The mechanism used in our system to obtain oxygen-rich air is called Pressure Swing Adsorption.
A group of minerals called aluminosilicates have the ability to selectively adsorb (i.e. absorb and store on their surface) Nitrogen from the air, while allowing Oxygen to pass-through. We are using this property of aluminosilicates, more specifically of 13X Zeolite, to discard Nitrogen and produce oxygen-rich air.
Using a compressor with an after-cooler setup, we obtain compressed air which is dried through silica placed in the sacrificial bed. This dry air enters a column containing zeolite, that removes the Nitrogen present in the air. The oxygen-rich air now enters the product tank, whereupon the pressure is re-adjusted and delivered to the patient per-requirement.