Multi-scale mechanics of traumatic brain injury: predicting axonal strains from head loads
Multi-scale mechanics of traumatic brain injury: predicting axonal strains from head loads
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DOI：
10.1007/s10237-012-0387-6
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发表时间：
2013-01-01
影响因子：
3.5
通讯作者：
Geers, M. G. D.
中科院分区：
文献类型：
--
作者：
Cloots, R. J. H.;van Dommelen, J. A. W.;Geers, M. G. D.
在弥漫性轴索损伤的发展中涉及的长度尺度通常从头部水平（即，机械负载）到细胞水平。易受这种类型损伤的大脑部分主要是脑干和胼胝体，它们是具有高度各向异性定向轴突的区域。在这些部分内，离散的轴突损伤主要发生在轴突由于内含物的存在而不得不偏离其主要路线的地方。本研究的目的是预测轴突应变的结果，在宏观头部水平的机械负荷。为此，采用多尺度有限元方法，其中宏观级头部模型和微观级临界体积单元耦合。结果表明，不考虑轴突取向，轴突应变不能平凡地与组织应变相关，这表明在细胞水平上的异质性在脑损伤和可靠的预测中起着重要的作用。除了多尺度的方法，它表明，一种新的各向异性等效应变措施可以用来评估这些微尺度的影响，从头级模拟。
The length scales involved in the development of diffuse axonal injury typically range from the head level (i.e., mechanical loading) to the cellular level. The parts of the brain that are vulnerable to this type of injury are mainly the brainstem and the corpus callosum, which are regions with highly anisotropically oriented axons. Within these parts, discrete axonal injuries occur mainly where the axons have to deviate from their main course due to the presence of an inclusion. The aim of this study is to predict axonal strains as a result of a mechanical load at the macroscopic head level. For this, a multi-scale finite element approach is adopted, in which a macro-level head model and a micro-level critical volume element are coupled. The results show that the axonal strains cannot be trivially correlated to the tissue strain without taking into account the axonal orientations, which indicates that the heterogeneities at the cellular level play an important role in brain injury and reliable predictions thereof. In addition to the multi-scale approach, it is shown that a novel anisotropic equivalent strain measure can be used to assess these micro-scale effects from head-level simulations only.