AUSTRIA – Three Austrian amputees that suffered injuries to the brachial plexus – a critical mass of nerves linking the arm and shoulder to the spine and brain, have been able to move their fingers, pick and use objects and also do common everyday tasks by just mind-controlling the bionic reconstruction prostheses fixed to their hands.
Published in the British medical journal The Lancet, the report suggests the three men were now able to use their bionic hands by just controlling it through their own thoughts.
“In effect, brachial plexus avulsion injuries represent an inner amputation, irreversibly separating the hand from neural control,” said Professor Oskar Aszmann, Director of the Christian Doppler Laboratory for Restoration of Extremity Function at the Medical University of Vienna, who pioneered the technique.
“Existing surgical techniques for such injuries are crude and ineffective and result in poor hand function,” he said. “The scientific advance here was that we were able to create and extract new neural signals via nerve transfers amplified by muscle transplantation. These signals were then decoded and translated into solid mechatronic hand function.”
The lower arms of the amputees were amputated again and then fitted with a robotic arm that responds to electrical impulses. The three participants underwent cognitive training for nine months before the lower arm amputation was done – they were taught to activate their muscles and then learned to manage electric signals to move their bionic hands. Then they learned using the prostheses attached to their arms; but doctors waited three months for the wounds to heal before fixing them with the prosthesis.
“So far, bionic reconstruction has only been done in our centre in Vienna,” said Professor Aszmann. “However, there are no technical or surgical limitations that would prevent this procedure from being done in centers with similar expertise and resources.”
However, Professor Simon Kay who did the UK’s first hand transplant, and Daniel Wilks from Leeds Teaching Hospitals NHS Trust, Leeds, UK said, “The present findings—and others—are encouraging, because this approach provides additional neural inputs into prosthetic systems that otherwise would not exist.
“However, the final verdict will depend on long-term outcomes, which should include assessment of in what circumstances and for what proportion of their day patients wear and use their prostheses,” and then they added: “Compliance declines with time for all prostheses, and motorized prostheses are heavy, need power, and are often noisy, as well as demanding skilled repair when damaged.”