With the advancement in medical science and technology, prosthetics have come a long way from stiff robotic arms to flexible components and researchers are always trying different methods to make them more user-friendly. Nowadays, neuroprosthetics are getting more and more common which are bionic limbs designed to sense the user’s residual muscle signals and try to mimic their motions as accurately as possible. These devices are built using electrical motors around metal skeletons which make them heavy and uncomfortable to use. Not only that but they can cost thousands of dollars so not everyone has access to them.
To overcome this problem, engineers at MIT and Shanghai Jiao Tong University have designed a low-cost neuroprosthetic hand that is soft and lightweight. Amputees tested the artificial limb by performing daily activities such as pouring juice in a glass, petting a cat, and zipping a suitcase and concluded that it worked better than those rigid neuroprosthetics and was surprisingly quite durable as well. It is also worthy to note that the total cost of the components used amount to a total of $500, which is half the price of neuroprosthetics available in the market right now. “This is not a product yet, but the performance is already similar or superior to existing neuroprosthetics, which we’re excited about,” says Xuanhe Zhao, professor of mechanical, civil, and environmental engineering at MIT.
The smart arm is made with a soft, stretchy material called EcoFlex which makes it look quite similar to the robot’s hand from ‘Big Hero 6’! The arm comprises five balloon-like fingers, embedded with fiber segments which are then connected to a 3D printed hand. The arm uses a pneumatic system to accurately inflate the fingers and bend them in specific positions rather than controlling the whole finger together. The researchers also added a tactile feedback system which makes it different from the commercial neuroprosthetics. They stitched a pressure sensor to each fingertip which is wired to a specific location on the amputee’s residual limb so whenever it is pressed, it produces an electrical signal which the user can ‘feel’, giving them the sensation of touch. While the smart arm is not available for commercial use yet, Zhao and his team are hopeful that this low-cost prosthetic arm would have a huge potential for low-income families who have suffered from amputation.