Zamir Evan A, Taber Larry A
Department of Biomedical Engineering, Washington University, St. Louis, MO 63130, USA.
J Biomech Eng. 2004 Dec;126(6):823-30. doi: 10.1115/1.1824129.
During the morphogenetic process of cardiac looping, the initially straight cardiac tube bends and twists into a curved tube. The biophysical mechanisms that drive looping remain unknown, but the process clearly involves mechanical forces. Hence, it is important to determine mechanical properties of the early heart, which is a muscle-wrapped tube consisting primarily of a thin outer layer of myocardium surrounding a thick extracellular matrix compartment known as cardiac jelly. In this work, we used microindentation experiments and finite element modeling, combined with an inverse computational method, to determine constitutive relations for the myocardium and cardiac jelly at the outer curvature of stage 12 chick hearts. Material coefficients for exponential strain-energy density functions were found by fitting force-displacement and surface displacement data near the indenter Residual stress in the myocardium also was estimated. These results should be useful for computational models of the looping heart.
在心脏成环的形态发生过程中，最初笔直的心脏管会弯曲并扭曲成一个弯曲的管子。驱动成环的生物物理机制尚不清楚，但该过程显然涉及机械力。因此，确定早期心脏的力学特性很重要，早期心脏是一个被肌肉包裹的管子，主要由围绕着称为心胶的厚细胞外基质隔室的薄外层心肌组成。在这项工作中，我们使用微压痕实验和有限元建模，并结合逆计算方法，来确定第12阶段鸡心脏外曲率处心肌和心胶的本构关系。通过拟合压头附近的力-位移和表面位移数据，找到了指数应变能密度函数的材料系数。还估计了心肌中的残余应力。这些结果应该对成环心脏的计算模型有用。
