A breakthrough that allows people to control a robotic arm using only their minds has been made by researchers at the University of Minnesota.

The research has the potential to help millions of people who are paralyzed or have neurodegenerative diseases.

The study is published online in Scientific Reports, a Nature research journal.

Research subjects fitted with a brain cap moved the robotic arm by imagining moving their own arms. Credit: University of MinnesotaResearch subjects fitted with a brain cap moved the robotic arm by imagining moving their own arms. Credit: University of MinnesotaThe study, led by Bin He, a University of Minnesota biomedical engineering professor, involves the noninvasive technique, called electroencephalography (EEG) based brain-computer interface. It records weak electrical activity of the subjects' brain through an EEG cap fitted with 64 electrodes and converts the "thoughts" into action by advanced signal processing and machine learning.

Eight healthy human subjects completed the experimental sessions wearing the EEG cap. Subjects gradually learned to imagine moving their own arms without actually moving them to control a robotic arm in 3D space.

The subjects started from learning to control a virtual cursor on a computer screen and then learned to control a robotic arm to reach and grasp objects in fixed locations on a table. Eventually, they were able to move the robotic arm to reach and grasp objects in random locations on a table and move objects from the table to a three-layer shelf by only thinking about these movements.

All eight subjects could control a robotic arm to pick up objects in fixed locations with an average success rate above 80% and move objects from the table onto the shelf with an average success rate above 70%.

The researchers say the brain-computer interface technology works due to the geography of the motor cortex—the area of the cerebrum that governs movement. When humans move, or think about a movement, neurons in the motor cortex produce electric currents.

Thinking about a different movement activates a new assortment of neurons, a phenomenon confirmed by cross-validation using functional MRI in a previous study. Sorting out these assortments using advanced signal processing laid the groundwork for the brain-computer interface used by the Minnesota researchers, He says.

He anticipates the next step of his research will be to further develop this brain-computer interface technology realizing a brain-controlled robotic prosthetic limb attached to a person's body or examine how this technology could work with someone who has had a stroke or is paralyzed.

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