• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2013년도 추계학술발표대회
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• pp.1661-1664
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• 2013

본 연구는 만성 뇌졸중 환자 5 명을 대상으로 상지 운동(Affected hand의 주먹 쥐기/펴기운동)시 참가자의 운동의지와 운동 수행의 유무에 따라 차이가 있을 것을 가정하고, 운동 수행 및 운동의지가 존재하는 Active movement와 운동 수행을 하지만 운동의지가 없는 Passive movement, 운동 수행은 없지만 운동의지가 있는 Motor Imagery(MI)의 세가지 task에 따른 뇌파의 연결성을 비교하고자 한다. 이 때 EEG 영역 간의 연결성을 보기 위한 분석 방식 중 하나인 Phase locking value(PLV)를 통해 각 task 간의 차이를 비교 및 분석했다. 운동 수행은 동일하지만 운동의지 유무에 따른 차이는 Passive movement가 전반적으로 뇌 영역간 연결이 감소하고 Active movement가 motor task 시작 후 375ms를 기점으로 급격히 증가함을 보이는 데에서 발견할 수 있었으며, 운동 수행 유무에 따른 차이는 687.5ms 이후 Active movement에 비해 MI에서 뇌 영역 간 연결 수가 확연히 감소하는 데에서 큰 차이를 나타내었다. 이에 따라 본 연구에서는 만성 뇌졸중 환자의 상지운동 시의 motor task에 따른 EEG 영역간의 연결성을 토대로 운동의지 검출이 가능성이 있음을 밝혔다.

• 대한의용생체공학회:의공학회지
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• 제44권1호
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• pp.85-91
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• 2023

Stress urinary incontinence (SUI) occurs when abdominal pressure increases, such as sneezing, exercising, and laughing. Surgical and non-surgical treatments are the common methods of SUI treatment; however, the conventional treatments still require continuous and invasive treatment. Laser have been used to treat SUI, but excessive temperature increase often causes thermal burn on urethra tissue. Therefore, the optimal conditions must be considered to minimize the thermal damage for the laser treatment. The current study investigated the feasibility of the laser irradiation condition for SUI treatment using non-ablative 980 nm laser from a safety perspective through numerical simulations. COMSOL Multiphysics was used to analyze the numerical simulation model. The Pennes bioheat equation with the Beer's law was used to confirm spatio-temporal temperature distributions, and Arrhenius equation defined the thermal damage caused by the laser-induced heat. Ex vivo porcine urethral tissue was tested to validate the extent of both temperature distribution and thermal damage. The temperature distribution was symmetrical and uniformly observed in the urethra tissue. A muscle layer had a higher temperature (28.3 ℃) than mucosal (23.4 ℃) and submucosal layers (25.5 ℃). MT staining revealed no heat-induced collagen and muscle damage. Both control and treated groups showed the equivalent thickness and area of the urethral mucosal layer. Therefore, the proposed numerical simulation can predict the appropriate irradiation condition (20 W for 15 s) for the SUI treatment with minimal temperature-induced tissue.

• 한국수산과학회지
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• 제54권6호
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• pp.912-917
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• 2021

We investigated the distribution, molecular characteristics, and antimicrobial resistance of Vibrio vulnificus isolated from seawater at Gadeok Island, the Republic of Korea between June to October. Interestingly no isolates were detected between December to February. The detection rate of V. vulnificus was high (80-100%) from July to September 2019 and from June to September 2020. This coincided with the relatively low salinity of the seawater, which ranged from 7.8-29.9 practical salinity units for that period. Additionally, V. vulnificus had a high detection rate at sampling stations near the Nakdong river. The detection rates of virulence genes, such as vvhA, viuB, and vcgC, among the isolates were 97.1%, 44.1%, and 57.4% in 2019 and 100%, 43.0%, and 50.0% in 2020, respectively. Notably, viuB and vcgC were detected in V. vulnificus isolated between June to October when water temperature was above 20℃. The antimicrobial susceptibility analysis of 80 isolates revealed that most of the strains were susceptible to most antimicrobial agents. However, some isolates showed intermediate resistance to cefepime (18.8%), cefoxitin (58.8%), and erythromycin (22.5%). Of note, 3.8% of the tested strains were resistant to cefoxitin. The minimum inhibitory concentration of highly cefoxitin-resistant strains was determined to be less than 32 ㎍/mL.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.202-205
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• 2004

This paper represents the role of pinna in localizing target direction. Specially, this paper described what is the role of right-side pinna versus left-side pinna. In this experiment, one side of the pinna function was distorted intentionally by inserting a short tube on the ear canal. The localization error caused by right and left side pinna distortion was investigated. Since a laser pointer showed much less error (0.5%) in localizing target position than FASTRAK (30%) that has been generally used, it was used for the pointing task. It was found that harmonic components were not essential for the auditory target localization, however, non-harmonic nearby frequency components were more important to localize target direction of sound. We have found that the right pinna is one of the most important functions in localizing target direction and pure tone with only one frequency component is confusing for localization.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.206-210
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• 2004

