Investigation of mechanical heart valve under physiological condition

Abstract

The hemodynamics associated with scale-up models of mechanical bileaflet heart valve prostheses with different geometry arrangements are experimentally studied in vitro with two purpose-developed enlarged heart valve test systems, namely pulsatile flow system and steady flow system. A detailed discussion of the design and performance of the pulsatile flow system is provided. By using experimental techniques, important data on the motion dynamics of bileaflet valves with different hinge positions are obtained and the hydraulic effects on complex valve motion behaviours are also explored through the measurements of transient transvalvular pressure drop and the fluid forces acting on the valve leaflets. Furthermore a new bionics-based bileaflet heart valve design is first proposed in this study and its motion dynamics is experimentally studied. In addition, the flow pattern associated with the opening / closing behaviours of a bileaflet heart valve are studied using laser illuminated flow visualization technique and the flow structure downstream of the bileaflet valve is obtained with the steady flow system through LDA velocity measurement technique.