供应cellscale Brand,BioTester Item#,cellscale BioTester – planar biaxial testing文献 An investigation of regional variations in the biaxial mechanical properties and stress relaxation behaviors of porcine atrioventricular heart valve leaflets猪房室心脏瓣膜双轴力学性能和应力松弛行为的区域变化研究

Abstract

The facilitation of proper blood flow through the heart depends on proper function of heart valve components, and alterations to any component can lead to heart disease or failure. Comprehension of these valvular diseases is reliant on thorough characterization of healthy heart valve structures for use in computational models. Previously, computational models have treated these leaflet structures as a structurally and mechanically homogenous material, which may not be an accurate description of leaflet mechanical response. In this study, we aimed to characterize the mechanics of the heart valve leaflet as a structurally heterogenous material. Specifically, porcine mitral valve and tricuspid valve anterior leaflets were sectioned into six regions and biaxial mechanical tests with various loading ratios and stress-relaxation test were performed on each regional tissue sample. Three main findings from this study were summarized as follows: (i) the central regions of the leaflet had a more anisotropic nature than edge regions, (ii) the mitral valve anterior leaflet was more extensible in regions closer to the annulus, and (iii) there was variance in the stress-relaxation behavior among all six regions, with mitral valve leaflet tissue regions exhibiting a greater decay than the tricuspid valve regions. This study presents a novel investigation of the regional variations in the heart valve biomechanics that has not been comprehensively examined. Our results thus allow for a refinement of computational models for more accurately predicting diseased or surgically-intervened condition, where tissue heterogeneity plays an essential role in the heart valve function.

概述：
适当的血液流经心脏的便利性取决于心脏瓣膜组件的正常功能，任何组件的改动都可能导致心脏病或衰竭。对这些瓣膜疾病的理解取决于用于计算模型的健康心脏瓣膜结构的面表征。以前，计算模型已将这些小叶结构视为结构和机械上均质的材料，这可能不是小叶机械响应的准确描述。在这项研究中，我们旨在将心脏瓣膜小叶的力学特性表征为结构异质材料。具体而言，将猪二尖瓣和三尖瓣前小叶切成六个区域，并对每个区域组织样本进行各种负荷比的双轴力学测试和应力松弛测试。这项研究的三个主要发现总结如下：（i）小叶的中央区域比边缘区域具有更多的各向异性，（ii）二尖瓣前小叶在更靠近环面的区域更可扩展，并且（iii ）在all六个区域中，应力松弛行为均存在差异，二尖瓣小叶组织区域表现出比三尖瓣区域更大的衰减。这项研究提出了尚未面检查的心脏瓣膜生物力学区域变化的新颖调查。因此，我们的结果允许完善计算模型，以便更准确地预测患病或手术干预的情况，其中组织异质性在心脏瓣膜功能中起着至关重要的作用。