• 한국자동차공학회논문집
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• 제13권1호
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• pp.132-139
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• 2005

The driving position of head restraints and the relative risk of neck injury were studied in the computer simulation. MADYMO human model with the detail neck model was used to define the magnitude and direction of internal forces acting on the cervical spine during rear-end impact and to determine the effect of the initial position of the occupant's head with respect to the head restraints. Maximum reaction forces were generated during the head contact to the restraint and relatively large forces were generated at each spinal components in lower cervical spine in proportion to backset and height distance increasement.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.240-243
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• 2005

Osteoporosis, one of the age-related disease causes vertebra body fracture due to weakening trabecular bone and makes a substantial effect on load sharing among vertebras. Recently, vertebroplasty is one of the most popular treatment, as augmenting PMMA into vertebra. Biomechanical studies about vertebroplasty have been evaluated by several experiments or analysis under static loading but there has been no study on response under dynamic loading. This study included the FE analysis of patients who treated vertebroplasty under dynamic loading. For this study, 3-D FE model of lumbar spine(L1-L2) was modeled from CT scanning data and compared with experimental results in vitro in order to validate this model. Biomechanical behavior about each of normal person, osteoporotic patient and patient treated vertebroplasty for quantitative evaluations of vertebroplasty was compared and investigated.

• 한국CDE학회논문집
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• 제13권1호
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• pp.58-66
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• 2008

The artificial discs have recently used to preserve the motion of the treated segment in lumbar spine surgery. However, there have been lack of biomechanical information of the artificial discs to explain current clinical controversies such as long-term results of implant wear and excessive facet contact forces. In this study, we investigated the biomechanical effects of three artificial implants on the lumbar spinal segments by finite element analysis. The finite element model of intact lumbar spine(L1-S) was developed and the three implants were inserted in L4-L5 segment of the spine model. 5 Nm of flexion and extension moments were applied on the superior plate of L1 with 400 N of compressive load. Excessive motions and high facet contact forces at the surgical level were generated in the all three implanted models. In the flexion, the peak von-Mises stresses in the semi-constrained type implant was higher than those in the un-constrained type implant which would cause wear on the polyethylene core. The results of the study would provide a biomechanical guideline for selecting optimal surgical approach or evaluating the current design of the implants, or developing a new implant.

• 대한의용생체공학회:의공학회지
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• 제44권4호
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• pp.293-301
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• 2023

Scoliosis is a three-dimensional deformation of the spine that is a deformity induced by physical or disease-related causes as the spine is rotated abnormally. Early detection has a significant influence on the possibility of nonsurgical treatment. To train a deep learning model with preprocessed images and to evaluate the results with and without data augmentation to enable the diagnosis of scoliosis based only on a chest X-ray image. The preprocessed images in which only the spine, rib contours, and some hard tissues were left from the original chest image, were used for learning along with the original images, and three CNN(Convolutional Neural Networks) models (VGG16, ResNet152, and EfficientNet) were selected to proceed with training. The results obtained by training with the preprocessed images showed a superior accuracy to those obtained by training with the original image. When the scoliosis image was added through data augmentation, the accuracy was further improved, ultimately achieving a classification accuracy of 93.56% with the ResNet152 model using test data. Through supplementation with future research, the method proposed herein is expected to allow the early diagnosis of scoliosis as well as cost reduction by reducing the burden of additional radiographic imaging for disease detection.

• Journal of Yeungnam Medical Science
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• 제20권2호
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• pp.160-168
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• 2003

요추부 척추에 기구를 시술한 유한요소 복합체 모델을 이용하여 제 4-5 요추간판에 대한 해석을 수행한 결과, 근육의 작용을 케이블과 케이블 가이드로써 단순화 모사한 follower 하중에서 수직하중인 경우보다 높은 압축력을 나타내어 더욱 안정함을 보였고 불안정성의 원인이 되는 전단력과 굽힘모멘트의 발생은 미미하였다. 장분절 고정에 의한 인접 분절에 전단력이 증가됨을 실험적으로 보였는데, 이는 장분절 고정이 퇴행성 변화 촉진에 기여할 것으로 추정된다.

• 대한기계학회논문집
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• 제16권4호
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• pp.723-736
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• 1992

본 연구에서는 복압력(abdominal pressure) 및 복근(abdominal musles)만을 제외(하중의 계산시 이들의 역활을 포함하였다.) 한 요추골 운동에 관계하는 모든 역 학적 요소를 포함시키고 해부학적으로 매우 충실한 실험용 광탄성 모델과 하중장치를 개발하여, 이러한 모델과 하중장치의 유효성을 임상의학적으로 규명 하는것을 본 연구 의 목적으로 한다.

