• Maxillofacial Plastic and Reconstructive Surgery
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• 제37권
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• pp.20.1-20.7
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• 2015

Background: The objectives of the present study were to investigate the reliability and outcomes of computer-assisted techniques in mandibular reconstruction with a fibula flap and verify whether the surgical navigation system was feasible in mandible reconstructive surgery. Methods: Eight cases were enrolled in the computer assisted surgery (CAS) group and 14 cases in the traditional group. The shaping and fixation of the fibula grafts were guided by computer assisted techniques, which could be monitored with the BrainLAB surgical navigation system. The variation of mandible configuration was evaluated by CT measurement in the Mimics software, including the variation of length, width, height and gonial angle of the mandible. The 3D facial soft tissue alteration was also analyzed in 3D chromatogram by Geomagic software. Results: All 22 fibula flaps survived. The mandibular configurations and facial contours had a better clinic result in the CAS group. The length, width, height and gonial angle of the reconstructive mandible were more similar to the original one. The Wilcoxon rank sum test analysis suggested significant differences in the measurements. The chromatographic analysis also visually showed superiority over the traditional group. Conclusions: The computer assisted surgical navigation method used in mandibular reconstruction is feasible and precise for clinical application. The contour of the reconstructed mandible and facial symmetry are improved with computer techniques.

• 대한정형외과학회지
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• 제53권6호
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• pp.478-489
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• 2018

슬관절의 골관절염 환자에서 슬관절 전치환술은 통증 경감 및 기능 회복에 도움이 되는 치료법으로 많이 시행되고 있다. 최근 수술 술기 및 과학 기술의 발달로 인하여 내비게이션 장치를 이용하여 슬관절 전치환술 후 하지 정렬과 치환물의 위치 및 정렬을 호전시키려는 노력이 지속적으로 이루어지고 있다. 이러한 내비게이션 장치를 이용할 경우 수술 중에 신전, 굴곡 시 내외측 간격, 하지 및 치환물의 정렬에 대하여 실시간 추적이 가능하다는 장점이 있다. 하지만 고식적인 방법에 비해 추적기 사용에 따른 추가적 절개로 인한 감염 및 골절 등의 합병증 발생 가능성이 있고 수술 시간이 길어지는 단점 및 비용 부담 등이 지적되어 왔다. 지금까지 많은 연구들이 진행되어 왔으나 임상적 효용성에 대해서는 아직까지 논란이 있다. 하지만 많은 연구들에서 관상면 상에서 역학적 축 내, 외반 $3^{\circ}$이내의 정렬 빈도를 높여주는 것으로 보고되고 있다. 이번 종설에서는 내비게이션 장치를 이용한 슬관절 전치환술의 수술 방법 및 수술 시 주의사항, 최근 연구들의 임상적 결과 및 방사선적 결과, 내비게이션 장치의 유용성과 최근 동향에 대하여 기술하고자 한다.

• Journal of International Society for Simulation Surgery
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• 제2권2호
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• pp.83-86
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• 2015

Recently, computer-assisted surgery is popular for performing well-planned operations. Computer-aided navigation system is helpful in maxillofacial surgery with real time instrument positioning and clear anatomic identification. Generally, segmental mandibulectomy and reconstruction flap surgery have done by extra-oral approach such as, submandibular approach. This case report describes performing intra-oral segmental mandibulectomy and reconstruction with monocortical deep circumflex iliac artery (DCIA) flap and CT guided implant surgery by using computer-aided surgical guide and navigation for managing ameloblastoma in a 31 years old female patient.

• 대한골관절종양학회지
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• 제15권1호
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• pp.1-6
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• 2009

컴퓨터를 이용한 정형외과 수술(Computer-assisted orthopaedic surgery, CAOS) 분야는 인공관절 치환술, 십자 인대 재건술, 척추경 나사삽입술 등의 수술에서 그 효용성과 정확성에 대해 많은 평가가 있었다. 최근에는 골종양 의 절제와 종양 절제 후 발생한 골결손 재건에 적용한 증례가 보고되고 있다. 종양과 정상조직 간의 3차원 관계를 보여 줌으로써, 종양의 안전한 절제 뿐 아니라 기능의 보존을 최대화하는데 도움을 줄 수 있다. 그러나, navigation을 골종양 수술에 이용하기 위해서는 사용방법에 대한 완벽한 이해와 정확성 뒤에 숨어있는 오차에 대해 숙지하고 있어야 할 것이다. 저자의 임상 경험을 토대로 종양 수술에서 navigation을 이용할 때 수술 방법과 일반 정형외과 수술에서의 navigation 사용과 다른 점을 기술하고자 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권8호
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• pp.3270-3294
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• 2020

