Patient interface

Abstract

The patient interface is configured to deliver a flow of pressurized breathing gas to the airways of a patient. The patient interface includes a brace base configured to support the nose of a patient in use. Two protrusions extend from the brace base and are configured to be inserted into the nostrils of a patient in use. Each protrusion has an opening formed therein configured to allow air to continuously flow therethrough. Further, an inflatable base forms a plenum chamber with the brace base. The brace base is configured such that motion of the brace base is decoupled from the inflatable base.

Description

[0001] 1 CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Australian Application No. 2019903362 filed 10 September 2019, the entire contents of which are incorporated by reference. BACKGROUND 2.1 TECHNICAL FIELD

[0004] The present technology relates to one or more of the detection, diagnosis, treatment, prevention and amelioration of respiratory-related disorders. The present technology also relates to medical devices or apparatus, and their use.

[0005] 2.2 DESCRIPTION OF RELATED ART

[0006] 2.2.1 The Human Respiratory System and Its Disorders

[0007] The respiratory system of the body facilitates gas exchange. The nose and mouth form the entrance to the airways of the patient.

[0008] The airways include a sequence of branching tubes when the branching airways penetrate deeper into the lung they become narrower, shorter and more numerous. The main function of the lung is gas exchange, allowing oxygen to enter the venous blood from inhaled air and carbon dioxide to leave the blood to be exhaled in the opposite direction. The trachea divides into the left and right bronchus, which ultimately subdivide into end- bronchioles. The bronchi constitute the conducting airways and do not participate in gas exchange. Further branching of the airways leads to the respiratory bronchioles and ultimately the pulmonary alveoli. The pulmonary alveoli region of the lung is where gas exchange occurs and is known as the respiratory zone. See West, John B. Respiratory Physiology, 9thEd. Lippincott Williams & Wilkins, 2012.

[0009] There is a range of respiratory disorders. Certain disorders can be characterised by particular events, such as apnoeas, hypopnoeas, and hyperpnoeas.

[0010] Examples of respiratory disorders include obstructive sleep apnoea (OSA), Cheyne-Stokes Respiration (CSR), respiratory insufficiency, Obesity Hypoventilation Syndrome (OHS), Chronic Obstructive Pulmonary Disease (COPD), Neuromuscular Disease (NMD), and Chest Wall Disorders.

[0011] Obstructive Sleep Apnea (OSA) is a form of Sleep Disordered Breathing (SDB) which involves partial or complete obstruction of the upper airway. It is characterized by events including occlusion or obstruction of the upper airway during sleep. It results from a combination of an abnormally small upper airway and muscular tone that is normally reduced during sleep. The condition causes the affected patient to stop breathing for periods of time, typically between 30 seconds and 120 seconds, sometimes 200 to 300 times per night. This often results in excessive daytime sleepiness, and can cause cardiovascular disease and brain damage. The condition is a common disorder, particularly in middle aged overweight males, although a person affected can have no awareness of the problem. See US Patent No. 4,944,310 (Sullivan).

[0012] Cheyne-Stokes Respiratory (CSR) is another form of Sleep Disordered Breathing. CSR is a disorder of the patient's respiratory controller where the normal inspiration / expiration cycles of respiratory control are periodically reversed. This creates a cycling pattern of hyperpnea followed by hypopnea, or apnea. CSR is characterised by a periodicity typically between 40 and 90 seconds, though this can vary from breath to breath. If the periodicity is exactly 40 seconds or exactly 90 seconds, the condition is known as classic Cheyne-Stokes Respiration. CSR is thought to be caused by a weakness in the mechanisms which work to maintain constant oxygen and carbon dioxide levels in the blood and tissues. See US Patent No. 6,532,959 (Berthon-Jones).

[0013] Respiratory failure is a term used to describe diseases of the respiratory system where the lungs are not able to take in sufficient oxygen or expel sufficient CO2 to meet the needs of the patient. Respiratory failure can encompass some or all of the following disorders.

[0014] A patient with respiratory insufficiency, a form of respiratory failure, can experience abnormally short breath.

[0015] Obesity hypoventilation syndrome (OHS) is defined as the combination of severe obesity and chronic hypercapnia in the presence of a normal awake PaC02, in the absence of other known causes of hypoventilation. Symptoms include breathlessness, morning headaches, and excessive daytime sleepiness.

[0016] 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, an extension of the exhalation phase, and loss of the normal elasticity of the lung. Examples of COPD are emphysema and chronic bronchitis. COPD is caused by chronic tobacco smoking (the primary risk factor), occupational exposures, air pollution, and genetic factors. Symptoms include labored breathing, cough, and sputum production.

[0017] Neuromuscular Disease (NMD) is a broad term that encompasses many diseases and ailments that impair muscle function either directly by intrinsic muscle pathology or indirectly by nerve pathology. Some NMD patients are characterised by progressive muscular impairment leading to loss of ambulation, being wheelchair-bound, dysphagia, 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 leads to 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 shortens life expectancy (e.g. Limb girdle, Facioscapulohumeral, and Myotonic muscular dystrophy). Symptoms of respiratory failure in NMD include: increasing generalised weakness, dysphagia, breathlessness during exercise and at rest, fatigue, sleepiness, morning headache, and difficulty concentrating and mood changes.

[0018] The chest wall is a group of thoracic deformities that result in inefficient coupling of the respiratory muscles to the thoracic cage. These disorders are often characterised by a restrictive defect and share the potential for long term hypercapnic respiratory failure. Scoliosis and / or kyphoscoliosis can cause severe respiratory failure. Symptoms of respiratory failure include: breathlessness, peripheral oedema, orthopnoea, repeated chest infections, morning headaches, fatigue, poor sleep quality and loss of appetite.

[0019] A range of therapies have been used to treat or ameliorate such conditions. Furthermore, otherwise healthy individuals can utilise such therapies to prevent the development of respiratory disorders. However, these therapies have a number of drawbacks.

[0020] 2.2.2 Treatment

[0021] 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.

[0022] Continuous positive airway pressure (CPAP) therapy has been used to treat Obstructive Sleep Apnoea (OSA). The mechanism of action is that continuous positive airway pressure acts as a pneumatic splint and can 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 can be voluntary and as such, patients can elect not to comply with treatment if they find the apparatus used to provide such therapy to be any one or more of: uncomfortable, difficult to use, expensive, and aesthetically unappealing.

[0023] Non-invasive ventilation (NIV) provides ventilatory support to a patient through the upper airways to assist the patient's breathing and / or to maintain an appropriate oxygen level 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, which takes forms such as OHS, COPD, NMD, and Chest Wall Disorder. In some forms, the comfort and effectiveness of these therapies can be improved.

[0024] Invasive ventilation (IV) provides ventilatory support to a patient who is unable to breathe effectively on their own, and can be provided using a tracheostomy tube. In some forms, the comfort and effectiveness of these therapies can be improved.

[0025] 2.2.3 Therapy Systems

[0026] These therapies can be provided by a therapy system or device. Such systems and devices can also be used to diagnose a disorder without treating the disorder.

[0027] A therapy system can include a respiratory pressure therapy device (RPT device), an air circuit, a humidifier, a patient interface, and data management.

[0028] Another form of therapy system is a mandibular repositioning device.

[0029] 2.2.3.1 Patient Interface

[0030] A patient interface can be used to interface a respiratory device to its wearer, for example, by providing a flow of air to the entrance of the airways. The flow of air can be provided via a mask to the nose and / or mouth of a patient, via a tube to the mouth, or via a tracheal tube to the trachea of a patient. The patient interface can form a seal, e.g., with areas of the patient's face, depending on the treatment to be applied, to facilitate the delivery of gas at a pressure sufficient to effect treatment, e.g., positive pressure of about 10 cmH20 relative to ambient pressure. For other forms of therapy, e.g., oxygen

[0031] Certain other mask systems can not be functionally suitable for use in the art. For example, purely decorative masks can not be able to maintain an appropriate pressure. Mask systems for use in underwater swimming or diving can be configured to prevent water from the higher pressure outside from entering, but do not maintain the air inside at a higher pressure than ambient.

[0032] Certain masks can be clinically disadvantageous for the present technology, for example, where they obstruct airflow through the nose and only allow it through the mouth.

[0033] If some masks require the patient to insert a portion of the mask structure into their mouth to create and maintain a seal through their lips, this can be uncomfortable or impractical for the present technology.

[0034] Some masks can not be achievable for use while sleeping, for example while sleeping on one's side in bed with one's head on a pillow.

[0035] The design of patient interfaces presents a number of challenges. The face has a complex three-dimensional shape. The size and shape of the nose and head varies greatly between different individuals. As the head includes bone, cartilage, and soft tissue, different regions of the face react differently to mechanical forces. The mandible, or lower jaw, can move relative to other bones of the skull. The entire head can move over the course of a respiratory therapy session.

[0036] Due to these challenges, some masks suffer from one or more of the following problems: obtrusive, unaesthetic, expensive, unproportioned, difficult to use, and uncomfortable, particularly when worn for a long period of time or when the patient is not familiar with the system. A mask that is wrongly sized can cause reduced compliance, reduced comfort, and adverse patient outcomes. A mask designed only for pilots, designed to be part of a personal protection device (such as a filtering mask), a SCUBA mask, or a mask designed for the administration of anaesthetics can be acceptable for its original purpose, but not as comfortable for long periods of wear, such as several hours. This discomfort can lead to reduced patient compliance with therapy. This is even more true if the mask is worn during sleep.

[0037] CPAP therapy is very effective at treating certain respiratory disorders, assuming the patient complies with the therapy. If the mask is uncomfortable or difficult to use, the patient can not comply with the therapy. As patients are typically advised to clean their masks on a regular basis, if the mask is difficult to clean (for example difficult to assemble or disassemble), the patient can not clean their mask, which can affect patient compliance.

[0038] While masks for other applications (such as pilots) can not be suitable for treating sleep disordered breathing, masks designed for treating sleep disordered breathing can be suitable for other applications.

[0039] For these reasons, patient interfaces for the delivery of CPAP during sleep form a distinct field.

[0040] 2.2.3.1.1 Seal-forming structure

[0041] A patient interface can include a seal-forming structure. As it is in direct contact with the patient's face, the shape and configuration of the seal-forming structure can directly affect the effectiveness and comfort of the patient interface.

[0042] A patient interface can be characterized in part by the design intent of the seal-forming structure to interface with the face in use. In one form of patient interface, the seal-forming structure can comprise a first sub-portion to form a seal around the left nare and a second sub-portion to form a seal around the right nare. In one form of patient interface, the seal-forming structure can comprise a single element that surrounds both nare in use. Such a single element can be designed to cover, for example, the upper lip region and the bridge of the nose region of the face. In one form of patient interface, the seal-forming structure can comprise an element that surrounds the mouth region in use, for example, by forming a seal over the lower lip region of the face. In one form of patient interface, the seal-forming structure can comprise a single element that surrounds both nare and the mouth region in use. These different types of patient interface can be variously named by their manufacturers, including nasal masks, full-face masks, nasal pillows, nasal puffs, and mouth-nose masks.

[0043] A seal-forming structure that can be effective in one region of a patient's face can not be suitable in another region, for example, because of the different shape, structure, variability, and sensitive areas of a patient's face. For example, a seal on a swimming goggle that covers a patient's forehead can not be suitable for use on a patient's nose.

[0044] Certain seal-forming structures can be designed for mass production, such that one design is suitable, comfortable, and effective for a wide range of different face shapes and sizes. To the extent there is a mismatch between the shape of a patient's face and the seal-forming structure of a mass-produced patient interface, one or both must accommodate to form a seal.

[0045] One type of seal-forming structure extends around the periphery of a patient interface and is intended to seal against a patient's face when a force is applied to the patient interface while the seal-forming portion is in confronting engagement with the patient's face. The seal-forming structure can comprise an air or fluid-filled cushion, or a molded or shaped surface of an elastomeric (e.g., rubber) sealing element. With this type of seal-forming structure, if the fit is not adequate, there will be a gap between the seal-forming structure and the face, and additional force will be required to force the patient interface against the face to achieve a seal.

[0046] Another type of seal-forming structure incorporates a sheet-like seal of thin material around the periphery of the mask to provide a self-sealing action against a patient's face when positive pressure is applied within the mask. Similar to the previous type of seal-forming portion, if the fit between the face and the mask is not good, additional force can be required to achieve a seal, or the mask can leak. Furthermore, if the shape of the seal-forming structure does not match the shape of the patient, it can fold or buckle in use, causing a leak.

[0047] Another type of seal-forming structure can include a friction fit element, for example for insertion into a nare, however some patients find these uncomfortable.

[0048] Another form of seal-forming structure can use an adhesive to achieve a seal. Some patients can find it inconvenient to apply and remove adhesive from their face on a regular basis.

[0049] A range of patient interface seal-forming structure technologies are disclosed in the following patent applications assigned to ResMed Limited: WO 1998 / 004,310; WO 2006 / 074,513; WO 2010 / 135,785.

[0050] ResMed Limited has manufactured the following products incorporating nasal pillows: SWIFT® LT TM Nasal pillow mask, SWIFT® TM II Nasal pillow mask, SWIFT® TM LT Nasal pillow mask, SWIFT® TM FX Nasal pillow mask and MIRAGE LIBERTY TM Full face mask. The following patent applications assigned to ResMed Limited describe examples of nasal pillow masks: International Patent Application WO 2004 / 073,778 (which describes aspects of the ResMed Limited SWIFT® TM nasal pillow), US Patent Application 2009 / 0044808 (which describes aspects of the ResMed Limited SWIFT® TM LT nasal pillow); International Patent Application WO 2005 / 063,328 and WO 2006 / 130,903 (which describe aspects of the ResMed Limited MIRAGE LIBERTY® TM full face mask); International Patent Application WO 2009 / 052,560 (which describes aspects of the ResMed Limited SWIFT® TM FX nasal pillow).

[0051] 2.2.3.1.2 Positioning and stabilisation

[0052] Seal-forming structures of patient interfaces for positive air pressure therapy are subject to a corresponding force of the air pressure to break the seal. Accordingly, various techniques have been used to position the seal-forming structure and maintain it in sealing relationship with the appropriate portion of the face.

[0053] One technique is to use an adhesive. See for example US Patent Application Publication US 2010 / 0000534. However, the use of adhesive can be uncomfortable for some people.

[0054] Another technique is to use one or more straps and / or stabilizing harnesses. Many such harnesses suffer from one or more of the following problems: unsuitability, bulkiness, discomfort, and inconvenience of use.

[0055] An alternative type of treatment system includes a patient interface in which a tube or a substantially hollow, elongated structure for delivering pressurized air to the patient's airway also serves as part of the structure to position and stabilize a sealing portion of the patient interface to the appropriate part of the patient's face, also known as a headband. This means that the helmet forms part of the air circuit. For the purposes of this specification, the terms "tube" and "duct" should be considered to have the same meaning unless the context clearly indicates otherwise.

[0056] This type of patient interface may be referred to as a combination of a 'headband tube' or a 'catheter headband'. Unless the context otherwise requires, these terms are to be understood to be interchangeable for the purposes of this specification. Such a patient interface allows a catheter in the air circuit providing a pressurized airflow from a respiratory pressure therapy device to be connected to the patient interface at a location other than in front of the patient's face. One example of such a treatment system disclosed in U.S. Patent Publication 2007 / 0246043, the contents of which are incorporated herein by reference, involves a catheter connected to the patient interface via a port positioned on the top of the patient's head during use.

[0057] Philips DreamWear TM The mask includes a headband / headband tube. DreamWear is not adjustable. TM The length of the headband tube. Therefore, three different sizes of DreamWear are available. TM Headbands are designed to fit the faces of patients of different sizes. Offering a greater number of different sizes increases the complexity and cost of manufacturing headbands and can result in larger packages. Additionally, the availability of discrete-size face masks may limit the extent to which different sized patients' heads can be accommodated. If forced to choose between discrete sizes with non-adjustable lengths, some patients may have a greater chance of not achieving what they perceive as a comfortable fit.

[0058] 2.2.3.2 Respiratory Pressure Therapy (RPT) Device

[0059] Respiratory pressure therapy (RPT) devices can be used to deliver one or more of the aforementioned treatments, for example, by generating an airflow for delivery to the airway inlet. This airflow can be pressurized. Examples of RPT devices include CPAP devices and ventilators.

[0060] Air pressure generators are known in the range of applications such as industrial scale ventilation systems. However, air pressure generators for medical applications have specific requirements that are not met by more general air pressure generators, such as reliability, size and weight requirements of medical devices. Furthermore, even devices designed for medical use can suffer from drawbacks relating to one or more of comfort, noise, ease of use, efficacy, size, weight, manufacturability, cost and reliability.

[0061] One example of a particular requirement for certain RPT devices is noise.

[0062] A table of noise output levels for existing RPT devices (only a sample, measured at 10 cmH20 using the test method specified in ISO 3744 in CPAP mode).

[0063] RPT device name A-weighted sound pressure level dB(A) year (approx.) C Series Tango TM ]]> 31.9 2007 C Series Tango with humidifier TM ]]> 33.1 2007 S8 Escape TM II]] 30.5 2005 H4i TM S8 Escape TM II]] 31.1 2005 [S9 AutoSet TM ]]> 26.5 2010 S9 AutoSet with H5i humidifier TM ]] 28.6 2010

[0064] One known RPT device 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, can provide invasive and non-invasive non- dependent ventilation support for a range of patients to treat a number of conditions such as, but not limited to, NMD, OHS and COPD. TM

[0065] ResMed Elisée TM 150 Ventilator and ResMed VS III TM Ventilators can provide support for invasive and non-invasive dependent ventilation for adult or paediatric patients for treating a number of conditions. These ventilators provide volume and pressure ventilation modes with a single limb circuit or dual limb circuit. RPT devices generally 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 can be supplied to the airway of a 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.

