A multiple camera tongue switch for a child with severe spastic quadriplegic cerebral palsy

Abstract

Purpose. The present study proposed a video-based access technology that facilitated a non-contact tongue protrusion access modality for a 7-year-old boy with severe spastic quadriplegic cerebral palsy (GMFCS level 5). The proposed system featured a centre camera and two peripheral cameras to extend coverage of the frontal face view of this user for longer durations.

Method. The child participated in a descriptive case study. The participant underwent 3 months of tongue protrusion training while the multiple camera tongue switch prototype was being prepared. Later, the participant was brought back for five experiment sessions where he worked on a single-switch picture matching activity, using the multiple camera tongue switch prototype in a controlled environment.

Results. The multiple camera tongue switch achieved an average sensitivity of 82% and specificity of 80%. In three of the experiment sessions, the peripheral cameras were associated with most of the true positive switch activations. These activations would have been missed by a centre-camera-only setup.

Conclusions. The study demonstrated proof-of-concept of a non-contact tongue access modality implemented by a video-based system involving three cameras and colour video processing.

Keywords:

• Physical access
• access technology
• assistive technology
• video processing
• paediatric rehabilitation

Acknowledgements

We would like to acknowledge support from Natural Science and Engineering Research Council of Canada (NSERC), Canada Research Chairs, and Bloorview Childrens Hospital Foundation. Also, we would like to thank our case study participant and his family for dedicating their time and effort participating in this research.