• Biomedical Engineering Letters
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• 제8권4호
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• pp.345-353
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• 2018

This study suggested a new EMG-signal-based evaluation method for knee rehabilitation that provides not only fragmentary information like muscle power but also in-depth information like muscle fatigue in the field of rehabilitation which it has not been applied to. In our experiment, nine healthy subjects performed straight leg raise exercises which are widely performed for knee rehabilitation. During the exercises, we recorded the joint angle of the leg and EMG signals from four prime movers of the leg: rectus femoris (RFM), vastus lateralis, vastus medialis, and biceps femoris (BFLH). We extracted two parameters to estimate muscle fatigue from the EMG signals, the zero-crossing rate (ZCR) and amplitude of muscle tension (AMT) that can quantitatively assess muscle fatigue from EMG signals. We found a decrease in the ZCR for the RFM and the BFLH in the muscle fatigue condition for most of the subjects. Also, we found increases in the AMT for the RFM and the BFLH. Based on the results, we quantitatively confirmed that in the state of muscle fatigue, the ZCR shows a decreasing trend whereas the AMT shows an increasing trend. Our results show that both the ZCR and AMT are useful parameters for characterizing the EMG signals in the muscle fatigue condition. In addition, our proposed methods are expected to be useful for developing a navigation system for knee rehabilitation exercises by evaluating the two parameters in two-dimensional parameter space.

• 대한정형도수물리치료학회지
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• 제27권3호
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• pp.89-98
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• 2021

Purpose: The purpose of this study was to determine the effects of electromyography (EMG)-biofeedback based closed kinetic chain exercise (CKCE) on quadriceps muscle activity and dynamic balance ability in patellofemoral pain syndrome (PFPS). Methods: Thirty subjects with PFPS were included and they were divided into EMG-biofeedback using CKCE (Group I) and squat exercise using CKCE (Group II), each group consisted of 15 patients. Group I and Group II was performed by the patients for three times a week, for six weeks. sEMG was used to measure quadriceps muscle activity and star excursion balance test (SEBT) was used to measure dynamic balance ability. Results: According to the results of the comparisons between the groups, after intervention, quadriceps muscle activity and dynamic balance ability were significantly higher in Group I than in the Group II. Conclusion: Findings of this study suggest that EMG-biofeedback using CKCE that provides real-time biofeedback information on muscle contraction may have a beneficial effect on selective muscle strength of vastus medialis oblique muscle and dynamic balance ability in PFPS.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.738-741
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• 1988

In this paper, we deal with the movements identification of EMG signals by LPC cepstrum coefficients. Movements were identified by extration of characteristics of similar patterns in Euclid distance measurement method for EMG signals generated by voluntary contractions of subject's musculature. As number of coefficients is larger, we obtain the better rate of movements identification. By exact extraction of signals and decision of optimal coefficient, it is expected that these results will apply to prosthesis control in real-time.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.398-401
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• 1997

The EMG signal of spinal cord injured patient is very feeble because that the information from central nervous system is not sufficiently transmitted to molter neuron or muscle fiber. Therefore the observer can not observe contraction and relaxation movement of muscle from the raw EMG signal. In this paper, we propose the muscle contraction and relaxation pattern analysis method of spinal cord injured patient whose EMG signal is composed of the sum of motor unit action potential train with additive white Gaussian noise and impulsive noise. From the EMG model, we denoise impulsive noise using median filter which is a kind of nonlinear filter and the output of median filter is transformed to wavelet transform domain for denoising additive white Gaussian noise using threshold level removal technique. As a result, we can obtain the clear contraction and relaxation pattern.

• 대한임베디드공학회논문지
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• 제15권2호
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• pp.87-94
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• 2020

This paper introduces a method to control an industrial robot arm to imitate the movement of the human arm and hand using electromyography (EMG) signals. The proposed method is implemented on the UR3 robot that is a popular industrial robot and a MYO armband that measure the EMG signals generated by human muscles. The communications for the UR3 robot and the MYO armband are integrated in the robot operating system (ROS) that is a middle-ware to develop robot systems easily. The movement of the human arm and hand is detected by the MYO armband, which is utilized to recognize and to estimate the speed of the movement of the operator's arm and the motion of the operator's hand. The proposed system can be easily used when human's detailed movement is required in the environment where human can't work. An experiments have been conducted to verify the performance of the proposed method using the teleoperation of the UR3 robot.

• 한국지능시스템학회논문지
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• 제26권3호
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• pp.176-181
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• 2016

본 논문은 EMG(Electromyogram) 신호 기반의 웨어러블 기기를 이용하여 화재 감지 자율 주행 로봇을 제어하는 시스템을 제안하였다. 사용자의 EMG 신호를 읽어내기 위한 기기로는 Myo armband를 이용하였다. EMG 신호의 데이터를 블루투스 통신을 이용하여 컴퓨터로 전송한 후 동작을 분류하였다. 그 후 다시 블루투스를 이용하여 분류한 데이터 값을 uBrain 로봇으로 전송해 로봇이 움직일 수 있도록 구현하였다. 로봇을 조종 가능한 명령으로는 직진, 우회전, 좌회전, 정지를 구성하였다. 또한 로봇이 사용자로부터의 블루투스 신호를 받아오지 못하거나 사용자가 주행모드 변경의 명령을 내리면 로봇이 자율 주행을 하도록 하였다. 로봇이 주변을 돌아다니면서 적외선 센서로 화재를 감지하면 LED를 깜빡여 로봇 주변의 상황을 확인할 수 있도록 하였다.

