A Wireless Optoelectronic Neuroscience Platform for Chronic Fluorescence Sensing in Freely Behaving Rodents

• Main Authors: Khiarak, M. Noormohammadi, Gagnon-Turcotte, G., Martianova, E., Martel, C. Bories S., Proulx, C. D., De Koninck, Y., Gosselin, B.
• Format: Conference Proceeding
• Language: English
• Subjects: Biomedical optical imaging; Biosensors; fiber photometry; fluorescence; freely moving; Modulation; neuroscience; Optical sensors; optoelectronic biosensor; Photometry; Sigma Delta modulator; wireless; Wireless communication; Wireless sensor networks
• ISSN: 1558-4615; 2694-0604
• DOI: 10.1109/EMBC.2018.8512653

We present a new head mountable wireless fiber biophotometry microsystem conceived to detect fluorescent signal fluctuations correlated with neuronal activity. The proposed system incorporates all aspects of a conventional tethered fiber-based biophotometry system encompassed into a wireless microsystem. The interface includes an LED as excitation light source, a custom designed CMOS biosensor, a multimode fiber, a microcontroller (MCU), and a wireless data transceiver enclosed within a 3D-printed, small and light weight, plastic housing. Precisely, the system incorporates a new optoelectronic biosensor merging two individual building blocks, namely a low-noise sensing front-end and a 2 nd order continuous-time ΣΔ modulator (CTSDM), into a single module for enabling high-sensitivity and high energy-efficiency photo-sensing. The proposed CMOS biosensor is implemented in a 0.18-μm CMOS technology, consuming 41 μW from a 1.8-V supply voltage, while achieving a peak dynamic range of 86 dB over a 50-Hz input bandwidth at a 20-kS/s sampling rate. This new interface opens new avenues for conducting in-vivo experiments with live animals.