Respiratory therapy apparatuses with improved modes of operation

Abstract

A respiratory apparatus configured to provide a flow of gases to a user for respiratory therapy, comprising: a flow generator configured to generate the flow of gases for the user; and a humidifier comprising a heater plate configured to humidify the flow of gases. The apparatus is configured to selectively operate in a therapy mode or one of a plurality of non-therapy modes, the non-therapy modes comprising at least a drying mode and a gas safety mode.

Description

[0001] RESPIRATORY THERAPY APPARATUSES WITH IMPROVED MODES OF OPERATION

[0002] FIELD OF THE DISCLOSURE

[0003] This disclosure relates to respiratory therapy apparatuses, particularly to respiratory therapy apparatuses with improved modes of operation, including safety improvements for them.

[0004] BACKGROUND

[0005] Breathing assistance apparatuses deliver a flow of gases to users or patients in various environments, such as hospitals, medical facilities, residential care, or home environments. In a home environment, a patient is a naive user due to a lack of experience and, therefore, a breathing assistance apparatus operated in a homecare environment requires more safety features and easier use than in environments with trained users.

[0006] A breathing assistance or respiratory therapy apparatus (collectively, “respiratory apparatus”) may deliver supplementary oxygen or other gases with a flow of gases to the patient and / or contain a humidification apparatus to deliver heated and humidified gases. A respiratory apparatus may allow adjustment and control over characteristics of the gases flow, including flow rate, temperature, gases concentration, humidity, pressure, etc. Sensors, such as flow sensors and / or pressure sensors, are used to measure the characteristics of the gases flow.

[0007] High flow therapy provides a high gases flow rate (e.g., above 15 L / min) with high humidity (e.g., generally a body temperature dew point of 37 degrees Celsius or 44 mg of absolute humidity) to the patient via an unsealed nasal cannula. Humidity is required for the comfort of high flow therapy users. High flow therapy provides supplementary oxygen to benefit patients suffering from respiratory conditions, in particular patients suffering from breathlessness. High flow therapy also flushes carbon dioxide from the upper airways and increases the oxygen fraction of the patient. The duration of the therapy depends on the underlying disease. Patients suffering from chronic respiratory disease e.g., Chronic Obstructive Pulmonary Disease (COPD), emphysema or chronic bronchitis, or bronchiectasis, are treated at home using high flow therapy.

[0008] A high flow of heated, humidified gases often causes condensation on the inner surfaces of the breathing conduit or tube after therapy has ended. This accumulated condensation can harbour pathogens or promote microbial growth. Consequently, maintaining the hygiene of the breathing conduit is important in reducing the risk of the patient being infected due to microbe growth. However, cleaning the breathing conduit after therapy is time-consuming and may not always be done thoroughly in a home environment.

[0009] Several methods are known in the art for removing condensation from a breathing conduit. For example, International Patent Application No. PCT / NZ2006 / 000132 (Fisher & Paykel Healthcare Limited) discloses a breathing assistance apparatus with a drying mode or cycle to dry the tubing that supplies gases to a user and, thereby, prevent the harbouring of pathogens within the tube. The drying mode automatically starts when the therapy is finished and involves providing a constant gases flow rate through a tube containing heater wires to heat the tube. During the drying mode, the heater plate for heating the chamber of the humidifier is turned off, but full power is maintained to the heater wires in the tube for a predetermined time. However, this drying mode can take a long time to sufficiently dry the tube, e.g., 60-90 minutes, during which the user cannot receive therapy. Additionally, despite the heater plate being off during this time, the heater plate and the humidification chamber can still be quite hot at the end of the drying mode, as during a therapy session, the heater plate can be heated to high temperatures. This situation presents a bum risk if either the heater plate or the humidification is touched (e.g., when trying to remove the chamber from the heater plate after therapy for cleaning), especially in a home environment, since no technicians or nurses are available to assist the patient. A fire risk can be produced by the user forgetting to switch off the oxygen supply to the respiratory apparatus after a therapy session, e.g., during a drying mode. This is especially common when nasal high flow (NHF) therapy is provided in a home environment. A respiratory apparatus configured for NHF therapy typically has one or two oxygen inlets (one for low-pressure oxygen and the other for high-pressure oxygen) for connection to an oxygen concentrator or, less commonly, an oxygen gas bottle so that the patient can be provided with supplementary oxygen with the gases flow. During a drying mode, the patient is instructed not to wear the unsealed nasal cannula worn during NHF therapy. Accordingly, if the oxygen supply is not switched off during drying mode, oxygen will continue to pass through the NHF device and spill into a room. As well as creating a fire risk in the room, the wasted oxygen also results in wasted money, as oxygen is typically expensive to purchase. Additionally, the continual operation of the oxygen concentrator can cause it to be overworked and stop working.

[0010] SUMMARY

[0011] The present disclosure broadly comprises a respiratory apparatus configured to provide a flow of gases to a user for respiratory therapy, comprising: a flow generator configured to generate the flow of gases for the user; and a humidifier comprising a heater plate configured to humidify the flow of gases; wherein the apparatus is configured to selectively operate in a therapy mode or one of a plurality of non-therapy modes.

[0012] In a configuration, the non-therapy modes comprise at least a drying mode and a gas safety mode; and the apparatus comprises a controller, wherein the controller is configured to: selectively either: operate the flow generator at a therapy flow rate and operate the heater plate at one or more therapy power levels to provide a humidified flow of gases along a gases flow path to the user for respiratory therapy, when the apparatus is operated in the therapy mode; or operate the flow generator according to a drying flow rate and / or the heater plate at no power or to a controller power level to dry at least a portion of the gases flow path, when the apparatus is operated in the drying mode; receive or determine oxygen concentration data indicative or representative of a concentration of oxygen in the flow of gases; compare the oxygen concentration data to one or more safety thresholds when the apparatus is operated in or transitioning to the drying mode; and switch operation of the apparatus to the gas safety mode or shut off an oxygen supply based on the comparison indicating that the concentration of oxygen in the flow of gases to the user exceeds one or more of the safety thresholds.

[0013] In a configuration, the one or more safety thresholds comprise a pre-set value against which the oxygen concentration data is compared.

[0014] In a configuration, the one or more safety thresholds comprise a time-based threshold.

[0015] In a configuration, the comparison comprises assessing the oxygen concentration data against the one or more safety thresholds for a time-based threshold.

[0016] In a configuration, the controller is configured to switch operation of the apparatus to the gas safety mode or shut off an oxygen supply based on the comparison indicating that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds continuously for a predetermined duration.

[0017] In a configuration, the apparatus includes one or more ultrasound or ultrasonic gas concentration sensors configured to generate the oxygen concentration data or information for use in deducing the oxygen concentration data.

[0018] In a configuration, the information for use in deducing the oxygen concentration data comprises one or more measurements of characteristics of the flow of gases.

[0019] In a configuration, the one or more measurements comprise the change in the wavelength of sound through the flow of gases. In a configuration, the one or more measurements comprise a rate of the flow of gases and a rate of a flow of oxygen into the flow of gases.

[0020] In a configuration, the one or more sensors are configured to measure a flow rate of the flow of gases and a flow rate of supplemental oxygen provided into the gases flow path.

[0021] In a configuration, the one or more sensors are positioned in line with the flow of gases.

[0022] In a configuration, the controller power level is a low power level such that no more than a negligible portion of the flow of gases along the gases flow path to the user is humidified.

[0023] In a configuration, the apparatus is connectable to or further comprises a heatable breathing conduit that forms part of the gases flow path for conveying the humidified flow of gases to the user.

[0024] In a configuration, the heatable breathing conduit comprises a first end that is connected or connectable to a gases outlet of the respiratory apparatus and a second end that is connected or connectable to a patient interface.

[0025] In a configuration, the patient interface includes one or more patient detection sensors configured to monitor the connection status of the user to the patient interface.

[0026] In a configuration, the controller is configured to receive or determine connection status data from the one or more patient detection sensors, the connection status data being indicative or representative of the connection status of the user to the patient interface. In a configuration, the controller is configured to stop the drying mode or prevent the drying mode from being activated if the controller determines from the connection status data that the user is not connected to the patient interface.

[0027] In a configuration, the heatable breathing conduit includes one or more heater wires that are configured to heat at least a portion of the breathing conduit and the flow of gases conveyed by the breathing conduit based on the controller power applied to the one or more heater wires.

[0028] In a configuration, when the apparatus is operated in the drying mode, the controller is configured to provide full power or substantially full or high power to the one or more heater wires such that at least a substantial portion of the flow of gases within the heatable breathing conduit is dried.

[0029] In a configuration, when the apparatus is operated in the drying mode, the controller is configured to provide full power or substantially full or high power to the one or more heater wires to heat any liquid in the breathing conduit.

[0030] In a configuration, the heatable breathing conduit includes one or more temperature sensors for measuring a temperature of the flow of gases and the power provided to the heater wire is sufficient to increase the temperature of the heater wire to be above the temperature measured by the one or more temperature sensors.

[0031] In a configuration, the power provided to the heater wire is a predefined power profile.

[0032] In a configuration, the controller is configured to automatically operate the apparatus in the drying mode at the conclusion of the therapy mode. In a configuration, the controller is configured to operate the apparatus in the drying mode based on user input relating to the manual initiation of the drying mode after the conclusion of the therapy mode.

[0033] In a configuration, the user input relating to the manual initiation of the drying mode is received via a user interface.

[0034] In a configuration, the controller is configured to continue to operate the apparatus in the drying mode while the comparison indicates that the concentration of oxygen in the flow of gases does not exceed the one or more of the safety thresholds.

[0035] In a configuration, the controller is configured to continue to operate the apparatus in the drying mode for a predetermined duration.

[0036] In a configuration, the controller is configured to operate the flow generator according to two or more drying flow rates when the apparatus is operated in the drying mode.

[0037] In a configuration, the controller is configured to control the drying flow rate according to one or more predetermined profiles or functions when operating in the drying mode.

[0038] In a configuration, the or each drying flow rate is less than the therapy flow rate.

[0039] In a configuration, the or each drying flow rate is greater than the therapy flow rate.

[0040] In a configuration, the drying flow rate is consistently the maximum flow rate that can be produced by the apparatus.

[0041] In a configuration, the controller is configured to supply no power to the heater plate and maximum power to a heater wire(s) in a heatable breathing conduit. In a configuration, the controller is configured to receive or determine humidifier temperature data indicative or representative of a temperature of or relating to the humidifier, compare the humidifier temperature data to one or more safety thresholds when the apparatus is operated in the drying mode, and end the drying mode based on the comparison indicating that the temperature of or relating to the humidifier is less than one or more of the safety thresholds.

[0042] In a configuration, the controller is configured to end the drying mode based on the comparison indicating that the temperature of or relating to the humidifier is continuously less than one or more of the safety thresholds for a predetermined duration.

[0043] In a configuration, the apparatus includes one or more sensors configured to generate the humidifier temperature data or information for use in deducing the humidifier temperature data.

[0044] In a configuration, the temperature of the heater plate is measured as an indication of the temperature of the humidifier.

[0045] In a configuration, the drying flow rate comprises a constant rate of between 10 to 16 L / min.

[0046] In a configuration, the controller is configured to supply a set power level to a heater wire(s) in a heatable breathing conduit, and the drying flow rate is proportionally modulated in response to the temperature of the heater plate.

[0047] In a configuration, the controller is configured to receive or determine ambient noise data indicative or representative of noise produced by the apparatus, compare the ambient noise data to one or more noise thresholds when the apparatus is operated in the drying mode, and decrease the drying flow rate based on the comparison indicating that the noise produced by the apparatus is greater than one or more of the noise thresholds. In a configuration, the apparatus includes one or more sensors configured to generate the ambient noise data or information for use in deducing the ambient noise data.

[0048] In a configuration, the drying flow rate decreases over time.

[0049] In a configuration, the drying flow rate decreases over time at a rate proportional to the decreasing temperature of the heater plate.

[0050] In a configuration, the controller is configured to stop the drying mode if any one of the following occurs: (a) the drying mode has run for a predetermined duration; (b) the power supplied to heater wire(s) within a heatable breathing conduit follows a predefined power curve; and (c) a heating rate of the heater plate is greater than a threshold value.

[0051] In a configuration, the controller is configured to monitor the power supplied to a heater wire(s) within a heatable breathing conduit and determine whether the power aligns with a predefined power curve as an indicator of whether the conduit contains moisture.

[0052] In a configuration, the controller is configured to receive or determine humidifier temperature data indicative or representative of a temperature of or relating to the humidifier, compare the humidifier temperature data to one or more safety thresholds when the apparatus is operated in the drying mode, and adjust the drying flow rate based on the comparison indicating that the temperature of or relating to the humidifier is less than one or more of the safety thresholds.

[0053] In a configuration, the controller is configured to adjust the drying flow rate based on the comparison indicating that the temperature of or relating to the humidifier is continuously less than one or more of the safety thresholds for a predetermined duration. In a configuration, the apparatus includes one or more sensors configured to generate the humidifier temperature data or information for use in deducing the humidifier temperature data.

[0054] In a configuration, the temperature of the heater plate is measured as an indication of the temperature of the humidifier.

[0055] In a configuration, the controller is configured to carry out one or more moisture checks to detect the presence of moisture in a breathing conduit.

[0056] In a configuration, the or at least one moisture check is carried out during the drying mode.

[0057] In a configuration, the controller is configured to: a) retrieve at least one first signal associated with or indicative of a gases flow and / or pressure in the breathing conduit; b) determine a measure of at least one first parameter associated with gases flow perturbations and / or pressure perturbations for at least one portion of the retrieved at least one first signal; and c) determine the presence of liquid in the breathing conduit based at least in part on the measure(s) of the at least one first parameter meeting a first threshold.

[0058] In a configuration, the controller is configured to operate the drying mode until there is no, or low, moisture detected.

[0059] In a configuration, the perturbation signal is compared with a threshold to determine the presence of liquid.

[0060] In a configuration, the controller is configured to carry out a frequency analysis on the perturbations to detect the presence of liquid in the breathing conduit. In a configuration, the or at least one moisture check comprises monitoring the temperature of the heater plate and the input power needed to maintain a set temperature of the heater plate, thereby determining whether the temperature of the heater plate aligns with a power curve.

[0061] In a configuration, the or at least one moisture check comprises monitoring the temperature of the heater plate while the heater plate provides a short heat pulse and / or monitoring the temperature of any heatable breathing conduit while heater wire(s) within the conduit provide a short heat pulse.

[0062] In a configuration, when the apparatus is operated in the gas safety mode, the controller is configured to provide no power or low power to the heater wire.

[0063] In a configuration, when the apparatus is operated in the gas safety mode, the controller is configured to provide no power or low power to the heater plate.

[0064] In a configuration, the apparatus is configured to be operationally connected to at least one source of oxygen for blending with the flow of gases.

[0065] In a configuration, the or at least one of the sources of oxygen is connected to the apparatus via a controllable valve, the controllable valve configured to control the flow rate of oxygen entering the apparatus from the oxygen source.

[0066] In a configuration, the controller is configured to control the controllable valve to prevent oxygen from entering the apparatus from the oxygen source when operating in the gas safety mode.

[0067] In a configuration, the controller is configured to automatically close the controllable valve based on the comparison indicating that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds. In a configuration, the controller is configured to prompt the user to manually close the controllable valve or otherwise switch off the supply from the or each source of oxygen when the comparison indicates that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds.

[0068] In a configuration, when the apparatus is operated in the gas safety mode, the controller is configured to trigger or generate an alert, alarm, and / or notification based at least partly on determining that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds.

[0069] In a configuration, the controller is configured to generate the alert, alarm, and / or notification in a form selected from any one or more of the following: audible, visual, and / or tactile.

[0070] In a configuration, the apparatus further comprises an audio output device in electrical communication with the controller, and wherein the controller is configured to generate the alert, alarm, and / or notification audibly via the audio output device.

[0071] In a configuration, the apparatus further comprises a display screen in electrical communication with the controller, and wherein the controller is configured to generate the alert, alarm, and / or notification visually via the display screen.

[0072] In a configuration, the controller is configured to send or transmit data representing the alert, alarm, and / or notification to a remote device or system that is in data communication with the apparatus.

[0073] In a configuration, when the apparatus is operated in the gas safety mode, the controller is configured to operate the flow generator at a flushing flow rate to flush the gases flow path. In a configuration, the flushing flow rate is configured to flush any supplemental oxygen from the gases flow path of the apparatus.

[0074] In a configuration, the flushing flow rate is at least 10 L / min.

[0075] In a configuration, the flushing flow rate is at least 15 L / min.

[0076] In a configuration, the controller is configured to operate the flow generator at two or more flushing flow rates during the gas safety mode.

[0077] In a configuration, the controller is configured to operate the flow generator at the or each flushing flow rate automatically based on the comparison indicating that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds.

[0078] In a configuration, the controller is configured to operate the flow generator at the or each flushing flow rate based on user input relating to the manual initiation of a flushing flow.

[0079] In a configuration, the user input relating to the manual initiation of the flushing flow is received via a user interface.

[0080] In a configuration, the controller is configured to operate the flow generator at the or each flushing flow rate for a predetermined duration.

[0081] In a configuration, the controller is configured to operate the flow generator at the or each flushing flow rate until the concentration of oxygen in the flow of gases is less than or equal to one or more of the safety thresholds.

[0082] In a configuration, the plurality of non-therapy modes includes a standby mode. In a configuration, the plurality of non-therapy modes includes a disinfection mode.

[0083] In a configuration, when the apparatus is operated in the disinfection mode, the controller is configured to operate the flow generator at a flushing flow rate to flush the gases flow path.

[0084] In a configuration, the flushing flow rate is configured to flush any supplemental oxygen from the gases flow path of the apparatus.

[0085] In a configuration, the flushing flow rate is at least 10 L / min.

[0086] In a configuration, the flushing flow rate is at least 15 L / min.

[0087] In a configuration, the controller is configured to operate the flow generator at two or more flushing flow rates during the disinfection mode.

[0088] In a configuration, the controller is configured to operate the flow generator at the or each flushing flow rate automatically based on the comparison indicating that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds.

[0089] In a configuration, the controller is configured to operate the flow generator at the or each flushing flow rate based on user input relating to the manual initiation of a flushing flow.

[0090] In a configuration, the user interface relating to the manual initiation of the flushing flow is received via a user interface.

[0091] In a configuration, the controller is configured to operate the flow generator at the or each flushing flow rate for a predetermined duration. In a configuration, the controller is configured to operate the flow generator at the or each flushing flow rate until the concentration of oxygen in the flow of gases is less than or equal to one or more of the safety thresholds.

[0092] In a configuration, the heater plate is controlled to no power or low power when the flow generator is operated at the flushing flow rate.

[0093] In a configuration, the or any heater wire(s) of the or any heatable breathing conduit are controlled to no power or low power when the flow generator is operated at the flushing flow rate.

[0094] In a configuration, the plurality of non-therapy modes includes a cooling mode.

[0095] In a configuration, the controller is configured to further selectively operate the flow generator at one or more cooling flow rates and / or the heater plate to a controlled power level to cool at least a portion of the gases flow path.

[0096] In a configuration, the controller is configured to: compare the oxygen concentration data to one or more safety thresholds when the apparatus is operated in or transitioning to the cooling mode; and switch operation of the apparatus to the gas safety mode or shut off an oxygen supply based on the comparison indicating that the concentration of oxygen in the flow of gases to the user exceeds one or more of the safety thresholds.

[0097] In a configuration, the one or more safety thresholds comprise a pre-set value against which the oxygen concentration data is compared.

[0098] In a configuration, the one or more safety thresholds comprise a time-based threshold.

[0099] In a configuration, the comparison comprises assessing the oxygen concentration data against the one or more safety thresholds for a time-based threshold. In a configuration, the heater plate is controlled to no power or low power during the cooling mode.

[0100] In a configuration, the or any heater wire(s) of the or any heatable breathing conduit are controlled to no power or low power during the cooling mode.

[0101] In a configuration, the non-therapy modes comprise at least a cooling mode and a drying mode; and the apparatus comprises a controller, wherein the controller is configured to: selectively either: operate the flow generator at a therapy flow rate and operate the heater plate at one or more therapy power levels to provide a humidified flow of gases along a gases flow path to the user for respiratory therapy, when the apparatus is operated in the therapy mode; operate the flow generator according to a cooling flow rate and / or the heater plate to a controlled power level to cool at least a portion of the gases flow path, when the apparatus is operated in the cooling mode; or operate the flow generator according to a drying flow rate and / or the heater plate at no power or to a controller power level to dry at least a portion of the gases flow path, when the apparatus is operated in the drying mode; detect the conclusion of the therapy mode and operate the apparatus in the cooling mode at the detected conclusion of the therapy mode to cool the heater plate and / or other components of the humidifier; and switch operation of the apparatus to the drying mode.

[0102] In a configuration, the controller is configured to operate the apparatus in the drying mode after operating the apparatus in the cooling mode and / or at the conclusion of the cooling mode.

[0103] In a configuration, the controller is configured to switch operation of the apparatus to the drying mode after a predetermined duration. In a configuration, the controller is configured to receive or determine humidifier temperature data indicative or representative of a temperature of or relating to the humidifier, compare the humidifier temperature data to one or more safety thresholds when the apparatus is operated in the therapy mode, and switch operation of the apparatus to the cooling mode based on the comparison indicating that the temperature of or relating to the humidifier is greater than one or more of the safety thresholds.

[0104] In a configuration, the controller is configured to switch operation of the apparatus to the cooling mode based on the comparison indicating that the temperature of or relating to the humidifier is continuously greater than one or more of the safety thresholds for a predetermined duration.

