Li Zhigang, Liu Weiguo, Zhang Jinhuan, Hu Jingwen
School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing, China.
Int J Legal Med. 2015 Sep;129(5):1055-66. doi: 10.1007/s00414-015-1190-6. Epub 2015 Apr 22.
Skull fracture is one of the most common pediatric traumas. However, injury assessment tools for predicting pediatric skull fracture risk is not well established mainly due to the lack of cadaver tests. Weber conducted 50 pediatric cadaver drop tests for forensic research on child abuse in the mid-1980s (Experimental studies of skull fractures in infants, Z Rechtsmed. 92: 87-94, 1984; Biomechanical fragility of the infant skull, Z Rechtsmed. 94: 93-101, 1985). To our knowledge, these studies contained the largest sample size among pediatric cadaver tests in the literature. However, the lack of injury measurements limited their direct application in investigating pediatric skull fracture risks. In this study, 50 pediatric cadaver tests from Weber's studies were reconstructed using a parametric pediatric head finite element (FE) model which were morphed into subjects with ages, head sizes/shapes, and skull thickness values that reported in the tests. The skull fracture risk curves for infants from 0 to 9 months old were developed based on the model-predicted head injury measures through logistic regression analysis. It was found that the model-predicted stress responses in the skull (maximal von Mises stress, maximal shear stress, and maximal first principal stress) were better predictors than global kinematic-based injury measures (peak head acceleration and head injury criterion (HIC)) in predicting pediatric skull fracture. This study demonstrated the feasibility of using age- and size/shape-appropriate head FE models to predict pediatric head injuries. Such models can account for the morphological variations among the subjects, which cannot be considered by a single FE human model.
颅骨骨折是最常见的儿科创伤之一。然而,由于缺乏尸体试验,用于预测儿科颅骨骨折风险的损伤评估工具尚未完善。20世纪80年代中期,韦伯进行了50次儿科尸体坠落试验,用于虐待儿童的法医研究(婴儿颅骨骨折的实验研究,《法医学杂志》92: 87 - 94, 1984;婴儿颅骨的生物力学脆弱性,《法医学杂志》94: 93 - 101, 1985)。据我们所知,这些研究是文献中儿科尸体试验中样本量最大的。然而,由于缺乏损伤测量,限制了它们在调查儿科颅骨骨折风险方面的直接应用。在本研究中,使用参数化儿科头部有限元(FE)模型重建了韦伯研究中的50次儿科尸体试验,该模型被变形为具有试验中报告的年龄、头部尺寸/形状和颅骨厚度值的受试者。通过逻辑回归分析,基于模型预测的头部损伤测量结果,绘制了0至9个月大婴儿的颅骨骨折风险曲线。研究发现,在预测儿科颅骨骨折方面,模型预测的颅骨应力反应(最大冯·米塞斯应力、最大剪应力和最大第一主应力)比基于整体运动学的损伤测量结果(头部峰值加速度和头部损伤标准(HIC))是更好的预测指标。本研究证明了使用适合年龄和尺寸/形状的头部有限元模型来预测儿科头部损伤的可行性。这样的模型可以考虑受试者之间的形态学差异,而单一的有限元人体模型无法考虑这些差异。