US Naval Research Laboratory, Washington, DC, USA.
Division of Civil, Mechanical and Manufacturing Innovation, NSF, Alexandria, VA, USA.
Int J Numer Method Biomed Eng. 2018 Sep;34(9):e3109. doi: 10.1002/cnm.3109. Epub 2018 Jun 28.
A methodology is introduced to investigate the effect of intersubject head morphological variability on the mechanical response of the brain when subjected to blast overpressure loading. Nonrigid image registration techniques are leveraged to warp a manually segmented template model to an arbitrary number of subjects following a procedure to coarsely segment the subjects in batch. Finite element meshes are autogenerated, and blast analysis is conducted. The template model is initially constructed to enable the full automated implementation and application of the proposed methodology. The application of the proposed approach for an anterior-oriented blast has been demonstrated, and the results reveal that the pressure response in the brain does exhibit some dependence on head morphological variability. While the magnitude of the peak pressure response can vary by more than 30%, its location within the brain is unaffected by head morphological variability. A linear least squares analysis was conducted to demonstrate that the peak magnitude of pressure is uncorrelated with head volume while it is correlated with aspect ratio relating to the amount of exposed surface area to the blast. These features of the pressure response are likely due to the peak pressure occurring during the early stages of stress wave transmission and reflection. As a result, the pressure response due to blast overpressure loading is predominantly loading dependent while morphological variability has a secondary effect.
引入了一种方法来研究在经受爆炸超压载荷时，主体头部形态变异对大脑机械响应的影响。利用非刚性图像配准技术，根据粗分割程序，将手动分割的模板模型变形为任意数量的主体。自动生成有限元网格，并进行爆炸分析。模板模型最初构建为了实现所提出方法的完全自动化实施和应用。已经演示了用于前向爆炸的所提出方法的应用，结果表明大脑中的压力响应确实表现出对头部形态变异的一定依赖性。虽然峰值压力响应的幅度变化可能超过 30%，但其在大脑内的位置不受头部形态变异的影响。进行线性最小二乘分析以证明峰值压力与头部体积无关，而与与爆炸暴露表面积有关的纵横比相关。这些压力响应的特征可能是由于在应力波传播和反射的早期阶段出现峰值压力。因此，爆炸超压载荷引起的压力响应主要取决于载荷，而形态变异具有次要影响。
