Development of a compact-size and wireless surface EMG measurement system

This paper proposes a compact-size and a wireless surface EMG(electromyography) measurement system of a noninvasive type. The limitations of the current EMG sensor system include its large size, and the necessity of a wire. Therefore, this study focused on the development of a compact size preamplifier and wireless EMG measurement system. The EMG described herein is comprised of a preamplifier including an electrode for the measurement of the EMG signal, a main amplifier for signal processing, DSP(digital signal processor) processor for A/D conversion and digital signal processing, and a Bluetooth module for wireless communication. EMG signal obtained by the developed system results in better signal-to-noise ratio (SNR) compared to commercially available EMG system. This SNR of the developed system can be attributed to repeated signal processing on analog circuit and DSP, which reduces the size of the developed system. In our power spectral density, the EMG signal was distributed between approximately 20Hz and 400Hz. A Compact size and wireless surface EMG measurement system with high SNR can be useful for providing subjects comfort and consequently controlling external prosthesis.