A neurorobotic platform for locomotor prosthetic development in rats and mice

Objectives. We aimed to develop a robotic interface capable of providing finely-tuned,

multidirectional trunk assistance adjusted in real-time during unconstrained locomotion in rats

and mice. Approach. We interfaced a large-scale robotic structure actuated in four degrees of

freedom to exchangeable attachment modules exhibiting selective compliance along distinct

directions. This combination allowed high-precision force and torque control in multiple

directions over a large workspace. We next designed a neurorobotic platform wherein real-time

kinematics and physiological signals directly adjust robotic actuation and prosthetic actions. We

tested the performance of this platform in both rats and mice with spinal cord injury. Main

Results. Kinematic analyses showed that the robotic interface did not impede locomotor

movements of lightweight mice that walked freely along paths with changing directions and

height profiles. Personalized trunk assistance instantly enabled coordinated locomotion in mice

and rats with severe hindlimb motor deficits. Closed-loop control of robotic actuation based on

ongoing movement features enabled real-time control of electromyographic activity in antigravity

muscles during locomotion. Significance. This neurorobotic platform will support the

study of the mechanisms underlying the therapeutic effects of locomotor prosthetics and

rehabilitation using high-resolution genetic tools in rodent models.