Amyotrophic lateral sclerosis: Ergonomic approach of patient assistance

The general purpose of this paper is to introduce assistive technologies from the point of view of ergonomics. This approach is based on an appropriate understanding of the requirements of people with motor impairments, to design augmentative or palliative forms communication. First, the authors summarise of the main features of Amyotrophic Lateral Sclerosis (ALS) and its medical, psychological and technological approach, with a view to having a better understanding of this disease and reducing suffering. Second, the paper presents interactive telethesis and its functions. The user can have some control on some aspects of his/her immediate environment : 1 / controlling alarm signals : bell-warning medical staff; 2 / text interfacing: reading with integrated page markers and writing/editing text with online assistance for ward prediction (currently based on a 90 000 word lexicon); 3 / television remote control : channel and volume control; 4 / CD reader control to listen to music and audio books; 5 / using pre-recorded sentences to communicate with nurses, Friends and relatives. The objective of the investigation is to remedy the gradual deterioration of the patient's interactive functions by designing new procedures for interaction that ave compatible with the central cognitive process, and to alleviate practical diffculties in the last few years of life for people suffering motor impairments. Telethesis can be viewed as an extension of interactive users who have lost most of their motion capacity. In fact, telethesis tends to support the development of intellectual, affective and social stimuli. Third, the paper presents the results of a 6-month analysis and sequential recording (240 hours of technical monitoring) of all the actions performed by a patient. The data collected made it possible to optimise the man-machine interface and to evaluate the impact of telethesis on the emotional ease experienced by a patient affected by Ars. The results show that assistive technologies designed from the viewpoint of ergonomics and on the basis of a better understanding of the stream of consciousness developing in the final years of life make it possible, not only to compensate partly for the physical deterioration, but also to develop adaptive strategies. Our findings served as a basis to elaborate a type of palliative communication to be implemented interactively supported by powerful mechanisms to cope with the hardships associated with this crippling disease.