A volunteer is shown here calibrating the brain control interface. (Photo credit: Korea University / TU Berlin)

A volunteer is shown here calibrating the brain control interface. (Photo credit: Korea University / TU Berlin)

A study published in the August 18 issue of Journal of Neural Engineering showcases how members of a team of researchers from two continents developed an interface that they suggest uses brain signals to control a lower-limb exoskeleton.

How it works

The device works like this: Using an electroencephalogram (EEG) cap placed on the head, the system allows the user to move forward, turn left and right, sit, and stand by staring at one of five flickering light-emitting diodes (LEDs), according to a media release from the Institute of Physics.

Each of the five LEDs flickers at a different frequency, and when the user focuses attention on a specific LED, this frequency is reflected within the EEG readout. This signal is identified and used to control the exoskeleton, the release continues.

Overcoming noise

A key problem has been separating these precise brain signals from those associated with other brain activity, and the highly artificial signals generated by the exoskeleton.

“Exoskeletons create lots of electrical ‘noise,’ ” explains Klaus Muller, one of the study’s authors. Scientists at TU Berlin in Germany and Korea University in Korea teamed for this effort, according to the Institute of Physics media release.

“The EEG signal gets buried under all this noise—but our system is able to separate not only the EEG signal, but the frequency of the flickering LED within this signal,” Muller continues.

Changing the outlook for ALS and SCI

Muller notes that this exoskeleton system has the potential to be used on people affected by illness or disability.

“People with amyotrophic lateral sclerosis (ALS) or high spinal cord injuries face difficulties communicating or using their limbs,” Muller continues in the release.

“Decoding what they intend from their brain signals could offer means to communicate and walk again.”

The control system could serve as a technically simple and feasible add-on to other devices, with EEG caps and hardware now emerging on the consumer market, according to the release.

The research team notes in the release that they are now working to reduce the “visual fatigue” associated with longer-term users of such systems.

“We were driven to assist disabled people, and our study shows that this brain control interface can easily and intuitively control an exoskeleton system—despite the highly challenging artifacts from the exoskeleton itself,” Muller concludes in the release.

[Source(s): Institute of Physics, EurekAlert]