A voltage-controlled current source with regulated electrode bias-voltage for safe neural stimulation

A current source for neural stimulation is presented which converts arbitrary voltage signals to current-controlled signals while regulating the offset-voltage across the stimulation electrodes in order to keep the electrodes in an electrochemical state that allows for injecting a maximum charge. The offset-voltage can either be set to 0 V or to a bias-voltage, e.g. of a few 100 mV, as it can be advantageous for fully exploiting the charge injection capacity of iridium oxide electrodes.