Abstract: The invention relates to a method of determining water level in a humidifier chamber that is part of a humidified gases delivery apparatus and system. The method comprising the steps of delivering power to a heater plate, varying the power delivered to the heater plate, measuring the rate of change of temperature and determining the level of water based on the heating characteristics of the volume of water within the chamber, in particular determining the level of water within the chamber based on the rate of change of temperature and the supplied power.

Abstract: A nasal cannula for use in a system for providing a flow of respiratory gases to a user is described. The nasal cannula comprises a body made from a pliable material. The body has an inlet and at least one nasal prong fluidly connected to the inlet. In use a conduit providing a flow of gases to the cannula is connected to the inlet, and the nasal prong is inserted into a user's nostril. The cannula is arranged to direct the flow of gases from the nasal prong towards the front wall of the user's nasal passage within the user's nose.

Abstract: A mask assembly for use as part of an apparatus for supplying a flow of respiratory gases to a user is disclosed. The mask assembly includes a mask body having an inlet through which said flow of respiratory gases are provided to the interior of said mask body. A mask seal assembly comprising a seal of flexible material and a clip of rigid material is attached to the body. The seal has a first side and a second side. The first side of the seal is shaped to approximately match the contours of a user's face and in use substantially seal against a user's face. The second side is attached to the clip. The clip provides an interface extending substantially the full perimeter or periphery of the mask seal assembly for releasably attaching the mask seal assembly to the mask body. The clip comprises a bridging portion spanning outwards from the perimeter or periphery of the mask body to space at least a portion of the second side of the seal outwards from the perimeter or periphery of the mask body.

Abstract: A patient interface has a single loop head strap and a mask for covering at least the nostrils of the user. The single loop head strap extends from the mask at either end. A short length of supple conduit is coupled to the mask by a swivel or ball joint to allow rotation of the conduit relative to the mask through different angles and orientations.

Abstract: A face shield, patient interface and methods of use thereof are described for improved respiratory therapy of patients. In particular, a face shield is disclosed that acts as a seal when used with a patient interface. The face shield may be manufactured from a low melt temperature hard thermoplastic material. The face shield may be formed initially formed to match the general contours of the face, but not customised to a specific user's face. The face shield may be crosslinked to provide shape memory to the seal and to improve its handling properties and is configured to be thermoformed to a user's face. The face shield may be customised to the patient's facial features to a second customised shape.

Abstract: A mask assembly for use as part of an apparatus for supplying a flow of respiratory gases to a user is disclosed. The mask assembly includes a mask body having an inlet through which said flow of respiratory gases are provided to the interior of said mask body. A mask seal assembly comprising a seal of flexible material and a clip of rigid material is attached to the body. The seal has a first side and a second side. The first side of the seal is shaped to approximately match the contours of a user's face and in use substantially seal against a user's face. The second side is attached to the clip. The clip provides an interface extending substantially the full perimeter or periphery of the mask seal assembly for releasably attaching the mask seal assembly to the mask body. The clip comprises a bridging portion spanning outwards from the perimeter or periphery of the mask body to space at least a portion of the second side of the seal outwards from the perimeter or periphery of the mask body.

Abstract: In one embodiment, a nasal cannula is shaped to fit within a user's nares, where the nasal cannula includes at least one prong allowing high flow delivery of humidified gases and creates positive airway pressure in the patient's airway. The prongs have angled ends such that, in use, gases flowing through the prongs are directed to the user's nasal passages. The nasal cannula body is partially swivelling and preferably has a ball joint connector. In another embodiment the nasal cannula may have at least one flared end prong that preferably seals within a patient's nare.

Abstract: A breathing assistance apparatus is designed for use with delivery of respiratory gases to a patient. The breathing assistance apparatus includes a patient interface, having a body section adapted to cover the nose, or nose and mouth of a patient and a sealing interface. The sealing interface includes at least an outer sealing member. The outer sealing member (201) is adapted to attach to the body section in a sealing manner and has a substantially thin section (203) in at least its nasal bridge region. The thin section is substantially thinner than the rest of the outer sealing member.

Abstract: A breathing assistance apparatus is disclosed, for use with delivery of respiratory gases to a patient. The breathing assistance apparatus includes a patient interface, having a body section adapted to cover the nose, or nose and mouth of a patient and a sealing interface. The sealing interface includes at least an outer sealing member. The outer sealing member is adapted to attach to the body section in a sealing manner and has a substantially thin section in at least its nasal bridge region. The thin section is substantially thinner than the rest of the outer sealing member. The patient interface comprises a mask body and a seal assembly. The seal assembly includes a flexible seal, and a rigid seal clip, the seal assembly being removably attached to the mask body via the rigid seal clip. The mask body and rigid seal clip are profiled to match the contours of a user's face so that the seal has a substantially constant wall depth.

Abstract: Headgear for use with a respiratory mask is described. The headgear comprises a continuous and substantially curved elongate member extending in use below a user's nose and at least two headgear straps capable of attachment to the ends of the elongate member. A mask attachment on the elongate member is disposed to sit below or on one of said user's nose, mouth, upper lip and an inlet to the mask. The attachment is capable of receiving the mask.

Abstract: A mask is disclosed that has a gas outlet which is quiet and provides for a diffused outlet flow of gases. The outlet is preferably a slot formed between a hollow body and cover over said hollow body. The mask also preferably extends and seals under a user's chin in use.

