Influence of three mechanical bileaflet prosthetic valve designs on the three-dimensional flow field inside a simulated aorta
Influence of three mechanical bileaflet prosthetic valve designs on the three-dimensional flow field inside a simulated aorta
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DOI：
10.1007/s10047-010-0519-7
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发表时间：
2010-12-01
影响因子：
1.3
通讯作者：
Matsumoto, Akira
中科院分区：
文献类型：
--
作者：
Akutsu, Toshinosuke;Matsumoto, Akira
双叶瓣膜的当前设计（其瓣叶先向外打开）与瓣叶先中心打开的天然瓣膜显著不同。与天然心脏瓣膜相比，这种差异在双叶瓣膜中产生完全不同的流场。在先前的研究中，证明了瓣膜设计极大地影响主动脉流场以及主动脉窦内的循环流量，使用盐水溶液作为工作流体。对阀门可能产生的湍流流场进行了有限的讨论。因此，在该研究的继续中，进行了动态PIV研究，以分析心脏瓣膜设计对主动脉流场的影响，特别是对湍流剖面的影响。本研究还旨在确定测试流体的粘度的影响。在脉动流条件下测试了三种双叶瓣膜-圣犹达医疗用品有限公司（SJM）、On-X和MIRA瓣膜。通过SJM瓣膜中心孔的流量比通过新设计的流量慢。较新的设计倾向于显示通过所有孔的强流。On-X瓣膜产生简单的射流型流动，而具有周向弯曲瓣叶的MIRA瓣膜产生强烈但三维的扩散流动，导致主动脉瓣下游的流场更复杂，湍流更高。临床上更流行的180 A度取向似乎提供比90 A度取向更少的扩散流。发现增加粘度的效果是通过中心孔的流速增加，并且对于所有测试的阀，流场更有组织。
The current design of the bileaflet valve, the leaflets of which open outside first, differs significantly from the natural valve whose leaflets open center first. This difference generates a completely different flow field in the bileaflet valve compared to that in the natural heart valve. In a previous study, it was demonstrated that the valve design greatly affects the aortic flow field as well as the circulatory flow inside sinuses of Valsalva, using saline solution as a working fluid. A limited discussion on the turbulence flow field that could be generated by the valve was provided. In this continuation of that study, therefore, a dynamic PIV study was conducted to analyze the influence of the heart valve design on the aortic flow field, and particularly on the turbulent profile. This study also aimed to determine the influence of the viscosity of the testing fluid. Three bileaflet prostheses-the St. Jude Medical (SJM), the On-X, and the MIRA valves-were tested under pulsatile flow conditions. Flow through the central orifice of the SJM valve was slower than that through the newer designs. The newer designs tend to show strong flow through all orifices. The On-X valve generates simple jet-type flow while the MIRA valve with circumferentially curved leaflets generates a strong but three-dimensionally diffuse flow, resulting in a more complex flow field downstream of the aortic valve with higher turbulence. A 180A degrees orientation that is more popular clinically seems to provide a less diffuse flow than a 90A degrees orientation. The effect of increasing the viscosity was found to be an increase in the flow velocity through the central orifice and a more organized flow field for all of the valves tested.