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2 BACKGROUND OF THE TECHNOLOGY

2.1 Field of the Technology

The present technology relates to one or more of the screening, diagnosis, monitoring, treatment, prevention and amelioration of respiratory-related disorders. The present technology also relates to medical devices or apparatus, and their use.

2.2 Description of the Related Art

2.2.1 Human Respiratory System and its Disorders

The respiratory system of the body facilitates gas exchange. The nose and mouth form the entrance to the airways of a patient.

The airways include a series of branching tubes, which become narrower, shorter and more numerous as they penetrate deeper into the lung. The prime function of the lung is gas exchange, allowing oxygen to move from the inhaled air into the venous blood and carbon dioxide to move in the opposite direction. The trachea divides into right and left main bronchi, which further divide eventually into terminal bronchioles. The bronchi make up the conducting airways, and do not take part in gas exchange. Further divisions of the airways lead to the respiratory bronchioles, and eventually to the alveoli. The alveolated region of the lung is where the gas exchange takes place, and is referred to as the respiratory zone. See “Respiratory Physiology”, by John B. West, Lippincott Williams & Wilkins, 9th edition published 2012.

A range of respiratory disorders exist. Certain disorders may be characterised by particular events, e.g. apneas, hypopneas, and hyperpneas.

Examples of respiratory disorders include Obstructive Sleep Apnea (OSA), Cheyne-Stokes Respiration (CSR), respiratory insufficiency, Obesity Hyperventilation Syndrome (OHS), Chronic Obstructive Pulmonary Disease (COPD), Neuromuscular Disease (NMD) and Chest wall disorders.

Obstructive Sleep Apnea (OSA), a form of Sleep Disordered Breathing (SDB), is characterised by events including occlusion or obstruction of the upper air passage during sleep. It results from a combination of an abnormally small upper airway and the normal loss of muscle tone in the region of the tongue, soft palate and posterior oropharyngeal wall during sleep. The condition causes the affected patient to stop breathing for periods typically of 30 to 120 seconds in duration, sometimes 200 to 300 times per night. It often causes excessive daytime somnolence, and it may cause cardiovascular disease and brain damage. The syndrome is a common disorder, particularly in middle aged overweight males, although a person affected may have no awareness of the problem. See U.S. Pat. No. 4,944,310 (Sullivan).

Cheyne-Stokes Respiration (CSR) is another form of sleep disordered breathing. CSR is a disorder of a patient's respiratory controller in which there are rhythmic alternating periods of waxing and waning ventilation known as CSR cycles. CSR is characterised by repetitive de-oxygenation and re-oxygenation of the arterial blood. It is possible that CSR is harmful because of the repetitive hypoxia. In some patients CSR is associated with repetitive arousal from sleep, which causes severe sleep disruption, increased sympathetic activity, and increased afterload. See U.S. Pat. No. 6,532,959 (Berthon-Jones).

Respiratory failure is an umbrella term for respiratory disorders in which the lungs are unable to inspire sufficient oxygen or exhale sufficient CO2to meet the patient's needs. Respiratory failure may encompass some or all of the following disorders.

A patient with respiratory insufficiency (a form of respiratory failure) may experience abnormal shortness of breath on exercise.

Obesity Hyperventilation Syndrome (OHS) is defined as the combination of severe obesity and awake chronic hypercapnia, in the absence of other known causes for hypoventilation. Symptoms include dyspnea, morning headache and excessive daytime sleepiness.

Chronic Obstructive Pulmonary Disease (COPD) encompasses any of a group of lower airway diseases that have certain characteristics in common. These include increased resistance to air movement, extended expiratory phase of respiration, and loss of the normal elasticity of the lung. Examples of COPD are emphysema and chronic bronchitis. COPD is caused by chronic tobacco smoking (primary risk factor), occupational exposures, air pollution and genetic factors. Symptoms include: dyspnea on exertion, chronic cough and sputum production.

