N95 filtering facepiece<unk>  elastomeric air-purifying<unk> . This kind of<unk>  is reusable, with the filters being replaced periodically. Lab worker wearing a powered air-purifying<unk>  A<unk>  is a device designed to protect the wearer from inhaling hazardous atmospheres, including fumes, vapours, gases and particulate matter such as dusts and airborne pathogens such as viruses. There are two main categories: the air-purifying<unk> , in which respirable air is obtained by filtering a contaminated atmosphere, and the air-supplied<unk> , in which an alternate supply of breathable air is delivered. Within each category, different techniques are employed to reduce or eliminate noxious airborne contaminants. Air-purifying<unk> s range from relatively inexpensive single-use, disposable face masks sometimes referred to as a filtering facepiece<unk>  to more robust reusable models with replaceable cartridges called an elastomeric<unk> . Powered air-purifying<unk> s (PAPR), use a pump or fan to constantly move air through a filter and supply purified air into a mask, helmet or hood.
Respirator
Ventilator
Aspirator 
Resuscitator
Intensivist
Both respirator
TheraBreath 
Liquid ventilator