A goat eye, wet lab model for training in Descemet membrane endothelial keratoplasty

Here we describe a new, non-human, ex-vivo model (goat eye model) for training surgeons in DMEK surgeons. In a wet lab setting, goat eyes were used to obtain a pseudo-DMEK graft of 8 mm from the goat lens capsule that was injected into another goat eye with the same maneuvers described for human DMEK. The DMEK pseudo-graft can be easily prepared, stained, loaded, injected, and unfolded into the goat eye model reproducing the similar maneuvers used for DMEK in a human eye, except for the descemetorhexis, which cannot be performed. The pseudo-DMEK graft behaves similar to human DMEK graft and useful for surgeons to experience and understand steps of DMEK early in learning curve. The concept of a non-human ex-vivo eye model is simple and reproducible and obviates the need for human tissue and the issues of poor visibility in stored corneal tissue.

Estimates of Space Radiation Exposure to Astronauts Using Male Voxel Model Based on MRI / 航天医学与医学工程

Objective To predict the astronaut organs radiation exposure and related health risks in the space radiation environment, the calculated method is studied. Methods A male voxel human model based on MRI and radiation data bank was build. The calculation was carried out with Monte Carlo particle transporting program GEANT4. Results The organ absorbed dose distribution and the effec-tive doses to the model in isotropic proton fields with energies ranges from 10 MeV to 500 MeV were obtained. Conclusion Based on the Chinese astronaut voxel model and the data set of proton spectrum measured in the space cabin, the cumulated dose in the model is gotten. The calculated skin dose is about 148.6 μGy/d, which is within in the range of 100 -300 μGy/d, published by USA and Russia.

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.

Particle Image Velocimetry Measurements for the Study of Nasal Airflow / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Several studies have utilized physical models or casts of the nasal cavity in an effort to understand the relationship between nasal anatomy and the distribution of inspired or expired airflow. This paper deals with the evaluation of nasal airflow characteristics during physiologic breathing in normal conditions. MATERIALS AND METHOD: The choana of a nasal model casting by a combination of rapid prototyping and solidification of clear silicone was connected to a pump that simulated physiological pressure in the upper airway system. Glycerin-water mixture was used as medium. The airstream was marked with polyvinyl spherical particles, and was observed through an solidificated clear silicone and analyzed with particle image velocimetry. RESULTS: Turbulence is clearly visible at the level of the head of the middle turbinate. The maximal velocity was recorded at the superior meatus. The flow rate was highest at the middle meatus. CONCLUSION: This model allows the investigation of airflow distribution and velocity under physiologic conditions. The main flow stream passes through the middle meatus.