A Nonlinear Reduced-Order Model of the Corpus Callosum Under Planar Coronal Excitation
A Nonlinear Reduced-Order Model of the Corpus Callosum Under Planar Coronal Excitation
复制标题
平面冠状激励下胼胝体的非线性降阶模型
DOI：
10.1115/1.4046503
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Vakakis, Alexander F.
中科院分区：
文献类型：
--
作者：
Mojahed, Alireza;Abderezaei, Javid;Kurt, Mehmet;Bergman, Lawrence A.;Vakakis, Alexander F.
创伤性脑损伤（Traumatic brain injury，TBI）是一种复杂的生物力学行为导致的脑组织微结构损伤。最近的研究表明，人类大脑的深层白色物质（WM）区域容易因该区域的应变定位而受损。受这些研究的启发，在本文中，我们提出了一个几何非线性动力学降阶模型（ROM）模拟和研究冠状面激励下的人脑深部WM区域的动力学。在该模型中，大脑半球被建模为通过粘弹性链接连接的集总质量，类似于胼胝体（CC）的几何形状。采用系统识别技术，我们确定的ROM的未知参数，并通过比较其响应对先进的有限元（FE）模型的响应，以确保ROM的准确性。接下来，利用模态分析技术，我们确定的ROM的振动模式之间的能量分布，并得出结论，所展示的FE模型的非线性行为可能主要是由于大脑深部WM区域的特殊几何形状。此外，我们观察到，对于足够高的输入能量，在CC的响应中产生约45 Hz的高频谐波，这又与CC的高频振荡相关联。这种谐波可能潜在地导致CC中的应变局部化。这项工作是了解创伤性损伤期间大脑动力学的一步。
Traumatic brain injury (TBI) is often associated with microstructural tissue damage in the brain, which results from its complex biomechanical behavior. Recent studies have shown that the deep white matter (WM) region of the human brain is susceptible to being damaged due to strain localization in that region. Motivated by these studies, in this paper, we propose a geometrically nonlinear dynamical reduced order model (ROM) to model and study the dynamics of the deep WM region of the human brain under coronal excitation. In this model, the brain hemispheres were modeled as lumped masses connected via viscoelastic links, resembling the geometry of the corpus callosum (CC). Employing system identification techniques, we determined the unknown parameters of the ROM, and ensured the accuracy of the ROM by comparing its response against the response of an advanced finite element (FE) model. Next, utilizing modal analysis techniques, we determined the energy distribution among the governing modes of vibration of the ROM and concluded that the demonstrated nonlinear behavior of the FE model might be predominantly due to the special geometry of the brain deep WM region. Furthermore, we observed that, for sufficiently high input energies, high frequency harmonics at approximately 45 Hz, were generated in the response of the CC, which, in turn, are associated with high-frequency oscillations of the CC. Such harmonics might potentially lead to strain localization in the CC. This work is a step toward understanding the brain dynamics during traumatic injury.