• 전기의세계
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• v.63 no.2
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• pp.15-20
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• 2014

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.01a
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• pp.383-386
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• 2022

본 논문에서는 COVID-19와 같은 위급한 상황에서 바이러스 검사를 빠르게 진행하기 위한 K-d 트리 기반의 그래프 구축과 환자 이동 경로 시스템을 제안한다. 가상환경에서 활용되는 대표적인 길 찾기 알고리즘은 A^*나 NavMesh 자료구조는 정해진 정적 이동 경로만을 안내하려는 방법이기 때문에 가상환경에서 NPC를 제어할 때는 효율적이지만, 실제 환경에 적용하여 문제를 풀기에는 충분하지 않다. 특히, 빠른 바이러스 검사를 받기 위해서는 짧은 거리만을 이용하는 게 아닌, 실제 도로 교통상황, 병원의 크기, 환자 이동 수, 환자 처리 시간 등 고려해야 할 상황들이 많다. 본 논문에서는 위에서 언급한 다양한 속성들과 이를 이용한 최적화 함수를 모델링하여, 실제 도시 맵에서 바이러스 검사를 빠르고 효율적으로 제어할 수 있는 프레임워크를 제안한다.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.46-63
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• 2022

With the rapid development of digital technology and the growing trend to integrate it into the medical field, recent studies suggest language rehabilitation for people with aphasia using virtual reality (VR), augmented reality (AR) and mobile applications. This study conducted a scoping review to summarize the features of digital technology-based language rehabilitation for aphasia in the last four years (2018-2021) and draw implications for future research. A total of 20 papers met the selection criteria among the documents retrieved from the Web of Science, CINAHL, and RISS. This review demonstrates that digital technology could offer unique treatment content by gamification, individualization, and creating a realistic communication environment, and by utilizing them in various ways. Therefore, we expect digital technology-based language rehabilitation for aphasia could supplement the limitations of conventional language rehabilitation and provide a novel perspective on development of treatment content.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.169-174
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• 2016

In this study, we evaluated the virtual reality model for dental implant surgery and discussed about the method to make the surgical environment for virtual reality with practical patient data. The anatomical model for patient face was fabricated by facial and oral scan data based on CT data. The simulation scenario was composed step by step fashion with Unity3D. From incision and sinus bone graft procedure which is needed to this patient model to implant installation and bone graft was included in this scenario. We used the HMD and leap motion for immersiveness and feeling of real operation. Twenty training doctor was attended this simulation study, and surveyed their satisfactory results by questionnaire. Implant surgery education program was showed the possibilities of educational tool for dental students and training doctors. Virtual reality for surgical education with HMD and leap motion had advantages, in terms of cheap prcie, easy access.

• Therapeutic Science for Rehabilitation
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• v.8 no.4
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• pp.41-51
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• 2019

Objective : The purpose of this study was to investigate the effects of virtual reality-based activities of daily living (ADL) training on ADL and rehabilitative motivation in patients with traumatic brain injury. Methods : This study was performed using a pre-post design with seven traumatically brain injured patients. Subjects were subjected to virtual reality-based ADL training for 30 minutes a day, 2 to 3 times a week for 4 weeks. Evaluation was conducted before and after the intervention using the Korean Modified Barthel Index (K-MBI), Cognitive Functional Independence Measure (C-FIM), and Volitional Questionnaire (VQ). Changes before and after intervention were analyzed by Wilcoxon signed-rank test, and correlations were analyzed using Spearman's coefficient. Results : After intervention, patients with traumatic brain injury showed significant improvements in K-MBI (p<.05). There was no significant change in total C-FIM score and VQ score (p>.05). Total C-FIM score correlated significantly with VQ score (p<.05, r=.755). The social cognition domain of C-FIM had a significant correlation with VQ score (p<.05, r=826). Conclusions : Virtual reality-based ADL training can improve ADL performance, but further research is needed to determine whether improvements in social cognition and rehabilitative motivation are possible.

• Journal of Digital Convergence
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• v.17 no.9
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• pp.271-278
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• 2019

The aim of this study was to investigate the effects of virtual reality training on upper extremity function and activities of daily living in patients with sub-acute stroke. The present study enrolled 18 patients with sub-acute stroke. All subjects were assigned into either the experimental group (n=9) or control group (n=9). Both groups received conventional occupational therapy for 30 minutes/day, 5 times a week, for 4 weeks. Additionally, the experimental group performed virtual reality training in each session for 30 minutes/day, and the control group conducted conventional occupational therapy in each session for 30 minutes/day. The outcome measures were performed through the Fugl-Meyer Assessment (FMA) and the Korean-modified Barthel Index (K-MBI) before and after intervention. In results, the experimental group showed significant improvements in the scores of FMA and K-MBI after intervention (p<.05). The control group showed significant improvements in the shoulder/elbow/forearm, wrist, and hand sub-domains of the FMA and K-MBI (p<.05). After intervention, the experimental group showed significantly greater improvements in the total score and in the wrist and hand sub-domains of the FMA than control group (p<.05). These findings suggest that virtual reality training may have positive effects on the improvements of upper extremity function in patients with sub-acute stroke.

