A system and method to interface with multiple groups of axons in several fascicles of peripheral nerves

Abstract

Background Several neural interface technologies that stimulate and/or record from groups of axons have been developed. The longitudinal intrafascicular electrode (LIFE) is a fine wire that can provide access to a discrete population of axons within a peripheral nerve fascicle. Some applications require, or would benefit greatly from, technology that could provide access to multiple discrete sites in several fascicles. New Method The distributed intrafascicular multi-electrode (DIME) lead was developed to deploy multiple LIFEs to several fascicles. It consists of several (e.g. six) LIFEs that are coiled and placed in a sheath for strength and durability, with a portion left uncoiled to allow insertion at distinct sites. We have also developed a multi-lead multi-electrode (MLME) management system that includes a set of sheaths and procedures for fabrication and deployment. Results A prototype with 3 DIME leads was fabricated and tested in a procedure in a cadaver arm. The leads were successfully routed through skin and connective tissue and the deployment procedures were utilized to insert the LIFEs into fascicles of two nerves. Comparison with Existing Method(s) Most multi-electrode systems use a single-lead, multi-electrode design. For some applications, this design may be limited by the bulk of the multi-contact array and/or by the spatial distribution of the electrodes. Conclusion We have designed a system that can be used to access multiple sets of discrete groups of fibers that are spatially distributed in one or more fascicles of peripheral nerves. This system may be useful for neural-enabled prostheses or other applications.

Interfaces with the peripheral nervous system for the control of a neuroprosthetic limb: a review

“…Furthermore, the distributed intra-fascicular multielectrode (DIME), an evolution of LIFE, is designed in order to access multiple fascicles within a nerve. For the aim of providing more selectivity, it is composed of multiple LIFEs with their proximal ends coiled in a sheath to provide robustness and facilitate implantation [93]. Another study proposed a 15electrode array lead that trifurcates into three groups of five LIFEs, and showed that it had sufficient mechanical fatigue resistance.…”

Bionic Intrafascicular Interfaces for Recording and Stimulating Peripheral Nerve Fibers

“…The longitudinal orientation, which aligns the fine wire with the nerve fibers, further reduces the potential for mechanical stress-induced damage or movement. It is possible to place multiple LIFEs in one fascicle, in different fascicles within one nerve or in multiple nerves to provide access to multiple sites that are distributed in a region of the body [50]. The length of the exposed region, which is designed to be approximately equivalent to internodal spacing (1 mm), increases the likelihood of proximity to a node; the longitudinal placement, which aligns the exposed region parallel to the fibers, minimizes the number of fibers in close proximity.…”

“…Since the electrodes must be placed within a fascicle, insertion requires a more detailed and lengthy surgical procedure [50,56]. Both the insertion procedure and long-term presence within the fascicle present risks of trauma to the nerve fibers and neighboring tissue [53].…”

Neural interfaces for somatosensory feedback

“…invasive penetrates the perineurium to place components inside the fascicle. Examples include the Longitudinal IntraFascicular Electrode (LIFE) [97,98], Transverse Intrafascicular Multichannel Electrode (TIME) [99] and Utah Slanted Electrode Array [100].…”