RELATIONSHIP BETWEEN SOME DESIGN CHARACTERISTICS AND WEAR IN THE BICARBON HEART-VALVE PROSTHESIS

The hinge design of a new bileaflet valve (Bicarbon) is presented in r elation to the long-term durability characteristics Theoretical consid erations supported by experimental findings, lead to the identificatio n of two different wear mechanisms acting in bileaflet valves, ie. imp act and friction wear. impact wear, caused by the collision between th e hinge stops and inflow surface of the leaflet pivots, is the predomi nant phenomenon; it is mostly influenced by the design of the coupling elements. The wear due to friction is significantly less important, g iven a proper kinematic coupling and a thorough washout. These differe nt mechanisms can significantly affect the wear resistance and long-te rm reliability of bileaflet valves; therefore, they have been properly taken into account in designing the new valve model. The safety of th e overall material and design solutions adopted in the Bicarbon valve has been confirmed by extensive accelerated durability tests resulting in no mechanical failure or loss of functionality