Neuroprosthetic hand provides tactile feedback | The Engineer
Engineers in the US and China have designed a neuroprosthetic hand that provides tactile feedback and a degree of primitive sensation in a volunteer’s residual limb.
The soft, lightweight, and potentially low-cost neuroprosthetic hand is the result of a collaboration between engineers at MIT and Shanghai Jiao Tong University.
“This is not a product yet, but the performance is already similar or superior to existing neuroprosthetics, which we’re excited about,” said Xuanhe Zhao, professor of mechanical engineering and of civil and environmental engineering at MIT. “There’s huge potential to make this soft prosthetic very low cost, for low-income families who have suffered from amputation.”
Zhao and his colleagues have published their work in Nature Biomedical Engineering.
The team’s artificial hand – made from the commercial elastomer EcoFlex – comprises five balloon-like fingers embedded with segments of fibre, similar to articulated bones in actual fingers. The digits are connected to a 3D-printed ‘palm,’ shaped like a human hand.
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Rather than controlling each finger using mounted electrical motors the researchers used a pneumatic system to inflate fingers and bend them in specific positions. This system, including a small pump and valves, can be worn at the waist.
According to MIT, Lin developed a computer model to relate a finger’s desired position to the corresponding pressure a pump would have to apply to achieve that position. Using this model, the team developed a controller that directs the pneumatic system to inflate the fingers, in positions that mimic five common grasps.
The pneumatic system receives signals from electromyography sensors that measure electrical signals generated by motor neurons to control muscles. The sensors are fitted at the prosthetic’s opening, where it attaches to a user’s limb. In this arrangement, the sensors can pick up signals from a residual limb, such as when an amputee imagines making a fist.