• Korean Journal of Bronchoesophagology
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• v.17 no.1
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• pp.40-45
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• 2011

Background and Objectives Detailed information about the impacted esophageal foreign body is essential for safe extraction. Three dimensional reconstruction technique was applied to know shape, size and location of the simulative foreign bodies of stone, hyoid bone and endotracheal tube. Materials and Methods Submandibular gland stone, hyoid bone and endotracheal tube were used to simulate impacted foreign bodies. Axial CT, multi-planar reconstruction, volume of interest and virtual camera of Rapidia software were used to get information about the simulative foreign bodies from CT data. Shape and size were compared with the real materials. Exact locations were measured in appropriate modes of Rapidia. Results Shapes of the simulative foreign bodies matched well with the real materials. Size and location could be measured in various modes with some variable results. Conclusion 3D technique can be applied to get information about the simulative foreign bodies. This technique could be applied to the impacted esophageal foreign body.

• Archives of Craniofacial Surgery
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• v.19 no.2
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• pp.152-156
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• 2018

Mandibular defects lead to severe deformation and functional deficiency. Vascularized osteocutaneous tissue has been widely used to reconstruct the mandible. However, it is technically challenging to shape this type of grafts in such a manner that they resemble the configuration of the mandible. A 48-year-old female patient who underwent anterolateral thigh (ALT) flap coverage after a tongue cancer excision was diagnosed with a tumor recurrence during the follow-up. A wide excision mandibulectomy and mandibular reconstruction with an ALT flap and a titanium implant were performed. The prefabricated titanium implant was fixed to the condyle. Then, an ALT flap was harvested from the ipsilateral thigh and anastomosed. After confirming that the circulation of the flap was intact, the implant was fixed to the parasymphysis. On the radiograph taken after the surgery, the prosthesis was well positioned and overall facial shape was acceptable. There was no postoperative complication during the follow-up period, 1 year and 2 months. The prefabricated implant allows the restoration of facial symmetry without harvesting autologous bone and it is a safe and effective surgical option for mandibular reconstruction.

• Archives of Plastic Surgery
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• v.46 no.5
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• pp.480-483
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• 2019

Repairing surgical defects of the nose is still challenging due to its tridimensional shape and its aesthetic concern. Difficulty in reconstructing nasal subunits lies in their contour, skin texture and limited availability of adjacent skin. For lower nasal dorsum and supra-tip regions, we design a new combined local flap as existing local flaps may give disappointing results. This combination flap was performed on two patients for reconstruction of the lower nasal dorsum area after basal cell carcinoma excision. Size of the excision ranged from 20 to 25 mm diameter and safe margins were obtained. The defects were reconstructed with a local flap that combined a rotation nasal flank flap and a V-Y advancement nasolabial flap. Excision and reconstruction were performed in a one-stage surgery under intravenous sedation and local anesthesia. There were no postoperative complications and no flap loss occurred. Aesthetic and functional results after 6 months postoperatively were satisfying without modification of nasal shape. This flap is reliable and offers interesting functional and aesthetic outcomes. It can be considered as a new reconstruction alternative for supra-tip and lower nasal dorsum skin defects performed in a one-stage procedure under local anesthesia.

• Smart Structures and Systems
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• v.22 no.5
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• pp.621-630
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• 2018

Boundary effect and the noise robustness are the two crucial aspects which affect the effectiveness of the damage localization based on the mode shape measurements. To overcome the boundary effect problem and enhance the noise robustness in damage detection, a simple damage localization method is proposed based on the Singular Value Decomposition (SVD) for the mode shape of composite plates. In the proposed method, the boundary effect problem is addressed by the decomposition and reconstruction of mode shape, and the noise robustness in enhanced by the noise filtering during the decomposition and reconstruction process. Numerical validations are performed on plate-like structures for various damage and boundary scenarios. Validations show that the proposed method is accurate and effective in the damage detection for the two-dimensional structures.

• Current Optics and Photonics
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• v.2 no.4
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• pp.332-339
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• 2018

A new multi-frequency fringe projection method is proposed to reduce the nonlinear phase error in 3-D shape measurements using an adaptive compensation method. The phase error of the traditional fringe projection technique originates from various sources such as lens distortion, the nonlinear imaging system and a nonsinusoidal fringe pattern that can be very difficult to model. Inherent possibility of phase error appearing hinders one from accurate 3-D reconstruction. In this work, an adaptive compensation algorithm is introduced to reduce adaptively the phase error resulting from the fringe projection profilometry. Three different frequencies are used for generating the gratings of projector and conveyed to the four-step phase-shifting procedure to measure the objects of very discontinuous surfaces. The 3-D shape results show that this proposed technique succeeds in reconstructing the 3-D shape of any type of objects.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04b
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• pp.715-717
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• 2004

This paper proposes a new reconstruction method of high-resolution facial image from a low-resolution facial image based on a recursive error back-projection of top-down machine learning. A face is represented by a linear combination of prototypes of shape and texture. With the shape and texture information about the pixels in a given low-resolution facial image, we can estimate optimal coefficients for a linear combination of prototypes of shape and those of texture by solving least square minimization. Then high-resolution facial image can be obtained by using the optimal coefficients for linear combination of the high-resolution prototypes, In addition to, a recursive error back-projection is applied to improve the accuracy of synthesized high-resolution facial image. The encouraging results of the proposed method show that our method can be used to improve the performance of the face recognition by applying our method to reconstruct high-resolution facial images from low-resolution one captured at a distance.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.6_1
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• pp.507-516
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• 2007

