Micromechanics of the Aortic Valve:Durability Testing

超出提供的空间。随着可植入导管瓣膜的出现，生物瓣膜领域又回到了原点。在70年代的S和80年代初的S，阀门行业还很年轻，还很年轻。数百名外科医生和工程师玩弄了数十种不同的瓣膜设计。这些早期的设计很多都失败了，大多数都被拒绝了，随着时间的推移和临床经验的推移，该行业解决了无支架和支架安装的猪异种心脏瓣膜和牛心包瓣膜。然而，这种有限的生物假体选择对心脏瓣膜接受者来说是一个巨大的好处。在过去的15年里，患者使用当前一代生物假体瓣膜享受到了卓越的性能和安全性-这与假体瓣膜的萌芽时期截然不同，在初期，有缺陷的设计会导致瓣膜早期失效和患者死亡。随着氯气阀的出现，我们回到了在临床试验期间在患者身上测试不成熟和潜在缺陷设备的日子。这种情况不一定会发生。我们可以从过去的教训中学到很多东西，并将其应用于导管可植入瓣膜的改进。我们建议开发功能精确的心包组织氯瓣膜的流体-结构相互作用(FSI)有限元分析(FEA)模型，并前瞻性地测试一系列设计迭代。具体地说，我们将(I)使用我们现有的有限元技术模拟通用氯气阀的制造过程，复制其组件的内部预应力，(Ii)使用数字粒子图像测速仪(DPIV)来表征流体动力阀测试仪中的流体动力学环境，以便我们能够(Iii)根据实际功能数据验证简化氯气阀的FSI模型。这将使我们能够(Iv)在模拟环境中模拟一系列设计、制造和部署的变化，该环境逼真且代表真实的导管可植入瓣膜。由于失效机制不为人所知，计算建模方法在大多数生物医学设备中的应用有限。然而，在将已知的故障机制应用于全新的阀门设计中，计算机建模可以有很大的好处。新一轮的氯气阀迫切需要设计审查和分析，因此为计算模型研究提供了肥沃的土壤。传统生物瓣膜的经验教训可以应用于氯瓣膜，改进其设计和性能，从而减少临床试验中的并发症。表演网站========================================Section End===========================================

EXCEED THE SPACE PROVIDED. With the emergence of Catheter-lmplantable (Cl) valves, the bioprosthetic heart valve field has come full circle. In the 70's and early 80's, the valve industry was young and na'i've. Hundreds of surgeons and engineers toyed with dozens of different valve designs. Many of these early designs failed, most were rejected, and with the passage of time and clinical experience, the industry settled with stentless and stent- mounted porcine xenograft and bovine pericardial valves. This limited choice of bioprostheses, however, turned out to be a great benefit for heart valve recipients. For the past 15 years, patients have enjoyed outstanding performance and safety with current generation bioprosthetic valves - a very different scenario from the nascent period of prosthetic valves in which flawed designs lead to early valve failure and patient death. With the emergence of Cl valves, we have returned to the days when immature and potentially flawed devices are tested on patients during clinical trials. This need not happen. Much can be learned from the lessons of the past and applied to the refinement of Catheter-lmplantable valves. We propose to develop functionally accurate fluid-structure interaction (FSI) finite element analysis (FEA) models of pericardial tissue-based Cl valves and prospectively test a series of design iterations. Specifically, we will (i) simulate the fabrication process of a generic Cl valve using our existing FEA technology, duplicating the internal pre-stress of its components, (ii) characterize the fluid dynamics environment within a hydrodynamic valve tester using digital particle image velocimetry (DPIV) so that we can (iii) validate the FSI model of a simplified Cl valve against real functional data. This will enable us to then (iv) simulate a series of design, manufacture and deployment variations in a modeling environment that is realistic and representative of a real Catheter-lmplantable valve. Computational modelling approaches have had limited use in most biomedical devices because failure mechanisms are not well known. Computer modeling, however, can have great benefit in the application of known failure mechanisms to completely new valve designs. The new wave of Cl valves is in dire need of design review and analysis, and hence fertile ground for computational modeling studies. The lessons learned with conventional bioprosthetic valves can be applied to Cl valves, their design and performance improved, and complications in clinical trials thus reduced. PERFORMANCE SITE ========================================Section End===========================================