[0066] Innumerable choices can be presented to the designer of a device. Design criteria often conflict, meaning that certain design choices are far from conventional or inevitable. Furthermore, comfort and efficacy in some areas can be highly sensitive to minor variations in one or more parameters.

[0067] 2.2.3.3 Humidifier

[0068] ​Delivery of a flow of air without humidification can cause drying of the airways. The use of a humidifier with an RPT device and patient interface generates humidified gas that minimizes drying of the nasal mucosa and increases patient airway comfort. In addition, in cooler climates, warm air applied generally into and around the facial area of the patient interface is more comfortable than cold air.

[0069] Many artificial humidification devices and systems are known, however they do not meet the special requirements of medical humidifiers.

[0070] Medical humidifiers are used when required to increase the humidity, temperature (or both) of a flow of air relative to ambient air, typically with the patient asleep or resting (e.g. in a hospital). A bedside placed medical humidifier can be small. A medical humidifier can 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, air conditioner, evaporative cooler, etc.) can also humidify air inhaled by a patient, however these systems also humidify and / or heat the entire room, which can make the occupants uncomfortable. In addition, medical humidifiers can have more stringent safety constraints than industrial humidifiers.

[0071] While many medical humidifiers are known, they can have one or more shortcomings. Some medical humidifiers can provide insufficient humidification, some are difficult or inconvenient for patients to use.

[0072] 2.2.3.4 Vent Technologies

[0073] Some forms of therapy systems can include a vent to allow flushing of exhaled carbon dioxide. The vent can allow gas to flow from an interior space of the patient interface (e.g. a plenum chamber) to an exterior space of the patient interface, e.g. to ambient.

[0074] The vent can include an orifice and in use of the mask gas can flow through the orifice. Many such vents are noisy. Others can become obstructed during use, providing inadequate flushing. Some vents can disturb the sleep of a bed partner 1100 of the patient 1000, e.g. by noise or focussing of gas flow.

[0075] Resmed Limited has developed a number of improved mask vent technologies. See International Patent Application Publication No. WO 1998 / 34,665; International Patent Application Publication No. WO 2000 / 078,381; US Patent No. 6,581,594; US Patent Application Publication No. US 2009 / 0050156; US Patent Application Publication No. 2009 / 0044808.

[0076] Noise figure of existing mask (ISO 17510-2:2007, 10 cm H20 pressure at 1 m)

[0077]

[0078]

[0079] (only one sample, measured at 10 cm H20 in CPAP mode using test method specified in ISO 3744).

[0080] The sound pressure values for various objects are listed below

[0081] SUMMARY

[0082] The present technology relates to providing a medical device for diagnosing, ameliorating, treating or preventing a respiratory disorder, with one or more of improved comfort, cost, efficacy, ease of use, and manufacturability.

[0083] A first aspect of the present technology relates to apparatus for diagnosing, ameliorating, treating or preventing a respiratory disorder.

[0084] Another aspect of the present technology relates to methods for diagnosing, ameliorating, treating or preventing a respiratory disorder.

[0085] One aspect of certain forms of the present technology is to provide methods and / or apparatus to improve patient compliance with respiratory therapy.

[0086] One aspect of the present technology relates to a patient interface comprising an inflation structure, a seal-forming structure, and a positioning and stabilising structure configured to support the seal-forming structure and the inflation structure on a patient's head. The patient interface can include a vent system.

[0087] Another aspect of the present technology relates to a patient interface configured to deliver a flow of pressurised breathing gas to an airway of a patient. The patient interface can include a brace base configured to support a patient's nose in use, and two protrusions extending from the brace base and configured to insert into the patient's nostrils in use.

[0088] Another aspect of the technology relates to a seal-forming structure for a patient interface, the seal-forming structure being configured to form a seal with a nare of a patient. The seal-forming structure can include a base portion and two protrusions provided to the base portion, each of the protrusions having one opening formed therein, the openings being configured to allow a continuous flow of air therethrough. In example forms of the technology, the protrusions are structured and arranged to be inserted or partially inserted into respective ones of the patient's nare in use. The protrusions can be structured and arranged to seal with an inner periphery of the respective nare in use. The protrusions can include end portions that seal with the inner periphery of the respective nare in use.

[0089] In an example, the base portion further includes lateral extensions extending laterally outward on either side of the two protrusions, the lateral extensions being respectively configured to seal against a side or a lower portion of each of the patient's alae nasi in use.

[0090] In an example, the base portion is formed such that, in the absence of any force acting on the base portion, the base portion has a positive curvature in the lateral direction, and wherein, when worn by the patient, engagement of the base portion with the nose reduces the positive curvature of the base portion.

[0091] Another aspect of the technology relates to a seal-forming structure for a patient interface, the seal-forming structure being configured to form a seal with a nare of a patient. The seal-forming structure can include a base portion and at least one opening in the base portion, the at least one opening being configured to allow a continuous flow of air therethrough. In example forms of the technology, the base portion is provided to a plenum chamber. A portion of the base portion and / or a portion of the plenum chamber can form one or more folds. In an example, the seal-forming structure includes two protrusions provided to the base portion, each of the protrusions having one of the openings formed therein.

[0092] One aspect of the present technology is directed to a patient interface comprising: a plenum chamber pressurisable to a therapeutic pressure of at least 6 cmH20 above ambient air pressure, said plenum chamber including a plenum chamber inlet port sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient, a seal-forming structure constructed and arranged to form a seal with a region of the patient’s face surrounding an entrance to the patient’s airways, the seal-forming structure constructed and arranged to maintain said therapeutic pressure in the plenum chamber throughout a patient’s respiratory cycle in use; a vent structure configured to allow a continuous flow of gases exhaled by the patient from an interior of the plenum chamber to ambient, the vent structure being sized and shaped to maintain the therapeutic pressure in the plenum chamber in use; wherein the seal-forming structure further comprises a base portion and two protrusions provided to the base portion, each of the protrusions having one opening formed therein, the openings being configured to allow a continuous flow of air therethrough, the protrusions being constructed and arranged to be inserted or partially inserted into respective ones of the patient’s nares in use so as to provide a flow of air at the therapeutic pressure to the patient’s nares.

[0093] One aspect of the present technology is directed to a patient interface comprising: a plenum chamber pressurisable to a therapeutic pressure of at least 6 cmH20 above ambient air pressure, said plenum chamber including a plenum chamber inlet port sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient, a seal-forming structure constructed and arranged to form a seal with a region of the patient’s face surrounding an entrance to the patient’s airways, the seal-forming structure constructed and arranged to maintain said therapeutic pressure in the plenum chamber throughout a patient’s respiratory cycle in use; a vent structure configured to allow a continuous flow of gases exhaled by the patient from an interior of the plenum chamber to ambient, the vent structure being sized and shaped to maintain the therapeutic pressure in the plenum chamber in use; wherein the seal-forming structure comprises a base portion and at least one opening in the base portion, the at least one opening being configured to provide a flow of air at the therapeutic pressure to the patient’s nares in use, wherein the base portion is provided to the plenum chamber and a portion of the base portion and / or a portion of the plenum chamber forms one or more folds. In an example, the seal-forming structure comprises two protrusions provided to the base portion, each of the protrusions having one of the openings formed therein.

[0094] In an example, the base portion further comprises lateral extensions extending laterally outward on either side of the two protrusions, the lateral extensions being configured to seal against a side or a lower portion of each of the patient’s nasal wings, respectively, in use.

[0095] In an example, the base portion is formed such that, in the absence of any force acting on the base portion, the base portion has a positive curvature, and wherein, when worn by the patient, engagement of the base portion with the nose reduces the positive curvature of the base portion.

[0096] In an example, the patient interface further comprises a positioning and stabilising structure providing a force to hold the seal-forming structure in a therapeutically effective position on the patient's head. In an example, the positioning and stabilising structure comprises a tie, the tie being constructed and arranged so that, in use, at least a portion overlies an area of the patient's head superior to the patient's otobasion superior. In another example, the positioning and stabilising structure comprises at least one gas delivery tube constructed and arranged to contact, in use, at least one area of the patient's head superior to the patient's otobasion superior, wherein the portion of the gas delivery tube superior to the patient's otobasion superior comprises or is provided with a connection port configured for receiving a flow of air from an air circuit and delivering the flow of air to the entrance of the patient's airways via the seal-forming structure.

[0097] Another aspect of one form of the present technology is a patient interface that is molded or otherwise constructed to have a peripheral shape that is complementary to the peripheral shape of an intended wearer.

[0098] One aspect of one form of the present technology is a method of manufacturing a device.

[0099] One aspect of certain forms of the present technology is a medical device that is easy to use, for example by a person without medical training, by a person with limited dexterity, by a person with limited vision, or by a person with limited experience in using medical devices of this type.

[0100] One aspect of one form of the present technology is a patient interface that can be washed in soapy water at a patient's home, for example, without the need for specialised cleaning equipment. One aspect of one form of the present technology is a humidifier tank that can be washed in soapy water at a patient's home, for example, without the need for specialised cleaning equipment.

[0101] Another aspect of the technology includes a patient interface configured to deliver a flow of pressurized breathing gas to an airway of a patient. The patient interface can include a cradle base configured to support a patient's nose in use. Two protrusions can extend from the cradle base and can be configured to be inserted into the patient's nostrils in use. Each protrusion can have an opening formed therein configured to allow a continuous flow of air therethrough. An inflatable base can form an inflatable chamber with the cradle base. The cradle base can be configured such that movement of the cradle base is decoupled from the inflatable base.

[0102] The protrusions can be constructed and arranged to seal against an inner periphery of the respective naris in use. Further, the protrusions can include an end that seals against an inner periphery of the respective naris in use.

[0103] The cradle base can include lateral extensions that extend laterally outward on either side of the two protrusions. The lateral extensions can be configured to seal against a lateral or lower portion of each patient's ala in use, respectively. Additionally, the cradle base can be configured to flex outward by the patient's nose when donned by the patient.

[0104] The protrusions can have a frustoconical shape. Further, the openings of the protrusions can be angled relative to the portion of the cradle base surface from which the protrusions extend.

[0105] The plenum base can include a pair of air inlets on opposite lateral sides. Additionally, the plenum base and the cradle base can be inflatable.

[0106] The bumper or damper between the cradle base and the plenum base can be configured to decouple motion of the cradle base from the plenum base. The bumper or damper can not be configured to decouple motion between two sealing surfaces. Also, the bumper or damper can not be configured to decouple motion between a nasal seal and an oral seal. The patient interface can not include an oral seal. Also, the protrusions can not include a stem.

[0107] Another aspect of the technology includes a patient interface configured to deliver a flow of pressurized breathing gas to an airway of a patient. The patient interface can include a plenum base and a cradle base connected to the plenum base. The plenum base can be configured to support a patient's nose in use. The plenum base and the cradle base can together form a plenum chamber. A channel in a surface of the plenum base adjacent to the cradle base can be configured to decouple motion of the cradle base from the plenum base. Additionally, a pair of protrusions can extend from the cradle base. The pair of protrusions can be configured to be inserted into naris of a patient in use. The pair of protrusions can form a flow path from the plenum chamber to the airway of the patient in use.

[0108] The channel can completely surround the cradle base. Additionally, the cradle base can be U-shaped or V-shaped. The plenum base and the cradle base can be inflatable. Also, lateral portions of the cradle base can be configured to flex toward and away from the plenum base.

[0109] Each protrusion can extend from a respective one of the lateral portions of the cradle base. The lateral portions of the cradle base can extend laterally beyond the respective one of the protrusions.

[0110] The plenum base can include a pair of gas inlets. Each gas inlet can be located on a respective side of the plenum base.

[0111] Each protrusion can be configured to seal an interior of a patient's naris. Also, the cradle base can be configured to seal an exterior surface of a patient's naris.

[0112] Another aspect of the technology includes a patient interface configured to deliver a flow of pressurized breathing gas to an airway of a patient. The patient interface can include a plenum chamber pressurizable to a therapeutic pressure of at least 6 cmH20 above ambient air pressure. The plenum chamber can include a plenum chamber inlet port sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient. A seal-forming structure can be constructed and arranged to form a seal with a region of the patient's face surrounding, and an interior of, the patient's nares. The seal-forming structure can be constructed and arranged to maintain the therapeutic pressure in the plenum chamber throughout the patient's respiratory cycle in use. A spring or damper can be located between the plenum chamber and the seal-forming structure. The spring or damper can be configured to decouple motion of the seal-forming structure from the plenum chamber. The seal-forming structure can further include a cradle base and two protrusions disposed on the cradle base. Each protrusion can have an opening formed therein configured to allow a continuous flow of air therethrough. The protrusions can be constructed and arranged to be inserted or partially inserted into respective ones of the patient's nares in use to provide the flow of air at the therapeutic pressure to the patient's nares.

[0113] The protrusions can be configured to form a seal with an interior of the patient's nares. Further, in use, the cradle base can be configured to support the patient's nose and form a seal with a surface outside of the patient's nares.

[0114] Only a central portion of the cradle base can be attached to the plenum chamber. Lateral portions of the cradle base can flex toward and away from the plenum chamber. Further, the protrusions can be angled relative to a surface of the cradle base from which the protrusions extend.

[0115] Another aspect of the technology includes a patient interface configured to deliver a flow of pressurized breathing gas to the airways of a patient. The patient interface can include a plenum chamber pressurizable to a therapeutic pressure of at least 6 cmH20 above ambient air pressure. The plenum chamber can include an inlet port sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient. A seal-forming structure can be constructed and arranged to form a seal with a region of the patient's face surrounding the patient's nares and the patient's nasal cavities. The seal-forming structure can be constructed and arranged to maintain the therapeutic pressure in the plenum chamber throughout the patient's respiratory cycle while in use. The seal-forming structure can include a cradle base and a pair of protrusions extending from the cradle base. Each protrusion can have an opening formed therein configured to deliver the flow of air at the therapeutic pressure to a naris of the patient when in use. Each protrusion can be configured to be inserted or partially inserted into one of the patient's nares when in use. The cradle base can be supported on the plenum chamber, and a portion of the cradle base and / or a portion of the plenum chamber can form one or more folds configured to decouple motion of the cradle base from the plenum chamber.

[0116] The one or more folds can be part of an accordion structure. Further, the cradle base can further include lateral extensions extending laterally outward on either side of the protrusions. The lateral extensions can be configured to seal against the lateral or inferior portions of each patient's ala, respectively, when in use.

[0117] The patient interface can further include a positioning and stabilising structure to provide a force to hold the seal-forming structure in a therapeutically effective position on the patient's head. The positioning and stabilising structure can include a tie, the tie being constructed and arranged so that at least a portion overlies a region of the patient's head superior to an otobasion superior of the patient's head when in use. The positioning and stabilising structure can also include at least one gas delivery tube, the gas delivery tube being constructed and arranged to contact a region of the patient's head superior to an otobasion superior of the patient's head when in use. The portion of the gas delivery tube superior to an otobasion superior of the patient's head can include or be provided with a connection port configured to receive a flow of air from an air circuit and deliver the flow of air to an entrance of the patient's airways via the seal-forming structure.

[0118] Of course, parts of these aspects can form sub-aspects of the technology. The sub-aspects and / or various aspects of the aspects can be combined in various ways and also form further aspects or sub-aspects of the technology.

[0119] Other features of the technology will be apparent from consideration of the following detailed description, abstract, drawings and claims. BRIEF DESCRIPTION OF DRAWINGS

[0120] The technology is illustrated by way of example, and not by way of limitation, in the accompanying drawings of which:

[0121] 4.1 Therapy system

[0122] Figure 1A A system is shown including a patient 1000 wearing a patient interface 3000 as a nasal pillows receives a supply of air at positive pressure from an RPT device 4000. Air from the RPT device 4000 is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000. A bed partner 1100 is also shown. The patient is sleeping in a supine sleeping position.

[0123] Figure 1B A system is shown including a patient 1000 wearing a patient interface 3000 as a nasal mask receives a supply of air at positive pressure from an RPT device 4000. Air from the RPT device is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000.

[0124] Figure 1C A system is shown including a patient 1000 wearing a patient interface 3000 as a full face mask receives a supply of air at positive pressure from an RPT device 4000. Air from the RPT device is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000. The patient is sleeping in a side sleeping position.

[0125] 4.2 Respiratory system and facial anatomy

[0126] Figure 2A A diagrammatic view of the human respiratory system is shown, including nasal cavities and oral cavities, larynx, vocal folds, oesophagus, trachea, bronchi, lungs, alveolar sacs, heart and diaphragm.

[0127] Figure 2B A view of the upper airways of a human is shown, including nasal cavities, nasal bones, nasal cartilages, alar cartilages, nostrils, upper lip, lower lip, larynx, hard palate, soft palate, oropharynx, tongue, epiglottis, vocal folds, oesophagus and trachea.

[0128] Figure 2C is a front view of a face with several surface anatomical features identified, including the upper lip, upper vermilion, lower vermilion, lower lip, mouth width, endocanthion, endo-canthion, nasolabial sulcus and cheilion. Also identified are the superior, inferior, radial-in and radial-out directions.

[0129] Figure 2D is a side view of a head with several surface anatomical features identified, including glabella, sellion, pronasale, subnasale, upper lip, lower lip, supramenton, nasal ridge, alar crest, otobasion superior and otobasion inferior. Also identified are the superior-inferior and anterior-posterior directions.

[0130] Figure 2E is another lateral view of the head. The approximate location of the Frankfort horizontal and nasolabial angle are indicated. The coronal plane is also indicated.

[0131] Figure 2F shows a bottom view of the nose showing several features including the nasolabial sulcus, lower lip, upper vermilion, nostril, subseptal point, columella, pronasale, long axis of the nostril, and the central sagittal plane.

[0132] Figure 2G shows a lateral view of the surface features of the nose.

