Computational Modeling of Traffic Related Thoracic Injury of a 10-Year-Old Child Using Subject-Specific Modeling Technique FENG ZHU, 1 BINHUI JIANG, 1,2 JINGWEN HU, 3,4 YULONG WANG, 2,3 MING SHEN, 1 and KING H. YANG 1 1 Bioengineering Center, Wayne State University, Detroit, USA; 2 Key State Lab of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, China; 3 University of Michigan Transportation Research Institute, Ann Arbor, USA; and 4 Department of Mechanical Engineering, University of Michigan, Ann Arbor, USA (Received 6 April 2015; accepted 19 June 2015) Associate Editor Karol Miller oversaw the review of this article. Abstract—Traffic injuries have become a major health- related issue to school-aged children. To study this type of injury with numerical simulations, a finite element model was developed to represent the full body of a 10-year-old (YO) child. The model has been validated against test data at both body-part and full-body levels in previous studies. Repre- senting only the average 10-YO child, this model did not include subject-specific attributes, such as the variations in size and shape among different children. In this paper, a new modeling approach was used to morph this baseline model to a subject-specific model, based on anthropometric data collected from pediatric subjects. This mesh-morphing method was then used to rapidly morph the baseline mesh into the subject-specific geometry while maintaining a good mesh quality. The morphed model was subsequently applied to simulate a real-world motor vehicle crash accident. A lung injury observed in the accident was well captured by the subject-specific model. The findings of this study demonstrate the feasibility of the proposed morphing approach to develop subject-specific human models, and confirm their capability in prediction of traffic injuries. Keywords—Traffic injury, Pediatric model, Sample-specific modeling, Finite element method. INTRODUCTION Deaths and serious injuries associated with road traffic are of daily concern on a worldwide basis, and the most vulnerable group is children between the ages of 6 and 14 years. 8 In the United States (US) alone, approximately 1500 of these school-age children die annually in motor- vehicle crashes. 8 Restraint systems intended for adults are not adequate for the protection of children’s smaller bodies. Children between the ages of 0 and 5 years are protected by mandatory child seats, whereas no special provision has been made for 6–14 year olds. To accom- modate the high demand for measures to protect this vulnerable group, more in-depth studies are needed regarding responses to variations in shapes and sizes associated with school-aged children. While methodologies for studying traffic injuries do exist, each has limitations or inadequacies. Conven- tional methodologies include testing with human and animal cadavers, use of anthropomorphic test devices (ATDs), and modeling with numerical simulations. Due to ethical concerns, it is extremely difficult to conduct large-scale tests with pediatric cadavers. As a result, data obtained using pediatric specimens are very rare and highly scattered. ATDs, such as Hybrid III-family crash dummies are made from artificial mate- rials like metals and rubbers. Their mechanical responses are very different from those of real human body responses. To eliminate the aforementioned limitations, numerical modeling [frequently finite element (FE) modeling] has been widely accepted as a major alternative approach to supplement physical tests. However, full body numerical models for children in this age group are still very much limited. Okamoto et al. 30 developed a 6- year-old (YO) whole body model where the lower extremities were reconstructed from magnetic resonance imaging (MRI) data of a 6-YO volunteer. Ruan et al. 35 developed a 6-YO full body model based on computed tomography (CT) images. Neither model has been suffi- ciently validated against test data at either the component or the system level. More recently, a detailed 10-YO, full- body FE model was built at Wayne State University (WSU). This model was developed from CT and MRI images of appropriately aged children and represented a 10-YO child of average height and weight. Validations Address correspondence to Feng Zhu, Bioengineering Center, Wayne State University, Detroit, USA. Electronic mail: fengzhume@ gmail.com Annals of Biomedical Engineering (Ó 2015) DOI: 10.1007/s10439-015-1372-x Ó 2015 Biomedical Engineering Society