Apparatus and methods provide system characterisation such as for operation of respiratory treatment apparatus. Such a characterisation may include a determination of a patient interface type and/or an event such as a leak or blocked vent. For a characterisation, one or more controller(s) or processor(s) may be configured to make a determination of parameters that best fit a template curve, such as a quadratic function, to a plurality of measurements, such as data points. Each data point may include a pressure value, and a flow rate value at the pressure value. Parameters from the function may then be applied, such as with a data structure to characterize the system, such as with an identification of the patient interface type from the parameters. In some versions, parameter(s) of operation of the apparatus may be adjusted based on the characterisation, such as by using the parameters of the template.

Environmental characteristics of habitable environments (e.g., hotel or motel rooms, spas, resorts, cruise boat cabins, offices, hospitals and/or homes, apartments or residences) are controlled to eliminate, reduce or ameliorate adverse or harmful aspects and introduce, increase or enhance beneficial aspects in order to improve a “wellness” or sense of “wellbeing” provided via the environments. Control of intensity and wavelength distribution of passive and active Illumination addresses various issues, symptoms or syndromes, for instance to maintain a circadian rhythm or cycle, adjust for “jet lag” or season affective disorder, etc. Air quality and attributes are controlled. Scent(s) may be dispersed. Hypoallergenic items (e.g., bedding, linens) may be used. Water quality is controlled. Noise is reduced and sounds (e.g., masking, music, natural) may be provided. Passive and active pathogen controls are employed. Controls are provided for the occupant and/or facility personnel, as is instruction, and surveys, including assessing wellness.

A cannula for providing respiratory therapy to a patient includes a first nasal prong having a proximal end attached to a cannula body and a distal end for insertion into a nare of the patient. The first nasal prong defines a lumen for a flow of breathing gas from a source of breathing gas to the nare of the patient, and the first nasal prong has a variable geometry such that a cross-sectional area of the lumen at the distal end of the first nasal prong varies with a flow rate of the breathing gas. Varying the cross-sectional area of the first nasal prong lumen with the flow rate of the breathing gas enables the first nasal prong to maintain a high velocity flow to the nare for effective flushing of the patient's airway.

A system for providing continuous positive air pressure therapy is provided. The system includes a flow generator, a sensor, and a computing device. The computing device is configured to control operation of the flow generator based on sensor data. The computing device is further configured to display, on a display device, one or more questions relating to demographic and/or subjective feedback; responsive to displaying the one or more questions, receive one or more inputs indicating answers to the one or more questions; transmit the answers to a remote processing system; receive, from the remote processing system, settings determined based on the transmitted answers; and adjust control settings of the system based on the received settings.

An apparatus for humidifying a flow of pressurised, breathable air includes varying a first pressure of the flow of breathable gas to vary a level of thermal engagement between the conductive portion of the reservoir and the heater plate, varying a height of the variable portion varies a level of thermal engagement between the conductive portion of the reservoir and the heater plate, use of a humidifier reservoir base component with a maximum water capacity substantially equal to the predetermined maximum volume of water of the humidifier reservoir or the use of intersecting inlet and outlet axes.

A patient interface for sealed delivery of a flow of air to ameliorate sleep disordered breathing may include: a seal-forming structure to form a pneumatic seal with the entrance to the patient's airways; a positioning and stabilising structure to maintain the seal-forming structure in sealing contact with an area surrounding the entrance to the patient's airways; a plenum chamber pressurised at a pressure above ambient pressure in use; a connection port for the delivery of the flow of breathable gas into the patient interface; and a device positioned within a breathing chamber defined, at least in part, by the seal-forming structure and the plenum chamber, wherein the device divides the breathing chamber into a posterior chamber and an anterior chamber, and wherein the device comprises a plurality of apertures such that turbulence of the air in the posterior chamber is less than turbulence in the air in the anterior chamber.

A pneumatic system for a medical fluid machine operating a medical fluid cassette, the pneumatic system including an interface for supplying positive pneumatic pressure and negative pneumatic pressure to the medical fluid cassette; a source of positive pneumatic pressure; a source of negative pneumatic pressure; and a pneumatic pump including a first head and a second head, wherein the first head is dedicated to supplying positive pneumatic pressure to the positive pneumatic pressure source and the second head is dedicated to supplying negative pneumatic pressure to the negative pneumatic pressure source.

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 flow generator includes a housing, a blower structured to generate a flow of pressurized breathable air, and a suspension device to support the blower within the housing and provide a pressure seal between low and high pressure sides of the blower. The suspension device includes a bellows-like portion provided along the perimeter of the blower to absorb shock applied at least radially to the blower and one or more cones provided along upper and/or lower sides of the blower to absorb shock applied at least axially to the blower.

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.