Remote-Controlled Fully Implantable Neural Stimulator for Freely Moving Small Animal

Abstract

The application of a neural stimulator to small animals is highly desired for the investigation of electrophysiological studies and development of neuroprosthetic devices. For this purpose, it is essential for the device to be implemented with the capabilities of full implantation and wireless control. Here, we present a fully implantable stimulator with remote controllability, compact size, and minimal power consumption. Our stimulator consists of modular units of (1) a surface-type cortical array for inducing directional change of a rat, (2) a depth-type array for providing rewards, and (3) a package for accommodating the stimulating electronics, a battery and ZigBee telemetry, all of which are assembled after independent fabrication and implantation using customized flat cables and connectors. All three modules were packaged using liquid crystal polymer (LCP) to avoid any chemical reaction after implantation. After bench-top evaluation of device functionality, the stimulator was implanted into rats to train the animals to turn to the left (or right) following a directional cue applied to the barrel cortex. Functionality of the device was also demonstrated in a three-dimensional (3D) maze structure, by guiding the rats to better navigate in the maze. The movement of the rat could be wirelessly controlled by a combination of artificial sensation evoked by the surface electrode array and reward stimulation. We could induce rats to turn left or right in free space and help their navigation through the maze. The polymeric packaging and modular design could encapsulate the devices with strict size limitations, which made it possible to fully implant the device into rats. Power consumption was minimized by a dual-mode power-saving scheme with duty cycling. The present study demonstrated feasibility of the proposed neural stimulator to be applied to neuroprosthesis research.

Soft subdermal implant capable of wireless battery charging and programmable controls for applications in optogenetics

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Current Stimulation of the Midbrain Nucleus in Pigeons for Avian Flight Control

“…A handheld, wireless neural stimulation controller and the implantable neurostimulator developed by the authors were used for the experiment [ 26 , 32 , 34 ]. The external controller was composed of a microcontroller (SPARTAN3A, Xilinx, San Jose, CA, USA) and a Zigbee communication module (CC2530, Texas Instruments, Dallas, TX, USA).…”

“…The pulse was modified in the range of 40.7–452.3 Hz for the frequency, 10.1–636.3 μs for the duration, and 0–10.23 mA for the amplitude. The size of the designed wireless stimulation device [ 34 ] for implant was 29 mm × 26 mm × 8 mm, and was hermetically packaged with LCP.…”

Investigation of stereotactic surgery for avian brain stimulation by a fully implanted wireless system

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