Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science and Great Ormond Street Hospital for Children, Great Ormond Street, London, WC1N 3JH, UK.
Ann Biomed Eng. 2012 Dec;40(12):2663-73. doi: 10.1007/s10439-012-0617-1. Epub 2012 Jul 21.
Finite element (FE) modelling can be a very resourceful tool in the field of cardiovascular devices. To ensure result reliability, FE models must be validated experimentally against physical data. Their clinical application (e.g., patients' suitability, morphological evaluation) also requires fast simulation process and access to results, while engineering applications need highly accurate results. This study shows how FE models with different mesh discretisations can suit clinical and engineering requirements for studying a novel device designed for percutaneous valve implantation. Following sensitivity analysis and experimental characterisation of the materials, the stent-graft was first studied in a simplified geometry (i.e., compliant cylinder) and validated against in vitro data, and then in a patient-specific implantation site (i.e., distensible right ventricular outflow tract). Different meshing strategies using solid, beam and shell elements were tested. Results showed excellent agreement between computational and experimental data in the simplified implantation site. Beam elements were found to be convenient for clinical applications, providing reliable results in less than one hour in a patient-specific anatomical model. Solid elements remain the FE choice for engineering applications, albeit more computationally expensive (>100 times). This work also showed how information on device mechanical behaviour differs when acquired in a simplified model as opposed to a patient-specific model.
有限元（FE）建模在心血管设备领域是一种非常有用的工具。为了确保结果的可靠性，FE 模型必须通过物理数据与实验进行验证。其临床应用（例如患者的适用性、形态评估）还需要快速的模拟过程和结果访问，而工程应用则需要高度准确的结果。本研究展示了不同网格离散化的 FE 模型如何满足研究用于经皮瓣膜植入的新型装置的临床和工程要求。在对材料进行敏感性分析和实验特性描述后，支架-移植物首先在简化的几何形状（即顺应性圆柱）中进行研究，并与体外数据进行验证，然后在患者特定的植入部位（即可扩张的右心室流出道）中进行研究。使用实体、梁和壳单元的不同网格策略进行了测试。结果表明，在简化的植入部位，计算数据与实验数据之间具有极好的一致性。梁单元被发现适用于临床应用，在患者特定的解剖模型中不到一个小时即可提供可靠的结果。实体单元仍然是工程应用的 FE 选择，尽管计算成本更高（>100 倍）。这项工作还展示了当在简化模型与患者特定模型中获取设备机械性能信息时，信息有何不同。
