Communication aid system for users with physical impairments

Abstract

For some physically-disabled persons, the conventional computer keyboard may be inappropriate as a usable communication device. They instead require an assistive tool for entering text into a computer or for word-processing for purposes of augmentative and alternative communication in their daily lives. In this study, Morse code is selected as one possible adapted access communication method for persons with impaired hand coordination and limited dexterity. Inherently, a stable switch activation rate is strictly required for the most accurate recognition of Morse code. However, because maintaining a stable switch activation rate is a challenge for many persons who are physically disabled, automatic recognition of Morse code with standardized computer programs is difficult. Therefore, a suitable adaptive automatic recognition method is needed. This study presents a least-mean-square algorithm applied to adaptive Morse code recognition. Four processes are involved in this adaptive Morse code recognition method: space recognition, tone recognition, adaptive processing, and character recognition. Statistical analyses demonstrated that the recognition rate of the proposed method resulted in an 83% improvement over alternative methods described in previous literature.