[0133] Figure 2H shows the subcutaneous structure of the nose including the lateral cartilages, septal cartilage, alar major cartilage, alar minor cartilage, ciliary cartilage, nasal bone, skin, adipose tissue, frontal process of the maxilla, and fibrofatty tissue.

[0134] Figure 2I shows a medial dissection of the nose about several millimeters medial to the central sagittal plane showing, among other things, the medial crura of the septal cartilage and alar major cartilages.

[0135] Figure 2J shows a front view of the skull including the frontal bone, nasal bone, and zygomatic bone. Also indicated are the concha, as well as the maxilla and mandible.

[0136] Figure 2K shows a lateral view of the skull with the surface contours of the head and several muscles. The following bones are shown: frontal, sphenoid, nasal, zygomatic, maxilla, mandible, parietal, temporal, and occipital. The mental protuberance is also indicated. The following muscles are shown: digastric, masseter, sternocleidomastoid, and trapezius.

[0137] Figure 2L shows a front-lateral view of the nose.

[0138] 4.3 Patient interface

[0139] Figure 3A shows a patient interface in the form of a nasal mask in accordance with one form of the present technology.

[0140] Figure 3B shows a schematic view of a cross-section through a structure at a point. The outward normal at the point is indicated. The curvature at the point has a positive sign and a relatively large magnitude when compared to the Figure 3C curvature magnitude shown.

[0141] Figure 3C shows a schematic view of a cross-section through a structure at a point. The outward normal at the point is indicated. The curvature at the point has a positive sign and a relatively large magnitude when compared to theFigure 3B has a relatively small magnitude when compared to the magnitude of the curvature shown.

[0142] Figure 3D A schematic diagram of a cross section through a structure at a point is shown. An outward normal at the point is indicated. The curvature at the point has a zero value.

[0143] Figure 3E A schematic diagram of a cross section through a structure at a point is shown. An outward normal at the point is indicated. The curvature at the point has a negative sign and when compared to the magnitude of the curvature shown Figure 3F has a relatively small magnitude when compared to the magnitude of the curvature shown.

[0144] Figure 3F A schematic diagram of a cross section through a structure at a point is shown. An outward normal at the point is indicated. The curvature at the point has a negative sign and when compared to the magnitude of the curvature shown Figure 3E has a relatively large magnitude when compared to the magnitude of the curvature shown.

[0145] Figure 3G A cushion for a mask comprising two pillows is shown. An outer surface of the cushion is indicated. An edge of the surface is shown. A dome and a saddle region are shown.

[0146] Figure 3H A cushion for a mask is shown. An outer surface of the cushion is indicated. An edge of the surface is shown. A path on the surface between points A and B is indicated. A straight line distance between A and B is indicated. Two saddle regions and a dome region are indicated.

[0147] Figure 3I A surface of a structure with a one-dimensional hole on the surface is shown. The planar curve illustrated forms a boundary of the one-dimensional hole.

[0148] Figure 3J A cross section through a structure of Figure 3I is shown. The surface shown defines a two-dimensional hole in the structure of Figure 3I .

[0149] Figure 3K A perspective view of a structure of Figure 3I is shown, including a two-dimensional hole and a one-dimensional hole. Also shown is a surface that bounds the two-dimensional hole in the structure of Figure 3I .

[0150] Figure 3L A mask with an inflatable bladder as a cushion is shown.

[0151] Figure 3M A cross section through a mask of Figure 3L is shown, and an inner surface of the bladder is shown. The inner surface bounds a two-dimensional hole in the mask.

[0152] Figure 3N Another cross-section of the mask of Figure 3L is shown. The inner surface is also indicated.

[0153] Figure 3O The left-hand rule is shown.

[0154] Figure 3P The right-hand rule is shown.

[0155] Figure 3Q The left ear is shown, including the left ear screw.

[0156] Figure 3R The right ear is shown, including the right ear screw.

[0157] Figure 3S The right-hand screw is shown.

[0158] Figure 3T A view of the mask is shown, including the notation of the twist of the space curve defined by the edge of the sealing membrane in different regions of the mask.

[0159] Figure 3U A view of the plenum (cushion assembly) 3200 is shown, showing the sagittal plane and the mid-contact plane.

[0160] Figure 3V A view of the back of the plenum of Figure 3U is shown. The view is in a direction normal to the mid-contact plane. Figure 3V The sagittal plane in bisects the plenum into a left side and a right side.

[0161] Figure 3W A cross-section through the plenum of Figure 3V is shown, taken at the sagittal plane shown in Figure 3V . The "mid-contact" plane is shown. This mid-contact plane is normal to the sagittal plane. The orientation of the mid-contact plane corresponds to the orientation of the chord 3210, which lies on the sagittal plane and just touches the cushion of the plenum at two points on the sagittal plane: an upper point 3220 and a lower point 3230. Depending on the geometry of the cushion in this region, the mid-contact plane can be a tangent at the upper and lower points.

[0162] Figure 3X A position of the plenum 3200 of Figure 3U in use on a face is shown. When the plenum is in the position of use, the sagittal plane of the plenum 3200 coincides approximately with the median sagittal plane of the face. When the plenum is in the position of use, the mid-contact plane corresponds generally to the 'face plane'. In Figure 3X , the plenum 3200 is the plenum of a nasal mask, and the upper point 3220 is located approximately at the nasion, while the lower point 3230 is located on the upper lip.

[0163] Figure 3Y A front perspective view of a patient interface according to an aspect of the present technology is shown.

[0164] Figure 3Z A front upper view of a patient interface according to another aspect of the present technology is shown.

[0165] Figure 3AA A side view of a patient interface according to another aspect of the present technology is shown.

[0166] Figure 3BB A side view of a patient interface according to another aspect of the present technology is shown.

[0167] Figure 3CC A side view of a patient interface according to another aspect of the present technology is shown.

[0168] Figure 3DD A plan view of a foam layer is depicted.

[0169] Figure 3EE A front perspective view of a patient interface according to another aspect of the present technology is shown.

[0170] Figure 3FF A front upper view of a patient interface according to another aspect of the present technology is shown. Figure 3EE

[0171] 4.4 RPT device

[0172] Figure 4A An RPT device according to one form of the present technology is shown.

[0173] Figure 4B is a schematic diagram of the pneumatic path of an RPT device according to one form of the present technology. The direction of upstream and downstream is indicated with reference to the air mover and the patient interface. The air mover is defined as being upstream of the patient interface and the patient interface is defined as being downstream of the air mover, irrespective of the actual direction of flow at any particular instant. Items located within the pneumatic path between the air mover and the patient interface are downstream of the air mover and upstream of the patient interface.

[0174] 4.5 Humidifier

[0175] Figure 5A An isometric view of a humidifier according to one form of the present technology is shown.

[0176] Figure 5B An isometric view of a humidifier according to one form of the present technology is shown, showing the humidifier reservoir 5110 removed from the humidifier reservoir base 5130.

[0177] 4.6 Breathing waveforms

[0178] ​Figure 6 A model typical respiratory waveform of a human during sleep is shown. DETAILED DESCRIPTION

[0179] Before the present technology is described in further detail, it is to be understood that the technology is not limited to the particular examples described herein, which can vary. It is also to be understood that the terminology used herein is for the purpose of describing particular examples only, and is not intended to be limiting.

[0180] The following description provides various examples, which relate to what can share one or more common characteristics and / or features. It should be understood that one or more features of any one example can be combinable with one or more features of another or other examples. In addition, any single feature or combination of features in any of the examples can constitute additional examples.

[0181] 5.1 Treatment

[0182] In one form, the technology comprises a method for treating a respiratory disorder, the method including the step of applying positive pressure to an entrance of the airways of a patient 1000.

[0183] In certain examples of the technology, the supply of air at positive pressure is provided to the patient's nares via one or both nares.

[0184] In certain examples of the technology, oral breathing is limited, restricted or prevented.

[0185] 5.2 Treatment system

[0186] In one form, the technology comprises an apparatus or device for treating a respiratory disorder. The apparatus or device can comprise an RPT device 4000 for supplying pressurized air to a patient 1000 via a air circuit 4170 to a patient interface 3000.

[0187] 5.3 Patient interface

[0188] A non-invasive patient interface 3000 according to an aspect of the technology comprises the following functional aspects: a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilising structure 3300, a vent 3400, a form of connection port 3600 for connection to an air circuit 4170, and a forehead support 3700. In some forms, a functional aspect can be provided by one or more physical components. In some forms, one physical component can provide one or more functional aspects. In use, the seal-forming structure 3100 is arranged to surround an entrance to the airways of a patient so as to facilitate the supply of air at positive pressure to the airways.

[0189] A patient interface can not be suitable for respiratory pressure therapy if it does not comfortably deliver a minimum level of positive pressure to the airways.

[0190] A patient interface 3000 according to an form of the present technology is constructed and arranged to be capable of supplying air at a positive pressure of at least 6 cmH20 relative to ambient.

[0191] A patient interface 3000 according to an form of the present technology is constructed and arranged to be capable of supplying air at a positive pressure of at least 10 cm H20 relative to ambient.

[0192] A patient interface 3000 according to an form of the present technology is constructed and arranged to be capable of supplying air at a positive pressure of at least 20 cm H20 relative to ambient.

[0193] 5.3.1 Seal-forming structure

[0194] In an form of the present technology, the seal-forming structure 3100 provides a target seal-forming region and can additionally provide a cushioning function. The target seal-forming region is the region of the seal-forming structure 3100 upon which a seal is intended to occur. The region where a seal actually occurs - the actual sealing surface - can vary from day to day and from patient to patient, depending on a range of factors including, for example, the position of the patient interface on the face, the tension in the positioning and stabilising structure, and the shape of the patient's face.

[0195] In an form, the target seal-forming region is located on an outer surface of the seal-forming structure 3100.

[0196] In certain forms of the present technology, the seal-forming structure 3100 is constructed from a biocompatible material, for example silicone rubber.

[0197] A seal-forming structure 3100 according to the present technology can be constructed from a soft, flexible and resilient material such as silicone.

[0198] In certain forms of the present technology, a system is provided that includes more than one seal-forming structure 3100, each seal-forming structure configured to correspond to a different size and / or shape range. For example, the system can include one form of seal-forming structure 3100 that is suitable for a large size head but not a small size head, and another that is suitable for a small size head but not a large size head.

[0199] 5.3.1.1 Seal-forming mechanism

[0200] In one form, the seal-forming structure includes a seal flange that utilizes a pressure-assisted sealing mechanism. In use, the seal flange is able to readily respond to the system positive pressure acting on its underside from within the plenum chamber 3200, thereby causing it to form a tight sealing engagement with the face. This pressure-assisted mechanism can act in conjunction with the resilient tension in the positioning and stabilising structure.

[0201] In one form, the seal-forming structure can include a compression seal portion or a gasket seal portion. In use, the compression seal portion or the gasket seal portion is configured and arranged to be in compression, for example as a result of the resilient tension in the positioning and stabilising structure.

[0202] In one form, the seal-forming structure includes a tensioned portion. In use, the tensioned portion is held in tension, for example by adjacent regions of the seal flange.

[0203] In one form, the seal-forming structure includes a region having a tacky or adhesive surface.

[0204] In certain forms of the present technology, the seal-forming structure can include one or more of a pressure-assisted seal flange, a compression seal portion, a gasket seal portion, a tensioned portion, and a portion having a tacky or adhesive surface.

[0205] 5.3.1.2 Nasal Seal

[0206] Figures 3Y to 3CC A patient interface 3000 including a seal-forming structure 3100 and a plenum chamber 3105 according to another aspect of the present technology is depicted. A damper or bumper 3106 can be located between the seal-forming structure 3100 and the plenum chamber 3105 to decouple motion of the seal-forming structure 3100 from the plenum chamber 3105.

[0207] The seal-forming structure 3100 of the patient interface 3000 can be a nasal cradle having an anchor configured to anchor the nasal cradle to a nare of the patient. Each seal-forming structure 3100 can include a pair of protrusions 3110 extending from a cradle base 3120. The protrusions 3110 can be structured and arranged to form a seal with a respective nare of the patient's nose. Alternatively, the protrusions 3110 can only engage a portion of the patient's nare and can not form a seal with the nare of the patient's nose.

[0208] The protrusions 3110 can be structured and arranged to be inserted or partially inserted into a respective one of the patient's nares in use. Each protrusion 3110 can be hollow and can have an opening 3130 at a distal end of the protrusion 3110. Each protrusion 3110 can be configured to allow a continuous pressurised flow of breathing gas therethrough, such that the pressurised flow of breathing gas can enter the patient's nares when the patient interface 3000 is worn.

[0209] In certain forms of the technology, each protrusion 3110 can be configured to extend partially into a corresponding one of the patient's nares. For example, each protrusion 3110 can be constructed and arranged to engage and seal (or just engage) with an inner periphery of the respective naris in use. The height of each protrusion 3110 from the cradle base 3120 can be less than a conventional nasal pillow patient interface. For example, the height of each protrusion 3110 from the cradle base 3120 can be less than 2 cm. It is envisaged that the height of each protrusion 3110 from the cradle base 3120 can be less than 1 cm. It is also envisaged that the height of the protrusions 3110 from the cradle base 3120 can be less than 0.5 cm. The tip (or edge) of each protrusion 3110 forming the opening 3130 can be configured to engage and seal (or just engage) against the inner periphery of the corresponding naris.

[0210] Each protrusion 3110 can have a base end 3140 proximal to the cradle base 3120 and an exit end 3150 opposite the base end 3140. The opening 3130 can be at the exit end 3150. The peripheral wall 3160 of the protrusion 3110 can form a gas passageway for the pressurised flow of breathing gas, given the hollow structure of the protrusion 3110.

[0211] Each protrusion 3110 can be tapered such that the footprint of the protrusion 3110 is greatest at the base end 3140 and least at the exit end 3150. The structure of the protrusion 3110 can differ from a conventional nasal pillow by eliminating a thinner stem portion between the widest portion and the base, which allows the nasal pillow to flex and / or bend significantly relative to its base. Removing the stem portion can minimise relative movement between the protrusion 3110 and the surface of the cradle base 3120 from which the protrusion 3110 extends, thereby facilitating anchoring of the protrusion 3110.

[0212] It is envisaged that the protrusions 3110 can have a frustoconical or similar shape. For example, as shown in Figs. 13A and 13B, the peripheral wall 3160 of the protrusion 3110 can taper from the base end 3140 towards the exit end 3150, while the cross-sectional shape of the protrusion 3110 can be elliptical rather than circular. It is also envisaged that the shape of the protrusion 3110 is not limited to the shape shown in Figs. 13A and 13B. For example, the cross-sectional shape of the protrusion 3110 can be circular, rectangular, triangular, or any combination thereof. It is envisaged that the cross-sectional shape can be open on at least one side. For example, the cross-sectional shape can be C-shaped. For configurations in which the cross-sectional shape is open on at least one side, the protrusion 3110 can not form part of the gas flow path. Rather, the protrusion 3110 can serve only to anchor the seal-forming structure 3100 to the patient's nose. Figure 3Y 3Z Figure 3Y 3Z

[0213] ​​​​Alternatively, the perimeter wall 3160 of the protrusion 3110 can not be tapered, and the footprint of the protrusion 3110 is uniform from the base end 3140 to the exit end 3150. It is also contemplated that there can be more than one perimeter wall 3160 (depending on the cross-sectional shape of the protrusion 3110).

[0214] As shown, the opening 3130 can extend along a plane 3170. Further, the protrusion 3110 can have a longitudinal axis 3175 that is perpendicular to the plane 3170 and extends through the base end and exit end 3140, 3150 of the protrusion 3110. Further, the perimeter wall 3160 can taper at an angle a with respect to the longitudinal axis 3175. The taper angle a can vary in a direction perpendicular to the longitudinal axis 3175. For example, the taper angle a of the perimeter wall 3160 can be smallest at a center-facing side 3180 of the protrusion 3110 (i.e., the side of the protrusion 3110 closest to another protrusion 3110). Meanwhile, the taper angle a of the perimeter wall 3160 can be largest at an outward-facing side 3190 of the protrusion 3110 (i.e., the side of the protrusion 3110 farthest from another protrusion 3110). In this configuration, the length of the perimeter wall 3160 from the base end 3140 to the exit end 3150 can be greatest at the center-facing side 3180 and smallest at the outward-facing side 3190. Figure 3BB

[0215] By varying the taper angle a, the protrusion 3110 and the opening 3130 can be angled with respect to the portion of the cradle base 3120 from which the protrusion 3110 extends. The portion of the protrusion 3110 of the cradle base 3120 that can be angled with respect to the opening in the patient’s nare. Thus, angling the protrusion 3110 and the opening 3130 with respect to the cradle base 3120 can allow the protrusion 3110 to align with the patient’s nare such that the entirety of the exit end 3150 is received within the patient’s nare.

[0216] Alternatively, the taper angle a can be uniform in a direction perpendicular to the longitudinal axis 3175. In this configuration, the length of the perimeter wall 2160 from the base end 3140 to the exit end 3150 can be the same at the center-facing side 3180 and the outward-facing side 3190.

[0217] It is contemplated that the opening 3130 can have an elliptical shape, which can more easily conform to the shape of the patient’s nare. However, it should be understood that the opening 3130 can be any other shape, such as a circular shape.

[0218] ​The protrusions 3110 can improve seal stability. For example, in use, the protrusions 3110 can be positioned in contact with the outer periphery of the patient's nares, and can serve to position the brace base 3120, and by extension, the patient interface 3000 in the intended position on the patient's face, and to maintain the patient interface 3000 in that position during use. In other words, the protrusions 3110 can be configured to prevent lateral movement of the patient interface 3000 on the patient's face during use.

