Schmitt K-U, Snedeker J G
Institute for Biomedical Engineering, Swiss Federal Institute of Technology (ETH) and University of Zurich, Switzerland.
J Trauma. 2006 Apr;60(4):880-4. doi: 10.1097/01.ta.0000215573.19136.04.
The abdomen ranks third with regard to injured body regions, and urogenital trauma accounts for up to 10% of all abdominal injuries. Predictive numerical models are evolving as important tools for the development of preventative measures and preliminary clinical diagnostics. Such models require accurate biomechanical input data that at present is not sufficiently available.
The purpose of the present study was to determine the biomechanical response of whole, perfused porcine kidneys to blunt impact. Specifically of interest were the force-displacement characteristics of the organs, as well as the injury thresholds. Thirty nine young, adult pig kidneys (kidney mass 0.17 +/- 0.02 kg) were infused with physiologic saline solution, and impacted on their dorsal surface by a freely swinging right cylindrical pendulum. Two impact masses (2.1 and 4.7 kg) were used at varying impact velocities and corresponding impact energies. Resulting injuries were graded according to the AAST injury scale, and injury was related to impact mass, impact velocity, and impact energy.
It was determined that injury was best predicted by impact energy, and that for a given impact energy the resulting injury severity was relatively independent of either impact mass or impact velocity. For a moderate to severe injury, an impact energy threshold of 4 J, or a corresponding strain energy density of 25 kJ/m, was established. This information is essential to the development and implementation of accurate, predictive computational trauma models.
腹部是身体受伤部位中位列第三的区域，泌尿生殖系统创伤占所有腹部损伤的比例高达10%。预测性数值模型正逐渐成为制定预防措施和初步临床诊断的重要工具。此类模型需要准确的生物力学输入数据，而目前这些数据尚不充分。
本研究的目的是确定完整灌注的猪肾对钝性撞击的生物力学反应。特别感兴趣的是器官的力-位移特性以及损伤阈值。对39个年轻成年猪肾（肾质量0.17±0.02千克）灌注生理盐溶液，并用一个自由摆动的右圆柱摆锤撞击其背侧表面。使用了两种撞击质量（2.1千克和4.7千克），并采用不同的撞击速度和相应的撞击能量。根据美国创伤外科学会（AAST）损伤分级标准对造成的损伤进行分级，并将损伤与撞击质量、撞击速度和撞击能量相关联。
确定损伤最好由撞击能量预测，并且对于给定的撞击能量，所造成的损伤严重程度相对独立于撞击质量或撞击速度。对于中度至重度损伤，确定了4焦耳的撞击能量阈值或相应的25千焦/立方米的应变能密度。这些信息对于准确的预测性计算创伤模型的开发和实施至关重要。
