• Journal of Radiation Protection and Research
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• 제42권1호
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• pp.9-15
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• 2017

Background: The purpose of this study is to assign an appropriate density to virtual phantom for 2D diode array detector with different dose calculation algorithms to guarantee the accuracy of patient-specific QA. Materials and Methods: Ten VMAT plans with 6 MV photon beam and ten VMAT plans with 15 MV photon beam were selected retrospectively. The computed tomography (CT) images of MapCHECK2 with MapPHAN were acquired to design the virtual phantom images. For all plans, dose distributions were calculated for the virtual phantoms with four different materials by AAA and AXB algorithms. The four materials were polystyrene, 455 HU, Jursinic phantom, and PVC. Passing rates for several gamma criteria were calculated by comparing the measured dose distribution with calculated dose distributions of four materials. Results and Discussion: For validation of AXB modeling in clinic, the mean percentages of agreement in the cases of dose difference criteria of 1.0% and 2.0% for 6 MV were $97.2%{\pm}2.3%$, and $99.4%{\pm}1.1%$, respectively while those for 15 MV were $98.5%{\pm}0.85%$ and $99.8%{\pm}0.2%$, respectively. In the case of 2%/2 mm, all mean passing rates were more than 96.0% and 97.2% for 6 MV and 15 MV, respectively, regardless of the virtual phantoms of different materials and dose calculation algorithms. The passing rates in all criteria slightly increased for AXB as well as AAA when using 455 HU rather than polystyrene. Conclusion: The virtual phantom which had a 455 HU values showed high passing rates for all gamma criteria. To guarantee the accuracy of patent-specific VMAT QA, each institution should fine-tune the mass density or HU values of this device.

• Journal of Korean Dental Science
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• 제16권2호
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• pp.105-114
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• 2023

The axial contour and proximal contact of the prosthesis affect periodontal health, food impaction, and patient satisfaction. This narrative review provides a summary of articles regarding the axial contour and proximal contact of a fixed dental prosthesis on periodontal health and physiologic function. By acquiring a comprehensive understanding of the axial contour and proximal contact of teeth and prostheses, as well as their functional significance, the virtual design of fixed dental prosthesis can be optimized to maintain periodontal health and promote physiologic function effectively.

• Journal of Radiation Protection and Research
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• 제38권4호
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• pp.194-201
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• 2013

To investigate monitoring unit (MU) efficiency and plan quality of volumetric modulated arc therapy (VMAT) using flattening-filter free (FFF) photon beam in association with target size and location. A virtual patient was generated in Eclipse$^{TM}$ (ver. A10, Varian Medical Systems, Palo Alto, USA) treatment planning system. The length of major and minor axis in axial view was 50 cm and 30 cm, respectively. Cylindrical-shaped targets were generated inside that patient at the center (symmetric target) and in the periphery (asymmetric target, 7.5 cm away from the center of the patient to the right direction) of the virtual patient. The longitudinal length was 10 cm and the diameters were 2, 5, 10 and 15 cm. Total 8 targets were generated. RapidArc$^{TM}$ plans using TrueBeam STx$^{TM}$ were generated for each target. Two full arcs were used and the axis of rotation of the gantry was set to be at the center of the virtual patient. Total MU, homogeneity index (HI), target mean dose, the value of gradient measure and body mean dose were calculated. In the case of symmetric targets, averaged total MU of FFF plan was 23% and 19% higher than that of flattening filter (FF) plan when using 6 MV and 10 MV photons, respectively. The difference of HI, target mean dose, gradient measure and body mean dose between FF and FFF was less than 0.04, 2.6%, 0.1 cm and 2.2%, respectively. For the asymmetric targets, total MU of FFF plan was 21% and 32% was higher than that of FF when using 6 MV and 10 MV photons, respectively. The homogeneity of the target was always worse when using FFF than using FF. The maximum difference of HI was 0.22. The target mean dose of FFF was 3.2% and 4.1% higher than that of FF for the 6 MV and 10 MV, respectively. The difference of gradient measure was less than 0.1 cm. The body mean dose was higher when using FFF than FF about 4.2% and 2.8% for the 6 MV and 10 MV, respectively. No significant differences between VMAT plans of FFF beam and FF beam were observed in terms of quality of treatment plan. The HI was higher when using FFF 10 MV photons for the asymmetric targets. The MU was increased noticeably when using FFF photon beams.

