• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.139-143
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• 2005

As increasing gastrointestinal pathologies, general and thoracic surgeries using circular staplers have been dramatically increased. Because of convenience for surgical procedure, recently, various circular staplers for anastomosis have been used widely. Since the circular staplers conventional have used the displacement control method, however, the anastomosis could have various biomechanical conditions. To do that, biomechanical system of gastrointestinal soft tissue should be examined to control the anastomotic condition. In this study, a new intelligent robot used in circular anastomosis. The intelligent robot driven by a stepper motor and controlled by a digital signal processor.

• 한국운동역학회지
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• 제25권2호
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• pp.183-190
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• 2015

Objective : Walking with a Material handling is an activity frequently undertaken by agricultural workers in Korea, due to the nature of their work. This study aimed to investigate differences in biomechanical variables according to the mechanical alignment of the lower limbs when walking with a heavy load, and to use this as basic data in the design of various working environments to reduce the skeletomuscular burden on the knee joint. Method : The study subjects comprised of 22 right-foot dominant adult men and women aged between 20 and 23 years. The subjects were divided into a varus or valgus group according to the mechanical alignment of the lower limb by using radiographic findings. The subjects walked without any load and with a load of 10%, 20%, or 30% of their body weight held in front of them. The Kwon3d XP program was used to calculate biomechanical variables. Results : The flexion/extension moment of the knee joint showed a decreasing trend with increased load, irrespective of the mechanical alignment of the lower limb, while the varus group did not show normal compensatory action when supported by one leg at the point of maximum vertical ground reaction force. In addition, in terms of the time taken, subjects showed no difficulties in one-foot support time up to 20%/BW, but at 30%/BW, despite individual differences, there was an increase in single limb. The increased load resulted in a decrease in the ratio of standing phase to ensure physical stability. The valgus group showed a trend of increasing the stability of their center of mass with increasing load, through higher braking power in the early standing phase. Conclusion : In conclusion, although there was no statistical difference in biomechanical variables according to the mechanical alignment of the lower limbs, the varus group showed a more irregular walking pattern with a Material handling than the valgus group, partially proving the association between lower limb alignment and walking with a Material handling.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권5호
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• pp.470-478
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• 2007

The purpose of this study was to investigate the clinical, biomechanical, and histologic changes in new distraction osteogenesis(DO) technique combined with a compression stimulation in accordance to different compression-distraction force ratio. 23 adult male rabbits underwent open-osteotomy at the mandibular body area and a external distraction device was applied. In the control group of 8 rabbits, only a 8 mm of distraction was performed by conventional DO technique. In an experimental group of 15 rabbits, a distraction followed by a compression force was performed according to the ratio of compression-distraction suggested by authors. The rate of experimental group I was set up as a 2 mm compression versus 10 mm distraction and the rate of experimental group II was set up as a 3 mm compression versus 11 mm distraction. All the rabbits were sacrificed for a gross finding, biomechanical, histomorphometric and histologic findings at the time of 55 days from the operation day. The results were as follows: 1. On the gross findings, because all rabbits had a sufficient healing time, every distracted new bone had good bone quality and we could not find any difference among all three groups. 2. In the histologic findings, rapid bone maturation(wide lamellar bone formation in the cancellous and cortical bone areas) was observed in two experimental groups compared to the control group. 3. On the bone density tests, the experimental group II showed higher bone density than the other experimental group and control group(control group-$0,2906g/cm^2$, experimental group I-$0.2961g/cm^2$, experimental group II-$0.3328g/cm^2$). 4. On the biomechanical tests, the experimental group II had significantly higher bone microhardness than the other experimental group and control group(control group-252.7 MPa, experimental group I-263.5 MPa, experimental group II-426.0 MPa). 5. On the microhardness tests, when we compared the hardness ratio of distracted bone versus normal bone, we could find experimental group II had significantly higher hardness ratio than the other experimental group and control group(control group-0.47, experimental group I-0.575, experimental group II-0.80). From this study, we could deduce that the modified distraction osteogenesis method with a compression stimulation might improve the quality of bone regeneration and shorten the consolidation period in comparison with conventional distraction osteogenesis techniques.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.907-908
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• 2012

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1996년도 춘계학술대회논문집
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• pp.291-300
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• 1996

This study is to determine the biomechanical characteristics of Korean. Male 58 and Female 54 were participated for the measurement which was performed by immersion method and reaction board method. Body parts were head with neck, trunk, upper arm, forearm, hand, thigh, leg, and foot. Their volumes were measures by immersion method. Their weight were determined by using Dempster(1995), Drills and Contini(1969) density data. Each center of body part weight were determined by specific posture on the reaction board. The postures were asked to the subject forearm- lifted posture, total let- lifted posture, foot-lifted posture. According to each posture, the center of each part were calculated.

