Sun Zhaonan, Gepner Bronislaw D, Lee Sang-Hyun, Oyen Michelle L, Rigby Joshua, Cottler Patrick S, Hallman Jason J, Kerrigan Jason R
Center for Applied Biomechanics, University of Virginia, Charlottesville, VA 22911.
Department of Engineering, East Carolina University, Greenville, NC 27858.
J Biomech Eng. 2022 Mar 1;144(3). doi: 10.1115/1.4052577.
The characterization of human subcutaneous adipose tissue (SAT) under high-rate loading is valuable for development of biofidelic finite element human body models (FE-HBMs) to predict seat belt-pelvis interaction and injury risk in vehicle crash simulations. While material characterization of SAT has been performed at 25 °C or 37 °C, the effect of temperature on mechanical properties of SAT under high-rate and large-deformation loading has not been investigated. Similarly, while freezing is the most common preservation technique for cadaveric specimens, the effect of freeze-thaw on the mechanical properties of SAT is also absent from the literature. Therefore, the aim of this study was to determine the effect of freezing and temperature on mechanical properties of human SAT. Fresh and previously frozen human SAT specimens were obtained and tested at 25 °C and 37 °C. High-rate indentation and puncture tests were performed, and indentation-puncture force-depth responses were obtained. While the chance of material failure was found to be different between temperatures and between fresh and previously frozen tissue, statistical analyses revealed that temperature and freezing did not change the shear modulus and failure characteristics of SAT. Therefore, the results of the current study indicated that SAT material properties characterized from either fresh or frozen tissue at either 25 °C or 37 °C could be used for enhancing the biofidelity of FE-HBMs.
在高速加载条件下对人体皮下脂肪组织（SAT）进行表征，对于开发生物逼真的有限元人体模型（FE-HBMs）以预测车辆碰撞模拟中安全带与骨盆的相互作用及损伤风险具有重要价值。虽然已在25°C或37°C下对SAT进行了材料表征，但尚未研究温度对高速和大变形加载条件下SAT力学性能的影响。同样，虽然冷冻是尸体标本最常用的保存技术，但文献中也没有关于冻融对SAT力学性能影响的报道。因此，本研究的目的是确定冷冻和温度对人体SAT力学性能的影响。获取新鲜的和先前冷冻的人体SAT标本，并在25°C和37°C下进行测试。进行了高速压痕和穿刺试验，并获得了压痕-穿刺力-深度响应。虽然发现温度之间以及新鲜组织和先前冷冻组织之间材料失效的可能性不同，但统计分析表明，温度和冷冻并未改变SAT的剪切模量和失效特性。因此，本研究结果表明，在25°C或37°C下从新鲜或冷冻组织表征的SAT材料特性可用于提高FE-HBMs的生物逼真度。
