Wake Forest University School of Medicine, Winston-Salem, NC, USA.
Ann Biomed Eng. 2010 May;38(5):1789-800. doi: 10.1007/s10439-010-9957-x. Epub 2010 Feb 23.
Mechanistic modeling approaches are important for understanding how fluid and solid components of the liver interact during impact trauma. This study uses poroviscoelasticity (PVE) theory to simulate liver biomechanical response in unconfined compression stress relaxation experiments, for variable ramp strain rates ranging from 0.001 to 0.1 s(-1). Specimens included 17 ex vivo porcine liver samples tested in a humidified temperature-controlled chamber. Liver response was modeled using ABAQUS, and best-fit parameters were determined using non-linear least-squares algorithms. The PVE model was able to capture the behavior of porcine liver in unconfined compression, with regression analyses for the ramp phase demonstrating high correlation between model and experiment (R(2) > 0.993, slope > 0.833, p < 0.05). The advantage of PVE modeling over traditional viscoelastic modeling is the ability to examine interstitial fluid pressure as a contributor to tissue mechanical response. This strategy creates new opportunities for quantifying an injury mechanism (burst injury) that is common in blunt abdominal trauma, and will lead to advancement of high-fidelity virtual crash test dummies, and improved vehicle safety.
机械建模方法对于理解肝的流体和固体成分在冲击创伤过程中的相互作用非常重要。本研究使用多孔粘弹性（PVE）理论模拟无约束压缩应力松弛实验中的肝生物力学响应，应变率范围为 0.001 至 0.1 s(-1)。标本包括在加湿温度控制室内测试的 17 个离体猪肝样本。使用 ABAQUS 对肝反应进行建模，并使用非线性最小二乘算法确定最佳拟合参数。PVE 模型能够捕获猪肝在无约束压缩下的行为，斜坡阶段的回归分析表明模型与实验之间具有高度相关性（R(2) > 0.993，斜率 > 0.833，p < 0.05）。与传统粘弹性建模相比，PVE 建模的优势在于能够将间质流体压力作为组织力学响应的一个贡献因素进行检查。这种策略为量化钝性腹部创伤中常见的一种损伤机制（爆裂损伤）提供了新的机会，并将导致高保真虚拟碰撞试验假人和改进车辆安全的进步。
