Improving the signal-to-noise ratio in recordings with thin-film longitudinal intra-fascicular electrodes using shielding cuffs

An elegant solution to the problem of instrumenting paralyzed limbs with artificial sensors for use with closed-loop FES systems is to use natural sensors, such as muscle afferent activity as feedback for the artificial controller. Longitudinal intra-fascicular electrodes (LIFEs) are electrodes that have shown promise in this application. As a peripheral nerve interface, they are designed to be placed inside the peripheral nerve, but near potentially active muscles and the stimulating electrode. Artefacts from EMG and stimulation remain limiting factors in signal acquisition. Here, we present a technique for improving the signal-to-noise ratio which consists of wrapping a shield around the implant site of the recording electrode. Preliminary results obtained during in-vivo experiments suggest that the shielding increases the level of the neural signal in the recordings.