[0105] In a configuration, the controller is configured to receive or determine humidifier temperature data indicative or representative of a temperature of or relating to the humidifier, compare the humidifier temperature data to one or more safety thresholds when the apparatus is operated in the therapy mode or operated in or transitioning to the cooling mode, and switch operation of the apparatus to the drying mode based on the comparison indicating that the temperature of or relating to the humidifier is less than one or more of the safety thresholds.

[0106] In a configuration, the controller is configured to switch operation of the apparatus to the drying mode after operating the apparatus in the cooling mode and / or at the conclusion of the cooling mode.

[0107] In a configuration, the controller is configured to switch operation of the apparatus to the drying mode based on the comparison indicating that the temperature of or relating to the humidifier is continuously less than one or more of the safety thresholds for a predetermined duration. In a configuration, the apparatus includes one or more sensors configured to generate the humidifier temperature data or information for use in deducing the humidifier temperature data.

[0108] In a configuration, the temperature of the heater plate is measured as an indication of the temperature of the humidifier.

[0109] In a configuration, the controller is configured to operate the apparatus in the cooling mode after operating the apparatus in the drying mode and / or at the conclusion of the drying mode.

[0110] In a configuration, the heater plate is controlled to no power or low power during the cooling mode.

[0111] In a configuration, the apparatus is connectable to or further comprises a heatable breathing conduit that forms part of the gases flow path for conveying the humidified flow of gases to the user.

[0112] In a configuration, the heatable breathing conduit comprises a first end that is connected or connectable to a gases outlet of the respiratory apparatus and a second end that is connected or connectable to a patient interface.

[0113] In a configuration, the patient interface includes one or more patient detection sensors configured to monitor the connection status of the user to the patient interface.

[0114] In a configuration, the controller is configured to receive or determine connection status data from the one or more patient detection sensors, the connection status data being indicative or representative of the connection status of the user to the patient interface. In a configuration, the controller is configured to stop the drying mode or prevent the drying mode from being activated if the controller determines from the connection status data that the user is not connected to the patient interface.

[0115] In a configuration, the second end of the breathing conduit includes one or more temperature sensors and the controller is configured to operate the apparatus in the cooling mode after operating the apparatus in the drying mode and / or at the conclusion of the drying mode until the measured temperature at the second end of the breathing conduit is less than ambient temperature or less than 25 degrees Celsius.

[0116] In a configuration, the heatable breathing conduit comprises one or more heater wires that are configured to heat at least a portion of the breathing conduit and the flow of gases conveyed by the breathing conduit based on the controller power applied to the one or more heater wires.

[0117] In a configuration, the heater wire(s) of the heatable breathing conduit are controlled to no power or low power during the cooling mode.

[0118] In a configuration, the power provided to the heater wire(s) is sufficient to ensure that the second end of the breathing conduit is maintained at a predetermined temperature.

[0119] In a configuration, the power provided to the heater wire(s) is a predefined power profile.

[0120] In a configuration, the first end of the breathing conduit is connected to a gases outlet of a chamber of the humidifier and the power provided to the heater wire is sufficient to ensure that the temperature at the second end of the breathing conduit is 1 to 5 degrees Celsius greater than the temperature at the gases outlet of the chamber.

[0121] In a configuration, the gases outlet of the chamber and the second end of the breathing conduit both contain one or more temperature sensors. In a configuration, the controller is configured to variably determine the cooling flow rate based on humidifier temperature data and one or more determined ambient temperatures.

[0122] In a configuration, the controller is configured to operate the flow generator at the cooling flow rate for a predetermined duration.

[0123] In a configuration, the cooling flow rate is greater than or equal to the therapy flow rate.

[0124] In a configuration, the cooling flow rate is based on a maximum speed of a motor of the flow generator.

[0125] In a configuration, the controller is configured to detect the conclusion of the therapy mode based on user input relating to the manual termination of the therapy mode or on a disconnection of a patient interface for a predetermined duration.

[0126] In a configuration, the controller power level is a low power level such that no more than a negligible portion of the flow of gases along the gases flow path to the user is humidified.

[0127] In a configuration, when the apparatus is operated in the drying mode, the controller is configured to provide full power or substantially full or high power to the heater wire(s) such that at least a substantial portion of the flow of gases within the breathing conduit is dried.

[0128] In a configuration, when the apparatus is operated in the drying mode, the controller is configured to provide full power or substantially full or high power to the heater wire(s) to heat any liquid in the breathing conduit. In a configuration, the controller is configured to operate the flow generator according to two or more drying flow rates when the apparatus is operated in the drying mode.

[0129] In a configuration, the controller is configured to control the drying flow rate according to one or more predetermined profiles or functions when operating in the drying mode.

[0130] In a configuration, the or each drying flow rate is less than the therapy flow rate.

[0131] In a configuration, the or each drying flow rate is greater than the therapy flow rate.

[0132] In a configuration, the drying flow rate is consistently the maximum flow rate that can be produced by the apparatus.

[0133] In a configuration, the controller is configured to supply no power to the heater plate and maximum power to a heater wire(s) in a heatable breathing conduit.

[0134] In a configuration, the controller is configured to receive or determine humidifier temperature data indicative or representative of a temperature of or relating to the humidifier, compare the humidifier temperature data to one or more safety thresholds when the apparatus is operated in the drying mode, and end the drying mode based on the comparison indicating that the temperature of or relating to the humidifier is less than one or more of the safety thresholds.

[0135] In a configuration, the controller is configured to end the drying mode based on the comparison indicating that the temperature of or relating to the humidifier is continuously less than one or more of the safety thresholds for a predetermined duration.

[0136] In a configuration, the apparatus includes one or more sensors configured to generate the humidifier temperature data or information for use in deducing the humidifier temperature data. In a configuration, the temperature of the heater plate is measured as an indication of the temperature of the humidifier.

[0137] In a configuration, the drying flow rate comprises a constant rate of between 10 to 16 L / min.

[0138] In a configuration, the controller is configured to supply a set power level to a heater wire(s) in a heatable breathing conduit, and the drying flow rate is proportionally modulated in response to the temperature of the heater plate.

[0139] In a configuration, the controller is configured to receive or determine ambient noise data indicative or representative of noise produced by the apparatus, compare the ambient noise data to one or more noise thresholds when the apparatus is operated in the drying mode, and decrease the drying flow rate based on the comparison indicating that the noise produced by the apparatus is greater than one or more of the noise thresholds.

[0140] In a configuration, the apparatus includes one or more sensors configured to generate the ambient noise data or information for use in deducing the ambient noise data.

[0141] In a configuration, the drying flow rate decreases over time.

[0142] In a configuration, the drying flow rate decreases over time at a rate proportional to the decreasing temperature of the heater plate.

[0143] In a configuration, the controller is configured to stop the drying mode if any one of the following occurs: (a) the drying mode has run for a predetermined duration; (b) the power supplied to heater wire(s) within a heatable breathing conduit follows a predefined power curve; and (c) a heating rate of the heater plate is greater than a threshold value. In a configuration, the controller is configured to monitor the power supplied to a heater wire(s) within a heatable breathing conduit and determine whether the power aligns with a predefined power curve as an indicator of whether the conduit contains moisture.

[0144] In a configuration, the controller is configured to receive or determine humidifier temperature data indicative or representative of a temperature of or relating to the humidifier, compare the humidifier temperature data to one or more safety thresholds when the apparatus is operated in the drying mode, and adjust the drying flow rate based on the comparison indicating that the temperature of or relating to the humidifier is less than one or more of the safety thresholds.

[0145] In a configuration, the controller is configured to adjust the drying flow rate based on the comparison indicating that the temperature of or relating to the humidifier is continuously less than one or more of the safety thresholds for a predetermined duration.

[0146] In a configuration, the apparatus includes one or more sensors configured to generate the humidifier temperature data or information for use in deducing the humidifier temperature data.

[0147] In a configuration, the temperature of the heater plate is measured as an indication of the temperature of the humidifier.

[0148] In a configuration, the controller is configured to carry out one or more moisture checks to detect the presence of moisture in a breathing conduit.

[0149] In a configuration, the or at least one moisture check is carried out during the drying mode.

[0150] In a configuration, the controller is configured to: a) retrieve at least one first signal associated with or indicative of a gases flow and / or pressure in the breathing conduit; b) determine a measure of at least one first parameter associated with gases flow perturbations and / or pressure perturbations for at least one portion of the retrieved at least one first signal; and c) determine the presence of liquid in the breathing conduit based at least in part on the measure(s) of the at least one first parameter meeting a first threshold.

[0151] In a configuration, the controller is configured to operate the drying mode until there is no, or low, moisture detected.

[0152] In a configuration, the perturbation signal is compared with a threshold to determine the presence of liquid.

[0153] In a configuration, the controller is configured to carry out a frequency analysis on the perturbations to detect the presence of liquid in the breathing conduit.

[0154] In a configuration, the or at least one moisture check comprises monitoring the temperature of the heater plate and the input power needed to maintain a set temperature of the heater plate, thereby determining whether the temperature of the heater plate aligns with a power curve.

[0155] In a configuration, the or at least one moisture check comprises monitoring the temperature of the heater plate while the heater plate provides a short heat pulse and / or monitoring the temperature of any heatable breathing conduit while heater wire(s) within the conduit provide a short heat pulse.

[0156] In a configuration, the controller is configured to receive or determine oxygen concentration data indicative or representative of a concentration of oxygen in the flow of gases, compare the oxygen concentration data to one or more safety thresholds when the apparatus is operated in or transitioning to the cooling mode or the drying mode, and switch operation of the apparatus from the cooling mode or the drying mode to a gas safety mode based on the comparison indicating that the concentration of oxygen in the flow of gases to the user exceeds one or more of the safety thresholds. In a configuration, the one or more safety thresholds comprise a pre-set value against which the oxygen concentration data is compared.

[0157] In a configuration, the one or more safety thresholds comprise a time-based threshold.

[0158] In a configuration, the comparison comprises assessing the oxygen concentration data against the one or more safety thresholds for a time-based threshold.

[0159] In a configuration, the controller is configured to switch operation of the apparatus from the gas safety mode back to the cooling mode.

[0160] In a configuration, the controller is configured to operate the apparatus in the following order: (a) therapy mode; (b) cooling mode; (c) gas safety mode; (d) cooling mode; and (e) drying mode.

[0161] In a configuration, the controller is configured to switch operation of the apparatus from the gas safety mode back to the drying mode.

[0162] In a configuration, the controller is configured to operate the apparatus in the following order: (a) therapy mode; (b) cooling mode; (c) drying mode; (d) gas safety mode; and (e) drying mode.

[0163] In a configuration, the plurality of non-therapy modes includes a standby mode.

[0164] In a configuration, the plurality of non-therapy modes includes a disinfection mode.

[0165] In a configuration, when the apparatus is operated in the disinfection mode, the controller is configured to operate the flow generator at a flushing flow rate to flush the gases flow path. In a configuration, the flushing flow rate is configured to flush any supplemental oxygen from the gases flow path of the apparatus.

[0166] In a configuration, the flushing flow rate is at least 10 L / min.

[0167] In a configuration, the flushing flow rate is at least 15 L / min.

[0168] In a configuration, the controller is configured to operate the flow generator at two or more flushing flow rates during the disinfection mode.

[0169] In a configuration, the controller is configured to operate the flow generator at the or each flushing flow rate automatically based on the comparison indicating that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds.

[0170] In a configuration, the controller is configured to operate the flow generator at the or each flushing flow rate based on user input relating to the manual initiation of a flushing flow.

[0171] In a configuration, the user input relating to the manual initiation of the flushing flow is received via a user interface.

[0172] In a configuration, the controller is configured to operate the flow generator at the or each flushing flow rate for a predetermined duration.

[0173] In a configuration, the controller is configured to operate the flow generator at the or each flushing flow rate until the concentration of oxygen in the flow of gases is less than or equal to one or more of the safety thresholds.

[0174] In a configuration, the heater plate is controlled to no power or low power when the flow generator is operated at the flushing flow rate. In a configuration, the or any heater wire(s) of the or any heatable breathing conduit are controlled to no power or low power when the flow generator is operated at the flushing flow rate.

[0175] In a configuration, the non-therapy modes comprise at least a cooling mode, a gas safety mode, and a drying mode; and the apparatus comprises a controller, wherein the controller is configured to: selectively either: operate the flow generator at a therapy flow rate and operate the heater plate at one or more therapy power levels to provide a humidified flow of gases along a gases flow path to the user for respiratory therapy, when the apparatus is operated in the therapy mode; operate the flow generator according to a cooling flow rate and / or the heater plate to a controlled power level to cool at least a portion of the gases flow path, when the apparatus is operated in the cooling mode; or operate the flow generator according to a drying flow rate and / or the heater plate at no power or to a controller power level to dry at least a portion of the gases flow path, when the apparatus is operated in the drying mode; detect the conclusion of the therapy mode and operate the apparatus in the cooling mode at the detected conclusion of the therapy mode to cool the heater plate and / or other components of the humidifier; switch operation of the apparatus to the drying mode; receive or determine oxygen concentration data indicative or representative of a concentration of oxygen in the flow of gases; compare the oxygen concentration data to one or more safety thresholds when the apparatus is operated in or transitioning to the drying mode; and switch operation of the apparatus to the gas safety mode or shut off an oxygen supply based on the comparison indicating that the concentration of oxygen in the flow of gases to the user exceeds one or more of the safety thresholds.

[0176] In a configuration, the non-therapy modes comprise at least a cooling mode, a gas safety mode, and a drying mode; and the apparatus comprises a controller, wherein the controller is configured to: operate a cooling mode, enter drying mode at the end of the cooling mode, and periodically during cooling mode or drying mode or during both modes detect the presence of oxygen or a patient, and activate a gas safety mode if oxygen is detected above a threshold or alarm or deactivate the apparatus or one or more components of the apparatus or one or more components connected to the apparatus if a patient is detected.

[0177] In a configuration, the therapy mode may be a high flow therapy mode or a pressure therapy mode, and the non-therapy modes may be one or more of a cooling mode, a drying mode, or a gas safety mode.

[0178] In a configuration, the respiratory apparatus may be part of a respiratory system, the respiratory system is configured to provide a flow of gases to a patient and provide respiratory therapy. The respiratory system may comprise a tube (i.e., a breathing tube) configured to carry gases from the respiratory apparatus to the patient.

[0179] In a configuration, the respiratory system may comprise a patient interface. The patient interface may be selected from an unsealed interface or a sealed interface, depending on the type of therapy mode. In a high flow therapy mode, a non-sealing interface is selected and in a pressure therapy mode a sealed interface is selected.

[0180] In a configuration, the pressure therapy mode may be bilevel pressure therapy mode (NIV mode) or a continuous positive airway pressure mode (CPAP mode). The breathing tube may comprise a heater wire that extends through the breathing tube and the heater wire may be controlled to heat gases within the tube.

[0181] In a configuration, the respiratory apparatus is configured to activate a cooling mode at the end of a therapy and then activate drying mode once cooling mode ends.

[0182] In one configuration in cooling mode, the apparatus (or controller of the apparatus) is configured to: activate the blower to a setpoint receive temperature signals of the heater plate, compare if the temperature is greater than a threshold, if yes the controller continues to control the blower at the setpoint, and if the temperature of the heater is below the threshold the controller is configured to switch off the blower.

[0183] In one configuration, the blower may be controlled to output a set flow rate or operated at a set motor speed. In one example, the set motor speed or set flow rate may be a maximum.

[0184] In one configuration, during cooling mode the heater plate and heater wire of the breathing tube may be switched off. Alternatively, the heater wire may be controlled to a temperature to reduce the formation of condensation e.g., 2 to 3 degrees above the temperature at the outlet of the humidification chamber. The apparatus may comprise a temperature sensor positioned at or adjacent the humidification chamber outlet.

[0185] In one configuration, the apparatus may be configured to operate in one of a multiple different type of drying modes. In one configuration, a user may select a specific type of drying mode via a user interface e.g., a screen. In one configuration a user may select a button or select a type of drying to initiate.

[0186] In one configuration, the drying mode may be as described in any one or more of the configurations above.

[0187] In one configuration, the selected drying mode may be one of a background drying mode, a maximum drying mode i.e., full power drying mode. In a further configuration, the selected drying mode may be one of a background drying mode, maximum drying mode or a smart drying mode.

[0188] In one configuration, the background drying mode or maximum drying mode may operate for a specific or set time threshold. In one example, in the background drying mode the controller is configured to operate the blower such that the noise from the blower is less than 30 dBA. In one configuration, in background drying mode the heater plate may be switched off and the blower and heater wire may be controlled to reduce power consumption as compared to the power draw in the maximum drying mode. For example, the blower may be controlled to less than 3000rpm or to produce a max flow of 15L / min, while the heater wire may be operate at 20% duty cycle or less.

[0189] In one example, in a maximum drying mode the blower may be controlled to the maximum allowable motor speed (e.g., up to 10k rpm), or to the maximum allowable flow rate (e.g., up to 80L / min) and the heater wire may be controlled to 100% duty cycle. The heater plate may be switched off or may be activated to provide a small power e.g., 5% duty cycle.

[0190] In one example, both the maximum drying mode and background drying mode, the drying mode may be operated for a predefined period of time.

[0191] In one configuration, the drying mode may be smart drying mode. In smart drying mode, the controller may be configured to determine a specific end condition or stop condition being reached. If a stop condition is reached the drying mode is ended.

[0192] Optionally, the drying mode may be initiated after a cooling mode is ended.

[0193] In one example, the smart drying mode may be as per one of the configurations described above.

[0194] In one example, the stop condition may be based on one of a time threshold being reached, determine if a tube is dry or substantially dry, a chamber is dry. Optionally, the drying mode may end if one or more of the stop conditions is achieved. Optionally, drying mode may stop or the apparatus may deactivate if two or more of the stop conditions are achieved. In a further option, the drying mode may deactivate if the chamber is determined as dry and the tube is determined as dry.

[0195] In one configuration the tube may be determined to be dry based on power curve. In one configuration the chamber may be determined as dry once the temperature of the heater plate drops below a temperature threshold or if the heating rate is below a threshold.

[0196] In one example, the stop conditions may be as per any one of the conditions described above.

[0197] Any one of the aspects of the present disclosure described in the paragraphs above may further have any one or more of the features described in respect of any one or more of the other aspects of the present disclosure described in the paragraphs above.

[0198] BRIEF DESCRIPTION OF THE DRAWINGS

[0199] These and other features, aspects, and advantages of the present disclosure are described with reference to the drawings of certain embodiments, which are intended to schematically illustrate certain embodiments and not to limit the disclosure.

[0200] Figure 1 shows schematically a respiratory therapy system configured to provide a respiratory therapy to a patient.

[0201] Figure 2 shows a block diagram of a control system interacting with and / or providing control and direction to components of a respiratory system.

[0202] Figure 3 shows a front-left perspective view of an example respiratory apparatus with a humidification chamber in position.

[0203] Figure 4 shows a left view corresponding to Figure 3.

[0204] Figure 5 shows a top view corresponding to Figure 3.

[0205] Figure 6 shows a bottom view corresponding to Figure 3.

[0206] Figure 7 shows a rear-right-bottom perspective view corresponding to Figure 3. Figure 8 shows a flow chart that illustrates a maximum drying mode process followed by a controller in a drying mode.

[0207] Figure 9 shows a flow chart that illustrates a background drying mode process followed by a controller in a drying mode.

[0208] Figure 10 shows a flow chart that illustrates a smart drying mode process followed by a controller in a drying mode.

[0209] Figure 11 shows a flow chart that illustrates a moisture detection process followed by a controller in a drying mode.

[0210] Figure 12 shows a flow chart that illustrates a patient detection process followed by a controller in a drying mode.

[0211] Figure 13 shows a flow chart that illustrates an oxygen safety check process followed by a controller at the completion of a therapy mode.

[0212] Figure 14 shows a flow chart that illustrates an oxygen safety check process followed by a controller operating in a drying mode, including the process following a switch to a gas safety mode.

[0213] Figure 15 shows a flow chart that illustrates a non-therapy mode selection process followed by a controller after operating in a therapy mode.

[0214] Figure 16 shows a flow chart that illustrates a fast-cooling mode process followed by a controller in a cooling mode.

[0215] Figure 17 shows a flow chart that illustrates an example implementation followed by a controller operating in a cooling mode, including the processes following a switch to a gas safety mode or a drying mode.

[0216] Figure 18 shows a flow chart that illustrates a further example implementation followed by a controller progressing from cooling mode to drying mode.

[0217] DETAILED DESCRIPTION

[0218] Although certain examples are described below, those of skill in the art will appreciate that the disclosure extends beyond the specifically disclosed examples and / or uses and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the disclosure herein disclosed should not be limited by any particular examples described below.

[0219] 1. Overview of Example Respiratory Apparatus

[0220] Examples of the respiratory apparatuses will be described in the context of an example respiratory apparatus 10 that is configured or operable to provide nasal high flow therapy via an unsealed patient interface 30, e.g., a nasal cannula or an unsealed tracheal interface. This is intended as a non-limiting example. It will be appreciated that the safety improvements may be applied to other respiratory apparatus or systems and / or to other modes of operation and / or modes of therapy delivered by such apparatus.

[0221] A schematic representation of an example respiratory therapy system 1 containing a respiratory apparatus 10 is provided by Figure 1. The respiratory therapy system 1 may comprise at least a respiratory apparatus 10, a breathing conduit 20, and an unsealed patient interface 30. Other modules or elements may be present in the system. Hereinafter, the apparatus comprising a flow generator 11 and a humidifier 12 will be referred to as a ‘respiratory apparatus’, whereas the system comprising the flow generator 11, humidifier 12, breathing conduit 20 in fluid communication with the humidifier, and unsealed patient interface 30 will be referred to as a ‘respiratory therapy system’, but these terms should not be considered limiting. In some circumstances, the respiratory therapy system 1 may omit the patient interface 30.

