A Multi-Channel Low-Power System-on-Chip for in Vivo Recording and Wireless Transmission of Neural Spikes

Journal of Low Power Electronics and Applications

Andrea Bonfanti¹  Maria Ceravolo¹  Guido Zambra¹  Riccardo Gusmeroli¹  Gytis Baranauskas²  Gian Nicola Angotzi²  Alessandro Vato²  Emma Maggiolini²  Marianna Semprini²  Alessandro Sottocornola Spinelli¹ 

[1] Dipartimento di Elettronica e Informazione, Politecnico di Milano, Via Golgi 40, Milano 20133, Italy;Italian Institute of Technology (IIT), Department of Robotic, Brain and Cognitive Science, Genova 16163, Italy

关键词: neural recording;    action potential;    low-noise amplifier;    wireless transmitter;    bio-telemetry;    FSK;    Manchester-encoding;   

DOI  :  10.3390/jlpea2040211

来源: mdpi

【 摘 要 】

This paper reports a multi-channel neural spike recording system-on-chip with digital data compression and wireless telemetry. The circuit consists of 16 amplifiers, an analog time-division multiplexer, a single 8 bit analog-to-digital converter, a digital signal compression unit and a wireless transmitter. Although only 16 amplifiers are integrated in our current die version, the whole system is designed to work with 64, demonstrating the feasibility of a digital processing and narrowband wireless transmission of 64 neural recording channels. Compression of the raw data is achieved by detecting the action potentials (APs) and storing 20 samples for each spike waveform. This compression method retains sufficiently high data quality to allow for single neuron identification (spike sorting). The 400 MHz transmitter employs a Manchester-Coded Frequency Shift Keying (MC-FSK) modulator with low modulation index. In this way, a 1.25 Mbit/s data rate is delivered within a limited band of about 3 MHz. The chip is realized in a 0.35 µm AMS CMOS process featuring a 3 V power supply with an area of 3.1 × 2.7 mm² . The achieved transmission range is over 10 m with an overall power consumption for 64 channels of 17.2 mW. This figure translates into a power budget of 269 µW per channel, in line with published results but allowing a larger transmission distance and more efficient bandwidth occupation of the wireless link. The integrated circuit was mounted on a small and light board to be used during neuroscience experiments with freely-behaving rats. Powered by 2 AAA batteries, the system can continuously work for more than 100 hours allowing for long-lasting neural spike recordings.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.