Real Time Control of Virtual Menu Based on EMG Signal from Jaw

Researches on numerous methods to link humans and machines have long been conducted to help people in running their daily activities. This research designed EMG signal controlled virtual menu. There were 9 menu items inside which were arranged in a 3x3 matrix. An EMG signal from the jaw was used to operate the virtual menu. There were five commands to operate the virtual menu: selecting menu items, up searching, down searching, left searching and right searching. Threshold value of amplitude was used to recognize contraction of the jaw. The duration of the EMG signal exceeding the threshold value called the Timer was used to produce five commands. Fourteen volunteers examined the system. The result shows that a 100 mu V threshold for amplitude and 5 Timers used in this research can recognize 98.8% of 840 activities. Six scenarios of tasks from three trajectories were designed to be completed by operators. The result shows that operators can finish all the tasks. The real time spent by operators for those activities was nearly the same as the designed estimated time. The virtual menu was also reviewed based on the operation tiredness, the difficulty in executing selecting and searching commands and the comfort of having the electrodes attached to the jaw skin. Almost 80% of the operators could operate this device without a negative issue. But attaching the electrodes to the jaw made a challenge because it caused discomfort on the operators.