Authors:
Dimitris Firfilionis
;
JunWen Luo
and
Patrick Degenaar
Affiliation:
uSystems group, Newcastle University, Newcastle upon Tyne and U.K.
Keyword(s):
Optogenetics, Optical Stimulation, Electrical Recording, Closed-loop Processing, Brain-computer Interfaces.
Related
Ontology
Subjects/Areas/Topics:
Biomedical Engineering
;
Biomedical Instruments and Devices
;
Brain-Computer Interfaces
;
Devices
;
Human-Computer Interaction
;
Physiological Computing Systems
Abstract:
In this paper, we present an optogenetic platform with simultaneous electrical recording and optical stimulation, combined with closed-loop processing capabilities. The neural interface Application Specific Integrated Circuit (ASIC) placed on the head-stage provides four low noise (1.15 μVrms) recording channels, targeting Local Field Potential (LFP) recording. For stimulation it provides six independently addressable optical driver circuits, which offer both intensity and pulse-width modulation for high radiance LEDs. The ASIC also includes a fully-digital Serial Peripheral Interface (SPI) embedded within a Finite State Machine (FSM). This allows the ASIC to be controlled by external embedded controllers. The low power microcontroller used in this system is part of the Kinetis K22F sub-family (ARM Cortex M4), and is responsible for controlling the ASIC and storing the recorded data in a 1GB μSD card. Apart from the neural interface ASIC, which was implemented on a 0.35 μm CMOS tec
hnology, the head-stage and embedded control units were built using off-the-self components and rigid PCBs. The embedded control unit PCB occupies a space of 25x22 mm, while the head-stage has a size of 10x10 mm. The two units are connected via a 10-way Flat Flexible Cable (FFC), which provides power and clock signals, and bidirectional communication though the SPI interface.
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