title: A multi-channel low-power system-on-chip for single-unit recording and narrowband wireless transmission of neural signal.
abstract: This paper reports a multi-channel neural recording system-on-chip (SoC) with digital data compression and wireless telemetry. The circuit consists of a 16 amplifiers, an analog time division multiplexer, an 8-bit SAR AD converter, a digital signal processor (DSP) and a wireless narrowband 400-MHz binary FSK transmitter. Even though only 16 amplifiers are present in our current die version, the whole system is designed to work with 64 channels demonstrating the feasibility of a digital processing and narrowband wireless transmission of 64 neural recording channels. A digital data compression, based on the detection of action potentials and storage of correspondent waveforms, allows the use of a 1.25-Mbit/s binary FSK wireless transmission. This moderate bit-rate and a low frequency deviation, Manchester-coded modulation are crucial for exploiting a narrowband wireless link and an efficient embeddable antenna. The chip is realized in a 0.35- εm CMOS process with a power consumption of 105 εW per channel (269 εW per channel with an extended transmission range of 4 m) and an area of 3.1 × 2.7 mm(2). The transmitted signal is captured by a digital TV tuner and demodulated by a wideband phase-locked loop (PLL), and then sent to a PC via an FPGA module. The system has been tested for electrical specifications and its functionality verified in in-vivo neural recording experiments.
authors.affiliation: Dipartimento di Elettronica e Informazione, Politecnico di Milano, piazza L. da Vinci 32, 20133, Italy. bonfanti@elet.polimi.it
authors.forename: A
authors.initials: A
authors.lastname: Bonfanti
authors.forename: M
authors.initials: M
authors.lastname: Ceravolo
authors.forename: G
authors.initials: G
authors.lastname: Zambra
authors.forename: R
authors.initials: R
authors.lastname: Gusmeroli
authors.forename: A S
authors.initials: AS
authors.lastname: Spinelli
authors.forename: A L
authors.initials: AL
authors.lastname: Lacaita
authors.forename: G N
authors.initials: GN
authors.lastname: Angotzi
authors.forename: G
authors.initials: G
authors.lastname: Baranauskas
authors.forename: L
authors.initials: L
authors.lastname: Fadiga
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D011211:Electric Power Supplies; D004569:Electroencephalography / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D009474:Neurons / Q000502:physiology*; D051381:Rats; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013686:Telemetry / Q000295:instrumentation*