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On-Probe Neural Interface ASIC for Combined Electrical Recording and Optogenetic Stimulation

Lookup NU author(s): Dr Reza Ramezani, Dr Yan Liu, Hubin Zhao, Dimitrios Firfilionis, Dr Anupam Hazra, Professor Mark Cunningham, Professor Andrew Jackson, Professor Patrick Degenaar



This is the authors' accepted manuscript of an article that has been published in its final definitive form by IEEE, 2018.

For re-use rights please refer to the publisher's terms and conditions.


Neuromodulation technologies are progressing frompacemaking and sensory operations to full closed loop control.In particular, optogenetics – the genetic modification of lightsensitivity into neural tissue allows for simultaneous opticalstimulation and electronic recording. This paper presents aneural interface ASIC for intelligent optoelectronic probes. Thearchitecture is designed to enable simultaneous optical neuralstimulation and electronic recording. It provides four low noise(2.08 μVrms) recording channels optimized for recording localfield potentials (0.1 – 300 Hz bandwidth, 5mV range, sampled10-bit@4 kHz), which are more stable for chronic applications.For stimulation it provides six independently addressable opticaldriver circuits, which can provide both intensity (8-bit resolutionacross a 1.1mA range) and pulse-width modulation for highradiance LEDs. The system includes a fully-digital interface usinga Serial Peripheral Interface (SPI) protocol to allow for use withembedded controllers. The SPI interface is embedded within aFinite State Machine (FSM) which implements a command interpreterthat can send out LFP data whilst receiving instructionsto control LED emission. The circuit has been implemented ina commercially-available 0.35μm CMOS technology occupyinga 1.95mm1.10mm footprint for mounting onto the head ofa silicon probe. Measured results are given for a variety ofbench-top, in vitro and in vivo experiments, quantifying systemperformance and also demonstrating concurrent recording andstimulation within relevant experimental models.Optogenetics, optrode, optoelectrode, neuralrecording, neural interface, implantable, channelrhodopsin

Publication metadata

Author(s): Ramezani R, Liu Y, Dekhoda F, Soltan A, Haci D, Zhao H, Firfilionis D, Hazra A, Cunningham M, Jackson A, Constandinou T, Degenaar P

Publication type: Article

Publication status: Published

Journal: IEEE Transactions on Biomedical Circuits and Systems

Year: 2018

Volume: 12

Issue: 3

Pages: 576-588

Print publication date: 01/06/2018

Online publication date: 15/05/2018

Acceptance date: 01/03/2018

Date deposited: 22/03/2018

ISSN (print): 1932-4545

ISSN (electronic): 1940-9990

Publisher: IEEE


DOI: 10.1109/TBCAS.2018.2818818


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Funder referenceFunder name
EPSRC (NS/A000026/1)
Wellcome Trust (102037/Z/13/Z)