• Journal of International Society for Simulation Surgery
• /
• 제2권2호
• /
• pp.80-82
• /
• 2015

The mandibuloplasty for the facial aesthetic reason has been the one of the most popular procedures in aesthetic facial bone surgery in East Asia. Most East Asian women prefer smaller-looking and smooth-shaped facial contour. Prominent mandible angle which are common in Asia would be the main problem for smooth facial contour. In addition, recently, the mandibular body and broad chin shape also are known to be remodeled in order to get the ideal smooth facial shape. However, mandibuloplasty is not that easy to cut because many patients has inward mandibular angle and the visual field in operation is limited. The aim of this trial is to try to provide the prefabricated cutting guide for the symmetric and appropriate mandibuloplasty with the surgeons. Preoperative computed tomography(CT) data were processed for the patient and computer simulation model was produced. Then, mandibuloplasty was done on the computer simulation screen. Based on this data, customized cutting guide was made. This prefabricated cutting guide was used in real mandibuloplasty bilaterally. Premade cutting guide for the mandibuloplasty based on the computer simulation turned out to be very successful in this patient. Individualized approach for each patient could be an ideal way to manage the patients in near future.

• 한국수소및신에너지학회논문집
• /
• 제16권3호
• /
• pp.253-261
• /
• 2005

석유 연료 고갈 해결 및 온실 효과 가스 배풀 저감을 위한 방안으로 제시되는 수소는 다양한 에너지 저장체로 사용되어 질 수 있으나 안전성에 대한 연구가 요구되어진다. 따라서, 일반적인 저장 형태인 고압 저장 탱크에서 누출이 되었을 경우 분사되는 수소의 거동에 대한 연구가 이루어져야하며 이를 바탕으로 한 보완책이 제시되어야 한다. 이번 연구에서는 누설 시 확산되는 수소의 밀도를 실제 거동과 유사한 3차원 컴퓨터 영상장으로 합성한 후 ART(algebraic reconstruction technique) 및 MART(multiplicative ART)를 기반으로 한 3차원 디지털 스페클 토모그래피 기법을 개발하여 재건하고 분석하였다.

• 대한치과의사협회지
• /
• 제52권1호
• /
• pp.8-16
• /
• 2014

The introduction of cone-beam computed tomography(CBCT) and computer software in orthodontics has allowed orthodontists to provide more accurate diagnosis and treatment. The most common use of CBCT imaging allows orthodontists to visualize the precise position of supernumerary or impacted teeth, especially impacted canines. In doing so, the exact angulation of impaction and proximity of adjacent roots can be evaluated by orthodontists, allowing them to choose vector forces for tooth movement while minimizing root resorption. Even though 2-dimensional panoramic images can be used to view the position of the impacted canines, they have limitations because it is not possible to evaluate the impacted tooth position 3-dimensionally. An accurate knowledge of root position improves the determination of success in orthodontic treatment. Nowadays, considering the fast pace of technological development, a combination of intraoral scanning, digital setups, custommade brackets and wires, and indirect bonding may soon become the orthodontic standard. In this paper, this will be discussed along with the digital models.

• Journal of International Society for Simulation Surgery
• /
• 제1권1호
• /
• pp.16-18
• /
• 2014

The orbit has a very special anatomical structure. The complex anatomical structure should be restored when we encounter the patient with orbital wall fracture. Unless these specific anatomy were reconstructed well, the patient should suffer from various complications such enophthalmos, diplopia or orbital deformity. In addition, because the patient has a his own specific orbital shape, individualized approach will be necessary. The aim of this trial is to try to restore the original orbit anatomy as possible based on the mirrored three dimensional CT images based on the computer simulation. Preoperative computed tomography (CT) data were processed for the patient and a rapid prototyping (RP) model was produced. At the same time, the uninjured side was mirrored and superimposed onto the traumatized side, to create a mirror-image of the RP model. In order to restore the missing skipped images between the cuts of CT data because of the thinness of the orbital walls, we manipulated the DICOM data for imaging the original orbital contour using the preoperatively manufactured mirror-image of the RP model. And we fabricated Titanium-Medpor to reconstruct three-dimensional orbital structure intraoperatively. This prefabricated Titanium-Medpor was then inserted onto the defected orbital wall and fixed. Three dimensional approach based on the computer simulation turned out to be very successful in this patient. Individualized approach for each patient could be an ideal way to manage the traumatic patients in near future.

• 한국의류산업학회지
• /
• 제11권5호
• /
• pp.779-787
• /
• 2009

The purpose of this study was to classify the head shape for the apparel industry and to suggest standard head model for korean women. The 23 measurement items of 891 females, aged more than 18 years were used to analysis by statistical methods. Factor analysis, cluster analysis and duncan test were performed using these data. Through factor analysis, 5 factors were extracted upon factor scores and those factors comprised 68.76% for the total variances. 5 clusters as their head and face shape were categorized. We decided for the type 3 to standard head shape. 24 participants were measured using computed tomography(CT). The measured data of skin and skeleton and the standard head shapes were illustrated.