• 재활복지
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• v.21 no.4
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• pp.101-118
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• 2017

This study was conducted to investigate the effect of virtual reality game on old stroke patient's depression, relationship and life satisfaction. The subjects of this study were 40 stroke patients of over 65 years old and each 20 patients were randomly assigned in two groups. The study was conducted for 12 weeks. Nintendo Wii Sports Resort program was applied to the virtual reality game for the experimental group. In order to investigate psychological social factor (depression, relationship) and life satisfaction of the objects, BDI, RCS, LSI-Z were checked three times. The results are as followings. First, the psychological social change (depression, relationship) after the training program showed that depression is significantly decreased (p<.001) along with the intervention period in both 2 groups. Second, change of life satisfaction after the training program showed that significant statistical improvement were found both in control group(p<.05), and experimental group(p<.001). Third, depression, relationship showed the significant statistically correlation with life satisfaction(p<.05). We can conclude from the above that virtual reality games which were played by 2 persons had the significant effect on old stroke patient's psychological social factor(depression, relationship) and life satisfaction.

• Journal of the Korean Society of Radiology
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• v.83 no.6
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• pp.1286-1297
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• 2022

Purpose To assess the usefulness of various metal artifact reduction (MAR) methods in patients with hip prostheses. Materials and Methods This retrospective study included 47 consecutive patients who underwent hip arthroplasty and dual-energy CT. Conventional polyenergetic image (CI), orthopedic-MAR (OMAR), and virtual monoenergetic image (VMI, 50-200 keV) were tested for MAR. Quantitative analysis was performed in seven regions around the prostheses. Qualitative assessments included evaluation of the degree of artifacts and the presence of secondary artifacts. Results The lowest amount of image noise was observed in the O-MAR, followed by the VMI. O-MAR also showed the lowest artifact index, followed by high-keV VMI in the range of 120-200 keV (soft tissue) or 200 keV (bone). O-MAR had the highest contrast-to-noise ratio (CNR) in regions with severe hypodense artifacts, while VMI had the highest CNR in other regions, including the periprosthetic bone. On assessment of the CI of pelvic soft tissues, VMI showed a higher structural similarity than O-MAR. Upon qualitative analysis, metal artifacts were significantly reduced in O-MAR, followed by that in VMI, while secondary artifacts were the most frequently found in the O-MAR (p < 0.001). Conclusion O-MAR is the best technique for severe MAR, but it can generate secondary artifacts. VMI at high keV can be advantageous for evaluating periprosthetic bone.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.899-902
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• 2001

최근에 3 차원 가상 내시경은 환자에게 고통을 주지않고 내부 기관을 볼 수 있는 대체 방법으로 주목을 받고 있다. 인터랙티브(interacticve)한 렌더링 속도로 기관의 내부 표면을 도시하기 위해 표면 렌더링이 사용될 수 있지만, 이는 사실적인 렌더링 화질을 얻기에 부적합하고, 병변의 자세한 구조를 표현하기에 적합하지 않으며, 표면 뒤편의 조직을 도시할 수 없다. 이러한 이유로 볼륨 렌더링이 표면 렌더링의 대안으로 사용될 수 있지만 많은 계산량을 필요로 하므로, 대부분의 볼륨 렌더링 기반의 가상 내시경 시스템들은 부가적인 하드웨어나 큰 용량의 메모리를 사용한다. 본 논문은 가상 내시경을 위해 원근 레이 캐스팅 (perspective ray casting)을 이용한 볼륨 렌더링 기법의 고속화에 그 목적이 있다. 렌더링 속도를 높이기 위해서 서브샘플링(sub-sampling)된 화소들에 대해 레이 캐스팅을 수행하고, 이 과정에서 동시에 깊이 정보를 얻는다. 얻어진 깊이 정도로부터 남아있는 화소들에 대한 깊이 정보를 예측함으로써. 이를 레이 캐스팅의 속도 향상에 이용한다. 제안한 알고리즘을 이용하여 기존의 방법에 비해 기관지 내시경에서 77%, 대장 내시경에서 85%까지 렌더링 시간을 줄일 수 있고, 따라서 인터랙티브 렌더링이 가능하다.

• Radiation Oncology Journal
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• v.20 no.2
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• pp.165-171
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• 2002

Purpose : In order to perform craniospinal irradiation (CSI) in the supine position on patients who are unable to lie in the prone position, a new simulation technique using a CT simulator was developed and its availability was evaluated. Materials and Method : A CT simulator and a 3-D conformal treatment planning system were used to develop CSI in the supine position. The head and neck were immobilized with a thermoplastic mask in the supine position and the entire body was immobilized with a Vac-Loc. A volumetrie image was then obtained using the CT simulator. In order to improve the reproducibility of the patients' setup, datum lines and points were marked on the head and the body. Virtual fluoroscopy was peformed with the removal of visual obstacles such as the treatment table or the immobilization devices. After the virtual simulation, the treatment isocenters of each field were marked on the body and the immobilization devices at the conventional simulation room. Each treatment field was confirmed by comparing the fluoroscopy images with the digitally reconstructed radiography (DRR)/digitally composite radiography (DCR) images from the virtual simulation. The port verification films from the first treatment were also compared with the DRR/DCR images for a geometrical verification. Results : CSI in the supine position was successfully peformed in 9 patients. It required less than 20 minutes to construct the immobilization device and to obtain the whole body volumetric images. This made it possible to not only reduce the patients' inconvenience, but also to eliminate the position change variables during the long conventional simulation process. In addition, by obtaining the CT volumetric image, critical organs, such as the eyeballs and spinal cord, were better defined, and the accuracy of the port designs and shielding was improved. The differences between the DRRs and the portal films were less than 3 mm in the vertebral contour. Conclusion : CSI in the supine position is feasible in patients who cannot lie on prone position, such as pediatric patienta under the age of 4 years, patients with a poor general condition, or patients with a tracheostomy.