[0219] To perform the function of anchoring the brace base 3120 to the patient's nares, each protrusion 3110 can need to engage only the open edge of the patient's nasal cavity airway. Thus, the protrusions 3110 can be only long enough to engage the open edge of the patient's nasal cavity airway or the immediate area thereof. In other words, the protrusions 3110 can be designed to not penetrate as far into the patient's nasal cavity as a conventional nasal plug or even a conventional nasal pillow.

[0220] Preferably, the protrusions 3110 do not extend beyond (or far beyond) the edge of the opening of the patient's nasal cavity airway to allow the opening 3140 at the end of the protrusions 3110 to have an increased area. In particular, as the patient's nasal cavity airway extends into the patient's nose, the patient's nasal airway size decreases. Thus, to fit within the patient's nasal cavity airway, the diameter of a conventional nasal plug must decrease towards its distal end, thereby decreasing the size of the opening at the distal end of the nasal plug. By limiting the extent to which the protrusions 3110 extend into the patient's nasal cavity airway, the size of the opening 3140 at the end of the protrusions 3110 can be greater than in the case of a conventional nasal plug. Increasing the size of the opening 3140 can reduce flow restriction and can improve respiratory comfort, while minimising jetting.

[0221] Alternatively, the protrusions 3110 can be designed to penetrate into the patient's nasal cavity passage as far as a conventional nasal plug or nasal pillow (i.e. beyond the immediate vicinity of the edge of the opening of the patient's nasal cavity airway).

[0222] It is envisaged that the brace base 3120 and the protrusions 3110 can be formed from the same material, and in some forms, they can be integrally formed, for example they can be integrally moulded. It is also envisaged that the protrusions 3110 and the brace base 3120 can be made from a flexible material, such as silicone.

[0223] The cradle base 3120 can include a central portion 3240 between a pair of lateral portions 3250. Each protrusion 3110 can be located on a respective lateral portion 3250 such that the protrusions 3110 are located on opposite sides of the central portion 3240. Further, the cradle base 3120 can include a sealing surface 3260 that spans the space between the protrusions 3110 and that surrounds the base end 3140 of the protrusions 3110. Thus, a portion of the sealing surface 3260 of the cradle base 3120 can extend beyond the footprint of the protrusions 3110 and can form an edge 3270 that surrounds the protrusions 3110. The sealing surface 3260 can have a size and orientation such that, when the patient interface 3000 is worn, the sealing surface 3260 (and the edge 3270) can engage the patient’s skin and seal against the sides and / or the lower portion of the patient’s nose.

[0224] Thus, the patient interface 3000 can form first and second seals with the patient’s nose (e.g., a first seal between the inner walls of the patient’s nares and the protrusions 3110 and a second seal between the sealing surface 3260 (and the edge 3270) and the exterior of the patient’s nose). This can improve the quality of the overall seal between the patient interface 3000 and the patient’s face (or nose) and can also stabilize the seal-forming structure in use, thereby reducing the risk of compromising the overall seal during use.

[0225] The cradle base 3120 can be curved and can have a general cradle, cup, U-shape, or V-shape that can cradle the patient’s nose during use. The flexibility of the cradle base 3120 can allow the lateral portions 3250 to bend relative to the central portion 3240 such that the lateral portions 3250 (and the protrusions 3110) can move toward and away from each other.

[0226] As can be seen in Figure 3CC the lateral portions 3250 can be oriented at an angle β relative to a plane 3280 that bisects the patient interface 3000 between the protrusions 3110. In repose (or when not engaged with the patient’s nose), the lateral portions 3250 can be oriented at a preset (or repose) angle β. However, when the patient dons the patient interface 3000, the patient’s nose can cause the lateral portions 3250 (with the protrusions 3110) to bend outward, thereby increasing the angle β. The cradle base 3120 can have a resilient property that biases the lateral portions 3250 toward the preset angle β. The biasing force can cause the lateral portions 3250 to press against (or clamp) the patient’s nose, thereby maintaining a seal to the patient’s nose and stabilizing the patient interface 3000 on the patient’s face.

[0227] It is conceivable that the stent base 3120 may be hollow. It is also conceivable that the material of the stent base 3120 may be expandable and / or flexible, such that supplying pressurized breathing gas into the interior of the stent base 3120 causes the stent base 3120 to expand (i.e., causes the chamber within the stent base 3120 to expand). Inflation of the stent base 3120 forces the sealing surface 3260 against the patient's nose, which maintains a seal against the patient's nose and helps stabilize the patient interface 3000 on the patient's face.

[0228] It is conceivable that different stent bases 3120 can have different sizes, allowing for different rest angles β. Utilizing stent bases 3120 of different sizes and different rest angles β allows for greater design flexibility to accommodate patients with noses and / or mouths of different sizes and / or shapes. For example, a stent base 3120 with a larger rest angle β could be better suited for patients with larger, wider, and / or flatter noses.

[0229] like Figure 3AA and 3DD As shown, the seal-forming structure 3100 may optionally include a foam layer 3285 on the sealing surface 3260. The foam layer 3285 may span the entire sealing surface 3260 and may include openings 3286 for the protrusions 3110. The foam layer 3285 may increase the comfort of the seal-forming structure 3100 and may be made of open-cell or closed-cell foam. It is contemplated that the seal-forming structure 3100 may include a foam layer 3285 without an underlying sealing surface 3260. Further contemplated is that the foam layer 3285 may be replaced with a layer made of fabric material. Alternatively, the foam layer may be encapsulated within an outer skin made of fabric material. Each of these materials is known to enhance tactile comfort compared to elastomeric silicone.

[0230] The foam layer 3285 can be configured to support a seal between the patient interface 3000 and the patient's face. For example, the foam layer 3285 can be adapted to provide a compression seal to the user's face. The compression seal provided by the foam layer 3285 can work in conjunction with the underlying sealing surface 3260 to provide an improved seal, wherein the underlying sealing surface 3260 can bias the foam layer toward the user's face when the seal-forming structure 3100 is internally pressurized. The sealing mechanism can function by providing a combination of compression of the foam material in the foam layer 3285 and can be further supported by the internal pressurization of the seal-forming structure 3100. The foam layer 3285 can also increase patient comfort.

[0231] The foam layer 3285 can be permanently attached to the cradle base 3120 or can be removable from the cradle base 3120. It is contemplated that the foam layer 3285 can be secured to the cradle base 3120 by clips, snaps, adhesive, hook and loop arrangements, or bonding. Additionally, the foam layer 3285 can optionally be in the form of a sleeve that encloses the entirety of the cradle base 3120 with the protrusions 3110 extending through openings 3286. The foam layer 3285 can optionally have one or more flaps 3287. A portion of the securing mechanism (e.g., hook, loop, clip, etc.) can be located on the flaps 3287 while another portion of the securing mechanism (e.g., hook, loop, clip, etc.) can be located on a corresponding location on the cradle base 3120.

[0232] While Figure 3DD Four flaps 3287 are shown, but any number of flaps 3287 can be used (e.g., 1, 2, 3, 4) depending on what is needed to secure the foam layer 3285 over the cradle base 3120. Additionally, the location of the flaps 3287 is not limited to Figure 3DD the locations shown. The flaps 3287 can be positioned in any manner along the perimeter of the foam layer 3285.

[0233] It is also contemplated that the foam layer 3285 can be held in place by the protrusions 3110. In particular, the diameter (or footprint) of the openings 3286 can be slightly smaller than the footprint of the base end 3140 of the protrusions 3110 such that the openings 3286 can be stretched by the protrusions 3110 when fitted onto the cradle base 3120 and can be held in place by the friction between the protrusions 3110 and the edges of the openings 3286.

[0234] It is contemplated that the cradle base 3120 can be generally U-shaped when viewed from the front side during use. The cradle base 3120 can have a positive, negative, or zero curvature in the anterior-posterior direction (i.e., in the sagittal plane). A positive curvature of the cradle base 3120 in the lateral direction can present the protrusions 3110 to the respective nostrils, while the portions of the cradle base 3120 between the protrusions 3110 can be further positioned in the anterior direction to avoid contact with the patient's carina.

[0235] The cradle base 3120 can be configured such that, in the absence of any force acting on the cradle base 3120, the cradle base 3120 can have some amount of positive curvature in the lateral direction, such that when worn by a patient, the engagement of the cradle base 3120 with the nose can reduce the positive curvature of the cradle base 3120. That is, the ‘natural’ or ‘rest’ curvature of the cradle base 3120 can be greater than the curvature of the cradle base 3120 when worn. In examples where the cradle base 3120 is formed from a resilient material, or is configured to elastically return to its original shape when not being worn, the lateral portions 3250 of the cradle base 3120 can be pushed inward against the patient’s nose when the patient interface 3000 is worn. This can assist in forming a seal to the nose and stabilising the patient interface 3000 in the desired position.

[0236] It will be appreciated that different patient interfaces 3000 can include cradle bases 3120 that have different amounts of positive curvature in their ‘rest’ state, in order to cater for patients with noses and / or faces of different sizes and / or shapes.

[0237] The plenum base 3105 can support the cradle base 3120 and the protrusion 3110. Furthermore, the plenum base 3105 and the cradle base 3120 can together form a combined plenum chamber that receives a flow of pressurised breathing gas. A portion of the plenum base 3105 can have a surface shaped to complement the surface profile of an average person’s face in use. In some forms, the plenum base 3105 and the seal-forming structure 3100 can be formed from a single piece of homogenous material, for example silicone.

[0238] In certain forms of the present technology, the plenum base 3105 can be constructed from a transparent material, for example a transparent polycarbonate or silicone material. Alternatively, the plenum base 3105 can be constructed from a translucent material.

[0239] In certain forms of the present technology, the plenum base 3105 can be formed from the same material as the seal-forming structure 3100 and can be integrally formed.

[0240] One or more positioning and stabilising structure connectors (or headgear connectors) 3290 can be provided to the plenum base 3105. The positioning and stabilising structure connectors 3290 are configured to connect to the positioning and stabilising structure 3300 in use. The positioning and stabilising connectors 3290 can be located on opposite lateral sides of the plenum base 3105. It is envisaged that the positioning and stabilising structure connectors 3290 can comprise clips, buckles or any other connector capable of connecting to or being connected to the positioning and stabilising structure 3300, for example headgear straps and headgear conduits.

[0241] The positioning and stabilising structure connector 3290 can be in the form of, or can include, an inlet tube 3310 that protrudes from the side of the plenum 3105. The inlet tube 3310 can be configured to receive pressurised breathing gas from one or more air delivery tubes and / or one or more conduits in the positioning and stabilising structure (or headgear) 3300. It is envisaged that connecting the inlet tube 3310 to an air delivery conduit can simultaneously connect the plenum 3105 (and the patient interface 3000) to the positioning and stabilising structure (or headgear) 3300 when the positioning and stabilising structure (or headgear) 3300 includes a headgear conduit.

[0242] A damper or bumper 3106 can intervene between the cradle base 3120 and the plenum 3105. The damper or bumper 3106 can decouple movement of the cradle base 3120 (and the movement of the protrusions 3110) from the plenum 3105. The damper or bumper 3106 can completely surround the cradle base 3120 or can only partially surround the cradle base 3120. It is envisaged that the lateral portions 3250 of the cradle base 3120 can extend beyond the damper or bumper 3106. Furthermore, the damper or bumper 3106 can be in the form of a channel Figure 3Z ), an accordion Figure 3AA ), a bellows, a spring or other structure capable of decoupling movement of the cradle base 3120 from the plenum 3105.

[0243] The bumper or damper 3106 can absorb side loads acting on the cradle base 3120 before the side loads are transferred to the plenum 3105. It is envisaged that the bumper or damper 3106 can allow the lateral portions 3250 of the cradle base 3120 to flex or move independently of the plenum 3105. It is also envisaged that the plenum 3105 with the bumper or damper 3106 can inflate due to internal pressurisation within the plenum chamber formed by the cradle base 3120 and the plenum 3105. Inflation of the plenum 3105 and the channel 3320 can bias the protrusions 3110 and the sealing surface 3260 against the patient's nose, thereby further supporting the seal formed by the protrusions 3110 and the sealing surface 3260.

[0244] Additionally, the lateral portion 3250 of the support base 3120 may protrude away from the inflatable base 3105 and the buffer or damper 3106, such that only the central portion 3240 is directly attached to the inflatable base 3105. It is conceivable that a portion of the lateral portion 3250 closest to the central portion 3240 may also be directly connected to the inflatable base 3105. Accordingly, at least a portion of the lateral portion 3250 may be separated from the inflatable base 3105 and the buffer or damper 3106, such that the surface 3330 of the lateral portion 3250 opposite the sealing surface 3260 may face the surfaces of the buffer or damper 3106 and / or the inflatable base 3105. The flexibility of the buffer or damper 3106 allows the surface 3330 to move toward and away from the surface of the inflatable base 3105. This flexibility of movement helps maintain a seal on the patient's nose during use.

[0245] The buffer or damper 3106 may be a separate component. Alternatively, the buffer or damper 3106 may be formed within a portion of the support base 3120 and / or the inflatable base 3105 of the sealing structure 3100. As an accordion-type or bellows-type structure, the buffer or damper 3106 may form one or more folds. For example, one or more folds 3340 may be provided in a portion of the support base 3120 connected to and / or adjacent to the inflatable base 3105. One or more folds 3340 may also (or alternatively) be provided in a portion of the inflatable base 3105 connected to and / or adjacent to the support base 3120. As a channel structure, the buffer or damper 3106 may form a recess in the surface of the inflatable base 3105.

[0246] like Figures 3Y-3CC As shown, the support base 3120 can be connected to the inflatable base 3015 along a generally elliptical or elongated region, the extent of which is smaller than the outer extent of the support base 3120. Furthermore, the buffer or damper 3106 can project inward toward the interior of the inflatable chamber portion formed by the inflatable base 3105. In other forms, the buffer or damper 3106 can project outward away from the portion of the inflatable chamber formed by the inflatable base 3105. When the buffer or damper 3106 comprises a hexagonal accordion or bellows structure, portions of the buffer or damper 3106 can project inward, while other portions can project outward.

[0247] A bumper or damper 3106 can be used to at least partially decouple motion of the brace base 3120 from the plenum base 3105 in use. Additionally or alternatively, the bumper or damper 3106 can accommodate different facial structures of patients. Additionally or alternatively, the bumper or damper 3106 can act like a spring such that when the patient wearing the patient interface 3000 deforms and presses the brace base 3120 towards the plenum base 3105, the bumper or damper 3106 can push the brace base 3120 towards the patient's face, thereby helping to maintain the seal-forming structure 3100 in sealing engagement with the patient's face. Additionally or alternatively, the bumper or damper 3106 can be configured to inflate or partially inflate when pressurized air enters the plenum base 3105 and / or the seal-forming structure 3100. This inflation can help to push the brace base 3120 towards the patient's face, thereby helping to maintain the seal-forming structure 3100 in sealing engagement with the patient's face.

[0248] The plenum base 3105 can include vents having one or more openings. Furthermore, the patient interface 3000 can not include a mouth seal or cushion (e.g., a cushion configured to seal around a patient's mouth). Furthermore, the bumper or damper 3106 can not be configured to decouple motion between two sealing surfaces. The bumper or damper 3106 can not be configured to decouple motion between a mouth seal and a nasal seal.

[0249] 5.3.1.3 Nasal Pillows

[0250] Figure 3EE And 3BB Another patient interface 3000 including a seal-forming structure 3100 according to examples of the present technology is shown. In these examples, the seal-forming structure of the non-invasive patient interface 3000 includes a pair of nasal puffs 7100, which can alternatively be referred to as nasal pillows, each nasal puff or pillow 7100 being structured and arranged to form a seal with a respective nare of the patient's nose.

[0251] The nasal pillows 7100 according to forms of the present technology include a protrusion 7120 structured and arranged to be inserted or partially inserted into a respective one of the patient's nare in use. Each nasal pillow 7100 has formed therein an opening 7140 configured to allow a continuous flow of air therethrough such that, when the patient interface 3000 is worn, air flows into the patient's nare.

[0252] In certain forms of the technology, the protrusions 7120 are each configured to extend partially into a respective one of the patient’s nares. For example, each protrusion 7120 is constructed and arranged to seal with an inner periphery of the respective naris in use. As such, each protrusion 7120 is of a height that is less than such protrusions 7120 on conventional nasal pillow patient interfaces. An edge of each protrusion 7120 forming the opening 7140 is configured to seal against an inner periphery of the respective naris.

[0253] Each protrusion 7120 can be formed in the shape of a frusto-cone.

[0254] In use, the protrusions 7120 are positioned in contact with the outer periphery of the patient’s nares and can be used to position the patient interface 3000 in the intended position on the patient’s face and to hold the patient interface 3000 in that position during use.

[0255] The protrusions 7120 can be formed such that the openings 7140 are angled in a manner that is consistent with the angle of the patient’s nares. That is, the angle of the edge of each protrusion 7120 forming the opening 7140 has an orientation that is aligned or substantially aligned with a plane formed by the inner periphery of the respective naris.

[0256] 5.3.1.3.1 Seal-forming structure and base portion

[0257] In the example patient interface 3000 shown in Figure 3EE and 3FF , the nasal pillows 7100 include a base portion 7160 to which the protrusions 7120 are provided. The protrusions extend out of the rear side of the base portion 7160. The base portion 7160 and the protrusions 7120 can be formed from the same material and, in certain forms, they are formed as a single piece, e.g. they are integrally moulded.

[0258] As shown in Figure 3EE and 3FF , in some forms of the technology, the base portion 7160 includes lateral extensions 7180 that extend outwardly from the base of each protrusion 7120 on the lateral sides of the protrusions 7120. The lateral extensions 7180 are of a size and orientation such that, when the patient interface 3000 is worn, the lateral extensions each seal against a lateral or inferior portion of one of the patient’s nasal wings. This improves the quality of the seal and also stabilises the seal-forming structure in use, reducing the risk of the seal being compromised in use.

