An oscillating positive expiratory pressure apparatus having a housing defining a chamber, a chamber inlet, a chamber outlet, a deformable restrictor member positioned in an exhalation flow path between the chamber inlet and the chamber outlet, and an oscillation member disposed within the chamber. The deformable restrictor member and the oscillation member are moveable between an engaged position, where the oscillation member is in contact with the deformable restrictor member and an disengaged position, where the oscillation member is not in contact with the deformable restrictor member. The deformable restrictor member and the oscillation member move from the engaged position to the disengaged position in response to a first exhalation pressure at the chamber inlet, and move from the disengaged position to an engaged position in response to a second exhalation pressure at the chamber inlet.

A vent valve apparatus (10) for use with a system for supplying breathable gas pressurised above atmospheric pressure to a human or animal. The apparatus (10) includes a gas washout vent (15), a vent valve (18) adapted to progressively restrict the flow area of the washout vent (15), and a pressure sensitive vent valve control means (20,22,23). The control means is adapted to progressively cause the vent valve (18) to restrict the flow area of the gas washout vent (15) in response to increases in the pressure of the gas supply, thereby substantially regulating the volumetric flow of gas and/or CO.sub.2 gas through the washout vent (15) over a range of gas supply pressures.

An oscillating positive expiratory pressure apparatus having a housing defining a chamber, a chamber inlet, a chamber outlet, a deformable restrictor member positioned in an exhalation flow path between the chamber inlet and the chamber outlet, and an oscillation member disposed within the chamber. The deformable restrictor member and the oscillation member are moveable between an engaged position, where the oscillation member is in contact with the deformable restrictor member and an disengaged position, where the oscillation member is not in contact with the deformable restrictor member. The deformable restrictor member and the oscillation member move from the engaged position to the disengaged position in response to a first exhalation pressure at the chamber inlet, and move from the disengaged position to an engaged position in response to a second exhalation pressure at the chamber inlet.

An oscillating positive expiratory pressure apparatus having a housing defining a chamber, a chamber inlet, a chamber outlet, a deformable restrictor member positioned in an exhalation flow path between the chamber inlet and the chamber outlet, and an oscillation member disposed within the chamber. The deformable restrictor member and the oscillation member are moveable between an engaged position, where the oscillation member is in contact with the deformable restrictor member and an disengaged position, where the oscillation member is not in contact with the deformable restrictor member. The deformable restrictor member and the oscillation member move from the engaged position to the disengaged position in response to a first exhalation pressure at the chamber inlet, and move from the disengaged position to an engaged position in response to a second exhalation pressure at the chamber inlet.

An oscillating positive expiratory pressure apparatus having a housing defining a chamber, a chamber inlet, a chamber outlet, a deformable restrictor member positioned in an exhalation flow path between the chamber inlet and the chamber outlet, and an oscillation member disposed within the chamber. The deformable restrictor member and the oscillation member are moveable between an engaged position, where the oscillation member is in contact with the deformable restrictor member and an disengaged position, where the oscillation member is not in contact with the deformable restrictor member. The deformable restrictor member and the oscillation member move from the engaged position to the disengaged position in response to a first exhalation pressure at the chamber inlet, and move from the disengaged position to an engaged position in response to a second exhalation pressure at the chamber inlet.

An oscillating positive expiratory pressure apparatus having a housing defining a chamber, a chamber inlet, a chamber outlet, a deformable restrictor member positioned in an exhalation flow path between the chamber inlet and the chamber outlet, and an oscillation member disposed within the chamber. The deformable restrictor member and the oscillation member are moveable between an engaged position, where the oscillation member is in contact with the deformable restrictor member and an disengaged position, where the oscillation member is not in contact with the deformable restrictor member. The deformable restrictor member and the oscillation member move from the engaged position to the disengaged position in response to a first exhalation pressure at the chamber inlet, and move from the disengaged position to an engaged position in response to a second exhalation pressure at the chamber inlet.

An oscillating positive expiratory pressure apparatus having a housing defining a chamber, a chamber inlet, a chamber outlet, a deformable restrictor member positioned in an exhalation flow path between the chamber inlet and the chamber outlet, and an oscillation member disposed within the chamber. The deformable restrictor member and the oscillation member are moveable between an engaged position, where the oscillation member is in contact with the deformable restrictor member and an disengaged position, where the oscillation member is not in contact with the deformable restrictor member. The deformable restrictor member and the oscillation member move from the engaged position to the disengaged position in response to a first exhalation pressure at the chamber inlet, and move from the disengaged position to an engaged position in response to a second exhalation pressure at the chamber inlet.

The auxiliary breathing flow channel apparatus for an oxygen mask for pilots and crew of an airplane includes a flow control device with closed and open positions to regulate flow through an auxiliary channel. A pressure sensor such as an aneroid capsule automatically closes the auxiliary channel upon a decrease in cabin pressure. A handle also allows a user to manually move the flow regulating means to a closed position.

A gas negative pressure valve is provided which comprises a valve body and a valve cover. A gas inlet and a gas outlet are disposed on the valve body. A drive lever and a diaphragm assembly are disposed inside the valve body, and one end of the drive lever is connected to a lower end of the diaphragm assembly, and the other end of the drive lever is connected with a sealing gasket. An end of the drive lever is hinged on a sidewall of the valve body. A reset spring is disposed between the drive lever and a bottom of an inner chamber of the valve body. A guide passage is opened in the inner chamber of the valve body. An end of the drive lever close to the gas inlet is connected with a guide shaft, a lower end of which is cooperated slidably in the guide passage.