• 제목/요약/키워드: shape reconstruction

검색결과 468건 처리시간 0.031초

광범위 종양절제술 후 발생한 하악 결손의 재건 : 결손부위에 따른 비골 유리 피판의 다양한 디자인 (Reconstruction of Mandible Defect after Tumor Ablation Surgery : Versatility of Fibular Free Flap Design)

  • 설철환;이영대;탁관철;유대현
    • 대한두경부종양학회지
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    • 제21권2호
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    • pp.190-195
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    • 2005
  • Background and Objectives: Fibula is the flap of choice for reconstruction of wide mandible defects after tumor ablation surgery. In mandible reconstruction, restoring the mandible frame to provide mandibular contour and dental arch while restoring masticatory function are important. Even though vascularized fibula can be osteotomized freely, proper design and flap insetting is not easy because of its three dimensional structure and difference in design according to the defect sites. We reviewed patients who underwent mandible reconstruction with fibular flaps according to the defect sites and suggest proper modification methods of fibular flap according to the various defects sites after tumor ablation surgery. Materials and Methods: Twelve consecutive mandible reconstruction with fibular free flaps were performed for defects after tumor ablation surgery. Patients were classified into 4 groups according to the type of mandibular defect(Group 1 : defect on central segment including symphysis, Group 2 : defect on lateral segment(with or without central segment) confined to body, Group 3 : defect on body and ascending ramus that does not include the condyle, Group 4 : defect including the condyle). Results: We suggest different modification methods of fibular free flap for each patient group. Group 1, 3 ; contour by using multiple closing wedge osteotomy. Group 2 ; single or double barrel reconstruction without wedge osteotomy. Group 4 ; contour using single or multiple wedge osteotomy and condylar reconstruction with costochondral graft. Conclusion: Fibular free flaps can be contoured to any desired shape after multiple osteotomies to restore various mandibular defects. It is a reliable and versatile method for reconstruction of mandibular defects after tumor ablation surgery.

Fiber optic shape sensor system for a morphing wing trailing edge

  • Ciminello, Monica;Ameduri, Salvatore;Concilio, Antonio;Dimino, Ignazio;Bettini, Paolo
    • Smart Structures and Systems
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    • 제20권4호
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    • pp.441-450
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    • 2017
  • The objective of this work is to present a conceptual design and the modelling of a distributed sensor system based on fiber optic devices (Fiber Bragg Grating, FBG), aimed at measuring span-wise and chord-wise variations of an adaptive (morphing) trailing edge. The network is made of two different integrated solutions for revealing deformations of the reference morphing structure. Strains are confined to typical values along the span (length) but they are expected to overcome standard ranges along the chord (width), up to almost 10%. In this case, suitable architectures may introduce proper modulations to keep the measured deformation low while preserving the information content. In the current paper, the designed monitoring system combines the use of a span-wise fiber reinforced patch with a chord-wise sliding beam. The two elements make up a closed grid, allowing the reconstruction of the complete deformed shape under the acceptable assumption that the transformation refers to regular geometry variations. Herein, the design logic and some integration issues are reported. Preliminary experimental test results are finally presented.

초점화소 탐색시간의 최소화를 위한 검색영역 결정기법 (Shape Adaptive Searching Technique for Finding Focused Pixels)

  • 최대성;송필재;김현태;한헌수
    • 한국정밀공학회지
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    • 제19권2호
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    • pp.151-159
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    • 2002
  • The method of accumulating a sequence of focused images is usually used for reconstruction of 3D object\\`s shape. To acquire a focused image, the conventional methods must calculate the focus measures of all pixels resulting in a long measurement time. This paper proposes a new method of reducing the computation time spent for deciding the focused pixels in the input image, which predicts the area in the image to calculate the focus measure based on a priori information on the object to be measured. The proposed algorithm estimates the area to consider in the next measurement based on the focused area in the present measurement. As the focus measure, Laplacian measure was used in this paper and the experiments have shown that the preposed algorithm may significantly reduce the calculation time. Although, as implied, this algorithm can be applied to only simple objects at this stage, advanced representation schemes will eliminate the restrictions on application domain.