[0222] An exemplary respiratory apparatus will now be described, with reference to Figures 1 to 7. This is intended as a non-limiting example of a respiratory apparatus that can be supported on a support stand in accordance with this disclosure. Respiratory apparatus 10 is configured or operable to provide respiratory therapy via the breathing conduit 20 and the unsealed patient interface 30. The patient interface 30 is coupled to the breathing conduit 20 and supplies humidified gases to the user. It will be appreciated that the components, methods and processes described herein may be applied to other respiratory apparatus and / or other modes of operation and / or modes of therapy delivered by such apparatus. For example, the respiratory apparatus 10 may additionally or alternatively be configured or operable to provide pressure-based therapies such as continuous positive airway pressure (CPAP) therapy and / or bi-level positive airway pressure (bi-level) therapy. When providing such therapies, the patient interface 30 may be a sealed interface, such as nasal pillows, a nasal mask, an under-nose mask, or a full-face mask. The respiratory apparatus 10 may be configured or operable to provide two or more therapy modes. In one embodiment, the controller 14 is configured to provide a first therapy mode comprising high flow therapy and a second therapy mode comprising a pressure-based therapy, such as bi-level therapy or CPAP therapy.

[0223] 1.1 Flow Path

[0224] The respiratory apparatus 10 may be an integrated apparatus comprising a plurality of key components in a single housing or a discrete component-based arrangement where the key components are separate but connected together.

[0225] With reference to Figure 1, the respiratory apparatus 10 comprises at least a flow generator 11 and a humidifier 12. With reference to Figures 3 to 7, in some configurations, the flow generator 11 and humidifier 12 are part of an integrated respiratory apparatus 10, sharing a common housing 16. In other configurations, the respiratory apparatus 10 could be a modular arrangement of discrete components, with the flow generator 11 and humidifier 12 being separate modules that can be connected together.

[0226] The respiratory apparatus 10 comprises an inlet module 110 for providing a gas or gases such as air, oxygen (O2), air blended with oxygen, or a mix of air and / or oxygen and one or more other supplemental gases to the flow generator 11. The inlet module 110 may comprise one or more inlets for receiving flows of (or drawing in) ambient and / or pressurised air, oxygen, and / or other gases. For example, with reference to Figure 1, in some embodiments, the inlet module 110 may comprise an ambient air inlet 1101, low- pressure gas inlet 1102, and / or high-pressure gas inlet 1103. A greater or lesser number of inlets may be provided in other embodiments. Some or all of the inlets may comprise connectors (such as ports, terminals, couplers, and the like) for establishing fluid or pneumatic connections to the sources of said gases. The inlet module 110 may be considered to form part of the flow generator 11, the respiratory apparatus 10, or it may be a separate, modular component, depending on the context.

[0227] With reference to Figure 1, a filter or multiple filters may be provided as part of the inlet module 110, at or immediately downstream of the ambient air intake 1101, the low- pressure gas inlet 1102, and / or the high-pressure gas inlet 1103. A single filter 1106 may be positioned at the inlet or inlets to blower 1111 to filter particulates and pathogens carried with the incoming gases before they reach the blower 1111. Additionally, or alternatively, there may be individual filters positioned at each of the inlets or intakes 1101, 1102, 1103. In an exemplary embodiment, a filter 1104 is provided between the high-pressure gas inlet 1103, at or upstream of the optional proportional valve 1105, where present, in addition to a filter 1106 positioned at the inlet or inlets to the blower 1111, downstream of the proportional valve 1105 and the intake 1101 and inlet 1102.

[0228] According to the above and depending on the configuration (some components may be optional), the respiratory therapy system 1 can include a combination of components or modules selected from the following:

[0229] • a flow generator 11, comprising an inlet module 110, comprising one or more gas source inlets and their respective connectors (if applicable), a filter or filter module 1106, and a blower / sensor module 111,

[0230] • an optional non-retum valve (NRV) 112,

[0231] • a humidifier 12 for humidifying the gases flow,

[0232] • a breathing conduit 20, and / or

[0233] • a patient interface 30. The respiratory therapy system 1 and respiratory apparatus 10 will now be described in more detail.

[0234] The gas sources connected to the inlet module 110 or inlets of the inlet module may comprise a tank of supplementary gases (e.g., oxygen) and / or an oxygen concentrator. The gas sources may provide the respective gas or gases at low or high pressures and / or low or high flow rates. For example, in an embodiment with the proportional valve 1105, high-pressure gases inlet 1103 could be connected to a pressurised gas cylinder, e.g., an oxygen tank, via a pressure control means such as a regulator and / or shut-off valve. The pressure control means may be manually adjustable by a user. Alternatively, in an embodiment without the proportional valve 1105, inlet 1103 could be connected to an oxygen concentrator.

[0235] The flow generator 11 comprises a blower / sensor module 111 that at least comprises a blower 1111 that controls flows delivered to a patient via the breathing conduit 20 and patient interface 30. The blower 1111 may be a centrifugal blower, comprising at least a motor and impeller or fan that is driver by the motor. Other types of blowers may be employed, such as axial blowers. The flow rate and / or pressure of flows of gases being output by the flow generator 11 can be controlled by varying the output of the blower 1111, for example, by varying the rotational speed of the motor driving the impeller or fan. The flow generator may be configured to provide flows of gases at high flow rates. Examples of high flow rates are provided later.

[0236] The blower / sensor module 111 may further comprise a sensor module 1112. With reference to Figure 1, in some embodiments, the sensor module 1112 may be positioned ‘after’ or downstream of the blower 1111 (i.e., an inlet of the sensor module 1112 may be fluidically / pneumatically connected to the outlet of the blower 1111) but may instead be positioned upstream of the blower in other embodiments. The sensor module 1112 may be located prior to humidifier 12. One or more sensors (for example, Hall Effect sensors) may be used to measure a motor speed of the blower motor.

[0237] Positioning sensors (e.g., flow rate, pressure, oxygen fraction, and / or other types of sensors in the sensor module 1112) downstream of the blower 1111 can increase the accuracy of measurements, such as the measurement of fractional gas concentrations, including oxygen fraction, over systems that position the sensors upstream of the blower and / or a mixer. Positioning these sensors at a location further along the flow pathway, after the flow of gases has been more mixed (and may therefore be more homogeneous), may yield more consistent and / or repeatable measurements.

[0238] In some embodiments of the respiratory apparatus 10, an optional non-retum valve (NRV) 112 may be located between the flow generator outlet 113 and the humidification chamber 120. In other embodiments, the optional NRV 112 may be located downstream of the blower 1111 or blower / sensor module 111 but prior to the flow generator outlet 113 and / or the inlet to humidification chamber 120. In further disclosure, the optional NRV 112 may be positioned within the flow generator outlet 113. The non-retum valve 112 may serve to prevent any backflow of gases, aerosols, and / or liquids into the flow generator 11 via the humidifier 12. During the provision of respiratory therapy, some flows of gases expired by patients may travel down the breathing conduit 20, back into the humidifier 12 and potentially reach the flow generator or displace other gases that then travel into the humidifier and / or flow generator; these flows of gases may carry pathogens which could contaminate the flow generator. In addition, the flows of gases may transport significant quantities of water vapour (especially if returning via the humidifier 12) which, overtime, may damage the internal hardware of the flow generator if backflow is allowed to occur. Hence, a non-return valve 112 may optionally be included in the respiratory apparatus 10. 1.2 Patient Interface

[0239] The patient interface 30 may be an unsealed or non-sealed interface such as a nasal cannula. The term ‘non-sealing’, as used when referring to patient respiratory interfaces, may be defined as a patient interface having elements that do not completely seal a respiratory passage of the user from the outside environment.

[0240] The patient respiratory interface 30 may instead be a tracheostomy interface or any other suitable type of patient interface, depending on the type of therapy being provided and / or the patient’s needs.

[0241] A humidifier 12 is provided between the flow generator 11 and the apparatus outlet 13 and / or breathing conduit 20 to humidify the flow of gases being output by the flow generator 11. Humidification is particularly useful when providing high flow therapy (where high flow rates of otherwise dry gases are delivered to the patient’s airways) as it improves the tolerability and comfort of the therapy. Increasing the humidity of the gases to or closer to the natural levels in a healthy patient’s airways (e.g., 37°C dew point) may help to maintain the condition of the airways, reducing or preventing drying-out or other effects that may cause discomfort and adverse health outcomes. In some configurations, the humidifier 12 may be optional, in which case the respiratory apparatus 10 may provide non-humidified gases from the flow generator 11 to the patient.

[0242] The humidifier 12 may be an active humidifier, wherein the humidifier comprises at least one heating element. The humidifier 12 may be an active pass-over humidifier. An active pass-over humidifier typically comprises at least a heater plate 121, a heating element 122 arranged and configured to heat the heater plate 121, and a humidification chamber 120 comprising a heat-conductive base that is in close contact with the heater plate 121 when in use. The humidification chamber 120 will be at least partially filled with water when in use; the heat-conductive base will transfer heat from the heater plate to the water, thereby causing controlled evaporation of the water to increase the humidity of a gases flow travelling through the chamber.

[0243] 1.3 Sensors

[0244] Various sensors configured to detect or measure properties or parameters of the respiratory therapy system 1 and / or the flow of gases may be disposed at one or more locations throughout the system.

[0245] In an exemplary embodiment of the respiratory therapy system 1, at least the following sensors may be provided:

[0246] • Sensor 1107 at the ambient air inlet 1101 (e.g., a pressure, flow, temperature, and / or humidity (relative and / or absolute) sensor);

[0247] • Sensor 1108 at or optionally downstream of the high-pressure gas inlet 1103 (e.g., a pressure and / or a flow sensor);

[0248] • Sensor 1109 downstream of the optional proportional valve 1105 (e.g., a pressure and / or a flow sensor);

[0249] • Sensor 1113 at the blower 1111, optionally proximal to the stator windings of the motor driving the blower (e.g., a temperature and / or a motor speed sensor);

[0250] • Sensor 123 at the heating element 122, or proximal to the heater plate 121 (e.g., a temperature sensor);

[0251] • Sensor 130 downstream of the apparatus outlet 13 (e.g., a temperature sensor); and

[0252] • Sensor 21 at a patient end of the breathing conduit 20 (e.g., a temperature sensor).

[0253] Sensors 1107, 1108, 1109, 1113, 123, 130, and / or 21 may comprise multiple sensors. The multiple sensors may be part of a single package or separate, discrete sensors, or a combination of integrated sensor modules and discrete components. Additional sensors may be provided as part of or within the sensor module 1112. The sensor module 1112 may be configured and arranged to measure properties of the gases flow travelling from the blower 1111 through to flow generator outlet 113 and beyond. For example, the sensor module may comprise a sensor or sensors to detect the flow rate, oxygen concentration fraction (FdCh), pressure, temperature, and / or humidity of the flow of gases. The sensor module may also comprise a microphone sensor to detect and measure ambient noise levels (e.g., noise from the flow generator 11) and carry out speaker testing.

[0254] In addition to the sensors described above, various other sensors may be provided in and throughout the respiratory therapy system 1. The sensors may be configured to detect, measure, and / or determine flow rate, pressure, temperature, humidity (e.g., relative and / or absolute humidity), oxygen concentration / fraction, motor speed, and / or noise. Other sensors can be placed throughout the system and / or at, on or near the patient — for example, a pulse oximetry sensor may be attached to the patient and coupled to the controller 14 via a pulse oximeter. The patient interface 30 may contain one or more patient detection sensors configured to monitor the user's connection status to the patient interface, such as one or more pressure sensors embedded into the patient interface. Alternatively, or additionally, sensors from which the above parameters can be derived could be used.

[0255] 1.4 Controller

[0256] Some or all of the sensors listed above may be electrically and / or communicatively connected to a controller 14, as mentioned above. The connection may be direct or indirect — e.g., via signal conditioning circuits, driver circuits, another controller, and / or other types of circuits. The connection(s) may be wired or wireless.

[0257] The controller 14 may be a microprocessor, a microcontroller, a programmable logic device (such as a CPLD or FPGA), a digital signal processor (DSP), an application- specific integrated circuit (ASIC), or other suitable form of device, and may not necessarily be implemented in a single monolithic integrated circuit (IC) but may include additional discrete electrical and / or electronic components. The controller 14 may comprise a single device or multiple devices and components. For example, the controller 14 may comprise multiple microprocessors or microcontrollers. Overall, it will be appreciated by persons of skill in the art that various types of devices and components may be employed as or in controllers such as controller 14.

[0258] In some configurations, the outputs from at least some or all of the sensors described above are sent to the controller 14 to assist the control of the respiratory system 1 and its constituent components or modules (e.g., the blower 1111, heating element 122, breathing conduit 20, display and input / output (I / O) 142, and other modules). The controller 14 may be coupled to at least one or more of the optional proportional valve 1105, blower 1111, humidifier heating element 122, and / or the heated breathing tube of breathing conduit 20. In some configurations, the controller 14 controls at least these and other parts of the respiratory system 1 as described herein. ‘Control’ as referred to herein may involve direct control of components (i.e., by signals output from the controller 14) or control via signal conditioning circuits, drivers / driving circuits (such as MOSFET gate drivers or motor drivers, for example).

[0259] In some examples, the controller 14 can operate the blower 1111 to provide a flow of gas at a desired flow rate. Additionally or alternatively, the controller 14 can operate the optional proportional valve 1105 to provide the flow of gas at the desired flow rate. The controller 14 may also receive user input from a user interface aspect of the display and VO 142. The user input may include a target flow rate, pressure, oxygen fraction (i.e., FdO2 (fraction of delivered oxygen) or FiO2 (fraction of inspired oxygen)), therapy mode (high flow therapy, CPAP, etc.), alarm thresholds, and / or other parameters. The user can be a patient, healthcare professional, or others. The controller 14 may output information to a display and I / O peripheral 142. The display and I / O peripheral 142 can display warnings and / or other alerts. The display and I / O peripheral 142 can be configured to display characteristics of sensed gases in real time or otherwise. The controller 14 can also receive user inputs via a user interface aspect of the display and I / O peripheral 142. The user interface can include virtual and / or physical button(s) and / or dial(s). The user interface can comprise a touch-sensitive screen.

[0260] 1.5 Wireless Communications

[0261] The respiratory apparatus 10 may include one or more communications modules 141 which can enable data communications with one or more external devices or servers over a data or communication link or data network, whether wired, wireless or a combination thereof. In one configuration, for example, the respiratory apparatus 10 can include a wireless data transmitter, receiver, and / or transceiver to enable the controller 14 to send and receive data signals in a wireless manner to / from external devices, including sensors, patient monitoring systems, mobile phones or other devices, and / or remote servers. In one example, the one or more communications modules 141 may comprise cellular (e.g., 3G, 4G, and / or 5G), Bluetooth, and / or Wi-Fi modules. The one or more communications modules 141 may comprise a singular module configured to perform communication using cellular, Bluetooth, and Wi-Fi technologies and protocols.

[0262] The one or more communications modules 141 can deliver data to a remote patient management system 144 (for example, implemented or located on a remote server) and / or enable remote control of the respiratory apparatus 10 or respiratory system 1. The remote patient management system 144 may comprise a single server, multiple servers, or multiple computing devices implemented in a cloud computing network. The communication may be two-way (bidirectional) communication between the respiratory apparatus 10 and the remote patient management system 144, and / or another remote system. The one or more communications modules may allow the controller 14 to wirelessly send information to another local device such as, for example, a user or patient’s mobile phone, tablet, smartwatch, etc. The respiratory apparatus 10 may additionally, or alternatively, comprise a Near Field Communication (NFC) module to allow for local data transfer and / or data communication. In some examples, the respiratory apparatus 10 may transmit data over a wired or wireless connection to the local user or patient device, for example, via USB, Wi-Fi, Bluetooth, or NFC, and the user or patient device may then wirelessly transmit data to a remote server, such as the remote patient management system 144 (for example, via the Internet).

[0263] As mentioned above, estimated, measured, or determined respiratory parameters that are generated or received by the respiratory apparatus 10 may be transmitted via the one or more communications modules 141 to a remote server. In addition, usage information and selected therapy parameters may also be transmitted. Therapy parameters — e.g., flow rate, humidity level and other respiratory parameters such as respiratory rate, occurrences of apnoeas, pulse oximetry data (e.g., SpCh) — may be transmitted together. In some examples, the respiratory apparatus 10 or the user or patient device may generate an index (for example, a respiratory oxygenation (ROX) index) that contains, comprises, or is based on therapy parameters — e.g., patient SpCh, device FdCh or FiCh, flow rate, humidity level, and other determined or estimated respiratory parameters — and is transmitted by the respiratory apparatus 10 or the user or patient device to a remote server.

[0264] The remote patient management system 144 may be implemented on a single server or a network of servers or a cloud computing system or other suitable architecture for operating a remote patient management system. The remote patient management system 144 may further include memory for storing received data and various software applications or services that can be executed to perform multiple functions. Then, for example, the remote patient management system 144 may communicate information or instructions to the respiratory apparatus 10, at least in part, dependent on the data received. For example, the nature of the data received may trigger the remote server (or a software application running on the remote server) to communicate an alert, alarm, or notification to the respiratory apparatus 10. The remote patient management system 144 may further store the received data for access by an authorised party such as a clinician, the patient, or another authorised party. The remote patient management system 144 may further be configured to generate reports in response to a request from an authorised party, and respiratory or selected therapy parameters may be included in the generated reports. The reports may comprise other data or patient breathing or respiratory parameters, e.g., respiratory rate, SpCh, and / or device parameters such as flow rate(s), pressure(s), temperature(s), and / or humidity level(s).

[0265] 1.6 Control System

[0266] Figure 2 illustrates a block diagram of an example control system 310, which can be implemented on, by, or at least partially on or by the controller 14 (and any other controllers or circuits described herein) that can detect patient and / or system conditions and control operation of the respiratory therapy system 1, including any gases source(s). The control system 310 can determine and generate the output control signals 322-326 based on one or more received inputs 311-321. The inputs 311-321 can correspond to sensor measurements received automatically by the controller 14 and / or user inputs. The control system 310 can receive, including but not limited to, pressure sensor(s) input(s) 311, temperature sensor(s) input(s) 312, flow rate sensor(s) input(s) 313, motor speed sensor(s) input(s) 31, gas fraction / concentration sensor(s) input(s) 315, humidity sensor(s) input(s) 316, pulse oximetry sensor(s) input(s) 317 (for example, SpCh and / or heart rate), stored or user parameter(s) input(s) 318, duty cycle or pulse width modulation (PWM) input(s) 319, voltage(s) input(s) 320, current(s) input(s) 3211.

[0267] 1.7 Respiratory Apparatus Housing

[0268] With reference to Figures 3 to 7, the respiratory apparatus 10 can include a main housing 16. The housing 16 may house the inlet module 110, blower / sensor module 111, and the heater plate 121 and heating element 122 of the humidifier 12. The controller 14, communications modules 141, display and I / O 142, and peripheral ports 143 may also be positioned within or on the main housing 16. As mentioned above, the humidifier 12 may, in some embodiments, be a separate module with its own housing and, therefore, not enclosed by the main housing 16 of the respiratory apparatus 10.

[0269] The main housing 16 has a main housing upper chassis 161 and a main housing lower chassis 162. The main housing upper chassis 161 has a peripheral side wall 1611. The peripheral wall defines a humidifier or humidification chamber bay dock, compartment, or bay 1612 for receipt of the removable humidification chamber 120. The removable humidification chamber 120 contains a suitable liquid for humidifying gases that can be delivered to a patient, such as water. A floor portion of the humidification chamber dock 1613 (not shown) can have a recess to receive a heater arrangement such as a heater plate 121 or other suitable heating arrangements(s) for heating liquid in the humidification chamber 120 during a humidification process.

[0270] The respiratory apparatus 10 comprises an arrangement to enable the blower to deliver air, oxygen (or alternative auxiliary gases), or a suitable mixture thereof to the humidification chamber 120 and thereby to the patient. This arrangement can include an air inlet 1101 in the peripheral side wall 1611 of the lower chassis 162 of the housing 16. Additionally, or alternatively, the air inlet 1101 may be positioned in an underside wall 1615 of the housing 16.

[0271] A filter cartridge can be positioned adjacent the air inlet 1101 internally in the main housing and in communication with the blower 1111 to deliver filtered air and / or oxygen to the blower 1111 via an inlet port in the motor / sensor module 111. The filter cartridge can include a filter 1106 configured to remove particulates (e.g., dust) and / or pathogens (e.g., viruses or bacteria) from the gases flow. The apparatus 10 can include a separate oxygen inlet port 1103 positioned adjacent one side of the housing 16 or at a rear end thereof, the oxygen port 1103 being for receipt of oxygen from an oxygen source such as a tank or source of piped oxygen. The oxygen inlet port 1103 may be in fluid communication with an optional proportional valve 1105. The proportional valve 1105 can suitably be a solenoid valve that enables electronic control of the amount of oxygen that is added to the gases flow that is delivered to the humidification chamber 120.

[0272] With reference to Figures 3 to 5, an apparatus outlet port 13 can include a removably- connected (removable) L-shaped elbow 131. The removable elbow 131 can include a gases outlet port 1311 for coupling to the breathing conduit 20 to deliver a flow of gases to a patient interface. The inlet to the removable elbow 131 may extend at least substantially along the longitudinal axis 60 while the outlet of the removable elbow 131 (i.e., the gases outlet port 1311) may extend at least substantially along a vertical axis 62. In other words, the gases outlet port 1311 may extend upwardly from the main housing upper chassis 161 of the respiratory apparatus 10 main housing 16. The removable elbow 131 may be washable for disinfection, for example, in a homecare environment.

[0273] The flow generator outlet port 113, gases inlet and gases outlet ports 124, 125 of the humidifier 12 (or the inlet and outlet ports of the manifold 126), apparatus outlet port 13, and gases outlet port 1311 each or all can have soft seals such as O-ring seals or T-seals to provide a sealed gases passageway between the flow generator 11, the humidification chamber 120, and the breathing conduit 20.

