• Journal of Mechanical Science and Technology
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• 제19권7호
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• pp.1424-1431
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• 2005

In this study, head injury by impact force was evaluated by numerical analysis with 3-dimensional finite element (FE) model. Brain deformation by frontal head impact was analyzed to evaluate traumatic brain injury (TBI). The variations of head acceleration and intra-cranial pressure (ICP) during the impact were analyzed. Relative displacement between the skull and the brain due to head impact was investigated from this simulation. In addition, pathological severity was evaluated according to head injury criterion (HIC) from simulation with FE model. The analytic result of brain damage was accorded with that of the cadaver test performed by Nahum et al.(1977) and many medical reports. The main emphasis of this study is that our FE model was valid to simulate the traumatic brain injury by head impact and the variation of the HIC value was evaluated according to various impact conditions using the FE model.

• Journal of Korean Neurosurgical Society
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• 제39권4호
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• pp.271-276
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• 2006

Objective : Despite the recent progress that has been made in intracerebral monitoring, it is still difficult to quantify the exact extent of primary brain damage after severe head injury. In this work, we investigate the role of S-100B protein as a serum marker of brain damage after severe head injury. Methods : 21 patients with severe head injury [GCS score <9] were selected for this prospective study. A venous blood sample was taken as soon as possible after head injury and the serum concentration of S-100B protein was measured daily for five consecutive days. The serum level of S-100B protein was compared with the patients' outcome. The outcome was measured twice, at hospital discharge and after 6 months of follow-up using the Glasgow Outcome Scale[GOS]. Results : Those patients who died within two weeks [after head injury] had a significantly higher serum S-100B value than those who survived [median, 9.64ug/L versus 2.91ug/L]. Seven [78%] of the nine patients who died had a maximum S-100B value of 2ug/L or higher, while three [25%] of the twelve surviving patients showed a maximum S-100B protein value of more than 2ug/L [P<005]. Conclusion : These results indicate that S-100B protein appears to be the most reliable index for estimating the extent of brain damage.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 추계학술대회 논문요약집
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• pp.16-16
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• 2003

In this study, for a safety assessment of wheelchair occupant in side impact, we used a dynamic sled impact test results. The test was carried out total 6 times and impact speed was 13g$\pm$0.43/28km/h$\pm$0.95, By using EURO SID-1 dummy, head performance criteria(HPC), abdominal peak force, etc. were measured. We evaluated wheelchair occupant safety by motion criteria(MC) which was measured by head, trunk and side deformation change of wheelchair and Head & Neck injury criteria(HNI) measured by using head and neck deformation angle and time relation. When we assumed that the maximum injury value in side impact was 100%, the results of motion criteria(MC) of wheelchair occupant were max 80.3, mim 32.3 and average 60.3%, Head & Neck injury criteria(HNI) value were max 118.4, min 14.5 and average 59.7%.

• Journal of Trauma and Injury
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• 제25권4호
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• pp.122-131
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• 2012

Purpose: Diffuse axonal injury (DAI) is clinically defined as a coma of over six hours in a head trauma victim without a focal mass lesion. The emergency physician usually resuscitates and stabilizes a comatose head trauma victim in the emergency Department. After assessment and treatment, the prognosis is very important to both the victim and the physician. The prognosis for DAI is based on Glasgow Coma Scale (GCS) and other imaging data. We investigated the prognostic value of computed tomography (CT) and gradient-echo magnetic resonance imaging (GRI) for head trauma victims with DAI. Methods: Fifty-three(53) head trauma victims of DAI were enrolled in this study from 2007 to 2012. During the study period of six years, data on trauma victims were collected retrospectively. We analyzed the differences in the Glasgow Outcome Scale (GOS) result between the CT and the GRI modalities. Results: We classified the study group by using GOS. Between the good outcome subgroup (GOS scores of 4 and 5) and the poor outcome subgroup (GOS score of 1-3), there were no statistical difference in sex, age, initial vital signs and initial GCS score. The good outcome subgroup had non-hemorrhage on CT(52%), which was correlated with good outcome and a shorter awakening time, while a larger number and a deeper location of hemorrhagic lesions on in GRI were correlated with poor outcome in DAI. Conclusion: We conclude that the existence of hemorrhagic lesions on CT, and the number and location of those lesions on GRI had good prognostic value for head trauma victims with DAI.

• 한국자동차공학회논문집
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• 제13권5호
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• pp.29-34
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• 2005

141,841 car-to-car collision had occurred in 2003, and among the accidents 51,796 were rear-end impact. According to insurance company for loss or damage, more than $60\%$ of rear-end impact victims suffer neck injury. This means at least 31,000 neck injury victims have happened in 2003. More than $97\%$ of the neck injury victims have low severity injury than A.I.S 2. Head restraint, which is designed to limit rearward head movement and equipped on seat, can considerably protect neck from rear-end impact. In this paper we evaluated head restraint geometry and drivers' sitting position according to RCAR standard and carried out low speed volunteer crash test. The crash speed is 4km/h and N.I.C value is used to determine injury probability. Through these research results we can introduce the method to prevent neck injury at rear-end impact.

