On the tip of the tongue: learning typing and pointing with an intra-oral computer interface

Abstract

Purpose: To evaluate typing and pointing performance and improvement over time of four able-bodied participants using an intra-oral tongue-computer interface for computer control. Background: A physically disabled individual may lack the ability to efficiently control standard computer input devices. There have been several efforts to produce and evaluate interfaces that provide individuals with physical disabilities the possibility to control personal computers. Method: Training with the intra-oral tongue-computer interface was performed by playing games over 18 sessions. Skill improvement was measured through typing and pointing exercises at the end of each training session. Results: Typing throughput improved from averages of 2.36 to 5.43 correct words per minute. Pointing throughput improved from averages of 0.47 to 0.85 bits/s. Target tracking performance, measured as relative time on target, improved from averages of 36% to 47%. Path following throughput improved from averages of 0.31 to 0.83 bits/s and decreased to 0.53 bits/s with more difficult tasks. Conclusions: Learning curves support the notion that the tongue can rapidly learn novel motor tasks. Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, which makes the tongue a feasible input organ for computer control.

Implications for Rehabilitation

• Intra-oral computer interfaces could provide individuals with severe upper-limb mobility impairments the opportunity to control computers and automatic equipment.

• Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, but does not cause fatigue easily and might be invisible to other people, which is highly prioritized by assistive device users.

• Combination of visual and auditory feedback is vital for a good performance of an intra-oral computer interface and helps to reduce involuntary or erroneous activations.

• Assistive technology
• computer input
• computer interface
• learning
• performance
• throughput
• usability

Acknowledgements

The authors would like to acknowledge the technical support provided by Henrik Vie Christensen, PhD and Eugen R. Lontis, PhD in the production of the ITCI for the tongue selectivity experiments. They also thank Bo Bentsen, PhD and Leif Alenmyr, DDS for the dentistry support and production of the palatal models. Special thanks to John Scott for the Whack-A-Mole source code on which the game used for this study was based, and to Eatoni Ergonomics for providing an API to use LetterWise for character disambiguation.