• 한국정보통신학회논문지
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• 제21권7호
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• pp.1379-1385
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• 2017

가상훈련은 특정한 훈련을 목적으로 훈련에 필요한 환경이나 상황을 가상으로 구현하여 실제 상황처럼 진행하는 교육 훈련으로써 최근에는 가상현실 기술의 급격한 발전으로 인해 현실세계에서 직접 경험하지 못하는 상황을 실감적으로 체험하는 것에 대한 요구가 더욱 증대하고 있다. 특히, 안전 불감증으로 인해 수많은 재난 사고로 인명 피해가 끊이지 않는 우리나라에서는 안전교육이 매우 필요하므로 가상현실을 이용한 재난대응 훈련 시뮬레이션이 어느 때보다 시급하다. 본 논문에서는 가상현실 기술을 이용하여 심장충격기인 자동제세동기(AED) 훈련 시스템을 제안하고 구현한다. 자동제세동기는 급성심장정지 환자를 구출하기 위해 가장 필요한 의료 기기임에도 불구하고 사용법을 숙지하고 있는 사람이 많지 않아 국내에서 자동제세동기를 사용하여 환자의 생명을 구한 사례는 매우 미미하다. 제안하는 AED 가상훈련 시스템은 실제와 같은 상황에서 몰입감이 있고 체험적인 훈련이 가능하며 저렴한 비용으로 훈련이 가능하여 매우 유용하다.

• The Korean Journal of Pain
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• 제35권4호
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• pp.403-412
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• 2022

Background: Most pain management techniques for challenging procedures are still performed under the guidance of the C-arm fluoroscope although it is sometimes difficult for even experienced clinicians to understand the modified three-dimensional anatomy as a two-dimensional X-ray image. To overcome these difficulties, the development of a virtual simulator may be helpful. Therefore, in this study, the authors developed a virtual simulator and presented its clinical application cases. Methods: We developed a computer program to simulate the actual environment of the procedure. Computed tomography (CT) Digital Imaging and Communications in Medicine (DICOM) data were used for the simulations. Virtual needle placement was simulated at the most appropriate position for a successful block. Using a virtual C-arm, the authors searched for the position of the C-arm at which the needle was visualized as a point. The positional relationships between the anatomy of the patient and the needle were identified. Results: For the simulations, the CT DICOM data of patients who visited the outpatient clinic was used. When the patients revisited the clinic, images similar to the simulated images were obtained by manipulating the C-arm. Transforaminal epidural injection, which was difficult to perform due to severe spinal deformity, and the challenging procedures of the superior hypogastric plexus block and Gasserian ganglion block, were successfully performed with the help of the simulation. Conclusions: We created a pre-procedural virtual simulation and demonstrated its successful application in patients who are expected to undergo challenging procedures.

• 한국간호교육학회지
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• 제30권3호
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• pp.290-300
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• 2024

Purpose: Nursing clinical practice education is transforming with the advent of mobile education and the unique experiences it offers in caring for virtual patients. For this innovative approach, this study aims to evaluate the efficacy of mobile-based virtual women's breast cancer nursing simulation training content on nursing students' confidence, satisfaction, and learning flow. It also examines the nursing students' virtual patient care experiences. Methods: A mixed methods approach using a convergent design was employed to examine students' cancer care confidence and satisfaction, learning flow, and learning experiences. Quantitative data through online questionnaires and qualitative data through focus group interviews were collected, merged, and analyzed. Results: This study developed a virtual nursing training module aimed at caring for women with breast cancer, a novel approach to facilitate mobile-based simulation training for nursing students. Data were analyzed using descriptive analysis, a chi-squared test, Fisher's exact test, t-test for participant homogeneity (experimental: 20, control: 20), independent t-test, and paired t-test. Satisfaction (t=3.53, p=.001) and confidence (t=4.07, p=.001), as well as flow (t=3.78, p=.001), significantly improved in the experimental group compared to the control group. Two core themes and five sub-themes were derived from the experimental group's experiences acquired by caring for women with breast cancer virtually, including that the students "Virtually cared for breast cancer patients, learning as if real." Conclusion: The mobile-based virtual nursing simulation training content allowed nursing students to upgrade their comprehensive nursing care skills by experiencing a fun and practical environment made possible by a new learning method.

• 대한치과보철학회지
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• 제57권4호
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• pp.425-431
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• 2019

본 임상증례는 전치부 영역에서 안면영상, 콘빔 컴퓨터 단층촬영 그리고 구내 스캔영상을 이용하여 보철물을 시각화하는 과정을 보여준다. 이러한 접근 방식은 임상과 기공 그리고 환자 측과의 소통을 향상시킨다. 환자가 상악 중절치의 외상 후 보철치료를 위해 내원하였고, 전신 건강 상태는 양호하였다. 안면연상, 콘빔 컴퓨터 단층촬영 그리고 구내 스캔영상을 이용하여 가상 환자 모형을 제작하였다. 최종 보철물의 제작 전 보철물 디자인 영상이 환자에게 제시되었고, 환자의 의견을 반영하여 형태를 수정하였다. 이러한 디지털 작업 과정은 최적의 심미 보철물의 제작을 용이하게 하고, 보철물의 예측성을 향상시킨다.