[0274] The main housing upper chassis 161 can comprise a shroud portion 1614 (hereinafter ‘shroud’). With reference to Figures 3 and 4, the shroud 1614 can protrude outwardly from the main upper housing chassis 161, such that it may extend at least partially over the flow generator outlet 113 and the inlet to the elbow 131.

[0275] The main housing upper chassis 161 may further comprise the display and VO 142 mentioned previously. The display and I / O 142 can include a user interface that may comprise a display screen and input devices such as mechanical buttons or dials, a touch screen (e.g., a touch-sensitive LCD or LED screen), a combination of a touch screen and mechanical buttons or dials, or the like. In one configuration, the user interface of the display and I / O 142 may comprise a separate display and / or touch screen that is not permanently integrated with the respiratory apparatus housing 16 but may be communicatively connected to the apparatus in a wired or wireless fashion. The respiratory apparatus 10 may comprise a docking element for securing the separate display screen to the housing 16.

[0276] With reference to Figures 3 to 5, the respiratory apparatus 10 may at least comprise a display screen 1420 that may be part of the display and I / O 142 (i.e., it may be the aforementioned display screen or touch-sensitive screen). With reference to Figures 3 to 5, the display screen 1420 can protrude from the housing 16, for example, in an angled fashion. The angle of the display screen relative to a plane defined by the surface of the main housing upper chassis 161 may help to improve visibility and / or usability of the screen for users. For example, an angled display screen may be more easily viewed from a distance than a completely flat screen provided in the main housing upper chassis 161.

[0277] 1.8 Humidification

[0278] With continued reference to Figure 1, a breathing conduit 20 can be coupled to an apparatus outlet 13 formed in or as part of the housing 16 of the respiratory apparatus 10 at one end, and to a patient interface 30, such as a non-sealing interface (for example, a non-sealing nasal cannula) at another end.

[0279] The gases flow generated by the flow generator 11 may be humidified before being delivered to the patient via the breathing conduit 20 and the patient respiratory interface 30, as explained previously. The controller 14 can control the flow generator 11 to generate a gases flow of a desired flow rate, and / or one or more valves (such as the optional proportional valve 1105) to control the mixing of air and oxygen and / or other supplemental gases by the blower 1111. The controller 14 can control a heating element 122 in or associated with the humidifier 12, if present, to heat the gases flow to a desired temperature that achieves a desired level of temperature and / or humidity for delivery to the patient. The breathing conduit 20 may be a heated conduit, comprising one or more heater elements (e.g., heater wires) embedded within the walls of the breathing conduit, which may be supplied with electrical current to heat the internal passageway(s) of the conduit. Alternatively, the heating element(s) may be attached to the interior surface of the breathing conduit 20, or even float within the interior of the conduit. The power supplied to the heating elements can be controlled by the controller 14.

[0280] The humidifier 12 of the apparatus is configured to increase the humidity of the gases flow by introducing water vapour to gases passing through the humidification chamber 120. Various humidifier configurations may be employed. In one configuration, the humidifier 12 can comprise a removable humidification chamber 120 configured to contain one or more liquids. For example, the humidifier 12 may be configured to allow the humidification chamber 120 to be partially or entirely removed or disconnected from the flow path and / or respiratory apparatus 10. The humidification chamber may be removed for refilling, cleaning, replacement and / or repair. With reference to at least Figures 3 to 5, in one configuration, the humidification chamber may be received and retained by or within a dock, compartment, or bay 1612 of the respiratory apparatus 10 or may otherwise couple onto or within the housing 16 of the respiratory apparatus 10.

[0281] With continued reference to at least Figures 3 to 5, the humidification chamber 120 of the humidifier 12 comprises at least a gases inlet 124 and a gases outlet 125 to enable connection to the gases flow path of the respiratory apparatus 10, optionally via a gases manifold 126 that connects between the flow generator outlet 113 and humidifier gases inlet 121, and the humidifier gases outlet 124 and apparatus outlet 13. For example, the flow of gases from the outlet 113 of the flow generator 11 is received into the humidification chamber via its gases inlet and exits the chamber via its gases outlet, after being heated and / or humidified. The humidification chamber 120 may be configured to contain a volume of liquid, typically water. In operation, the liquid in the humidification chamber is controllably heated by one or more heaters (e.g., heater plate 121) or heating elements (e.g., heating element 122 of the heater plate 121) associated with the humidifier 12 to generate water vapour and thereby increase the humidity of the gases flowing through the chamber 120.

[0282] In one embodiment, the respiratory apparatus 10 comprises a housing 16 with a compartment to receive the humidification chamber 120. The compartment may include a heater plate 121 at the base. The humidification chamber 120 may be inserted into the compartment for use and retained in the compartment such that the conductive base of the chamber contacts the heater plate 121 and heats the contents of the chamber to create water vapour to humidify gases passing through the chamber. The compartment may be enclosed by a lid. Optionally, the humidification chamber 120 may also include a hinged lid that can open and close. The lid of the humidification chamber 120 may be opened to allow the chamber to be filled with water.

[0283] 1.9 High Flow Therapy

[0284] The respiratory apparatus 10 may be a high flow therapy apparatus. High flow therapy, as discussed herein, is intended to be given its typical ordinary meaning, as understood by a person of skill in the art, which generally refers to a respiratory system delivering a targeted flow of humidified respiratory gases via an intentionally unsealed or non-sealing patient interface with flow rates generally intended to meet or exceed the inspiratory demand of a user. High flow therapy is typically provided at desired flow rates high enough to meet or exceed a patient’s inspiratory demand. The flow rate provided is ideally sufficient, such that, ambient gases are not entrained as the patient inspires. Typical patient interfaces used for high flow therapy include, but are not limited to, a non-sealing nasal cannula or a tracheal patient interface. Typical flow rates for adults often range from, but are not limited to, about fifteen litres per minute to about sixty litres per minute or greater. Typical flow rates for paediatric users (such as neonates, infants and children) often range from, but are not limited to, about one litre per minute per kilogram of user weight to about three litres per minute per kilogram of user weight or greater.

[0285] High flow therapy can also optionally involve the delivery of gas mixture compositions, including supplemental oxygen and / or administration of therapeutic medicaments.

[0286] High flow therapy is often referred to as nasal high flow (NHF), humidified high flow nasal cannula (HHFNC), high flow nasal oxygen (HFNO), high flow therapy (HFT), or tracheal high flow (THF), among other common names. For example, in some configurations, for an adult patient ‘high flow therapy’ may refer to the delivery of gases to a patient at a flow rate of greater than or equal to about 10 litres per minute (10 LPM), such as between about 10 LPM and about 100 LPM, or between about 15 LPM and about 95 LPM, or between about 20 LPM and about 90 LPM, or between about 25 LPM and about 85 LPM, or between about 30 LPM and about 80 LPM, or between about 35 LPM and about 75 LPM, or between about 40 LPM and about 70 LPM, or between about 45 LPM and about 65 LPM, or between about 50 LPM and about 60 LPM.

[0287] In some configurations, for a neonatal, infant, or child patient ‘high flow therapy’ may refer to the delivery of gases to a patient at a flow rate of greater than 1 LPM, such as between about 1 LPM and about 25 LPM, or between about 2 LPM and about 25 LPM, or between about 2 LPM and about 5 LPM, or between about 5 LPM and about 25 LPM, or between about 5 LPM and about 10 LPM, or between about 10 LPM and about 25 LPM, or between about 10 LPM and about 20 LPM, or between about 10 LPM and 15 LPM, or between about 20 LPM and 25 LPM. A high flow therapy apparatus with an adult patient, a neonatal, infant, or child patient, may deliver gases to the patient at a flow rate of between about 1 LPM and about 100 LPM, or at a flow rate in any of the subranges outlined above.

[0288] High flow therapy can be effective in meeting or exceeding the patient's inspiratory demand, increasing oxygenation of the patient and / or reducing their work of breathing. Additionally, high flow therapy may generate a flushing effect in the nasopharynx such that the anatomical dead space of the upper airways is flushed by the high incoming gases flow. The flushing effect can create a reservoir of fresh gas available of each and every breath, while minimising the re-breathing of carbon dioxide, nitrogen, etc. High flow therapy can also increase the expiratory time of the patient due to pressure provided during expiration. This, in turn, reduces the respiratory rate of the patient.

[0289] 1.10 Ultrasonic Sensing System Details

[0290] Ultrasonic sensors can be used to determine the oxygen concentration in the flow of gases by measuring the change in the speed of sound. In one ultrasonic sensing (including ultrasonic transmitters and / or receivers) topology, a driver causes a first sensor, such as an ultrasonic transducer, to produce an ultrasonic pulse in a first direction. A second sensor, such as a second ultrasonic transducer, receives this pulse and provides a measurement of the time of flight of the pulse between the first and second ultrasonic transducers. Using this time-of-flight measurement, the speed of sound of the gases flow between the ultrasonic transducers can be calculated by a processor or controller of the respiratory system. The second sensor can transmit and the first sensor can receive a pulse in a second direction opposite the first direction to provide a second measurement of the time of flight, allowing the concentration of oxygen in the gases flow, to be determined. In another acoustic sensing topology, acoustic pulses transmitted by an acoustic transmitter, such as an ultrasonic transducer, can be received by acoustic receivers, such as microphones.

[0291] In one example configuration, an oxygen sensor or sensors, or sensor assembly, may be located in the main device housing 16 before or after the humidifier 12. For example, the oxygen sensor may be arranged or configured in the main device housing 16 to sense the oxygen concentration of the gases in the flow path at a location between the flow generator 11 and humidifier 12, or a location in the flow path after the humidifier. In another example configuration, an oxygen sensor or sensors, or sensor assembly, may be located in or along the breathing conduit 20 and / or patient interface 30. In this configuration, the sensor or sensor assembly is configured to sense or measure the oxygen concentration of the gases flow in the flow path comprising or formed by the breathing conduit 20 and / or patient interface 30, i.e., the flow path that follows the apparatus outlet 13. In another example configuration, the apparatus may comprise any combination of the mentioned one or more oxygen sensor or sensor assembly configurations or locations. For example, the apparatus may comprise any combination of one or more oxygen sensors or sensor assemblies in any one or more locations along the gases flow path, whether in the main device housing, breathing conduit 20, and / or patient interface 30.

[0292] 2. Example Operational Modes of Respiratory Apparatuses

[0293] Example operational modes for respiratory apparatuses will be described in the context of the example respiratory apparatus 10 described above, which is configured to provide a flow of gases to a user for respiratory therapy.

[0294] 2.1 Therapy Mode

[0295] The respiratory apparatus 10 may be operable in one of a plurality of therapy modes, which may also be referred to as therapy types, options, selections, configurations, therapies, or similar. The therapy mode the respiratory apparatus 10 operates in may be determined by user selection. Each therapy mode may correspond to specific operational parameters of the respiratory apparatus 10 and may correspond to specific operational functions. The respiratory apparatus 10 may be broadly able to operate in a high flow therapy mode, which may set a flow rate as a target parameter for the gases flow delivered to the patient, and it may broadly be able to operate in a pressure therapy mode, which may set a pressure as a target parameter for the gases flow delivered to the patient.

[0296] The respiratory apparatus 10 can have a user interface of the display and VO 142 through which the user may determine the therapy mode and may control the initiation and termination of the therapy mode. Optionally, the user interface may be operable to adjust respiratory therapy settings.

[0297] The respiratory apparatus 10 may be configured to deliver nasal high flow (NHF) therapy as the high flow therapy, and one or both of Bi-level Positive Airway Pressure (Bi-level) therapy or Continuous Positive Airway Pressure (CPAP) therapy as the pressure therapy. The possible therapy modes are described in more detail below.

[0298] When the respiratory apparatus 10 is operated in a therapy mode, for example, providing high flow therapy or pressure therapy, the controller 14 operates the flow generator 11 at an appropriate therapy flow rate and / or an appropriate pressure for the therapy. For example, during high flow therapy, the flow generator 11 is operated to provide the user with a set high flow rate, e.g., above 15 L / min. During pressure therapy, the flow generator 11 is operated to provide the user with a set pressure, for example, inspiratory pressure, expiratory pressure, or a constant pressure. Additionally, in the therapy mode, the controller 14 operates the heater plate 121 at one or more therapy power levels to provide an appropriately humidified flow of gases along a gases flow path to the user for respiratory therapy. For the user’s comfort, high flow therapy requires that gases of high humidity (e.g., generally 37 degrees Celsius dew point or 44 mg of absolute humidity) be provided by an unsealed patient interface 30, such as a nasal cannula.

[0299] In addition to the therapy mode, the controller 14 is configured to selectively operate the respiratory apparatus 10 in at least one non-therapy mode. Examples of these non-therapy modes are described below and include a drying mode, a cooling mode, a gas safety mode, and a disinfection mode. However, it will be appreciated that the non-therapy modes could comprise other modes, such as a startup mode in which the controller 14 provides power to the heater plate 121 and / or the heater wire(s) in the heatable breathing conduit 20 to heat the plate and the wire(s) to a target temperature(s) as quickly as possible, or a standby mode in which the controller conserves the amount of power provided to the plate and / or the wire(s) while waiting to receive user instructions. It will also be appreciated that the non-therapy modes could comprise any combination of the described non-therapy modes, including all of them. In one embodiment, the non-therapy modes comprise a cooling mode, a gas safety mode, and a drying mode. In this embodiment, the controller 14 may be configured to operate the respiratory apparatus 10 in the following order: (a) therapy mode; (b) cooling mode; (c) gas safety mode; (d) cooling mode; and (e) drying mode. Alternatively, the controller 14 may be configured to operate the respiratory apparatus 10 in the following order: (a) therapy mode; (b) cooling mode; (c) drying mode; (d) gas safety mode; and (e) drying mode. In another embodiment, the non-therapy modes comprise a cooling mode, a drying mode, a gas safety mode, and a disinfection mode. Non-limiting examples of several non-therapy modes will now be described in detail.

[0300] 2.2 Drying Mode

[0301] The term ‘drying mode’, as used throughout this specification, refers to the controller 14 operating the flow generator 11 according to a drying flow rate and / or the heater plate 121 at no power or to a controller power level (such as a low power level) to dry at least a portion of the gases flow path (e.g., the breathing conduit 20 and / or other gas flow paths like the chamber 120 of the humidifier 12) without generating humidity. Optionally, where the breathing conduit 20 includes one or more heater wires, the controller may be configured to provide a predefined power level (such as full power or substantially full or high power) to the heater wire(s) to dry the gases within the conduit. The term ‘drying mode’ may comprise more than one type of drying mode, in which case, unless otherwise specified, the term ‘drying mode’ refers to any one of the drying modes.

[0302] In one embodiment, the term ‘drying mode’ comprises a maximum drying mode that aims to dry at least a portion of the gases flow path as quickly as possible. In this drying mode, the drying flow rate is consistently the maximum flow rate that can be produced by the flow generator 11 and may run for a set period, e.g., 30 to 45 minutes. In another embodiment, the term ‘drying mode’ comprises a background drying mode. In this drying mode, which saves power and reduces energy consumption compared with the maximum drying mode (which can be especially important in a homecare environment where the user pays for electricity usage), the drying flow rate is a constant rate of between 10 to 16 L / min, which can either be fixed or dynamically adjusted, typically remaining at or below 15 L / min or a motor speed at or under 3,000 revolutions per minute (RPM). The background drying mode is also quiet and, therefore, less likely to wake the user or other people sleeping at night. In yet another embodiment, the term ‘drying mode’ comprises a smart drying mode, which can stop the drying mode early if it is no longer needed, in which the drying flow rate gradually decreases or ramps down over time, for example, at a rate that is proportional to the decreasing temperature of the heater plate 121. Optionally, like the background drying mode, the smart drying mode can also be quiet to avoid disturbing the user or other household occupants.

[0303] The controller 14 may be configured to operate the respiratory apparatus 10 in a drying mode, e.g., after and / or at the conclusion of the therapy mode and optionally for a predetermined duration, e.g., 90 minutes or less. In one embodiment, the controller 14 is configured to operate the respiratory apparatus 10 in the drying mode based on user input relating to the manual initiation of the drying mode after the conclusion of the therapy mode, e.g., via a user interface of the display and I / O 142. In the drying mode, the controller 14 may be configured to operate the flow generator 11 according to one or more drying flow rates, e.g., according to a constant rate or one or more predetermined profiles or functions. The drying flow rate(s) may be less than or greater than the therapy flow rate. The controller 14 may also be configured to operate the heater plate 121 at either no power or a controller power level to dry at least a portion of the gases flow path to the user. For example, the controller power level may be sufficiently low such that no more than a negligible portion of the flow of gases along the gases flow path to the user is humidified.

[0304] In an embodiment where the drying mode is the maximum drying mode, the drying flow rate is consistently the maximum flow rate that can be produced by the respiratory apparatus 10. The controller 14 may be configured to supply no power to the heater plate 121 and maximum power to the heater wire(s) in the heatable breathing conduit 20. The controller 14 may be configured to receive or determine humidifier temperature data indicative or representative of a temperature of or relating to the humidifier 12, compare the humidifier temperature data to one or more safety thresholds (e.g., 50 to 55 degrees Celsius) when the respiratory apparatus 10 is operated in the drying mode, and end the drying mode based on the comparison indicating that the temperature of or relating to the humidifier is less than one or more of the safety thresholds. The controller 14 may be configured to end the drying mode based on the comparison indicating that the temperature of or relating to the humidifier 12 is continuously less than one or more of the safety thresholds for a predetermined duration. The respiratory apparatus 10 may include one or more sensors configured to generate the humidifier temperature data or information for use in deducing the humidifier temperature data. The temperature of the heater plate 121 may be measured as an indication of the temperature of the humidifier 12.

[0305] In an embodiment where the drying mode is the background drying mode, the drying flow rate comprises a constant rate of between 10 to 16 L / min. The controller 14 may be configured to supply a set power level to the heater wire(s) in the heatable breathing conduit 20, and the drying flow rate is proportionally modulated in response to the temperature of the heater plate 121. The controller 14 may be configured to receive or determine ambient noise data indicative or representative of noise produced by the respiratory apparatus 10, compare the ambient noise data to one or more noise thresholds (e.g., 30 dBA) when the apparatus is operated in the drying mode, and decrease the drying flow rate based on the comparison indicating that the noise produced by the apparatus is greater than one or more of the noise thresholds. The respiratory apparatus 10 may include one or more sensors configured to generate the ambient noise data or information for use in deducing the ambient noise data.

[0306] In an embodiment where the drying mode is the smart drying mode, the drying flow rate decreases over time, e.g., at a rate proportional to the decreasing temperature of the heater plate 121. The controller 10 may be configured to stop the drying mode if any one of the following occurs: (a) water is detected at a gases outlet of a chamber 120 of the humidifier 12; (b) the drying mode has run for a predetermined duration; and (c) no water is detected within a breathing conduit 20. The controller 14 may be configured to monitor the power supplied to the heater wire(s) within the heatable breathing conduit 20 and determine whether the power aligns with a predefined power curve as an indicator of whether the conduit contains moisture. The controller 14 may be configured to receive or determine humidifier temperature data indicative or representative of a temperature of or relating to the humidifier 12, compare the humidifier temperature data to one or more safety thresholds when the respiratory apparatus 10 is operated in the drying mode, and adjust the drying flow rate based on the comparison indicating that the temperature of or relating to the humidifier is less than one or more of the safety thresholds. The controller 14 may be configured to adjust the drying flow rate based on the comparison indicating that the temperature of or relating to the humidifier 12 is continuously less than one or more of the safety thresholds for a predetermined duration. The respiratory apparatus 10 may include one or more sensors configured to generate the humidifier temperature data or information for use in deducing the humidifier temperature data. The temperature of the heater plate 121 may be measured as an indication of the temperature of the humidifier 12. The controller 14 may be configured to receive or determine ambient noise data indicative or representative of noise produced by the respiratory apparatus 10, compare the ambient noise data to one or more noise thresholds (e.g., 30 dBA) when the apparatus is operated in the drying mode, and decrease the drying flow rate based on the comparison indicating that the noise produced by the apparatus is greater than one or more of the noise thresholds. The respiratory apparatus 10 may include one or more sensors configured to generate the ambient noise data or information for use in deducing the ambient noise data.

[0307] In one embodiment, the controller 14 is configured to carry out one or more moisture checks to detect the presence of moisture in the breathing conduit 20, e.g., during the drying mode. In one embodiment, the controller is configured to: a) retrieve at least one first signal associated with or indicative of a gases flow and / or pressure in the breathing conduit; b) determine a measure of at least one first parameter associated with gases flow perturbations and / or pressure perturbations for at least one portion of the retrieved at least one first signal; and c) determine the presence of liquid in the breathing conduit based at least in part on the measure(s) of the at least one first parameter meeting a first threshold. The controller may be configured to operate the drying mode until there is no, or low, moisture detected. The perturbation signal may be compared with a threshold to determine the presence of liquid. The controller may be configured to carry out a frequency analysis on the perturbations to detect the presence of liquid in the breathing conduit.

[0308] At least one moisture check may comprise monitoring the temperature of the heater plate 121 and the input power needed to maintain a set temperature of the heater plate, thereby determining whether the temperature of the heater plate aligns with a power curve. Additionally, at least one moisture check may comprise monitoring the temperature of the heater plate 121 while the heater plate provides a short heat pulse and / or monitoring the temperature of the heatable breathing conduit 20 while the heater wire(s) in the conduit provides a short heat pulse.

