The Research On The Modeling Methodology Of Finite Element Model And Injury Of Child Neck

Traffic accidents are one of the major factors that lead to serious spinal injuries among children.Injury risks and economic loss caused by spinal injury are enormous,although they just account for less than 10%of whole body injury for a child.About 75%of children's spine injuries occur in the neck,and there is a high mortality rate in children's neck injury.Due to the limitation of ethics and morality factors,biomechanical study of children's neck injuries is still very scarce.Research results from adult subjects are often scaled to obtain the biomechanical response of children's neck.However,the neck of children has different geometry structures and material properties with adults,like the laxity of ligaments,decreased angle of facet joints,immature vertebral,which also lead to different injury mechanism between children and adults even for different individuals among children.In addition,the current assessment tool for children's neck injury cannot be used to assess the neck injury of children with different body attributes.Therefore,a method was proposed in this study to build a parametric neck finite element(FE)model for 4-11 year-old children based on statistical analysis and the mesh morphing,and geometry and impact responses comparison were performed among different gender,age and BMI(Body Mass Index)based on the parametric neck FE model Main works and studies of this paper were shown as follows:1)Aiming to the problems of time-consuming,low concordance and high difficulty in the extraction of landmarks in the current parametric modeling method,a method of rapid extraction of landmarks was proposed and applied to the modeling of a C4-C5 cervical segment of a 9-year-old child.The validity of the FE model established by this method was verified under various experimental conditions through post mortem human subjects(PMHS)test data.2)Using 28 clinical computed tomography(CT)data,the parametric neck FE model for 4-11 year old children was established accounting for the age,height and BMI based on the statistical analysis and mesh morphing,including image threshold,landmarks extraction of landmarks,adjustment of landmarks,statistical analysis of geometric shapes,and mesh morphing method.The model could predict the neck geometry of children under any reasonable parameters combination of age,height and BMI.3)A series of neck FE models were rapidly generated when inputting reasonable parameter combinations of age,height and BMI.The effect of body attributes on geometry and mechanical response of neck was studied.The research results showed that compared with the traditional method of extracting landmarks,the method proposed in this study could save time by 2/3?3/4.The FE model which was rapidly established by mesh morphing has reasonable geometric accuracy,similar mesh quality with baseline FE model and high biomechanical fidelity.The body attributes has significant effect on the geometry and mechanical response of neck.The development of parametric neck FE model for 4-11 year-old children is of great significance to study the mechanism of neck injury and the development of children's neck protection tools.