Upper Cervical Spine In The Human Body Modeling And Auto High-speed Collisions With The Neck Injury

With the rapid development of highway in our country, the car collisionaccidents become frequently, and its proportion in road traffic accident isincreasing year by year, and these accidents often cause the serious harm to thepassenger because the impact.The human head, chest and neck injury caused bytraffic accidents are the main factors to cause death. In addition, the neck injuryis the common type of injury in all kinds of traffic accident.Neck injury notonly causes death but also leads to long-term sequelae. For the neck injurycaused by car crash, there are some investigations about low speed impact(usually less than or equal to15km/h) by some experts, and some usefulconclusions are obtained. However, its still unclear about the neck injury causedby car at high speed.On the one hand, because of the complex anatomicalstructure and physiological properties of cervical spine, the understanding of thedamage mechanism under low speed impact is still confused. On the other hand,the experimental verification of the cervical vertebra failure behavior under highspeed impact is difficulty to achieve.Therefore, it is necessary to explored theproblem that the neck under the high speed impact damage preliminarily.At present, experts have study the neck injury mechanism through varioustest and mathematical simulation. However, the test specimens are expensiveand difficult to obtain. Furthermore, there are exist limitations of ethics and poordegree of simulation of mechanical model and the multi-rigid-body model.However, with the development of the finite element technology, the finite element model can not only reflect the anatomical structure of human cervicaldetailed, but also simulate the biomechanical responses of cervical underdifferent loading conditions. The finite element analysis method is a commonand low cost method that analyze and predict the neck injury mechanismcaused by vehicle collision accidents effectively.In this paper, based on50percentile Chinese volunteers’ neck of the CTscan data provided by hospital, a finite element model of upper cervical spine ofhuman with high biological fidelity is established. The simulations of the modelunder the impact of30,60,90and120km/h are conducted and the dynamicresponse of the cervical under the high speed collision are analyzed. The modelis composed of cortical bone, cancellous bone, small joints, ligaments andintervertebral disc tissue, and given the corresponding material propertiesaccording to the references. Then the availability of the model has beenconfirmed through compared with experimental results.The neck injuries under high-speed front or back collision are studied usingthe established finite element model. The stress-time curves of vertebrae,intervertebral discs, transverse ligament and small joint are obtained. Byanalyzing the stress curves, the stress nephogram and injure position to discussthe failure mechanism of the upper cervical spine under front or back collisionwith different impact velocities. Results revealed the harm of each part of thecervical spine under the front and back collision with high speed and providesreference for subsequent investigations. The model of cervical vertebraestablished in this paper has highly biological simulation and reliability.Therefore, the model is able to be used for the study of neck injury mechanism.