Restoring sensorimotor function in individuals with severe paralysis remains an important challenge in the field of medicine. Here we show, for the first time, an individual with severe upper-limb sensorimotor impairment can interact with real-world objects through another individual using an implanted brain-computer interface (iBCI) and wireless muscle activation, while also engaging in cooperative rehabilitation. This 'human avatar' paradigm enabled the iBCI study participant to generate motor intent signals, decoded in real time, to control the hand of other participants wirelessly through high resolution neuromuscular electrical stimulation. Working with an able-bodied participant, the iBCI participant achieved volitional control of the other participant's hand to discriminate objects of different compliance with 64% accuracy (p < 0.001) under blindfolded conditions. Discrimination was enabled by an S1 encoding paradigm combining multi-electrode recruitment and graded amplitude, which yielded perceptual accuracies exceeding 90% during calibration. Extending this paradigm, the iBCI participant worked with another participant with upper limb impairment and collaborated in a cooperative task: the iBCI participant's decoded motor commands drove spinal cord and neuromuscular stimulation in the other participant's arm, enabling bottle pouring with a 94% success rate (p < 0.0001). Qualitative interviews revealed strong subjective satisfaction, highlighting the potential of this form of cooperative rehabilitation. These findings show that cortically interfaced human avatars can restore both motor control and discriminative sensation across individuals, introducing a new framework for cooperative iBCI-based rehabilitation and perhaps even remote human interaction in the future.
Cater et al. (Mon,) studied this question.