Department of Structural Engineering, Norwegian University of Science and Technology, Trondheim, Norway.
J Mech Behav Biomed Mater. 2010 Feb;3(2):167-77. doi: 10.1016/j.jmbbm.2009.05.004. Epub 2009 Sep 6.
Biomechanical data and related constitutive modelling of the mitral apparatus served as a basis for finite element analyses to better understand the physiology of mitral valves in health and disease. Human anterior and posterior leaflets and chordae tendinae from an elderly heart showing no disease and a hypertrophic obstructive cardiomyopathic heart (HOCM) were mechanically tested by means of uniaxial cyclic extension tests under quasi-static conditions. Experimental data for the leaflets and the chordae tendinae showed highly nonlinear mechanical behaviours and the leaflets were anisotropic. The mitral valve from the HOCM heart exhibited a significantly softer behaviour than the valve from the healthy one. A comparison with porcine data was included because many previous mitral modelling studies have been based on porcine data. Some differences in mechanical response were observed. Material parameters for hyperelastic, transversely isotropic constitutive laws were determined. The experimental data and the related model parameters were used in two finite element studies to investigate the effects of the material properties on the mitral valve response during systole. The analyses showed that during systole the mitral valve from the HOCM heart bulged into the left atrium by taking on the shape of a balloon, whereas the anterior leaflet of the healthy valve remained in the left ventricle.
二尖瓣装置的生物力学数据和相关本构模型为有限元分析提供了基础，以便更好地了解健康和患病二尖瓣的生理学。通过准静态单向循环拉伸试验，对来自无病变老年心脏和肥厚型梗阻性心肌病（HOCM）心脏的前后二尖瓣叶和腱索进行力学测试。实验数据表明，瓣叶和腱索具有高度非线性的力学行为，且瓣叶具有各向异性。HOCM 心脏的二尖瓣表现出明显比健康心脏的二尖瓣更柔软的行为。还包括与猪的数据进行比较，因为许多以前的二尖瓣建模研究都是基于猪的数据。观察到在力学响应方面存在一些差异。确定了超弹性各向同性本构定律的材料参数。实验数据和相关模型参数用于两项有限元研究中，以研究材料特性对收缩期二尖瓣响应的影响。分析表明，在收缩期，HOCM 心脏的二尖瓣呈气球状凸入左心房，而健康瓣膜的前瓣叶仍留在左心室。