• Archives of Plastic Surgery
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• 제47권2호
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• pp.178-181
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• 2020

In this report, we present a case in which good results were achieved by treatment using a free jejunal patch graft with virtual endoscopy (VE) assistance in a patient whose swallowing had failed to improve for 40 years after he mistakenly swallowed sulfuric acid, despite pectoralis major myocutaneous flap grafting and frequent balloon dilatation surgery. During the last 20 years, virtual computed tomography imaging has improved remarkably and continues to be used to address new challenges. For reconstructive surgeons, the greatest advantage of VE is that it is a noninvasive modality capable of visualizing areas inaccessible to a flexible endoscope. Using VE findings, we were able to visualize the 3-dimensional shape beyond the stenosis. VE can also help predict the area of the defect after contracture release.

• 재활치료과학
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• 제7권2호
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• pp.17-27
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• 2018

목적 : 본 연구는 만성 뇌졸중 환자를 대상으로 완전 몰입형 가상현실 기기를 이용한 작업치료 중재가 환자의 상지기능 향상에 미치는 효과를 알아보고자 하였다. 연구방법 : 본 연구의 연구 대상은 좌측 편마비를 가지고 있는 만성 뇌졸중 환자 1명이며, 개별사례 실험연구 중 ABA 설계를 사용하였다. 기초선 기간 4회, 중재 기간 12회, 기초선 회귀기간 4회로 총 20회의 실험을 휴지기간을 포함하여 총 10주간 진행하였다. 독립변수인 완전 몰입형 가상현실 기기를 이용한 작업치료 중재는 매 회기 30분씩 시행되었으며 종속변수 중 Fugl-Meyer Assessment(FMA) 평가는 각 기간 마다 1회씩 측정하였다. Box and Block Test(BBT) 평가와 Wolf Motor Function Test(WMFT) 평가는 매 회기 마다 시행하여 그 측정 결과를 꺾은선 그래프를 통해 제시하였다. 결과 : 완전 몰입형 가상현실 기기를 이용한 작업치료 중재 후 대상자의 환측 상지기능이 향상되었다. 기초선 회귀 기간에는 중재를 제거한 뒤 치료유지 효과를 확인하였지만 큰 변화는 나타나지 않았다. 결론 : 본 연구의 결과, 완전 몰입형 가상현실 기기를 이용한 작업치료 중재가 만성 뇌졸중 환자의 상지기능에 효과적인 중재라는 것을 알 수 있었다. 다만 치료유지 효과는 크지 않았기 때문에 보다 사용이 간편한 가정용 중재 프로그램 등의 개발이 필요하다.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2002년도 추계학술대회 논문집
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• pp.233-244
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• 2002

뇌기능 장애 환자에서 자세균형 제어능력의 저하는 보행 및 일상생활동작 수행 등에 어려움을 초래하며 이에 대한 정확한 평가 및 치료를 위하여 일상의 환경변화와 유사한 상황을 제공하고 이예 따른 자세제어력을 파악하는 것이 중요하다. 본 연구는 뇌기능 장애환자에서 움직이는 환경에 따른 자세균형제어기능을 정확히 평가하는 환경의 움직임이 자세균형제어에 미치는 영향을 분석하였다. 15명의 뇌기능 장애 환자들과 정상인 15명을 대상으로 실생활과 유사한 환경의 조성을 위하여 HMD를 이용한 가상영상 환경변화(Moving Surround)를 네가지 움직임 종류에 따라 제공하였다. 자세동요의 정도는 힘판을 이용하여 신체압력중심의 변화를 전체이동거리, 동요주파수, 최대 빈도 COP 위치 등으로 측정하였으며 환경의 차이에 따른 변화를 비교 분석하였다. 연구결과 검사 재검사 신뢰도 평가에서 일관된 분석결과를 나타냈고 뇌기능장애 환자와 정상인간의 분석에서는 두 그룹간의 차이를 확인할 수 있었다. 특히 전후로 빠르게 변하는 가상영상 환경에서 가장 큰 자세동요를 나타내었고 통계적으로 유의한 차이가 있었다. 본 연구를 통해 뇌기능 장애 환자에서 가상영성 환경변화가 자세균형제어에 미치는 영향을 확인할 수 있었으며 이러한 환자들을 위한 치료환경 조성 등에도 유용한 자료로 쓰일 수 있을 것으로 사료된다.