Student designs eye-driven mouse for paraplegics
When a neurosurgery student was shot in the back in an attempted hijacking in July last year, it was not immediately apparent that his being rendered paraplegic would benefit others in a similar position.
His tragedy caused a chain of events which now has the University of Stellenbosch’s Engineering Faculty developing an eye-driven mouse which could allow the disabled to use computers and communicate more effectively, at affordable prices.
Dr Ebrahim Hansa (31) later died from his injuries, but not before his elder brother, Dr Cassim Hansa, had established through an internet search to find way of enabling him to communicate.
“There are ways, but they cost the absolute earth,” says Hansa, who is specialising as a physician.
Hansa met Thailia Cronje of the University of Stellenbosch’s Health Sciences faculty when she took some flowers to his brother at Groote Schuur Hospital and asked her if the university could help.
Cronje took up the cause, turning to the Engineering Faculty where she got hold of Dr Mike Blankenberg, of the electronic engineering department. Blankenberg in turn offered the challenge to Alette Barry, a fourth-year student.
Barry was immediately excited by the proposed project.
“It was at the time that we were handing in our proposals for our final projects and I had already handed in a biomedical-type idea.
I wanted to do a heart monitor.
Dr Blankenberg offered it to me as another option and I thought it would be very interesting,” she said.
Barry’s design, although not finalised, allows a paraplegic to use normal computer software to communicate, unlike the more expensive types currently on offer.
Cassim Hansa had found that computers which would help his brother communicate would cost a prohibitive R140 000 to R280 000, while Barry’s design could cost a mere R500 on top of the initial outlay on hard and software.
“It can run on any computer ...all-in-all it will cost about R2 500 to put together a good system, I’d think,” he says.
What Barry designed is, basically, an eye-driven mouse.
“It’s completely different (to the designs now available) it tracks eye movement and gives the computer the same signals as the mouse,” she said.
For Dr Cassim Hansa it’s the freedom it gives a patient that is important.
“It gives the person that much more control of their own environment. They can turn off lights, watch programmes on TV, surf the ‘net, ring bells and attract people’s attention. It’s just the (design’s) interface which is a problem.?
Barry’s system works on a pair of glasses which have sensors that capture and transform signals from the eyes.
Barry explains that there are “blinking sensors” that work on the amount of infrared light reflected back into the sensor when the user opens and closes his eye, and “tilting sensors”. The tilting sensors work on the tilt of the head and were what she initially thought would be easiest.
“But a lot of paraplegics are in traction and can’t tilt their heads, so we have both (sensors).”
For Barry, who has now moved to Gauteng and works at an avionics firm, the project was challenging and exciting.
“I really enjoyed the interaction between person and machinery. A computer works on numbers, it’s wrong or right, but with people there are so many variables,” she says.
Barry says she was sorry to bid the unfinished project goodbye.
“The most difficult part is making it into a saleable product ...I would have liked to finish it, but you need a big lab, all the infrastructure, like at a university, and that is difficult for someone like me, fresh out of university.”
The university has not given up on putting the finishing touches to the project, however.
Blankenberg explains that what Barry’s design has on others is its aim at affordability. To make it more affordable the university is attempting to extend its physical adaptability.
“We have had a few inquiries ...we are waiting for input from potential users as to what physical input would be suitable, some would rather use a foot.
“The adaptive side is always difficult, the electronic side is easy. The main thing is to make it available at a reasonable price.”
Blankenberg says the university wants to develop a range of “input devices” which can be mixed and matched because if the device is adapted to each individual, that would be very expensive. - Sapa