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.

This paper proposes an intelligent robotic wheelchair with user-friendly human-computer interface (HCI) based on electromyogram (EMG) signal, face directional gesture, and voice. The user's intention is transfered to the wheelchair via the HCI, and then the wheelchair is controlled to the intended direction. Additionally, the wheelchair can detect and avoid obstacles autonomously using sonar sensors. By combining HCI into the autonomous functions, it performs safe and reliable motions while considering the user's intention. The experimental results in the crowded environment show that the proposed robotic wheelchair is feasible for the disabled and the elderly with severe motor disabilities.