• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.631-634
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• 2000

In this paper, we propose a method for implementing a system for decoding the parameter data based on Facial Animation Parameter (FAP) developed by MPEG-4 Synthetic/Natural Hybrid Coding (SNHC) subcommittee. The data is displayed according to FAP with human mucle model animation engine. Proposed model has the basic properties of the human skin specified by be energy funtional for realistic facial animation.

• The Journal of Korea Robotics Society
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• v.17 no.3
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• pp.347-352
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• 2022

The paper presents how to update impedance control parameters for dual-arm manipulators using EMG signals and motions of the operator. Since the hand motions of the dual-arm are modeled to be the mass-spring-damper system in this paper, the impedance parameter update method is an important issue to reflect the operator's force. However, task space inertia to be used as the mass parameter goes to infinity if the manipulator approaches a kinematic singularity. To alleviate this issue, the impedance (stiffness and damping) parameters are divided with a diagonal element of the task space inertia. Also, the stiffness and damping matrices are updated using the normalized EMG signals captured from the operator's forearm. Through this process, the motion of the dual-arm manipulator is more stabilized even though it approaches the kinematic singularity.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.1967-1974
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• 1991

When the functional electrical stimulation is employed to recover mobility to the plegic, it is very important to understand functions of the selected muscles. I have investigated how a muscle acts to accelerate the body segments, since the body segements are connected by joints so that contraction of a muscle not only rotates the segments to which it is attached but also causes other segments to rotate by creation a reaction force at every joint, which is called the inertial coupling. I found that a single-joint muscle always acts to accelerate the spanned joint in the same direction as the joint torque produced by the muscle. However, a double-joint muscle can act to accelerate the spanned joint in the opposite direction to the joint torque produced by the muscle depending on (1) the body position, (2) the body-segmental parameters, and (3) the type of the movement. Investigating the condition number of the inertia matrix of the body-segmental model gave us some insights into how controllable the body-segmental system is for different values of the factors mentioned above. The results suggested that the upright position is the most undesirable position to independently control the three segments(trunk, thigh and shank) and that the controllability is the most sensitive to variation of the shank length and the trunk mass, which implies that accuracy is required particularly when we estimate these two body-segmental parameters before the paralyzed muscles are innervated by using electrical stimulation.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2699-2701
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• 2002

In this study, a system for measurement of impedance (transmission parameter) on the human muscle was constructed. The system composed of the stimulating part for input with milli-voltage and the measuring part for measurement of transmission voltage in human muscle. As a result of this experiment, the frequency characteristic of each subject represent that the transmission voltage goes up in spite of a constant input voltage according to frequency (1Hz -50kHz) increment. Namely, the amplitude of input signal was not reflected but frequency was reflected on the measured results. This result be estimated that the proposed system is able to measure passive electrical characteristic of human body.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.6-9
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• 1996

In this paper, we attempted to analyze the contraction patterns of elbow flexor muscle during isometric, concentric and eccentric contraction. The analysis parameters are consisted of Sequency domain parameters (mean frequency, median frequency, skewness, kurtosis) and time domain parameters (zero crossing, positive maxima, integrated EMG). As a results, the analysis parameters have specific trends for muscles, muscle contraction patterns, muscle contraction angles. Especially, at the time domain analysis, IEMG is a dominant parameter for analysis of activation patterns, and the skewness, kurtosis are useful parameters for functional recognition.

• Journal of Korean Orthopaedic Sports Medicine
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• v.9 no.2
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• pp.104-108
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• 2010

Purpose: To evaluate the correlation between Korean Shoulder Scoring System and Isokinetic muscle strength test for allowance of the return to unrestricted activities after rotator cuff disease treatment. Materials and Methods: This study examined 59 patients with impingement syndrome and 36 patients with rotator cuff tear. KSS and isokinetic muscle strength were analyzed and we sought to evaluate the correlation between total score or each functional parameter scores of KSS and isokinetic muscle strength deficit with Pearson's correlation test. Results: We found a weak negative correlation between and the total KSS score and the endurance test as well (r<0.346). The correlation between the manual muscle test of KSS and isokinetic strength deficits was not significant (p>0.05). Conclusion: The isokinetic muscle strength deficit had a weak correlarion between total score or the edurance test of KSS. Our results suggest that the Isokinetic muscle strength test may be needed for return to normal activity after treatment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.865-866
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• 2008

• Journal of Biomedical Engineering Research
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• v.22 no.3
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• pp.269-273
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• 2001

Proper determination of pacing threshold is important for patient safety and pacemaker longevity. In general, cardiac muscle contractions caused by pacing pulses are verified by observing the morphology of surface ECG displayed on a monitor. In this study, a method of automatic pacing threshold determination based on morphological difference between intrinsic and paced ECGs was developed. First, characteristics of intrinsic ECG and paced ECG were analyzed in time and frequency domain and a proper discrimination parameter was extracted. Then, the automatic capture verification method based on the parameter was developed and applied to 23 pacemaker patients. The selected parameter was the area of ventricular depolarization wave during 80ms after pacing stimulus. It was found that the method was reliable and effective in identifying paced ECG and, thereby, determing a proper pacing threshold.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.165-166
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• 1998

A multi-parameter neuro muscular electrical simulator (NMES) system was developed to be used to find the optimal parameter condition in obtaining maximum muscle power and minimal fatigue. Since the performance of NMES is mainly determined by the characteristic of its output-stage circuit, we implemented 3 different circuits and compared output characteristics of them. Three amplifier circuits are; 1) a resonant switching converter, 2) a linear amplifier with a transformer, and 3) a step-up DC/DC converter with a high-voltage linear amplifier. Experimental results showed that the step up DC/DC converter with a high-voltage linear amplifier has the best performance.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.11
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• pp.1051-1058
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• 2014

In this study, we investigated the improvement effect of obesity by treatment with a developed low frequency electrical stimulation system. Thirty female in their 20's as an experiment subjects divided 3 groups(control, commercialized device, developed device) were treated with electrical stimulation on abdomen for 4 weeks. The body weight, body mass index(BMI), waist-hip ratio(WHR), muscle strength, muscle(transverse abdominis(TrA), internal obliquus abdominis(IO), external obliquus abdominis(EO)), fat thickness and abdominal surface temperature were measured by electromyogram(EMG), ultrasound and digital infrared thermal image(DITI). In the result, the body weight and BMI were decreased. Subcutaneous abdominal fat were significantly reduced after 4 weeks. The muscle strength and TrA muscle thickness was increased 13.2%(p<0.05), and 35.5%, respectively. The fat thickness showed decrease in abdomen (p<0.05). Infrared measurement on abdominal surface temperature as a parameter of improvement in blood circulation was significantly increased(p<0.05). Therefore, the low frequency stimulation showed positive effects on parameters of the obesity improvement.