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Efficient Tongue-Computer Interfacing for People with Upper-Limb Impairments

Author: Héctor A. Caltenco, Dept. of Health Science and Technology, Aalborg University


e-ISBN: 9788792329943

Price: Notify Me

Available: December 2011
Downloads: [1842]

Downloads: [1842]  
Technical | Layman

Layman Description:

Efficient tongue-computer interfacing for people with upper limb impairments An efficient interface between a user and a computer system that ensures a correct degree of control and a correct interpretation of the user's wishes is vital for the interaction between humans and computers. Because the mobility of people with tetraplegia is scarce, they may not have the ability to efficiently control a computer via a keyboard or mouse. They may need a computer interface requiring a minimum number of movements. Therefore computer interface designers often minimize the number of keys or functions available for use. In many cases this leads to single-switch interfaces, in which the user can only press one button, resulting in slow and tedious interaction. However, a fair amount of operations can still be allowed in computer interfaces for some people that still have complete mobility and control of tongue and eyes, in case of individuals with spinal cord injury. The objectives of this Ph.D. research are to research methods for designing an accurate and efficient inductive tongue-computer interface (ITCI), which ensures a sufficient degree of control and a correct interpretation of the user's wishes. In order to design efficient tongue-computer interfacing methods for people with movement disabilities, several studies were performed.

In the first study, an internet survey collected potential users' opinions of their current computer interfaces. Also their desirable applications for future independent control of assistive devices were assessed. The study provided valuable insight on what should be done and what should be avoided when designing computer interfaces, as well as helped to prioritize alternative applications to interfaced by the ITCI. In the second study, tongue-selectivity experiments were used to evaluate how fast and accurate different areas in the mouth can be selected with the tip of the tongue. The results helped to determine the appropriate number and the optimal location of sensors inside the mouth. The third study evaluated functionality of the ITCI as a keyboard and mouse replacement. "Typing" and "pointing" exercises were performed over three consecutive training sessions. From this study, it was clear that it was necessary to improve the accuracy of typing with the ITCI. Therefore a fourth study evaluated three different feedback types that improve the accuracy of typing: visual feedback, tactile feedback and mouse-pointer feedback (using an on-screen keyboard). Visual feedback was selected as the default typing feedback method for further studies and further development of the ITCI. The fifth and final study evaluated typing and pointing performance of the ITCI over an 18-session training regime dispersed over a period of two months. This study was also used as an iterative design process of tongue-computer interface software that extends the functionality of the ITCI. The software provides visual and auditory feedback for sensor selection and command acknowledgement. It also provides the text prediction capabilities that improves typing speeds.

In summary, results from the studies showed that the ITCI is a feasible way for people with severe upper-limb impairments to control a personal computer. Tongue-computer interfacing show promising results as a replacement of mouse and keyboard for individuals with severe physical disabilities. Motor learning evidence support the notion that the tongue can rapidly learn tongue movements required for computer control, and the viability of using the tongue to control personal computers.


Keywords:

Adaptive Neuro-Fuzzy Inference Systemtarget Activation Time Activation UnitConfidence Interval