• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1588-1593
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• 2008

This paper describes a real-time isometric pinch force prediction algorithm from surface electromyogram (sEMG) using multilayer perceptron (MLP) for human robot interactive applications. The activities of seven muscles which are observable from surface electrodes and also related to the movements of the thumb and index finger joints were recorded during pinch force experiments. For the successful implementation of the real-time prediction algorithm, an off-line analysis was performed using the recorded activities. Four muscles were selected for the force prediction by using the Fisher linear discriminant analysis among seven muscles, and the four muscle activities provided effective information for mapping sEMG to the pinch force. The MLP structure was designed to make training efficient and to avoid both under- and over-fitting problems. The pinch force prediction algorithm was tested on five volunteers and the results were evaluated using two criteria: normalized root mean squared error (NRMSE) and correlation (CORR). The training time for the subjects was only 2 min 29 sec, but the prediction results were successful with NRMSE = 0.112 ${\pm}$ 0.082 and CORR = 0.932 ${\pm}$ 0.058. These results imply that the proposed algorithm is useful to measure the produced pinch force without force sensors in real-time. The possible applications include controlling bionic finger robot systems to overcome finger paralysis or amputation.

• PNF and Movement
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• v.9 no.1
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• pp.47-54
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• 2011

Purpose : The purpose of this study was to investigate muscle activity of affected lower extremity by unaffected lower extremity exercise and tried to examine muscle activity of affected lower extremity of hemiplegic patients were caused by stroke according to wearing single strap hemisling or non-wearing. Methods : We measured muscle activity of affected lower extremity when wearing single strap hemisling to affected lower extremity or non-wearing according to unaffected lower extremity used MP 150 Eletromyogram. Results : 1) Muscle activity of gluteus medius muscle was the highest D1 before wearing single strap hemisling. 2) Muscle activity of hamstring muscle was the highest D3 after wearing single strap hemisling. 3) Muscle activity of quadriceps muscle was the highest D5 after wearing single strap hemisling. 4) Muscle activity of tibialis anterior muscle was the highest D1 after wearing single strap hemisling. 5) Muscle activity of soleus muscle was the highest D2 before wearing single strap hemisling. Conclusion : Wearing single strap hemisling of hemiplegic patients had effect on muscle activity of gluteus medius but didn't effect gluteus medius, hamstring, quadriceps, tibialis anterior muscle and soleus muscle.