This invention relates to a breath indicator that is receivable by a part of a breathing assistance apparatus that supplies gas to a patient. The indicator comprises an elongate body having a gas sampling end and an attachment end. The attachment end is adapted to attach to a part of a breathing assistance apparatus and for locating the gas sampling end. The gas sampling end is to be located in a region where gas from the patient is to be exhaled. The gas sampling end being in communication with a sensor comprising a detector material changeable between a first visual indicator state relating to an inhalation phase of the patient, and a second visual indicator state relating to an exhalation phase of the patient. The detector material is capable of changing between the visual indicator states at a sufficient rate to substantially correspond with the inhalation and exhalation phases of the patient.

A method of automatically controlling the temperature of a patient circuit (56, 58) of a pressure support system (50) includes determining (directly measuring or estimating/deriving) one or more environmental parameters relating to environmental conditions around the pressure support system, such as ambient temperature and/or ambient humidity, determining a desired temperature based on at least the one or more environmental parameters, and controlling the operation of a heating apparatus (70) operatively associated with the patient circuit based on the desired temperature. Also, a pressure support system implementing the method.

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.

A head-mounted respiratory assistance apparatus configured to provide a respiratory gases stream to a user. The head-mounted respiratory assistance has a main body securable to the head of a user and a blower unit that is operable to generate a pressurized gases stream from a supply of gases from the surrounding atmosphere. A patient interface is provided on the main body that has a gases inlet which is fluidly connected to the blower unit and which is configured to deliver the pressurized gases to the user's nose and/or mouth.

A user interface for respiratory apparatus comprises a combination of a menu display (302), push buttons (304, 308, 310) and a rotary control dial (306). The user interface may include a menu control for detecting at least one parameter from the user's operation of the controls to navigate the menu and applying this to subsequent operation of the user interface controls. The user parameter may be a direction of operation of the rotary control dial which the user associates with a particular direction of navigation within the menu.

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.

A breathing assistance apparatus adapted to deliver humidified gases at a desired level of humidity to a patient including a humidifier and a heated conduit is disclosed. The humidifier includes a controller which controls the humidifier, or the humidifier and the heated conduit to deliver the gases to the patient at the required humidity or temperature, without the requirement for sensors in the gases stream. The controller uses information already available to the controller, without the requirement for additional information to be provided by sensors in the gases stream. This means the need for sensors in the gases stream is dispensed with. A significant benefit is achieved as sensors are not required in the conduit and thus the apparatus is simple and less bulky.

Quantitative colorimetric carbon dioxide measurement and measurement systems and methods are disclosed. The methods can include methods for calibrating a chemical colorimetric indicator used in the quantitative colorimetric carbon dioxide measurement system. Apparatuses are disclosed including a cartridge comprising a chemical colorimetric indicator that is configured to removably engage with a quantitative colorimetric measurement system. Cartridges containing a sealed container comprising a reference gas with a known concentration of carbon dioxide are also disclosed. Systems and methods for humidifying the chemical colorimetric indicator are also provided. Methods for using the systems are also disclosed including providing a breathing therapy to a patient or user.

A patient interface mask for use with a breathing assistance apparatus includes a seal that, in use, circumscribes a nose, mouth, or nose and mouth of a patient and defines an interior space of the mask. The mask includes an inlet into the interior space and an outlet from the interior space. A sensor is positioned outside of the interior space and in the path of exit gases exiting the interior space through the outlet. The sensor detects a parameter of the exit gases, such as temperature, humidity or both.

A breathing circuit for delivering heated, humidified gases to a patient for medical purposes is described, comprising a humidifier chamber holding a quantity of water, a blower unit that delivers a pressurized gases stream to the chamber inlet, and a control system that adjusts output parameters of the breathing circuit, the circuit including a heater plate which heats the water in the chamber so that gases flowing through the chamber become heated and humidified, the circuit also including a gases transportation pathway and patient interface to convey heated humidified gases to a patient, the gases transportation pathway including an RFID tag located at the patient end which senses a parameter of the gases passing through the pathway, the control system including an RFID interrogator interrogating and receiving data relating to the sensed parameter from the RFID tag in real time, and adjusting the output parameters of the breathing circuit accordingly.