Development and validation of a constitutive growth model for brain tissue characterising brain alterations in space and time

开发和验证脑组织的本构生长模型，表征大脑在空间和时间上的变化

• 批准号: 404568779
• 负责人: Professor Dr.-Ing. Markus Böl
• 金额: --
• 依托单位: Institut für Mechanik und Adaptronik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/404568779?language=en
• 关键词: Development; validation; constitutive; growth; model

The brain, as a part of the central nervous system is probably the most complex biological system, which undergoes significant changes, especially during its growth phase. Because of these complexities, both, at the macroscopic and microscopic level, and the associated difficulties in experimental sampling, there are insufficient experimental investigations. In addition, age-related, mechanical investigations on brain tissue, which were also carried out spatially resolved, are extremely rare. However, such experiments are essential in order to better understand the mechanical properties and functions of the brain during growth and to be able to develop and validate numerical models. The performance of such models in terms of predictive accuracy depends particularly on the quality of the identified material parameters.The objective of this research project is the development and validation of a constitutive growth model for brain tissue that characterises alterations of the mammalian brain both, in space and time. This goal will be achieved in four steps through a close interplay of experiment, modelling, and simulation. Experiments will be performed on porcine brain tissue, displaying similar microstructural and mechanical properties as the human brain. An essential requirement for the modelling is the method development (I) to perform appropriate tissue-level experiments. Since grey and white matter tissue will be sampled individually, the tissue specimens are relatively small. This implies that for the axial, biaxial, and triaxial experiments planned within this project, micromechanical measurement setups under a microscope have to be developed, constructed, and verified. These measurements will allow us to accurately characterise the axial, biaxial, and triaxial behaviour of brain tissue (II). To examine the influence of neurodevelopment on the mechanical properties, brain samples will be collected at different ages. In a third step, the microstructure as well as the macroscopic geometry of the brain will be determined by means of immunohistological investigations (III). The resulting cell density, myelin content, and tissue microstructure will directly inform the model development and validation (IV).

作为中枢神经系统的一部分，大脑可能是最复杂的生物系统，它发生了重大变化，尤其是在其生长阶段。由于这些复杂性，在宏观和显微镜水平上都存在，以及实验抽样的相关困难，实验研究不足。此外，对脑组织的年龄相关的机械研究也非常罕见。但是，这样的实验对于更好地了解生长过程中大脑的机械性能和功能至关重要，并能够开发和验证数值模型。此类模型在预测精度方面的性能特别取决于已确定的材料参数的质量。该研究项目的目的是对脑组织的构型增长模型的开发和验证，该模型表征了哺乳动物大脑在空间和时间上的变化。通过实验，建模和仿真的紧密相互作用，将在四个步骤中实现此目标。实验将在猪脑组织上进行，显示出与人脑相似的微结构和机械性能。建模的基本要求是进行适当的组织级实验的方法开发（i）。由于将单独采样灰质和白质组织，因此组织样品相对较小。这意味着，对于计划在该项目中计划的轴向，双轴和三轴实验，必须开发，构造和验证显微镜下的微机械测量设置。这些测量结果将使我们能够准确地表征脑组织的轴向，双轴和三轴行为（II）。为了检查神经发育对机械性能的影响，将在不同年龄收集大脑样本。在第三步中，将通过免疫组织学研究（III）确定微观结构以及大脑的宏观几何形状。所得的细胞密度，髓磷脂含量和组织微观结构将直接告知模型开发和验证（IV）。