Application of Korean Mechanical 3D Bone Model to the MADYMO(R) / 대한법의학회지

MADYMO(R) (Mathematical Dynamic Models) is a computer software with a multibody dynamics solver, which can be employed to reconstruct and interpret dynamic motions of the human body in impacts. The human model of the software is composed of many ellipsoidal structures, which makes it possible to interpret dynamic whole-body motions and calculate applied forces to human body parts. However, this model has some disadvantage to interpret injuries of the smaller body parts such as ribs, vertebral bodies or intervertebral discs. After achieving the finite element bone model produced by CT and software BIONIX BODYBUILDER(R) (finite element modeller), we tried to import this model into the MADYMO(R) and parts of the human bone model were successfully imported to it. Importing of the whole bone model was, however, impossible because of the numerous elements. The coming experiments need to reduce the number of elements in the whole human bone model and incorporate ligaments, tendons and muscles into each separated part of bone models.

Neck fracture case at low speed in frontal collision / 대한법의학회지

Neck fracture is a major cause of death in traffic accidents and this injury pattern occurred normally in a frontal collision or overturn process. This study investigates a case of neck fracture from a low speed collision. In this case examined, the passenger in the front seat of the car was pulled back and did not have the seat belt on. As the vehicle slipped on a frozen road surface in a downward hill and crashed into the shoulder of the road at low speed. But strangely, even though his neck is fracture there were not any collision marks on interior of the car. This study applied computer simulation to analyze this case and we found out that the upper part of the person was rotated and raised at the time of collision and his neck was fully bent by interference with roof and we also know that the seat belt did not resist the passenger who pulled back his seat.

A Case Study for the Reconstruction of Crime Scene by Computer Simulation / 대한법의학회지

Especially in design of automobile, there are many professional softwares based finite element or multi-body like Madymo, Pam-Crash, Ansys. These program have been released almost every car maker and university. Also in accident reconstruction fields, there are some softwares like PC-Crash, HVE was developed. Unfortunately these programs for accident reconstruction are so general and its input data are so limited, it is very difficult or even impossible to analyze some special cases. In this study, we reconstruct two crime scenes using Madymo program. Although this program was developed for design of car, we apply to crime scene reconstruction. First case is regarding traffic accident. A car was fell under 5m from the road and turn over and then move about 40m. Finally the driver eject from the car. Second case is regarding suicide by hanging. When the police investigate the crime scene at first time, they assume that this crime is a murder case but we carried out autopsy and investigated the crime scene again and analyzed by computer simulation and finally find out this crime is suicide case not murder.

A Case Study for the Spine Fracture of a Pedestrian Impacted by SUV / 대한법의학회지

The civilization has given us a great comfort and convenience but also it has been threatening our life at the same time. Among these causes of death the traffic accident is the most dangerous thing to threat our life in recent years. According to the report of traffic accident in 2003, the pedestrian to car accident is almost 50% of all types of traffic accident and this percentage is very high level compare to other countries. So this is why we have to focus on this field of accident. This case is as follows, when a pedestrian was riding a bicycle and crossing the road, a taxi hit the bicycle with left outside mirror. The impact was not so severe, the pedestrian stood up by himself. Unfortunately he was impacted once again by a SUV which was following behind the taxi. The evidence were the SUV, clothing and victim. A complete autopsy was performed on the victim. The skull was slightly fractured with line shape and showed hypodermal bleeding under the head skin. The thoracic vertebrae of No. 11-12 was fractured. The cause of death was apparently head trauma and fracture of thoracic vertebrae. But we could not explain why the thoracic vertebrae was fractured without damage of internal organs in chest and abdomen. To analyze this case, we used a dynamic analysis program Madymo V6.2 and applied the Hybrid-III human model. Finally we could prove that if the pedestrian stand against the SUV, the bending moment in spine was raised suddenly at the beginning of impact. At this moment the leg was started to be move to the backward of pedestrian but the upper part of body could not move because of inertia. This bending moment make the spine hyper-extension and this level of moment can fracture the spine enough in low speed of SUV. In this study we analysis the car to pedestrian accident with engineering view and introduce the detail analysis method to reconstruct the accident involving the human trauma.