[0259] The base portion 7160 is formed with a generally positive curvature in the lateral direction. For example, the base portion 7160 can be generally U-shaped when viewed from the front side during use. The base can have a positive, negative or zero curvature in the anterior-posterior direction (i.e. the sagittal plane). The positive curvature of the base portion 7160 in the lateral direction presents the protrusions 7120 to the respective nostril, while the base portion 7160 between the protrusions 7120 is further positioned in the forward direction to avoid contact with the patient’s columella.

[0260] The base portion 7160 can be configured such that, in the absence of any force acting on the base portion 7160, the base portion 7160 has a certain amount of positive curvature in the lateral direction, such that when worn by a patient, the engagement of the base with the nose reduces the positive curvature of the base portion 7160. That is, the ‘natural’ or ‘rest’ curvature of the base portion 7160 is greater than the curvature of the base portion 7160 when worn. In examples where the base portion 7160 is formed of a resilient material or is configured to resiliently return to its original shape when not worn, when the patient interface is worn, the lateral portions of the base are forced inward against the patient’s nose. This helps to form a seal to the nose and stabilise the patient interface in the required position.

[0261] It will be appreciated that different patient interfaces can include base portions having different amounts of positive curvature in their ‘rest’ state in order to cater for patients with noses and / or faces of different sizes and / or shapes. For example, Figure 3EE The base portion 7160 shown in Figs. 16A and 16B has a greater positive curvature than Figure 3FF The base portion 7160 shown in Figs. 16A and 16B has a greater positive curvature than

[0262] 5.3.1.3.2 Plenum chamber

[0263] In the region where the seal is formed in use, the plenum chamber 3200 has a perimeter that is shaped to complement the surface contours of an average human face. In use, the border edges of the plenum chamber 3200 are positioned close to the adjacent surfaces of the face. Actual contact with the face is provided by the seal-forming structure 3100. The seal-forming structure 3100 can extend around the entire perimeter of the plenum chamber 3200 in use. In some forms, the plenum chamber 3200 and the seal-forming structure 3100 are formed from a single piece of homogenous material.

[0264] In certain forms of the technology, the plenum chamber 3200 is constructed from a transparent material, such as transparent polycarbonate. The use of a transparent material can reduce the prominence of the patient interface and help improve compliance with therapy. The use of a transparent material can assist a clinician to observe how the patient interface is positioned and functioning.

[0265] In certain forms of the present technology, the plenum chamber 3200 is constructed from a translucent material. The use of a translucent material can reduce the prominence of the patient interface and help improve compliance with therapy.

[0266] In certain forms of the present technology, the plenum chamber 3200 is formed from the same material as the seal-forming structure 3100. In Figure 3EE and 3FF In the form of the technology illustrated in Figs. 31A and 31B, the plenum chamber 3200 and the seal-forming structure 3100 are integrally formed.

[0267] One or more positioning and stabilising structure connectors 7500 can be provided to the plenum chamber 3200. The positioning and stabilising structure connectors 7500 are configured to connect to the positioning and stabilising structure 3300 in use. In one form, the positioning and stabilising structure connectors 7500 can comprise clips, buckles or any other connector capable of connecting to the positioning and stabilising structure 3300 or being connected to the positioning and stabilising structure by the positioning and stabilising structure, such as headgear straps.

[0268] In the form of the technology illustrated in Figs. 31A and 31B, the plenum chamber 3200 and the seal-forming structure 3100 are integrally formed. Figure 3EE and 3FF In the form of the technology illustrated in Figs. 31A and 31B, the plenum chamber 3200 and the seal-forming structure 3100 are integrally formed.

[0269] 5.3.1.3.3 Decoupling folds in the seal-forming structure / plenum chamber

[0270] In certain forms of the technology, a portion of the base portion 7160 of the seal-forming structure 3100 and / or a portion of the plenum chamber 3200 can form one or more folds 7220. For example, one or more folds 7220 can be provided in a portion of the base portion 7160 that is connected to and / or adjacent to the plenum chamber 3200. Alternatively, one or more folds 7220 can be provided in a portion of the plenum chamber 3200 that is connected to and / or adjacent to the base portion 7160. Alternatively, one or more folds 7220 can form a portion of the portion that is connected between the base portion 7160 and the plenum chamber 3200.

[0271] In the form of the technology illustrated in Figs. 31A and 31B, the plenum chamber 3200 and the seal-forming structure 3100 are integrally formed. Figure 3EE and 3FFIn the illustrated form of the technology, the patient interface 3000 includes a single fold 7220 between the base portion 7160 and the plenum chamber 3200. The base portion 7160 is connected to the plenum chamber 3200 along a region of generally elliptical or elongate shape that has a range that is less than the outer range of the base portion 7160. This means that the fold 7220 is a fold inward. In other forms, one or more folds can include a fold outward. In other forms, one or more folds can include at least one fold inward and at least one fold outward, for example in an accordion or bellows fashion.

[0272] In use, the patient interface 3000 can be donned by the patient by inserting the patient’s mouth and / or nasal passages into the plenum chamber 3200 and then securing the headgear 7100 to the base portion 7160. Figure 3EE and 3FF In the illustrated form of the technology, the fold 7220 extends around the entire perimeter of the base portion 7160. In other forms, one or more folds 7220 can extend only around a portion of the perimeter of the base portion 7160. That is, the perimeter of the base portion 7160 can include one or more portions with one or more folds 7220 and one or more portions without a fold.

[0273] The one or more folds 7220 can serve to decouple, in use, motion of the base portion 7160 from the plenum chamber 3200 at least in part. Additionally or alternatively, the one or more folds 7220 can enable the seal-forming structure 7100 to accommodate different facial geometries of different patients. Additionally or alternatively, the one or more folds 7220 can act like a spring, such that when the patient wearing the patient interface 3000 deforms and pushes the base portion 7160 towards the plenum chamber 3200, the one or more folds 7220 tend to push the base portion 7160 towards the patient’s face, thereby helping to maintain the seal-forming structure 3100 in sealing engagement with the patient’s face. Additionally or alternatively, the one or more folds 7220 can be configured to inflate or partially inflate when pressurized air enters the plenum chamber 3200 and / or the seal-forming structure 3100. This inflation can help to push the base portion 7160 towards the patient’s face, helping to maintain the seal-forming structure 3100 in sealing engagement with the patient’s face.

[0274] 5.3.2 Positioning and stabilising structure

[0275] The seal-forming structure 3100 of the patient interface 3000 of the present technology can be maintained, in use, in a sealed condition by the positioning and stabilising structure 3300.

[0276] In one form, the positioning and stabilising structure 3300 provides a retention force that is at least sufficient to overcome the effect of positive pressure in the plenum chamber 3200 to lift away from the face.

[0277] In one form, the positioning and stabilising structure 3300 provides a retention force to overcome the effects of gravity on the patient interface 3000.

[0278] In one form, the positioning and stabilising structure 3300 provides a retention force as a safety margin to overcome potential effects of disruptive forces on the patient interface 3000, such as from tube drag or accidental interference with the patient interface.

[0279] In one form of the present technology, the positioning and stabilising structure 3300 is configured to be consistent with being worn by a patient while sleeping. In one example, the positioning and stabilising structure 3300 has a small side or cross-sectional thickness to reduce the perceived or actual bulk of the apparatus. In one example, the positioning and stabilising structure 3300 comprises at least one strap that is rectangular in cross-section. In one example, the positioning and stabilising structure 3300 comprises at least one flat strap.

[0280] In one form of the present technology, there is provided a positioning and stabilising structure 3300 configured to be not too large and bulky to prevent a patient from lying in a supine sleeping position with the dorsal region of the patient's head on a pillow.

[0281] In one form of the present technology, there is provided a positioning and stabilising structure 3300 configured to be not too large and bulky to prevent a patient from lying in a side sleeping position with the lateral region of the patient's head on a pillow.

[0282] In one form of the present technology, the positioning and stabilising structure 3300 is provided with a decoupling portion between the front of the positioning and stabilising structure 3300 and the rear of the positioning and stabilising structure 3300. This decoupling portion does not resist compression and can be, for example, a flexible or soft strap. The decoupling portion is constructed and arranged so that when a patient lies with their head on a pillow, the presence of the decoupling portion prevents forces acting on the rear from being transmitted along the positioning and stabilising structure 3300 and disrupting the seal.

[0283] 5.3.2.1 Headgear straps

[0284] In one form of the present technology, the positioning and stabilising structure 3300 comprises a strap constructed from a laminate of a fabric patient contact layer, a foam inner layer, and a fabric outer layer. In one form, the foam is porous to enable moisture (e.g. sweat) to pass through the strap. In one form, the fabric outer layer comprises loop material for partial engagement with hook material.

[0285] In certain forms of the present technology, the positioning and stabilising structure 3300 comprises a strap that is extendable, for example elastically extendable. For example, the strap can be constructed to be in tension when in use and to direct forces to cause the seal-forming structure to be in sealing contact with a portion of the patient's face. In one example, the strap can be constructed as a tie.

[0286] In one form of the technology, the positioning and stabilising structure comprises a first tie, the first tie being constructed and arranged so that, in use, at least a portion of a lower edge of the first tie passes over the superior ear base point of the patient's head and covers a portion of the parietal bone without covering the occipital bone.

[0287] In certain forms of the technology, the positioning and stabilising structure 3300 comprises a strap that is flexible and, for example, non-rigid. An advantage of this aspect is that the strap is more comfortable for the patient to lie on while sleeping.

[0288] In certain forms of the technology, the positioning and stabilising structure 3300 comprises a strap that is constructed to be breathable to allow moisture to be transported through the strap,

[0289] In certain forms of the technology, a system is provided that includes more than one positioning and stabilising structure 3300, each configured to provide a holding force to correspond to a different size and / or shape range. For example, the system can include one form of positioning and stabilising structure 3300 that is suitable for large sized heads but not small sized heads, and another form of positioning and stabilising structure that is suitable for small sized heads but not large sized heads.

[0290] 5.3.2.2 Gas delivery tubes

[0291] In some forms of the technology, the positioning and stabilising structure 3300 includes one or more conduits in the form of gas delivery tubes that deliver pressurised air received from the air circuit 4170 from the RPT device to the airways of the patient, for example, through the plenum chamber 3200 and the seal-forming structure 3100. In these forms, the positioning and stabilising structure 3300 can be referred to as a conduit headgear, and in addition to delivering pressurised air to the airways, is used to position and stabilise the seal-forming structure 3100 of the patient interface to the appropriate portions of the patient's face. In this specification, unless the context clearly indicates otherwise, the terms "tube" and "conduit" are to be understood as interchangeable. In these forms, the conduit headgear contacts at least one region of the patient's head superior to the superior ear base point of the patient's head. As shown in Figure 2D

[0292] In one example, the tube can be substantially cylindrical. However, in other examples, the tube can be formed with various cross-sectional shapes. For example, a substantially D-shaped cross-sectional profile can be used; the flat side of this profile can contact the patient's face while being worn and can be more comfortable than a semi-circular profile.

[0293] ​In some forms of the technology, the conduit headgear includes a pair of tubes that convey pressurized air from a downstream end of the air circuit to the seal-forming structure. By way of example, the tubes can be connected at their upper ends to a crown connector that has a connection port to fluidly engage with the downstream end of the air circuit and form an integral part of the positioning and stabilizing structure of the patient interface. The tubes can be disconnected, for example for cleaning or storage.

[0294] In some forms of the technology, the conduit headgear includes left and right tubes that fluidly engage or are otherwise connected at their lower ends to the patient interface 3000 so as to convey pressurized air to the seal-forming structure. The connection port to engage with the downstream end of the air circuit 4170 is provided to an upper portion of the conduit headgear where the two arms of the tubes meet. In this example, the conduit headgear is substantially an integral structure.

[0295] In certain examples, the connection port is generally located at the top of the patient's head when the conduit headgear is worn. However, it will be appreciated that the connection port can be provided in different locations depending on the shape of the conduit headgear. For example, rather than meeting across the top of the patient's head, the tubes can be arranged to meet further back towards the rear of the patient's head. This would bring the connection port closer to a portion of the rear of the patient's head rather than the top of the head. Alternatively, the connection port can be provided elsewhere, for example provided to one of the two tubes rather than where they meet.

[0296] In certain examples of the technology, the conduit headgear is formed from a suitably resilient material that provides sufficient stabilizing force to correctly position the patient interface in a sealing arrangement on the patient's head. In certain other examples, the positioning and stabilizing structure includes a mechanism for connecting a headgear strap or other stabilizing component to the headgear tubes. The headgear strap can supplement the stabilizing force provided by the conduit headgear and assist in correctly positioning the patient interface in a sealing arrangement on the patient's head.

[0297] In these examples, the headgear strap can be connected directly or indirectly to the headgear tubes. In the case of one form of the patient interface, a tab configured to connect to a rear strap protrudes from the tube in a generally rearward direction. There is a slot in the tab to receive an end of the strap.

[0298] The rear strap can be secured to itself, for example using hook and loop fastening material, after being passed through the slot in the tab. The rear strap can be adjustable to fit around different head sizes. In some forms of the technology, more than one tab can be provided to the tube in order to provide a range of selectable placements of the rear strap for the patient. This helps to ensure that the sealing force is applied appropriately to the face.

[0299] In some examples, the tubes of the conduit headgear can be formed from a textile, spacer fabric, and / or a foam material. The portions of the tubes that contact the patient can be formed from a textile or fabric to make the patient more comfortable. In some examples, the tubes can be formed from a semi-rigid material, such as an elastomeric material, for example, silicone. In these examples, the tubes can include a thin sleeve of fabric or textile wrapped around them. The sleeve can be more comfortable against the patient's face than the tubes without any covering layer.

[0300] In some examples, the tubes of the conduit headgear can have a natural pre-shaped shape that conforms to the overall shape of a patient's head. In some examples, the tubes can have at least some ability to deform if force is applied to the tubes or to conform to a patient's head. For example, the tubes can generally be arcuate or curved in shape that approximates the head contour between the top of the patient's head and the nasal or oral region.

[0301] The conduit headgear can be described as inflatable because it can contain and pass air through the tubes of the conduit headgear in order to deliver pressurized air from the air circuit 4170 to the patient's airways. It can be appreciated that an inflatable conduit headgear does not require that all of its components are inflatable. For example, when the positioning and stabilizing structure includes a headgear tube and a posterior strap, the headgear tube is inflatable while the posterior strap is not.

[0302] 5.3.3 Vent

[0303] In one form, the patient interface 3000 includes a vent 3400 constructed and arranged to allow washout of exhaled gases, such as carbon dioxide.

[0304] In certain forms, the vent 3400 is configured to allow a continuous vent flow from an interior of the plenum chamber 3200 to ambient, while the pressure within the plenum chamber is positive relative to ambient. The vent 3400 is configured so that the vent flow has a magnitude sufficient to reduce rebreathing of exhaled C02 by the patient, while maintaining the therapeutic pressure in the plenum chamber in use.

[0305] One form of a vent 3400 according to the present technology includes a plurality of holes, for example, about 20 to about 80 holes, or about 40 to about 60 holes, or about 45 to about 55 holes.

[0306] The vent 3400 can be located in the plenum chamber 3200. Alternatively, the vent 3400 is located in a decoupling structure, such as a swivel.

[0307] The vent 3400 provided to the plenum chamber 3200 can include a plurality of openings 3402. The openings 3402 can be arranged in two groups that are symmetric about a centreline of the plenum chamber 3200. The plurality of openings 3402 can reduce noise and diffuse vent flow concentration.

[0308] The opening 3402 can be positioned close enough to the centerline of the inflation chamber 3200 so that it is not obstructed when the patient is sleeping on their side. To avoid weakening the chassis in a relatively narrow section, the opening 3402 can be spaced apart from the centerline.

[0309] Opening 3402 can have a circular profile.

[0310] exist Figure 3EE and 3FF In the example of the patient interface shown, the airway 3400 may be located on the front side of the inflation chamber 3200. For example, the inflation chamber 3200 may include an opening 7300 on its front side, configured to receive the airway 3400 in use. The airway 3400 may be configured as a ventilation module that can be removed and reinserted into the opening 7300, for example, to clean and / or replace the airway 3400.

[0311] 5.3.4 Decoupling Structure

[0312] In one embodiment, the patient interface 3000 includes at least one decoupling structure 3500, such as a swivel or ball joint. The decoupling structure 3500 may be in the form of a bend. The decoupling structure 3500 may have a swivel connected to an air circuit 4170 and a patient interface connector connected to the patient interface 3000. The patient interface connector may allow the tube of the decoupling structure 3500 to rotate relative to the patient interface 3000. The decoupling structure 3500 may also include a vent 3400. The vent 3400 of the decoupling structure 3500 may include at least one opening passing through a portion of the tube and / or through a portion of the patient interface connector.

[0313] In one form of this technology, the decoupling structure can be connected to the opening 7300 on the front side of the inflation chamber 3200 during use.

[0314] In another form of the technology, the decoupling structure can be connected to a connection port 3600 during use. The connection port is included in or disposed in one or more gas delivery tubes, which are included as part of the positioning and stabilizing structure 3300 and are positioned in use in a region adjacent to the patient's head above the upper ear base point.

[0315] 5.3.5 Connection Port

[0316] Connection port 3600 allows connection to air circuit 4170.

[0317] In certain forms of the technology, the connection port 3600 can be an opening 7300 on the front side of the plenum chamber 3200. The connection port 3600 can be configured to connect to, and / or be decoupled from, the air circuit 4170, e.g. a elbow.