• 자동차안전학회지
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• 제6권2호
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• pp.12-17
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• 2014

The number of vehicle accidents related to the side impact has increased since 1990 in Korea, thus the side impact test has been performed as one of the major vehicle evaluations of the Korean New Car Assessment Program(KNCAP) in 2003. A total of 77 vehicles of eight different types(compact, small, semi-midsize, midsize, and large sedans and small, midsize, and large sports utility vehicles) were tested in side impact and side pole impact conditions. In this study, the head and thorax injury values(HICs and chest deflections) of the side impact tests performed between 2003 and 2013 were investigated in terms of vehicle type, test year, and test condition. The recent vehicles showed better safety performances(lower injury values) and similar injury patterns were obtained between side impact and pole side impact tests.

• 한국자동차공학회논문집
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• 제9권2호
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• pp.99-106
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• 2001

NHTSA has been conducting biomechanical studies to reduce inujuries sustained sustained during automotive collision. Furthermore, NHTSA added the regulation to the FMVSS 201, limiting the equivalent HIC(Head Injury Criterion) value under 1000. In the presont work, a methodology was developed for the optimum design of the A-pillar trim with rib-structures. The design variables for the rib-strucrures were the transverse spacing, the longitudinal spacing, and the thickness. The required sets of the design varibles were decided based on the design of experiments. The head impact simulations were carried out using the LS-DYNA3D, and the HIC(d) values were computed using the resulrs of the head impact simulation. The objective function was constructed using the response surface methed (RSM). When the obtained optimum values were not inside the region of interest, the design proceduers were repeated by changing the region of interest. Finally, an A-pillar trim with rib-structures, which resulred in HIC(d) value under 850 for 15 mph head-trim impact, was developed.

• 자동차안전학회지
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• 제5권2호
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• pp.45-50
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• 2013

The whiplash Injuries due to rear collision occur frequently. As result, in many countries, seat performance is being assessed and developed to improve head whiplash injury in rear collision of passenger car. This study compares whiplash assessment methods in each country. Using the DFSS(Design for Six Sigma) method, the correlation between influence parameters of head restraints and whiplash injury criteria is analyzed. Four control factors are used in this study. And total 11 whiplash injury criteria from NCAP(New Car Assessment Program) of Korea, Europe, China and IIHS(Insurance Institute for Highway Safety) of USA are used for output response. By the experimental design, L9 orthogonal coordinate system is configured and is tested by sled test equipment, twice. By using average assay value and ANOVA, the correlation between control factors and injury criteria has been comprehended. Optimization design of head restraint according the regional seat safety assessment was derived through the correlation.

• 한국가스학회지
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• 제18권1호
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• pp.68-74
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• 2014

본 연구에서는 헬멧의 충격응답을 분석하기 위한 단순진동모델을 제시하였다. 실제 헬멧 설계 및 검증과정에서 사용하는 데이터에 기반을 두고 단자유도 진동모델을 채택하였다. 충격에 의한 과도진동응답을 산출하여, 헬멧의 감쇠, 고유진동수, 충돌속도와 같은 인자들이 헬멧의 충격응답에 미치는 영향을 고찰하였다. 최대 G-가속도는 감쇠가 증가함에 따라 감소하였고, 감쇠비가 0.6 이상이 되면 최대 가속도의 값은 변화가 없었다. 고유진동수와 충돌속도에 관하여는 선형적으로 증가하였다. 두부 상해기준(Head Injury Criterion, HIC) 과 최대가속도의 관계도 제시하였다. 본 연구에서의 해석모델이 고품질 경량화 헬멧의 설계과정에서 경제성 제고에 활용될 수 있기를 기대한다.

• 한국전문물리치료학회지
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• 제5권3호
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• pp.48-55
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• 1998

The purpose of this study was to identify vital capacity (VC) in relation to the changing position of 19 patients with spinal cord injury (SCI) and 20 normal controls. Among the 19 SCI patients, there were 9 quadriplegics and 10 paraplegics. The vital capacity was measured in each subject during sitting, standing, lying, and head down position of 30 degrees. The data were analysed by the Kruskal-Wallis test, Mann-Whitney test, and Wilcoxon signed rank test. For the SCI, significant difference of VC accoring to the 4 positions between quadriplegics and paraplegics. In the control group, significant difference of VC according to the 4 positions. In 4 positions the VC of men were significantly larger than that of women between two groups. No statistical significant difference was shown in VC by the postural change between quadriplegics and paraplegics.