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 a nd converts them to either a 'yes' signal (produced by one lateral eyeball movement) or a 'no' signal (produced by two successive lateral eyeball move ments) using a video camera placed outside the patient's visual field. The patient is thus able to concentrate on performing a task without any intrus ion from the detection system. Once the setting conditions of the device ha ve been selected, there is no need for any resetting, as the patient is usa ble to move his body. In addition to playing television games, the child ca n use the device to select television channels, compose music, and learn wr itten Japanese and Chinese characters. This seems to broaden the patient's daily world and promote mental development.