This document applies to the basic safety and essential performance of a high-frequency ventilator (HFV) in combination with its accessories, hereafter referred to as MEequipment:intended for use in an environment that provides specialized care for patients whose conditions can be life-threatening and who can require comprehensive care and constant monitoring in a professional healthcare facility;NOTE1 For the purposes of this document, such an environment is referred to as a critical care environment. High-frequency ventilators for this environment are considered life-sustaining.NOTE2 For the purposes of this document, such a high-frequency ventilator can provide transport within a professional healthcare facility (i.e., be a transit-operable ventilator).NOTE3 A high-frequency ventilator intended for use in transport within a professional healthcare facility is not considered as a ventilator intended for the emergency medical services environment.intended to be operated by a healthcare professional operator;intended for those patients who need differing levels of support from artificial ventilation including ventilator-dependent patients; andcapable of providing more than 150 inflations/min.There are three principal designations of HFV:high-frequency percussive ventilation [HFPV, with a typical HFV frequency of (60 to 1000) HFV inflations/min];high-frequency jet ventilation [HFJV, with a typical HFV frequency of (100 to 1500) HFV inflations/min]; andhigh-frequency oscillatory ventilation [HFOV, with a typical HFV frequency of (180 to 1200) HFV inflations/min and typically having an active expiratory phase].Additionally, HFV designations can be combined together or with ventilation at rates less than 150inflations/min.*A high-frequency ventilator is not considered a physiologic closed loop-control system unless it uses a physiological patient variable to adjust the ventilation therapy settings.This document is also applicable to those accessories intended by their manufacturer to be connected to an HFV breathing system, or to a high-frequency ventilator, where the characteristics of those accessories can affect the basic safety or essential performance of the high-frequency ventilator.If a clause or subclause is specifically intended to be applicable to MEequipment only, or to MEsystems 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 MEequipment and to MEsystems, as relevant.Hazards inherent in the intended physiological function of MEequipment or MEsystems within the scope of this document are not covered by specific requirements in this document except in 7.2.13 and 8.4.1 of IEC60601-1:2005.NOTE4 Additional information can be found in 4.2 of IEC60601-1:2005+AMD1:2012.This document is not applicable to MEequipment that is intended solely to augment the ventilation of spontaneously breathing patients within a professional healthcare facility.This document does not specify the requirements for:non-high-frequency ventilators or accessories which provide conventional ventilation for use in critical care environments, which are given in ISO80601-2-12[23];.NOTE5 An HFV can incorporate conventional critical care ventilator operational modes, in which case ISO80601-2-12 is applicable to those modes.ventilators or accessories intended for anaesthetic applications, which are given in ISO806