A surgical tool including first connecting elements, contacting elements, and conductive elements. The contacting elements are configured to contact nerve tissue of a patient. The conductive elements extend from the connecting elements to the contacting elements. The conductive elements have respective insulative outer layers. The insulative outer layers isolate the conductive elements from each other. The first connecting elements are configured to connect to and receive monophasic stimulation pulses from second connecting elements on a modular stimulation module. The modular stimulation module is configured to connect to the tool and other tools via the second connecting elements. The conductive elements are configured to transfer the monophasic stimulation pulses from the connecting elements to the contacting elements.