A method of estimating a parameter indicative of respiratory flow of a patient being administered flow therapy, comprising: optionally administering a gas at a flow rate to the patient using a flow therapy apparatus with a patient interface, determin—-ing a terminal pressure in, at or proximate the outlet of the patient interface or in, at or proximate the nares of the patient, determin -ing nasal RTF, determining a nasal flow parameter being or indicative of nasal flow based on the pressure and a nasal RTF, and optionally outputting the nasal flow parameter or parameter derived therefrom.

A method of estimating a parameter indicative of respiratory flow of a patient being administered flow therapy, comprising: optionally administering a gas at a flow rate to the patient using a flow therapy apparatus with a patient interface, determin—-ing a terminal pressure in, at or proximate the outlet of the patient interface or in, at or proximate the nares of the patient, determin -ing nasal RTF, determining a nasal flow parameter being or indicative of nasal flow based on the pressure and a nasal RTF, and optionally outputting the nasal flow parameter or parameter derived therefrom.

A system for preventing cross-contamination in single-limb ventilators is described. In one embodiment, the system includes an airflow generator connected in-line to a humidifier, a first check valve and a patient interface by a gas flow circuit. A controller is electrically coupled to the airflow generator, and a cartridge is connected to the gas flow circuit between a first point downstream of the humidifier and a second point upstream of the patient interface. The cartridge includes a bacteria filter and the first check valve. A method for preventing cross-contamination in single-limb ventilators and a method for providing gaseous flow through a single-limb ventilator are also described.

A system for preventing cross-contamination in single-limb ventilators is described. In one embodiment, the system includes an airflow generator connected in-line to a humidifier, a first check valve and a patient interface by a gas flow circuit. A controller is electrically coupled to the airflow generator, and a cartridge is connected to the gas flow circuit between a first point downstream of the humidifier and a second point upstream of the patient interface. The cartridge includes a bacteria filter and the first check valve. A method for preventing cross-contamination in single-limb ventilators and a method for providing gaseous flow through a single-limb ventilator are also described.

A device is provided that humidifies breathing gas. The device has a chamber with an inlet and an outlet. A chemical heater is positioned within the chamber and a trigger activates the heater. The chamber can be a conduit with an inner wall and an outer wall with a reservoir defined therebetween. The chemical heater can be positioned within the reservoir.

A device is provided that humidifies breathing gas. The device has a chamber with an inlet and an outlet. A chemical heater is positioned within the chamber and a trigger activates the heater. The chamber can be a conduit with an inner wall and an outer wall with a reservoir defined therebetween. The chemical heater can be positioned within the reservoir.

A system provides warm, humidified pas to a patient via a patient interface. Horizontal connections can be used between the humidification chamber and conduit. To reduce the likelihood of condensate flowing back to the humidification chamber, or dead space or gases recirculation regions occurring within the gases flow path, a raised portion is positioned inside of the flow path to improve flow characteristics and to provide a barrier for condensate back flow. The raised portion also reduces the amount of condensate that is formed in the system and provides better flow characteristics for sensing purposes.

A system provides warm, humidified pas to a patient via a patient interface. Horizontal connections can be used between the humidification chamber and conduit. To reduce the likelihood of condensate flowing back to the humidification chamber, or dead space or gases recirculation regions occurring within the gases flow path, a raised portion is positioned inside of the flow path to improve flow characteristics and to provide a barrier for condensate back flow. The raised portion also reduces the amount of condensate that is formed in the system and provides better flow characteristics for sensing purposes.

A breathing assistance apparatus has a lid and latch assembly configured for one-handed operation. The apparatus also includes a hinge assembly that separates when over-rotated but that reengages upon closing of the lid onto the main body of the apparatus.

A breathing assistance apparatus has a lid and latch assembly configured for one-handed operation. The apparatus also includes a hinge assembly that separates when over-rotated but that reengages upon closing of the lid onto the main body of the apparatus.