A Beta-Band Energy Detecting Circuit for Deep Brain Stimulator

This paper presents the design and measurement of a feature extraction circuit which is able to detect the pathological Beta-band oscillation related to the Parkinson's disease, so as to control the Deep Brain Stimulator. The proposed circuit includes a 2^nd-order transconductance-capacitance (Gm-C) filter and an analog multiplier. The operated signal range is improved by using a fully differential architecture; body input, source degeneration, gate degeneration, as well as a bump circuit are used to achieve low Gm and high input range. All transistors in the circuit are operated in the sub-threshold region with 1-volt supply voltage, thus the whole circuit consumes only 2.8uW. Finally, the measurement result of the input range is 400mVpp within 1% variation in Gm.