| 摘要 |
A heart valve prosthesis comprises an occluder ring (10) and two planar leaflets (12, 12) which pivot between a closed position in which they lie at an angle of 25 DEG -60 DEG (preferably 45 DEG ) to the plane containing their pivotal axes (14, 14) and an open position in which they lie at a greater angle (preferably 85 DEG ) to that plane. The leaflets therefore open and close quickly. The pivotal axes (14, 14) are inset a relatively short distance from the outer edges (16, 16) of the leaflets and so do not obstruct the centre region of the valve when open. The occluder ring may be formed from polycrystalline alumina or from titanium, and the leaflets from polycrystalline or single crystal alumina, all of which materials are substantially biologically inert, mechanically strong and wear resistant. |