• 대한정형외과 초음파학회지
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• 제2권2호
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• pp.94-98
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• 2009

침술은 중국에서 3,000년 이상의 기원을 가진 가장 대중적인 보완대체의학 치료 방법으로 전세계적에서 널리 시행되고 있다. 초음파는 교육과 연구목적, 신경과 늑막과 같은 위험한 구조 주위 경혈에 침술을 시행할 때 도움이 된다. 또한 초음파는 조직에서 침 수기의 생 기계적 효과를 평가하는 데 이상적인 영상 검사로 조직 형태와 생 기계적 정보의 영상을 제공하는 특징적 장점을 가지고 있다. 탄성영상은 내부 혹은 외부에서 발생하는 기계적 자극에 의한 조직의 기계적 성질 혹은 반응을 정량화 할 수 있다. 그러므로 초음파와 탄성영상의 결합은 침술에 의한 인체 결합조직 구조의 동적변화를 정량적으로 평가할 수 있다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1471-1472
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• 2008

To analyze biomechanical effects of various types of menisectomy in the knee joint, the contact area and pressure distribution of intact the knee joint and the operated by various menisectomies were studied by using finite element method their results are compared with each other. In this study, the femur, the tibia, the articular cartilage and the menisci were three dimensionally reconstructed using MR Images of healthy knee joint in full extension of 26 years old male. Also, three dimensional finite element model of the knee joint was constructed including the models of ligaments and tendons on the reconstructed three dimensional model. Bones were considered to be rigid, articular cartilage and menisci were considered as homogeneous, isotropic and linearly elastic materials and ligaments and tendons were modeled as hyperelastic materials. Based on the results, the effects of various types of menisectomy on the knee joints are clearly elucidated.

• 대한의용생체공학회:의공학회지
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• 제25권1호
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• pp.27-32
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• 2004

본 논문에서는 골다공증성 척추압박골절에 대한 척추성형술시 골강화제인 PMMA 주입방법을 제안하였다. 척추성형술의 정량적 분석을 위해서는 유한요소해석을 사용하였으며 1m간격의 척추체 CT를 바탕으로 보다 정교한 척추체 모델을 제시함으로써, 단순화된 척추의 기하학적 형상과 간단한 재료 물성치를 사용하는 기존의 연구의 한계를 극복하고자 하였다. 본 연구 결과를 토대로 추체내 망상골에 주입되는 PMMA의 주입형태, 주입위치를 정량적으로 평가하여 이상적인 수술방법을 제시하였다. PMMA의 구입위치는 망상골의 앞쪽-위쪽에 많은 양이 집중하여 주입되었을 때, 가장 효율적으로 추체를 보완해 주는 것으로 나타났다.

• The Journal of Advanced Prosthodontics
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• 제14권3호
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• pp.182-202
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• 2022

PURPOSE. The aim of this study is to summarize various biomechanical aspects in evaluating the long-term stability of dental implants based on finite element method (FEM). MATERIALS AND METHODS. A comprehensive search was performed among published studies over the last 20 years in three databases; PubMed, Scopus, and Google Scholar. The studies are arranged in a comparative table based on their publication date. Also, the variety of modeling is shown in the form of graphs and tables. Various aspects of the studies conducted were discussed here. RESULTS. By reviewing the titles and abstracts, 9 main categories were extracted and discussed as follows: implant materials, the focus of the study on bone or implant as well as the interface area, type of loading, element shape, parts of the model, boundary conditions, failure criteria, statistical analysis, and experimental tests performed to validate the results. It was found that most of the studied articles contain a model of the jaw bone (cortical and cancellous bone). The material properties were generally derived from the literature. Approximately 43% of the studies attempted to examine the implant and surrounding bone simultaneously. Almost 42% of the studies performed experimental tests to validate the modeling. CONCLUSION. Based on the results of the studies reviewed, there is no "optimal" design guideline, but more reliable design of implant is possible. This review study can be a starting point for more detailed investigations of dental implant longevity.

• 대한의용생체공학회:의공학회지
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• 제24권6호
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• pp.515-522
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• 2003

인두는 구강과 식도, 비강과 폐의 중간에서 능동적으로 구강을 통해 섭취되는 음식물과 비강을 통해 흡입되는 공기의 통로역할을 하는 주요한 기관이다. 본 연구는 유한요소기법을 이용한 인두의 3차원 구조의 재구성 과정을 거쳐 인두의 생체역학모델을 구현하였으며, 연하곤란환자의 인두근육의 주요부분에 대한 구조적 변형특성을 3가지로 분류하여 유한요소기법을 이용하여 인두내의 압력에 대한 형상의 변형을 관찰 후 최적화 과정을 거쳐 각 부분에서의 추정 압력 구배를 측정하여 연하과정에서 내부에 생성되는 압력의 연속적인 압력분포를 추정하였다. CT에 의한 인두의 변형 형상을 추정하여 임의 압력에 의한 인두구조의 변형 형상을 유한요소 해석에 의해 계산한 후 비교하여 실제 인두강 내에 형성되는 압력을 추정하였다. 재료적 특성은 인두의 기능이상 시 근조직경화가 발생, 즉 stiffness 가 증가하는 것으로 가정하여 응력-변형률 관계에 있어서 각각 $25\%,\;50\%,\;75\%$씩 증가시켜 분석하였다. 이러한 인두의 생체역학모델은 인두기능장애를 가진 환자의 치료 계획 수립에 도움이 되는 유용한 자료를 제공 할 것으로 생각된다.