A lower-limb exoskeleton controlled by brain impulses has been developed by an international team of researchers, hoping to help disabled and ill individuals in the future.
The system consists of an EEG cap, a robotic leg exoskeleton and a set of five flickering diodes. The tested subject stares at the diodes, which triggers a response in his brain. The cap interprets which of the five diodes the user is staring at, corresponding to five types of action – moving forward, turning left or right, sitting and standing.
The system was developed by a team from Korea and Germany and described in the latest issue of the Journal of Neural Engineering.
The major challenge, the researchers said, was to separate the 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. “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.”
The team envisions the system could eventually help people suffering from ailments such as motor neurone disease or spinal cord injuries in which the person loses control over their body.
“Decoding what they intend from their brain signals could offer means to communicate and walk again,” Muller said.
If commercialised, the system would work together with other brain signal driven devices that are currently entering the consumer market.
During the trials, volunteers were able to learn how to operate the system in only a few minutes. The researchers are now working to reduce the ‘visual fatigue’ associated with longer-term use of such systems.