Neuromuscular Disease (NMD) is a broad term that encompasses many diseases and ailments that impair the functioning of the muscles either directly via intrinsic muscle pathology, or indirectly via nerve pathology. Some NMD patients are characterised by progressive muscular impairment leading to loss of ambulation, being wheelchair-bound, swallowing difficulties, respiratory muscle weakness and, eventually, death from respiratory failure. Neuromuscular disorders can be divided into rapidly progressive and slowly progressive: (i) Rapidly progressive disorders: Characterised by muscle impairment that worsens over months and results in death within a few years (e.g. Amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers); (ii) Variable or slowly progressive disorders: Characterised by muscle impairment that worsens over years and only mildly reduces life expectancy (e.g. Limb girdle, Facioscapulohumeral and Myotonic muscular dystrophy). Symptoms of respiratory failure in NMD include: increasing generalised weakness, dysphagia, dyspnea on exertion and at rest, fatigue, sleepiness, morning headache, and difficulties with concentration and mood changes.

Chest wall disorders are a group of thoracic deformities that result in inefficient coupling between the respiratory muscles and the thoracic cage. The disorders are usually characterised by a restrictive defect and share the potential of long term hypercapnic respiratory failure. Scoliosis and/or kyphoscoliosis may cause severe respiratory failure. Symptoms of respiratory failure include: dyspnea on exertion, peripheral oedema, orthopnea, repeated chest infections, morning headaches, fatigue, poor sleep quality and loss of appetite.

A range of therapies have been used to treat or ameliorate such conditions. Furthermore, otherwise healthy individuals may take advantage of such therapies to prevent respiratory disorders from arising. However, these have a number of shortcomings.

2.2.2 Therapy

Various therapies, such as Continuous Positive Airway Pressure (CPAP) therapy, Non-invasive ventilation (NIV) and Invasive ventilation (IV) have been used to treat one or more of the above respiratory disorders.

Continuous Positive Airway Pressure (CPAP) therapy has been used to treat Obstructive Sleep Apnea (OSA). The mechanism of action is that continuous positive airway pressure acts as a pneumatic splint and may prevent upper airway occlusion, such as by pushing the soft palate and tongue forward and away from the posterior oropharyngeal wall. Treatment of OSA by CPAP therapy may be voluntary, and hence patients may elect not to comply with therapy if they find devices used to provide such therapy one or more of: uncomfortable, difficult to use, expensive and aesthetically unappealing.

Non-invasive ventilation (NIV) provides ventilatory support to a patient through the upper airways to assist the patient breathing and/or maintain adequate oxygen levels in the body by doing some or all of the work of breathing. The ventilatory support is provided via a non-invasive patient interface. NIV has been used to treat CSR and respiratory failure, in forms such as OHS, COPD, NMD and Chest Wall disorders. In some forms, the comfort and effectiveness of these therapies may be improved.

Invasive ventilation (IV) provides ventilatory support to patients that are no longer able to effectively breathe themselves and may be provided using a tracheostomy tube. In some forms, the comfort and effectiveness of these therapies may be improved.

2.2.3 Treatment Systems

These therapies may be provided by a treatment system or device. Such systems and devices may also be used to screen, diagnose, or monitor a condition without treating it.

A treatment system may comprise a Respiratory Pressure Therapy Device (RPT device), an air circuit, a humidifier, a patient interface, and data management.

Another form of treatment system is a mandibular repositioning device.

2.2.3.1 Patient Interface

A patient interface may be used to interface respiratory equipment to its wearer, for example by providing a flow of air to an entrance to the airways. The flow of air may be provided via a mask to the nose and/or mouth, a tube to the mouth or a tracheostomy tube to the trachea of a patient. Depending upon the therapy to be applied, the patient interface may form a seal, e.g., with a region of the patient's face, to facilitate the delivery of gas at a pressure at sufficient variance with ambient pressure to effect therapy, e.g., at a positive pressure of about 10 cmH2O relative to ambient pressure. For other forms of therapy, such as the delivery of oxygen, the patient interface may not include a seal sufficient to facilitate delivery to the airways of a supply of gas at a positive pressure of about 10 cmH2O.

Certain other mask systems may be functionally unsuitable for the present field. For example, purely ornamental masks may be unable to maintain a suitable pressure. Mask systems used for underwater swimming or diving may be configured to guard against ingress of water from an external higher pressure, but not to maintain air internally at a higher pressure than ambient.

Certain masks may be clinically unfavourable for the present technology e.g. if they block airflow via the nose and only allow it via the mouth.

Certain masks may be uncomfortable or impractical for the present technology if they require a patient to insert a portion of a mask structure in their mouth to create and maintain a seal via their lips.

Certain masks may be impractical for use while sleeping, e.g. for sleeping while lying on one's side in bed with a head on a pillow.

