Delivering diluted oxygen to a patient

A method for delivering diluted oxygen to a patient, comprising:

• providing a first port integral with a configurable oxygen delivery unit configured for decoupling a first end of an oxygen tube from the first port, wherein a second end of the oxygen tube is connected to a source of oxygen;
• and
• providing a second port integral with the configurable oxygen delivery unit configured for coupling the first end of the oxygen tube with the second port, each port comprising an orifice, each orifice (i) forming a jet flow of oxygen entering the device, and (ii) having the size that pertains to a particular oxygen concentration, wherein the size of each orifice determines a velocity of oxygen, at a predetermined flow rate, entering the device through the respective orifice, and wherein the velocity of oxygen is selected to entrain room air to achieve a predetermined oxygen concentration within the device, wherein different oxygen concentrations are associated with the first and second ports and wherein the configurable oxygen delivery unit is structured to enable selectively altering the oxygen concentration within the device from a first concentration to a second concentration by fluidly coupling the first end of the oxygen tube with an orifice pertaining to a particular oxygen concentration.