Optical communication aids in rehabilitation.

Two types of low-cost optical communication aids for non-vocal paralyzed patients are described: one based on reflection via mirrors and the other based on refraction via prisms. The recognition by the partner, when the handicapped person looks straight via the mirror/prism into his eyes, is crucial in the selection of the corresponding symbol in this communication process. The configurations in which the mirrors/prisms are arranged in aids of one- or two-dimensions, respectively. Preceding the choice of an advanced eye-controlled aid, eye defects can be detected using two-dimensional aids. Both types of optical communicators have been used in rehabilitation. The prism-aids appeared to be preferable to mirror-devices and to ETRAN-window in the communication process for speech replacement or in playing simple games.