The design of a patient interface presents a number of challenges. The face has a complex three-dimensional shape. The size and shape of noses and heads varies considerably between individuals. Since the head includes bone, cartilage and soft tissue, different regions of the face respond differently to mechanical forces. The jaw or mandible may move relative to other bones of the skull. The whole head may move during the course of a period of respiratory therapy.

As a consequence of these challenges, some masks suffer from being one or more of obtrusive, aesthetically undesirable, costly, poorly fitting, difficult to use, and uncomfortable especially when worn for long periods of time or when a patient is unfamiliar with a system. Wrongly sized masks can give rise to reduced compliance, reduced comfort and poorer patient outcomes. Masks designed solely for aviators, masks designed as part of personal protection equipment (e.g. filter masks), SCUBA masks, or for the administration of anaesthetics may be tolerable for their original application, but nevertheless such masks may be undesirably uncomfortable to be worn for extended periods of time, e.g., several hours. This discomfort may lead to a reduction in patient compliance with therapy. This is even more so if the mask is to be worn during sleep.

CPAP therapy is highly effective to treat certain respiratory disorders, provided patients comply with therapy. If a mask is uncomfortable, or difficult to use a patient may not comply with therapy. Since it is often recommended that a patient regularly wash their mask, if a mask is difficult to clean (e.g., difficult to assemble or disassemble), patients may not clean their mask and this may impact on patient compliance.

While a mask for other applications (e.g. aviators) may not be suitable for use in treating sleep disordered breathing, a mask designed for use in treating sleep disordered breathing may be suitable for other applications.

For these reasons, patient interfaces for delivery of CPAP during sleep form a distinct field.

2.2.3.2 Respiratory Pressure Therapy (RPT) Device

A respiratory pressure therapy (RPT) device may be used individually or as part of a system to deliver one or more of a number of therapies described above, such as by operating the device to generate a flow of air for delivery to an interface to the airways. The flow of air may be pressurised. Examples of RPT devices include a CPAP device and a ventilator.

Air pressure generators are known in a range of applications, e.g. industrial-scale ventilation systems. However, air pressure generators for medical applications have particular requirements not fulfilled by more generalised air pressure generators, such as the reliability, size and weight requirements of medical devices. In addition, even devices designed for medical treatment may suffer from shortcomings, pertaining to one or more of: comfort, noise, ease of use, efficacy, size, weight, manufacturability, cost, and reliability.

An example of the special requirements of certain RPT devices is acoustic noise.

Table of noise output levels of prior RPT devices (one specimen only, measured using test method specified in ISO 3744 in CPAP mode at 10 cmH2O).

A-weightedsoundpressureYearRPT Device namelevel dB(A)(approx.)C-Series Tango ™31.92007C-Series Tango ™ with Humidifier33.12007S8 Escape ™ II30.52005S8 Escape ™ II with H4i ™ Humidifier31.12005S9 AutoSet ™26.52010S9 AutoSet ™ with H5i Humidifier28.62010

One known RPT device used for treating sleep disordered breathing is the S9 Sleep Therapy System, manufactured by ResMed Limited. Another example of an RPT device is a ventilator. Ventilators such as the ResMed Stellar™ Series of Adult and Paediatric Ventilators may provide support for invasive and non-invasive non-dependent ventilation for a range of patients for treating a number of conditions such as but not limited to NMD, OHS and COPD.

The ResMed Elisée™ 150 ventilator and ResMed VS III™ ventilator may provide support for invasive and non-invasive dependent ventilation suitable for adult or paediatric patients for treating a number of conditions. These ventilators provide volumetric and barometric ventilation modes with a single or double limb circuit. RPT devices typically comprise a pressure generator, such as a motor-driven blower or a compressed gas reservoir, and are configured to supply a flow of air to the airway of a patient. In some cases, the flow of air may be supplied to the airway of the patient at positive pressure. The outlet of the RPT device is connected via an air circuit to a patient interface such as those described above.

The designer of a device may be presented with an infinite number of choices to make. Design criteria often conflict, meaning that certain design choices are far from routine or inevitable. Furthermore, the comfort and efficacy of certain aspects may be highly sensitive to small, subtle changes in one or more parameters.

2.2.3.3 Humidifier

Delivery of a flow of air without humidification may cause drying of airways. The use of a humidifier with an RPT device and the patient interface produces humidified gas that minimizes drying of the nasal mucosa and increases patient airway comfort. In addition in cooler climates, warm air applied generally to the face area in and about the patient interface is more comfortable than cold air.

