Use of Electro-oculography as a Switch for Computer Assisted Communication in patients with Locked-in Syndrome

Computer assisted communication devices for patients with severe motor deficits require some form of "switch" activated by the patient to indicate their desired response. Typically these Assistive Technology (AT) systems have used electromyographic signals and eye-tracking to measure or record a response. However, in end-stage or severe neurological disease, patient may not have adequate motor nerve responses nor reliable control of visual fixation. Patient observation revealed that horizontal or vertical voluntary saccades are often preserved late in disease processes. We hypothesised that electrooculography (EOG) could be used to record a voluntary response and control AT.