A Bristol-based roboticist has developed a robotic prosthetic hand using 3D-printed components that costs as little as £650, which is much cheaper than existing technology.
Joel Gibbard first came up with the idea for the Dextrus robotic hand while studying Robotics at the University of Plymouth in 2011.
He developed a prototype for his final-year project, before leaving university to take up a job as an engineer at National Instruments.
After two years in the workplace, he left his job in March 2013 to launch the Open Hand Project, an open-source venture that aims to make robotic prosthetic hands accessible for people in the developing world.
Currently one of the leading alternatives -- I-Limb -- can cost anywhere between £25,000 and £80,000.
Gibbard's hand uses off-the-shelf DC motors with a spool on the end that connects to a steel "tendon" that can be tightened and loosened when the user wants to move their fingers. 3D-printed plastic parts work like bones and a rubber coating acts as the skin.
"Each finger is individually actuated so you can grasp funny shaped objects. It's not all that complicated. I've put a little tensioner in between each one so you have a bit of mechanical compliance," Gibbard told Wired.co.uk.
The user can control the fingers using electomyographical signals picked up from the muscle in their arm using stick-on electrodes. "Even if an amputee has lost their hand, all of the muscles are still in the forearm and they can still flex them, so you can use that signal," Gibbard explains.
Users have to use a bit of trial and error to find the optimum positions for the electrodes, but Gibbard plans to make software account for the deviations between patients.
Gibbard doesn't know the scale of the market for hand amputees, but he told us that a prosthetist he spoke to in Bristol works with around 100 hand amputees. "I don't see the amputee market being huge, but there could be a decent market with research institutions for people working in robotics," he said.
He's already tested the prosthesis on a chef called Liam Corbett, who lost his hand to meningitis two years ago and contacted Gibbard via Facebook when he heard about the Open Hand Project. "He's very impressed," said Gibbard.
In a video on the project's Indiegogo page, Corbett says: "I think it's certainly going to enable me to do the finer things in life which I certainly haven't been able to do with a hook... I would be proud to wear this, it would make me feel more confident."
The biggest challenge so far has been electrical noise. "When I've been testing the hand in my room I've got a computer, two monitors, a 3D printer and speakers -- the more devices you have the more electrical noise is generated, so you have to filter that out. Even the electronics controlling the hand and the motors generate their own noise, so it has to be shielded from itself," he said.
You can donate money to the project through Indiegogo. Gibbard is hoping to raise £39,000 to refine the design of the hand and prototype the rest of the electronics.
"I'm not really trying to make money out of it; I just want to help people," Gibbard says.
This article was originally published by WIRED UK
