Extending the dynamic range of implantable real-time neurochemical monitoring systems

In this paper, we present a low-cost, low-power integrated dynamic background subtraction scheme for wireless real-time neurochemical monitoring in freely-moving animals. We derive the theoretical dynamic range enhancement of the proposed scheme and analyze the effects that quantization noise and output swing, normalized to full scale, impose on this figure. Preliminary simulation results indicate an effective resolution of 14 bits for a swing of 2.5% full scale using a 9-bit successive- approximation register (SAR) analog-to-digital converter (ADC) in a two-step conversion approach.