Caption: Research subjects at the University of Minnesota fitted with a specialized noninvasive brain cap were able to move the robotic arm just by imagining moving their own arms.

For the first time ever researchers at the University of Minnesota developed a robotic arm that can be controlled through the mind.

Bin He, a University of Minnesota biomedical engineering professor and lead researcher on the study, explained this is a breakthrough that could help millions of people who are paralyzed or have neurodegenerative diseases.

“This is the first time in the world that people can operate a robotic arm to reach and grasp objects in a complex 3D environment using only their thoughts without a brain implant,” he said in a statement. “Just by imagining moving their arms, they were able to move the robotic arm.”

The arm is controlled using a noninvasive technique called electroencephalography (EEG), which is based on brain-computer interfaces. It records weak electrical activity of the subjects’ brain through a specialized, high-tech EEG cap fitted with 64 electrodes and converts the “thoughts” into action by advanced signal processing and machine learning.

The researchers tested the invention on eight healthy human subjects.

The participants gradually learned to imagine moving their own arm without actually moving them to control a robotic appendage in 3D space.

The subjects improved from initially being able to control a virtual cursor on a computer screen to being able to control a robotic arm to reach and grasp objects in fixed locations on a table to a three-layer shelf by only thinking about the movements.

Average success rates for the eight subjects in controlling the robotic arm and picking up objects in fixed locations was above 80 percent and the success rate in moving objects from the table onto the shelf was above 70 percent.

“This is exciting as all subjects accomplished the tasks using a completely non-invasive technique,” He said. “We see a big potential for this research to help people who are paralyzed or have neurodegenerative diseases to become more independent without a need for surgical implants.”

The brain-computer interface is able to work due to the geography of the motor cortex—the area of the cerebrum that governs movement.

Neurons in the motor cortex produce tiny electric currents when humans move or think about a movement. When a human thinks about a different movement it activates a new assortment of neurons, a phenomenon confirmed by cross-validation using functional MRI in He’s previous study.

According to He, sorting out these assortments using advanced signal processing laid the groundwork for the brain-computer interface used by University of Minnesota.

The robotic arm is seen as an advancement of his previous research.

“Three years ago, we weren’t sure moving a more complex robotic arm to grasp and move objects using this brain-computer interface technology could even be achieved,” He said. “We’re happily surprised that it worked with a high success rate and in a group of people.”

He said the next step would be to further develop the brain-computer interface technology realizing a brain-controlled robotic prosthetic limb attached to a person’s body or examine how the technology could work with someone who has had a stroke or is paralyzed.

In addition to He, who also serves as director of the University of Minnesota Institute for Engineering in Medicine, the research team includes biomedical engineering postdoctoral researcher Jianjun Meng (first author); biomedical engineering graduate student Bryan Baxter; Institute for Engineering in Medicine staff member Angeliki Bekyo; and biomedical engineering undergraduate students Shuying Zhang and Jaron Olsoe. The researchers are affiliated with the University of Minnesota College of Science and Engineering and the Medical School.

The study was published in Scientific Reports.