Handcrafted Microwire Regenerative Peripheral Nerve Interfaces with Wireless Neural Recording and Stimulation Capabilities

Abstract

A scalable microwire peripheral nerve interface was developed, which interacted with regenerated peripheral nerves in microchannel scaffolds. Neural interface technologies are envisioned to facilitate direct connections between the nervous system and external technologies such as limb prosthetics or data acquisition systems for further processing. Presented here is an animal study using a handcrafted microwire regenerative peripheral nerve interface, a novel neural interface device for communicating with peripheral nerves. The neural interface studies using animal models are crucial in the evaluation of efficacy and safety of implantable medical devices before their use in clinical studies. 16-electrode microwire microchannel scaffolds were developed for both peripheral nerve regeneration and peripheral nerve interfacing. The microchannels were used for nerve regeneration pathways as a scaffolding material and the embedded microwires were used as a recording electrode to capture neural signals from the regenerated peripheral nerves. Wireless stimulation and recording capabilities were also incorporated to the developed peripheral nerve interface which gave the freedom of the complex experimental setting of wired data acquisition systems and minimized the potential infection of the animals from the wire connections. A commercially available wireless recording system was efficiently adopted to the peripheral nerve interface. The 32-channel wireless recording system covered 16-electrode microwires in the peripheral nerve interface, two cuff electrodes, and two electromyography electrodes. The 2-channel wireless stimulation system was connected to a cuff electrode on the sciatic nerve branch and was used to make evoked signals which went through the regenerated peripheral nerves and were captured by the wireless recording system at a different location. The successful wireless communication was demonstrated in the result section and the future goals of a wireless neural interface for chronic implants and clinical trials were discussed together. Sensor Networks and Data CommunicationsCitation: Ajam A, Hossain R, Tasnim N, Castanuela L, Ramos R, et al. (2016) and develop an isolated neural signal communication. Along with peripheral nerve regeneration, the microwires on the nodes of Ranvier can cover and record neural signals selectively from an isolated neural signal source. The microchannel and microwire are long enough to cover and record neural signals from the isolated nerve branch by structural selectivity during nerve regeneration. Methods Fabrication of PDMS scaffoldsMicrofluidic channel scaffolds were developed to direct peripheral nerve growth. 50 wires (160 µm in diameter) were tightly packed into Silastic ® tubes (OD 1.96 mm, ID 1.47 mm; Cat. No. 508-006, Dow Corning, MI) and then were cast in liquid PDMS (Sylgard ® 184, Dow Corning, MI) with a 10:1 base to curing agent ratio. They were placed in a vacuum chamber until all air dissipated and then were placed in an oven for 2 hours at 90ºC to all...