[0318] In alternative forms of the technology, e.g. those incorporating the patient interface 3000, as shown in Figure 3EE and 3FF The patient interface includes a connection port, the connection port being included in, or provided to, one or more gas delivery tubes, the one or more gas delivery tubes including being part of the positioning and stabilising structure 3300. In such examples, the connection port is positionable, in use, adjacent to a region of the patient's head superior to the otobasion superior of the patient's head. In these examples, air is delivered to the seal-forming structure 3100 via the connection port and the gas delivery tubes that are part of the positioning and stabilising structure 3300.

[0319] 5.3.6 Ports

[0320] In one form of the technology, the patient interface 3000 includes one or more ports that allow access to the volume within the plenum chamber 3200. In one form, this enables a clinician to supply supplemental oxygen. In one form, this enables direct measurement of a property of the gas within the plenum chamber 3200, such as pressure.

[0321] 5.4 RPT devices

[0322] An RPT device 4000 according to an aspect of the technology includes mechanical, pneumatic, and / or electrical components, and is configured to execute one or more algorithms. The RPT device 4000 can be configured to generate a flow of air for delivery to the airways of a patient, e.g. for treating one or more of the respiratory conditions described elsewhere in this document.

[0323] In one form, the RPT device 4000 is constructed and arranged to be capable of delivering a flow of air in the range -20 L / min to +150 L / min, while maintaining a positive pressure of at least 6 cmH20, or at least 10 cmH20, or at least 20 cmH20.

[0324] The RPT device can have an outer casing 4010, which is constructed in two parts: an upper part 4012 and a lower part 4014. In addition, the outer casing 4010 can include one or more panels 4015. The RPT device 4000 includes a chassis 4016, which supports one or more of the internal components of the RPT device 4000. The RPT device 4000 can include a handle 4018.

[0325] The pneumatic path of the RPT device 4000 can comprise one or more air paths items, for example, an inlet air filter 4112, an inlet silencer 4122, a pressure generator 4140 capable of supplying air at positive pressure (e.g. a blower 4142), an outlet silencer 4124, and one or more transducers 4270 such as pressure and flow sensors.

[0326] One or more air path items can be provided within a detachable separate structure, which will be referred to as a pneumatic block 4020. The pneumatic block 4020 can be provided within the outer housing 4010. In one form, the pneumatic block 4020 is supported by, or forms part of, the chassis 4016.

[0327] The RPT device 4000 can have a power supply 4210, one or more input devices 4220, a central controller, a therapy device controller, a pressure generator 4140, one or more protection circuits, a memory, transducers 4270, a data communication interface, and one or more output devices. The electrical components 4200 can be mounted on a single printed circuit board assembly (PCBA) 4202. In an alternative form, the RPT device 4000 can include more than one PCBA 4202.

[0328] 5.4.1 RPT device mechanical and pneumatic components

[0329] The RPT device can include one or more of the following components in an integral unit. In an alternative form, one or more of the following components can be provided as separate units.

[0330] 5.4.1.1 Air filter

[0331] An RPT device according to one form of the present technology can include one air filter 4110, or a plurality of air filters 4110.

[0332] In one form, the inlet air filter 4112 is positioned at the start of the pneumatic path upstream of the pressure generator 4140.

[0333] In one form, an outlet air filter 4114, for example an anti-bacterial filter, is positioned between the outlet of the pneumatic block 4020 and the patient interface 3000.

[0334] 5.4.1.2 Silencer

[0335] An RPT device according to one form of the present technology can include one silencer 4120, or a plurality of silencers 4120.

[0336] In one form of the present technology, the inlet silencer 4122 is positioned in the pneumatic path upstream of the pressure generator 4140.

[0337] In one form of the present technology, an outlet muffler 4124 is positioned in the pneumatic path between the pressure generator 4140 and the patient interface 3000.

[0338] 5.4.1.3 Pressure generator

[0339] In one form of the present technology, the pressure generator 4140 for generating a flow of air, or air supply, at positive pressure is a controllable blower 4142. For example, the blower 4142 can include a brushless DC motor 4144 with one or more impellers encased in a volute. The blower is capable of delivering an air supply, for example, at rates up to about 120 litres / minute, and at positive pressures in the range of about 4 cmH20 to about 20 cmH20 or other forms up to about 30 cmH20. The blower can be as described in any one of the following patents or patent applications, which are incorporated herein by reference in their entirety: U.S. Patent No. 7,866,944; U.S. Patent No. 8,638,014; U.S. Patent No. 8,636,479; and PCT Patent Application No. WO 2013 / 020167.

[0340] The pressure generator 4140 is under the control of the therapy device controller.

[0341] In other words, the pressure generator 4140 can be a piston-driven pump, a pressure regulator connected to a high pressure source (e.g. a compressed air reservoir), or a bellows.

[0342] 5.4.1.4 Transducer

[0343] The transducer can be internal to the RPT device, or external to the RPT device. An external transducer can be positioned on or form part of, for example, the air circuit, e.g. the patient interface. The external transducer can be in the form of a non-contact sensor, such as a Doppler radar motion sensor that transmits or transmits data to the RPT device.

[0344] In one form of the present technology, one or more transducers 4270 can be positioned upstream and / or downstream of the pressure generator 4140. The one or more transducers 4270 can be constructed and arranged to generate a signal representative of a characteristic of the flow of air, such as flow rate, pressure or temperature, at that point in the pneumatic path.

[0345] In one form of the present technology, one or more transducers 4270 can be positioned proximally of the patient interface 3000.

[0346] In one form, the signal from the transducer 4270 can be filtered, such as by low pass filtering, high pass filtering, or band pass filtering.

[0347] 5.4.1.4.1 Flow rate sensor

[0348] Flow sensors according to the present technology can be based on differential pressure transducers, such as the SDP600 series differential pressure transducers from SENSIRION.

[0349] In one form, signals indicative of flow rate from the flow sensor are received by the central controller.

[0350] 5.4.1.4.2 Pressure sensor

[0351] Pressure sensors according to the present technology are provided in fluid communication with the pneumatic path. An example of a suitable pressure sensor is a transducer from the HONEYWELL ASDX series. An alternative suitable pressure sensor is a transducer from the NPA series from GENERAL ELECTRIC.

[0352] In one form, signals from the pressure sensor are received by the central controller.

[0353] 5.4.1.4.3 Motor speed transducer

[0354] In one form of the present technology, a motor speed transducer is used to determine the rotational speed of the motor 4144 and / or the blower 4142. Motor speed signals from the motor speed transducer can be provided to the therapy device controller. The motor speed transducer can be, for example, a tachometer, such as a Hall effect sensor.

[0355] 5.4.1.5 Anti-overflow back valve

[0356] In one form of the present technology, an anti-overflow back valve 4160 is positioned between the humidifier 5000 and the pneumatic block 4020. The anti-overflow back valve is constructed and arranged to reduce the risk of water flowing upstream from the humidifier 5000 to, for example, the motor 4144.

[0357] 5.4.2 RPT device electrical components

[0358] 5.4.2.1 Power supply

[0359] The power supply 4210 can be positioned inside or outside the external housing 4010 of the RPT device 4000.

[0360] In one form of the present technology, the power supply 4210 provides power to the RPT device 4000 only. In another form of the present technology, the power supply 4210 provides power to both the RPT device 4000 and the humidifier 5000.

[0361] 5.4.2.2 Input device

[0362] In one form of the technology, the RPT device 4000 includes one or more input devices 4220 in the form of buttons, switches or dials to allow a person to interact with the device. The buttons, switches or dials can be physical devices or software devices accessed via a touch screen. In one form, the buttons, switches or dials can be physically connected to the external housing 4010, or in another form, can be in wireless communication with a receiver that is in electrical connection with the central controller.

[0363] In one form, the input devices 4220 can be constructed or arranged to allow a person to select values and / or menu options.

[0364] 5.4.2.3 Central Controller

[0365] In one form of the technology, the central controller is one or more processors adapted to control the RPT device 4000.

[0366] Suitable processors can include x86 Intel processors, ARM Cortex-based processors from - processors based on the M-Processors from ST MICROELECTRONICS, such as the STM32 series of microcontrollers. In certain optional forms of the technology, 32-bit RISC CPUs such as the STR9 series of microcontrollers from STMicroelectronics, or 16-bit RISC CPUs such as the processors of the MSP430 series of microcontrollers manufactured by Texas Instruments can be equally suitable.

[0367] In one form of the technology, the central controller is a dedicated electronic circuit.

[0368] In one form, the central controller is an application specific integrated circuit. In another form, the central controller comprises discrete electronic components.

[0369] The central controller can be configured to receive input signals from one or more transducers 4270, one or more input devices 4220, and the humidifier 5000.

[0370] The central controller can be configured to provide output signals to one or more of the output devices, the therapy device controller, the data communication interface, and the humidifier 5000.

[0371] In some forms of the technology, the central controller is configured to implement one or more methods described herein, such as one or more algorithms expressed as computer programs stored in a non-transitory computer readable storage medium (e.g. memory). In some forms of the technology, the central controller can be integrated with the RPT device 4000. However, in some forms of the technology, some methods can be performed by a remotely located device. For example, a remotely located device can determine a control setting value for a ventilator or detect a respiratory related event by analysing stored data such as from any of the sensors described herein.

[0372] 5.5 Air circuit

[0373] An air circuit 4170 according to an aspect of the technology is a conduit or tube which, in use, is constructed and arranged to allow a flow of air to travel between two components, such as the RPT device 4000 and the patient interface 3000.

[0374] In particular, the air circuit 4170 can be in fluid connection with the outlet of the pneumatic block 4020 and the patient interface. The air circuit can be referred to as an air delivery tube. In some cases, there can be separate limbs for inhalation and exhalation circuits. In other cases, a single limb is used.

[0375] In some forms, the air circuit 4170 can include one or more heating elements configured to heat air in the air circuit, for example to maintain or raise the temperature of the air. The heating elements can be in the form of a heating wire circuit, and can include one or more transducers, such as temperature sensors. In one form, the heating wire circuit can be helically wound around the axis of the air circuit 4170. The heating elements can be in communication with a controller, such as the central controller. One example of an air circuit 4170 including a heating wire circuit is described in US Patent 8,733,349, which is incorporated herein in its entirety by this reference.

[0376] 5.5.1 Oxygen delivery

[0377] In one form of the technology, supplemental oxygen 4180 is delivered to one or more points in the pneumatic path (such as upstream of the pneumatic block 4020), the air circuit 4170 and / or the patient interface 3000.

[0378] 5.6 Humidifier

[0379] 5.6.1 Humidifier overview

[0380] In one form of the technology, a humidifier 5000 (e.g. as shown in Figure 5AThe humidifier 5000 can include a humidifier reservoir 5110, a humidifier inlet 5002 for receiving an air flow, and a humidifier outlet 5004 for delivering a humidified air flow. In some forms, as shown in Figs. 5A and 5B, the humidifier reservoir 5110 can be configured to receive a water reservoir 5110 and a wick 5120. The humidifier 5000 can also include a humidifier base 5006 which can be adapted to receive the humidifier reservoir 5110 and which includes a heating element 5240.

[0381] The humidifier 5000 can include a humidifier reservoir 5110, a humidifier inlet 5002 for receiving an air flow, and a humidifier outlet 5004 for delivering a humidified air flow. In some forms, as shown in Figs. 5A and 5B, the humidifier reservoir 5110 can be configured to receive a water reservoir 5110 and a wick 5120. The humidifier 5000 can also include a humidifier base 5006 which can be adapted to receive the humidifier reservoir 5110 and which includes a heating element 5240. Figure 5A Figure 5B The humidifier 5000 can include a humidifier reservoir 5110, a humidifier inlet 5002 for receiving an air flow, and a humidifier outlet 5004 for delivering a humidified air flow. In some forms, as shown in Figs. 5A and 5B, the humidifier reservoir 5110 can be configured to receive a water reservoir 5110 and a wick 5120. The humidifier 5000 can also include a humidifier base 5006 which can be adapted to receive the humidifier reservoir 5110 and which includes a heating element 5240.

[0382] 5.6.2 Humidifier components

[0383] 5.6.2.1 Water reservoir

[0384] According to one arrangement, the humidifier 5000 can include a water reservoir 5110 configured to hold or retain a volume of liquid (e.g. water) to be vaporised for humidifying an air flow. The water reservoir 5110 can be configured to hold a predetermined maximum water volume so as to provide sufficient humidification for a duration of at least a respiratory treatment session, such as a night of sleep. Typically, the reservoir 5110 is configured to hold a few hundred millilitres of water, for example, 300 millilitres (ml), 325 ml, 350 ml or 400 ml. In other forms, the humidifier 5000 can be configured to receive a supply of water from an external water source, such as a building's water supply system.

[0385] According to one aspect, the water reservoir 5110 is configured to add humidity to an air flow from the RPT device 4000 as the air flow travels therethrough. In one form, the water reservoir 5110 can be configured to facilitate the air flow to travel in a tortuous path through the reservoir 5110 while in contact with a volume of water therein.

[0386] According to one form, the reservoir 5110 can be removable from the humidifier 5000, for example, in a lateral direction as shown in Figs. 5A and 5B. Figure 5A Figure 5B According to one form, the reservoir 5110 can be removable from the humidifier 5000, for example, in a lateral direction as shown in Figs. 5A and 5B.

[0387] The reservoir 5110 can also be configured to prevent the flow of liquid therefrom, such as through any orifices and / or between sub-components thereof, such as when the reservoir 5110 is displaced and / or rotated from its normal operating orientation. As the air flow to be humidified by the humidifier 5000 is typically pressurised, the reservoir 5110 can also be configured to avoid loss of pneumatic pressure through leaks and / or flow impedance. ​​

[0388] 5.6.2.2 Conduction portion

[0389] According to one arrangement, the reservoir 5110 includes a conduction portion 5120 configured to allow efficient transfer of heat from the heating element 5240 to the volume of liquid in the reservoir 5110. In one form, the conduction portion 5120 can be arranged as a plate, although other shapes can be equally suitable. All or a portion of the conduction portion 5120 can be made of a thermally conductive material, such as aluminum (e.g., approximately 2 mm in thickness, such as 1 mm, 1.5 mm, 2.5 mm, or 3 mm), another thermally conductive metal, or some plastics. In some cases, a material with lower conductivity can be used with an appropriate geometry to achieve suitable thermal conduction.

[0390] 5.6.2.3 Humidifier reservoir dock

[0391] In one form, the humidifier 5000 can include a humidifier reservoir dock 5130 (as shown in FIG. 51), which is configured to receive the humidifier reservoir 5110. In some arrangements, the humidifier reservoir dock 5130 can include a locking structure, such as a locking bar 5135 configured to hold the reservoir 5110 in the humidifier reservoir dock 5130. Figure 5B

[0392] 5.6.2.4 Water level indicator

[0393] The humidifier reservoir 5110 can include a water level indicator 5150, as shown in FIG. 52. In some forms, the water level indicator 5150 can provide one or more indications to a user (such as the patient 1000 or a caregiver) regarding the amount of water volume in the humidifier reservoir 5110. The one or more indications provided by the water level indicator 5150 can include an indication of a maximum predetermined volume of water, any portion thereof, such as 25%, 50%, 75%, or a volume such as 200 ml, 300 ml, or 400 ml. Figures 5A-5B

[0394] 5.6.2.5 Heating element

[0395] In some cases, a heating element 5240 can be provided to the humidifier 5000 to input heat to one or more of the volume of water in the humidifier reservoir 5110 and / or to the flow of air. The heating element 5240 can include a heat-emitting component, such as a resistive electrical heating track. One suitable example of a heating element 5240 is a layered heating element, such as that described in PCT Patent Application Publication No. WO 2012 / 171072, which is incorporated herein by reference in its entirety.

[0396] ​​In some forms, the heating element 5240 can be provided in the humidifier base 5006, where it can provide heat to the humidifier reservoir 5110 primarily by conduction, as shown in Figure 5B

[0397] 5.7 Breathing Waveform

[0398] Figure 6 A model human's typical breathing waveform is shown. The horizontal axis is time, and the vertical axis is respiratory flow rate. While the parameter values can vary, a typical breath can have the following approximate values: tidal volume Vt 0.5 L, inspiration time Ti 1.6 s, peak inspiratory flow rate Qpeak 0.4 L / s, expiration time Te 2.4 s, peak expiratory flow rate Qpeak-0.5 L / s. The total duration of the breath Ttot is approximately 4 s. Humans typically breathe at a rate of approximately 15 breaths per minute (BPM), with a ventilation of approximately 7.5 L / min. The typical duty cycle, the ratio of Ti to Ttot, is approximately 40%.

[0399] 5.8 Glossary

[0400] To achieve the objects of the present technology, one or more of the following definitions can be applied in certain forms of the present technology. In other forms of the present technology, alternative definitions can be applied.

[0401] 5.8.1 General

[0402] Air: In certain forms of the present technology, air can be taken to mean atmospheric air, and in other forms of the present technology, air can be taken to mean some other combination of breathable gases, such as atmospheric air enriched with oxygen.

[0403] Ambience: In certain forms of the present technology, the term ambience can have the following meanings (i) the exterior of the therapy system or patient, and (ii) the immediate surroundings of the therapy system or patient.

[0404] For example, the ambient humidity with respect to a humidifier can be the humidity of the air immediately surrounding the humidifier, such as the humidity in the room in which the patient is sleeping. This ambient humidity can be different from the humidity outside the room in which the patient is sleeping.

[0405] In another example, the ambient pressure can be the pressure immediately surrounding the body or outside the body.

[0406] In certain forms, the ambient (e.g. acoustic) noise can be taken to be the background noise level in the room in which the patient is located, other than noise generated, for example, by the RPT device or from the mask or patient interface. The ambient noise can be generated by sound sources outside the room.

[0407] ​Auto-Positive Airway Pressure (APAP) therapy: CPAP therapy in which the therapy pressure is automatically adjustable between a minimum and a maximum, e.g. different for each breath, depending on whether or not there are indications of SBD events.

