Eye Gaze controlled devices

[blark]

Eye gaze controlled devices are intriguing. I understand how to evaluate a user if he/she has clearly established symbol use through partner-assisted scanning. We have some students with limited hand use, who also appear to be at an emerging communication level.  How would you set up an evaluation of eye gaze systems with these potential users?  I want to remain open, yet objective, in analyzing their communication behaviors.  Ideas?

[barbaralyn]

There are a couple aspects to this type of assessment.  First, the client must understand a shared referent and the ability to relate to pictures as you indicated with partner assisted scanning.  Another aspect is the motor/head/eye control.  Can the individual maintain eye contact for a given number of seconds.  An additional aspect is the visual perceptual issues of looking at a screen, discriminating the symbols, glare, 2 dimensionality of pictures, depth perception and the like.  In addition to this aspect, the user needs to understand that the act of keeping his/her eyes on the desired symbol is itself the signal, just as hitting the switch is a signal or vocalizing to get the partner to stop scanning on the desired item is a signal. 

The two devices I have tried out both recognize the location of the eyes in relation to the screen and will 'evaluate' the users ability to locate a symbol building from a small number on a display of larger 'keys' to moving the individual to a greater number of smaller 'keys' and checking for the time it takes to triangulate the users eye point as an aspect of 'accuracy' and display, as well as key, size. 

In all honesty the best way to assess this particular access method is to get the vendor there with a device for the individual to try.  If they are at a very early emerging communication level, then you will need to make sure that the individual really understands that looking at the item for the given amount of time is actually activating the selection.  The individual does not necessarily need to understand this by explanation but does need to 'realize' the idea that the act of maintaining brief eye contact with the desired symbol is the same as activating a switch or vocalizing to stop the partner's scan for partner assisted scanning. 

Ultimately, I feel like this is an access method and device that needs to be experienced by the potential user.  Difficulties with the demonstration/trial then can be analyzed to determine if the struggle is a result of cognitive issues, symbol recognition, understanding of the maintaining eye contact, or other visual-perceptual issues.   

The ones I have tried are MyTobii and the EyeMax by Dynavox. 

Barbaralyn Harden, M.S., C.C.C.-Slp
Assistive Technology Specialist/Speech-Language Pathologist