A gas humidifier can have a gas channel comprising an inlet and an outlet. A portion of the gas channel can have a region having a reduction in cross-sectional area relative to the portions of the gas channel outside of the region. A water conduit can extend from the region to a water reservoir. A heating element can heat water entering the region from the water conduit. Water vaporized using the heating element can join the flow of gases passing through the gas channel in use.

The present invention provides for an improved method of determining a water out condition in a humidified gases supply apparatus. The method includes a two step process including a primary determination of a water out condition and a secondary determination of a water out condition. This primary determination is made during observation of the normal operation of the apparatus. During the secondary determination the method takes temporary control over the humidifying part of the apparatus. The secondary determination confirms or contradicts the primary determination.

A drying expiratory limb of a breathing circuit is provided that is configured to increase or optimize drying of a gas to reduce or prevent condensation. The drying expiratory limb can include a wall that is at least partly made of a breathable material configured to allow transmission of water vapor but substantially prevent transmission of liquid water. The wall includes first and second openings in the wall, the openings respectively configured to receive a gas at a first temperature and a first relative humidity and to allow the gas to exit having a second temperature and a second relative humidity. The drying expiratory limb can be configured to tailor the temperature drop of the gas along the wall to maintain a relative humidity within a targeted range and/or to maintain the gas temperature above its dew point temperature.

An apparatus for delivering a flow of gas having: a controller; a housing defining a gas-flow passage flowing a high concentration oxygen gas; a motor with windings, resilient bearing mounts and an impeller to deliver the gas through the gas-flow passage; a flexible printed circuit electrically connecting the motor to the controller and sensor system; and an elastomeric shield to pneumatically isolate the windings from the gas-flow passage.

A method of a control system (2200) controls an inductance motor in a blower including an impeller and volute using a pressure compensation control system. The control system may be implemented in a respiratory pressure therapy device. The control system may include a sensor configured to provide a pressure signal indicative of the pressure of a flow of fluid produced by the blower. A measured pressure may be compared to a set pressure to determine a pressure error. A slip frequency may be adjusted as a function of the pressure error in an attempt to eliminate or minimise the pressure error.

A gas therapy system (1) has a flow line (3, 2), a coupler (6) to a gas source, and an aerosol generator (4) for aerosol delivery, and a patient interface such as a nasal interface (2). A controller (10) is configured to modulate gas flow and aerosol delivery in real time. The controller changes gas flow rate and dynamically reduces aerosol delivery during upper gas flow rates such as 60 LPM, and activates aerosol delivery during lower gas flow rates of for example 10 LPM. The control may also include sensors to detect breathing, so that there is a bias towards increased aerosol delivery during inhalation in addition to during lower level gas flow.

An apparatus for humidification of air to be delivered to a patient's airways may include a reservoir, and a humidifier chamber. The humidifier chamber may include a humidifier wick and a heating element for heating the humidifier chamber. The humidifier wick may comprise a fibrous sheet material. The humidifier chamber and wick may be vertically oriented in use such that a first end of the wick is above the second end of the wick. A deioniser may be provided to deionise the liquid prior to the humidifier wick. The apparatus may pasteurise liquid to be delivered to the humidification wick.

A respiratory therapy system configured to deliver gases to a patient can have a non-sealed gas flow generating arrangement configured to deliver a high flow of positive gas to an airway of a patient and a negative flow of gas away from an airway of the patient. The positive and negative flows of gas can be generated simultaneously. The flow of positive and negative gases reduces exhaled gases in anatomical dead spaces of the patient.

A method, system and apparatus for assessing the coupling between lung perfusion and ventilation in a patient who is mechanically ventilated or who is breathing spontaneously through a conventional artificial airway is provided. Embodiments of the apparatus comprise an adaptor configured to fit between the artificial airway and mechanical ventilator, a measuring chamber in constant fluid communication with the adaptor via one or more measuring chamber sampling ports, and a monitoring unit where data obtained from temperature and relative humidity sensors located in the measuring is calibrated, sampled, logged and analyzed together with anthropometric patient data to display a coupling index Qi and to enable ongoing diagnostic cardio-pulmonary monitoring of a patient by comparing changes in the patient's index during a monitoring interval.

The principles and embodiments of the present invention relate to methods and systems for safely providing NO to a recipient for inhalation therapy. There are many potential safety issues that may arise from using a reactor cartridge that converts NO.sub.2 to NO, including exhaustion of consumable reactants of the cartridge reactor. Accordingly, various embodiments of the present invention provide systems and methods of determining the remaining useful life of a NO2-to-NO reactor cartridge and/or a break-through of NO.sub.2, and providing an indication of the remaining useful life and/or break-through.