• 한국멀티미디어학회논문지
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• 제6권1호
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• pp.48-57
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• 2003

본 연구는 hidden Markov model(HMM)과 유전알고리 즘을 갖는 MLP(multilayer perceptron) 합성 분류기를 이용한 근전 신호의 인식에 관한 연구이다. 제안된 기법에서 유전알고리즘은 전역적인 탐색으로 신경회로망의 최적의 초기 연결강도를 선택하는데, 이로 인하여 학습속도 및 인식률이 향상되게 된다. 근전 신호의 동적 특성은 연속 운동 인식처럼 신호의 길이 및 시작점과 끝점이 일정치 않고 시변성이 큰 경우에 반드시 고려되어야 하나, 일반 신경회로망에서는 이의 적용이 용이하지 않다. 따라서, 본 연구에서는 신호의 동적 특성에 대한 적응성을 갖는 HMM과 MLP 신경회로망을 결합시킨 구조를 갖는 인식기를 제안한다. 이러한 구조는 인식기의 입장에서 볼 때 HMM의 신호의 동적 특성에 대한 적응성과, MLP의 정적인 신호에 대한 우수한 분류력이 결합되어 동적인 신호에도 높은 인식율을 갖는 특성을 갖는다.

• Journal of Acupuncture Research
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• 제34권2호
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• pp.75-82
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• 2017

Objectives : The purpose of this study was to determine the electrical properties of the buccal area using facial surface electromyography (sEMG). Methods : This research was conducted on 44 healthy participants irrespective of their sex. Surface electrodes were attached to the midpoints of three imaginary lines connecting ST4 (Dicang) to ST6 (Jiache), ST4 to SI18 (Quanliao), and ST4 to the center point of SI18 and ST6. Then, the participants were trained in the movement that included a comprehensive action of buccal area. While the participants were performing the motion, sEMG values ($E_1$, $E_2$, $E_3$) and the distance change of the three imaginary lines ($D_1$, $D_2$, $D_3$) were measured. The data were statistically analyzed using SPSS ver. 22.0. Results : Significant differences were observed in the distance changes ($D_1$>$D_3$, $D_2$>$D_3$) and sEMG values ($E_1$<$E_2$<$E_3$). Moreover, there were positive correlations between $D_1$ and $E_1$, $D_2$ and $E_2$. Conclusion : We suggest that the measurement at ST4 to the center point of ST6 and SI18 with this motion would be adequate to check the electrical characteristics of the buccal area.

• 한국정보통신학회논문지
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• 제25권5호
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• pp.667-676
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• 2021

최근 우리나라의 청소년들은 스마트폰 과사용, 많은 학습량에 따른 신체활동 부족 등으로 인하여 자세 불균형의 위험에 노출되어있다. 또한 코로나 19로 인해 효과적인 비대면 운동 서비스에 대한 니즈가 증가하고 있는 추세이다. 이에 착안해 본 연구에서는 청소년들을 대상으로 둥근 어깨 개선의 효과를 제공하면서 비대면 서비스의 한계를 극복하기 위해 근전도 센서를 활용한 운동 서비스를 제안하고자 한다. 둥근 어깨를 개선할 수 있는 운동 프로그램을 구성하고, 효과적으로 운동할 수 있도록 근전도 센서를 연동한 어플리케이션을 구현하였다. 운동 프로그램은 4주 동안 타깃 근육 부위를 번갈아 가며 운동할 수 있도록 구성했고, 이에 따라 변화하는 근전도 수치를 측정하여 피드백을 제공할 수 있는 기능을 부가했다. 본 연구를 통하여 운동 기반의 자세 교정 디지털 서비스의 바탕을 제공하고, 이를 통하여 불균형한 신체를 개선함으로써 건강 증진의 가능성을 도모하고자 한다.

• 대한소아치과학회지
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• 제25권4호
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• pp.788-796
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• 1998

The purpose of this study was to investigate the effect of various electroacupuncture duration induced by acupuncture point-Zusanli ($S_{36}$) electrical stimulation on inhibition of amplitude of digastric electromyogram (dEMG) evoked by noxious electrical stimuli around the mental foramen. intraperitoneal sodium pentobarbital in an initial dose of 50mg/kg and maintenance doses of 4.5mg/kg/h were given through a cannula in the femoral vein using a constant infusion pump. A pair of stimulating electrodes were inserted for noxious stimuli around the mental foramen. An irritant electronic stimuli pulse (0.2 Hz, 0.1 ms duration) was produced with an intensity of about $1.5{\times}2$ times threshold for evoking the dEMG. The anterior belly of the digastric muscle was exposed and a pair of 0.1mm wire electrodes were inserted for dEMG recording. Acupuncture point stimulation on Zusanli (2 Hz, 250 ${\mu}s$, biphasic pulse, 2 V) was delivered by Dental Electronic Anesthesia (3M, U.S.A). For periods of electronic stimulation of 10, 20, and 30min, the amplitudes of dEMG were measured on the oscilloscope and on the monitor connected to the amplifier. The following results were obtained: The dEMG was decreased to 73.4% of that in the control set after 10 min electroacupunture stimulation (Group I); The dEMG was decreased to 77.1% (10min), 54.0.% (20min) of that in the control set after 20minutes of electroacupunture stimulation (Group II). The dEMG was decreased to 73.3% (10min), 61.9% (20min), 76.2% (30min) of that in the control set after 30 min of electroacupunture stimulation (Group III). From these results, it may be that in the electroacupuncture stimulation on the Zusnali resulted in a reduction of amplitude of dEMG and that the most effective electroacupuncture stimulation period was 20min.