Regional mechanics of the heart is vital in the development of accurate computational models for the pursuit of relevant therapies. Challenges related to heart dysfunctioning are the most important sources of mortality in the world. For example, myocardial infarction (MI) is the foremost killer in sub-Saharan African countries. Mechanical characterisation plays an important role in achieving accurate material behaviour. Material behaviour and constitutive modelling are essential for accurate development of computational models. The biaxial test data was utilised to generated Fung constitutive model material parameters of specific region of the pig myocardium. Also, Choi-Vito constitutive model material parameters were also determined in various myocardia regions. In most cases previously, the mechanical properties of the heart myocardium were assumed to be homogeneous. Most of the computational models developed have assumed that the all three heart regions exhibit similar mechanical properties. Hence, the main objective of this paper is to determine the mechanical material properties of healthy porcine myocardium in three regions, namely left ventricle (LV), mid-wall/interventricular septum (MDW) and right ventricle (RV). The biomechanical properties of the pig heart RV, LV and MDW were characterised using biaxial testing. The biaxial tests show the pig heart myocardium behaves non-linearly, heterogeneously and anisotropically. In this study, it was shown that RV, LV and MDW may exhibit slightly different mechanical properties. Material parameters of two selected constitutive models here may be helpful in regional tissue mechanics, especially for the understanding of various heart diseases and development of new therapies.

中文翻译：

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被动式猪心脏双轴力学性能研究：区域差异的材料表征和分类

心脏的区域力学对于追求相关疗法的精确计算模型的发展至关重要。与心脏功能障碍有关的挑战是世界上最重要的死亡率来源。例如，心肌梗塞（MI）是撒哈拉以南非洲国家的头号杀手。机械表征在实现准确的材料性能方面起着重要作用。材料行为和本构模型对于精确开发计算模型至关重要。利用双轴测试数据生成猪心肌特定区域的Fung本构模型材料参数。此外，还确定了各个心肌区域的Choi-Vito本构模型材料参数。在大多数情况下，心脏心肌的机械性能被认为是均匀的。开发的大多数计算模型都假设所有三个心脏区域都表现出相似的机械性能。因此，本文的主要目的是确定健康猪心肌的三个部位的机械材料特性，即左心室（LV），中壁/室间隔（MDW）和右心室（RV）。使用双轴测试表征猪心脏RV，LV和MDW的生物力学性能。双轴测试显示猪心脏心肌表现出非线性，异质性和各向异性。在这项研究中，表明RV，LV和MDW可能表现出略微不同的机械性能。这里选择的两个本构模型的材料参数可能对区域组织力学有帮助，