Abstract: An oxygen system supplies either 100% oxygen to a demand valve in a or pulses of oxygen to the mask. Switching is automatic during a parachute descent. The system includes a valve manifold that is responsive to ambient pressure such that at low pressures it is configured to deliver gas from either an oxygen cylinder or an aircraft supply line to the mask demand valve and at higher pressures it is configured to deliver gas from the cylinder to a pulse gas delivery system. The mask also includes an inhalation valve that is closed if oxygen is supplied to the demand valve. Otherwise, the inhalation valve opens to allow ambient air to be drawn in and the pulse gas delivery system delivers a pulse of oxygen in response to the onset of inhalation.

Abstract: An oxygen system supplies either 100% oxygen to a demand valve in a mask or pulses of oxygen to the mask. Switching is automatic during a parachute descent. The system includes a valve manifold that is responsive to ambient pressure such that at low pressures it is configured to deliver gas from either an oxygen cylinder or an aircraft supply line to the mask demand valve and at higher pressures it is configured to deliver gas from the cylinder to a pulse gas delivery system. The mask also includes an inhalation valve that is closed if oxygen is supplied to the demand valve. Otherwise, the inhalation valve opens to allow ambient air to be drawn in and the pulse gas delivery system delivers a pulse of oxygen in response to the onset of inhalation.

Abstract: A device to assist with the insertion of a nasal bridle includes an insertion guide and an introducer that is attached to bridle tape. The guide is switchable between two configurations: a substantially straight configuration and a second configuration in which an exit aperture at an upper end of the guide is either at a downwardly oriented angle and/or displaced laterally from the guide longitudinal axis, for example by causing the upper end of the guide to adopt a u-bend. The guide is inserted into a nostril while straight and then adopts its second configuration. The introducer is pushed through the guide and, at the exit, is guided beyond the septum into and out of the opposite nostril. Introducer and tape are pulled through the nasal passage before removing the guide. The guide therefore ensures that introducer and tape are held clear of the septum, reducing discomfort.

Abstract: A piston regulator of a type that seals on the low-pressure side of a valve seat (10) includes a mechanism by which the valve can be shut off, for example for transport or storage, without risk of overloading the seat (10). Two exemplary mechanisms are disclosed. The first involves applying a closing load to a regulating piston (6) via a closing piston (17) with a surface that is acted on by secondary pressure to press it away from the regulating piston (6). The second arrangement is based on a nested regulating element: an inner sealing element (901) and outer slidable casing (900) are separable when a closing force is applied. This allows the casing (900) to transfer forces arising from secondary pressure and excessive closing force; the sealing element (901) is pressed onto the seat through a load supplied by a closing spring (903). In both cases, the load on the seat is limited.

Abstract: An oxygen system supplies either 100% oxygen to a demand valve in the a mask or pulses of oxygen to the mask. Switching is automatic during a parachute descent. The system includes a valve manifold that is responsive to ambient pressure such that at low pressures it is configured to deliver gas from either an oxygen cylinder or an aircraft supply line to the mask demand valve and at higher pressures it is configured to deliver gas from the cylinder to a pulse gas delivery system. The mask also includes an inhalation valve that is closed if oxygen is supplied to the demand valve. Otherwise, the inhalation valve opens to allow ambient air to be drawn in and the pulse gas delivery system delivers a pulse of oxygen in response to the onset of inhalation.

Abstract: A piston regulator of a type that seals on the low-pressure side of a valve seat (10) includes a mechanism by which the valve can be shut off, for example for transport or storage, without risk of overloading the seat (10). Two exemplary mechanisms are disclosed. The first involves applying a closing load to a regulating piston (6) via a closing piston (17) with a surface that is acted on by secondary pressure to press it away from the regulating piston (6). The second arrangement is based on a nested regulating element: an inner sealing element (901) and outer slidable casing (900) are separable when a closing force is applied. This allows the casing (900) to transfer forces arising from secondary pressure and excessive closing force; the sealing element (901) is pressed onto the seat through a load supplied by a closing spring (903). In both cases, the load on the seat is limited.

Abstract: A device to assist with the insertion of a nasal bridle includes an elongated insertion guide made of flexible resilient material. The guide includes an exit aperture at its upper end and is switchable between two configurations. In a first configuration, the guide is substantially straight enabling it to be more easily passed into or removed from a nasal cavity. In a second configuration, the exit aperture is either at a downwardly oriented angle and/or displaced laterally from the guide longitudinal direction, for example by causing the upper end of the guide to adopt a u-bend. This enables an introducer, attached to nasal bridle tape, to be passed through the guide and guided beyond the septum and into the opposite nostril. The introducer is then pulled through the nasal passage, with the bridle tape following. The bridle tape may then be used to secure a feeding tube.

