speech and language therapist with more than 40 years of experience working with people who have special needs. She has a particular interest in Rett syndrome, and the general field of sensory and learning disabilities:
Since at least 2005, eye tracking has been used in conjunction with technology for access to communication systems for disabled persons: allowing the user to speak, send e-mail, browse the Internet, and perform other such activities, using only their eyes.
The most widely used current designs are video-based eye trackers. A camera focuses on one or both eyes and records their movement as the viewer looks at some kind of stimulus. Most modern eye-trackers use contrast to locate the center of the pupil and use infrared or near-infrared light to create a corneal reflection. The vector between these two features can be used to compute gaze intersection with a surface after a simple calibration for an individual – in other words, the computer can tell what the user is looking at. The new Tobii PCEye is an easy to use, stand-alone eye control device that can be used with most personal computers. It is quick to set up, highly accurate and provides total control of the computer using only the person’s eyes.
Director Global Services and Education Tobii Dynavox:
In 2001 Tobii began developing eyetracking systems for use in child development research. Analysis customers needed an eyetracker which allowed natural movement and did not require the person using the system to stay still. It was at this point that people with physical disabilities started to use Tobii eyegaze systems for communication. People with cerebral palsy and ALS now had a system which did not need complex calibration and difficult set up. Most of all, they could move naturally in front of the computer screen.
At this time, it was not envisaged that girls with Rett Syndrome would use eyegaze. Typically, someone with Rett Syndrome is ambulant and has hand movement. This led professionals looking for AAC solutions to focus on tablet computer based systems. However, the apraxia in girls with Rett Syndrome makes consistent functional hand use difficult to achieve. Eyegaze is a much more successful approach. It is a more natural interaction for someone with apraxia and gives the girls an access method they can rely on and trust themselves to succeed with. Nowadays, we have hundreds of girls accessing computers and AAC systems around the world, with varying success it must be said. As an AAC system, it still needs to be taught and parents and professionals must commit to consistent interaction methods. This also means that people like to trial a system first. However, the first barrier of access does seem to be overcome best with eyegaze systems.
More information http://www.tobii.com/en/assistive-technology/north-america/disabilities/common-disabilities/rett-syndrome/
special educator, speech and language therapist:
Every child has a right to communicate and we, as a society, are obligated to do everything to respect this right and to make communication possible. It’s a fundamental aspect during social and emotional development, education, work or simply daily life. It’s a fundamental aspect while forming family bonds, making friends, standing up for oneself. Every child wants to communicate and IS able to communicate. Each and every behavior is a message, a communicate. Just not always it is a verbal communication.
There are children that cannot communicate verbally. But this doesn’t mean they don’t have anything to say. When I meet a child with severe disability, a child who is not able to speak nor to control hand movements, I always get a feeling that there are so many words kept in a cage of disability. And I can’t wait to get to those words, to make communication possible – cause it is every time a life changing experience to see a child being understood for the first time. Eyetracking is sometimes the only way to set free those trapped words.
It is especially exceptional when it comes to the children with Rett syndrome. Girls are finally able to control computer cursor by eye movements, they don’t need to fight with their own body anymore. There is no pressure to make a precise hand movement in certain amount of time – a child can just look at the screen and…the communication begins. It begins with playing simple cause and effect games, with drawing, with choosing from two – three objects, and then, step by step, we are heading to messages and a real conversation. It is a very individual process but each time I have a privilege to observe a child during this journey with eyetracking, it’s clear how engage the child is, how skills develop during the process and also how tension fades away to give a space to joy of interactive play and communication. Thanks to eyetracking we can give a child a way to set free those trapped by disability words and to make communication effective.