Bypassing the usual processes which require the user to see the object, physically stimulate the muscles in their arm to trigger a movement in the prosthetic limb, this hand ‘sees’ and reacts in one fluid movement.
A small number of amputees have already trialled the new technology and now the Newcastle University team are working with experts at Newcastle upon Tyne Hospitals NHS Foundation Trust to offer the ‘hands with eyes’ to patients at Newcastle’s Freeman Hospital.
“Responsiveness has been one of the main barriers to artificial limbs. For many amputees, the reference point is their healthy arm or leg so prosthetics seem slow and cumbersome in comparison,” explained Dr Kianoush Nazarpour, a senior lecturer in Biomedical Engineering at Newcastle University. “Now, for the first time in a century, we have developed an ‘intuitive’ hand that can react without thinking.”
Grouping objects by size, shape and orientation, according to the type of grasp that would be needed to pick them up, the team programmed the hand to perform four different ‘grasps’: palm wrist neutral (such as when you pick up a cup); palm wrist pronated (such as picking up the TV remote); tripod (thumb and two fingers) and pinch (thumb and first finger).
Using a camera fitted to the prosthesis, the hand ‘sees’ the object, picks the most appropriate grasp and sends a signal to the hand – all within a matter of milliseconds and ten times faster than any other limb currently on the market.
Dr Nazarpour said: “The beauty of this system is that it’s much more flexible and the hand is able to pick up novel objects – which is crucial since in everyday life people effortlessly pick up a variety of objects that they have never seen before.”
The work is part of a larger research project to develop a bionic hand that can sense pressure and temperature and transmit the information back to the brain.