New ocular movement detector system as a communication tool in ventilator-assisted Werdnig-Hoffmann disease

A non-contact communication system was developed for a ventilator-assisted patient with Werdnig-Hoffmann disease who had lost all voluntary movements except for those of the eye. The system detects the extraocular movements and converts them to either a 'yes' signal (produced by one lateral eyeball movement) or a 'no' signal (produced by two successive lateral eyeball movements) using a video camera placed outside the patient's visual field. The patient is thus able to concentrate on performing a task without any intrusion from the detection system. Once the setting conditions of the device have been selected, there is no need for any resetting, as the patient is usable to move his body. In addition to playing television games, the child can use the device to select television channels, compose music, and learn written Japanese and Chinese characters. This seems to broaden the patient's daily world and promote mental development.