This International Standard applies to the basic safety and essential performance of a ventilator in combination with its accessories, hereafter referred to as ME equipment, intended for use in critical care environments in healthcare institutions and transport within the healthcare institution. This International Standard is applicable to ME equipment or an ME system intended to be attended by a professional operator for those patients who are dependent on ventilatory support. such ventilators are considered life-supporting me equipment. this international standard also applies to those characteristics of accessories intended by their manufacturer to be connected to the breathing system or a ventilator that can affect basic safety and essential performance of the ventilator.