This paper proposes a new training system for equilibrium sense using unstable platform. This training system for equilibrium sense consists of an unstable platform, a computer interface circuit and software program. Postural instability changes the weighting of different types of sensory information and the state of the equilibrium maintenance system. In order to improve the equilibrium sense, we developed software program such as a block game, sine curve training (SCT) and pingpong game using Visual C++. Using this system and training programs, we performed an experiment to train the equilibrium sense of a subject. To evaluate the effects of balance training, the time maintained on the target and the moving time to the target are measured. As a result, the moving time to the target and time to maintain cursor on the target improved through repeating equilibrium sense training. It was concluded that this system was reliable in the evaluation of equilibrium sense. We expect that this system might be applied to clinical use as an effective balance training system.

• 대한의용생체공학회:의공학회지
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• 제28권3호
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• pp.417-422
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• 2007

In this study, we investigated spatio-temporal eye-hand coordination by the "Global effect paradigm", a target-distracter configuration Global effect is observed a variety of visual tasks, for example, during rapid automatic tracking, scanning for target detail, and the comparison of target configurations. Global effect used to investigate eye-hand coordination with a task that presents a target close to a distracter. Eight young subjects participated in the experiments. The experiments consist of using a distracter less eccentric than the targe1 and using a distracter more eccentric than target. Each experiment consist of tasks which are making reference, pointing the target with watching visual stimulation(saccade) and pointing the target. The subject's task was to move towards the target as quickly as possible. We measured the eye movement by using EOG and the hand movement by using NDI Optotrak system. This study shows that eye and hand movement exists for global effect paradigm in spatio-temporal coordination.

• 로봇학회논문지
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• 제10권1호
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• pp.9-15
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• 2015

We present a robust power transmission lines detection method based on vanishing point estimation. Vanishing point estimation can be helpful to detect power transmission lines because parallel lines converge on the vanishing point in a projected 2D image. However, it is not easy to estimate the vanishing point correctly in an image with complex background. Thus, we first propose a vanishing point estimation method on power transmission lines by using a probabilistic voting procedure based on intersection points of line segments. In images obtained by our system, power transmission lines are located in a fan-shaped area centered on this estimated vanishing point, and therefore we select the line segments that converge to the estimated vanishing point as candidate line segments for power transmission lines only in this fan-shaped area. Finally, we detect the power transmission lines from these candidate line segments. Experimental results show that the proposed method is robust to noise and efficient to detect power transmission lines.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.202-205
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• 2005

The purpose of this work is to identify the characteristic of eye movement for visual training of the elderly. This investigation is to examine the relationship between the head and the eye motor system for the localization of visual target direction in three-dimensional space. All experiments were performed in a soundproof chamber. Twenty-one red LEDs (Light-Emitting Diode, Brightness: 20cd/$m^2$) arrayed in three lines on a half circle-surrounding panel are used. LEDs are horizontally 30 degree apart and vertically 20 degree apart from each other. The condition of stimulation is random and anti-saccade. Physiological parameter such as EOG (Electro-Oculography) was measured by BIOPAC system. We measure the mean latency time, which is the time from the start of visual stimulation to the response of the human body. The result shows that the mean latency time is short in the case of the condition of anti-saccade, the fixed head and a quarter visual stimulation. This finding can be used in developing programs for various visual improvements for the elderly by analyzing the characteristic of eye movement.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2440-2443
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• 2005

We propose a new early rehabilitation training system for postural control using a tilting bed and a force plate. The conventional rehabilitation systems for postural control cannot be applied to the patients lying in bed because the rehabilitation training using those systems is possible only when the patient can stand up by himself or herself. Moreover, there has not existed any device that could provide the sense of balance or the sensation of walking to the patients in bed. By using a tilting bed, a visual display, and a force plate, we have developed a new rehabilitation training system for balance control of the patients in bed providing sense of balance and the sensation of walking to the patient. Through the experiments with real people, we verified the effectiveness of the new early rehabilitation training system. The results showed that this system is an effective system for the early rehabilitation training and that our system might be useful as clinical equipment.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2444-2447
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• 2005

The purpose of this study was to analyze the gait motion of the aged with a lower limbs orthosis. The gait motion was analyzed with and without lower limbs orthosis using APAS 3D Motion Analysis System. The pattern of lower limbs motion was tracked based on four targets attached to the body of the subject. The targets were positioned at hip, knee, ankle, and foot. The parameters measured were the displacement, the velocity, and the acceleration of the four targets. The improvement in the measured values on the displacement and the velocity of the four targets were small with the orthosis due to inconvenience of wearing it, but the increase in the acceleration was large due to the elastic force of the rubber actuator. Especially, the increase of the acceleration of foot with lower limbs orthosis seems to help the gait motion of the elderly.