Design And Development Of A Bi-ventricular Mock Circulatory System With Systemic And Pulmonary Circulations

Heart failure has become a serious disease to human life and health,the incidence rate showed a rising trend.Heart transplant is the most effective treatment to treat end-stage heart failure,but many patients die waiting donor hearts.In the developed countries,ventricular assist devices(VADs)have become viable technology treating end-stage heart failure,replacing/assisting the heart function,reducing the ventricular load,and recovering vital organ perfusion.Mock circulatory systems(MCSs)has been a useful in-vitro test platform for simulating the hemodynamic interaction between VADs as well as other mechanical circulatory support devices and the human circulatory system.The aim of this paper is to design and develop an MCS,which can simulate the physiological condition of health,movement and different stage of heart failure,and mock hemodynamic characteristics cooperating with VAD.On the requirements,this paper is carried out from four aspects: mechanical structure design of hydraulic circuit of MCS,data acquisition and control module,simulation using the Amesim software and experimental verification of MCS.(1)By mathematical modeling and mechanical structure,the parts of the hydraulic circuit,such as ventricle,vascular compliance,peripheral resistance and valve,are designed and made to produce blood pressure and flow parameters corresponding to the parts of the cardiovascular circulation system.(2)The program of data acquisition and control module by Labview is written to collect,calculate,display and save data of parameters generated by hydraulic circuit.(3)The theoretical model of MCS was constructed using the Amesim software,and the parameters of different physiological conditions were simulated to verify the hemodynamic characteristics of MCS,which provided the basis for the design of mechanical structure.(4)The MCS experiments mainly include: system performance,three physiological condition and VAD auxiliary experiment.Amesim was able to capture fundamental characteristic of the MCS but generated difference in terms of transient behaviors.Experimental results showed that the MCS has met most design requirements with some parameters exceeded the desired range.Based on the above work,we completed the design and development of a bi-ventricular MCS with systemic and pulmonary circulations and established an experimental platform for in-vitro VAD testing.