Three Austrian men have become the first in the world to undergo a pioneering new technique called “bionic reconstruction”. This cutting edge technology enabling them to use a robotic prosthetic hand controlled entirely by their mind.
The new technique was developed by Oskar Aszmann, director of the Christian Doppler Laboratory for Restoration of Extremity Function at the Medical University of Vienna, together with engineers from the department of neuro-rehabilitation engineering of the University Medical Centre, Goettingen.
The technique combines selective nerve and muscle transfers, elective amputation and replacement with an advanced robotic prosthesis (using sensors that respond to electrical impulses in the muscles). Following comprehensive rehabilitation, the technique restored a high level of function in all three recipients aiding and enhancing their of daily living activities.
All three men are now able to accomplish various everyday tasks such as picking up a ball, pouring water from a jug, using a key, cutting food with a knife or using two hands to undo buttons.
They suffered for many years with brachial plexus injuries and poor hand function as a result of motor vehicle and climbing accidents.
The brachial plexus is a network of nerves that originate in the neck region and branch off to form most of the other nerves that control movement and sensation in the upper limbs including the shoulder, arm, forearm and hand.
“In effect, brachial plexus avulsion injuries represent an inner amputation, irreversibly separating the hand from neural control. Existing surgical techniques for such injuries are crude and ineffective and result in poor hand function,” Aszmann 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,” he added.
All three patients spent an average of nine months undergoing cognitive training, firstly to activate the muscles and then to use the electrical signals to control a virtual hand. Once they had mastered the virtual environment, they practiced using a hybrid hand — a prosthetic hand attached to a splint-like device fixed to their non-functioning hand. Three months after amputation of their non-functional hands, robotic prostheses gave all three recipients substantially better functional movement in their hands as well as improved quality of life with less pain.
Brachial plexus injuries often occur as a result of trauma from high speed collisions, especially in motorcycle accidents, and in collision sports such as rugby and American Football.
Aszmann said, “So far, bionic reconstruction has only been done in our centre in Vienna. However, there are no technical or surgical limitations that would prevent this procedure from being done in centres with similar expertise and resources.”
Simon Kay who carried out the UK’s first hand transplant and Daniel Wilks from Leeds Teaching Hospitals NHS Trust said, “The present findings 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.
