| 摘要 |
<p>A heart valve prosthesis (2) of mechanical type and comprising an annular housing (13) wherein the three valves (14) are pivotally mounted about each their respective axes (15) for a symmetrical and synchronous oscillation between an open position (14'') and a closed position (14') is made in such a way that the axes (15) divide each valve (14) into a peripheral part (20) and a central part (21). The axes (15) divide the valves (14) in such a way that the peripheral parts (20) in combination cover an area of the passage (17) of the valve prosthesis (2) which is greater than the area covered by the central parts (21) of the valves (14). Hereby a large central flow is obtained through the central part of the passage (17) together with a large peripheral flow through the peripheral parts of the passage (17). This causes small gradients of velocity to appear when the blood flows through the heart valve prosthesis (2) thereby reducing the risk of thrombi and hemolysis formation.</p> |
