Nasal cannula apparatus for oxygen delivery and related methods

A nasal cannula apparatus, comprising:

• a body that defines a body chamber, the body adapted to engage a user generally above an upper lip;
• a pair of nasal cannula attached to the body, each nasal cannula of the pair of nasal cannula adapted to engage occlusively a naris in order to communicate fluidly between the naris and the body chamber via the nasal cannula;
• a supply tube in fluid communication with the body chamber to communicate a respiratory gas from a gas source into the body chamber for inhalation via the pair of nasal cannula;
• an inflow valve in fluid cooperation with the supply tube and the body chamber to control communication of the respiratory gas from the supply tube into the body chamber;
• a discharge tube in fluid communication with the body chamber to communicate an outflow gas from the body chamber, the outflow gas having been exhaled into the body chamber via the pair of nasal cannula;
• and
• wherein the inflow valve allows communication of the respiratory gas from the supply tube into the body chamber during inhalation and blocks communication of the respiratory gas from the supply tube into the body chamber during exhalation.

A method of respiratory therapy, comprising the steps of:

• attaching a body to the user generally between an upper lip and external nares with a pair of nasal cannula occlusively engaged with the nares of the user, the pair of nasal cannula being in fluid communication with a body chamber defined by the body;
• decreasing a chamber pressure within the body chamber to less than a supply pressure within a supply tube communicating with the body chamber by inhaling respiratory gas from the body chamber through the pair of nasal cannula thereby positioning an inflow valve in an OPEN position flowing respiratory gas from the supply tube into the body chamber and thence via the pair of nasal cannula into the nares;
• and
• increasing the chamber pressure within the body chamber to greater than the supply pressure within the supply tube by exhaling an outflow gas through the pair of nasal cannula into the body chamber thereby positioning the inflow valve in a CLOSED position blocking respiratory gas flow from the supply tube into the body chamber.