Study On Mechanism Of Brain Deceleration Injury

The movement of head was suffocated due to the outside force, the trauma on skull by the force could result in trauma of localization. Whereas several movement of the brain tissues were lagging after that of head, seriously, the trauma on tissues from the impacts brings about some mechanics effects as crushing, laceration and stretch was considered as the deceleration injury, which is a kind of traumatic brain injury (TBI), with great possibility of occurrence in traffic and falling injury. This research applied the investigations in the traffic incidents, finite elment(FE) simulation and the experiments of the deceleration injury of rabbit heads for the study of invasions, occurrence mechanism and the specialty of injury of the deceleration injury.The pedestrians who are walking along without any protection from these accidents would be such an inclination in suffering from the road traffic Accident (RTA) that the brain injury was the main reason resulting in the injury and death of the pedestrian. The processes of acceleration and deceleration are performing in the process of the brain injury among the passengers in traffic incidents, with the process of deceleration-acceleration-deceleration or only deceleration. The investigation on vehicle-pedestrian accident in multi-areas in China could play an important role in cutting down the accident rate and mitigating the brain injury, espicially brain deceleration injury.TBI were significantly affected by the distribution of the stress and strian meeting the injury threshold. The FE model which be constructed with precision and standard by imitation of Chinese head, it could be operated in discussion the stress wave from the deceleration injury as well as the distribution in stress, so as to study the occurrence mechanism for the application in a certain protection, diagnosis and treatment of the deceleration injuryFinally, the development of the experiment of the deceleration injury on animals could be applied in the study on the occurrence mechanism of that on the basis of injury characteristic of the deceleration injury on animal and biomechanics mechanism, however, the advanced treatment of the deceleration injury are also been improved. The main methods and conclusions as following,I, An specific investigation among the Car- pedestrian traffic incidents were studied according to a multi-dimensional model including human– car– environment. The results show that the pedestrian who are crossing the road tends to have more possibility of injury in the traffic incidents. The adult was observed in recent and temporal cases, whereas the highest occurrence in the injuring and dead pedestrian, male and the old were also observed with more possibility in the injury and death than that among female and other ages. The multi-injury observed in cases was more than other injury in pedestrian injury, the percentage of head and extremities injury were higher than these of injury. Consequently, the fatality of pedestrian was mostly resulted in the brain injury. The severity of injury among children was obviously worse than the injury among adult. According to the analyses of traffic imitating by means of empirical formula and multi-body dynamatics, the results show that the severity of injury including head injury was mainly affected by the velocity of car impacting, the process of head injury of pedestrian contains acceleration and deceleration, the latter could result in the brain deceleration injury which be characteristic as the high incidence of disease and the severity of injury.Ⅱ, By terms of three-dimensional image reconstruction of the head, geometry model reconstruction, meshing of finite element model and assembling of finite element models et al, a plenty of information related to the human anatomy was contained in the Chinese Visible Human Data for the propose of contracting finite element model of the visible human head. The results show that the number of nodes and elements are 31223 and 119911 respectively, all the elements are soild elements, the head constructed in finite element model which is essentially similar with the head structured in anatomization could be more typical and comparable geometrically. Specifically, the paRTAcular operation on cranium viscerale and cranium viscerale which were constructed coarsely formerly could be applied in the biomechanical researches on the viscerale. The first FE model based on CVH was an important step to transplant Visible Human to Digital physics Human, which could take more effect in developing the CVH.Ⅲ, The model of imitating the brain deceleration injury which be caused by the heavy, still and blunt objects impacting on forehead or pars temporalis by means of Hypermesh software. The diffusion and distribution of brain stress wave could be calculated in LS-DYNA for further study. The results show when the deceleration injury occurred on forehead and pars temporalis, the movement of stress wave was a radiate diffusion around from the brain impact point. The stress impacted on brains was centralized in the positions of the free extremity on the broken and weak extremity of skull as well as the irregular extremity on cranium viscerale, the stress on skull was the strongest of these. The below of brain tissues were endured the strongest stress of which wave diffuses from the below of brain tissues to inner brain with the velocity of attenuation. The bottom of the brain contains the position of stress centralization. The stress centralization in opposite position of deceleration injury on forehead impact position was not found. The stress centralization in opposite position of deceleration injury on pars temporalis impact position was found. The finite element simulation of deceleration injury could analyze a certain clinical case by means of stress diffusion and distribution for propose of decreasing the missed diagnosis and misdiagnosis of brain deceleration injury.Ⅳ, A new type of injuring setting for researching the deceleration injury has been developped and applied for invention patent. The experience on rabbit brain deceleration injury was operated from the procedure of general observation, CT observation and pathological observation. The results show that the setting could be applied in the researching on small animal deceleration injury experiment. The three rabbit brain deceleration injury models constructed by the degrees of slightness, mildness and severity. The injury on deceleration injury specifically includes skull fracture, cerebral contusion, subdural hemorrhage, brain substance hemorrhage and contrecoup. The pathological change in deceleration injury mainly includes hemorrhagic contusion and cerebral edema. The brain decelaRTAon injury could be deduced by stress wave propagation and stress distribution.