Center for Applied Biomechanics, University of Virginia, Charlottesville, VA, USA.
Center for Applied Biomechanics, University of Virginia, Charlottesville, VA, USA.
Comput Biol Med. 2021 Sep;136:104700. doi: 10.1016/j.compbiomed.2021.104700. Epub 2021 Jul 31.
Traumatic aortic injury (TAI) is one of the leading causes of fatalities in blunt impact. However, there is no consensus on the injury mechanism of TAI in traffic accidents, mainly due to the complexity of occurrence scenarios and limited real-world crash data relevant to TAI. In this study, a computational model of the aorta with nonlinear mechanical characteristics and accurate morphology was developed and integrated within a thorax finite element model that included all major anatomical structures. To maximize the model's capability for predicting TAI, a multi-level process was presented to validate the model comprehensively. At the component level, the in vitro aortic pressurization testing was simulated to mimic the aortic burst pressure. Then, a sled test of a truncated cadaver was modeled to evaluate aorta response under posterior acceleration. The frontal chest pendulum impact was utilized to validate the performance of the aorta within full body model under direct chest compression. A parametric study was implemented to determine an injury tolerance for the aorta under these different loading conditions. The simulated peak pressure before aortic rupture was within the range of the experimental burst pressure. For the sled test, the simulated chest deflection and cross-sectional pressure of the aorta were correlated with the experimental measurement. No aorta injury was observed in simulated results of both sled test and chest pendulum impact, which matched the experimental findings. The present model will be a useful tool for understanding the TAI mechanisms, evaluating injury tolerance, and developing prevention strategies for aortic injuries.
创伤性主动脉损伤（TAI）是钝性冲击致死的主要原因之一。然而，由于发生场景的复杂性和与 TAI 相关的真实世界碰撞数据有限，对于交通事故中 TAI 的损伤机制尚未达成共识。在这项研究中，开发了一种具有非线性力学特性和精确形态的主动脉计算模型，并将其集成到包含所有主要解剖结构的胸部有限元模型中。为了最大限度地提高模型预测 TAI 的能力，提出了一个多层次的过程来全面验证模型。在组件级别，通过体外主动脉加压测试来模拟主动脉破裂压力。然后，对截断的尸体进行 sled 测试，以评估在后向加速度下主动脉的响应。采用正面胸部摆锤冲击来验证全身模型中主动脉在直接胸部压缩下的性能。进行了参数研究，以确定在这些不同加载条件下主动脉的损伤容限。模拟主动脉破裂前的峰值压力在实验破裂压力范围内。对于 sled 测试，模拟的胸部挠度和主动脉的截面压力与实验测量相关。 sled 测试和胸部摆锤冲击的模拟结果均未观察到主动脉损伤，这与实验结果相符。该模型将成为理解 TAI 机制、评估损伤容限以及开发主动脉损伤预防策略的有用工具。
