A study of machine enabled communication for the severely disabled patient, with reference to image processing techniques

M.Ing. (Mechanical Engineering)This research aims at identifying technologies which could be used to produce a communication aid for the speechless severely disabled person. A number of techniques are investigated which would enable the disabled to communicate by means of decoding eye movements. The tracking of the disabled's eye positions by means of two dimensional image processing and pattern recognition forms the basis of the input mechanism. A complete comparison between a number of candidate edge detectors is done to ensure that the system would function in as closeto real-time as is possible. Ancillary techniques such as a reduced grammar and a Markov model for letter posterior probabilities are developed and shown to improve the communication channel bandwidth. Simulated resultsshowwhat communication rate gains could be achieved. It appears that a possible communication aid could be built to perform at rates exceeding present day communication aids for the severely disabled at prices that could make such a device an economic possibility