Some things come easily to humans, one of them is the ability to navigate around. This capability of navigation suffers significantly in case of partial or complete blindness, restricting life activity. Advances in the technological landscape have given way to new solutions aiding navigation for the visually impaired. In this paper, we analyze the existing works and identify the challenges of path selection, context awareness, obstacle detection/identification and integration of visual and nonvisual information associated with real-time assisted mobility. In the process, we explore machine learning approaches for robotic path planning, multi constrained optimal path computation and sensor based wearable assistive devices for the visually impaired. It is observed that the solution to problem is complex and computationally intensive and significant effort is required towards the development of richer and comfortable paths for safe and smooth navigation of visually impaired people. We cannot overlook to explore more effective strategies of acquiring surrounding information towards autonomous mobility.

• 대한의용생체공학회:의공학회지
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• 제29권6호
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• pp.451-456
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• 2008

Total knee arthroplasty(TKA) using computer-assisted navigation has been increased in order to improve the accuracy of femoral and tibial components implantation. Recently, a few clinical studies have reported on the femoral stress fracture after TKA using computer-assisted navigation. The purpose of this study is to investigate the stress concentration around the femoral pin-hole for different pin-hole diameter, the modes of pin penetration by finite element analysis to understand the effects of pin-hole parameters on femoral stress fracture risk. A three-dimensional finite element model of a male femur was reconstructed from 1 mm thick computed tomography(CT) images. The bone was rigidly fixed to a 25 mm above the distal end and 1500 N of axial compressive force and 12 Nm of axial torsion were applied at the femoral head. For all cases, transcortical pin penetration mode showed the highest stress fracture risk and unicortical pin penetration mode showed the lowest stress concentration. Pin-hole diameter increased the stress concentration, but pin number did not increase the stress dramatically. The results of this study provided a biomechanical guideline for pin-hole fracture risk of the computer navigated TKA.

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

• Knee surgery & related research
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• 제30권4호
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• pp.326-333
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• 2018

Purpose: To evaluate the reliability and validity of the femorotibial mechanical axis angle from radiographs in the weight bearing (WB) and supine positions compared with navigation-measured values. Materials and Methods: Sixty-eight cases of navigation-assisted total knee arthroplasty (TKA) were included. The pre- and postoperative whole leg radiographs (WLRs) in WB and supine positions were compared with the initial and final navigation values. Results: The mean mechanical axis angle from the preoperative WBWLR and navigation were not statistically different (p=0.079) and were correlated strongly with each other (intraclass correlation [ICC], 0.818). However, on postoperative measurements, although the WBWLR and navigation values were not different (p=0.098), they were not correlated with each other (ICC, 0.093). The standard error of measurement was $1.8^{\circ}{\pm}3.6^{\circ}$ for the preoperative WBWLR and $2.5^{\circ}{\pm}4.8^{\circ}$ for the postoperative WBWLR. The validity that was determined by the Bland-Altman plot was not acceptable for both pre- and postoperative measurements. Conclusions: The preoperative WBWLR could provide accurate but not precise measurement value of the femorotibial mechanical axis angle for navigation-assisted TKA, and postoperative measurements in navigation were not comparable with radiographic measurements. The lack of agreement was found between the radiographic and navigation measurements of the coronal alignment regardless of pre- or postoperative evaluation although the accuracy was found acceptable. Level of Evidence : Level 4.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2015년도 추계학술대회
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• pp.233-236
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• 2015

전 세계 해기교육기관에서 해사영어(Maritime English, ME)를 가르치고 있는 교원들이 모여 매년 개최하는 IMEC (International Maritime English Conference)을 소개하고, 2015년에 개최된 제27차 컨퍼런스의 프로그램을 우리 회원들에게 안내하고자 하며, IMEC 27에서 소개된 ChatBot를 가지고 참석한 회원들과 함께 진행하는 워크숍을 개최하고자 한다.

• Journal of Korean Neurosurgical Society
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• 제50권6호
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• pp.523-527
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• 2011

A 67-year-old woman presented for evaluation of severe coccygeal pain. The computed tomography scans and magnetic resonance imaging showed an asymmetric midline sacral tumor invading the right lower portion of S2. To preserve both S2 nerve roots and to obtain negative surgical margins, a modified mid-sacrectomy with an aid of a computed navigation system was performed. The sacral tumor was excised en bloc with negative tumor margins. Both S2 nerve roots were preserved and additional reconstruction was not necessary because of minimal resection of the sacroiliac joint. We report a case of a sacral chordoma which was excised en bloc with adequate surgical margins by a computer-assisted modified mid-sacrectomy. The computed navigation system may be a useful tool for tumor targeting and safe osteotomies in sacral tumor surgery via the posterior only approach.