Low power recording and digitizing circuits for neural prosthetics

Significant progress has been made in the field of neural prosthetics lately. In order to improve and invent novel wearable and implantable devices, low power consumption is one of the most important concerns. This article discusses low power circuits which are designed, fabricated and tested in our lab which are essential building blocks for neural prosthetics. The circuits include a nano-power current conveyor which senses picoscale to microscale current which corresponds to micro molar neurotransmitter concentration; a nano-power neural amplifier for action potential (AP) detection and amplification and a micro-power ΣΔ analog to digital convertor (ADC) to convert the analog signal (AP or neurotransmitter concentration) to digital codes. These circuits are fabricated in CMOS 0.18 μ technology and tested using recorded signals from posterior parietal cortex of a macaque monkey in our lab.