Miga M I, Paulsen K D, Hoopes P J, Kennedy F E, Hartov A, Roberts D W
Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA.
J Biomech Eng. 2000 Aug;122(4):354-63. doi: 10.1115/1.1288207.
Current brain deformation models have predominantly reflected solid constitutive relationships generated from empirical ex vivo data and have largely overlooked interstitial hydrodynamic effects. In the context of a technique to update images intraoperatively for image-guided neuronavigation, we have developed and quantified the deformation characteristics of a three-dimensional porous media finite element model of brain deformation in vivo. Results have demonstrated at least 75-85 percent predictive capability, but have also indicated that interstitial hydrodynamics are important. In this paper we investigate interstitial pressure transient behavior in brain tissue when subjected to an acute surgical load consistent with neurosurgical events. Data are presented from three in vivo porcine experiments where subsurface tissue deformation and interhemispheric pressure gradients were measured under conditions of an applied mechanical deformation and then compared to calculations with our three-dimensional brain model. Results demonstrate that porous-media consolidation captures the hydraulic behavior of brain tissue subjected to comparable surgical loads and that the experimental protocol causes minimal trauma to porcine brain tissue. Working values for hydraulic conductivity of white and gray matter are also reported and an assessment of transient pressure gradient effects with respect to deformation is provided.
当前的脑变形模型主要反映了从体外实验数据得出的固体本构关系，并且很大程度上忽略了组织间隙的流体动力学效应。在一种用于术中更新图像以进行图像引导神经导航的技术背景下，我们开发并量化了体内脑变形的三维多孔介质有限元模型的变形特征。结果表明该模型具有至少75%至85%的预测能力，但也表明组织间隙流体动力学很重要。在本文中，我们研究了脑组织在承受与神经外科手术事件一致的急性手术负荷时的组织间隙压力瞬态行为。文中呈现了来自三个猪体内实验的数据，在施加机械变形的条件下测量了皮下组织变形和半球间压力梯度，然后将其与我们的三维脑模型计算结果进行比较。结果表明，多孔介质固结能够捕捉承受类似手术负荷的脑组织的水力行为，并且该实验方案对猪脑组织造成的创伤最小。文中还报告了白质和灰质的水力传导率工作值，并提供了关于变形的瞬态压力梯度效应评估。