[0309] In one embodiment, the respiratory apparatus 10 is connectable to a heatable breathing conduit 20 that forms part of the gases flow path for conveying the humidified flow of gases to the user. The heatable breathing conduit 20 comprises a first end connected or connectable to the gases outlet port 1311 of the respiratory apparatus 10 and a second end connected or connectable to a patient interface 30. In one embodiment, the patient interface 30 includes one or more patient detection sensors configured to monitor the connection status of the user to the patient interface. The controller 14 is configured to receive or determine connection status data from the patient detection sensor(s), the connection status data being indicative of or representative of the user's connection status to the patient interface. The controller 14 is configured to stop the drying mode or prevent the drying mode from being activated if the controller determines, based on the connection status data, that the user is not connected to the patient interface 30. The heatable breathing conduit 20 includes one or more heater wires configured to heat at least a portion of the breathing conduit and the flow of gases conveyed by the breathing conduit based on the controller power applied to the heater wire(s). The controller 14 is configured to provide full power or substantially full or high power to the heater wire(s) such that at least a substantial portion of the flow of gases within the heatable breathing conduit 20 is dried or to heat any liquid in the breathing conduit. The heatable breathing conduit 20 may include one or more temperature sensors 21 for measuring the temperature of the flow of gases, and the power provided to the heater wire(s), which is based on the measured temperature, may be sufficient to increase the temperature of the heater wire(s) to be above the temperature measured by the temperature sensor(s), e.g., a predefined power profile.

[0310] The controller 14 is configured to receive or determine oxygen concentration data indicative or representative of a concentration of oxygen in the flow of gases. In one embodiment, the sensor module 1112 of the respiratory apparatus 10 includes one or more ultrasound or ultrasonic gas concentration sensors configured to generate the oxygen concentration data or information for deducing the oxygen concentration data. The information for use in deducing the oxygen concentration data can comprise one or more measurements of characteristics of the flow of gases. These measurements can be taken continuously or with very little delay, e.g., every few milliseconds with every three clock cycles. For example, the measurement(s) may comprise the change in the wavelength of sound through the flow of gases or a rate of the flow of gases and a rate of a flow of oxygen into the flow of gases. One or more sensors in the sensor module 1112 may be configured to measure the flow rate of the flow of gases and the flow rate of supplemental oxygen provided into the gases flow path, e.g., the sensor(s) are positioned in line with the flow of gases. The controller 14 compares the oxygen concentration data to one or more safety thresholds when the respiratory apparatus 10 is operated in or transitioning to the drying mode. For example, the gas safety threshold(s) could comprise a pre-set value against which the oxygen concentration data is compared or a time-based threshold, e.g., the percentage of oxygen in the flow of gases is greater than 25% for two minutes or more. The comparison carried out by the controller 14 could also comprise assessing the oxygen concentration data against the safety threshold(s) for a time-based threshold. The controller 14 will switch the operation of the respiratory apparatus 10 to a gas safety mode based on the comparison indicating that the oxygen concentration in the flow of gases to the user exceeds one or more of the safety thresholds. For example, the controller 14 may be configured to switch the operation of the respiratory apparatus 10 to the gas safety mode or shut off an oxygen supply based on the comparison indicating that the oxygen concentration in the flow of gases continuously exceeds one or more of the safety thresholds for a predetermined duration. The controller 14 may also be configured to continue to operate the respiratory apparatus 10 in the drying mode while the comparison indicates that the concentration of oxygen in the flow of gases does not exceed the safety threshold(s).

[0311] 2.3 Cooling Mode

[0312] The term ‘cooling mode’, as used throughout this specification, refers to the controller 14 operating the flow generator 11 according to a cooling flow rate and / or the heater plate 121 to a controlled power level to cool at least a portion of the gases flow path. The term ‘cooling mode’ may comprise more than one type of cooling mode, in which case, unless otherwise specified, the term ‘cooling mode’ refers to any one of the cooling modes.

[0313] The controller 14 may be configured to operate the respiratory apparatus 10 in a cooling mode to cool the heater plate 121 and / or other components of the humidifier 12, e.g., after and / or at the conclusion of the therapy mode and before or after the drying mode, and optionally for a predetermined duration. For example, the controller 14 can be configured to detect the conclusion of the therapy mode based on user input relating to the manual termination of the therapy mode. Alternatively, the controller 14 can be configured to detect the conclusion of the therapy mode based on a disconnection of a patient interface 30 for a predetermined duration. In the cooling mode, the controller 14 is configured to operate the flow generator 11 according to one or more cooling flow rates and / or the heater plate 121 to a controlled power level to cool at least a portion of the gases flow path. The heater plate 121 can be controlled to no power or low power during the cooling mode to reduce the risk of the user’s hands being burnt when touching the chamber 120 of the humidifier 12 on the heater plate. The cooling flow rate can be greater than or equal to the therapy flow rate.

[0314] The cooling flow rate(s) may be a constant flow rate (e.g., a value between 15 to 30 L / min) or a constant motor speed of the flow generator 11. Alternatively, the cooling flow rate(s) may be provided at a flow profile to reduce the loading on the components of the flow generator 11, e.g., a flow profile may comprise the maximum flow rate or maximum flow generator motor speed for a first predetermined duration followed by half the maximum flow rate or half the maximum flow generator motor speed for a second predetermined duration before repeating.

[0315] The cooling flow rate(s) may also be based on a measured ambient temperature. For example, a cooler ambient temperature may only need a lower cooling flow rate as cooler air is blown across the chamber 120 by the flow generator 11. The cooling flow rate(s) is preferably above a minimum threshold level (e.g., above 25 L / min) or above a minimum flow generator motor speed. However, the cooling flow rate(s) can still be proportional to or a function of the ambient temperature.

[0316] In one embodiment, the respiratory apparatus 10 is connectable to a heatable breathing conduit 20 (e.g., a heatable inspiratory tube that carries one or more breathable gases without allowing water vapour to escape) that forms part of the gases flow path for conveying the humidified flow of gases to the user. The heatable breathing conduit 20 comprises a first end connected or connectable to the gases outlet port 1311 of the respiratory apparatus 10 and a second end connected or connectable to a patient interface 30. The second end of the breathing conduit 20 includes one or more temperature sensors and the controller 14 is configured to operate the respiratory apparatus 10 in the cooling mode after operating the apparatus in the drying mode and / or at the conclusion of the drying mode until the measured temperature at the second end of the breathing conduit is less than ambient temperature or less than 25 degrees Celsius. In one embodiment, the gases outlet of the humidification chamber 120 and the second end of the breathing conduit 20 both contain one or more temperature sensors. The heatable breathing conduit 20 includes one or more heater wires configured to heat at least a portion of the breathing conduit and the flow of gases conveyed by the breathing conduit based on the controller power applied to the heater wire(s).

[0317] The controller power level can be no power or a low power level such that no more than a negligible portion of the flow of gases along the gases flow path to the user is humidified. Advantageously, to prevent condensation from forming in the breathing conduit 20 and increasing the drying time, the power provided to the heater wire(s) is sufficient to ensure that the second end of the breathing conduit 20 is maintained at a predetermined temperature.

[0318] The power provided to the heater wire(s) can be a constant power level or a predefined power profile. The first end of the breathing conduit 20 is connected to a gases outlet of the chamber 120 of the humidifier 12, and the power provided to the heater wire(s) is sufficient to ensure that the temperature at the second end of the breathing conduit is 1 to 5 degrees Celsius greater than the temperature at the gases outlet of the chamber. The temperature of the gases outlet can be measured using the temperature sensor(s) and the temperature at the second end of the breathing conduit 20 can be pre-set, e.g., to 37 degrees Celsius, so that the heater wire(s) are controlled to maintain this set temperature at the second end of the breathing conduit to reduce the chances of condensate forming in the conduit. In one embodiment, the controller 14 is configured to receive or determine humidifier temperature data indicative or representative of a temperature of or relating to the humidifier 12, compare the humidifier temperature data to one or more safety thresholds when the respiratory apparatus 10 is operated in the therapy mode or operated in or transitioning to the cooling mode, and switch operation of the respiratory apparatus to the drying mode or the cooling mode based on the comparison indicating that the temperature of or relating to the humidifier is less than one or more of the safety thresholds, e.g., less than 50 to 55 degrees Celsius. The controller 14 may be configured to switch operation of the apparatus 10 to the drying mode after operating the apparatus in the cooling mode and / or at the conclusion of the cooling mode. The controller 14 may also be configured to switch operation of the respiratory apparatus 10 to the drying mode or the cooling mode based on the comparison indicating that the temperature of or relating to the humidifier 12 is continuously less than one or more of the safety thresholds for a predetermined duration. The controller 14 may also be configured to change the cooling flow rate(s) based on the comparison, e.g., the flow profile may comprise maximum flow rate or maximum flow generator motor speed until the comparison indicates that the temperature of or relating to the humidifier 12 is less than a first safety threshold (e.g., a pre-set percentage above 50 to 55 degrees Celsius) followed by half the maximum flow rate or half the maximum flow generator motor speed until the comparison indicates that the temperature of or relating to the humidifier 12 is less than a second safety threshold, e.g., 50 to 55 degrees Celsius.

[0319] The respiratory apparatus 10 may include one or more sensors configured to generate the humidifier temperature data or information for use in deducing the humidifier temperature data. The temperature of the heater plate 121 can be measured as an indication of the temperature of the humidifier 12, e.g., using one or more heater plate temperature sensors. Alternatively, in another embodiment, the controller 14 may be configured to operate the respiratory apparatus 10 in the cooling mode after operating the apparatus in the drying mode and / or at the conclusion of the drying mode. 2.4 Gas Safety Mode

[0320] The respiratory apparatus 10 may be configured to be operationally connected to at least one source of oxygen for blending with the flow of gases, e.g., an oxygen source connected to the inlet module 110 of the apparatus. To reduce the likelihood of a user forgetting to switch off the oxygen source(s) in a non-therapy mode, thereby creating a fire risk and wasting expensive oxygen, at least one of the sources of oxygen is connected to the respiratory apparatus 10 via a controllable proportional valve 1105 configured to control the flow rate of oxygen entering the apparatus from the oxygen source, e.g., a solenoid valve.

[0321] In a gas safety mode, the controller 14 may be configured to control the valve 1105 to prevent oxygen from entering the respiratory apparatus 10 from the oxygen source when operating in the gas safety mode. For example, the controller 14 can be configured to automatically close the valve 1105 based on the comparison by the controller indicating that the oxygen concentration in the flow of gases exceeds one or more of the safety thresholds. Alternatively, the controller 14 can be configured to prompt the user to manually close the valve 1105 or otherwise switch off the supply from the oxygen source(s) when the comparison indicates that the oxygen concentration in the flow of gases exceeds one or more of the safety thresholds, e.g., in an embodiment in which the valve 1105 is not present. For example, the controller 14 can be configured to trigger or generate an alert, alarm, and / or notification to prompt the user to switch off the oxygen source(s) based at least partly on determining that the oxygen concentration in the flow of gases exceeds one or more of the safety thresholds. The safety threshold(s) may comprise a pre-set value against which the oxygen concentration data is compared or a time-based threshold. The comparison carried out by the controller 14 could also comprise assessing the oxygen concentration data against the safety threshold(s) for a time-based threshold. The oxygen concentration may be measured by an ultrasound or ultrasonic gas concentration sensor. The controller 14 may be configured to generate the alert, alarm, and / or notification in a form selected from any one or more of the following: audible, visual, and / or tactile. For example, in an embodiment in which the respiratory apparatus 10 further comprises an audio output device in electrical communication with the controller 14, the controller may be configured to generate the alert, alarm, and / or notification audibly via the audio output device. Similarly, in an embodiment in which the respiratory apparatus 10 further comprises a display screen in electrical communication with the controller 14, the controller may be configured to generate the alert, alarm, and / or notification visually via the display screen. The controller 14 could also be configured to send or transmit data representing the alert, alarm, and / or notification to a remote device or system in data communication with the respiratory apparatus 10, e.g., a patient and / or device management system, and / or a portable electronic device such as smartphone, tablet, laptop, wearable smart device, or the like. In one embodiment, the controller 14 is configured to: compare the oxygen concentration data to one or more safety thresholds when the respiratory apparatus 10 is operated in or transitioning to the cooling mode; and switch operation of the apparatus to the gas safety mode or shut off an oxygen supply based on the comparison indicating that the concentration of oxygen in the flow of gases to the user exceeds one or more of the safety thresholds.

[0322] To further reduce the fire risk, when the respiratory apparatus 10 is operated in the gas safety mode, the controller 14 may advantageously be configured to provide no power or low power (e.g., below 5 W and, preferably, below 2 W) to the heater wire(s) of the heatable breathing conduit 20 and / or the heater plate 121. The controller 14 may also be configured to operate the flow generator 11 at one or more flushing flow rates to flush the gases flow path, e.g., using ambient air at a constant flushing flow rate to push out the oxygen. When the flow generator 11 is operated at the flushing flow rate(s), the heater wire(s) of the heatable breathing conduit 20 and / or the heater plate 121 may still be provided with no power or low power. Alternatively, to reduce the formation of condensation in the breathing conduit 20, as described above for the cooling mode, the power provided to the heater wire(s) may be sufficient to ensure that the temperature at the second end of the breathing conduit is 1 to 5 degrees Celsius greater than the temperature at the gases outlet of the chamber 120 of the humidifier 12. If condensate does occur, the respiratory apparatus 10 can be operated in the drying mode.

[0323] The flushing flow rate(s) used to flush any oxygen out of the respiratory apparatus 10 may be sufficiently high that any supplemental oxygen is flushed from the gases flow path of the respiratory apparatus 10, e.g., a constant flushing flow rate of at least 10 L / min and, preferably, at least 15 L / min depending on the speed of the motor in the flow generator 11. In one embodiment, the controller 14 may be configured to operate the flow generator 11 at the or each flushing flow rate automatically based on the comparison by the controller indicating that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds. In another embodiment, the controller 14 is configured to operate the flow generator 11 at the or each flushing flow rate based on user input relating to the manual initiation of a flushing flow, e.g., via the user interface of the display and I / O 142. In one embodiment, the controller 14 is configured to operate the flow generator 11 at the or each flushing flow rate for a predetermined duration. In another embodiment, the controller 14 is configured to operate the flow generator 11 at the or each flushing flow rate for a predetermined duration. In another embodiment, the controller 14 is configured to operate the flow generator 11 at the or each flushing flow rate until the concentration of oxygen in the flow of gases is less than or equal to one or more of the safety thresholds. The safety threshold(s) may comprise a pre-set value against which the oxygen concentration data is compared or a time-based threshold. The comparison carried out by the controller 14 could also comprise assessing the oxygen concentration data against the safety threshold(s) for a time-based threshold.

[0324] In an embodiment in which the non-therapy modes comprise a gas safety mode and a cooling mode, and the respiratory apparatus 10 has been operated in the gas safety mode after being operated in the cooling mode, the controller 14 may be configured to switch operation of the apparatus from the gas safety mode back to the cooling mode. In another embodiment in which the non-therapy modes comprise a gas safety mode and a drying mode, and the respiratory apparatus 10 has been operated in the gas safety mode after being operated in the drying mode, the controller 14 may be configured to switch operation of the apparatus from the gas safety mode back to the drying mode.

[0325] 2.5 Disinfection Mode

[0326] The controller 14 may be configured to operate the respiratory apparatus 10 in a disinfection mode. When the respiratory apparatus 10 is operated in the disinfection mode, the controller 14 is configured to measure the oxygen concentration in the flow of gases to the user and, if the concentration of oxygen exceeds one or more safety thresholds, operate the flow generator 11 at one or more flushing flow rate(s) to flush the gases flow path. The flushing flow rate(s) may be sufficiently high that any supplemental oxygen is flushed from the gases flow path of the respiratory apparatus 10, e.g., at least 10 L / min and, preferably, at least 15 L / min. In one embodiment, the controller 14 may be configured to operate the flow generator 11 at the or each flushing flow rate automatically based on the comparison by the controller indicating that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds. In another embodiment, the controller 14 is configured to operate the flow generator 11 at the or each flushing flow rate based on user input relating to the manual initiation of a flushing flow, e.g., via the user interface of the display and I / O 142. In one embodiment, the controller 14 is configured to operate the flow generator 11 at the or each flushing flow rate for a predetermined duration. In another embodiment, the controller 14 is configured to operate the flow generator 11 at the or each flushing flow rate until the concentration of oxygen in the flow of gases is less than or equal to one or more safety thresholds. In the disinfection mode, the controller 14 may be configured to operate the heater plate 121 and / or the or any heater wire(s) of the or any heatable breathing conduit 20 to be controlled to no power or low power when the flow generator 11 is operated at the flushing flow rate(s). 3. Example Embodiments of Respiratory Apparatuses

[0327] Example embodiments of the respiratory apparatus 10 will be described in which the apparatus is configured to selectively operate in a therapy mode and at least one nontherapy mode as set out above. It will be appreciated that these examples are selected only for the purposes of illustration of safety improvements and should not be interpreted as limiting this disclosure. It will be particularly appreciated that the non-therapy modes could comprise any one or more of the four non-therapy modes as set out above, including all four of the non-therapy modes, as well as other non-therapy modes.

[0328] 3.1 First Example Embodiment of Respiratory Apparatus

[0329] A first exemplary embodiment of the respiratory apparatus 10 will now be described. In this embodiment, the apparatus is configured to detect whether the oxygen source(s) have been switched off by the user following a therapy mode and, if not, prompt the user to switch off the oxygen source(s) and / or turn off power to the heater wire(s) of the heatable breathing conduit 20 and the heater plate 121 to reduce the risk of fire. Although providing no power to the heater wire(s) and / or the heater plate 121 is advantageous in reducing the fire risk, it will be appreciated that the fire risk will still be reduced if the heater wire(s) and / or the heater plate 121 are provided with low power (i.e., a small amount of power, e.g., less than 5 W and, preferably, less than 2 W) rather than no power. In addition to the therapy mode, the respiratory apparatus 10 is configured to selectively operate in one of a plurality of non-therapy modes comprising at least a drying mode and a gas safety mode as set out above. The drying mode may be automatically started after or at the conclusion of the therapy mode or be manually initiated by the user.

[0330] The controller 14 is configured to receive or determine oxygen concentration data indicative or representative of a concentration of oxygen in the flow of gases generated by the flow generator 11 for the user. The controller 14 compares the oxygen concentration data to one or more safety thresholds when the respiratory apparatus 10 is operated in or transitioning to the drying mode. The controller 14 then switches the operation of the respiratory apparatus 10 to the gas safety mode or shut off an oxygen supply based on the comparison indicating that the concentration of oxygen in the flow of gases to the user exceeds one or more of the safety thresholds e.g., the percentage of oxygen in the flow of gases is greater than 25% for two minutes or more. The respiratory apparatus 10 includes one or more oxygen concentration sensors configured to generate the oxygen concentration data or information for use in deducing the oxygen concentration data, e.g., a fuel cell type sensor or, preferably, an ultrasound or ultrasonic gas concentration sensor to detect the speed of sound through the gases. The controller 14 and / or the oxygen concentration sensor(s) can calculate or deduce the oxygen concentration in the flow of gases based on the sensor readings. Alternatively, the controller 14 and / or the oxygen concentration sensor(s) may calculate or deduce the oxygen concentration in the flow of gases based on the set flow rate and the input oxygen flow rate from the oxygen source(s).

[0331] The purpose of the drying mode is to dry or clear moisture from at least a portion of the gases flow path. The drying mode either initiates automatically at or after completion of the therapy mode or is triggered by user input, e.g., when the user presses an OFF button to end the therapy mode. If the heater plate 121 was activated during the therapy mode, the initiated or triggered drying mode may be the background drying mode. However, if the heater plate 121 was not activated during the therapy mode, the initiated or triggered drying mode may be the smart drying mode as part of a shutdown procedure.

[0332] 3.1.1 Maximum Drying Mode

[0333] Referring to the flow chart of Figure 8, a maximum drying mode 200 will now be described in which the controller 14 is configured to carry out the following steps. First, in step 201, the controller starts to operate the respiratory apparatus 10 in the maximum drying mode, e.g., at or after the completion of the therapy mode, and optionally for a set period, e.g., 30 to 60 minutes. To dry at least a portion of the gases flow path as quickly as possible, the controller 14 regulates the motor speed of the flow generator 11 to operate the flow generator 11 at a constant maximum speed to push air through the heatable breathing conduit 20 for drying. During the maximum drying mode, no power is supplied to the heater plate 121 and maximum power is supplied to the heater wire(s) in the breathing conduit 20 to heat the airflow and assist in moisture evaporation. At step 202, the temperature of the heater plate 121 is measured using one or more heater plate temperature sensors to indicate the temperature of the chamber 120 of the humidifier 12 (the temperature of the heater plate 121 being a proxy for the temperature of the chamber 120) and, at step 203, this humidifier temperature data is compared to one or more safety thresholds, e.g., 50 to 55 degrees Celsius, to prevent any bums to the user when touching the chamber. If the humidifier temperature data indicates that the temperature of the chamber 120 is not continuously less than the threshold(s) for a predetermined duration, the maximum drying mode is continued at step 204, e.g., for 30 to 60 minutes to ensure that the breathing conduit 20 is dry.

[0334] The controller 14 carries out a moisture check at step 207 to determine whether there is any water in the humidification chamber 120. At step 206, the temperature of the heater plate 121 and the input power needed to maintain a set temperature are monitored to determine whether the heater plate’s temperature aligns with a power curve. If water is present in the humidification chamber 120, the temperature of the heater plate 121 rises slowly while the power input remains high to maintain a set temperature, and the power profile flattens. If no or minimal water is present in the humidification chamber 120, the temperature of the heater plate 121 suddenly rises and the required power input drops. If moisture is still present, at step 207, the controller 14 reduces the power supplied to the heater wire(s) of the heatable breathing conduit 20 (e.g., to 60-70% of maximum power) and / or reduces the drying flow rate while monitoring continues until a predetermined duration (e.g., 5 to 10 minutes) has expired. However, if no moisture is detected, at steps 208 and 209, the controller 14 switches the operation of the respiratory apparatus 10 from the maximum drying mode to the background drying mode for a predetermined duration (e.g., 5 to 10 minutes) to safely cool the heater plate 121 and the breathing conduit 20, ensuring that no residual moisture remains.

