflex.In order to further enable the model to better define and simulate the blood flow environment of patients at different levels of activity,the model integrates the mechanism of dynamic aerobic pressure reflex during exercise.Based on the established blood circulation model,the hemodynamic environment of normal human body,heart failure patients and heart failure patients after VAD transplantation was systematically studied,and the therapeutic effect and risk of VAD transplantation were preliminarily evaluated.Finally,according to the simulation results,this paper proposes some improvements on pump control.This paper mainly focuses on the improvement of pump pulsation flow control,in order to obtain the normal physiological pulsation value of arterial pressure.At the same time,the paper compares the effects of different pump speed waveforms on the arterial pressure pulsation.Finally,the controller is designed and the effectiveness and robustness of the controller are preliminarily verified by simulation.