Hands-free assistive technology employing brain wave activity for the severely disabled: Innovation and limitations

© 2014 by Nova Science Publishers, Inc. All rights reserved. People living with a severe disability such as chronic spinal cord injury can suffer personal and social consequences that substantially diminish wellbeing. One potential negative impact is the loss of the independent capacity to control devices in their immediate environment (such as a television or computer) using their hands and fingers. Consequently, assistive technology research has focussed on restoring a degree of independence by developing novel interface systems that restore some measure of technological control. There are a number of creative "hands free" control systems being developed, including systems that utilize voice, muscle, brain activity, head motion, eye blink, breath, and chin. However, rarely has the efficacy of these systems been scientifically established. This chapter will present an overview of these systems, and present results of a novel brain signal based interface system (called Mind Switch) that utilizes voluntary changes in electroencephalography (EEG) to activate and control electrical devices. Results of a clinical field trial with this system with 10 participants (mean age of 42.9 years) who had very limited movement from the neck down (six with tetraplegia and one each with polio, muscular atrophy, multiple sclerosis and cerebral palsy), showed they were able to turn their own television on and off, change channels and volume, with few errors and within minutes using their brain signals. We also present results of recent research designed to minimise participant's errors of choice through smart processing of the EEG signal using fractal analysis, and strategies for improving participants switching and activation control when they become tired. Implications and limitations of "hands-free" brain signal based assistive technology are discussed