• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.519-520
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• 2006

The aim of this study was biomechanical analysis of shelf operation in patients with dysplastic hip joint by finite element contact analysis. Two dimensional CT images were used to construct the finite element models to analyze the contact pressure, and the 3D expansion of the Ninomiya's method was used in the calculation of the resultant force in the hip joint. The surgery recovered the center-edge angles to the normal anatomical range and increased the contact areas in two patients. The maximum contact pressures and von-mises stresses were decreased. The present study provides the biomechanical guideline of optimal surgical parameters to maximize the surgical efficiency and the clinical outcomes in dysplastic hip joint using the shelf operation.

• 산업공학
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• 제24권4호
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• pp.274-280
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• 2011

Delayed access to surgery may lead to deterioration in the patient condition, poor clinical outcomes, increase in the probability of emergency admission, or even death. The purpose of this work is to decide the number of patients selected from a waiting list and to schedule them in accordance with the operating room capacity in the next period. We formulate the problem as an infinite horizon Markov Decision Process (MDP), which attempts to strike a balance between the patient waiting times and overtime works. Structural properties of the proposed model are investigated to facilitate the solution procedure. The proposed procedure modifies the conventional value iteration method along with the binary search technique. An example of the optimal policy is provided, and computational results are given to show that the proposed procedure improves computational efficiency.

• 지역연구
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• 제34권2호
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• pp.3-19
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• 2018

본 연구의 목적은 우리나라 의료자원의 임상적 성과에 대한 효율성을 종단적으로 관찰하는 데 있다. 이를 위하여, 2006년부터 2013년까지 우리나라 16개 시도의 연령 표준화 사망률을 산출변수로, 의사, 전문의, 수술, 의료기관, 상급종합병원비율, 만성질환 진료 실인원, 만성질환 내원일 수를 투입변수로 정하고, 이를 이용한 의료성과 및 의료자원에 대한 집계자료를 구축하여 패널확률프론티어모형을 분석방법으로 적용하였다. 또한 시도별 인구사회학적, 사회경제적 특성, 의료자원 분포 특성 변수인 실업률, 노인인구비율, 1인당 GRDP, 종합병원 대비 상급종합병원 비율이 패널확률프론티어모형 분석 결과를 바탕으로 도출된 기술적 효율성에 미치는 영향을 추가적으로 살펴보았다. 이때 오차항의 이분산과 자기상관을 고려한 패널모형을 적용하였다. 주요 분석 결과는 다음과 같다. 첫째, 임상적 성과에 대해서는 의사, 전문의와 같은 공급 측면의 인적 의료자원과 단위 인구당 만성질환 진료 실인원과 같은 수요 측면의 요인이 각각 유의한 영향력을 미치는 것으로 나타났다. 둘째, 투입요소 시변 마모 모형 적용 결과 각 투입요소별 기술 결합 효율성 추정치는 임상적 성과 효율성이 지역별로 59~70%로 나타났다. 셋째. 임상적 성과에 영향을 미치는 투입요소의 기술적 효율성 추정치는 분석기간 동안 모든 지역에서 미세하게 증가하는 추세가 도출된 반면, 증가 추세는 미세하게 감소하였다. 넷째, 지역의 노인인구비율과 1인당 GRDP는 기술적 효율성 수치에 유의한 정(+)적 영향력을 미치는 것으로 나타났다. 지역별 각 효율성의 차이는 투입요소인 의료자원의 지역별 차이와 이의 결합과 지역의 인구사회학적, 사회경제적 특성 등에 기인한 것으로서, 지역별로 임상적 성과에 영향을 미치는 의료자원의 공급 편중과 수요의 접근성 차이, 인구구조와 경제적 차이가 복합적으로 작용함에 따른 기술적 효율성 차이가 다르게 나타나고 있음을 보였다는 점에 본 연구의 의의가 있다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제39권3호
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• pp.112-119
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• 2013

