Client-centred development of an infrared thermal access switch for a young adult with severe spastic quadriplegic cerebral palsy

Abstract

Purpose. This study reports a client-centred development of a non-contact access switch based on an infrared thermal imaging of mouth opening–closing activity of an individual with severe spastic quadriplegic cerebral palsy.

Method. Over a 6-month period, the client participated in five test sessions to inform the development of an infrared thermal switch. The client completed eight stimulus-response trials (switch test) and eight word-matching trials (scan test) using the infrared thermal switch and provided subjective feedback throughout.

Results. For the switch test, the client achieved an average correct activation rate of 90% and average response time of 2.4 s. His mean correct activation rate on the scan test improved from 65 to 80% over the course of system development, with an average response time of 11.7 s.

Conclusions. An infrared thermography switch tuned to a client's extant orofacial gestures is a practical non-invasive access solution and warrants further research in clients with severe physical disability.

Keywords:

• Client-centred design
• severe motor disabilities
• assistive technology
• rehabilitation engineering

Acknowledgements

We thank the client and his mother for their enthusiasm and cooperation in this study. We acknowledge Mr. Pierre Duez and Mr. Ka Lun Tam for their assistance with the software and hardware aspects of the project. Also, we acknowledge Natural Sciences and Engineering Research Council of Canada, the Canada Research Chairs Programme, IBM Canada and Ontario Centres of Excellence for their financial support of this study.