Sensory and Motor Intent Signals Recorded by Regenerative Multielectrode Arrays

Advanced robotic limbs have human-like degrees-of-freedom and are sensorized. However, offering amputees naturalistic control and sensation/perception requires interfacing to the nervous system of the user with selectivity and sensitivity. Current peripheral neural interfaces include targeted muscle re-innervation, and myoelectric control and peripheral nerve electrodes, including cuff or FINE electrodes, indwelling tf-LIFE, TIME or regenerative sieve or Regenerative Multielectrode Interface (REMI) electrodes. However, identification of the nature of the electrical activity recorded by these interfaces remains challenging. Here, we report waveform characterization of neurophysiological activity recorded from a motor nerve (tibial), from a sensory nerve (sural) recorded using a dual REMI interface. We analyzed neural spike data recorded in animals 1–2 months after regeneration to their natural muscle and skin targets, that correlated with bipedal locomotion or evoked by von Frey activation of skin touch sensors. Motor waveforms exhibited biphasic and triphasic shapes, while sensory activity was monophasic. These results provide insight as to the shape of action potentials in the REMI and contribute to the characterization of motor and sensory neural activity.