International Journal of Physical Medicine & Rehabilitation
Open Access

Abstract

Low-Cost 2-Channel Electromyography Telemeter using a Personal Computer Microphone Port

Risa Suzuki, Shuntaro Okazaki, Mayu Kuniya and Yoshihiro Muraoka

Objective: For the convenient use of electromyography devices in physical rehabilitation during locomotion, we developed a simple, low-cost 2-channel electromyography telemeter (LC-EMGT) that can be connected wirelessly with a personal computer (PC) microphone port.

The aim of this study was to verify whether the performance of our LC-EMGT fulfills the need for monitoring EMG during locomotion of patients in rehabilitation. For this purpose, we compared the performance of our LC-EMGT with an existing EMG device (NeuropackΣ).

Methods: Muscle activity of the left and right vastus medialis were recorded when the participant repeated a standing-up movement for 10 seconds at 55-bpm speed. The EMG signal was simultaneously recorded by the LCEMGT and NeuropackΣ. We compared the waveform of these EMG signals and their root mean squared signals in appearance and by cross-correlation analysis. Also, we monitored the orthopedic patients’ EMG waveforms during standing-up and ascending stairs.

Results: The cross-correlation analysis demonstrated an approximately 170-ms delay in EMG measurement by LC-EMGT due to the wireless signal transformation. Meanwhile, the amplitudes of the waveforms in the LC-EMGT were almost equal to those of the NeuropackΣ. In addition, with the LC-EMGT, we could visually monitor EMG waveforms of the patients during standing-up and stair climbing on-line using a PC.

Conclusion: Consequently, the LC-EMGT was as reliable as the existing EMG device at monitoring EMG signals and is available as an EMG monitor in real-time. The LC-EMGT is cost-effective, convenient, and may be generally used in various clinical and sports situations.