Micromechanics of the Aortic Valve:Durability Testing

超出所提供的空间。随着导管植入（Cl）瓣膜的出现，生物人工心脏瓣膜领域又回到了原点。在70年代和80年代初，阀门行业还很年轻，很幼稚。数百名外科医生和工程师研究了几十种不同的瓣膜设计。许多早期的设计都失败了，大多数都被拒绝了，随着时间的推移和临床经验的积累，该行业最终采用了无支架和支架安装的猪异种移植物和牛心包瓣膜。然而，这种有限的生物假体选择却为心脏瓣膜接受者带来了巨大的好处。在过去的15年里，患者使用当前一代的生物假体瓣膜获得了出色的性能和安全性，这与早期假体瓣膜设计缺陷导致早期瓣膜衰竭和患者死亡的情况截然不同。随着Cl瓣膜的出现，我们又回到了在临床试验中对患者进行不成熟和可能存在缺陷的设备测试的日子。这是不需要发生的。我们可以从过去的经验中吸取很多教训，并将其应用于导管植入术瓣膜的改进。我们建议建立基于心包组织的Cl阀的功能精确的流固耦合有限元分析（FSI）模型，并对一系列设计迭代进行前瞻性测试。具体来说，我们将(i)使用我们现有的FEA技术模拟通用Cl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（DPIV）表征流体动力阀测试仪内的流体动力学环境，以便我们可以（iii）根据实际功能数据验证简化Cl阀的FSI模型。这将使我们能够在建模环境中模拟一系列设计、制造和部署变化，这是现实的，代表了真正的导管可植入瓣膜。计算建模方法在大多数生物医学设备中的应用有限，因为失效机制尚不清楚。然而，计算机建模在将已知的失效机制应用于全新的阀门设计方面有很大的好处。新一波Cl阀急需设计审查和分析，因此是计算建模研究的沃土。传统生物假体瓣膜的经验教训可以应用于Cl瓣膜，改进其设计和性能，从而减少临床试验中的并发症。网站性能 ======================================== 节结束 ===========================================

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===========================================