Objectives: This study investigated the question of whether adenoviral magnetofection can be a suitable method for increasing the efficacy of gene delivery into bone marrow stromal cell (BMSC) and for generation of a high level of bone morphogenic protein (BMP) secretion at a minimized viral titer. Materials and Methods: Primary BMSCs were isolated from C57BL6 mice and transduced with adenoviral vectors encoding ${\beta}$ galactosidase or BMP2 and BMP7. The level of BMP secretion, activity of osteoblast differentiation, and cell viability of magnetofection were measured and compared with those of the control group. Results: The expression level of ${\beta}$ galactosidase showed that the cell transduction efficiency of AdLacZ increased according to the increased amount of magnetic nanoparticles. No change in cell viability was observed after magnetofection with 2 ${\mu}L$ of magnetic nanoparticle. Secretion of BMP2 or BMP7 was accelerated after transduction of AdBMP2 and 7 with magnetofection. AdBMP2 adenoviral magnetofection resulted in up to 7.2-fold higher secretion of BMP2, compared with conventional AdBMP2-transduced BMSCs. Magnetofection also induced a dramatic increase in secretion of BMP7 by up to 10-fold compared to the control. Use of only 1 multiplicity of infection (moi) of magnetofection with adenoviral transduction of AdBMP2 or AdBMP7 resulted in significantly higher transgene expression compared to 20 moi of conventional adenoviral transduction. Conclusion: Magnetic particle-mediated gene transudation is a highly efficient method of gene delivery to BMSCs. Magnetofection can lower the amount of viral particles while improving the efficacy of gene delivery.

• Asian Pacific Journal of Cancer Prevention
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• 제14권8호
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• pp.4871-4875
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• 2013

This meta-analysis was performed to evaluate and compare the outcomes of robotic gastrectomy (RG) and laparoscopic gastrectomy (LG) for treating gastric cancer. A systematic literature search was carried out using the PubMed database, Web of Knowledge, and the Cochrane Library database to obtain comparative studies assessing the safety and efficiency between RG and LG in May, 2013. Data of interest were analyzed by using of Review Manager version 5.2 software (Cochrane Collaboration). A fixed effects model or random effects model was applied according to heterogeneity. Seven papers reporting results that compared robotic gastrectomy with laparoscopic gastrectomy for gastric cancer were selected for this meta-analysis. Our metaanalysis included 2,235 patients with gastric cancer, of which 1,473 had undergone laparoscopic gastrectomy, and 762 had received robotic gastrectomy. Compared with laparoscopic gastrectomy, robotic gastrectomy was associated with longer operative time but less blood loss. There were no significant difference in terms of hospital stay, total postoperative complication rate, proximal margin, distal margin, numbers of harvested lymph nodes and mortality rate between robotic gastrectomy and laparoscopic gastrectomy. Our meta-analysis showed that robotic gastrectomy is a safe technique for treating gastric cancer that compares favorably with laparoscopic gastrectomy in short term outcomes. However, the long term outcomes between the two techniques need to be further examined.

• 대한핵의학회지
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• 제31권3호
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• pp.365-371
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• 1997

The aim of this study is to evaluate the efficiency of the pulmonary perfusion scan(Pp scan) in the experimental animal single lung transplantation. Eight left lung transplanted mongrel dogs were included in this study. The serial Pp scan with 111MBq $^{99m}TC-MAA$ were done at the periods of immediate postoperative period, POD 3 days, and POD 10-14 days and finally autopsy was done in each cases. The transplanted lung perfusion was analysed as a percentage radioactivity of trans planted/native lung(T/N) ratio. The Pp scan of a donor mongrel dog was used as a reference(left/right lung (T/N) ratio 85.2%). The average T/N ratio of all cases on immediate postoperative state(reperfusion injury) : 19.2%, three acute rejections. 12.6%, three bronchial dehiscences 6.1% and two pulmonary thromboses : 2.0%. Two cases showed moderate improvement of reperfusion injury as increasing the T/N ratio in POD 3 days Pp scan. The T/N ratio showed sequentially decreased in six cases. As a conclusion, the Pp scan could be a non-invasive method in the evaluation of the experimental one-lung transplanted mongrel dog.

• Journal of Korean Neurosurgical Society
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• 제41권2호
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• pp.105-110
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• 2007

Objective : This purpose of this study was to determine the clinical efficiency and applicability, and to analyze the radiologic findings of the anterior cervical approach using two synthetic cages for interbody fusion. Methods : A total of 41 patients with cervical diseases underwent anterior discectomy and interbody fusion with the PEEK $Solis^{TM}$ cage in 21 patients and the carbon composite $Osta-Pek^{TM}$ cage in 20 patients. Outcome assessment was done using Odom's criteria. Radiological assessment was performed with respect to subsidence, bony fusion and lordosis. The mean follow-up period was 13 months. Results : There were 34 [92.9%] successful cases. The average height of the disc space 12 months after surgery compared the height just after surgery was decreased over 3mm in 4 cases, indicating severe subsidence. The use of these synthetic cages have provided the increase in postoperative cervical lordosis. Conclusion : There were no significant differences between the $Solis^{TM}$ and $Osta-Pek^{TM}$ cages on clinical and radiologic outcomes. Both $Solis^{TM}$ and $Osta-Pek^{TM}$ cages showed low subsidences and complications associated with hardware with good clinical outcomes, high fusion rates, restored disc heights, and restored cervical lordosis.

