Methods and apparatus provide automated circuit disconnection monitoring such as for a respiratory apparatus or system. Disconnection of a patient circuit, including a patient interface and air delivery circuit, may be detected and a message or alarm activated. In some versions, detecting occurrences of circuit disconnection event(s), such as by a processor, may be based on an instantaneous disconnection parameter as a function of a disconnection setting. The disconnection setting may be determined based on patient circuit type. The instantaneous disconnection parameter may be determined from detected pressure and flow rate, and may be, for example, a conductance value or an impedance value. Disconnection events may be qualified by one or more detected respiratory indicators. In some cases, instantaneous impedance or conductance may be used to assess re-connection of a patient circuit, detection of flow starvation, determine breath shape for triggering and cycling and to detect patient or circuit obstructions.

A patient interface may include a plenum chamber pressurisable to a therapeutic pressure; a seal-forming structure constructed and arranged to form a seal with a region of the patient's face; a positioning and stabilising structure to provide an elastic force to hold the seal-forming structure on the patient's head, the positioning and stabilising structure may include a tie; a vent structure; a decoupling structure configured to provide a fluid connection between the plenum chamber and an air circuit for the flow of air at the therapeutic pressure for breathing by the patient; and a frame having at least one tie attachment structure to receive the tie, wherein the frame is configured to be resiliently movable in any direction having at least one of a component parallel to the patient's sagittal plane, a component parallel to the patient's coronal plane, a component parallel to the patient's Frankfort horizontal plane.

A pump arrangement for powering a pump in providing a controlled volume of water to a drip nozzle in a drip-feed humidifier. The pump arrangement includes: a pump having a solenoid; a processing unit; and a power supply electrically connected to the solenoid via a switch which is controlled by the processing unit. The power supply is structured to supply power to the solenoid via the switch. The processing unit is programmed to modulate the power provided to the solenoid via the switch such that the power is supplied to the solenoid according to a mirror image power profile for each actuation of the solenoid for retracting the armature. The mirror image power profile includes: an initial portion which decreases at a third overall rate, an intermediate portion which decreases at a second overall rate different than the third overall rate, and a final portion which increases at a first overall rate.

A pump arrangement for powering a pump in providing a controlled volume of water to a drip nozzle in a drip-feed humidifier. The pump arrangement includes: a pump having a solenoid; a processing unit; and a power supply electrically connected to the solenoid via a switch which is controlled by the processing unit. The power supply is structured to supply power to the solenoid via the switch. The processing unit is programmed to modulate the power provided to the solenoid via the switch such that the power is supplied to the solenoid according to a mirror image power profile for each actuation of the solenoid for retracting the armature. The mirror image power profile includes: an initial portion which decreases at a third overall rate, an intermediate portion which decreases at a second overall rate different than the third overall rate, and a final portion which increases at a first overall rate.

A high flow therapy system for delivering heated and humidified respiratory gas to an airway of a patient includes a respiratory gas flow pathway for delivering the respiratory gas to the airway of the patient by way of a non-sealing respiratory interface; wherein flow rate of the respiratory gas is controlled by a microprocessor, a mixing area for mixing a first gas and a second gas in the respiratory gas flow pathway, a humidification area downstream of the mixing area and configured for humidifying respiratory gas in the respiratory gas flow pathway, and a heated delivery conduit for minimizing condensation of humidified respiratory gas.

A high flow therapy system for delivering heated and humidified respiratory gas to an airway of a patient includes a respiratory gas flow pathway for delivering the respiratory gas to the airway of the patient by way of a non-sealing respiratory interface; wherein flow rate of the respiratory gas is controlled by a microprocessor, a mixing area for mixing a first gas and a second gas in the respiratory gas flow pathway, a humidification area downstream of the mixing area and configured for humidifying respiratory gas in the respiratory gas flow pathway, and a heated delivery conduit for minimizing condensation of humidified respiratory gas.

A gas conduit for respiratory apparatus includes a lumen for passage of a breathable gas to a patient and a flexible conduit wall surrounding the lumen. The flexible conduit wall has a humidification apparatus for delivering water vapour into the gas passing through the lumen.

A gas conduit for respiratory apparatus includes a lumen for passage of a breathable gas to a patient and a flexible conduit wall surrounding the lumen. The flexible conduit wall has a humidification apparatus for delivering water vapour into the gas passing through the lumen.

A lightweight impeller is provided for use in a pressurised gas source for a CPAP or other breathing assistance apparatus. The impeller can be shroudless or otherwise lightweight.

Secretions that have accumulated at or near an airway of a subject as the subject is being mechanically ventilated are removed by suctioning. Before, during, and/or after the removal of the secretions, steps are taken to mitigated the impact of the suctioning used for secretion removal on the subject. As such, the timing of suction used to remove secretions may be influenced or controlled, ventilation of the subject during suction may be adjusted, ventilation of the subject prior to secretion removal may be adjusted to prepare the lungs of the subject for secretion removal, ventilation of the subject subsequent to suction for secretion removal may be adjusted, and/or other techniques for reducing the impact of suctioning for secretion removal on the subject may be implemented.