Imagine if disabled people could control their wheelchairs by thought alone. Researchers at Duke Health in the US have come up with a brain-machine interface (BMI) that allows monkeys to do precisely that.
And in trials, the monkeys improved at operating the robotic wheelchair the longer they used it.
“Our data shows that the wheelchair is being assimilated by the monkey’s brain as an extension of its bodily representation of itself,” research leader Miguel Nicolelis told reporters.
“In essence the wheelchair is becoming a part of the monkey’s body.”
Overview of the experimental design (above): (A) The mobile robotic wheelchair was moved from one of the three starting locations (dashed circles) to a grape dispenser. The wireless recording system records the spiking activities from the monkey’s head device, and sends the activities to the wireless receiver to decode the wheelchair movement. (B) Schematic of the brain regions from which data was recorded velocity or steering. (C) Three video frames show one of the monkeys driving toward the grape dispenser. The right panel shows the average driving trajectories (dark blue) from the three different starting locations (green circle) to the grape dispenser (red circle). The light blue ellipses are the standard deviation of the trajectories.
Nicolelis and colleagues implanted two rhesus monkeys with multi-electrode arrays.
The animals were trained to navigate their wheelchairs and their brain activity was recorded as they did.
These recordings were used to translate brain signals into digital commands that could be used to control the wheelchair.
Nicolelis believes that the monkeys’ brain structures changed in response to training, which made them better and better at controlling the device over time.
The team’s previous work has been to develop BMIs that can control artificial limbs. Nicolelis says that the new development has a range of possibilities for paralysed people to control all sorts of devices around the home.
“We are not focused on the wheelchair – we’re actually developing robotic exoskeletons in parallel to this,” he told Gizmodo. “But in principle, it could be any kind of vehicle because this is a general purpose approach.”
With humans, it should be even easier to incorporate devices as an extensive of a person's mind.
"You can talk to the patient about what they can imagine and think about" to make the wheelchair move, Nicolelis told the LA Times.
The research was published in Scientific Reports.