By BizLED Bureau
August 24, 2015: Researchers of Korea University (KU) and Technische Universität Berlin (TU Berlin) have developed a brain-computer interface that would allow quadriplegics to control a lower limb exoskeleton by looking at some flashing LEDs.
Lower limb exoskeletons help those who have lost the use of their legs and cannot walk. As a result, hand control on such a device is therefore essential. As a solution to this problem, scientists have created a hands-free brain-to-computer interface to control a lower limb exoskeleton by specifically decoding signals from the wearer?s brain. This has been possible by some flashing LEDs.
To operate the KU/TU Berlin unit, the user initiates commands by staring at one of the five flashing LEDs and an electroencephalogram (EEG) cap reads signals from the wearer?s brain corresponding to the desired mode of movement. As each LED flashes at a specific frequency, focusing on a particular one produces a specific signal in the user?s brain. The system is then able to interpret the readings of these signals via the EEG cap and convert them into system instructions to operate the exoskeleton.
The researchers claim their system also offers a much better signal-to-noise ratio by separating brain control signals from the surrounding noise of ordinary brain signals for more accurate exoskeleton operation than more conventional hard-wired systems.
“Exoskeletons create lots of electrical ‘noise’,” said Professor Klaus Muller, of the TU Berlin Machine Learning Group. “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. People with amyotrophic lateral sclerosis (ALS) [motor neuron disease or Lou Gehrig’s disease], or high spinal cord injuries face difficulties communicating or using their limbs. Decoding what they intend from their brain signals could offer means to communicate and walk again.”
The only downsides they noted were that participants suffering from epilepsy were excluded due to their possible reaction to the flashing LEDs, and operators suffered some degree of “visual fatigue” after long-term use.
The team’s paper is published in the Journal of Neural Engineering.
Source: Institute of Physics