Mechanical heart valve prosthesis

Abstract

An improved artificial mechanical heart valve prosthesis having an improved leaflet hinge mechanism which improves washing of the hinge recess, reduces leaflet closing impact force and decreases noise and wear. A generally annular valve body having an annular interior surface extending between an inflow rim and an outflow rim thereof defines an annular orifice therethrough. A pair of leaflets are supported on said annular valve body for alternately blocking blood flow in an inflow direction when seated against the annular interior side wall in a closed position and then allowing the flow of blood through said annular orifice in a predetermined blood outflow direction when rotated into an open position. Each leaflet is supported for pivotal movement by a pair of hinge mechanisms comprising a pair of convexly extending leaflet ears that each fit within a hinge recess formed in parallel planar surfaces of the annular interior side wall. A relatively shallow inflow or entrance ramp is achieved in an inflow portion of the hinge recess employing an inwardly curved inflow transition surface from the planar surface at the arcuate inflow end edge into the inflow portion of the leaflet ear bearing surface. An open outflow or exit ramp is achieved employing a curved outflow transition surface of the leaflet ear bearing surface in the outflow portion of the hinge recess meeting the arcuate outflow end edge which itself joins a recessed outflow flat in the planar surface that the hinge recess is formed in. The hinge recess side walls are shaped to minimize blood cell damage. Inflow rim transition zones deflect blood flow centrally through the annular orifice. Planar inflow chamfers extending between the planar surfaces and the inflow rim deflect blood compomnents away from the hinge recesses.