A team of neuroscientists in the US have been carrying out clinical trials known as BrainGate. They’ve been working on a robotic arm for people who are unable to move their limbs so they can use and grasp objects using only the power of their minds.
Science journal Nature yesterday reported on this breakthrough. The team, made up of of neurologists, neuroscientists, engineers, computer scientists, neurosurgeons and mathematicians, carried out clinical trials with two study participants who had strokes that damaged their brain stems and left them with tetraplegia and unable to speak.
The scientists carried out a pilot clinical study of their BrainGate2 Neural Interface System on the two study participants known as Bob and Cathy.
The aim of the trials, the researchers said, was to obtain preliminary device safety information and to demonstrate the feasibility of people with tetraplegia using the system to perform three-dimensional reach and grasp movements.
Reading electrical impulses
The scientists implanted up to 100 hair-thin electrodes into the motor cortex of the study participants’ brains. The BrainGate technology reads electrical impulses from the brain and the computer translates signals into actions.
The aim was to decode signals from motor cortex neurons and then convert those signals to digital commands the robotic device could follow to carry out movements.
"We have previously shown that people with long-standing tetraplegia can use a neural interface system to move and click a computer cursor and to control physical devices," said the scientists in their Nature paper.
"One of the study participants, implanted with the sensor five years earlier, also used a robotic arm to drink coffee from a bottle," said the researchers.
This participant was Cathy, who had a stroke 15 years ago and used her thoughts to steer a robot arm, which grasped a flask of coffee and lifted it to her lips. You can catch the video here of Cathy drinking the coffee and smiling:
Video courtesy of Nature Video Channel on YouTube
John Donoghue, director of the Brown Institute for Brain Science in Providence, Rhode Island, is leading the BrainGate trials. He told Nature yesterday there is still a long way to go.
"Movements right now are too slow and inaccurate – we need to improve decoding algorithms," said Donoghue.
The BrainGate trial uses two types of robotic arm: the DEKA Arm System, which is being developed for prosthetic limbs in collaboration with US military, and a heavier robot arm that the German Aerospace Centre is developing as an external assistive device.
On BrainWave.org, the scientists said another goal of the study is to determine the participants’ ability to operate communication software, such as email, by imagining the movement of their own hands. However, they said this last study is invasive and would require surgery.
Currently, the scientists are recruiting participants for a clinical study at both Massachusetts General Hospital in Boston and Stanford University Medical Center.