A VLSI Neural Monitoring System With Ultra-Wideband Telemetry for Awake Behaving Subjects

TLDR

Long‑term monitoring of neuronal activity in awake behaving subjects yields fundamental insights into brain dynamics for neuroscience and neuroengineering. The authors present a miniature, lightweight, low‑power recording system for monitoring neural activity in awake behaving animals. The system comprises two custom VLSI chips—a 0.5‑μm CMOS neural interface and a 0.5‑μm silicon‑on‑sapphire ultra‑wideband transmitter—along with a digital interface board, battery, and housing, and it amplifies, filters, digitizes, and wirelessly transmits 16 channels at 1 Mb/s while weighing 24 g and drawing 4.8 mA for up to 40 h on a 3.7‑V, 200‑mAh Li‑ion battery. Benchtop characterizations and in‑vivo multichannel recordings from awake rats demonstrate the system’s performance.

Abstract

Long-term monitoring of neuronal activity in awake behaving subjects can provide fundamental information about brain dynamics for neuroscience and neuroengineering applications. Here, we present a miniature, lightweight, and low-power recording system for monitoring neural activity in awake behaving animals. The system integrates two custom designed very-large-scale integrated chips, a neural interface module fabricated in 0.5 μm complementary metal-oxide semiconductor technology and an ultra-wideband transmitter module fabricated in a 0.5 μm silicon-on-sapphire (SOS) technology. The system amplifies, filters, digitizes, and transmits 16 channels of neural data at a rate of 1 Mb/s. The entire system, which includes the VLSI circuits, a digital interface board, a battery, and a custom housing, is small and lightweight (24 g) and, thus, can be chronically mounted on small animals. The system consumes 4.8 mA and records continuously for up to 40 h powered by a 3.7-V, 200-mAh rechargeable lithium-ion battery. Experimental benchtop characterizations as well as in vivo multichannel neural recordings from awake behaving rats are presented here.