A Versatile Hermetically Sealed Microelectronic Implant for Peripheral Nerve Stimulation Applications

Dai Jiang; Fangqi Liu; Henry T Lancashire; Timothy A Perkins; Matthew Schormans; Anne Vanhoestenberghe; Nicholas De N Donaldson; Andreas Demosthenous

doi:10.3389/fnins.2021.681021

A Versatile Hermetically Sealed Microelectronic Implant for Peripheral Nerve Stimulation Applications

Front Neurosci. 2021 Jul 22:15:681021. doi: 10.3389/fnins.2021.681021. eCollection 2021.

Authors

Dai Jiang¹, Fangqi Liu¹, Henry T Lancashire², Timothy A Perkins², Matthew Schormans¹, Anne Vanhoestenberghe^{2

3}, Nicholas De N Donaldson², Andreas Demosthenous¹

Affiliations

¹ Department of Electronic and Electrical Engineering, University College London, London, United Kingdom.
² Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom.
³ Division of Surgery and Interventional Science, Aspire Centre for Rehabilitation Engineering and Assistive Technology, University College London, London, United Kingdom.

Abstract

This article presents a versatile neurostimulation platform featuring a fully implantable multi-channel neural stimulator for chronic experimental studies with freely moving large animal models involving peripheral nerves. The implant is hermetically sealed in a ceramic enclosure and encapsulated in medical grade silicone rubber, and then underwent active tests at accelerated aging conditions at 100°C for 15 consecutive days. The stimulator microelectronics are implemented in a 0.6-μm CMOS technology, with a crosstalk reduction scheme to minimize cross-channel interference, and high-speed power and data telemetry for battery-less operation. A wearable transmitter equipped with a Bluetooth Low Energy radio link, and a custom graphical user interface provide real-time, remotely controlled stimulation. Three parallel stimulators provide independent stimulation on three channels, where each stimulator supports six stimulating sites and two return sites through multiplexing, hence the implant can facilitate stimulation at up to 36 different electrode pairs. The design of the electronics, method of hermetic packaging and electrical performance as well as in vitro testing with electrodes in saline are presented.

Keywords: hermetic seal package; implantable stimulator; microelectronics; power and data telemetry; wireless stimulation control.