The Brain

Thought-Powered Wheelchair Could Return Mobility To People With Paralysis

March 3, 2016 | by Justine Alford

Photo credit: If successful in humans, it could offer paralyzed patients more independence. KPG_Payless/Shutterstock

One day, it may well be possible to repair severe spinal cord injuries so that people with paralysis can regain mobility. But regenerating these nerves is fraught with difficulty; hence some scientists are looking at other ways to help such patients become more independent, like thought-powered devices. And this field seems to be coming along leaps and bounds, as demonstrated by a new study in which monkeys were able to navigate a robotic wheelchair using a brain chip.

Now, this isn’t actually the first time that a mind-controlled wheelchair has been showcased; reports of such systems actually go back quite a few years. But there is an important difference between these earlier systems and the one presented in the present study. Before, brainwaves were read using external electrodes that were fitted inside a cap. This time around, scientists were aiming for greater navigation accuracy and so implanted the electrodes into the brain.

And they had reason to believe that this technique could work: Studies have already shown that both monkeys and humans are able to control artificial limbs via brainwave-reading chips, with one tetraplegic woman even managing to feed herself and fly a jet simulator. Since wheelchairs are the predominant way that people with motor disabilities get around, scientists were keen to find out whether the technology could be applied to these devices, especially given that around 70 percent of paralyzed patients have said they’d undergo the surgery if it meant they could control assistive gadgets.

Described in Scientific Reports, the team began by implanting chips capable of recording neural activity into several different regions of the brain involved in the control of movement, the motor cortex. The two monkey subjects were then placed in robotic wheelchairs that were preprogrammed to navigate towards a food reward. During these sessions, the monkeys’ brainwaves were wirelessly beamed towards a computer that attempted to decode the signals, linking the wheelchair movements to certain patterns of brain activity.

The gif above shows one of the monkeys using the thought-powered wheelchair. Shawn Rocco/Duke Health

After multiple training sessions, the monkeys were challenged with navigating the chair towards the food reward using only their thoughts, which were continuously being translated by the wireless system. The computer was successfully able to decode the monkeys’ thoughts into directional movements, allowing the primates to learn how to use the system to reach the food. With more practice, the monkeys were able to improve their navigational skills, which could even suggest that the training exercises may have even led to changes at the neural level that could boost brain function.

With more and more studies demonstrating the potential of such “brain-machine-interfaces” (BMIs), it may not be too long before they can be offered to more patients suffering from paralysis, helping them to become more independent in their lives. “BMIs will likely have a profound clinical impact in the future,” the researchers conclude. 

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