When Bloorview engineering student Negar Memarian first met Dung, he wanted a way to select “A, B, C, or D” so he could answer multiple choice tests on his own. As a business college student, he didn’t like his mother interpreting his answers for him.
“This guy had so much motor disability and so much intelligence,” Negar recalls.
During their meeting, she noticed that while Dung’s movement in general was limited, he could open and close his mouth.
Knowing that an infrared camera detects heat – and our oral cavity is warm – Negar developed a system that translates a camera image of Dung’s open mouth into a computer command, allowing him to type, play simple computer games, and turn pages in an online book.
Not surprisingly, the first word he typed – by opening his mouth to select the letters he wanted when an on-screen keyboard scanned the alphabet – was a tribute to Yen: M U T H E R (mother).
Infrared cameras – used for military surveillance, medical imaging and firefighting – map cold regions with dark colours and warm areas with brighter ones. Extreme warmth is represented with white.
Negar created an algorithm that activates a switch when it detects movement and the shape of Dung’s open mouth. He tends to smile, resulting in a horizontal patch of heat-induced white. An open mouth is like an on switch, while the closed mouth signals off.
The current high-end infrared system Dung uses at Bloorview costs about $50,000 and isn’t portable. Negar and her colleagues hope to develop a handheld version that can be mounted on a rod on Dung’s wheelchair, to the side of his head, at a cost of about $2,000.
The advantages of the thermal camera are that it works regardless of light conditions and is non-invasive.
Negar is completing her biomedical engineering PhD at the University of Toronto and her research training in Tom Chau’s lab at Bloorview. Tom holds the Canada Research Chair in pediatric rehab engineering.
Negar began her studies in electrical engineering, but says she quickly tired of it. “All of these equations and numbers were very interesting, but I couldn’t understand how to apply them for the benefit of people. Biomedical engineering is the way to make a contribution directly to people.”