Abstract: A gas cylinder valve is opened by application of a pilot gas pressure. The gas cylinder valve connects with a yoke for engaging a valve assembly of a gas cylinder The yoke comprising a pilot gas passage that connects a pilot gas chamber in the cylinder valve assembly to a source of pressurized pilot gas and the cylinder gas port of the gas cylinder valve to an external cylinder gas passage. The valve and yoke enable the gas cylinder to be tamper-resistance.

Abstract: A disc for use in a pneumatic valve includes a stiffening insert encased in a flexible body. The stiffening insert acts to protect a central actuation region of the disc against radial compression, which may arise if the disc is used to seal against a bore hole, and against material flow towards the actuation region away from a clamped periphery. The behavior of the disc in a valve assembly is therefore more predictable and reproducible. The flexible body may further be tensioned across the stiffening insert.

Abstract: A gas cylinder valve is opened by application of a pilot gas pressure. The gas cylinder valve connects with a yoke for engaging a valve assembly of a gas cylinder The yoke comprising a pilot gas passage that connects a pilot gas chamber in the cylinder valve assembly to a source of pressurised pilot gas and the cylinder gas port of the gas cylinder valve to an external cylinder gas passage. The valve and yoke enable the gas cylinder to be tamper-resistance.

Abstract: A gas cylinder valve 2 is able to be opened by application of a pilot gas pressure. In certain embodiments the gas cylinder valve 2 is usable with a yoke 8 for engaging with a valve assembly of a gas cylinder 1, the yoke comprising a pilot gas passage 28 able to connect a pilot gas chamber 37 in the cylinder valve assembly to a source of pressurized pilot gas and the cylinder gas port of the gas cylinder valve to an external cylinder gas passage. The valve and yoke enable the tamper-resistance of a gas cylinder to be improved.

Abstract: A demand valve for gas mixing comprises two or more flow control valves that are connected to separate gas supplies. The demand valve includes a common actuation mechanism, such as a diaphragm arranged to displace levers, each of which, in turn, opens and closes proportionally in a substantially constant ratio a respective flow control valve. Inhalation flow drawn through an outlet causes displacement of the diaphragm and hence opening of the flow control valves. Gas from the separate supplies is therefore mixed in a main chamber to a substantially constant composition, regardless of the flow rate demanded, before being dispensed via the outlet.

Abstract: A gas cylinder valve 2 is able to be opened by application of a pilot gas pressure. In certain embodiments the gas cylinder valve 2 is usable with a yoke 8 for engaging with a valve assembly of a gas cylinder 1, the yoke comprising a pilot gas passage 28 able to connect a pilot gas chamber 37 in the cylinder valve assembly to a source of pressurised pilot gas and the cylinder gas port of the gas cylinder valve to an external cylinder gas passage. The valve and yoke enable the tamper-resistance of a gas cylinder to be improved.

Abstract: A demand valve for gas mixing comprises two or more flow control valves that are connected to separate gas supplies. The demand valve includes a common actuation mechanism, such as a diaphragm arranged to displace levers, each of which, in turn, opens and closes proportionally in a substantially constant ratio a respective flow control valve. Inhalation flow drawn through an outlet causes displacement of the diaphragm and hence opening of the flow control valves. Gas from the separate supplies is therefore mixed in a main chamber to a substantially constant composition, regardless of the flow rate demanded, before being dispensed via the outlet.

Abstract: A disc for use in a pneumatic valve includes a stiffening insert encased in a flexible body. The stiffening insert acts to protect a central actuation region of the disc against radial compression, which may arise if the disc is used to seal against a bore hole, and against material flow towards the actuation region away from a clamped periphery. The behaviour of the disc in a valve assembly is therefore more predictable and reproducible. The flexible body may further be tensioned across the stiffening insert.

Abstract: The nebuliser has a driving gas pathway through a nebulising section and the gas pathway includes a pneumatic control valve operable between an open configuration in which gas is able to flow from a supply inlet through the nebulising section to create an aerosol and to an airway with outlet for onward delivery and a closed configuration in which gas flow to the outlet is stopped. With the nebuliser drugs in an aerosol form can be delivered to a patient during the inhalation phase only and earlier in the inhalation cycle than can be achieved using conventional pneumatically activated nebulisers.