Two biomedical engineering students have developed a prosthetic arm that is controlled by brain signals. The relatively inexpensive prosthetic limb is called Artificial Muscle-Operated (AMO) Arm and it allows amputees to avoid invasive surgeries. The AMO Arm is powered by ‘artificial muscles’ – simple pneumatic pumps and valves – to create movements so it does not rely on electrical and mechanical components. The arm is said to be controlled by the user’s brain signals via a brain-reading headset – although again, no word on which helmet the project uses to measure brainwaves.Developed by third-year student Thiago Caires and second-year student Michal Prywata, the AMO Arm is controlled by the brain and uses compressed air as the main source of power. Users wear a brain-computer interface headset which sends signals from the brain wirelessly to a miniature computer in the arm. The resulting information is sent to the pneumatic system, which in turn, activates the arm to create the correct movement. Simulating the expansion and contraction of real muscles, the system makes use of compressed air from a small, refillable tank in the user’s pocket. The artificial muscle system created by Caires and Prywata is a first in the field of prosthetics and they continue to work on perfecting their system. For example, the pair is working on a design to fit the tank into the arm itself.
“In just ten minutes of practising, a person can pick up the mind-control aspect of the technology,” says Prywata.
The initial concept for the AMO Arm was developed shortly after Caires and Prywata met at an Engineering open house in fall 2009. Each showcased different projects and were impressed with the other’s work. It took a year to develop the software program for the AMO Arm while the actual prototype was created during a marathon 72-hour design session.
Caires and Prywata’s invention went on to win first prize at the 2011 Ryerson Engineering Competition, and took home first-place awards for innovative design and social awareness at the Ontario Engineering Competition in February. The wins at the provincial level qualified Caires and Prywata for the Canadian Engineering Competition, where the AMO Arm placed second in the innovative design category.
Caires and Prywata are working to move each finger on the AMO Arm individually. “Independent finger movements require many more sensors,” Caires says. “For example, while not impossible, it’s still quite difficult to grab a key and unlock a door.”
In the future, the pair would also like the AMO Arm to sense different materials (e.g., an egg versus a full bottle of water) and adjust the force used proportionately. They have already developed an innovative concept for capacitive sensing which detects different materials prior to contact. The students also have plans to develop an adaptive system, one that will progressively “learn” from a user’s movements and carry them out seamlessly.
Although they are still students, Prywata and Caires have formed their own company, Bionik Laboratories Inc., and are currently seeking three patents for the AMO Arm and their other technologies.