A range of artificial humidification devices and systems are known, however they may not fulfil the specialised requirements of a medical humidifier.

Medical humidifiers are used to increase humidity and/or temperature of the flow of air in relation to ambient air when required, typically where the patient may be asleep or resting (e.g. at a hospital). A medical humidifier for bedside placement may be small. A medical humidifier may be configured to only humidify and/or heat the flow of air delivered to the patient without humidifying and/or heating the patient's surroundings. Room-based systems (e.g. a sauna, an air conditioner, or an evaporative cooler), for example, may also humidify air that is breathed in by the patient, however those systems would also humidify and/or heat the entire room, which may cause discomfort to the occupants. Furthermore medical humidifiers may have more stringent safety constraints than industrial humidifiers.

While a number of medical humidifiers are known, they can suffer from one or more shortcomings. Some medical humidifiers may provide inadequate humidification, some are difficult or inconvenient to use by patients.

2.2.3.4 Data Management

There may be clinical reasons to obtain data to determine whether the patient prescribed with respiratory therapy has been “compliant”, e.g. that the patient has used their RPT device according to one or more “compliance rules”. One example of a compliance rule for CPAP therapy is that a patient, in order to be deemed compliant, is required to use the RPT device for at least four hours a night for at least 21 of 30 consecutive days. In order to determine a patient's compliance, a provider of the RPT device, such as a health care provider, may manually obtain data describing the patient's therapy using the RPT device, calculate the usage over a predetermined time period, and compare with the compliance rule. Once the health care provider has determined that the patient has used their RPT device according to the compliance rule, the health care provider may notify a third party that the patient is compliant.

There may be other aspects of a patient's therapy that would benefit from communication of therapy data to a third party or external system.

Existing processes to communicate and manage such data can be one or more of costly, time-consuming, and error-prone.

3 BRIEF SUMMARY OF THE TECHNOLOGY

The present technology is directed towards providing medical devices used in the screening, diagnosis, monitoring, amelioration, treatment, or prevention of respiratory disorders having one or more of improved comfort, cost, efficacy, ease of use and manufacturability.

A first aspect of the present technology relates to apparatus used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respiratory disorder.

Another aspect of the present technology relates to methods used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respiratory disorder.

An aspect of certain forms of the present technology is to provide methods and/or apparatus that improve the compliance of patients with respiratory therapy.

An aspect of one form of the present technology is a method of manufacturing apparatus.

An aspect of certain forms of the present technology is a medical device that is easy to use, e.g. by a person who does not have medical training, by a person who has limited dexterity, vision or by a person with limited experience in using this type of medical device.

An aspect of one form of the present technology is a portable RPT device that may be carried by a person, e.g., around the home of the person.

An aspect of one form of the present technology is a patient interface that may be washed in a home of a patient, e.g., in soapy water, without requiring specialised cleaning equipment. An aspect of one form of the present technology is a humidifier tank that may be washed in a home of a patient, e.g., in soapy water, without requiring specialised cleaning equipment.

An aspect of one form of the present technology relates to respiratory treatment apparatus including a source of a flow of air at positive pressure, a chassis or housing constructed and arranged to be fixed in location in use relative to the source, an inlet pneumatic connection structured for connecting to the source to receive sealably the flow of air at positive pressure from the source in use, a container to hold a body of water in use, the container being configured to direct the flow of air so that water vapour may transfer from the body of water to the flow of air in use to increase the absolute humidity of the flow of air, the container including a wall constructed at least in part from a material having a relatively high thermal conductivity, a heating element, a temperature sensor, a controller to control the heating element, and an outlet pneumatic connection structure to receive the flow of air with increased absolute humidity. The chassis or housing is configured to hold the container in location close relative to the heating element so that heat energy may transfer from the heating element to the body of water to increase the absolute humidity of the flow of air. The controller is constructed and arranged to cause the energising of the heating element to heat the water without boiling the water. The respiratory treatment apparatus includes a sealing arrangement so that in use the flow of air with increased absolute humidity received at the outlet pneumatic connection structure has a positive pressure with respect to ambient.

Another aspect of the present technology relates to a CPAP system including a humidifier, a patient interface, and an air delivery tube to deliver humidified air to the patient interface. In an example, the humidifier is integrated with an RPT device structured to produce a flow of air at positive pressure.

