Dissecting frogs, with feeling

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By Barry Shell

That could all change as Vafai (right) perfects a virtual-frog dissection system for schools as part of her engineering science master's thesis. The system includes software she developed for a computer mouse-like scalpel, called a Phantom, that gives sensory feedback as students make incisions. The device not only detects motion but also gives force feedback by resisting the user's hand movements.

"This is the first haptic frog dissection system in the world," says Vafai, using a term derived from the Greek word for touch. The human haptic sensory system develops in the fetus before any of the other senses. Touch is our most primitive sensation.

One of Vafai's challenges was to make the software fast enough that users would not perceive a lag between making a cut and feeling it in their fingers. "The knife cuts differently and gives different sensations depending on how you hold it, how you move it and what you are cutting," says engineering science professor Shahram Payandeh, Vafai's supervisor.

Vafai's research won the best demo award in June 2006 at a Precarn Institute of Robotics and Intelligent Systems conference. Precarn (the Pre-Competitive Applied Research Network), which partially funded the frog research, is a consortium of more than 300 Canadian high-tech corporations that supports the pre-commercial development of leading edge technologies.