Analog front-end circuitry for biphasic stimulus signal delivery finding use in neural stimulation

摘要

Front-end analog circuitry is described based on a sink-regulated H-bridge topology for delivery of biphasic stimulus signals that may be useful in neurostimulation. Stimulus current may be supplied using fully-integrated dynamic voltage supplies (DVSs), which may be controlled in closed-loop to have an output voltage approximately equal to the voltage of the electrode each supplies stimulus to. The stimulus waveform may be regulated by a single, low-voltage current-digital-to-analog converter (current-DAC), which can safely interface with the electrodes (which may be at high voltages) via high-voltage adapter (HVA) circuits. Example analog front-end circuitry may utilize the balancing stimulus current to discharge the electrode-tissue interface impedance (Z_E). In some examples, only after full (or sufficient) Z_E discharge has been detected is a DVS used to supply the remaining balancing stimulus.