Effect of the sinus of valsalva on the closing motion of bileaflet prosthetic heart valves.
Effect of the sinus of valsalva on the closing motion of bileaflet prosthetic heart valves.
复制标题
瓦尔萨尔瓦窦对双叶人工心脏瓣膜关闭运动的影响。
DOI：
10.1046/j.1525-1594.2000.06534-2.x
复制
发表时间：
2000
影响因子：
2.4
通讯作者：
Takeyoshi Dohi
中科院分区：
文献类型：
--
作者：
Yuji Ohta;Yukiaki Kikuta;T. Shimooka;Yoshinori Mitamura;T. Yuhta;Takeyoshi Dohi
传统的双叶人工机械心脏瓣膜在回流时被动关闭。当然，瓣膜具有与闭合相关的问题，例如回流、水锤效应和小叶断裂。另一方面，在天然主动脉瓣的情况下，主动脉窦中的涡流推动瓣叶关闭，并且随着前向流减速，瓣膜比人工瓣膜更早地开始关闭运动。这种关闭机制被认为可以减少阀门关闭时的回流。在这项研究中，我们提出了一种新的双叶机械瓣膜，形状类似于吊桥，原型瓣膜的设计使瓣叶在窦内涡流的帮助下关闭。试验瓣膜由铝合金制成，并将其闭合运动与CarboMedics（CM）瓣膜进行比较。两种瓣膜均由计算机控制的液压模拟循环器驱动，并由高速电荷耦合器件（CCD）相机以648帧/秒的速度拍摄。用个人计算机分析瓣膜运动图像的每一帧，并测量开度角。流速设定为5.0 L/min，系统脉冲为70 bpm，收缩/舒张比为0.3。在室温下使用甘油水作为循环流体，并且使用聚苯乙烯颗粒来可视化流线。用透明硅橡胶制作主动脉窦模型。结果，高速视频分析表明，试验阀比CM阀提前41 ms开始关闭运动，流线分析表明，试验阀具有与自然阀相似的关闭机制，具有涡流效应。试验阀的结构被认为是有效的软关闭，并可以解决与关闭相关的问题。
Conventional bileaflet prosthetic mechanical heart valves close passively with backflow. Naturally, the valve has problems associated with closure, such as backflow, water hammer effect, and fracture of the leaflet. On the other hand, in the case of the natural aortic valve, the vortex flow in the sinus of Valsalva pushes the leaflet to close, and the valve starts the closing motion earlier than the prosthetic valve as the forward flow decelerates. This closing mechanism is thought to decrease backflow at valve closure. In this study, we propose a new bileaflet mechanical valve resembling a drawbridge in shape, and the prototype valve was designed so that the leaflet closes with the help of the vortex flow in the sinus. The test valve was made of aluminum alloy, and its closing motion was compared to that of the CarboMedics (CM) valve. Both valves were driven by a computer controlled hydraulic mock circulator and were photographed at 648 frames/s by a high speed charge-coupled device (CCD) camera. Each frame of the valve motion image was analyzed with a personal computer, and the opening angles were measured. The flow rate was set as 5.0 L/min. The system was pulsed with 70 bpm, and the systolic/diastolic ratio was 0.3. Glycerin water was used as the circulation fluid at room temperature, and polystyrene particles were used to visualize the streamline. The model of the sinus of Valsalva was made of transparent silicone rubber. As a result, high speed video analysis showed that the test valve started the closing motion 41 ms earlier than the CM valve, and streamline analysis showed that the test valve had a closing mechanism similar to the natural one with the effect of vortex flow. The structure of the test valve was thought to be effective for soft closure and could solve problems associated with closure.