Review of Neural Sensing Methods in the Peripheral Nervous System

The peripheral nervous system (PNS) transmits sensory and motor information directly linked to a target organ or function and is thus a target for neural sensing. Neural sensing involves measuring neural activity, which both implantable and wearable devices can achieve. Implantable Peripheral Nerve Interfaces (PNIs) may be formed from single-point electrodes or electrode arrays that can stimulate and record changes in potential from nerves. These electrodes may be either intraneural, implanted directly into the nerve, or extraneural, extracellular to the nerve so that the epineurium is not penetrated. The configuration of these electrodes influences the signal-to-noise ratio (SNR) of the recorded neural signal, and there is a range of signal-processing techniques to extract information from these recordings. Techniques that will be reviewed in this paper include feature selection, cross-correlation, velocity selective recording (VSR), distribution of conduction velocity (DCV), spatio-temporal methods, and magnetoneurography (MNG). This mini-review introduces current methods for measuring neural activity within the PNS, highlighting the compatibility of specific methodologies and techniques for different applications.