• Journal of the Korean Society for Precision Engineering
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• v.21 no.6
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• pp.188-196
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• 2004

The objective of this paper is to propose a new technology of the orthopaedic surgery using the combination of reverse engineering (RE) based on CT data and rapid prototyping (RP). The proposed technology utilizes symmetrical characteristics of the human body and capability of the combination of RE and RP, which rapidly manufactures three-dimensional parts from CT data. The original .stl data of injured extents are generated from the mirror transformation of .stl file fur uninjured extents. The physical shape before injuring is manufactured from RP using the original .stl data. Subsequently, pre-operative planning, such as a selection of proper implants, preforming of the implant, a decision of fixation locations and an insert position for the implant, an estimation of the invasive size, and pre-education of operators are performed using the physical shape. In order to examine the applicability and the efficiency of the proposed surgical technology, various case studies, such as a distal tibia commented fracture, a proximal tibia plateau fracture and an iliac wing fracture of pelvis, are carried out. From the results of case studies, it has been shown that the proposed technology is an effective surgical tool of the orthopaedic surgery reducing the operational time, the operational cost, the radiation exposure of the patient and operators, and morbidity. In addition, the proposed technology could improve the accuracy of operation and the speed of rehabilitation.

• Archives of Reconstructive Microsurgery
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• v.8 no.1
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• pp.35-43
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• 1999

There are lots of reconstructive ways like direct closure, skin graft, local flap, regional flap, distant flap, free flap and so on. Microsurgical reconstruction is regarded as the last step in various reconstructive methods. So the failure of this last step causes the troublesome situation for both of patients and surgeon. The purpose of this paper is to investigate the problems in failed free flap surgery and to introduce the strategy of appropriate management in wound of free flap failure. We performed 252 cases of free flap surgeries from May, 1988 to June, 1998. Among these cases, we failed 9 cases of free flaps. Patients' age ranged from 19 to 63. There were 7 males and 2 females. Site of failure were 3 head and neck areas, 2 hands, and 4 lower extremities. However there was no failure in breast, trunk, buttock, and genitalia. 7 patients who had region of head and neck, and lower extremity underwent the second free flap surgery successfully in postoperative 4 to 16 days following debridement of necrotic tissue. However 2 patients who had region in hand were managed with conventional treatment like skin graft and distant flap. Vein grafts were needed in 3 cases of 7 second free flaps, and 1 patients needed sequentially-linked free flaps with two flaps. The second free flaps were inevitable for head and neck area because the large complex wound may cause the lifethreatening condition without immediate coverage with well vascularized flap. Lower extremity also needed second free flap for limb salvage. Hand could be managed with conventional method, even though healing time was quite delayed. We thought second free flap surgery in free flap failure cases should be performed with more careful preoperative evaluation and refined surgery. Success of second free flap surgery could recover the very difficult situation due to previously failed operation.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.175-179
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• 2016

Recent advances in technology of medical image have made surgical simulation that is helpful to diagnosis, operation plan, or education. Improving and enhancing the medical imaging have led to the availability of high definition images and three-dimensional (3D) visualization, it allows a better understanding in the surgical and educational field. The Real human field of view is stereoscopic. Therefore, with just 2D images, stereoscopic reconstruction process through the surgeon's head, is necessary. To reduce these process, 3D images have been used. 3D images enhanced 3D visualization, it provides significantly shorter time for surgeon for judgment in complex situations. Based on 3D image data set, virtual medical simulations, such as virtual endoscopy, surgical planning, and real-time interaction, have become possible. This article describes principles and recent applications of newer imaging techniques and special attention is directed towards medical 3D reconstruction techniques. Recent advances in technology of CT, MR and other imaging modalities has resulted in exciting new solutions and possibilities of shoulder imaging. Especially, three-dimensional (3D) images derived from medical devices provides advanced information. This presentation describes the principles and potential applications of 3D imaging techniques, simulation and printing in shoulder and elbow practice.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.4
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• pp.423-439
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• 2012

This case report described a technique utilizing a computer-aided design (CAD)/computer-aided machining (CAM) - guided surgical implant placement and prefabricated temporary fixed prosthesis for an immediately loaded restoration. The advantages of CAD/CAM guided implant procedures are flapless, minimally invasive surgery and shorter surgery time. With this technique, less postoperative morbidity and delivery of prosthesis for immediate function would be possible. A patient with an edentulous maxilla received 8 implants in maxilla using CAD/CAM surgical templates. Prefabricated provisional maxillary implant supported fixed prosthesis were connected immediately after implant installation. Provisional prosthesis was evaluated for aesthetics, function during 6 months. Definitive implant supported fixed porcelain fused metal bridges were fabricated.

