Three Austrian men have become the first in the world to undergo a new technique called "bionic reconstruction," enabling them to use a robotic prosthetic hand controlled by their mind, according to new research published in The Lancet.
All three men suffered for many years with brachial plexus injuries and poor hand function as a result of motor vehicle and climbing accidents. The new technique was developed by Professor 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 Neurorehabilitation Engineering of the University Medical Center Goettingen.
It 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 in activities of daily living.
"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," explains Professor Aszmann.
"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."
Before amputation, 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.