Continuous neural control of a bionic limb restores biomimetic gait after amputation

Current bionic legs use predefined robotic control architectures, limiting their versatility. This study hypothesized that continuous neural control of a bionic limb, augmented by residual muscle afferents, could restore biomimetic gait after below-knee amputation. A neuroprosthetic interface with surgically connected agonist-antagonist muscles and muscle-sensing electrodes was used in seven leg amputees. The interface augmented residual muscle afferents by 18% of biologically intact values, increasing maximum neuroprosthetic walking speed by 41% and enabling biomimetic adaptation to various speeds and environments. Results suggest even small afferent augmentation restores biomimetic gait under continuous neuromodulation.

Hyungeun Song, Tsung-Han Hsieh, Seong Ho Yeon, Tony Shu, Michael Nawrot, Christian F. Landis, Gabriel N. Friedman, Erica A. Israel, Samantha Gutierrez-Arango, Matthew J. Carty, Lisa E. Freed, Hugh M. Herr