Seat-driven Sit-to-stand Assistance System using EMG for Movement Prediction

We developed an assistive system that predicts Sit-to-stand (STS) movement in real time using the measurement results of trunk angle changes and lower limb muscle activities. We conducted an evaluation experiment to verify the effectiveness of the system. In the experiment, we measured the muscle activity when the system was driven at three different speeds, to confirm the change in the support effect depending upon the driving speed of the system. The results confirmed that the muscle activity decreased at all driving speeds when this system was used, compared to the unassisted STS movement. The reduction was largest at 1.5 times the normal speed, with a mean value of 36.9%. The evaluation results also confirmed that our system can assess when the system has provided excessive assistance.