내시경과 선택적 도뇨관 풍선을 이용한 안와하벽복원술 (Orbital Floor Reconstruction Using Endoscope and Selected Urethral Balloon Catheter)

  • 최환준;이주철;이형교;김준혁
    • Archives of Plastic Surgery
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    • 제38권1호
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    • pp.35-42
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    • 2011
  • Purpose: Blow-out fractures can be reduced using various methods. The orbital reconstruction technique using a balloon under endoscopic control has advantages over other methods. However, this method has some problems too, such as postoperative follow-up, management of the balloon catheter, and reduction of the posterior orbital floor. Thus, we developed a simple, effective method for orbital floor reduction that involves molding and shaping the antral balloon catheter. Methods: A 0, 30, or $70^{\circ}$, 4-mm endoscope was placed though a two-point, 5-mm maxillary antrostomy. The balloon catheter is placed directly at the orbital apex to reconstruct the anterior shelf (spherical shape), while it is turned in a U-shape towards the anterior maxilla for the posterior shelf (elliptical shape). Orbital floor defects, compound or comminuted fractures are reconstructed with alloplastic materials through an open lid incision under the endoscopic control. Results: This technique was applied to ten patients with orbital floor fractures: five anterior shelf and five posterior shelf fracture, respectively. Four of the patients had zygomatico-orbital fractures, while the rest had isolated orbital floor fractures. Two patients were given porous polyethylene implants Synpor$^{(R)}$) and three underwent reconstruction with a resorbable mesh plate. No complication associated with this technique was identified. Conclusion: The freestyle placement and selection of a urinary balloon catheter under endoscopic control and the preoperative estimation of the volume enhanced the stabilization of the orbital contour. This method improves the adaptation of the orbital floor without the risk of injuring the surrounding orbital contents, dissecting blindly, or using sharp traction. One drawback of this method is the patient's discomfort from the catheter during treatment.

3차원 형상 복원을 위한 재귀적 오차 성분 보정 방법 (Recursive Error-Component Correcting Method for 3D Shape Reconstruction)

  • 고성식
    • 한국정보통신학회논문지
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    • 제21권10호
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    • pp.1923-1928
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    • 2017
  • 본 연구는 행렬인수분해 기반으로 3차원 형상의 복원을 위한 오차 보정에 관한 것입니다. 기존 행렬인수분해 기반 오차 보정 방법은 전역적인 최적화로 인해 보정에 한계가 있습니다. 따라서 본 논문에서는 전역적 접근 대신 3차원 복원 형상의 주요 오차 영향 인자를 찾아 보정하는 새로운 방법을 제시하였습니다. 우리는 오차 영향 인자를 2차원 재 투영 편차 공간에서 정의하고 그 오차 성분을 직접 보정합니다. 그리고 일련의 과정을 재귀적으로 반복 적용함으로서 오차 보정 성능을 개선시킬 수 있습니다. 이러한 접근 방법은 어떤 기하학적 정보에 의존하지 않고 영향도가 가장 큰 오차 성분 중심으로 제어하기 때문에 잡음에 장점을 가지고 있습니다. 제안한 알고리즘 성능 평가는 합성과 실제 영상 프레임으로 시뮬레이션하여 잡음에 강인한 특성을 증명했습니다.

고차 통계 초점 척도를 이용한 3D 모델 복원 알고리즘 (3D Model Reconstruction Algorithm Using a Focus Measure Based on Higher Order Statistics)

  • 이주현;윤현주;한규필
    • 한국멀티미디어학회논문지
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    • 제16권1호
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    • pp.11-18
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    • 2013
  • 본 논문에서는 정확한 깊이를 추출하기 위해 고차 통계기반 초점 척도를 이용한 SFF(shape from focus) 알고리즘을 제시한다. 기존의 SFF기반 3차원 깊이 복원 기법들은 초점 척도로 SML(sum of modified Laplacian)을 사용하기 때문에, 성능이 영상의 특성에 크게 의존하여 초점이 정밀하거나 질감이 풍부한 영상에서만 효율적이다. 그러므로, 본 논문에서는 비교적 질감과 초점이 빈약한 영상에서도 초점 값을 추출할 수 있도록 고차 통계(HOS:higher order statistics)를 이용한 알고리즘을 제안한다. 이 초점 척도에 의해 초점 영역 맵이 생성되고 국부적으로 최적의 초점 값을 갖는 화소를 추출하기 위해 영역개선, 세선화, 모서리 검출과정이 순서적으로 적용된다. 최종적으로 추출된 점에 대해서 Delaunay 삼각화를 사용하여 3차원 모델정보를 생성한다.

직각 Z-절골술을 이용한 거대 두개골 결손의 재건 (Reconstruction of Large Skull Defect Using Right-Angled Zigzag Osteotomy)

  • 이기영;백혜원;변준희
    • Archives of Plastic Surgery
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    • 제34권5호
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    • pp.667-670
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    • 2007
  • Purpose: Among the materials for cranioplasty, autogenous bone is ideal because it is less susceptible to infection and has lower rates of subsequent exposure. However, the procedure is technically demanding to perform and requires a donor site. Disadvantages further exist when the defect is large and there are attendant limitations in donor site. The authors present their experience with reconstruction of large skull defect using right-angled zigzag osteotomized outer table of autogenous calvarial bone, overcoming the limitation in donor site. Methods: From 2000 to 2006, 9 patients were retrospectively reviewed, who had undergone reconstruction with right angled zigzag osteotomized outer table of autogenous calvarial bone. Results: Aesthetically satisfactory skull shape was achieved. Major complications of infection, hematoma, plate exposure, and donor site complications of dural tear with bleeding, cerebrospinal fluid leak, and meningitis were not seen. One patient had delayed wound healing and was successfully managed conservatively. Conclusion: Autogenous bone is the material of choice for cranioplasty, especially in complicated cases. Right angled zigzag osteotomy is a useful method in reconstruction of large skull defects with less donor site morbidity.