Another aspect of the present technology relates to a humidifier including a water reservoir including a cavity structured to hold a volume of water, and a water reservoir dock structured and arranged to receive the water reservoir in an operative position.

Another aspect of the present technology relates to an apparatus for humidifying a flow of breathable gas. The apparatus includes a water reservoir and a water reservoir dock forming a cavity structured and arranged to receive the water reservoir in an operative position. The water reservoir includes a reservoir base including a cavity structured to hold a volume of water. The reservoir base includes a main body and a thermally conductive portion provided to the main body. The thermally conductive portion comprises a combined layered arrangement including a metal plate and a thin film. The thin film comprises a non-metallic material and includes a wall thickness of less than about 1 mm. The thin film is adapted to form at least a bottom interior surface of the water reservoir exposed to the volume of water, and the metal plate is adapted to form a bottom exterior surface of the water reservoir. The water reservoir dock includes a heater plate adapted to thermally contact the metal plate of the water reservoir in the operative position to allow thermal transfer of heat from the heater plate to the volume of water.

Another aspect of the present technology relates to an apparatus for humidifying a flow of breathable gas. The apparatus includes a water reservoir including a cavity structured to hold a volume of water, a water reservoir dock structured and arranged to receive the water reservoir in an operative position, and a guide arrangement structured and arranged to guide the water reservoir into and out of the operative position. The water reservoir includes a conductive portion, and the water reservoir dock includes a heating assembly adapted to thermally engage the conductive portion of the water reservoir in the operative position to allow thermal transfer of heat from the heating assembly to the volume of water. The guide arrangement includes a path extending both in an anterior-posterior direction and in an inferior-superior direction.

Another aspect of the present technology relates to an apparatus for humidifying a flow of breathable gas. The apparatus includes a water reservoir including a cavity structured to hold a volume of water, a water reservoir dock structured and arranged to receive the water reservoir in an operative position, and an air delivery tube configured to pass the flow of breathable gas that has been humidified in the water reservoir to a patient interface. The air delivery tube is structured and arranged to form a direct pneumatic seal with the water reservoir.

Another aspect of the present technology relates to a water reservoir including an inlet tube providing an inlet for receiving a flow of breathable gas and an outlet tube providing an outlet for delivering a humidified flow of breathable gas, wherein the inlet tube includes an inlet seal and the outlet tube includes an outlet seal.

Another aspect of the present technology relates to a water reservoir for an apparatus for humidifying a flow of breathable gas. The water reservoir includes an inlet tube arranged to provide an inlet for receiving a flow of breathable gas into the water reservoir and an outlet tube arranged to provide an outlet for delivering a flow of humidified breathable gas from the water reservoir. At least one of the inlet tube and the outlet tube changes a parameter at least at one point along its length. For example, at least one of the inlet tube and the outlet tube may change direction and/or cross-sectional area at least at one point along its length. In a more specific example, the inlet tube, the outlet tube, or both may curve along its/their length and/or change its cross-section along its length. The change may be abrupt (stepwise) or gradual.

Another aspect of the present technology relates to a water reservoir including a conductive portion adapted to thermally engage with a heating assembly, wherein the conductive portion includes a first portion that extends in a first plane and a second portion that extends in a second plane that is offset in a superior direction from the first plane.

Another aspect of the present technology relates to an apparatus for humidifying a flow of breathable gas. The apparatus includes a water reservoir, a water reservoir dock structured and arranged to receive the water reservoir, and an air delivery tube, wherein insertion/removal of the water reservoir to/from the water reservoir dock is independent from engagement/disengagement of the air delivery tube to/from the water reservoir dock.

Another aspect of the present technology relates to a heating assembly for a water reservoir dock including a heater plate, a heating element, and a thermal pad arranged between the heater plate and the heating element, e.g., to enhance thermal conductivity from the heating element to the heater plate.

Another aspect of the present technology relates to an apparatus for humidifying a flow of breathable gas. The apparatus includes a water reservoir including a cavity structured to hold a volume of water, the water reservoir including a conductive portion, and a water reservoir dock structured and arranged to receive the water reservoir in an operative position, the water reservoir dock including a heating assembly adapted to thermally engage the conductive portion of the water reservoir in the operative position to allow thermal transfer of heat from the heating assembly to the volume of water. The heating assembly includes a heater plate to thermally contact the conductive portion of the water reservoir, a heating element, and a thermal pad arranged between the heater plate and the heating element. The thermal pad comprises a pliable material structured and arranged to engage both the heater plate and the heating element to remove air gaps and spaces between the heater plate and the heating element to enhance thermal conductivity.

