• Korean Journal of Clinical Laboratory Science
• /
• v.51 no.2
• /
• pp.185-190
• /
• 2019

Compression stockings are widely used for prevention of varicose vein. Depending on manufacture, there are diverse types of compression stockings available. Most common type of compression stocking might be the one cover calf of a lower leg which has 20~30 mmHg pressure. Despite being widely used, possible side effects that may occur by wearing compression stockings have not been studied much. We analyzed for a long wearing effect of compression stocking. Participants wore the compression stocking over one leg for 7 days. During the period, all the participants did their ordinary works wearing the compression stocking. Electrocardiogram (ECG), ankle-brachial index (ABI), blood pressure (BP), and electromyogram (EMG) were measured at 0 day, 3rd day and 7th day. There was no effect of wearing compression stockings from ECG, ABI or BP. Only EMG that was measured on the covered muscle increased proportionally to the wearing time. Interestingly, EMG from the opposite leg that had never been covered by compression stocking decreased in proportion to the wearing date. These results suggest wearing a compression stocking for varicose vein may cause unintentional increase or decrease of EMG from the wearing or non-wearing legs, respectively.

• Proceedings of the KOSOMBE Conference
• /
• v.1991 no.05
• /
• pp.65-70
• /
• 1991

A hybrid model which uses a probabilistic model and a MLP(multi layer perceptron) model for pattern recognition of EMG(electromyogram) signals is proposed in this paper. MLP model has problems which do not guarantee global minima of error due to learning method and have different approximation grade to bayesian probabilities due to different amounts and quality of training data, the number of hidden layers and hidden nodes, etc. Especially in the case of new test data which exclude design samples, the latter problem produces quite different results. The error probability of probabilistic model is closely related to the estimation error of the parameters used in the model and fidelity of assumtion. Generally, it is impossible to introduce the bayesian classifier to the probabilistic model of EMG signals because of unknown priori probabilities and is estimated by MLE(maximum likelihood estimate). In this paper we propose the method which get the MAP(maximum a posteriori probability) in the probabilistic model by estimating the priori probability distribution which minimize the error probability using the MLP. This method minimize the error probability of the probabilistic model as long as the realization of the MLP is optimal and approximate the minimum of error probability of each class of both models selectively. Alocating the reference coordinate of EMG signal to the outside of the body make it easy to suit to the applications which it is difficult to define and seperate using internal body coordinate. Simulation results show the benefit of the proposed model compared to use the MLP and the probabilistic model seperately.

• Journal of Korean Physical Therapy Science
• /
• v.9 no.3
• /
• pp.77-87
• /
• 2002

The purpose of this study was to compare the changes of muscle activities in deltoid with those in supraspinatus using electromyography(EMG) while subjects abducted their shoulder to different angles with different resistance. Methods : 20 volunteers who were comprised of 10 males(mean age: $21.2{\pm}2.0$) and 10 females(mean age: $20.2{\pm}1.6$) were collected. Surface electrodes were attached on deltoid and supraspinatus muscle for recording. Each reference electrode was located 3 cm to the each recording electrode. Muscle action potentials were recorded with changing the angle of shoulder abduction, $30^{\circ}$, $60^{\circ}$, $90^{\circ}$. This procedure was repeated with different resistance 0 pound, 2 pounds, 4.5pounds. The angle of shoulder abduction was determined by clinical goniometer. SPSS(Statistical Program for Social Science)/WIN 10.0 was used for statistics. Analysis included ANOVA, T-test. Results : The following results were obtained in this study. 1. There was significant differences during isometric shoulder abduction $30^{\circ}$, $60^{\circ}$, $90^{\circ}$ comparing muscle activity in deltoid and supraspinatus muscles at 0 pound, 2pound, 4.5pound resistance(p<0.05). 2. There was no useful significant in the deltoid and supraspinatus muscles activity EMG compared by physical condition. 3. Their was significant in the deltoid EMG compared by gender t=-5.41, P<0.01, but no difference in the supraspinatus EMG(P=0.333 >a=0.05). Conclusions: There are many previous studies on influence of shoulder angles and speeds of muscle activity. However most of them placed the focus on isotonic or isokinetic exercise, or shoulder function. But this study was done during isometric exercise, which is better for early assessment and treatment for injured patients. There is strong relationship between the shoulder angle with resistance in deltoid supraspinatus muscle activity. We conclude that it is important to apply isometric shoulder abduction exercise with correct angle and resistance especially in early stage.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.12
• /
• pp.129-137
• /
• 2013

As the usage of computer based systems continues to increase in our normal life, there are constant efforts to enhance the accessibility of information for handicapped people. For this, it is essential to develop new interface ways for physical disabled peoples by means of human-computer interface (HCI) or human-machine interface (HMI). In this paper, we developed HMI using electromyogram (EMG) and electrooculogram (EOG) for people with physical disabilities. Developed system is composed of two modules, hardware module for signal sensing and software module for feature extraction and pattern classification. To maximize ease of use, only two skin contact electrodes are attached on both ends of brow, and EOG and EMG are measured simultaneously through these two electrodes. From measured signal, nine kinds of command patterns are extracted and defined using signal processing and pattern classification method. Through Java based real-time monitoring program, developed system showed 92.52% of command recognition rate. In addition, to show the capability of the developed system on real applications, five different types of commands are used to control ER1 robot. The results show that developed system can be applied to disabled person with quadriplegia as a novel interface way.

• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.8
• /
• pp.749-754
• /
• 2015

The purpose of this study is to conduct a comparative analysis of the right shoulder's muscle activity when lifting ipsilateral and contralateral legs during the Push Up Plus (PUP) exercise, which is a typical shoulder stabilizing exercise, and to provide effective data for a shoulder stabilization exercise. Upper trapezius, lower trapezius, levator scapula, supraspinatus, infraspinatus, deltoid posterior, serratus anterior and pectoralis major, which are eight main muscles of a shoulder, were analyzed for the left and right leg lifting by using an electromyogram (EMG). The study revealed that the muscle activities of the right shoulder's upper trapezius, levator scapula, supraspinatus, serratus anterior and pectoralis major were higher when lifting an ipsilateral (right side) leg, compared to lifting a contralateral (left side) leg. Therefore, lifting an ipsilateral leg can be an effective method for enhancing the maneuverability (mobility) of the right shoulder when lifting a single leg.

• Journal of Korean Institute of Industrial Engineers
• /
• v.24 no.2
• /
• pp.261-278
• /
• 1998

The paper represented the lower extremity muscle model as four rigid-body segments: trunk, shank, and foot. We transformed their tibial data into our shank data by rotating their tibial X and Y axes by 5.483 degrees, so the revised coordinate data used to translating the origin of their tibial reference frame to our shank reference frame. According to weight of subject, physiological cross-setional area(PCSA) of each lower extremity muscle was calculated by scaling those data by Brand. The objectives of this paper are to investigate the variations of the recruitment patterns of the lower extremity muscles, and to analyze the changes of the role assigned to each muscle during the seated foot operation. For exertion levels, the transition point of type F motor unit of each muscle is inferred by analyzing the electromyogram at the seated postures. Also, for predetermined seated foot operations exertion levels, the recruitment pattern and the changes of the role assigned are identified in the continuous exertion, by analyzing the electromyogram changes due to the accumulated muscle fatigue. This study can be used to design and to assess the pedals and foot-related equipments design.

• Journal of Korea Entertainment Industry Association
• /
• v.13 no.8
• /
• pp.525-530
• /
• 2019

Electroencephalography(EEG) studies that have been in clinical research since the discovery of brainwave have recently been developed into brain-computer interface studies. Currently, research is underway to manipulate robot arms and drones by analyzing brainwave. However, resolution and reliability of EEG information is still limited. Therefore, it is required to develop various technologies necessary for measuring and interpreting brainwave more accurately. Pioneering new applications with these technologies is also important. In this paper, we propose development of a personal authentication system fit for lifecaretainment based on EEG. The proposed system guarantees the resolution and reliability of EEG information by using the Electrooculogram and Electromyogram(EMG) together with EEG.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.10
• /
• pp.1345-1350
• /
• 2010

Sit-to-stand movement is a basic movement in daily activities. On the basis of this movement, the biomechanical functions of a person can be evaluated. The study of the joint kinematics, moment, and muscle coordination is necessary to understand the characteristics of the sit-to-stand movement. We have developed a motion-based program for inverse dynamics analysis and the electromyogram-based program for muscle force prediction. The joint kinematics and the kinetic results estimated on the basis of obtained motion data, ground reaction force, and electromyogram signals were compared with those reported in previous studies, and the muscle forces determined by the two methods were compared with each other. The methods and programs developed in this study can be used to understand biomechanics and muscle coordination involved in basic movements in daily activities.

• Journal of Multimedia Information System
• /
• v.7 no.2
• /
• pp.189-196
• /
• 2020

We have developed a device for recording biological data by inserting three electrodes and a needle with an angular velocity sensor into the moth for the purpose of measuring the electromyogram of the flapping and the corresponding lift force. With this measurement, it is possible to evaluate the moth-physiological function of moths, and the amount of pesticides that insects are exposed to (currently LD50-based standards), especially the amount of chronic low-concentration exposure, can be reduced the dose. We measured and recorded 2-channel electromyography (EMG) and angular velocity corresponding to pitch angle (pitch-like angle) associated with wing flapping for 100 sweet potato hawkmoths (50 females and 50 males) with the animals suspended and constrained in air. Overall, the angular velocity and amplitude of EMG signals demonstrated high correlation, with a correlation coefficient of R = 0.792. In contrast, the results of analysis performed on the peak-to-peak (PP) EMG intervals, which correspond to the RR intervals of ECG signals, indicated a correlation between ΔF fluctuation and angular velocity of R = 0.379. Thus, the accuracy of the regression curve was relatively poor. Using a DC amplification circuit without capacitive coupling as the EMG amplification circuit, we confirmed that the baseline changes at the gear change point of wing flapping. The following formula gives the lift provided by the wing: angular velocity × thoracic weight - air resistance - (eddy resistance due to turbulence). In future studies, we plan to attach a micro radio transmitter to the moths to gather data on potential energy, kinetic energy, and displacement during free flight for analysis. Such physiological functional evaluations of moths may alleviate damage to insect health due to repeated exposure to multiple agrochemicals and may lead to significant changes in the toxicity standards, which are currently based on LD50 values.

• Journal of the HCI Society of Korea
• /
• v.1 no.2
• /
• pp.9-17
• /
• 2006

We propose an EMG-based input interface technology for helping the tetraplegic to utilize mouse, keyboard and power wheelchair. Among possible actions for the tetraplegic utilizing these devices, teeth-clenching is chosen as an input action. By clenching left, right or both teeth, and controlling the clenching duration, several input commands for utilizing the devices can be conducted. EMG signals generated by teeth-clenching are acquired around one's left and right temples and they are used as control sources for utilizing the devices. We develop signal acquisition devices, signal processing algorithms, and prototype systems such as power wheelchair control, mouse control, and game control. Our experimental results with the tetraplegic show that the proposed method is useful for utilizing the devices.