Breathing apparatus

A breathing apparatus comprising:

• a supply tube configured to provide a supply of air;
• a first and second nasal interface fluidly coupled to the supply tube via a housing defining a fluid chamber, the first and second nasal interface each including a generally spherical member having a respective projection configured to be at least partially received within a respective nasal passage of a user, the first and second nasal interface being independently movable relative to the housing;
• a valve disposed between the fluid chamber and an exhaust passage, the valve moveable between a closed position, being engaged with a valve seat, restricting air from being exhausted from the fluid chamber via the exhaust passage, and an open position, being at least partially disengaged with the valve seat, allowing air to be exhausted from the fluid chamber via the exhaust passage, the valve seat including at least one serration extending radially from a valve engagement surface;
• a diaphragm coupled to the valve for moving the valve between the open position and the closed position;
• a bias chamber coupled to the diaphragm for providing a bias force to the diaphragm;
• a loading fluid impedance coupling the fluid chamber with the bias chamber for regulating the bias force based upon, at least in part, a pressure within the fluid chamber;
• and
• a venting fluid impedance coupling the fluid chamber with an ambient environment.

A breathing apparatus comprising:

• a supply tube configured to provide a supply of air;
• a first and second nasal interface fluidly coupled to the supply tube via a housing defining a fluid chamber, the first and second nasal interface each including a generally spherical member having a respective projection configured to be at least partially received within a respective nasal passage of a user, the first and second nasal interface being independently movable relative to the housing;
• a valve disposed between the fluid chamber and an exhaust passage, the valve moveable between a closed position restricting air from being exhausted from the fluid chamber via the exhaust passage, and an open position allowing air to be exhausted from the fluid chamber via the exhaust passage;
• a diaphragm coupled to the valve for moving the valve between the open position and the closed position;
• a bias chamber coupled to the diaphragm for providing a bias force to the diaphragm;
• a loading fluid passage fluidly coupling the bias chamber with a loading fluid source for regulating the bias force;
• and
• a venting fluid impedance coupling the fluid chamber with an ambient environment.