토끼 기관의 재건에 이용된 혈행성 연골막 피판의 연골생성능 (Chondrogenic Activity of Vascularized Perichondrial Flap for Rabbit Tracheal Reconstruction)

  • 김은서;최은창;김영호;홍원표;김영덕
    • 대한기관식도과학회지
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    • 제2권1호
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    • pp.46-56
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    • 1996
  • Perichondrium is generally used for reconstruction of airway and successful regeneration of cartilage framework using perichondrium are reported by several authors. It has many advantages for airway reconstruction. It can maintain the stable framework and it has higher flexibility so it's easy to design according to the shape of defects. It resist strongly against infection process. Its airtightness and rapid mucosalization enables to predict good postoperative recovery and results. To investigate the differences in cartilage regeneration between avascular and vascularized perichondrial flap, this study was designed with vascularized flaps composed of vascularized perichondrium and central auricular artery and vein. Morphologic study was performed to determine the fate of the grafted perichondrium at regular intervals using light microscopy with H & E stain. Chondrogenic potential and formation of cartilaginous plate of experimental group was superior than in the control group. Grafted perichondrium was fed by consistent feeding vessel. At 6 weeks, the regenerated cartilage could hardly be distinguished form the normal cartilage framework but in control group, regenerated cartilaginous tissue was generally immature in same period. In conclusion, this study indicated that consistent vasculature to grafed tissue is the essential factor for successful reconstruction of cartilaginous framework.

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고종 36년(1899) 남관왕묘의 중건과 건축 특성 연구 (A Study on the Architectural Characteristic of Nam-kwan-wang-myo and it's Reconstruction)

  • 권준형
    • 건축역사연구
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    • 제22권4호
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    • pp.73-82
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    • 2013
  • This study aims to find architectural characteristic of Nam-kwan-wang-myo as known as Nam-myo, Especially focusing on difference between before and after it's reconstruction in 1899. Nam-kwan-wang-myo is a shrine for Kwan-woo who was warlord in ancient china. Belief of Kwan-Woo was introduced to Korea in Japanese invasion of 1592 and the shrine was built in 1598. Belief of Kwan-Woo diffused for the late Joseon, during the reign of Gojong, many people have faith in Kwan-Woo including the king. There was four Kwan-wang-myo around the Hanyang at that time. In 1899 a fire of unknown cause broke out at Nam-kwan-wang-myo, so the main buildings burned down. The king instructed reconstruction of the shrine even though there was in financial difficulties, it had done in the midst of a national crisis. The buildings almost restored as before. The buildings in the shrine has strong characteristics of Chinese architecture because it made by people of the Ming dynasty. Two side-by-side roofs, accumulated brick exterior are important architectural feature, but also all the buildings in the mail hall area Surrounded by the closed-connected fence is hard to find examples in Korea traditional architecture. And Nam-kwan-wang-myo just had maintained architectural characteristics including layout of buildings, shape of the each building until it's reconstruction(1899).

Neurodevelopmental Problems in Non-Syndromic Craniosynostosis

  • Shim, Kyu-Won;Park, Eun-Kyung;Kim, Ju-Seong;Kim, Yong-Oock;Kim, Dong-Seok
    • Journal of Korean Neurosurgical Society
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    • 제59권3호
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    • pp.242-246
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    • 2016
  • Craniosynostosis is the premature fusion of calvarial sutures, resulting in deformed craniofacial appearance. Hence, for a long time, it has been considered an aesthetic disorder. Fused sutures restrict growth adjacent to the suture, but compensatory skull growth occurs to accommodate the growing brain. The primary goal for the management of this craniofacial deformity has been to release the constricted skull and reform the distorted shape of the skull vault. However, the intellectual and behavioral prognosis of affected children has also been taken into consideration since the beginning of the modern era of surgical management of craniosynostosis. A growing body of literature indicates that extensive surgery, such as the whole-vault cranioplasty approach, would result in better outcomes. In addition, the age at treatment is becoming a major concern for optimal outcome in terms of cosmetic results as well as neurodevelopment. This review will discuss major concerns regarding neurodevelopmental issues and related factors.