Jan Scheuermann, a quadriplegic woman, recently showed how skillfully a prosthetic arm can be used using only her mind. Paralyzed from the waist down over 13 years ago, Jan has lost movement of most of her body and suffers from spinocerebellar degeneration. She recently decided to undergo a procedure in Pittsburgh, Pennsylvania giving her use of a prosthetic arm to possibly give her back the ability to reach, grasp and manipulate.
Jan had two silicon-substrate microelectrode arrays implanted into her motor cortex, which recorded grouped neuronal activity. The activity from her brain was translated into electrical signals interpreted as intended movement commands for this mechanical extremity. After two days of training, Jan was able to move the prosthetic arm. After 13 weeks, she was able to perform three dimensional tasks using the prosthetic arm with a 92% success rate.
The action research arm test, an exam given to stroke victims to assess their returned arm function, was given to Jan periodically over the training period. Her score rose from 0 to 17 out of a possible 27. This well surpassed the needed 5.7 point gain to demonstrate clinical significance. Her three dimensional target reaching success rate rose to 92% during the final two weeks without computer assistance, which was well over the 6% chance success rate.
Over the course of 13 weeks, Jan was able to skillfully reach and manipulate objects with an extension of a body part that she hasn’t had control over in 13 years. With the development of such technology coming to life, war veterans, neurodegenerative disease sufferers, and the like may no longer fear the threat of losing a limb.
Jennifer L Collinger, Brian Wodlinger, John E Downey, Wei Wang, Elizabeth C Tyler-Kabara, Douglas J Weber, Angus JC McMorland, Meel Velliste, Michael L Boninger, Andrew B Schwartz. 2012. High-performance neuroprosthetic control by an individual with tetraplegia. The Lancet.