Scheduled System Maintenance:
On Monday, April 27th, IEEE Xplore will undergo scheduled maintenance from 1:00 PM - 3:00 PM ET (17:00 - 19:00 UTC). No interruption in service is anticipated.
By Topic

Optimizing Assisted Communication Devices for Children With Motor Impairments Using a Model of Information Rate and Channel Capacity

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)
Sanger, T.D. ; Stanford Univ., Stanford ; Henderson, J.

For children who depend on devices to communicate, the rate of communication is a primary determinant of success. For children with motor impairments, the rate of communication may be limited by inability to contact buttons or cells rapidly or accurately. It is, therefore, essential to know how to adjust the device interface in order to maximize each child's rate of communication. The optimal rate of communication is determined by the channel capacity, which is the maximum value of the information rate for all possible keyboard button or cell layouts for the communication device. We construct a mathematical model for the information rate based on the relationship between movement time and the number of buttons per screen, the size of the buttons, and the length of a sequence of buttons that must be pressed to communicate each word in the vocabulary. We measure the parameters of the model using a custom-programmed touchscreen interface in 10 children with disorders of arm movement due to cerebral palsy who use a DynaVox communication device. We measure the same parameters in 20 healthy control subjects. We show that the model approximates the measured information rate and that the information rate is lower in children with motor impairments compared with control subjects. The theory predicts that for each child there is a combination of button size and number that maximizes the predicted information rate and thereby achieves communication at the optimal channel capacity. Programming communication devices with each child's predicted optimal parameters improved the communication rate in five of the ten children, compared with programming by professionals. Therefore, measurement of information rate may provide an assessment of the effect of motor disorders on success in assisted communication. Optimization of the information rate may be useful for programming assisted communication devices.

Published in:

Neural Systems and Rehabilitation Engineering, IEEE Transactions on  (Volume:15 ,  Issue: 3 )