• 구강회복응용과학지
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• 제31권2호
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• pp.158-168
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• 2015

본 증례는 상 하악 완전 무치악 환자에서 진단, 식립 그리고 보철물 제작에 디지털 방식을 활용하는 방법에 대해 제시하였다. 상악은 구개 부위, 하악은 기존 의치에 방사선 불투과성 마커를 부착한 후 구강스캔 및 CBCT 촬영을 시행하였다. 구강스캔 이미지와 CBCT 이미지를 중첩시켜 진단 및 수술가이드와 임시보철물을 제작하였다. 골유착 후에는 스캔바디를 이용한 구강스캔을 통해 최종보철물을 제작하였다. 임플란트를 이용한 전악수복에서 디지털 방식을 다양하게 활용하였으며 정확성과 환자의 불편감 최소화라는 목적에 만족할만한 결과를 얻었기에 이 증례를 보고하고자 한다.

• 전자공학회논문지
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• 제52권2호
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• pp.173-181
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• 2015

연구에서는 진단 및 수술 후 잔여병소의 검출을 위하여 방사선계수 방식의 무선 감마선 프로브를 개발하고, 교정선원과 팬텀을 이용하여 그 유용성을 평가 하였다. 반도체기반 방사선센서를 사용하여 프로브 설계 및 소형화 하였으며, 블루투스 원격통신 모듈을 사용하여 진단 및 검출 시스템의 무선화를 구현하였다. 또한 진단 및 수술 시 환부의 모니터링이 가능한 원격모니터링 시스템을 구현하였다. 개발된 프로브의 유용성 평가를 위해 교정선원 $^{57}Co$, $^{133}Ba$, $^{22}Na$, $^{137}Cs$과 닭 가슴살 팬텀을 사용하였다. 평가를 통해 감마선에 대한 프로브의 검출 반응성을 확인하였고, 감마선 세기에 따른 응답 선형성과 검출 방향성, 팬텀 내 선원 깊이에 따른 프로브의 검출효율을 평가를 통해 실증적인 임상에서의 적용 가능성을 확인하였다.

• Journal of Chest Surgery
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• 제27권7호
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• pp.610-616
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• 1994

Myasthenia gravis is a rare condition, affecting only 1/75000. It is characterized by weakness and fatigue of the voluntary muscles due to impaired neuromuscular transmission at the acetylcholine receptor site. It is probably caused by an autoimmune mechanism leading to reduction of the available nicotinic acetylcholine receptors at the neuromuscular junction. A relationship between the thymus and myasthenia gravis was suggested by Weigert in 1901, and Blalock was the first to report the efficiency of thymectomy in the treatment of myasthnia gravis in 1939. Since that time, thymectomy has become increasingly important in managing patients with myasthenia gravis. Fourteen patients with myasthenia gravis underwent thymectomy between September 1987 and March 1994 and got the following results; 1. The sex distribution was 10 females and 4 males with ages ranging from 15 to 51 years[mean, 34.8 years]. 2. Clinical manifestation of ocular symptoms were seen in all cases, dysphagia in 12[85.7%], extremity weakness in 11 [78.6 %], and dyspnea in 3 [21.4 %]. 3. According to the modified Osserman`s classification, 8 patients were in group IIb, 3 in IIa, 2 in I and 1 in IIc, respectively. 4. Histopathologic examination of the resected thymuses revealed hyperplasia in 8 patients, benign thymoma in 3, and malignant thymoma in 3. 5. There were no perioperative or immediate postoperative deaths but one patient died about two months after the thymectomy due to respiratory failure. 6. During the follow-up period, 11 patients [78.6 %] showed clinical improvement. Among them, 4 cases [28.6 %] showed complete remission, 3 [21.4 %] showed marked improvement, and 4 [28.6 %] showed subjective improvement. 7. Among the 8 patients with thymic hyperplasia, clinical improvement was noticed in 7 patients 5 %]. Among the 6 patients with thymoma, 4 patients [66.7 %] showed improvement.