[0335] However, if the humidifier temperature data indicates that the temperature of the chamber 120 is continuously less than the threshold(s) for a predetermined duration, indicating that the breathing conduit 20 is dry, the controller 14 will automatically cease the maximum drying mode at step 210. This provides a quicker drying process than one that runs the drying mode for a predetermined time duration.

[0336] 3.1.2 Background Drying Mode

[0337] Referring to the flow chart of Figure 9, a background drying mode process 300 will now be described in which the controller 14 is configured to carry out the following steps. First, in step 301, the controller 14 starts to operate the respiratory apparatus 10 in the background drying mode, e.g., at the completion of the therapy mode or after a subsequent cooling mode has reduced the temperature of the heater plate 121 to below 50 to 55 degrees Celsius. At steps 302 and 303, the controller 14 regulates the motor speed of the flow generator 11 to operate the flow generator 11 at a constant drying flow rate of between 10 to 16 L / min. This drying flow rate can be either fixed or dynamically adjusted, typically remaining below 15 L / min or a motor speed of, for example, under 3,000 RPM. A microphone sensor positioned adjacent to the flow generator 11 may be used to measure the sound generated by the flow generator, and the controller 14 may adjust the motor speed and, therefore, the drying flow rate to ensure that the noise from the flow generator does not exceed a predetermined threshold, e.g., 30 dBA. This reduces noise in the user’s house and reduces disturbance to the user.

[0338] The respiratory apparatus 10 may be connectable to a heatable breathing conduit 20, and, at step 304, the controller 14 operates the heater wire(s) of the conduit at a set power level (e.g., more than 20% of maximum power), with the drying flow rate proportionally modulated in response to the temperature of the heater plate 121. At step 305, the controller 14 supplies power to the heater wire(s) to a low power level to lower the heating rate of the gases in the conduit 20. The temperature of the heater wire(s) is dependent on the temperature needed to stop condensate in the conduit 20. At step 306, the controller 14 determines whether the background drying mode has run for a predetermined duration, e.g., 99 minutes. If not, at step 307, the background drying mode continues. However, if the predetermined length of time has been reached, at step 308, the background drying mode ends. The respiratory apparatus 10 may then enter a standby mode for a set duration before powering down.

[0339] 3.1.3 Smart Drying Mode

[0340] Operating the drying mode for longer than is necessary is inefficient in terms of time and power consumption. The smart mode uses intelligence to end the drying mode early if the drying mode is no longer needed. To reduce power consumption and improve efficiency, fan speed and power to the heater wire(s) can be dynamically adjusted as moisture levels and air temperature change, since the initial settings at the start of the drying mode may no longer be optimal. Smart control is enabled through real-time sensor readings, allowing the controller 14 to continuously reassess and adapt. For example, if humidity drops rapidly, the fan speed in the flow generator 11 is reduced to lower noise and conserve energy. If the temperature rises, the power to the heater wire(s) is reduced or pulsed to prevent overheating. If the flow resistance increases, the fan power is slightly increased to maintain consistent airflow. Additionally, the drying mode should preferably continue only as needed to conserve power, rather than run for a predetermined duration regardless of need. The smart drying mode balances drying effectiveness with power efficiency and noise control by adjusting the fan and heater wire(s) outputs based on realtime conditions, i.e., moisture, airflow resistance, and ambient temperature.

[0341] Referring to the flow chart of Figure 10, a smart drying mode process 400 will now be described in which the controller 14 is configured to carry out the following steps. First, in step 401, the controller starts to operate the respiratory apparatus 10 in the smart drying mode, e.g., at or after the completion of the therapy mode. During the smart drying mode, the controller 14 switches off power to the heater plate 121 and provides power to the heater wire(s) in the heatable breathing conduit 20, for example, 50% or 100% of maximum power by voltage control or duty cycle. At optional step 402, the temperature of the heater plate 121 is measured using one or more heater plate temperature sensors to indicate the temperature of the chamber 120 of the humidifier 12 and this humidifier temperature data is compared to one or more safety thresholds, e.g., 50 to 55 degrees Celsius. If the humidifier temperature data indicates that the temperature of the chamber 120 is not continuously less than the threshold(s) for a predetermined duration, the controller 14 will switch the operation of the respiratory apparatus 10 from the smart drying mode to the cooling mode at step 403. However, if the humidifier temperature data indicates that the temperature of the chamber 120 is continuously less than the threshold(s) for a predetermined duration, the flow generator 11 is operated at its maximum flow rate at step 404. At steps 405 and 406, the controller 14 determines whether one or more stop conditions have occurred. The first stop condition is whether the smart drying mode has run for a predetermined duration at step 407. If so, smart drying mode will end at step 408. If not, the smart drying mode continues. The second stop condition is whether the power supplied to the heater wire(s) within the heatable breathing conduit 20 follows a predefined power curve (which indicates that no moisture is contained within the breathing conduit 20) at step 409. If the power curve is followed, then the smart drying mode will end at step 410. However, if the power curve deviates, this is an indication that there is still moisture in the breathing conduit 20 and the smart drying mode continues. The third stop condition is whether the heating rate of the heater plate 121 is greater than a threshold value (which also indicates that no moisture is contained within the breathing conduit 20). To check for the third stop condition, the controller 14 measures the temperature of the heater plate 121 at step 411, provides a short pulse of power to the heater plate at step 412, measures the heating rate of the heater plate for a predetermined duration at step 413, and determines whether the heating rate is greater than a threshold value at step 414. If so, smart drying mode will end at step 415. If not, the smart drying mode continues. 3.1.4 Moisture Detection Process

[0342] The smart drying mode described above is designed to operate the drying only when necessary. The selective use of the smart drying mode is triggered by the detection of moisture in the breathing conduit 20 after the therapy mode, at which point the controller 14 logs this event and enables all required sensors. To detect moisture in the breathing conduit 20, the controller 14 is configured to: a) retrieve at least one first signal associated with or indicative of a gases flow and / or pressure in the conduit; b) determine a measure of at least one first parameter associated with gases flow perturbations and / or pressure perturbations for at least one portion of the retrieved at least one first signal; and c) determine the presence of liquid in the conduit based at least in part on the measure(s) of the at least one first parameter meeting a first threshold. The drying mode may be operated until there is no, or low, moisture detected. The perturbation signal may be compared with a threshold e.g., the amplitude and / or frequency can be compared with a threshold to determine the presence of liquid. Alternatively, a frequency analysis may be done on the perturbations to detect the presence of liquid in the breathing conduit 20. The methods of moisture detection can include those disclosed in USSN 17 / 309,337, filed on 19 May 2021 and published as U.S. Patent Application No. 2022 / 0031987, which is incorporated herein by reference in its entirety.

[0343] Referring to the flow chart of Figure 11, a moisture detection process 500 for the heatable breathing conduit 20 will now be described in which the controller 14 is configured to carry out the following steps. First, in step 501, the controller starts to operate the respiratory apparatus 10 in the smart drying mode. At step 502, the controller 14 regulates the motor speed of the flow generator 11 to operate the flow generator 11 at an initially high drying flow rate (e.g., with the fan of the flow generator spinning at its maximum revolutions per minute) and to supply the heater wire(s) in the heatable breathing conduit 20 with a high-power level (e.g., 80-100% of maximum power) to quickly evaporate the bulk of any residual moisture in the conduit. The controller 14 carries out a moisture check at step 503 to detect the presence of any remaining moisture in the breathing conduit 20. At step 503, the power supplied to the heater plate 121 rises quickly (e.g., from 70% to 100% power) to provide a short heat pulse while the temperature of the heater plate is monitored. If the temperature of the heater plate 121 rises quickly, then no water remains. However, if the temperature rise is dampened, then water is still present. Based on the one or both moisture checks, the controller 14 determines, at step 504, whether moisture is still detected in the breathing conduit 20. If moisture is still detected, at step 505, the controller 14 reduces the power supplied to the heater wire(s) of the heatable breathing conduit 20 (e.g., to 60-70% of maximum power) and / or reduces the drying flow rate while monitoring continues until a predetermined duration (e.g., 5 to 10 minutes) has expired. However, if no moisture is detected, at steps 506 and 507, the controller 14 switches the operation of the respiratory apparatus 10 from the smart drying mode to the background drying mode for a predetermined duration (e.g., 5 to 10 minutes) to safely cool the heater plate 121 and the breathing conduit 20, ensuring that no residual moisture remains.

[0344] Optionally, during the background drying mode, the controller 14 regulates the motor speed of the flow generator 11 to operate the flow generator 11 at a fixed drying flow rate of less than 15 L / min or a motor speed of less than 3,000 RPM and either provides no power or pulses of up to 20% of maximum power to the heater plate 121 to maintain a dry flow of gases to the user. Finally, at step 508, the background drying mode is stopped after the predetermined duration has expired, and the controller 14 has analysed power and temperature response signatures. If airflow and temperature have stabilised and no moisture is detected, the drying mode is marked complete, and the user is notified. The respiratory apparatus 10 can then turn off the heater wire(s) and the flow generator 11, and power down. 3.1.5 Patient Detection Process

[0345] Referring to the flow chart of Figure 12, a patient detection process 600 will now be described in which the controller 14 is configured to carry out the following steps continuously or at regular intervals during any of the drying modes. First, in step 601, the controller initiates the patient detection process, e.g., upon completion of the therapy mode, to prevent activation of the drying mode and a bum risk to the user while the user remains connected to the patient interface 30. At step 602, the connection status of the user to the patient interface 30 is continuously monitored using one or more patient detection sensors embedded in the patient interface, e.g., one or more pressure sensors. At step 603, this connection status data is sent in real time to the controller 14, enabling a dynamic assessment of whether the user is connected to the patient interface 30. At step 604, the controller 14 determines whether the user is connected to the patient interface 30, for example, by comparing the connection status data against a patient presence threshold. If the controller 14 determines that the user is not connected to the patient interface 30, the controller will allow the drying mode to be activated at step 605. The controller 14 will switch the respiratory apparatus 10 to the drying mode but continue to monitor connection status data and immediately stop the drying mode if the controller determines that the user has reconnected with the patient interface 30 during the drying mode. However, if the controller 14 determines that the user is connected to the patient interface 30, the controller will prevent the drying mode from being activated at step 606 and trigger or generate an alert, alarm, and / or notification to inform the user that the drying mode cannot begin at step 607.

[0346] Referring to the flow chart of Figure 13, a first oxygen safety check process 700 will now be described in which the controller 14 is configured to carry out the following steps. First, in step 701, the controller 14 ends the therapy mode, e.g., based on user input relating to the manual termination of the therapy mode. At steps 702 and 703, the controller 14 compares oxygen concentration or flow rate data gathered from at least one sensor (e.g., an oxygen flow sensor) with one or more safety thresholds. If the comparison indicates that the concentration or flow rate of oxygen in the flow of gases to the user does not continuously exceed one or more of the safety thresholds for a predetermined duration, the controller 14 will, at step 704, switch operation of the respiratory apparatus 10 to the drying mode or the cooling mode. However, if the comparison indicates that the concentration of oxygen in the flow of gases to the user continuously exceeds one or more of the safety thresholds for a predetermined duration, the controller 14 will, at step 705, trigger a safety lock either by sending a signal to the controllable proportional valve 1105 configured to control the flow rate of oxygen entering the apparatus from an oxygen source to automatically close the valve or by cutting the power to an oxygen delivery pump, depending upon the apparatus design. Finally, at step 706, the controller 14 either triggers or generates an alert, alarm, and / or notification, e.g., a message on a display screen, to inform the user of the detection of oxygen and the safety lock or that the drying or cooling mode has started.

[0347] 3.1.7 Oxygen Safety Check Process During Drying Mode

[0348] Referring to the flow chart of Figure 14, a second oxygen safety check process 1000 will now be described in which the controller 14 is configured to carry out the following steps after therapy mode ends and before drying mode starts as well as continuously during any of the drying modes. First, in step 1100, the controller 14 starts to operate the respiratory apparatus 10 in the drying mode, e.g., automatically at the conclusion of the therapy mode or based on user input relating to the manual initiation of the drying mode after the conclusion of the therapy mode. During the drying mode, the heater wire(s) are operated at maximum power to dry the heatable breathing conduit 20, and the heater plate 121 is operated at either no or low power. Secondly, in step 1200, the oxygen concentration sensor(s) generate the oxygen concentration data or information for use in deducing the oxygen concentration data. At step 1300, the controller 14 compares the oxygen concentration data to the safety threshold(s) to determine whether the concentration of oxygen in the flow of gases to the user exceeds the safety threshold(s), e.g., continuously for a predetermined duration.

[0349] If the concentration of oxygen does not exceed the safety threshold(s), the controller 14 continues to operate the respiratory apparatus 10 in the drying mode, at step 1800, while the comparison indicates that the concentration of oxygen in the flow of gases does not exceed the safety threshold(s). However, if the concentration of oxygen does exceed the safety threshold(s), the controller 14 switches the operation of the respiratory apparatus 10 to the gas safety mode or shut off an oxygen supply (e.g., automatically using an interrupt routine) and, at step 1400, triggers or generates an alert, alarm, and / or notification, e.g., a message on a display screen to prompt the user to switch off the oxygen source(s) and / or present a “flush device” option on the display. Optionally, at step 1500, the controller 14 switches off the power to the flow generator 11, the heater wire(s) of the heatable breathing conduit 20 and / or the heater plate 121.

[0350] At step 1600, the controller 14 automatically begins to operate the flow generator 11 at one or more flushing flow rates to flush any supplemental oxygen from the gases flow path, either: (a) based on user input received via a user interface in response to a query or “flush device” option presented to the user on the display; or (b) automatically based on the comparison continuing to indicate that the concentration of oxygen in the flow of gases exceeds the safety threshold(s). Finally, at step 1700, the controller 14 continues to operate the flow generator 11 at the flushing flow rate(s) until the concentration of oxygen in the flow of gases is less than or equal to the safety threshold(s), e.g., continuously below 25% oxygen, and preferably below 22% oxygen, for a predetermined duration, whereupon the controller may automatically resume drying mode or present a query on the user interface asking if the user would like to resume drying mode. During step 1700, no power is provided to the heater plate 121 and / or the heater wire(s) to reduce the fire risk. However, as discussed above, it will be appreciated that, during step 1700, the fire risk would still be reduced if the heater wire(s) and the heater plate 121 were provided with low power rather than no power. Prompting the user to switch off the oxygen source(s) reduces the fire risk caused by oxygen spilling into the room during drying mode and is especially beneficial for a homebased user who is using the respiratory apparatus 10 without the on-site assistance of trained technicians or nurses. In addition, operating the flow generator 11 at the flushing flow rate(s) reduces the chances of oxygen accumulating within the respiratory apparatus 10. Accumulated oxygen presents a fire risk, so flushing it out is advantageous. Finally, switching off or at least reducing the power provided to the heater wire(s) and the heater plate 121 reduces the risk of a fire starting in an oxy gen-enriched environment.

[0351] 3.2 Second Example Embodiment of Respiratory Apparatus

[0352] A second exemplary embodiment of the respiratory apparatus 10 will now be described. In this embodiment, the respiratory apparatus 10 is configured to reduce the burn risk to the user’s hands if the user attempts to remove the humidification chamber 120 from the heater plate 121 of the humidifier 12 at or after the completion of the therapy mode, e.g., to wash or clean the chamber. At the end of a therapy mode, the heater plate 121 and the chamber may be at high temperatures well above the International Electrotechnical Commission (EEC) safety standard of 55 degrees Celsius. IEC or other safety standards specify temperature limits, with 55 degrees Celsius being the maximum allowable safe threshold for a person to hold a hot object for up to a minute without causing physical pain or harm to the person. In addition to the therapy mode, the respiratory apparatus 10 is configured to selectively operate in one of a plurality of non-therapy modes comprising at least a cooling mode and a drying mode as set out above. The controller 14 is configured to detect the conclusion of the therapy mode and operate the respiratory apparatus 10 in the cooling mode at the detected conclusion of the therapy mode to cool the heater plate 121 and / or other components of the humidifier 12, e.g., the chamber 120. Accordingly, the cooling mode can be automatically executed after the therapy mode is finished and before the drying mode is started. The controller 14 is also configured to switch the respiratory apparatus 10 to the drying mode, e.g., after a predetermined duration, after operating the apparatus in the cooling mode, and / or at the conclusion of the cooling mode.

[0353] 3.2.1 Non-Therapy Mode Selection Process

[0354] After the therapy mode has finished, the controller 14 may automatically select whether to switch operation to the cooling mode (such as the fast-cooling mode described below) or the drying mode. Referring to the flow chart of Figure 15, a non-therapy mode selection process 800 will now be described in which the controller 14 is configured to carry out the following steps after operating the apparatus 10 in the therapy mode. First, in step 801, the controller 14 stops operating the respiratory apparatus 10 in the therapy mode. At step 802, the temperature of the heater plate 121 is measured using one or more heater plate sensors to indicate the temperature of the chamber 120 of the humidifier 12. At step 803, this humidifier temperature data is compared to one or more safety standards, e.g., a threshold of 50 to 55 degrees Celsius. If the humidifier temperature data indicates that the temperature of the chamber 120 is continuously greater than the threshold(s) for a predetermined duration, the cooling mode is initiated or continued at step 804. This rapidly lowers the temperature of the chamber 120 to reduce the risk of bums if the user attempts to handle the chamber before it has cooled sufficiently. However, if the humidifier temperature data indicates that the temperature of the chamber 120 is continuously less than the threshold(s) for a predetermined duration, the cooling mode is initiated or continued for a predetermined duration at the same therapeutic flow rate at step 805 before operation of the respiratory apparatus 10 is switched from the cooling mode to the drying mode at step 806. Accordingly, the selection process 800 ensures that the heater plate 121 is cooled using the cooling mode if its temperature exceeds 50 to 55 degrees Celsius, while saving power by not prolonging the cooling mode if the temperature of the heater plate is already below the threshold for a predetermined duration. 3.2.2 Fast-Cooling Mode

[0355] Homecare patients often try and remove the chamber 120 out of the humidifier 12 when the therapy mode has finished. During therapy mode, the chamber 120 can get very hot and, therefore, a cooling mode ensures safety. Referring to the flow chart of Figure 16, a fast-cooling mode process 900 will now be described in which the controller 14 is configured to carry out the following steps after operating the apparatus 10 in the therapy mode. First, in step 901, the controller 14 starts to operate the respiratory apparatus 10 in the fast-cooling mode, e.g., at or after the completion of the therapy mode. At step 902, the controller 14 regulates the motor speed of the flow generator 11 at a cooling flow rate equal to the flow rate during the previous therapy mode. At steps 903 to 905, the controller 14 powers the heater wire(s) in the heatable breathing conduit 20 to maintain the conduit temperature approximately 3 degrees Celsius above ambient, based on readings from a temperature sensor at the patient end of the breathing conduit 20, which measures a temperature higher than either the chamber outlet gas sensor or the heater plate temperature sensor. During the fast-cooling mode, the blower 1111 of the flow generator 11 is activated to draw in ambient air. This air is directed across the surface of the heater plate 121 using internal channels. This airflow aims to reduce the time it takes for the heater plate 121 to cool down. If water is in the chamber 120 of the humidifier 12, the flow of gases entering through the humidification chamber inlet passes over the water. This, in combination with the lack of power to the heater plate 121, is what quickly cools down the water. The heatable breathing conduit 20 is still connected during the fastcooling mode to ensure that residual moisture does not condensate and therefore flow back into the system. The controller 14 maintains the temperature above the dew point to prevent condensation build-up.

[0356] At step 906, the temperature of the heater plate 121 is measured using one or more heater plate temperature sensors to indicate the temperature of the chamber 120 of the humidifier 12, and this humidifier temperature data is compared to one or more safety thresholds, e.g., 50 to 55 degrees Celsius. Alternatively, the temperature of the gases at the outlet of the chamber 120 of the humidifier 12 can be measured using temperature senser 130. If the humidifier temperature data indicates that the temperature of the chamber 120 is not continuously less than the threshold(s) for a predetermined duration, the fast-cooling mode is continued for a predetermined duration before reassessing the situation, as the chamber is not yet safe to handle. However, if the humidifier temperature data indicates that the temperature of the chamber 120 is continuously less than the threshold(s) for a predetermined duration, the chamber is safe to handle, and the controller 14 will alert the user of this at step 907, e.g., through a notification on the interface, before switching the respiratory apparatus 10 to the drying mode at step 908, e.g., maximum drying mode or background drying mode can be programmed by the user to start after therapy mode has concluded. Accordingly, the fast-cooling mode can save power by not running the cooling mode if it is not required to cool the chamber 120.

