Development and pilot testing of a new electromyography device - EMG Lavita

摘要

The mechanisms involved in muscle adaptations from different resistance training protocols are still not completely understood. The aim of this study is to develop an EMG device with a supervisory system that records intensity and time duration of concentric and eccentric phases of a muscular contraction. An electronic circuit was developed with an instrumentation amplifier INA118P, a bandpass filter 30 a 150 Hz, and a rectifier. The analog signal was converted to a digital signal using a 10-bit A/D converter that is part of the Arduino NANO (Atmega328p) microcontroller, which sends data via serial communication to a supervisory system that processes and displays data in graphs and tables. A usability system test was performed by four experts using the SUS scale. Also, the system validation test was performed by the researcher who developed the device by recording simultaneously EMG signals from his muscle fibers using two different electromyography devices - EMG Comercial and EMG Lavita. For this test, the researcher performed five data collections of ten repetitions of the elbow flexion movement with a 1-minute interval for each collection. A Pearson's correlation coefficient analysis was performed with the RMS values previously collected from the devices (r=0.86), which indicated a good to excellent correlation. The device developed in this study had a similar behavior than the commercial and validated tool; besides, all experts evaluated the system as satisfactory.