Segmentation and organization of the LiDAR (Light Detection and Ranging) data of the Earth's surface are difficult tasks because the captured LiDAR data are composed of irregularly distributed point clouds with lack of semantic information. The reason for this difficulty in processing LiDAR data is that the data provide huge amount of the spatial coordinates without topological and/or relational information among the points. This study introduces LiDAR data segmentation technique by utilizing histograms of the LiDAR height image data and analyzing roof shape for 3D reconstruction and visualization of the buildings. One of the advantages in utilizing LiDAR height image data is no registration required because the LiDAR data are geo-referenced and ortho-projected data. In consequence, measurements on the image provide absolute reference coordinates. The LiDAR image allows measurement of the initial building boundaries to estimate locations of the side walls and to form the planar surfaces which represent approximate building footprints. LiDAR points close to each side wall were grouped together then the least-square planar surface fitting with the segmented point clouds was performed to determine precise location of each wall of an building. Finally, roof shape analysis was performed by accumulated slopes along the profiles of the roof top. However, simulated LiDAR data were used for analyzing roof shape because buildings with various shapes of the roof do not exist in the test area. The proposed approach has been tested on the heavily built-up urban residential area. 3D digital vector map produced by digitizing complied aerial photographs was used to evaluate accuracy of the results. Experimental results show efficiency of the proposed methodology for 3D building reconstruction and large scale digital mapping especially for the urban area.

• Archives of Plastic Surgery
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• v.32 no.2
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• pp.231-236
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• 2005

Nowadays breast reconstruction with autologous tissues after radical mastectomy is commonly performed, and a natural inframammary fold in the reconstructed breast is considered to be an essential aspect of symmetrical breast shape and location. Total of 104 patients underwent breast reconstruction with free TRAM flap and formation of inframammary fold with free TRAM breast reconstruction was done in 79 patients. No suture fixation for inframammary fold were done in 19 patients. 27 patients(24.0%) were made of inframammary fold with absorbable suture, 52 patients (50.0%) underwent inframammary fold creation with nonabsorbable suture. There were 4 cases(16.0%) of displacement of reconstructed breast and 2 cases(8.0%) of partial disruption of inframammary fold in the group of no suture. There were 2 cases(7.4%) of displacement of reconstructed breast and 3 cases(11.1%) of partial disruption of inframmamary fold in the fixed group with absorbable suture. There was only 1 case(1.9%) of partial disruption of inframammary fold fixed with nonabsorbable suture group. Therefore, we could speculate that the reinforcement of ligamentous structure for making the definite inframammary fold is necessary, and the area of the inframammary fold should not be undermined in immediate breast reconstruction as much as possible in order to preserve the zone of adherence. If the fold is disrupted during the mastectomy, it should be re-created with the non-absorbable sutures. Nonabsorbable suture fixation seemed to be more stable than absorbable suture. Preoperative marking and design are very important to make the symmetrical shape and location of inframammary fold in both of immediate and delayed reconstruction of breasts.

• Archives of Plastic Surgery
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• v.44 no.5
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• pp.413-419
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• 2017

Background In breast reconstruction using implants after unilateral mastectomy, it is challenging to create a natural, ptotic contour, and asymmetry is a potential drawback. To achieve breast symmetry and an ideal shape for both breasts, we performed contralateral augmentation in patients undergoing breast reconstruction with implants. Methods Patients underwent unilateral mastectomy and 2-stage reconstruction. During the second stage of the procedure, contralateral augmentation mammoplasty was performed. Preoperatively, we obtained the patients' demographic information, and we then assessed breast volume, the volume and dimensions of the inserted implants, and complications. Breast symmetry was observed by the surgeon and was assessed by measuring the disparity between the final volume of each breast. Results Contralateral augmentation was performed in 52 cases. When compared to patients who did not undergo a contralateral balancing procedure, patients who received contralateral augmentation were younger, thinner, and had smaller breasts. During implant selection for contralateral augmentation, we chose implants that were approximately 1 cm shorter in width, 1 level lower in height, and 1 or 2 levels lower in projection than the implants used for reconstruction. The postoperative breast contours were symmetric and the final volume discrepancy between each breast, which was measured by 3-dimensional scanning, was acceptable. Conclusions We demonstrate that contralateral augmentation can be recommended for patients who perceive their breasts to be small and not beautiful in order to achieve an ideal and beautiful shape for both breasts. Furthermore, this study offers guidelines for selecting the implant that will lead to the optimal aesthetic outcome.

• Archives of Craniofacial Surgery
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• v.12 no.2
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• pp.111-115
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• 2011

Purpose: Reconstruction of a full thickness defect of the nose is a difficult task for plastic surgeons because the anatomical characteristic, shape, and function of the nose all need to be taken into consideration. Most often, a local flap or a composite graft is used, but for a large defect, reconstruction using free flaps is the most ideal method. In free flap reconstruction, the chondrocutaneous preauricular area can be a suitable donor site. We performed a chondrocutaneous preauricular free flap with an interpositional vascular graft for reconstruction of a nasal ala. Methods: A 46 year-old male presented to the hospital with a right alar deformity induced by a dog bite. During the surgery, the existing scar tissue was removed and thereby a newly formed full thickness defect was reconstructed using the chondrocutaneous preauricular free flap with an interpositional vascular graft harvested from the descending branch of the lateral femoral circumflex vessel between the facial and superficial temporal vessels of the free flap. Results: The flap survived without flap loss and showed symmetry in its overall shape, contour, texture, and color. The patient was satisfied with the results and the surgery yielded no additional scars at the nasolabial fold area. Conclusion: The chondrocutaneous preauricular free flap is a valuable method in reconstruction of full thickness defects of the nose, and using the descending branch of the lateral femoral circumflex vessel as the interpositional vascular graft at the anastomotic site produces reliable results.