[0357] 3.2.3 First Example Implementation

[0358] Referring to the flow chart of Figure 17, an example implementation combining cooling mode, oxygen detection, and drying mode will now be described in which the controller 14 is configured to carry out the following steps. First, in step 2000, the controller 14 detects the conclusion of the therapy mode, e.g., based on user input, such as an OFF button being pressed, or if the patient interface 30 is detected as being removed for longer than a threshold time, e.g., 10 minutes. After the conclusion of the therapy mode is detected, in step 210, the controller 14 begins to operate the respiratory apparatus 10 in the cooling mode. In cooling mode, power to the heater plate 121 is preferably turned off in step 2300 (e.g., after a predetermined duration of 5-10 minutes) or at least controlled to low power (i.e., a small amount of power, e.g., less than 5 W and, preferably, less than 2 W). At step 2400, the power provided by the controller 14 to the heater wire(s) of the heatable breathing conduit 20 is advantageously sufficient to ensure that the temperature at the second end or “patient end” of the conduit is 1 to 5 degrees Celsius greater than the temperature at the gases outlet of the chamber 120, as measured by sensors. This is done to prevent condensation from forming in the breathing conduit 20. The power to the heater wire(s) is reduced in proportion to the reduction in the gases outlet temperature of the chamber 120, which is less than 50 degrees Celsius. Alternatively, either a low power (e.g., 10% duty cycle) is applied to the heater wire(s) to reduce condensation formation, or no power is applied to the heater wire(s). At step 2500, the controller 14 controls the flow generator 11 to provide a cooling flow rate to cool at least a portion of the gases flow path to the user. The cooling flow rate could be a set value or the flow generator 11 can be controlled to operate at a constant motor speed, e.g., the maximum speed of the motor in the flow generator. The cooling flow rate could also be dynamic, or the same flow rate used during the therapy mode. At step 2600, the temperature of the heater plate 121 is measured using one or more heater plate temperature sensors to indicate the temperature of the chamber 120 of the humidifier 12. At step 2700, this humidifier temperature data is compared to one or more safety thresholds, e.g., the IEC safety standard of 55 degrees Celsius. If the humidifier temperature data indicates that the temperature of the chamber 120 is not continuously less than the threshold(s) for a predetermined duration, the cooling flow rate is continued. However, if the humidifier temperature data indicates that the temperature of the chamber 120 is continuously less than the threshold(s) for a predetermined duration, operation of the respiratory apparatus 10 is switched from the cooling mode to the drying mode. Alternatively, in place of step 2600 and / or 2700, the cooling flow rate may be continued, at step 2500, for a predetermined duration, e.g., 30-90 minutes.

[0359] The drying mode is initiated at step 2800 in Figure 17. During the drying mode, the controller 14 operates the flow generator 11 at one or more drying flow rates in step 2900 to dry at least a portion of the gases flow path to the user, e.g., a constant flow rate above the therapy flow rate or one based on the maximum motor speed of the controller 14. The drying flow rate could also be dynamic, or the same flow rate used during the therapy mode. Additionally, at step 3000, the controller 14 provides the heater wire(s) of the heatable breathing conduit 20 with full power or substantially full or high power to dry at least a substantial portion of the conduit and heat any liquid in the conduit, causing it to evaporate. The drying mode is then continued for a predetermined duration at step 3100, e.g., 90 minutes or less (while checking for condensate in the breathing conduit 20), before the respiratory apparatus 10 is switched off.

[0360] Optionally, as shown in Figure 17, one of the non-therapy modes may also be the gas safety mode. During the cooling mode and / or the drying mode, the controller 14 may be configured, at step 2200, to compare oxygen concentration data gathered from at least one sensor with one or more safety thresholds, e.g., an oxygen threshold of 20-30%. If the comparison indicates that the concentration of oxygen in the flow of gases to the user continuously exceeds one or more of the safety thresholds for a predetermined duration, the controller 14 will, at step 3200, switch the operation of the respiratory apparatus 10 from the cooling mode or the drying mode to the gas safety mode or shut off an oxygen supply, e.g., using an interrupt routine. The substeps contained in step 3300 of Figure 15 are the same as steps 1400 to 1700 of Figure 12, including triggering or generating an alert, alarm, and / or notification to prompt the user to switch off the oxygen source(s) and / or operating the flow generator 11 at one or more flushing flow rates to flush any supplemental oxygen from the gases flow path until the concentration of oxygen in the flow of gases is less than or equal to the safety threshold(s) for a predetermined duration, whereupon the controller may automatically resume cooling mode or drying mode or present a query on the user interface asking if the user would like to resume cooling mode or drying mode.

[0361] 3.2.4 Second Example Implementation

[0362] Referring to the flow chart of Figure 18, an example implementation 4000 combining cooling mode and drying mode, as well oxygen detection and patient detection will now be described in which the controller 14 is configured to carry out the following steps. First, in step 4100, the controller starts operation of the respiratory apparatus 10 in the cooling mode. At step 4200, the controller 14 compares oxygen concentration or flow rate data gathered from at least one sensor (e.g., an oxygen flow sensor) with one or more safety thresholds. If the comparison indicates that the concentration or flow rate of oxygen in the flow of gases to the user continuously exceeds one or more of the safety thresholds for a predetermined duration, the controller 14 will, at step 4300, stop the cooling mode. At step 4400, the temperature of the heater plate 121 is measured using one or more heater plate temperature sensors to indicate the temperature of the chamber 120 of the humidifier 12, and this humidifier temperature data is compared to one or more safety thresholds, e.g., 50 to 55 degrees Celsius. If the humidifier temperature data indicates that the temperature of the chamber 120 is not continuously less than the threshold(s) for a predetermined duration, the cooling mode is continued for a predetermined duration before reassessing the situation, as the chamber is not yet safe to handle. However, if the humidifier temperature data indicates that the temperature of the chamber 120 is continuously less than the threshold(s) for a predetermined duration, the chamber is safe to handle, and the controller 14 will end the cooling mode and start the drying mode at step 4500. At step 4600, the controller 14 determines whether the user is connected to the patient interface 30, for example, by comparing the connection status data against a patient presence threshold. If the controller 14 determines that the user is connected to the patient interface 30, the controller will stop the drying mode at step 4300. However, if the controller 14 determines that the user is not connected to the patient interface 30, the controller will proceed to carry out another oxygen check at step 4700 before continuing with drying mode at step 4800. Steps 4600 and 4700 may be carried out continuously or at regular intervals during the drying mode.

[0363] 3.3 Third Example Embodiment of Respiratory Apparatus

[0364] A third exemplary embodiment of the respiratory apparatus 10 will now be briefly described. In this embodiment, the respiratory apparatus 10 includes all the features of the first and second embodiments described above and can perform all the processes shown in Figures 8 and 9. Accordingly, the apparatus is configured to selectively operate in a therapy mode or one of a plurality of non-therapy modes, the non-therapy modes comprising at least a drying mode, a gas safety mode, and a cooling mode. The non- therapy modes may also include other modes, such as, a disinfection mode, a startup mode, or a standby mode, etc.

[0365] In this embodiment, the apparatus 10 is configured to use the gas safety mode to reduce the risk of a fire by detecting whether the oxygen source(s) have been switched off by the user following the therapy mode and, if not, promoting the user to do so and / or turning off power to the heater wire(s) of the heatable breathing conduit 20 and the heater plate 121.

[0366] Additionally, the apparatus 10 is configured to use the cooling mode to reduce the bum risk to the user’s hands if the user attempts to remove the humidification chamber 120 from the heater plate 121 of the humidifier 12 at or after the completion of the therapy mode.

[0367] 4. Terminology and Definitions

[0368] The phrases 'computer-readable medium' or ‘machine-readable medium’ as used in this specification and claims should be taken to include, unless the context suggests otherwise, a single medium or multiple media. Examples of multiple media include a centralised or distributed database and / or associated caches. These multiple media store the one or more sets of computer-executable instructions. The phrases 'computer- readable medium' or ‘machine-readable medium’ should also be taken to include any medium that is capable of storing, encoding or carrying a set of instructions for execution by a processor of a computing device and that causes the processor to perform any one or more of the methods described herein. The computer-readable medium is also capable of storing, encoding or carrying data structures used by or associated with these sets of instructions. The phrases 'computer-readable medium' and ‘machine- readable medium’ include, but are not limited to, portable to fixed storage devices, solid-state memories, optical media or optical storage devices, magnetic media, and / or various other mediums capable of storing, containing or carrying instruction(s) and / or data. The ‘computer-readable medium’ or ‘machine-readable medium’ may be non- transitory.

[0369] The term ‘comprising’ as used in this specification and claims means ‘consisting at least in part of or ‘including, but not limited to’ such that it is to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense. When interpreting each statement in this specification and claims that includes the term “comprising”, features other than that or those prefaced by the term may also be present. Related terms such as “comprise” and “comprises” are to be interpreted in the same manner.

[0370] It is intended that reference to a range of numbers disclosed herein (for example, 1 to 10) also incorporates reference to all rational numbers within that range (for example, 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example, 2 to 8, 1.5 to 5.5 and 3.1 to 4.7) and, therefore, all sub-ranges of all ranges expressly disclosed herein are hereby expressly disclosed. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner.

[0371] The term ‘and / or’ means ‘and’ or ‘or’, or both.

[0372] The use of ‘(s)’ following a noun means the plural and / or singular forms of the noun.

[0373] Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and / or steps. Thus, such conditional language is not generally intended to imply that features, elements, and / or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and / or steps are included or are to be performed in any particular embodiment.

[0374] Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount.

[0375] In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally to provide a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.

[0376] In the above description, specific details are given to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, software modules, functions, circuits, etc., may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known modules, structures and techniques may not be shown in detail in order not to obscure the embodiments.

[0377] Also, it is noted that the embodiments may be described as a process that is depicted as a flowchart, a flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be rearranged. A process is terminated when its operations are completed. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc., in a computer program. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or a main function.

[0378] Aspects of the systems and methods described above may be operable or implemented on any type of specific-purpose or special computer, or any machine or computer or server or electronic device with a microprocessor, processor, microcontroller, programmable controller, or the like, or a cloud-based platform or other network of processors and / or servers, whether local or remote, or any combination of such devices.

[0379] Furthermore, embodiments may be implemented by hardware, software, firmware, middleware, microcode, or any combination thereof. When implemented in software, firmware, middleware or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine-readable medium such as a storage medium or other storage(s). A processor may perform the necessary tasks. A code segment may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and / or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.

[0380] The methods or algorithms described in connection with the examples disclosed herein may be embodied directly in hardware, in a software module executable by a processor, or in a combination of both, in the form of processing unit, programming instructions, or other directions, and may be contained in a single device or distributed across multiple devices. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD- ROM, or any other form of storage medium known in the art. A storage medium may be coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor.

[0381] One or more of the components and functions illustrated the figures may be rearranged and / or combined into a single component or embodied in several components without departing from the scope of the disclosure. Additional elements or components may also be added without departing from the scope of the disclosure. Additionally, the features described herein may be implemented in software, hardware, as a business method, and / or combination thereof.

[0382] Although this disclosure has been described in the context of certain embodiments and examples, it will be understood by those skilled in the art that the disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses and obvious modifications and equivalents thereof. In addition, while several variations of the embodiments of the disclosure have been shown and described in detail, other modifications, which are within the scope of this disclosure, will be readily apparent to those of skill in the art. It is also contemplated that various combinations or subcombinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the disclosure. For example, features described above in connection with one embodiment can be used with a different embodiment described herein, and the combination still fall within the scope of the disclosure. It should be understood that various features and aspects of the disclosed embodiments can be combined with, or substituted for, one another in order to form varying modes of the embodiments of the disclosure. Thus, it is intended that the scope of the disclosure herein should not be limited by the particular embodiments described above. Accordingly, unless otherwise stated, or unless clearly incompatible, each embodiment of this disclosure may comprise, additional to its essential features described herein, one or more features as described herein from each other embodiment of the invention disclosed herein. This disclosure may also be said broadly to consist in the parts, elements and features referred to or indicated in this disclosure, individually or collectively, and any or all combinations of any two or more said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this disclosure relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

[0383] Features, materials, characteristics, or groups described in conjunction with a particular aspect, embodiment, or example are to be understood to be applicable to any other aspect, embodiment or example described in this section or elsewhere in this specification unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The protection is not restricted to the details of any foregoing embodiments. The protection extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0384] Furthermore, certain features that are described in this disclosure in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations, one or more features from a claimed combination can, in some cases, be excised from the combination, and the combination may be claimed as a subcombination or variation of a subcombination.

[0385] Moreover, while operations may be depicted in the drawings or described in the specification in a particular order, such operations need not be performed in the particular order shown or in sequential order, or that all operations be performed, to achieve desirable results. Other operations that are not depicted or described can be incorporated in the example methods and processes. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the described operations. Further, the operations may be rearranged or reordered in other implementations. Those skilled in the art will appreciate that in some embodiments, the actual steps taken in the processes illustrated and / or disclosed may differ from those shown in the figures. Depending on the embodiment, certain of the steps described above may be removed, others may be added. Furthermore, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure. Also, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described components and systems can generally be integrated together in a single product or packaged into multiple products.

[0386] For purposes of this disclosure, certain aspects, advantages, and novel features are described herein. Not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the disclosure may be embodied or carried out in a manner that achieves one advantage or a group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

[0387] The scope of the present disclosure is not intended to be limited by the specific disclosures of embodiments in this section or elsewhere in this specification, and may be defined by claims as presented in this section or elsewhere in this specification or as presented in the future. The language of the claims is to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive.

Claims

CLAIMS1. A respiratory apparatus configured to provide a flow of gases to a user for respiratory therapy, comprising: a flow generator configured to generate the flow of gases for the user; and a humidifier comprising a heater plate configured to humidify the flow of gases; wherein the apparatus is configured to selectively operate in a therapy mode or one of a plurality of non-therapy modes, the non-therapy modes comprising at least a drying mode and a gas safety mode.

2. The respiratory apparatus according to claim 1, wherein the non-therapy modes comprise at least a drying mode and a gas safety mode; and the apparatus comprises a controller, wherein the controller is configured to: selectively either: operate the flow generator at a therapy flow rate and operate the heater plate at one or more therapy power levels to provide a humidified flow of gases along a gases flow path to the user for respiratory therapy, when the apparatus is operated in the therapy mode; or operate the flow generator according to a drying flow rate and / or the heater plate at no power or to a controller power level to dry at least a portion of the gases flow path, when the apparatus is operated in the drying mode; receive or determine oxygen concentration data indicative or representative of a concentration of oxygen in the flow of gases; compare the oxygen concentration data to one or more safety thresholds when the apparatus is operated in or transitioning to the drying mode; and switch operation of the apparatus to the gas safety mode or shut off an oxygen supply based on the comparison indicating that the concentration ofoxygen in the flow of gases to the user exceeds one or more of the safety thresholds.

3. The respiratory apparatus according to claim 2, wherein the controller is configured to switch operation of the apparatus to the gas safety mode or shut off an oxygen supply based on the comparison indicating that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds continuously for a predetermined duration.

4. The respiratory apparatus according to claim 2 or 3, wherein the apparatus includes one or more ultrasound or ultrasonic gas concentration sensors configured to generate the oxygen concentration data or information for use in deducing the oxygen concentration data.

5. The respiratory apparatus according to claim 4, wherein the one or more sensors are configured to measure a flow rate of the flow of gases and a flow rate of supplemental oxygen provided into the gases flow path.

6. The respiratory apparatus according to claim 5, wherein the one or more sensors are positioned in line with the flow of gases.

7. The respiratory apparatus according to any one of claims 2 to 6, wherein the controller power level is a low power level such that no more than a negligible portion of the flow of gases along the gases flow path to the user is humidified.

8. The respiratory apparatus according to any one of claims 2 to 7, wherein the apparatus is connectable to a heatable breathing conduit that forms part of the gases flow path for conveying the humidified flow of gases to the user.

9. The respiratory apparatus according to claim 8, wherein the heatable breathing conduit comprises a first end that is connected or connectable to a gases outlet of the respiratory apparatus and a second end that is connected or connectable to a patient interface.

10. The respiratory apparatus according to claim 9, wherein the patient interface includes one or more patient detection sensors configured to monitor the connection status of the user to the patient interface.

11. The respiratory apparatus according to claim 10, wherein the controller is configured to receive or determine connection status data from the one or more patient detection sensors, the connection status data being indicative or representative of the connection status of the user to the patient interface.

12. The respiratory apparatus according to claim 11, wherein the controller is configured to stop the drying mode or prevent the drying mode from being activated if the controller determines from the connection status data that the user is not connected to the patient interface.

13. The respiratory apparatus according to any one of claims 8 to 12, wherein the heatable breathing conduit includes one or more heater wires that are configured to heat at least a portion of the breathing conduit and the flow of gases conveyed by the breathing conduit based on the controller power applied to the one or more heater wires.

14. The respiratory apparatus according to claim 13, wherein, when the apparatus is operated in the drying mode, the controller is configured to provide full power or substantially full or high power to the one or more heater wires such that at least a substantial portion of the flow of gases within the heatable breathing conduit is dried.

15. The respiratory apparatus according to claim 13 or 14, wherein, when the apparatus is operated in the drying mode, the controller is configured to provide full power or substantially full or high power to the one or more heater wires to heat any liquid in the breathing conduit.

16. The respiratory apparatus according to any one of claims 13 to 15, wherein the heatable breathing conduit includes one or more temperature sensors for measuring a temperature of the flow of gases and the power provided to the heater wire is sufficient to increase the temperature of the heater wire to be above the temperature measured by the one or more temperature sensors.

17. The respiratory apparatus according to any one of claims 13 to 16, wherein the controller is configured to automatically operate the apparatus in the drying mode at the conclusion of the therapy mode.

18. The respiratory apparatus according to any one of claims 13 to 16, wherein the controller is configured to operate the apparatus in the drying mode based on user input relating to the manual initiation of the drying mode after the conclusion of the therapy mode.

19. The respiratory apparatus according to any one of claims 2 to 18, wherein the controller is configured to continue to operate the apparatus in the drying mode while the comparison indicates that the concentration of oxygen in the flow of gases does not exceed the one or more of the safety thresholds.

20. The respiratory apparatus according to any one of claims 2 to 18, wherein the controller is configured to continue to operate the apparatus in the drying mode for a predetermined duration.

21. The respiratory apparatus according to any one of claims 2 to 20, wherein the controller is configured to operate the flow generator according to two or more drying flow rates when the apparatus is operated in the drying mode.

22. The respiratory apparatus according to any one of claims 2 to 21, wherein the controller is configured to control the drying flow rate according to one or more predetermined profiles or functions when operating in the drying mode.

23. The respiratory apparatus according to any one of claims 2 to 22, wherein the or each drying flow rate is less than the therapy flow rate.

24. The respiratory apparatus according to any one of claims 2 to 22, wherein the or each drying flow rate is greater than the therapy flow rate.

25. The respiratory apparatus according to any one of claims 2 to 24, wherein the drying flow rate is consistently the maximum flow rate that can be produced by the apparatus.

26. The respiratory apparatus according to any one of claims 2 to 25, wherein the controller is configured to supply no power to the heater plate and maximum power to a heater wire(s) in a heatable breathing conduit.

27. The respiratory apparatus according to any one of claims 2 to 26, wherein the controller is configured to receive or determine humidifier temperature data indicative or representative of a temperature of or relating to the humidifier, compare the humidifier temperature data to one or more safety thresholds when the apparatus is operated in the drying mode, and end the drying mode based on the comparison indicating that the temperature of or relating to the humidifier is less than one or more of the safety thresholds.

28. The respiratory apparatus according to any one of claims 2 to 27, wherein the controller is configured to end the drying mode based on the comparison indicating that the temperature of or relating to the humidifier is continuously less than one or more of the safety thresholds for a predetermined duration.

29. The respiratory apparatus according to any one of claims 2 to 28, wherein the drying flow rate comprises a constant rate of between 10 to 16 L / min.

30. The respiratory apparatus according to any one of claims 2 to 29, wherein, the controller is configured to supply a set power level to a heater wire(s) in a heatable breathing conduit, and the drying flow rate is proportionally modulated in response to the temperature of the heater plate.

31. The respiratory apparatus according to any one of claims 2 to 30, wherein the controller is configured to receive or determine ambient noise data indicative or representative of noise produced by the apparatus, compare the ambient noise data to one or more noise thresholds when the apparatus is operated in the drying mode, and decrease the drying flow rate based on the comparison indicating that the noise produced by the apparatus is greater than one or more of the noise thresholds.

32. The respiratory apparatus according to claim 31, wherein the apparatus includes one or more sensors configured to generate the ambient noise data or information for use in deducing the ambient noise data.

33. The respiratory apparatus according to any one of claims 2 to 32, wherein the drying flow rate decreases over time.

34. The respiratory apparatus according to claim 33, wherein the drying flow rate decreases over time at a rate proportional to the decreasing temperature of the heater plate.

35. The respiratory apparatus according to any one of claims 2 to 34, wherein the controller is configured to stop the drying mode if any one of the following occurs: (a) the drying mode has run for a predetermined duration; (b) the power supplied to heater wire(s) within a heatable breathing conduit follows a predefined power curve; and (c) a heating rate of the heater plate is greater than a threshold value.

36. The respiratory apparatus according to any one of claims 2 to 35, wherein the controller is configured to monitor the power supplied to a heater wire(s) within a heatable breathing conduit and determine whether the power aligns with a predefined power curve as an indicator of whether the conduit contains moisture.

37. The respiratory apparatus according to any one of claims 2 to 36, wherein the controller is configured to carry out one or more moisture checks to detect the presence of moisture in a breathing conduit.

38. The respiratory apparatus according to claim 37, wherein the or at least one moisture check comprises monitoring the temperature of the heater plate and the input power needed to maintain a set temperature of the heater plate, thereby determining whether the temperature of the heater plate aligns with a power curve.

39. The respiratory apparatus according to claim 37, wherein the or at least one moisture check comprises monitoring the temperature of the heater plate while the heater plate provides a short heat pulse and / or monitoring the temperature ofany heatable breathing conduit while heater wire(s) within the conduit provide a short heat pulse.

40. The respiratory apparatus according to any one of claims 13 to 18, wherein, when the apparatus is operated in the gas safety mode, the controller is configured to provide no power or low power to the heater wire.

41. The respiratory apparatus according to any one of claims 2 to 40, wherein, when the apparatus is operated in the gas safety mode, the controller is configured to provide no power or low power to the heater plate.

42. The respiratory apparatus according to any one of claims 2 to 41, wherein the apparatus is configured to be operationally connected to at least one source of oxygen for blending with the flow of gases.

