Video of the week: robotic arm controlled by thoughts

The research from the University of Minnesota has the potential to help those with paralysis or neurodegenerative diseases.

The study is published by Scientific Reports in a paper titled Noninvasive Electroencephalogram Based Control of a Robotic Arm for Reach and Grasp Tasks.

“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,” said Bin He, a University of Minnesota biomedical engineering professor and lead researcher on the study. “Just by imagining moving their arms, they were able to move the robotic arm.”

According to the University, the non-invasive technique, - electroencephalography (EEG) based brain-computer interface - records weak electrical activity of the subjects’ brain through a specialised EEG cap fitted with 64 electrodes and converts thoughts into action by advanced signal processing and machine learning.

Eight healthy human subjects are said to have completed the experimental sessions of the study wearing the EEG cap. Subjects gradually learned to imagine moving their own arms without moving them to control a robotic arm in 3D space. They started from learning to control a virtual cursor on 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 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 per cent and move objects from the table onto the shelf with an average success rate above 70 per cent.

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

The researchers said the brain-computer interface technology works due to the geography of the motor cortex, which is the area of the cerebrum that governs movement. When humans move, or think about a movement, neurons in the motor cortex produce tiny electric currents. Thinking about a different movement activates a new assortment of neurons, a phenomenon confirmed by cross-validation using functional MRI in He’s previous study. Sorting out these assortments using advanced signal processing laid the groundwork for the brain-computer interface used by the University of Minnesota researchers, He said.

The robotic arm research builds upon He’s research published three years ago in which subjects were able to fly a small quadcopter using the non-invasive EEG technology.

https://www.youtube.com/watch?v=lsraC04Mm8w

“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.”