[0408] Continuous Positive Airway Pressure (CPAP) therapy: respiratory pressure therapy in which the therapy pressure can be approximately constant throughout the patient's respiratory cycle. In some forms, the pressure at the entrance to the airways will be slightly higher during exhalation and slightly lower during inhalation. In some forms, the pressure will vary between different respiratory cycles of the patient, e.g. increase in response to detection of indications of partial airway obstruction, and decrease in the absence of indications of partial airway obstruction.

[0409] Flow: volume (or mass) of air delivered per unit of time. Flow can refer to instantaneous quantities. In some contexts, reference to flow will be reference to a scalar quantity, i.e. a quantity with only a magnitude. In other contexts, reference to flow will be reference to a vector quantity, i.e. a quantity with both magnitude and direction. Flow can be given the symbol Q. 'Flow' is sometimes simply abbreviated to 'flow' or 'air flow'.

[0410] In the example of a patient breathing, the flow can be nominally positive for the inhalation portion of the patient's respiratory cycle, and thus negative for the exhalation portion of the patient's respiratory cycle. The total flow Qt is the flow of air leaving the RPT device. The ventilation flow Qv is the flow of air leaving the vent to allow flushing of exhaled gases. The leak flow Ql is the flow of leaks from the patient interface system or elsewhere. The respiratory flow Qr is the flow of air received into the patient's respiratory system.

[0411] Humidifier: The term humidifier will be taken to mean a humidification apparatus constructed and arranged or configured with a physical structure capable of providing a therapeutically beneficial amount of water (H20) vapour to an air flow to improve a patient's medical respiratory condition.

[0412] Leak: The word leak will be taken to mean an unwanted flow of air. In one example, a leak can occur due to an imperfect seal between a mask and a patient's face. In another example, a leak can occur in a swivel elbow to ambient.

[0413] Noise, conducted (acoustic): Conducted noise in this document refers to noise delivered to the patient through the pneumatic path, such as the air circuit and patient interface and the air therein. In one form, conducted noise can be quantified by measuring the sound pressure level at the end of the air circuit.

[0414] Noise, Radiated (acoustic): Radiated noise in this document refers to noise that is carried by the surrounding air to the patient. In one form, radiated noise can be quantified by measuring the sound power / pressure level of the object in question according to ISO 3744.

[0415] Noise, Ventilation (acoustic): Ventilation noise in this document refers to noise generated by the flow of air through any vent, such as a vent of a patient interface.

[0416] Patient: A human, whether or not they suffer from a respiratory disorder.

[0417] Pressure: Force per unit area. Pressure can be expressed in units ranging from cmH20, g-f / cm 2 , to hundred Pascals. 1 cmH20 is equivalent to 1 g-f / cm 2 and is approximately 0.98 hundred Pascals. In this specification, pressure is given in units of cmH20 unless otherwise stated.

[0418] Pressure in a patient interface is given the symbol Pm, while therapy pressure is given the symbol Pt, which represents the target value achieved by the mask pressure Pm at the current instant in time.

[0419] Respiratory Pressure Therapy (RPT): The application of a supply of air at a therapy pressure that is typically positive relative to atmosphere to the entrance of the airways.

[0420] Respirator: A mechanical device that provides pressure support to a patient to perform some or all of the work of breathing.

[0421] 5.8.1.1 Materials

[0422] Silicone or Silicone Elastomer: A synthetic rubber. In this specification, reference to silicone refers to Liquid Silicone Rubber (LSR) or Compression Molded Silicone Rubber (CMSR). One form of commercially available LSR is SILASTIC (including the range of products sold under this trademark) manufactured by Dow Corning. Another manufacturer of LSR is Wacker. Unless otherwise specified to the contrary, an exemplary form of LSR has a Shore A (or Type A) indentation hardness in the range of about 35 to about 45 as measured using ASTM D2240. (Year? Needed?)

[0423] Polycarbonate: A transparent thermoplastic polymer of bisphenol-A carbonate.

[0424] 5.8.1.2 Mechanical Properties

[0425] Resilience: The ability of a material to absorb energy when elastically deformed and to release the energy upon unloading.

[0426] Elastic: will release substantially all of the energy upon unloading. Includes, for example, certain silicones and thermoplastic elastomers.

[0427] Hardness: the ability of a material itself to resist deformation (e.g. described by Young’s modulus or the indentation hardness scale measured on a standardised sample size).

[0428] • ‘Soft’ materials can include silicone or thermoplastic elastomers (TPE) and can deform easily, for example under finger pressure.

[0429] • ‘Hard’ materials can include polycarbonate, polypropylene, steel or aluminium and can not deform easily, for example under finger pressure.

[0430] Stiffness (or rigidity) of a structure or component: the ability of a structure or component to resist deformation in response to an applied load. The load can be a force or a moment, for example compression, tension, bending or torsion. A structure or component can provide different resistance in different directions.

[0431] Soft structure or component: a structure or component that will change shape (e.g. bend) when caused to support its own weight for a relatively short period of time, for example within 1 second.

[0432] Rigid structure or component: a structure or component that does not substantially change shape when subjected to loads typically encountered in use. An example of such use can be the setting and maintaining of a patient interface in a sealed relation to an entrance to a patient’s airways under pressures of around 20 to 30 cmH20.

[0433] As an example, an I-beam can comprise different bending stiffness (resistance to bending loads) in a first direction compared to a second, orthogonal direction. In another example, a structure or component can be soft in a first direction and stiff in a second direction.

[0434] 5.8.2 Breathing cycle

[0435] Apnoea: according to some definitions, an apnoea is considered to occur when the flow drops below a predetermined threshold for a duration of time, for example 10 seconds. An obstructive apnoea is considered to occur when some obstruction of the airways does not allow air flow, even with effort from the patient. A central apnoea is considered to occur when a pause in breathing is detected despite the airways being patent, due to a reduction or absence of respiratory effort. A mixed apnoea is considered to occur when a reduction or absence of respiratory effort coincides with an obstructed airway.

[0436] Breathing rate: the rate of a patient’s spontaneous breathing, which is typically measured in breaths per minute.

[0437] Duty cycle: the ratio of inspiration time, Ti, to total breath time, Ttot.

[0438] Effort (breathing): the work done by a spontaneously breathing subject in attempting to breathe.

[0439] Exhalation portion of the breath cycle: the period of time from the start of exhalation flow to the start of inhalation flow.

[0440] Flow limitation: a flow limitation will be considered to be a condition in the patient's breathing in which an increase in the patient's effort does not result in a corresponding increase in flow. A flow limitation that occurs during the inhalation portion of the breath cycle can be described as an inspiratory flow limitation. A flow limitation that occurs during the exhalation portion of the breath cycle can be described as an expiratory flow limitation.

[0441] Types of inspiratory waveform of flow limitation:

[0442] (i) flattened: with one rise, followed by a relatively flat portion, then a fall.

[0443] (ii) M-shaped: with two local peaks, one at the leading edge and one at the trailing edge, with a relatively flat portion between the two peaks.

[0444] (iii) chair-shaped: with a single local peak, the peak being at the leading edge, followed by a relatively flat portion.

[0445] (iv) reverse chair-shaped: with a relatively flat portion, followed by a single local peak, the peak being at the trailing edge.

[0446] Hypopnea: according to some definitions, a hypopnea will be considered to be a reduction in flow, rather than a cessation of flow. In one form, a hypopnea can be considered to occur when the flow reduces below a threshold value for a period of time. A central hypopnea is considered to occur when a hypopnea is detected as a result of a reduction in respiratory effort. In one form for adults, either of the following can be considered to be a hypopnea:

[0447] (i) a 30% reduction in patient breathing for at least 10 seconds plus an associated 4% desaturation; or

[0448] (ii) a reduction in patient breathing (but less than 50%) for at least 10 seconds with an associated at least 3% desaturation or arousal.

[0449] Hyperpnea: an increase in flow to above normal levels.

[0450] Inhalation portion of the breath cycle: the period of time from the start of inhalation flow to the start of exhalation flow is considered to be the inhalation portion of the breath cycle.

[0451] Open (airway): The degree to which the airway is open or the degree to which the airway is open. An open airway is open. Airway openness can be quantified, for example, with a value (1) for open, and a value zero (0) for closed (obstructed).

[0452] Positive end-expiratory pressure (PEEP): The pressure above atmospheric pressure that exists in the lungs at the end of expiration.

[0453] Peak flow (Qpeak): The maximum value of flow during the inspiratory portion of the respiratory flow waveform.

[0454] Respiratory flow, patient air flow, respiratory air flow (Qr): These synonymous terms can be understood to refer to the RPT device's estimate of respiratory flow, as opposed to "true respiratory flow" or "true respiratory flow", which is the actual respiratory flow experienced by the patient, typically expressed in litres per minute.

[0455] Tidal volume (Vt): The volume of air inhaled or exhaled during normal breathing when no extra effort is applied.

[0456] (Inspiratory) time (Ti): The duration of the inspiratory portion of the respiratory flow waveform.

[0457] (Expiratory) time (Te): The duration of the expiratory portion of the respiratory flow waveform.

[0458] (Overall) time (Ttot): The total duration between the start of one inspiratory portion of a respiratory flow waveform and the start of the subsequent inspiratory portion of a respiratory flow waveform.

[0459] Typical recent ventilation: A measure of the tendency of ventilation values, Vent, to cluster around recent values of ventilation, that is, a measure of the central tendency of recent values of ventilation.

[0460] Upper airway obstruction (UAO): Includes partial and total upper airway obstruction. This can be associated with a state of flow limitation in which flow only increases slightly, or even decreases, as the pressure difference across the upper airway increases (Starling resistance behaviour).

[0461] Ventilation (Vent): A measure of the rate of gas exchange by the patient's respiratory system. Measures of ventilation can include one or both of the inspiratory and expiratory flow rates (per unit time). When expressed as a volume per minute, this quantity is often referred to as "minute ventilation". Minute ventilation is sometimes simply given as a volume and understood to be volume per minute.

[0462] 5.8.3 Ventilation

[0463] Adaptive servo-ventilator (ASV): A servo-ventilator with a variable, rather than a fixed, target ventilation. The variable target ventilation can be learned from some characteristic of the patient, such as the patient's breathing characteristics.

[0464] Backup rate: A parameter of the ventilator that determines the minimum respiratory rate (usually in breaths per minute) that the ventilator will deliver to the patient if not triggered by a spontaneous breathing effort.

[0465] Cycle: The termination of the inspiratory phase of the ventilator. When the ventilator is delivering breaths to a spontaneously breathing patient, the ventilator is said to cycle to stop delivering breaths at the end of the inspiratory portion of the breathing cycle.

[0466] Exhalation positive airway pressure (EPAP): The base pressure to which a varying pressure is added within a breath to produce the desired mask pressure that the ventilator will attempt to achieve at a given time.

[0467] End-Exhalation Pressure (EEP): The desired mask pressure that the ventilator attempts to achieve at the end of the exhalation portion. If the pressure waveform template (P(t)) is zero at the end of exhalation, i.e., P(t) = 0 when t = 1, then the EEP is equal to the EPAP.

[0468] Inspiratory positive airway pressure (IPAP): The maximum desired mask pressure that the ventilator attempts to achieve during the inspiratory portion of a breath.

[0469] Pressure support: A number that indicates the increase in pressure during inspiration by the ventilator over the pressure during expiration by the ventilator, and usually means the difference between the maximum during inspiration and the base pressure (e.g., PS = IPAP - EPAP). In some cases, pressure support means the difference that the ventilator aims to achieve, not the difference that is actually achieved.

[0470] Servo-ventilator: A ventilator that measures the patient's ventilation, has a target ventilation, and adjusts the level of pressure support to bring the patient's ventilation to the target ventilation.

[0471] Spontaneous / timed (S / T): A mode of a ventilator or other device that attempts to detect the onset of a breath of a spontaneously breathing patient. However, if the device cannot detect a breath within a predetermined period of time, the device will automatically initiate the delivery of a breath.

[0472] Swing: A term synonymous with pressure support.

[0473] Triggered: When the ventilator delivers air of a breath to a spontaneously breathing patient, it is said to be triggered by the effort of the patient at the onset of the breathing portion of the breathing cycle.

[0474] Typical recent ventilation: A typical recent ventilation Vtyp is a value around which recent ventilation measurements tend to cluster over some predetermined time horizon. For example, a measure of the central tendency of ventilation measurements in the recent history can be a suitable value for the typical recent ventilation value.

[0475] 5.8.4 Anatomy

[0476] 5.8.4.1 Anatomy of the face

[0477] Ala: The outer, lateral wall or "wing" of each nostril (plural: alae)

[0478] Alar angle:

[0479] Alar crest: The most lateral point on the ala.

[0480] Alar curve (or alar crest) point: The point at the end of the curved base of each ala, found in the fold created by the junction of the ala with the cheek.

[0481] Auricle: The entire externally visible part of the ear.

[0482] (Nasal) skeletal framework: The skeletal framework of the nose includes the nasal bones, frontal process of the maxilla, and nasal part of the frontal bone.

[0483] (Nasal) cartilaginous framework: The cartilaginous framework of the nose includes the septum, lateral, greater, and lesser cartilages.

[0484] Columella: The skin strip separating the nostrils and extending from the tip of the nose to the upper lip.

[0485] Columellar angle: The included angle between a line drawn through the midpoint of the nostril and a line drawn perpendicular to the Frankfort horizontal (both lines intersect at the subnasal point).

[0486] Frankfort horizontal: A line extending from the lowest point of the orbital margin to the left ear canal. The canal is the deepest point in the notch superior to the tragus of the auricle.

[0487] Glabella: The most prominent point in the soft tissue, in the median sagittal plane of the forehead.

[0488] Lateral nasal cartilage: A cartilaginous plate that is essentially triangular in shape. Its superior border is attached to the nasal bone and frontal process of the maxilla, and its inferior border is connected to the greater alar cartilage.

[0489] Lip, lower (subnasale): The midpoint of the lower lip.

[0490] Lip, upper (supralabiale): The midpoint of the upper lip.

[0491] Alar cartilage: The cartilaginous plate located below the external cartilages of the nose. It curves around the front of the nostril. Its posterior end is connected to the frontal process of the maxilla by a tough fibrous membrane containing three or four small cartilages that make up the alar base.

[0492] Nares (nares): The approximately elliptical openings that form the entrance to the nasal cavity chambers. The singular form of nare is naris (nare). The nares are separated by the nasal septum.

[0493] Nasolabial sulcus or fold: The skin fold or groove that extends from the nose to the corner of the mouth on each side of the nose that separates the cheeks from the upper lip.

[0494] Nasolabial angle: The angle between the columella and the upper lip (which meets the subnasale point on the nasal septum).

[0495] Infralobular point: The lowest point of attachment of the helix to the skin of the face.

[0496] Supralobular point: The highest point of attachment of the helix to the skin of the face.

[0497] Nasal tip point: The most projecting point or tip of the nose that can be identified in a lateral view of the rest of the head.

[0498] Philtrum: The midline groove that extends from the lower border of the nasal septum to the lip superior in the region of the upper lip.

[0499] Prementale: The midpoint of the most forward part of the chin, located on soft tissue.

[0500] Nasal ridge: The midline prominence of the nose that extends from the sellion to the tip of the nose.

[0501] Midsagittal plane: The vertical plane that passes from the front (anterior) to the back (posterior) that divides the body into right and left halves.

[0502] Sellion: The most concave point, located on soft tissue, that overlies the region of the frontonasal suture.

[0503] Septal cartilage (nose): The nasal septal cartilage forms part of the septum and separates the anterior part of the nasal cavity chambers.

[0504] Posterosuperior limb: The point at the lower border of the alar base where the alar base meets the skin of the upper (superior) lip.

[0505] Subnasale: The point, located on soft tissue, where the columella meets the upper lip in the midsagittal plane.

[0506] Inframental point: The point on the midline of the lower lip that lies between the midpoint of the lower lip and the soft tissue prementale, where the greatest concavity is found.

[0507] 5.8.4.2 Anatomy of the skull

[0508] Frontal bone: The frontal bone includes a large vertical part (frontal squama) that corresponds to the area called the forehead.

[0509] Mandible: The mandible forms the lower jaw. The mental protuberance is the bony protuberance of the lower jaw that forms the chin.

[0510] Maxilla: The maxilla forms the upper jaw and lies above the mandible and below the eye sockets. The frontal process of the maxilla projects upward from the sides of the nose and forms part of the lateral boundary.

[0511] Nasal bone: The nasal bone is a small, oval-shaped bone that varies in size and form from individual to individual; it lies side by side in the middle and upper part of the face and forms the "bridge" of the nose with its junction.

[0512] Nasal root: The junction of the frontal bone and the two nasal bones, directly between the eyes and in the depressed area of the upper part of the bridge of the nose.

[0513] Occipital bone: The occipital bone is located at the back and lower part of the skull. It includes an oval-shaped hole (foramen magnum) through which the cranial cavity communicates with the spinal canal. The curved plate behind the foramen magnum is the squama occipitalis.

[0514] Orbit: The bony cavity in the skull that houses the eyeball.

[0515] Parietal bone: The parietal bone is the bone that, when joined together, forms the roof and the sides of the skull.

[0516] Temporal bone: The temporal bone is located at the bottom and on the sides of the skull and supports the part of the face known as the temple.

[0517] Zygomatic bone: The face includes two zygomatic bones, which are located in the upper and lateral parts of the face and form the prominence of the cheeks.

[0518] 5.8.4.3 Anatomy of the respiratory system

[0519] Diaphragm: A muscle sheet that extends across the bottom of the rib cage. The diaphragm separates the thoracic cavity, which contains the heart, lungs, and ribs, from the abdominal cavity. As the diaphragm contracts, the volume of the thoracic cavity increases and air is drawn into the lungs.