43. The respiratory apparatus according to claim 42, wherein the or at least one of the sources of oxygen is connected to the apparatus via a controllable valve, the controllable valve configured to control the flow rate of oxygen entering the apparatus from the oxygen source.

44. The respiratory apparatus according to claim 43, wherein the controller is configured to control the controllable valve to prevent oxygen from entering the apparatus from the oxygen source when operating in the gas safety mode.

45. The respiratory apparatus according to claim 44, wherein the controller is configured to automatically close the controllable valve based on the comparison indicating that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds.

46. The respiratory apparatus according to claim 44, wherein the controller is configured to prompt the user to manually close the controllable valve or otherwise switch off the supply from the or each source of oxygen when the comparison indicates that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds.

47. The respiratory apparatus according to any one of claims 2 to 46, wherein, when the apparatus is operated in the gas safety mode, the controller is configured to trigger or generate an alert, alarm, and / or notification based at least partly on determining that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds.

48. The respiratory apparatus according to claim 47, wherein the controller is configured to generate the alert, alarm, and / or notification in a form selected from any one or more of the following: audible, visual, and / or tactile.

49. The respiratory apparatus according to any one of claims 2 to 48, wherein, when the apparatus is operated in the gas safety mode, the controller is configured to operate the flow generator at a flushing flow rate to flush the gases flow path.

50. The respiratory apparatus according to claim 49, wherein the flushing flow rate is configured to flush any supplemental oxygen from the gases flow path of the apparatus.

51. The respiratory apparatus according to claim 49 or 50, wherein the flushing flow rate is at least 10 L / min.

52. The respiratory apparatus according to claim 49 or 50, wherein the flushing flow rate is at least 15 L / min.

53. The respiratory apparatus according to any one of claims 49 to 52, wherein the controller is configured to operate the flow generator at two or more flushing flow rates during the gas safety mode.

54. The respiratory apparatus according to any one of claims 49 to 53, wherein the controller is configured to operate the flow generator at the or each flushing flow rate automatically based on the comparison indicating that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds.

55. The respiratory apparatus according to any one of claims 49 to 53, wherein the controller is configured to operate the flow generator at the or each flushing flow rate based on user input relating to the manual initiation of a flushing flow.

56. The respiratory apparatus according to any one of claims 49 to 55, wherein the controller is configured to operate the flow generator at the or each flushing flow rate for a predetermined duration.

57. The respiratory apparatus according to any one of claims 49 to 55, wherein the controller is configured to operate the flow generator at the or each flushing flow rate until the concentration of oxygen in the flow of gases is less than or equal to one or more of the safety thresholds.

58. The respiratory apparatus according to any one of claims 2 to 57, wherein the plurality of non-therapy modes includes a standby mode.

59. The respiratory apparatus according to any one of claims 2 to 58, wherein the plurality of non-therapy modes includes a disinfection mode.

60. The respiratory apparatus according to any one of claim 59, wherein, when the apparatus is operated in the disinfection mode, the controller is configured to operate the flow generator at a flushing flow rate to flush the gases flow path.

61. The respiratory apparatus according to claim 60, wherein the flushing flow rate is configured to flush any supplemental oxygen from the gases flow path of the apparatus.

62. The respiratory apparatus according to claim 60 or 61, wherein the flushing flow rate is at least 10 L / min.

63. The respiratory apparatus according to claim 60 or 61 , wherein the flushing flow rate is at least 15 L / min.

64. The respiratory apparatus according to any one of claims 60 to 63, wherein the controller is configured to operate the flow generator at two or more flushing flow rates during the disinfection mode.

65. The respiratory apparatus according to any one of claims 60 to 64, wherein the controller is configured to operate the flow generator at the or each flushing flow rate automatically based on the comparison indicating that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds.

66. The respiratory apparatus according to any one of claims 60 to 64, wherein the controller is configured to operate the flow generator at the or each flushing flow rate based on user input relating to the manual initiation of a flushing flow.

67. The respiratory apparatus according to any one of claims 60 to 66, wherein the controller is configured to operate the flow generator at the or each flushing flow rate for a predetermined duration.

68. The respiratory apparatus according to any one of claims 60 to 66, wherein the controller is configured to operate the flow generator at the or each flushing flow rate until the concentration of oxygen in the flow of gases is less than or equal to one or more of the safety thresholds.

69. The respiratory apparatus according to any one of claims 60 to 68, wherein the heater plate is controlled to no power or low power when the flow generator is operated at the flushing flow rate.

70. The respiratory apparatus according to any one of claims 60 to 69, wherein the or any heater wire(s) of the or any heatable breathing conduit are controlled to no power or low power when the flow generator is operated at the flushing flow rate.

71. The respiratory apparatus according to any one of claims 2 to 70, wherein the plurality of non-therapy modes includes a cooling mode.

72. The respiratory apparatus according to claim 71, wherein the controller is configured to further selectively operate the flow generator at one or more cooling flow rates and / or the heater plate to a controlled power level to cool at least a portion of the gases flow path.

73. The respiratory apparatus according to claim 71 or 72, wherein the controller is configured to: compare the oxygen concentration data to one or more safety thresholds when the apparatus is operated in or transitioning to the cooling mode; and switch operation of the apparatus to the gas safety mode or shut off an oxygen supply based on the comparison indicating that the concentration of oxygen in the flow of gases to the user exceeds one or more of the safety thresholds.

74. The respiratory apparatus according to any one of claims 71 to 73, wherein the heater plate is controlled to no power or low power during the cooling mode.

75. The respiratory apparatus according to any one of claims 71 to 74, wherein the or any heater wire(s) of the or any heatable breathing conduit are controlled to no power or low power during the cooling mode.

76. The respiratory apparatus according to claim 1, wherein the non-therapy modes comprise at least a cooling mode and a drying mode; and the apparatus comprises a controller, wherein the controller is configured to: selectively either: operate the flow generator at a therapy flow rate and operate the heater plate at one or more therapy power levels to provide a humidified flow of gases along a gases flow path to the user for respiratory therapy, when the apparatus is operated in the therapy mode; operate the flow generator according to a cooling flow rate and / or the heater plate to a controlled power level to cool at least a portion of the gases flow path, when the apparatus is operated in the cooling mode; or operate the flow generator according to a drying flow rate and / or the heater plate at no power or to a controller power level to dry at least a portion of the gases flow path, when the apparatus is operated in the drying mode; detect the conclusion of the therapy mode and operate the apparatus in the cooling mode at the detected conclusion of the therapy mode to cool the heater plate and / or other components of the humidifier; and switch operation of the apparatus to the drying mode.

77. The respiratory apparatus according to claim 76, wherein the controller is configured to operate the apparatus in the drying mode after operating the apparatus in the cooling mode and / or at the conclusion of the cooling mode.

78. The respiratory apparatus according to claim 76 or 77, wherein the controller is configured to switch operation of the apparatus to the drying mode after a predetermined duration.

79. The respiratory apparatus according to any one of claims 76 to 78, wherein the controller is configured to receive or determine humidifier temperature data indicative or representative of a temperature of or relating to the humidifier, compare the humidifier temperature data to one or more safety thresholds when the apparatus is operated in the therapy mode, and switch operation of the apparatus to the cooling mode based on the comparison indicating that the temperature of or relating to the humidifier is greater than one or more of the safety thresholds.

80. The respiratory apparatus according to claim 79, wherein the controller is configured to switch operation of the apparatus to the cooling mode based on the comparison indicating that the temperature of or relating to the humidifier is continuously greater than one or more of the safety thresholds for a predetermined duration.

81. The respiratory apparatus according to any one of claims 76 to 80, wherein the controller is configured to receive or determine humidifier temperature data indicative or representative of a temperature of or relating to the humidifier, compare the humidifier temperature data to one or more safety thresholds when the apparatus is operated in the therapy mode or operated in or transitioning to the cooling mode, and switch operation of the apparatus to the drying modebased on the comparison indicating that the temperature of or relating to the humidifier is less than one or more of the safety thresholds.

82. The respiratory apparatus according to claim 81, wherein the controller is configured to switch operation of the apparatus to the drying mode after operating the apparatus in the cooling mode and / or at the conclusion of the cooling mode.

83. The respiratory apparatus according to claim 81 or 82, wherein the controller is configured to switch operation of the apparatus to the drying mode based on the comparison indicating that the temperature of or relating to the humidifier is continuously less than one or more of the safety thresholds for a predetermined duration.

84. The respiratory apparatus according to any one of claims 81 to 83, wherein the apparatus includes one or more sensors configured to generate the humidifier temperature data or information for use in deducing the humidifier temperature data.

85. The respiratory apparatus according to any one of claims 81 to 84, wherein the temperature of the heater plate is measured as an indication of the temperature of the humidifier.

86. The respiratory apparatus according to any one of claims 76 to 85, wherein the controller is configured to operate the apparatus in the cooling mode after operating the apparatus in the drying mode and / or at the conclusion of the drying mode.

87. The respiratory apparatus according to any one of claims 76 to 86, wherein the heater plate is controlled to no power or low power during the cooling mode.

88. The respiratory apparatus according to any one of claims 76 to 87, wherein the apparatus is connectable to a heatable breathing conduit that forms part of the gases flow path for conveying the humidified flow of gases to the user.

89. The respiratory apparatus according to claim 88, wherein the heatable breathing conduit comprises a first end that is connected or connectable to a gases outlet of the respiratory apparatus and a second end that is connected or connectable to a patient interface.

90. The respiratory apparatus according to claim 89, wherein the patient interface includes one or more patient detection sensors configured to monitor the connection status of the user to the patient interface.

91. The respiratory apparatus according to claim 90, wherein the controller is configured to receive or determine connection status data from the one or more patient detection sensors, the connection status data being indicative or representative of the connection status of the user to the patient interface.

92. The respiratory apparatus according to claim 91, wherein the controller is configured to stop the drying mode or prevent the drying mode from being activated if the controller determines from the connection status data that the user is not connected to the patient interface.

93. The respiratory apparatus according to any one of claims 89 to 92, wherein the second end of the breathing conduit includes one or more temperature sensors and the controller is configured to operate the apparatus in the cooling mode after operating the apparatus in the drying mode and / or at the conclusion of the drying mode until the measured temperature at the second end of the breathing conduit is less than ambient temperature or less than 25 degrees Celsius.

94. The respiratory apparatus according to any one of claims 89 to 93, wherein the heatable breathing conduit comprises one or more heater wires that are configured to heat at least a portion of the breathing conduit and the flow of gases conveyed by the breathing conduit based on the controller power applied to the one or more heater wires.

95. The respiratory apparatus according to claim 94, wherein the heater wire(s) of the heatable breathing conduit are controlled to no power or low power during the cooling mode.

96. The respiratory apparatus according to claim 94, wherein the power provided to the heater wire(s) is sufficient to ensure that the second end of the breathing conduit is maintained at a predetermined temperature.

97. The respiratory apparatus according to claim 96, wherein the first end of the breathing conduit is connected to a gases outlet of a chamber of the humidifier and the power provided to the heater wire is sufficient to ensure that the temperature at the second end of the breathing conduit is 1 to 5 degrees Celsius greater than the temperature at the gases outlet of the chamber.

98. The respiratory apparatus according to claim 97, wherein the gases outlet of the chamber and the second end of the breathing conduit both contain one or more temperature sensors.

99. The respiratory apparatus according to any one of claims 76 to 98, wherein the controller is configured to variably determine the cooling flow rate based on humidifier temperature data and one or more determined ambient temperatures.

100. The respiratory apparatus according to any one of claims 76 to 99, wherein the controller is configured to operate the flow generator at the cooling flow rate for a predetermined duration.

101. The respiratory apparatus according to any one of claims 76 to 100, wherein the cooling flow rate is greater than or equal to the therapy flow rate.

102. The respiratory apparatus according to any one of claims 76 to 101, wherein the cooling flow rate is based on a maximum speed of a motor of the flow generator.

103. The respiratory apparatus according to any one of claims 76 to 102, wherein the controller is configured to detect the conclusion of the therapy mode based on user input relating to the manual termination of the therapy mode or on a disconnection of a patient interface for a predetermined duration.

104. The respiratory apparatus according to any one of claims 76 to 103, wherein the controller power level is a low power level such that no more than a negligible portion of the flow of gases along the gases flow path to the user is humidified.

105. The respiratory apparatus according to any one of claims 94 to 98, wherein, when the apparatus is operated in the drying mode, the controller is configured to provide full power or substantially full or high power to the heater wire(s) such that at least a substantial portion of the flow of gases within the breathing conduit is dried.

106. The respiratory apparatus according to any one of claims 94 to 98, wherein, when the apparatus is operated in the drying mode, the controller is configured to provide full power or substantially full or high power to the heater wire(s) to heat any liquid in the breathing conduit.

107. The respiratory apparatus according to any one of claims 76 to 106, wherein the controller is configured to operate the flow generator according to two or more as when the apparatus is operated in the drying mode.

108. The respiratory apparatus according to any one of claims 76 to 107, wherein the controller is configured to control the drying flow rate according to one or more predetermined profiles or functions when operating in the drying mode.

109. The respiratory apparatus according to any one of claims 76 to 108, wherein the or each drying flow rate is less than the therapy flow rate.

110. The respiratory apparatus according to any one of claims 76 to 108, wherein the or each drying flow rate is greater than the therapy flow rate.

111. The respiratory apparatus according to any one of claims 76 to 110, wherein the drying flow rate is consistently the maximum flow rate that can be produced by the apparatus.

112. The respiratory apparatus according to any one of claims 76 to 111, wherein the controller is configured to supply no power to the heater plate and maximum power to a heater wire(s) in a heatable breathing conduit.

113. The respiratory apparatus according to any one of claims 76 to 112, wherein the controller is configured to receive or determine humidifier temperature data indicative or representative of a temperature of or relating to the humidifier, compare the humidifier temperature data to one or more safety thresholds when the apparatus is operated in the drying mode, and end the drying mode based on the comparison indicating that the temperature of or relating to the humidifier is less than one or more of the safety thresholds.

114. The respiratory apparatus according to any one of claims 76 to 113, wherein the controller is configured to end the drying mode based on the comparison indicating that the temperature of or relating to the humidifier is continuously less than one or more of the safety thresholds for a predetermined duration.

115. The respiratory apparatus according to any one of claims 76 to 114, wherein, the drying flow rate comprises a constant rate of between 10 to 16 L / min.

116. The respiratory apparatus according to any one of claims 76 to 115, wherein the controller is configured to supply a set power level to a heater wire(s) in a heatable breathing conduit, and the drying flow rate is proportionally modulated in response to the temperature of the heater plate.

117. The respiratory apparatus according to any one of claims 76 to 116, wherein the controller is configured to receive or determine ambient noise data indicative or representative of noise produced by the apparatus, compare the ambient noise data to one or more noise thresholds when the apparatus is operated in the drying mode, and decrease the drying flow rate based on the comparison indicating that the noise produced by the apparatus is greater than one or more of the noise thresholds.

118. The respiratory apparatus according to claim 117, wherein the apparatus includes one or more sensors configured to generate the ambient noise data or information for use in deducing the ambient noise data.

119. The respiratory apparatus according to any one of claims 76 to 118, wherein the drying flow rate decreases over time.

120. The respiratory apparatus according to claim 119, wherein the drying flow rate decreases over time at a rate proportional to the decreasing temperature of the heater plate.

121. The respiratory apparatus according to any one of claims 76 to 120, wherein the controller is configured to stop the drying mode if any one of the following occurs: (a) the drying mode has run for a predetermined duration; (b) the power supplied to heater wire(s) within a heatable breathing conduit follows a predefined power curve; and (c) a heating rate of the heater plate is greater than a threshold value.

122. The respiratory apparatus according to any one of claims 76 to 121, wherein the controller is configured to monitor the power supplied to a heater wire(s) within a heatable breathing conduit and determine whether the power aligns with a predefined power curve as an indicator of whether the conduit contains moisture.

123. The respiratory apparatus according to any one of claims 76 to 122, wherein the controller is configured to carry out one or more moisture checks to detect the presence of moisture in a breathing conduit.

124. The respiratory apparatus according to claim 123, wherein the or at least one moisture check comprises monitoring the temperature of the heater plate and the input power needed to maintain a set temperature of the heater plate, thereby determining whether the temperature of the heater plate aligns with a power curve.

125. The respiratory apparatus according to claim 123, wherein the or at least one moisture check comprises monitoring the temperature of the heater plate while the heater plate provides a short heat pulse and / or monitoring the temperature ofany heatable breathing conduit while heater wire(s) within the conduit provide a short heat pulse.

126. The respiratory apparatus according to any one of claims 76 to 125, wherein the controller is configured to receive or determine oxygen concentration data indicative or representative of a concentration of oxygen in the flow of gases, compare the oxygen concentration data to one or more safety thresholds when the apparatus is operated in or transitioning to the cooling mode or the drying mode, and switch operation of the apparatus from the cooling mode or the drying mode to a gas safety mode based on the comparison indicating that the concentration of oxygen in the flow of gases to the user exceeds one or more of the safety thresholds.

127. The respiratory apparatus according to claim 126, wherein the controller is configured to switch operation of the apparatus from the gas safety mode back to the cooling mode.

128. The respiratory apparatus according to claim 127, wherein the controller is configured to operate the apparatus in the following order: (a) therapy mode; (b) cooling mode; (c) gas safety mode; (d) cooling mode; and (e) drying mode.

129. The respiratory apparatus according to claim 126, wherein the controller is configured to switch operation of the apparatus from the gas safety mode back to the drying mode.

130. The respiratory apparatus according to claim 129, wherein the controller is configured to operate the apparatus in the following order: (a) therapy mode; (b) cooling mode; (c) drying mode; (d) gas safety mode; and (e) drying mode.

131. The respiratory apparatus according to any one of claims 76 to 130, wherein the plurality of non-therapy modes includes a standby mode.

132. The respiratory apparatus according to any one of claims 76 to 131, wherein the plurality of non-therapy modes includes a disinfection mode.

133. The respiratory apparatus according to any one of claim 132, wherein, when the apparatus is operated in the disinfection mode, the controller is configured to operate the flow generator at a flushing flow rate to flush the gases flow path.

134. The respiratory apparatus according to claim 133, wherein the flushing flow rate is configured to flush any supplemental oxygen from the gases flow path of the apparatus.

135. The respiratory apparatus according to claim 133 or 134, wherein the flushing flow rate is at least 10 L / min.

136. The respiratory apparatus according to claim 133 or 134, wherein the flushing flow rate is at least 15 L / min.

137. The respiratory apparatus according to any one of claims 133 to 136, wherein the controller is configured to operate the flow generator at two or more flushing flow rates during the disinfection mode.

138. The respiratory apparatus according to any one of claims 133 to 137, wherein the controller is configured to operate the flow generator at the or each flushing flow rate automatically based on the comparison indicating that the concentration of oxygen in the flow of gases exceeds one or more of the safety thresholds.

139. The respiratory apparatus according to any one of claims 133 to 137, wherein the controller is configured to operate the flow generator at the or each flushing flow rate based on user input relating to the manual initiation of a flushing flow.

140. The respiratory apparatus according to any one of claims 133 to 139, wherein the controller is configured to operate the flow generator at the or each flushing flow rate for a predetermined duration.

141. The respiratory apparatus according to any one of claims 133 to 139, wherein the controller is configured to operate the flow generator at the or each flushing flow rate until the concentration of oxygen in the flow of gases is less than or equal to one or more of the safety thresholds.

142. The respiratory apparatus according to any one of claims 133 to 141, wherein the heater plate is controlled to no power or low power when the flow generator is operated at the flushing flow rate.

143. The respiratory apparatus according to any one of claims 132 to 141, wherein the or any heater wire(s) of the or any heatable breathing conduit are controlled to no power or low power when the flow generator is operated at the flushing flow rate.

144. The respiratory apparatus according to claim 1, wherein the non-therapy modes comprise at least a cooling mode, a gas safety mode, and a drying mode; and the apparatus comprises a controller, wherein the controller is configured to: selectively either: operate the flow generator at a therapy flow rate and operate the heater plate at one or more therapy power levels to provide a humidified flow of gases along a gases flow path to the user forrespiratory therapy, when the apparatus is operated in the therapy mode; operate the flow generator according to a cooling flow rate and / or the heater plate to a controlled power level to cool at least a portion of the gases flow path, when the apparatus is operated in the cooling mode; or operate the flow generator according to a drying flow rate and / or the heater plate at no power or to a controller power level to dry at least a portion of the gases flow path, when the apparatus is operated in the drying mode; detect the conclusion of the therapy mode and operate the apparatus in the cooling mode at the detected conclusion of the therapy mode to cool the heater plate and / or other components of the humidifier; switch operation of the apparatus to the drying mode; receive or determine oxygen concentration data indicative or representative of a concentration of oxygen in the flow of gases; compare the oxygen concentration data to one or more safety thresholds when the apparatus is operated in or transitioning to the drying mode; and switch operation of the apparatus to the gas safety mode or shut off an oxygen supply based on the comparison indicating that the concentration of oxygen in the flow of gases to the user exceeds one or more of the safety thresholds.

145. The respiratory apparatus according to claim 1, wherein the non-therapy modes comprise at least a cooling mode, a gas safety mode, and a drying mode; and the apparatus comprises a controller, wherein the controller is configured to: operate a cooling mode, enter drying mode at the end of the cooling mode, and periodically during cooling mode or drying mode or during both modes detect the presence of oxygen or a patient, and activate a gas safety mode if oxygenis detected above a threshold or alarm or deactivate the apparatus or one or more components of the apparatus or one or more components connected to the apparatus if a patient is detected.

146. The respiratory apparatus according to claim 145, comprising any one or more of the features as per any one or more of claims 1 to 144.

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