Tissue Mechanics Laboratory, Biomedical Engineering Program and Mechanical Engineering Department, University of Connecticut, 207 Bronwell Building, Storrs, CT 06269-3139, USA.
Ann Biomed Eng. 2013 Jan;41(1):142-53. doi: 10.1007/s10439-012-0620-6. Epub 2012 Jul 18.
The objective of this study was to develop a patient-specific finite element (FE) model of a human mitral valve. The geometry of the mitral valve was reconstructed from multi-slice computed tomography (MSCT) scans at middle diastole with distinguishable mitral leaflet thickness, chordal origins, chordal insertion points, and papillary muscle locations. Mitral annulus and papillary muscle dynamic motions were also quantified from MSCT scans and prescribed as boundary conditions for the FE simulation. Material properties of the human mitral leaflet tissues were obtained from biaxial tests and characterized by an anisotropic hyperelastic material model. In vivo dynamic closing of the mitral valve was simulated. The closed shape of the mitral valve output from the simulation was similar to the mitral valve geometry reconstructed from MSCT images at middle systole. Forces from the anterolateral and posteromedial papillary muscle groups at middle systole were 4.51 N and 5.17 N, respectively. The average maximum principal stress of the midsection of the anterior mitral leaflet was approximately 160 kPa at the systolic peak. Results demonstrated that the developed FE model could closely replicate in vivo mitral valve dynamic motion during middle diastole and systole. This model may serve as a basis for utilizing computational simulations to obtain a better understanding of mitral valve mechanics, disease and surgical repair.
本研究旨在开发一种用于人类二尖瓣的特定于患者的有限元（FE）模型。使用多排 CT（MSCT）扫描在舒张中期重建二尖瓣的几何形状，此时可以区分二尖瓣瓣叶的厚度、腱索起源、腱索插入点和乳头肌位置。还从 MSCT 扫描中量化了二尖瓣环和乳头肌的动态运动，并将其规定为 FE 模拟的边界条件。从双轴试验中获得了人类二尖瓣瓣叶组织的材料特性，并通过各向异性超弹性材料模型对其进行了表征。模拟了二尖瓣的体内动态关闭。从模拟中输出的二尖瓣的关闭形状与舒张中期 MSCT 图像重建的二尖瓣几何形状相似。舒张中期前外侧和后内侧乳头肌群的力分别为 4.51N 和 5.17N。前二尖瓣瓣叶中段的平均最大主应力在收缩峰值时约为 160kPa。结果表明，所开发的 FE 模型可以在舒张中期和收缩期紧密复制体内二尖瓣的动态运动。该模型可以作为利用计算模拟来更好地理解二尖瓣力学、疾病和手术修复的基础。
