It uses electrical signals to stimulate movement in arm muscles where function has been lost, making it possible to work an arm-exercise machine - similar to an exercise bike but worked by the arms.
This enables people with paralysis to enjoy the health benefits of regular work-outs. For those with some function in their arms, it also helps them become strong enough to perform more activities unaided (wheelchair propulsion, moving from wheelchair to bed/bath, washing and eating etc). Aimed at people with injuries to the spinal cord, the system may be able to help those with paralysis caused by strokes or head injuries too.
This breakthrough is the result of a collaborative project undertaken by University of Glasgow engineers and Glasgow's Queen Elizabeth National Spinal Injuries Unit with funding from the Engineering and Physical Sciences Research Council (EPSRC).
Using electrodes placed on the skin, small pulses of electricity are delivered to the nerves serving the biceps and triceps, replacing signals from the brain that can no longer reach the nerves. Controlled from a computer, the signals' timing and strength can be adjusted to suit individual needs, e.g. when signs of muscle fatigue become apparent. The arm-exercise machine is linked into the computer system, enabling the effort needed to turn the machine to be adjusted.
Tetraplegic Sean Roake was one of the volunteers who worked with the project team during the research. His training programme, which consisted of three 20-30 minute sessions per week for several months, resulted in a 450% increase in muscle strength and a 50% increase in cardiopulmonary fitness. He says: "Everyday activities such as wheelchair-to-car transfers are so much easier now. I feel extremely positive knowing that I've taken responsibility for improving my health by exercising regularly using this system".
MEDICA.de; Source: Engineering and Physical Sciences Research Council