[0520] Larynx: The larynx or voice box houses the vocal cords and connects the lower part of the pharynx (hypopharynx) with the trachea.

[0521] Lungs: The respiratory organs of humans. The conducting region of the lungs includes the trachea, bronchi, bronchioles, and terminal bronchioles. The respiratory region includes respiratory bronchioles, alveolar ducts, and alveoli.

[0522] Nasal cavity: The nasal cavity (or nasal fossa) is the large air-filled space above and behind the nose in the middle of the face. The nasal cavity is divided into two parts by a vertical fin called the nasal septum. On the sides of the nasal cavity are three horizontal branches, which are called the nasal conchae (singular "concha") or turbinates. The front of the nasal cavity is the nose, while the back joins into the nasopharynx via the internal nares.

[0523] Pharynx: The part of the laryngopharynx immediately below (inferior to) the inferior part of the nasal cavity and above the esophagus and the superior part of the larynx. The pharynx is conventionally divided into three sections: the nasopharynx (upper pharynx), the part of the pharynx that is nasal, the oropharynx (middle pharynx), the part of the pharynx that is oral, and the laryngopharynx (lower pharynx).

[0524] 5.8.5 Patient interface

[0525] Anti-asphyxia valve (AAV): A component or subcomponent of a mask system that reduces the risk of excessive C02 rebreathing by the patient by venting to atmosphere in a fail-safe manner.

[0526] Elbow: An elbow is an example of a structure that directs the axis of an air flow travelling therethrough to change direction through an angle. In one form, the angle can be approximately 90 degrees. In another form, the angle can be greater or less than 90 degrees. An elbow can have a cross-section that is approximately circular. In another form, an elbow can have a cross-section that is oval or rectangular. In certain forms, an elbow can be rotatable relative to a mating component, for example, about 360 degrees. In certain forms, an elbow can be removable from a mating component, for example, via a snap connection. In certain forms, an elbow can be assembled to a mating component via a one-time snap during manufacturing, but not removable by a patient.

[0527] Frame: A frame will be taken to mean a mask structure that carries the tensile load between two or more connection points to a headgear. A mask frame can be a non-airtight load carrying structure in a mask. However, some forms of mask frame can also be airtight.

[0528] Functional dead space:

[0529] Headgear: Headgear will be taken to mean a form of positioning and stabilising structure designed for use on the head. For example, headgear can comprise a set of one or more support bars, straps and stabilisers configured to position and hold a patient interface in place on the patient's face for delivery of a respiratory therapy. Some straps are formed from a layer of soft, flexible, resilient material, such as a foam and fabric laminate.

[0530] Membrane: A membrane will be taken to mean a typically thin element that is preferably substantially inextensible but not substantially resistant to bending.

[0531] Plenum: A mask plenum will be taken to mean the part of the patient interface which has walls which at least partially enclose a volume which in use has air pressurised within it to above atmospheric pressure. The shell can form part of the walls of the mask plenum.

[0532] Seal: Can refer to the noun form of the structure (seal), or the verb form of the effect (sealing). Two elements can be structured and / or arranged to'seal' or achieve'sealing' therebetween, without the need for a separate'seal' element per se.

[0533] Shell: A shell will be taken to mean a curved and relatively thin structure which has a bendable, stretchable and compressible rigidity. For example, a curved structural wall of a mask can be a shell. In some forms, the shell can be multi-faceted. In some forms, the shell can be air-tight. In some forms, the shell can not be air-tight.

[0534] Reinforcement: A reinforcement will be taken to mean a structural component designed to increase the resistance to bending of another component in at least one direction.

[0535] Support: A support will be taken to mean a structural component designed to increase the resistance to compression of another component in at least one direction.

[0536] Swivel (noun): A sub-assembly of components configured to rotate about a common axis, preferably independently, preferably at low torque. In one form, the swivel can be configured to rotate through an angle of at least 360 degrees. In another form, the swivel can be configured to rotate through an angle of less than 360 degrees. When used in the context of an air delivery conduit, the sub-assembly of components preferably comprises a pair of mating cylindrical conduits. There can be little or no air leakage from the swivel in use.

[0537] Tie (noun): A structure for resisting tension.

[0538] Vent (noun): A structure which allows air flow from inside a mask or conduit to ambient air, for example for effective flushing of exhaled gases. For example, clinically effective flushing can involve a flow of about 10 litres per minute to about 100 litres per minute, depending on the mask design and therapy pressure.

[0539] 5.8.6 Shape of the structure

[0540] Products according to the present technology can include one or more three-dimensional mechanical structures, such as a mask cushion or a propeller. Three-dimensional structures can be joined by two-dimensional surfaces. These surfaces can be distinguished using indicia to describe the relevant surface orientation, location, function, or some other characteristic. For example, a structure can include one or more of an anterior surface, a posterior surface, an inner surface, and an outer surface. In another example, a seal-forming structure can include a (e.g., external) surface that contacts a face and a separate (e.g., underside or internal) surface that does not contact a face. In another example, a structure can include a first surface and a second surface.

[0541] To aid in describing the shape of three-dimensional structures and surfaces, first consider a cross-section through a point p of a surface, see Figures 3B to 3F , which show a cross-section at point p on a surface and resulting examples of planar curves. Figures 3B to 3F An outward normal vector at p is also shown. The outward normal vector at p points in a direction away from the surface. In some examples, the surface is described from the perspective of an imaginary person standing upright on the surface.

[0542] 5.8.6.1 One-dimensional curvature

[0543] The curvature of a planar curve at p can be described as having a sign (e.g., positive, negative) and a magnitude (e.g., the inverse of the radius of a circle that just touches the curve at p).

[0544] Positive curvature: If the curve at p turns away from the outward normal, the curvature at that point will take on a positive value (if the imaginary person leaves point p, they must walk uphill). See Figure 3B (Compare to Figure 3C relatively large positive curvature) and Figure 3C (Compare to Figure 3B relatively small positive curvature). Such curves are often referred to as concave.

[0545] Zero curvature: If the curve at p is a straight line, the curvature will take on a value of zero (if the imaginary person leaves point p, they can walk horizontally, neither uphill nor downhill). See Figure 3D .

[0546] Negative curvature: If the curve at p turns away from the outward normal, the curvature at that point in that direction will take on a negative value (if the imaginary person leaves point p, they must walk downhill). See Figure 3E (Compare to Figure 3F relatively small negative curvature) and Figure 3F (Compare to Figure 3E relatively large negative curvature). Such curves are often referred to as convex.

[0547] 5.8.6.2 Two-dimensional surface curvature

[0548] The description of the shape at a given point on a two-dimensional surface according to the present technology can include a plurality of normal sections. The plurality of sections can cut the surface in planes that include the outward normal (“normal planes”), and each section can be taken in a different direction. Each cross-section yields a planar curve with a corresponding curvature. The different curvatures at the point can have the same sign or different signs. Each curvature at the point has a magnitude, for example a relatively small magnitude. Figures 3B to 3F The planar curves in are examples of such a plurality of sections at a particular point.

[0549] Principal curvatures and directions: The directions of the normal planes in which the curve curvature takes its maximum and minimum values are called principal directions. In Figures 3B to 3F In the example of, the maximum curvature occurs in the direction of Figure 3B In, the minimum curvature occurs in the direction of Figure 3F Thus, and are sections in the principal directions. The principal curvatures at p are the curvatures in the principal directions. Figure 3B and Figure 3F are sections in the principal directions. The principal curvatures at p are the curvatures in the principal directions.

[0550] Region of a surface: A connected set of points on a surface. The set of points in a region can have similar characteristics, for example curvatures or signs.

[0551] Saddle region: A region in which the principal curvatures have opposite signs at each point, i.e. one sign is positive and the other sign is negative (according to the direction in which an imaginary person turns, they can walk up or down).

[0552] Dome region: A region in which the principal curvatures have the same sign at each point, for example both positive (“concave dome”) or both negative (“convex dome”).

[0553] Cylindrical region: A region in which one principal curvature is zero (or, for example, within manufacturing tolerances, zero) and the other principal curvature is non-zero.

[0554] Planar region: A region of a surface in which both principal curvatures are zero (or, for example, within manufacturing tolerances, zero).

[0555] Edge of a surface: The boundary or limit of a surface or region.

[0556] Path: In certain forms of the present technology, a ‘path’ will be taken to mean a path in the mathematical-topological sense, for example a continuous spatial curve on a surface from f(0) to f(1). In certain forms of the present technology, a ‘path’ can be described as a route or a way, including for example a set of points on a surface. (An imaginary person’s path is where they walk on a surface, and is analogous to a garden path).

[0557] Path length: In certain forms of the technology, ‘path length’ will be taken to mean the distance along the surface from f(0) to f(l), i.e. the distance along the path on the surface. There can be more than one path between two points on the surface, and such paths can have different path lengths. (The path length for an imaginary person would be the distance they would have to walk along the path on the surface.

[0558] Straight-line distance: The straight-line distance is the distance between two points on the surface, but without regard to the surface. On a planar region, there will be a path on the surface that has the same path length as the straight-line distance between two points on the surface. On a non-planar surface, there can be no path that has the same path length as the straight-line distance between two points (for an imaginary person, the straight-line distance corresponds to the “like a crow flies” distance).

[0559] 5.8.6.3 Space curve

[0560] Space curve: Unlike a planar curve, a space curve does not have to lie in any particular plane. A space curve can be closed, i.e. have no endpoints. A space curve can be thought of as a one-dimensional piece of three-dimensional space. An imaginary person walking along one strand of a DNA helix walks along a space curve. The helix in a typical person’s left ear comprises a left-handed helix, see Figure 3Q . The helix in a typical person’s right ear comprises a right-handed helix, see Figure 3R . Figure 3S A right-handed helix is shown. The edge of a structure, e.g. the edge of a membrane or impeller, can follow a space curve. In general, a space curve can be described by the curvature and torsion at each point on the space curve. Torsion is a measure of how much a curve twists out of a plane. Torsion has a sign and a magnitude. The torsion at a point on a space curve can be characterized with reference to the tangent vector, the normal vector and the binormal vector at that point.

[0561] Tangent unit vector (or unit tangent vector): For each point on a curve, the vector at that point specifies the direction from the point and the magnitude. The tangent unit vector is the unit vector pointing in the same direction as the curve at that point. If an imaginary person were to fly along a curve and fall from their vehicle at a particular point, the direction of the tangent vector is the direction she would travel.

[0562] Unit normal vector: This tangent vector itself changes as an imaginary person moves along a curve. The unit vector pointing in the direction of the change of the tangent vector is called the unit principal normal vector. It is perpendicular to the tangent vector.

[0563] Binormal unit vector: The binormal unit vector is perpendicular to both the tangent vector and the principal normal vector. Its direction can be determined by the right-hand rule (see, for example, Figure 3P ) or, optionally, by the left-hand rule ( Figure 3O ).

[0564] Osculating plane: A plane containing the unit tangent vector and the unit principal normal vector. See Figure 3O and 3P .

[0565] Twist of a space curve: The twist of a space curve at a point is the magnitude of the rate of change of the binormal unit vector at that point. It measures how much the curve deviates from the osculating plane. A space curve that lies in a plane has zero twist. A space curve that deviates from the osculating plane by a relatively small amount will have a relatively small amount of twist (e.g., a gently inclined helical path). A space curve that deviates from the osculating plane by a relatively large amount will have a relatively large amount of twist (e.g., a sharply inclined helical path). See Figure 3S Since T2 > T1, the amount of twist near the top coil of the helix of Figure 3S is greater than the amount of twist of the bottom coil of the helix of Figure 3S .

[0566] Referring to the right-hand rule of Figure 3P , a space curve that points in the right-hand binormal direction can be considered to have right-hand positive twist (e.g., a right-hand helix as shown in Figure 3S ). A space curve that turns away from the right-hand binormal direction can be considered to have right-hand negative twist (e.g., a left-hand helix).

[0567] Likewise, referring to the left-hand rule (see Figure 3O ), a space curve that points in the left-hand binormal direction can be considered to have left-hand positive twist (e.g., a left-hand helix). Left-hand positive is thus equivalent to right-hand negative. See Figure 3T .

[0568] 5.8.6.4 Holes

[0569] A surface can have one-dimensional holes, e.g., holes bounded by planar curves or by space curves. Thin structures (e.g., membranes) having holes can be described as having one-dimensional holes. See, e.g., the one-dimensional hole in the surface of the structure shown in Figure 3I bounded by planar curves.

[0570] A structure can have two-dimensional holes, e.g., holes bounded by surfaces. For example, a pneumatic tire has a two-dimensional hole bounded by the inner surface of the tire. In another example, a bladder having a cavity for air or gel can have a two-dimensional hole. See, e.g., the bladder of Figure 3L and the exemplary cross-sections in Figure 3M and Figure 3N , which show the inner surface bounding the two-dimensional hole. In yet another example, a catheter can include one-dimensional holes (e.g., at its inlet or at its outlet) and a two-dimensional hole bounded by the inner surface of the catheter. See also Figure 3KA two-dimensional hole bounded by the illustrated surface in the illustrated structure.

[0571] 5.9 Other Notes

[0572] A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.

[0573] Unless otherwise expressly specified herein and provided numerical ranges, it should be understood that every middle point of the range between the upper and lower limits, to the tenth of the lower limit unit, and any other stated or intermediate value within the stated range is also broadly encompassed within the present technology. The upper and lower limits of these intermediate ranges can be independently included in the intermediate ranges, and are also included within the scope of the present technology, subject to any explicitly excluded limits within the stated range. Where a range includes one or both of the extreme values, ranges excluding either or both of those included extreme values are also included in the present technology.

[0574] Further, where one or more values described herein are implemented as part of a portion of the present technology, it should be understood that such values can be approximate, unless otherwise stated, and that such values can be used to the extent permitted or required by practical implementation of the technology to any appropriate significant digits.

[0575] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art to which this application belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present technology, a limited number of the exemplary methods and materials are described herein.

[0576] Where specific materials are indicated for use in constructing components, obvious alternatives of similar properties can be used as substitutes. In addition, unless otherwise specified, any and all components described herein are understood to be capable of being manufactured and thus can be manufactured together or separately.

[0577] It must be noted that as used herein and in the appended claims, the singular form "a", "an", and "the" include plural references unless the context clearly dictates otherwise.

[0578] All publications mentioned herein are incorporated herein by reference in their entirety to disclose and describe the methods and / or materials in connection with which the publications are cited. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present technology is not entitled to antedate such publications. Further, the dates of publication provided can be different in any citations provided herein that refer to online scientific or technical journals or databases. Such dates are also construed as being prior art in the art, with respect to disclosing the subject matter of those publications.

[0579] The terms "comprises" and "comprising" should be interpreted as referring to elements, components, or steps in a non-exclusive manner, referring to the possibility that there are other elements, components, or steps in addition to the listed ones.

[0580] The subject matter headings used herein are for convenience only and are not to be construed as limiting the subject matter described in any way. Subject matter headings are used as a matter of convenience to help identify the subject matter of the various sections of the specification and claims. However, subject matter headings are not to be considered as limiting the subject matter in any way.

[0581] Although the technology herein has been described with reference to particular examples, it is to be understood that the examples are illustrative of the principles and application of the technology. In some instances, terminology and symbols can imply specific details that are not required to practice the technology. For example, although the terms "first" and "second" can be used, unless otherwise specified, they are not intended to denote any order, but can be used to distinguish different elements. Also, although process steps in a method can be described or illustrated in sequence, such order is not essential. Those skilled in the art will recognize that the order can be modified and / or that some steps can be performed simultaneously or even concurrently.

[0582] Thus, it is to be understood that numerous modifications can be made to the illustrative examples and that other arrangements can be devised without departing from the spirit and scope of the technology.

[0583] 5.10 List of Reference Symbols

[0584]

[0585]

[0586]

Claims

1. A patient interface configured to deliver a flow of pressurized breathing gas to an airway of a patient, the patient interface comprising: a cradle base configured to support and form a seal with a nose of the patient in use; two protrusions extending from the cradle base and configured to be inserted into nares of the patient in use, each of the protrusions having an opening formed therein configured to allow continuous flow of air therethrough; and a plenum base forming a plenum chamber with the cradle base, wherein the cradle base is configured such that motion of the cradle base is decoupled from the plenum base, and wherein the plenum base and / or the cradle base is configured to be inflated by the flow of pressurized breathing gas in use to force a sealing surface of the cradle base against the nose of the patient.

2. The patient interface of claim 1, wherein the protrusions are constructed and arranged to seal with an inner periphery of a respective naris in use.

3. The patient interface of claim 1, wherein the protrusions include an end that seals with an inner periphery of a respective naris in use.

4. The patient interface of claim 1, wherein the cradle base includes lateral extensions extending laterally outward on either side of the two protrusions, the lateral extensions being configured to seal against a side or lower portion of each of the patient's alae nasi in use, respectively.

5. The patient interface of claim 1, wherein the cradle base is configured to bend outwardly by the patient's nose when worn by the patient.

6. The patient interface of claim 1, wherein the protrusions have a frustoconical shape.

7. The patient interface of claim 1, wherein the openings of the protrusions are angled relative to a surface of the cradle base from which the protrusions extend.

8. The patient interface of claim 1, wherein the plenum base includes a pair of air inlets on opposite sides.

9. The patient interface of claim 1, wherein a bumper or dam between the cradle base and the plenum base is configured to decouple motion of the cradle base from the plenum base.

10. The patient interface of claim 9, wherein the bumper or dam is not configured to decouple motion between two sealing surfaces.

11. The patient interface of claim 9, wherein the bumper or dam is not configured to decouple motion between a nasal seal and an oral seal.

12. The patient interface of claim 1, wherein the patient interface does not include an oral seal.

13. The patient interface of claim 1, wherein the protrusions do not include a stem.

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