Another aspect of the present technology relates to a water reservoir including a conductive portion adapted to thermally engage with a heating assembly, wherein the conductive portion includes one of a metal plate, a thin, non-metallic film, or a combined layered arrangement of a metal plate and a thin, non-metallic film. In an example, the conductive portion may include circular or non-circular shapes.

Another aspect of the present technology relates to including one or more circuit components in an air delivery tube for identifying a type of air delivery tube based on characteristics of the circuit components.

Another aspect of the present technology relates to an apparatus for humidifying a flow of breathable gas. The apparatus includes a water reservoir including a cavity structured to hold a volume of water, a water reservoir dock structured and arranged to receive the water reservoir in an operative position, and an air delivery tube configured to pass the flow of breathable gas that has been humidified in the water reservoir to a patient interface. The air delivery tube includes a dock connector including a contact assembly. The contact assembly includes electrical contacts adapted to, in an operative configuration of the apparatus, engage respective electrical contacts provided to the water reservoir dock. The contact assembly includes an electrical characteristic used as an identifier of one or more parameters of the air delivery tube or the patient interface.

Another aspect of the present technology relates to processing circuitry configured to identify a type of air delivery tube coupled to an apparatus for humidifying a flow of breathable gas based on measured characteristics of a passive circuit component in the air delivery tube.

Another aspect of the present technology relates to processing circuitry configured to identify a type of air delivery tube coupled to an apparatus for humidifying a flow of breathable gas based on measuring characteristics of circuitry in the air delivery tube. The characteristics of the circuitry include a resistance value of one or more heating elements in the air delivery tube and/or a resistance value of one or more sensors in the air delivery tube.

Another aspect of the present technology relates to processing circuitry configured to identify a type of air delivery tube coupled to an apparatus for humidifying a flow of breathable gas based on resistance value of a first resistor and a resistance value of a second resistor provided in the air delivery tube. The first resistor being coupled to a first pair of contacts in the air delivery tube and the second resistor being coupled to a second pair of contacts in the air delivery tube.

Another aspect of the present technology relates to including one or more filters coupled to a sensor circuit at least partially disposed in an air delivery tube for sensing temperature changes in the air delivery tube.

Another aspect of the present technology relates to including low pass filters coupled to a sensor circuit at least partially disposed in an air delivery tube for sensing temperature changes in the air delivery tube. The filters may be configured to filter pulse frequencies of the PWM signal applied to one or more heating elements in the air delivery tube.

Another aspect of the present technology relates to including one or more low pass filters coupled to a sensor circuit at least partially disposed in an air delivery tube for sensing temperature changes in the air delivery tube, wherein a sensing signal is applied periodically to the sensor circuit.

Another aspect of the present technology relates to including a first low pass filter coupled to one end of a sensor included in an air delivery tube and a second low pass filter coupled to a second end of the sensor, wherein a sensing signal is applied at predetermined intervals to the sensor for sensing temperature changes in the air delivery tube.

Another aspect of the present technology relates to including a first low pass filter coupled to a first output of a divider network for detecting operating parameters of a sensor disposed in an air delivery tube and a second low pass filter coupled to a second output of the divider network.

Another aspect of the present technology relates to an apparatus for providing a supply of humidified pressurized breathable gas to a patient interface. The apparatus includes a flow generator configured to pressurize a supply of breathable gas, a humidifier configured to provide water vapour to humidify the supply of pressurized breathable gas, a heated tube configured to be connectable to the humidifier to heat and deliver the humidified supply of breathable gas to the patient interface, a sensor configured to measure a property of the humidified supply of breathable gas in the heated tube, a controller configured to control power provided to the heated tube and control operation of the flow generator, and a set of low pass filters coupled between the sensor and the controller and/or a set of low pass filters coupled between the sensor and ground.

Another aspect of the present technology relates to an apparatus for humidifying a flow of breathable gas including a water reservoir including a cavity structured to hold a volume of water, a water reservoir dock structured and arranged to receive the water reservoir in an operative position, an air delivery tube configured to pass the flow of breathable gas that has been humidified in the water reservoir to a patient interface, and an intermediate component removably and non-rotatably coupled to the water reservoir dock. The intermediate component is configured to pneumatically connect the water reservoir to the air delivery tube. The intermediate component comprises a one-piece construction of a relatively rigid material including an inlet end adapted to interface with the water reservoir and an outlet end adapted to interface with the air delivery tube. The air delivery tube includes a dock connector structured and arranged to form a bayonet-style connection with the water reservoir dock which mechanically and electrically connects the air delivery tube with the water reservoir dock.