• Proceedings of the KSMRM Conference
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• 1997.10a
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• pp.36-36
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• 1997

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.205-206
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• 2007

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.45-52
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• 2015

Purpose : The dose distribution of organ at risk (OAR) and normal tissue is affected by treatment technique in postoperative radiation therapy for prostate cancer. The aim of this study was to compare dose distribution characteristic and to evaluate treatment efficiency by devising VMAT plans according to applying differed number of arc and IMRT plan for postoperative patient of prostate cancer radiation therapy using a rectal balloon. Materials and Methods : Ten patients who received postoperative prostate radiation therapy in our hospital were compared. CT images of patients who inserted rectal balloon were acquired with 3 mm thickness and 10 MV energy of HD120MLC equipped Truebeam STx (Varian, Palo Alto, USA) was applied by using Eclipse (Version 11.0, Varian, Palo Alto, USA). 1 Arc, 2 Arc VMAT plans and 7-field IMRT plan were devised for each patient and same values were applied for dose volume constraint and plan normalization. To evaluate these plans, PTV coverage, conformity index (CI) and homogeneity index (HI) were compared and $R_{50%}$ was calculated to assess low dose spillage as per treatment plan. $D_{25%}$ of rectum and bladder Dmean were compared on OAR. And to evaluate the treatment efficiency, total monitor units(MU) and delivery time were considered. Each assessed result was analyzed by average value of 10 patients. Additionally, portal dosimetry was carried out for accuracy verification of beam delivery. Results : There was no significant difference on PTV coverage and HI among 3 plans. Especially CI and $R_{50%}$ on 7F-IMRT were the highest as 1.230, 3.991 respectively(p=0.00). Rectum $D_{25%}$ was similar between 1A-VMAT and 2A-VMAT. But approximately 7% higher value was observed on 7F-IMRT compare to the others(p=0.02) and bladder Dmean were similar among the all plan(P>0.05). Total MU were 494.7, 479.7, 757.9 respectively(P=0.00) for 1A-VMAT, 2A-VMAT, 7F-IMRT and at the most on 7F-IMRT. The delivery time were 65.2sec, 133.1sec, 145.5sec respectively(p=0.00). The obvious shortest time was observed on 1A-VMAT. All plans indicated over 99.5%(p=0.00) of gamma pass rate (2 mm, 2%) in portal dosimetry quality assurance. Conclusion : As a result of study, postoperative prostate cancer radiation therapy for patient using a rectal balloon, there was no significant difference of PTV coverage but 1A-VMAT and 2A-VMAT were more efficient for dose reduction of normal tissue and OARs. Between VMAT plans. $R_{50%}$ and MU were little lower in 2A-VMAT but 1A-VMAT has the shortest delivery time. So it is regarded to be an effective plan and it can reduce intra-fractional motion of patient also.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.1
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• pp.1-8
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• 2017

Purpose: The purpose of this study is to compare the accuracy of the CT guided implant template that was produced by using an intraoral scanner according to the edentulous distance. Materials and methods: Five maxillary casts were fabricated using radiopaque acrylic resin with the second premolars, first molars, and second molars missing. Then a virtual cast was acquired by scanning each resin cast. Implant treatment was planned on the missing sites by superimposing the presurgical CT DICOM file and the virtual cast. Then the implants were placed using a surgical template followed by postsurgical CT scan. The distance and angle of the platform and apex between the presurgical implant and postsurgical implant were measured using the X, Y, and Z axis of the superimposed presurgical CT and postsurgical CT via software followed by statistical analysis using Kruskall-Wallis test and Mann-Whitney test. Results: The implant placement angle error increased towards the second molars but there was no statistically significant difference. The implant placement distance error at the platform and apex also increased towards the second molars and there was a statistically significant error at the second molars. Conclusion: Although the placement angle had no statistically significant difference between the presurgical implant and postsurgical implant, the placement distance at the platform and apex showed a larger error and a statistically significant difference at the second molar implant.

• Journal of Korean Foot and Ankle Society
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• v.17 no.4
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• pp.243-250
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• 2013

Diabetic Charcot arthropathy is a severe joint disease in the foot and ankle that can result in fracture, permanent deformity, limb loss. Although recent research has improved our level of knowledge regarding its etiology and treatment, it still remains a poorly understood disease. It is a serious and potentially limb-threatening lower-extremity late complication of diabetes mellitus and its diagnosis is commonly missed upon initial presentation. Clinicians treating diabetic patients should be vigilant in recognizing early signs of acute Charcot arthropathy, such as pain, warmth, edema, or pathologic fracture in a neuropathic foot. Early detection and prompt treatment can prevent joint and bone destruction. If left untreated, it can reduce overall quality of life and dramatically increase morbidity and mortality of patients. The goal of this manuscript is to evaluate the current concepts of Charcot arthropathy through review of various literature and help clinicians decide the treatment strategy.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.737-739
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• 2023

몰입형 가상현실 시스템은 더 나은 3차원 시각정보를 제공할 수 있어, 의료계에서 해부학에 대한 이해를 높이는 데 사용되고 있다. 우리는 몰입형 가상현실에서 다중 사용자가 함께 MRI 영상으로부터 생성된 볼륨 렌더링 된 객체를 관찰하고 수술을 계획할 수 있는 시스템을 개발하여 소개하고자 한다.