Peripheral nerve signal recording and processing for artificial limb control.

In order to take full advantage of modern multiple-degree of freedom prosthetic limbs, robust and natural control signals are needed. Previous work has shown that beamforming provides a method to extract such signals from peripheral nerve activity [1]. This paper describes in vivo experiments done to validate that method in a more realistic case. A 16-channel Flat Interface Nerve Electrode was used to record from the Sciatic nerve in Rabbit, while the distal Tibial and Peroneal branches were stimulated. Beamforming provided R(2)=0.7 ± 0.2, an improvement of 0.12 ± 0.06 over the a posteriori chosen best channels. When more realistic signals were generated using kHz-level stimulation, the beamforming filters were able to distinguish which branch was being stimulated, and in many cases how strongly, over a large range of stimulation intensities.