Impact of superhydrophobicity on the fluid dynamics of a bileaflet mechanical heart valve
Impact of superhydrophobicity on the fluid dynamics of a bileaflet mechanical heart valve
复制标题
超疏水性对双叶机械心脏瓣膜流体动力学的影响
DOI：
10.1016/j.jmbbm.2020.103895
复制
发表时间：
2020
影响因子：
3.9
通讯作者：
Dasi, Lakshmi Prasad
中科院分区：
文献类型：
--
作者：
Hatoum, Hoda;Vallabhuneni, Sravanthi;Kota, Arun Kumar;Bark, David L.;Popat, Ketul C.;Dasi, Lakshmi Prasad
目的研究超疏水涂层对双小管机械瓣膜血流动力学和湍流特性的影响，以评估血液损伤潜力。方法在生理压力和生理流量条件下，在脉冲复制仪上对两个3D打印的双肢机械瓣膜进行血流动力学测试。其中一个阀门的叶片被喷涂了超疏水涂层。进行粒子图像测速。计算了压力梯度（PG）、有效孔口面积（EOA）、雷诺剪应力（RSS）和瞬时粘性剪应力（VSS）。结果(a)无SH涂层时，PG值为14.53±0.7 mmHg， EOA值为1.44±0.06 cm2。包覆后，PG值为15.21±1.7 mmHg， EOA值为1.39±0.07 cm2；(b)在收缩高峰期，有SH包覆（110Pa）的相对过饱和度（RSS）大于没有SH包覆（40pa）的相对过饱和度（RSS），且更有可能在小叶的直接尾迹中产生较高的相对过饱和度；(c)经SH涂层获得的瞬时VSS的大小范围略大于未经SH涂层获得的瞬时VSS （7.0 Pa vs 5.0 Pa）。结论血小板损伤与雷诺剪应力和瞬时粘性剪应力有关，SH涂层并未导致其降低。虽然已知SH涂层可以改善表面性能，如减少血小板或凝块粘附，但滑移条件的放松并不一定能改善双叶机械阀设计的整体血流动力学性能。
ObjectiveThe objective of this study is to evaluate the impact of superhydrophobic coating on the hemodynamics and turbulence characteristics of a bileaflet mechanical valve in the context of evaluating blood damage potential.MethodsTwo 3D printed bileaflet mechanical valves were hemodynamically tested in a pulse duplicator under physiological pressure and flow conditions. The leaflets of one of the two valves were sprayed with a superhydrophobic coating. Particle Image Velocimetry was performed. Pressure gradients (PG), effective orifice areas (EOA), Reynolds shear stresses (RSS) and instantaneous viscous shear stresses (VSS) were calculated.Results(a) Without SH coating, the PG was found to be 14.53 ± 0.7 mmHg and EOA 1.44 ± 0.06 cm2. With coating, the PG obtained was 15.21 ± 1.7 mmHg and EOA 1.39 ± 0.07 cm2; (b) during peak systole, the magnitude of RSS with SH coating (110Pa) exceeded that obtained without SH coating (40 Pa) with higher probabilities to develop higher RSS in the immediate wake of the leaflet; (c) The magnitudes range of instantaneous VSS obtained with SH coating were slightly larger than those obtained without SH coating (7.0 Pa versus 5.0 Pa).ConclusionWith Reynolds Shear Stresses and instantaneous Viscous Shear Stresses being correlated with platelet damage, SH coating did not lead to their decrease. While SH coating is known to improve surface properties such as reduced platelet or clot adhesion, the relaxation of the slip condition does not necessarily improve overall hemodynamic performance for the bileaflet mechanical valve design.