Assistive Pointing Device Based on a Head-Mounted Camera

This paper introduces and validates the performance of an alternative input device for people with limited hand/arm movement and control. A summary is provided of the current state of the art in alternative input devices. Based on this, a low-cost solution is proposed that allows for 1) low latency and high operating speed and accuracy, 2) use from different viewing angles without recalibration, and 3) the ability to seamlessly control multiple devices. A prototype of this system was built and tested to determine the accuracy of the system (using a pan-tilt system), and to analyze the performance of the system compared to the state of the art (through user tests, based on the ISO 9241-411 test). The proposed system allows for great accuracy (sigma(X) = 0.28 px, sigma(Y) = 0.29 px, sigma(XY) = 0.02 px), a decent performance compared to the state of the art (throughput = 1.52 bits/s, error rate = 31%), and good results in the ISO 9241-411 independent rating scale. The results from the performed experiments show that the proposed system leads great promise in real-world applications. A low-cost head-mounted camera could be used as an alternative human interface device for people with limited hand/arm movement and control, allowing them to participate in the ongoing trend of computing devices gaining importance in our everyday activities.