'Ventilator' or 'Respirator'?
What to Know
Typically, a ventilator is a a device used to maintain artificial breathing or circulate fresh air, while a respirator is a mask used to protect the wearer from particulates in the air. Note that historically, respirator has been confused with ventilator often enough that it has a secondary definition similar to that of ventilator.
The COVID-19 pandemic has, for many people across the globe, brought about large questions, questions such as 'should I rethink my career?' 'why didn't anyone tell me that children are difficult to live with?' and 'what is the difference between a ventilator and a respirator?' Excellent questions all, and our answers are 'probably,' 'funny!' and 'see below.'
Ventilators vs. Respirators
The short answer is that ventilators are devices (designed to assist a patient breathe), and respirators are masks (designed to protect the wearer). The longer answer will, as longer answers so often do, slightly confuse things, so if you're looking for brevity and a misplaced feeling of clarity you should stop reading now.
The first definition we give for ventilator is the word's original sense, in use since the first half of the 18th century: "a device for introducing fresh air or expelling foul or stagnant air." The second sense is the one which is more often used today: "a device for maintaining artificial respiration especially : a mechanized device that enables the delivery or movement of air and oxygen into the lungs of a patient whose breathing has ceased, is failing, or is inadequate; a mechanical ventilator" This definition includes the following note: "Modern, computerized mechanical ventilators typically monitor and customize gas delivery, maintain a constant pressure in the lungs to prevent the alveoli from collapsing, and deliver air and oxygen to the lungs by way of a tube inserted into the trachea through the mouth or nose."
We likewise offer two definitions for respirator. The first is the aforementioned one: "a mask or device worn over the mouth and nose to protect the respiratory system by filtering out dangerous substances (such as dusts, fumes, or bacteria) from inhaled air." This definition is also accompanied by a note: "Particulate respirator masks are only able to filter out particles and are not effective against gases or vapors. A numerical rating (such as 95 or 99) is sometimes assigned to such a respirator to indicate the percentage of particles filtered. A letter may also be assigned to indicate whether it is somewhat resistant (R), not resistant (NR), or strongly resistant (P) to the degrading effects of oil on proper respirator function."
Respirators Can Sometimes be Ventilators
However (and here we should note that however, although not defined as such, often functions as a word signifying that confusion is soon upon us), the second definition we give for respirator is "a device for maintaining artificial respiration; ventilator (sense b)." Why would we do such a thing? Because people have been using respirator to mean ventilator for a very long time. The 'mask' sense of respirator is older, dating to the first half of the 19th century, but the 'device' (or 'ventilator') sense of this word is almost as old, in use since the 1850s.
It can be confusing, as both words are concerned with breathing, or respiratory functions, and there is quite a bit of semantic overlap. If you are concerned about misuse simply restrict your use of respirator to the mask that protects the wearer (and others), and that of ventilator to the device that assists in breathing.