The system – which wirelessly transmits decoded brain signals to stimulate the muscles responsible for leg movement – represents the first time a neural prosthetic has restored locomotion in a primate.
“The system we have developed uses signals recorded from the motor cortex of the brain to trigger coordinated electrical stimulation of nerves in the spine that are responsible for locomotion,” says engineer David Borton from Brown University.
In the system, which builds upon previous sensor technology called BrainGate, a pill-sized electrode array is implanted in the brain to capture movement signals generated by the motor cortex.
To calibrate the system, the researchers implanted the neural interface in healthy macaques, so they could capture the animals’ brain signals that correspond to normal leg movement and locomotion.
The interface still requires a separate computer capable of decoding the signals, and more significantly, the wireless signals currently only get sent one way: from the brain to the legs.
Short of using the interface to restore movement when the sensors are activated, the system might also one day be used as a rehabilitation tool, to get people back on their feet and relearn, step by step, how to walk again without assistance.