Prosthetic heart valve

摘要

Heart valves are shown which utilize pivot arrangements that create prompt response to flow reversal and minimize resistance to blood flow in the open position. Illustrated are valves having a pair of identical leaflets that can assume an orientation in the fully open position near maximum blood flow rate that is precisely parallel to the centerline of the passageway. The ability of the leaflets to assume a precisely parallel or low energy position in the bloodstream reduces pressure drop across the valve and results in improved flow characteristics. A camming action adjacent the upstream edges of the leaflets in combination with interengagement at downstream locations on the valve body, spaced from the locations where the camming action with said upstream edges occurs, positively guide the leaflets to assure effective closing movement regardless of momentary deviations in the dynamics of the reverse flow of blood through the valve. More particularly, slight closing movement pivoting, following assumption of such a parallel orientation, is effected by designing the interengagement so that the leaflets shift slightly downstream from the precisely parallel orientation when the blood flow slows prior to reversing and simultaneously rotate slightly toward their closed position orientation.