• 한국분말재료학회지
• /
• 제28권3호
• /
• pp.208-215
• /
• 2021

Metal three-dimensional (3D) printing is an important emerging processing method in powder metallurgy. There are many successful applications of additive manufacturing. However, processing parameters such as laser power and scan speed must be manually optimized despite the development of artificial intelligence. Automatic calibration using information in an additive manufacturing database is desirable. In this study, 15 commercial pure titanium samples are processed under different conditions, and the 3D pore structures are characterized by X-ray tomography. These samples are easily classified into three categories, unmelted, well melted, or overmelted, depending on the laser energy density. Using more than 10,000 projected images for each category, convolutional neural networks are applied, and almost perfect classification of these samples is obtained. This result demonstrates that machine learning methods based on X-ray tomography can be helpful to automatically identify more suitable processing parameters.

• 한국통신학회논문지
• /
• 제38C권10호
• /
• pp.887-895
• /
• 2013

골 전이 암은 여러 장기에 생긴 암이 질병이 경과함에 따라 뼈로 옮아가는 것으로서, 암 환자에게서 주로 발생하는 합병증 중 하나이다. 골 전이는 골 용해성 전이와 골 형성성 전이로 구분되며, CT에서 골 전이의 진단은 임상적으로 매우 유용할 수 있으나, 많은 판독건수로 인하여 중요한 병변이 간과되는 경우가 많고, 이를 통해 골 전이 암을 조기에 진단하지 못하는 경우가 발생할 수 있다. 이에 본 논문에서는 흉부 CT의 단층 영상들을 3차원 볼륨 데이터로 구성하여 3차원 영상처리 알고리즘을 적용하여 골 전이 병변을 검출하고 3차원 가시화를 수행하였으며, 총 10개 데이터에 대해 민감도를 측정한 결과, 골 형성성 병변이 평균 94.1%, 골 용해성 병변이 평균 90.0%의 값을 나타내어 골 전이 진단에서의 활용에 대한 높은 가능성과 잠재적인 유용성을 확인할 수 있었다.

• 대한치과교정학회지
• /
• 제46권1호
• /
• pp.13-19
• /
• 2016

Objective: The aim of this study was to compare the accuracy of Bolton analysis obtained from digital models scanned with the Ortho Insight three-dimensional (3D) laser scanner system to those obtained from cone-beam computed tomography (CBCT) images and traditional plaster models. Methods: CBCT scans and plaster models were obtained from 50 patients. Plaster models were scanned using the Ortho Insight 3D laser scanner; Bolton ratios were calculated with its software. CBCT scans were imported and analyzed using AVIZO software. Plaster models were measured with a digital caliper. Data were analyzed with descriptive statistics and the intraclass correlation coefficient (ICC). Results: Anterior and overall Bolton ratios obtained by the three different modalities exhibited excellent agreement (> 0.970). The mean differences between the scanned digital models and physical models and between the CBCT images and scanned digital models for overall Bolton ratios were $0.41{\pm}0.305%$ and $0.45{\pm}0.456%$, respectively; for anterior Bolton ratios, $0.59{\pm}0.520%$ and $1.01{\pm}0.780%$, respectively. ICC results showed that intraexaminer error reliability was generally excellent (> 0.858 for all three diagnostic modalities), with < 1.45% discrepancy in the Bolton analysis. Conclusions: Laser scanned digital models are highly accurate compared to physical models and CBCT scans for assessing the spatial relationships of dental arches for orthodontic diagnosis.

• Applied Microscopy
• /
• 제44권3호
• /
• pp.83-87
• /
• 2014

Electron tomography (ET) is a useful tool to investigate three-dimensional details based on virtual slices of relative thick specimen, and it requires complicated procedures consisted of image acquisition steps and image processing steps with computer program. Although the complicated step, this technique allows us to overcome some limitations of conventional transmission electron microscopy: (1) overlapping of information in the ultrathin section covering from 30 nm to 90 nm when we observe very small structures, (2) fragmentation of the information when we study larger structures over 100 nm. There are remarkable biological findings with ET, especially in the field of neuroscience, although it is not popular yet. Understanding of behavior of synaptic vesicle, active zone, pooling and fusion in the presynaptic terminal have been enhanced thanks to ET. Some sophisticated models of postsynaptic density with ET and immune labeling are introduced recently. In this review, we introduce principles, practical steps of ET and some recent researches in synapse biology.

• Journal of Korean Neurosurgical Society
• /
• 제56권1호
• /
• pp.16-20
• /
• 2014

Objective : Two-dimensional fluoroscopy-based computerized navigation for the placement of pedicle screws offers the advantage of using stored patient-specific imaging data in providing real-time guidance during screw placement. The study aimed to describe the accuracy and reliability of a fluoroscopy-based navigation system for pedicle screw insertion. Methods : A total of 477 pedicle screws were inserted in the lower back of 96 consecutive patients between October 2007 and June 2012 using fluoroscopy-based computer-assisted surgery. The accuracy of screw placement was evaluated using a sophisticated computed tomography protocol. Results : Of the 477 pedicle screws, 461 (96.7%) were judged to be inserted correctly. Frank screw misplacement [16 screws (3.3%)] was observed in 15 patients. Of these, 8 were classified as minimally misplaced (${\leq}2mm$); 3, as moderately misplaced (2.1-4 mm); and 5, as severely misplaced (>4 mm). No complications, including nerve root injury, cerebrospinal fluid leakage, or internal organ injury, were observed in any of the patients. Conclusion : The accuracy of pedicle screw placement using a fluoroscopy-based computer navigation system was observed to be superior to that obtained with conventional techniques.