Regenerative Electrodes for Peripheral Nerve Interfacing

Abstract

AbstractRegenerative peripheral neural interfaces are devices which are designed to interface peripheral nerve fibers that have regenerated through or past their geometry. Since the nerve is first severed prior to regeneration through a device, they constitute the most invasive type of interface – their use is predicated on the implant being placed near the ends of stumps formed following nerve transection. Since peripheral nerve fibers regenerate vigorously following transection, these implants become completely embedded in the regenerated nerve trunk, and fibers can be guided into configurations uniquely suitable for interfacing. Despite the potency in near arbitrary rearrangement of nerve fasciculation, the term regenerative peripheral neural interface has historically been used to denominate a single device geometry – the sieve electrode. Over the last decade, this has changed, and the term has come to encompass a wide variety of distinct implementations. This chapter introduces peripheral nerve interfacing including peripheral nerve regeneration, the unique properties of regenerated nerve fibers, and the impact of these features on the use of regenerative interfaces. It further includes a discussion on lessons learned from early device implementations and detailed descriptions of contemporary regenerative interfaces including micro-channel electrodes, macro-sieve electrodes, and other notable device types. The chapter ends with a summary of computational device assessment and how theoretical and experimental findings both point toward the superiority of regenerative devices in bidirectional, neural interface applications.KeywordsSieve electrodeMicro-sieveMacro-sieveMicro-channelNerve regeneration