IEC 60601-2-40:2016 applies to the basic safety and essential performance of electromyographs and evoked response equipment, hereafter referred to as ME equipment. ME equipment intended for transcutaneous electrical nerve stimulators and electrical muscle stimulators are excluded (covered by IEC 60601-2-10). This second edition cancels and replaces the first edition of IEC 60601-2-40 published in 1998. This edition constitutes a technical revision.