Bionic Hand System Created By SFU Team Allows Parathlete To 'Move' Fingers

BURNABY, B.C. — Danny Letain never imagined he'd be able to "feel" his fingers move again after losing part of his arm in a workplace accident 35 years ago.

 

But with a new control system for a bionic hand developed by researchers at Simon Fraser University, he's now able to use the remaining muscles in his arm to activate the robotic limb.

 

The Paralympic skier said he feels as though his own hand is actually opening and closing, and he hopes eventually the futuristic-looking device can be developed for daily use.

 

"This one is way, way different, more exciting, because you're actually moving the fingers in that hand as if it was there," he said. "I'm actually working my fingers (using) my stump, which I've really never done before."

 

Letain and the research team, dubbed M.A.S.S. Impact or Mass Activity Sensor Strip, demonstrated the new control system at the university's Burnaby, B.C., campus on Tuesday.

 

The system consists of an armband of pressure sensors, which track movements in Letain's remaining muscles as he performs intuitive actions such as grabbing a ball. Computer algorithms then map the data from the sensors to move the bionic hand.

 

After several minutes of "training" the hand to do different actions, Letain picked up objects on a table, such as a tennis ball and a screw, with only a few fumbles that he chalked up to nerves.

 

The team is still perfecting the device ahead of the inaugural Cybathlon, or "Cyborg Olympics," in Switzerland in October. Letain will be the only Canadian competing in an obstacle course for people with powered-arm prostheses to perform tasks such as slicing bread and opening jars.

 

The aim is to spur innovations and test out different devices, but Letain's competitive side kicks in when he talks about the event.

 

"My plan to compete is keep my cool, but when it comes down to it and I have to get down to business, it'll be a real fast sprint to the finish," he said grinning. "I always say, 'Let's go, Canada!'"

 

M.A.S.S. leader Lukas-Karim Merhi said his team's new control system, the "brains" of the bionic hand, differs from other systems in that it's more intuitive.

 

Other robotic prostheses typically require users to learn how to isolate specific muscles in the arm to power the fingers. The SFU team's design allows people to use their muscles naturally, as they always have, to move the bionic hand.

 

"Open your hand right now. That's what he has to do," Merhi said. "Our sensors that are in the socket will recognize that pressure map for that specific grip pattern, and then tell the hand to move that way."

 

Letain lost his left arm below the elbow while working as a locomotive engineer in Castlegar, B.C., in 1980. He was on the side of a boxcar when he got knocked off and was dragged for 11 metres.

 

Since then he has used a standard hook prosthesis, which runs on elbow and shoulder movement and offers only a limited motion range. He said he's thrilled by the possibilities of the new device.

 

"I think it's just amazing that we're here doing this today," he said. "I feel totally privileged to be able to be a part of this, truly."