Adaptive spike detection method based on capacitor arrays dedicated to implantable neural recording microsystems

An analog spike detector circuit is presented, which adaptively generates a threshold level for spike detection based on hard-thresholding. Operation of the circuit was tested not only with a neural signal obtained from real in-vivo recording from a live animal, but also with a large sinusoidal baseline variation intentionally added to examine the capability of the circuit to track baseline variations as large as 50mV. The circuit runs at 3.3V supply voltage and dissipates 270μW.