A<unk>  is an early implementation of the<unk>  used for cardiopulmonary bypass. It has since been supplanted by the membrane<unk>  as a result of advances in material science. Some continue to promote it as a low-cost alternative allowing greater self-sufficiency.
Bubble oxygenator
Membrane oxygenator
Elastomeric respirator
Venturi mask
N95 respirator
Gas mask
Oxygen concentrator
Analytical nebulizer