Wearable EMG-based HCI for Electric-Powered Wheelchair Users with Motor Disabilities

Electromyogram (EMG) signal generated by voluntary contraction of muscles is often used in rehabilitation devices because of its distinct output characteristics compared to other bio-signals. This paper proposes a wearable EMG-based human-computer interface (HCI) for electric-powered wheelchair users with motor disabilities by C4 or C5 level spinal cord injury. User expresses his intention as shoulder elevation gestures, which are recognized by comparing EMG signals acquired from the levator scapulae muscles with a preset threshold value. In this paper HCI command to control electric-powered wheelchair is made of combinations of left-, right-and both-shoulders elevation gestures. The proposed wearable HCI hardware consists of two active surface electrodes, a high-speed micro-controller, a Bluetooth module, and a battery. Experimental results using the wearable EMG based HCI and the electric-powered wheelchair developed show the proposed wearable EMG-based HCI is feasible for the users with severe motor disabilities.