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 relation to the long-term durability characteristics. Theoretical considerations supported by experimental findings, lead to the identification of two different wear mechanisms acting in bileaflet valves, i.e. impact and friction wear. Impact wear, caused by the collision between the hinge stops and inflow surface of the leaflet pivots, is the predominant phenomenon; it is mostly influenced by the design of the coupling elements. The wear due friction is significantly less important, given a proper kinematic coupling and a thorough washout. These different mechanisms can significantly affect the wear resistance and long-term reliability of bileaflet valves; therefore, they have been properly taken into account in designing the new valve model. The safety of the 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.