A wireless brain-machine-interface (BMI) which allows a monkey to control the movements of a robotic wheelchair is described in Scientific Reports this week. The results suggest that BMIs similar to this one may be able to help restore mobility to severely paralysed patients in the future.
BMIs have previously been developed which allow primates to use cortical activity to control artificial limbs. However, it is unknown if recordings from cortical implants in the brain could be translated into whole-body movements.
Miguel Nicolelis and colleagues implanted two rhesus monkeys with multi-electrode arrays that allowed wireless recordings to be made of premotor and sensorimotor cortical neurons in the brain. The monkeys were then seated in a robotic wheelchair and passively observed the movements of the chair as it navigated around a space, in order to train a BMI decoder. Once this had been completed, the monkeys attempted to navigate in the wheelchair, using the wireless BMI system, from one of three starting positions to a target location, where a food reward (grape) had been placed. The authors found that the BMI was capable of translating the monkeys’ brain activity into directional movements in the wheelchair in order to complete the task. They also found that over time the monkeys improved their ability to navigate in the wheelchair, which may have been mediated by changes in their brain structure in response to training.