Researchers at the University of Maryland have developed an interface that offers the potential to improve the lives of millions of people. The interface, which can be worn like a cap, may someday allow people to use mental signals to control computers, prosthetic limbs, and motorized wheelchairs.

According to Associate Professor of Kinesiology Jose Contreras-Vidal, "We are on track to develop, test, and make available to the public, within the next few years, a safe, reliable, non-invasive brain computer interface that can bring life-changing technology to millions of people whose ability to move has been diminished due to paralysis, stroke, or other injury or illness."

The fact that it is non-invasive means that the sensors are fitted within the cap, instead of implanted in the skulls of the patients. The technology uses EEG to monitor the wearer's brain waves and translate them into movement commands for computers and other devices.

Contreras-Vidal and his team have published three major papers on their technology over the past 18 months. The most recent paper, which appeared in the Journal of Neurophysiology, describes how the team used EEG brain signals to reconstruct the movements of the ankle, knee, and hip joints when people walked on treadmills.

The researchers believe that the EEG signals can be used to study the cortical dynamics of walking and then develop brain-machine interfaces that would allow people to regain the ability to walk.

By decoding the brain activity involved in a normal walking motion, the team intends to use the EEG data to teach stroke victims to think in certain ways and match their own EEG signals with the normal signals. This could result in retraining healthy areas of the brain in what is known as neuroplasticity.

With grants from the National Science Foundation and the National Institutes of Health, the Maryland team is working on three intriguing projects:

1. With researchers at Rice University, the University of Michigan, and Drexel University, Contreras-Vidal and his colleagues are designing a prosthetic arm that amputees can control directly with their brains.

2. In another project, they are combining the brain cap's EEG-based technology with a DARPA-funded robotic arm designed by researchers at the Johns Hopkins Applied Physics Laboratory to function like a normal limb.

3. They are collaborating with New Zealand start-up Rexbionics, the developer of a powered lower-limb exoskeleton called Rex that could be used to restore the ability to walk in people with spinal cord injuries.