标题： 结合准静态和高频实验对脑组织的粘弹性特性进行表征 显示英文标题

标题： Combining quasi-static and high frequency experiments for the viscoelastic characterization of brain tissue

摘要： 脑组织的力学模型是模拟神经外科手术、疾病进展或脑发育的有益工具。 然而，这种模型的准确性和预测能力依赖于对组织力学行为的精确实验表征。 这种表征仍受到文献中不一致或矛盾的实验响应的限制，尤其是在不同时间和长度尺度上进行测量时。 尽管脑组织在以前的研究中已被广泛研究，但来自不同尺度的实验结果的结合却受到有限的关注。 在本研究中，我们将不同时间尺度下获得的猪脑组织体外力学响应结合到一个力学模型中。 我们通过多模式大应变流变仪测量在准静态领域中研究了三个不同脑区的力学行为，并通过磁共振弹性成像（MRE）在高频下进行研究。 从两种实验技术中获得的力学参数的比较分析显示，在两个领域中粘弹性行为存在一致的区域变化。 然而，力学行为从准静态和低频域中的较高弹性转变为高频域中的主导粘性。 基于准静态和高频行为，我们校准了一个分数阶Kelvin-Voigt模型，并因此在一个单一的力学模型中统一了两种响应，以获得对组织力学行为的全面表征。 显示英文摘要

摘要： Mechanical models of brain tissue are a beneficial tool to simulate neurosurgical interventions, disease progression, or brain development. However, the accuracy and predictive capacity of such a model relies on a precise experimental characterization of the tissue's mechanical behavior. Such a characterization is yet limited by inconsistent or contradictory experimental responses reported in the literature, particularly when measurements are performed in different time or length scales. Although brain tissue has been extensively investigated in previous studies, the combination of experimental findings from different scales has received limited attention. In this study, we combine ex vivo mechanical responses of porcine brain tissue obtained at different time scales in a mechanical model. We investigated the mechanical behavior of three different brain regions in the quasi-static domain with multi-modal large strain rheometer measurements and at high frequencies with magnetic resonance elastography (MRE). A comparative analysis of the mechanical parameters obtained from both experimental techniques demonstrated consistent regional variations in the viscoelastic behavior across the two domains. However, the mechanical behavior changes from a higher elasticity in the quasi-static and low frequency domain to a dominating viscosity at high frequencies. Based on the quasi-static and the high frequency behavior, we calibrated a fractional Kelvin-Voigt model and consequently unified the two responses in a single mechanical model to obtain a comprehensive characterization of the tissue's mechanical behavior.