Another aspect of the present technology relates to a water reservoir for humidifying a flow of breathable gas including a reservoir base, a reservoir lid, and a hinge joint to hingedly couple the reservoir lid to the reservoir base for hinged movement between an open position and a closed position. The hinge joint includes a pair of hinge pins each configured to engage with a respective one of a pair of slots to provide said hinged movement. Each of the pair of hinge pins comprises a cross-section that represents a major segment of a circle.

Another aspect of the present technology relates to an apparatus for humidifying a flow of breathable gas. The apparatus includes a water reservoir including a cavity structured to hold a volume of water, a water reservoir dock structured and arranged to receive the water reservoir in an operative position, and a guide arrangement structured and arranged to guide the water reservoir into the operative position with the water reservoir dock. The water reservoir includes a heat conductive portion. The water reservoir dock includes a heating assembly adapted to thermally engage the heat conductive portion of the water reservoir in the operative position to allow thermal transfer of heat from the heating assembly to the volume of water. The guide arrangement includes a guiding rail on each side of the water reservoir and a guide slot on each side of the water reservoir dock, each guiding rail configured to engage with a respective guide slot. The guide arrangement further includes one or more biasing edges or tabs provided to a leading edge of the water reservoir configured to engage underneath a respective abutment edge provided to the water reservoir dock when the water reservoir reaches the operative position. The engagement both biases the front of the water reservoir downwardly and locks/prevents its movement in an upward direction.

Another aspect of the present technology relates to an apparatus for humidifying a flow of breathable gas. The apparatus includes a water reservoir including a cavity structured to hold a volume of water and a water reservoir dock structured and arranged to receive the water reservoir in an operative position. The water reservoir includes a heat conductive portion, and the water reservoir dock includes a heating assembly adapted to thermally engage the heat conductive portion of the water reservoir in the operative position to allow thermal transfer of heat from the heating assembly to the volume of water. The heating assembly comprises a heater plate including a base surface to thermally contact the heat conductive portion of the water reservoir and a resilient sealing and/or supporting member to resiliently suspend the heater plate within the water reservoir dock. The resilient sealing and/or supporting member comprises one or more hollow tubes, each of one or more hollow tubes including an axis that is generally perpendicular to the base surface of the heater plate.

Another aspect of the present technology relates to an apparatus for humidifying a flow of breathable gas. The apparatus includes a water reservoir including a cavity structured to hold a volume of water, a water reservoir dock structured and arranged to receive the water reservoir in an operative position, an air delivery tube configured to pass the flow of breathable gas that has been humidified in the water reservoir to a patient interface, and an intermediate component arranged for removably and non-rotatably coupling to the water reservoir dock and the air delivery tube. The intermediate component is configured to, in an operational configuration, pneumatically connect the air delivery tube to the water reservoir.

Another aspect of the present technology relates to a water reservoir for humidifying a flow of breathable gas including a reservoir base including a cavity structured to hold a volume of water. The reservoir base includes a main body and a thermally conductive portion provided to the main body. The thermally conductive portion may comprise a thin film. The thin film comprises a non-metallic material and includes a wall thickness of less than about 1 mm. The main body comprises a plastic material, and the thin film comprises a non-final form that forms an insert molded connection with the main body. The thin film is formed in its final form (e.g. by stamping, vacuum forming or thermal vacuum forming) after it has been insert molded in the main body.

The methods, systems, devices and apparatus described may be implemented so as to improve the functionality of a processor, such as a processor of a specific purpose computer, respiratory monitor and/or a respiratory therapy apparatus. Moreover, the described methods, systems, devices and apparatus can provide improvements in the technological field of automated management, monitoring and/or treatment of respiratory conditions, including, for example, sleep disordered breathing.

Of course, portions of the aspects may form sub-aspects of the present technology. Also, various ones of the sub-aspects and/or aspects may be combined in various manners and also constitute additional aspects or sub-aspects of the present technology.

Other features of the technology will be apparent from consideration of the information contained in the following detailed description, abstract, drawings and claims.

