• 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.

• 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.

• 로봇학회논문지
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• 제15권4호
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• pp.323-329
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• 2020

This paper presents a control algorithm for a wearable walking aid robot for subjects with paraplegia after stroke. After a stroke, a slow, asymmetrical and unstable gait pattern is observed in a number of patients. In many cases, one leg can move in a relatively normal pattern, while the other leg is dysfunctional due to paralysis. We have adopted the so-called assist-as-needed control that encourages the patient to walk as much as possible while the robot assists as necessary to create the gait motion of the paralyzed leg. A virtual wall was implemented for the assist-as-needed control. A position based admittance controller was applied in the swing phase to follow human intentions for both the normal and paralyzed legs. A position controller was applied in the stance phase for both legs. A power controller was applied to obtain stable performance in that the output power of the system was delimited during the sample interval. In order to verify the proposed control algorithm, we performed a simulation with 1-DOF leg models. The preliminary results have shown that the control algorithm can follow human intentions during the swing phase by providing as much assistance as needed. In addition, the virtual wall effectively guided the paralyzed leg with stable force display.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제40권
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• pp.2.1-2.7
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• 2018

With the development of computer-aided design/computer-aided manufacturing (CAD/CAM) technology, it has been possible to reconstruct the cranio-maxillofacial defect with more accurate preoperative planning, precise patient-specific implants (PSIs), and shorter operation times. The manufacturing processes include subtractive manufacturing and additive manufacturing and should be selected in consideration of the material type, available technology, post-processing, accuracy, lead time, properties, and surface quality. Materials such as titanium, polyethylene, polyetheretherketone (PEEK), hydroxyapatite (HA), poly-DL-lactic acid (PDLLA), polylactide-co-glycolide acid (PLGA), and calcium phosphate are used. Design methods for the reconstruction of cranio-maxillofacial defects include the use of a pre-operative model printed with pre-operative data, printing a cutting guide or template after virtual surgery, a model after virtual surgery printed with reconstructed data using a mirror image, and manufacturing PSIs by directly obtaining PSI data after reconstruction using a mirror image. By selecting the appropriate design method, manufacturing process, and implant material according to the case, it is possible to obtain a more accurate surgical procedure, reduced operation time, the prevention of various complications that can occur using the traditional method, and predictive results compared to the traditional method.

• 한국임상약학회지
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• 제31권4호
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• pp.285-292
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• 2021

Background: Recently, the Korean Association of Pharmacy Education has been focusing on competency-based education (CBE) and has established required areas of competencies to improve the graduation competency. However, competency-based assessment (CBA) tools for implementing CBE have not yet been developed for faculty members and students to successfully access the assessment tests. Moreover, the faculty members in charge in pharmacy schools have encountered various barriers in recruiting individuals with integrated clinical experience to act as virtual patients. Therefore, this study aimed to identify the advantages and limitations of applying CBA tool and faculty assessors in the development of CBE to ensure the reliability of this assessment. Methods: Utilizing CBA tool, the students' communication skills and styles were assessed. students and faculty assessors were surveyed to evaluate the advantages and limitations of the CBA tool. Results: 8 assessors and 96 students participated in this study. 100% (8/8) of the faculty assessors and 77.4% (65/84) of the students reported that CBA tool is valuable to assess and improve student's ability. 90.5% (76/84) of the students felt confident in applying knowledge to patient-centered care. CBA tool can be a valuable for the instructors in identifying the competency level of students but can also be associated with limitations in implementation to ensure the objectivity and reliability of the CBA. Conclusions: The CBA tool can be valuable in assessing the level of students' competency. Faculty assessors have the advantage of well-prepared themselves for patient roles, so that the time and cost required may be minimized.