Pressure support system and method and a pressure control valve for use in such a system and method

A pressure support system comprising:

• a pressure generator having an inlet portion and an outlet portion for generating a flow of gas;
• a first conduit having a first end open to ambient atmosphere and a second end coupled to the inlet portion of the pressure generator to supply gas from a gas source to the pressure generator;
• a second conduit having a first end coupled to the outlet portion of the pressure generator and a second end to deliver the flow of gas from the pressure generator to a patient;
• and
• a valve assembly operatively connected to the second conduit to control one of a pressure and a rate of the flow of gas in the second conduit, wherein the valve assembly comprises:
• a first hollow member having an open first end, an open second end, a blower discharge opening defined by at least a portion of a wall thereof, an exhaust intake opening defined by at least a portion of the wall thereof between the blower discharge opening and the second end, and a separating member disposed in the first hollow member between the blower discharge opening and the exhaust intake opening,
• a second hollow member having a first opening defined by at least a portion of a wall thereof, with the second hollow member positioned coaxially around the first hollow member, and
• an actuator associated with the first hollow member and the second hollow member for moving the second hollow member with respect to the first hollow member.