Mechanical Engineering and Materials Science, Washington University in St. Louis, MO, United States.
Center for Neuroscience and Regenerative Medicine, Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States.
J Biomech. 2021 Apr 15;119:110259. doi: 10.1016/j.jbiomech.2021.110259. Epub 2021 Feb 10.
Natural modes and frequencies of three-dimensional (3D) deformation of the human brain were identified from in vivo tagged magnetic resonance images (MRI) acquired dynamically during transient mild acceleration of the head. Twenty 3D strain fields, estimated from tagged MRI image volumes in 19 adult subjects, were analyzed using dynamic mode decomposition (DMD). These strain fields represented dynamic, 3D brain deformations during constrained head accelerations, either involving rotation about the vertical axis of the neck or neck extension. DMD results reveal fundamental oscillatory modes of deformation at damped frequencies near 7 Hz (in neck rotation) and 11 Hz (in neck extension). Modes at these frequencies were found consistently among all subjects. These characteristic features of 3D human brain deformation are important for understanding the response of the brain in head impacts and provide valuable quantitative criteria for the evaluation and use of computer models of brain mechanics.
从动态采集的人体头部瞬时轻度加速过程中的标记磁共振图像（MRI）中识别出三维（3D）大脑变形的固有模态和固有频率。使用动态模式分解（DMD）分析了从 19 名成年受检者的标记 MRI 图像体积中估算的 20 个 3D 应变场。这些应变场代表了在头部受限加速过程中动态的、3D 的大脑变形，包括颈部绕垂直轴的旋转或颈部伸展。DMD 结果揭示了在颈部旋转时约 7 Hz（在颈部旋转时）和 11 Hz（在颈部伸展时）的阻尼频率附近的基本振荡变形模式。在所有受检者中都发现了这些频率的模式。这些 3D 人脑变形的特征对于理解头部撞击时大脑的反应非常重要，并为脑力学计算机模型的评估和使用提供了有价值的定量标准。
