Interfaces for tetraplegic people – review of solutions supporting activities of daily living

Abstract

Abstract Currently, a disabled person can participate in social life and proceed with independent individual development with the assistance of intelligent support from modern technology. This paper reviews various approaches and recent achievements in designing and prototyping of interfaces for tetraplegic people originating from Biocybernetics Laboratory AGH. After a short review of other available systems, three categories of activities of daily living (ADL)-supporting solutions are presented: input devices, control software, and stand-alone systems. As a result of testing other alternatives such as touchpad, tongue presspad, eye tracker, blow sensor, and direct sensor of brain electrical activity, joysticks were selected as preferable input devices. They are free from hygienic issues, tolerant to involuntary use or excessive force, and easily operable by using the chin or lips. The operational flexibility required for personalization of input devices is achieved with dedicated software defining the rules of interpretation of operators’ motions. To adapt the final signal to the specificity of a supported human, the interpretation process takes into account the identification of gesture, its duration, and coincidence. The paper also presents two stand-alone systems dedicated to supporting the selected ADL. One of them is a smart interface for infrared-based remote control of home appliances, and the second is a joystick-based emulator of a computer mouse. Both devices provide a learning mode that allows for adaptation to the particular environment (i.e. set of devices to be controlled) and specific abilities of their human operator.