Mechanical heart valve prostheses are based on older designs without changes during the last 40 years. Today, there is an unmet need for less thrombogenic mechanical prostheses. Analysis of the relationship between flow characteristics and thromboembolic complications is possible using numerical and biomolecular flow studies that have shown that the reverse rather than the forward flow is responsible for local platelet activation and thrombosis. After peak flow, leaflets experience flow deceleration and the leaflets are still widely open when the flow becomes zero. The closure of the valve starts with the onset of reverse flow. Therefore, the valve closes extremely fast with most of the leaflet traveling angle occurring in <10 ms with excessively high reverse flow velocities. The pivoting spaces, so-called "Hot Spots" should be eliminated to prevent pathologic shear stress that result in thrombosis. A novel tri-leaflet valve combines favorable hemodynamics with the durability of mechanical heart valve. This valve closes within 60 ms, much slower than bi-leaflet valves and similar to the closing mode of a tissue valve. Micro-particle image velocimetry did not show critical regions of flow stagnation and zones of excessive shear in the pivoting region suggesting low potential for thrombogenic events that should allow to avoid long-term anticoagulation.

中文翻译：

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双瓣机械性心脏假体的非生理性闭合需要新的三瓣瓣膜设计。

机械心脏瓣膜假体是基于较旧的设计，在过去40年中没有任何变化。如今，对于未形成血栓的机械假体的需求尚未得到满足。使用数值和生物分子流研究可以分析血流特征与血栓栓塞并发症之间的关系，这些研究表明，逆流而不是正向流动是局部血小板活化和血栓形成的原因。流量达到峰值后，小叶会经历流量减速，当流量变为零时，小叶仍会张开。阀门的关闭从逆流开始开始。因此，瓣膜非常快地关闭，大多数瓣叶行进角在<10 ms内出现，并且逆流速度过高。枢纽空间，即所谓的“热点” 应消除以防止导致血栓形成的病理切应力。新型三叶瓣膜结合了良好的血液动力学特性和机械心脏瓣膜的耐用性。该瓣膜在60毫秒内关闭，比双叶瓣膜慢得多，并且类似于组织瓣膜的关闭模式。微粒图像测速仪未显示流动停滞的关键区域和枢轴区域中的过度剪切区域，这表明血栓形成事件的可能性较低，应避免长期抗凝。