ISO 80601-2-12:2011 applies to the basic safety and essential performance of a ventilator in combination with its accessories, hereafter referred to as me equipment: intended to be attended by a professional operator for those patients who are dependent on mechanical ventilation; and intended for use in critical care environments in a professional healthcare facility or intended for use in transport within a professional healthcare facility. ISO 80601-2-12:2011 is also applicable to those accessories intended by their manufacturer to be connected to a breathing system, or to a ventilator, where the characteristics of those accessories can affect the basic safety or essential performance of the ventilator. ISO 80601-2-12:2011 is not applicable to me equipment or an me system operating in ventilation modes intended for patients who are not dependent on mechanical ventilation. ISO 80601-2-12:2011 is not applicable to me equipment or an me system intended for those patients who are not dependent on mechanical ventilation. If a clause or subclause is specifically intended to be applicable to me equipment only, or to me systems only, the title and content of that clause or subclause will say so. If that is not the case, the clause or subclause applies both to me equipment and to me systems, as relevant.