A heart valve has an elliptical occluder mounted for pivoting in an annular heart valve body with a circular passageway between an open position to allow blood flow through the passageway and a closed position to block blood flow. A pair of ears extend from the occluder into a pair of opposed pie-shaped...http://www.google.es/patents/US4326304?utm_source=gb-gplus-sharePatente US4326304 - Heart valve with pivoted occluder
