Simulation And In-vitro Study Of Intro-ascending-aortic Balloon Pump

The heart plays a vital role in the cardiovascular system as the driving force of blood circulation throughout the body.Heart failure,as the end phase of the development of all cardiovascular diseases,refers to the blood which returns from the veins cannot be excluded the heart which leads to the artery infusion is insufficient due to the dysfunction of the contraction and diastolic ability of the heart.Intro-aortic balloon pump(IABP)is one of the most common heart assisting devices in clinic.What make it works is by planting a appropriate balloon into the descending aorta,the balloon inflates just before systole and deflates just after the diastole which could decrease the afterload and improve the ratio of oxygen supply and demand.Finally playing a role in protecting the myocardium.Base on the traditional intro-aortic balloon pump,this paper issued a ascending intro-aortic balloon pump by changing the working position of the balloon in the aorta.The balloon was put closer to the aortic root by implanting the balloon into the ascending aorta.The assisting effectiveness of the balloon at different location in the aorta was quantitatively studied in vitro experiment in order to evacuate the effective of the ascending balloon.And this paper used the equivalent simulator of circulatory system to study the impact of the ascending balloon to the coronary volume.This paper is divided into two main parts as follows:1.A in vitro experimental platform was built with a adult aorta model,it mainly includes left atrium,left ventricle,aorta model,mitral valve,aortic valve,compliance chamber and left heart driving device used to provide the circulatory power to the platform.With the coordination of the left heart driving device and the pipe system,the platform was capable of simulating the physiological left heart circulation,what's more,it can run as heart failure.In this paper,the platform was adjusted to simulate level-I heart failure and level-II heart failure,and the balloon pump was studied in these two states separately in order to study the effect of the balloon pump at different positions in the main aorta.Results showed at level I HF,the endocardial viability ratio(EVR)increased by 12.7% when the IABP was at descending aorta,and the EVR increased by 19.0% when the IABP was at ascending aorta,at level II HF,the EVR increased by 13.9% when the IABP was at descending aorta,and the EVR increased by31.2% when the IABP was at ascending aorta;moreover,at level I HF,the EVR increased by5.6% when the IABP was at ascending aorta compared to the IABP at descending aorta,the EVR increased by 15.1% when the IABP was at ascending aorta compared to the IABP at descending aorta.2.The equivalent electronic model to physiological left heart circulation was built by using electro-fluid equivalency,this model consisted of coronary artery model,and the balloon pump model was added into it.The hemodynamic changes after the ascending balloon pump assisting were studied under heart failure,especially the change in coronary flowrate.The simulation result showed that the ascending balloon pump can reduce the afterload and improve the ratio of myocardial oxygen supply,particularly the perfusion of coronary artery increased.