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

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 physic...