A general purpose electromechanical simulator for switches used in the rehabilitation of communication-impaired people

Niamh Connolly, University College Dublin
Ted Burke, Dublin Institute of Technology
Annraoi De Paor, University College Dublin

In Advances in Electrical and Electronic Engineering (Slovakia), Vol.3,no.2, May, 2004, pp.201-204. Also presented at Elektro'04, University of Zilina, Slovakie, May 25-26, 2004.


The importance of simple mechanical switches in rehabilitation cannot be overstated, particularly in the facilitation of communication and control by people with profound physical disabilities. Many communication and control systems are designed to be operable using a single switch (or a small number of switches). A crucial step in the tailoring of a system to a patient who will operate it in this way is the selection of an appropriate switch, according to their physical abilities. We present a prototype switch simulator, capable of reproducing various types of switching action under computer control. This electromechanical device exhibits a force versus displacement characteristic (possibly incorporating hysteresis) selected by the user on the PC. In this way, the suitability of a variety of switching actions for a patient can be assessed, and the optimal choice identified. Furthermore, for patients with very particular needs, this device can implement switching actions which are difficult or impossible to reproduce in a passive mechanical switch. For example, a patient may be able to close a thumb-operated switch but not be able to withdraw their thumb to open the switch again. Using the switch simulator, an exaggerated restorative force can be applied once the switch has been closed and until it returns to the fully open position.