• 보건행정학회지
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• 제28권1호
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• pp.53-69
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• 2018

Background: This study investigates association modified category medical specialization (CMS) and hospital charge, length of stay (LOS), and mortality among lumbar spine disease inpatients. Methods: This study used National Health Insurance Service-cohort sample database from 2002 to 2013, using stratified representative sampling released by the National Health Insurance Service. A total of 56,622 samples were analyzed. The primary analysis was based on generalized estimating equation model accounting for correlation among individuals within each hospital. Results: Inpatients admitted with lumbar spine disease at hospitals with higher modified CMS had a shorter LOS (estimate, -1.700; 95% confidence interval [CI], -1.886 to -1.514; p<0.0001). Inpatients admitted with lumbar spine disease at hospitals with higher modified CMS had a lower mortality rate (odds ratio, 0.635; 95% CI, 0.521 to 0.775; p<0.0001). Inpatients admitted with lumbar spine disease at hospitals with higher modified CMS had higher hospital cost per case (estimate, 192,658 Korean won; 95% CI, 125,701 to 259,614; p<0.0001). However, inpatients admitted with lumbar spine surgery patients at hospitals with higher modified CMS had lower hospital cost per case (estimate, -152,060 Korean won; 95% CI, -287,236 to -16,884; p=0.028). Inpatients admitted with lumbar spine disease at hospitals with higher modified CMS had higher hospital cost per diem (estimate, 55,694 Korean won; 95% CI, 46,205 to 65,183; p<0.0001). Conclusion: Our results showed that increase in hospital specialization had a substantial effect on decrease in hospital cost per case, LOS, and mortality, and on increase in hospital cost per diem among lumbar spine disease surgery patients.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.280-283
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• 1997

Human cervical spine has to protect the neural components and vascular structures. Also, it must have the flexibility afforded by an extensive range of motion to integrate the head with the body and environment. Because of these two-sided features, human cervical spine has very complicated shapes and their injury mechanisms are not fully understood yet. We have developed analytical model of human CS by using the finite element method. The model has been verified with in vivo and in vitro experimental results. From the qualitative analysis of simulation results, we were able to explain some of the fundamental mechanisms of neck pain. Further more, this FE model of human CS can be used as an analytical tool or biomechanical design of the clinical device and safety restraints.

• 한국정밀공학회지
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• 제27권2호
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• pp.137-144
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• 2010

In general, spinal fusion surgery takes pressure off the pain induced nerves, by restoring the alignment of the spine. Therefore spinal fixation system is used to maintain the alignment of spine. In this study, a biomechanical study was performed comparing the SROM(Spinal Range Of Motion) of three types of system such as Rigid, Dynesys, and Fused system to analyze the behavior of spinal fixation system inserted in vertebra. Dynesys system, a flexible posterior stabilization system that provides an alternative to fusion, is designed to preserve inter-segmental kinematics and alleviate loading at the facet joints. In this study, SROM of inter-vertebra with spinal fixation system installed in the virtual vertebra from L4 to S1 is estimated. To compare with spinal fixation system, a simulation was performed by BRG. LifeMOD 2005.5.0 was used to create the human virtual model of spinal fixation system. Through this, each SROM of flexion, extension, lateral bending, and axial rotation of human virtual model was measured. The result demonstrates that the movement of Dynesys system was similar to normal condition through allowing the movement of lumbar.

• 대한기계학회논문집A
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• 제33권7호
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• pp.637-644
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• 2009

We have analyzed the biomechanical characteristics of cervical spine after total disc replacement using finite element analysis. A finite element model of C2-C7 spinal motion segment was developed and validated by other experimental studies. Two types of artificial discs, semi-constraint and un-constraint, were inserted at C6-C7 segments. Inferior plane of C7 vertebra was fixed and 1Nm of moment were applied on superior plane of C2 vertebra with 50N of compressive load along follower load direction. Mobility of the cervical spine in which each artificial disc inserted was higher than that of intact one in all loading conditions. Also, high mobility at the surgical level after total disc replacement could lead higher facet joint force and ligaments axial stresses. The results of present study could be used to evaluate surgical option and validate the biomechanical characteristics of the implant in total disc replacement in cervical spine.