A VLSI neural monitoring system with ultra-wideband telemetry for awake behaving subjects

Abstract

Long term monitoring of neuronal activity in awake behaving subjects can provide fundamental information about brain dynamics for both neuroscience and neuroengineering applications. Recent advances in VLSI systems has focused on designing wireless neural recording systems which can be mounted on animals and acquire neural signals in real time. These advances provide an unparalleled opportunity to study phenomenon such as neural plasticity in both a basic science setting (learning and memory), and also a clinical setting (injury and recovery). Here we present an integrated VLSI system for wireless telemetry of the entire spectrum of neural signals, spikes, local field potentials, electrocorticograms (ECoG) and electroencephalograms (EEG). The system integrates two custom designed VLSI chips, a 16 channel neural interface which can amplify, filter and digitize neural data up to 16 kS/sec and 12 bits and a low power ultra-wideband (UWB) chip which can transmit data at rates up to 14 Mbps. The entire system which includes these VLSI circuits, a digital interface board and a battery, is small, 1.2×1.2×2.6 in3, and light weight, 33 grams, so it can be chronically mounted on a rat. The system consumes 32.8 mA at 3.3V and can record for 6 hours running from the 200 mAh coin cell battery. Bench-top and in vitro characterization of the system showed comparable performance to the wired recording system.