Abstract: A breathing assistance apparatus is disclosed, for use with delivery of respiratory gases to a patient. The breathing assistance apparatus includes a patient interface, having a body section adapted to cover the nose, or nose and mouth of a patient and a sealing interface. The sealing interface includes at least an outer sealing member. The outer sealing member is adapted to attach to the body section in a sealing manner and has a substantially thin section in at least its nasal bridge region. The thin section is substantially thinner than the rest of the outer sealing member. The patient interface comprises a mask body and a seal assembly. The seal assembly includes a flexible seal, and a rigid seal clip, the seal assembly being removably attached to the mask body via the rigid seal clip. The mask body and rigid seal clip are profiled to match the contours of a user's face so that the seal has a substantially constant wall depth.

Abstract: A mask assembly for use as part of an apparatus for supplying a flow of respiratory gases to a user is disclosed. The mask assembly includes a mask body having an inlet through which said flow of respiratory gases are provided to the interior of said mask body. A mask seal assembly comprising a seal of flexible material and a clip of rigid material is attached to the body. The seal has a first side and a second side. The first side of the seal is shaped to approximately match the contours of a user's face and in use substantially seal against a user's face. The second side is attached to the clip. The clip provides an interface extending substantially the full perimeter or periphery of the mask seal assembly for releasably attaching the mask seal assembly to the mask body. The clip comprises a bridging portion spanning outwards from the perimeter or periphery of the mask body to space at least a portion of the second side of the seal outwards from the perimeter or periphery of the mask body.

Abstract: A breathing assistance apparatus is disclosed, for use with delivery of respiratory gases to a patient. The breathing assistance apparatus includes a patient interface, having a body section adapted to cover the nose, or nose and mouth of a patient and a sealing interface. The sealing interface includes at least an outer sealing member. The outer sealing member is adapted to attach to the body section in a sealing manner and has a substantially thin section in at least its nasal bridge region. The thin section is substantially thinner than the rest of the outer sealing member. The patient interface comprises a mask body and a seal assembly. The seal assembly includes a flexible seal, and a rigid seal clip, the seal assembly being removably attached to the mask body via the rigid seal clip. The mask body and rigid seal clip are profiled to match the contours of a user's face so that the seal has a substantially constant wall depth.

Abstract: A breathing assistance apparatus is disclosed, for use with delivery of respiratory gases to a patient. The breathing assistance apparatus includes a patient interface, having a body section adapted to cover the nose, or nose and mouth of a patient and a sealing interface. The sealing interface includes at least an outer sealing member. The outer sealing member is adapted to attach to the body section in a sealing manner and has a substantially thin section in at least its nasal bridge region. The thin section is substantially thinner than the rest of the outer sealing member. The patient interface comprises a mask body and a seal assembly. The seal assembly includes a flexible seal, and a rigid seal clip, the seal assembly being removably attached to the mask body via the rigid seal clip. The mask body and rigid seal clip are profiled to match the contours of a user's face so that the seal has a substantially constant wall depth.

Abstract: A sealing interface forms part of an apparatus for supplying a flow of respiratory gases to a user. The sealing interface comprises a foam or gel inner cushion and a thin resilient rubber outer sheath. A face side of the inner cushion resiliently supports the outer sheath. The inner cushion has a toothed profile formed on the face side of the inner cushion. The toothed profile consists of at least one tooth having an apex on the perimeter of the inner cushion. The apex is positioned between two valleys in the perimeter of the inner cushion. In use the apex of each tooth of the toothed profile is in supporting contact with the outer sheath.

Abstract: A mask assembly for use as part of an apparatus for supplying a flow of respiratory gases to a user is disclosed. The mask assembly includes a mask body having an inlet through which said flow of respiratory gases are provided to the interior of said mask body. A mask seal assembly comprising a seal of flexible material and a clip of rigid material is attached to the body. The seal has a first side and a second side. The first side of the seal is shaped to approximately match the contours of a user's face and in use substantially seal against a user's face. The second side is attached to the clip. The clip provides an interface extending substantially the full perimeter or periphery of the mask seal assembly for releasably attaching the mask seal assembly to the mask body. The clip comprises a bridging portion spanning outwards from the perimeter or periphery of the mask body to space at least a portion of the second side of the seal outwards from the perimeter or periphery of the mask body.

Abstract: A mask with cushion that has an outer film is disclosed. The film may be self-skinning or a film formed about or glued to the cushion body. In another form the cushion may be formed with at least a portion having a plurality of adjacent voids having honeycomb-like structure.

Abstract: Headgear for use with a respiratory mask is described. The headgear comprises a continuous and substantially curved elongate member extending in use below a user's nose and at least two headgear straps capable of attachment to the ends of the elongate member. A mask attachment on the elongate member is disposed to sit below or on one of said user's nose, mouth, upper lip and an inlet to the mask. The attachment is capable of receiving the mask.

Abstract: In one embodiment, a nasal cannula is shaped to fit within a user's nares, where the nasal cannula includes at least one prong allowing high flow delivery of humidified gases and creates positive airway pressure in the patient's airway. The prongs have angled ends such that, in use, gases flowing through the prongs are directed to the user's nasal passages. The nasal cannula body is partially swivelling and preferably has a ball joint connector. In another embodiment the nasal cannula may have at least one flared end prong that preferably seals within a patient's nare.