Patient interfaces and frames for a patient interface

Abstract

A frame for a patient interface has first and second side portions, an upper portion connecting the first side portion to the second side portion, and a lower portion which connects an inferior end of the first side portion to an inferior end of the second side portion. The side portions are less flexible than at least one of the upper portion and lower portion. In examples, the frame extends around an outer perimeter of a chassis portion of a patent interface.

Description

PATIENT INTERFACES AND FRAMES FOR A PATIENTINTERFACE1 BACKGROUND OF THE TECHNOLOGY1.1 FIELD OF THE TECHNOLOGY

[0001] The present technology relates to one or more of the screening, diagnosis, monitoring, treatment, prevention and amelioration of respiratory-related disorders. The present technology also relates to medical devices or apparatus, and their use.1.2 DESCRIPTION OF THE RELATED ART1.2.1 Human Respiratory System and its Disorders

[0002] The respiratory system of the body facilitates gas exchange. The nose and mouth form the entrance to the airways of a patient.

[0003] The airways include a series of branching tubes, which become narrower, shorter and more numerous as they penetrate deeper into the lung. The prime function of the lung is gas exchange, allowing oxygen to move from the inhaled air into the venous blood and carbon dioxide to move in the opposite direction. The trachea divides into right and left main bronchi, which further divide eventually into terminal bronchioles. The bronchi make up the conducting airways, and do not take part in gas exchange. Further divisions of the airways lead to the respiratory bronchioles, and eventually to the alveoli. The alveolated region of the lung is where the gas exchange takes place, and is referred to as the respiratory zone. See “ Respiratory Physiology”, by John B. West, Lippincott Williams & Wilkins, 9th edition published 2012.

[0004] A range of respiratory disorders exist. Certain disorders may be characterised by particular events, e.g. apneas, hypopneas, and hyperpneas.

[0005] Examples of respiratory disorders include Obstructive Sleep Apnea (OSA), Cheyne-Stokes Respiration (CSR), respiratory insufficiency, Obesity Hypoventilation Syndrome (OHS), Chronic Obstructive Pulmonary Disease (COPD), Neuromuscular Disease (NMD) and Chest wall disorders.

[0006] Obstructive Sleep Apnea (OSA), a form of Sleep Disordered Breathing (SDB), is characterised by events including occlusion or obstruction of the upper air passage during sleep. It results from a combination of an abnormally small upper airway and the normal loss of muscle tone in the region of the tongue, soft palate and posterior oropharyngeal wall during sleep. The condition causes the affected patient to stop breathing for periods typically of 30 to 120 seconds in duration, sometimes 200A2578192 12.0 1to 300 times per night. It often causes excessive daytime somnolence, and it may cause cardiovascular disease and brain damage. The syndrome is a common disorder, particularly in middle aged overweight males, although a person affected may have no awareness of the problem, e.g. see US Patent No. 4,944,310 (Sullivan).

[0007] Cheyne-Stokes Respiration (CSR) is another form of sleep disordered breathing. CSR is a disorder of a patient's respiratory controller in which there are rhythmic alternating periods of waxing and waning ventilation known as CSR cycles. CSR is characterised by repetitive de-oxygenation and re-oxygenation of the arterial blood. It is possible that CSR is harmful because of the repetitive hypoxia. In some patients CSR is associated with repetitive arousal from sleep, which causes severe sleep disruption, increased sympathetic activity, and increased afterload, e.g. see US Patent No. 6,532,959 (Berthon- Jones).

[0008] Respiratory failure is an umbrella term for respiratory disorders in which the lungs are unable to inspire sufficient oxygen or exhale sufficient CO2 to meet the patient’s needs. Respiratory failure may encompass some or all of the following disorders.

[0009] A patient with respiratory insufficiency (a form of respiratory failure) may experience abnormal shortness of breath on exercise.

[0010] Obesity Hypoventilation Syndrome (OHS) is defined as the combination of severe obesity and awake chronic hypercapnia, in the absence of other known causes for hypoventilation. Symptoms include dyspnea, morning headache and excessive daytime sleepiness.

[0011] Chronic Obstructive Pulmonary Disease (COPD) encompasses any of a group of lower airway diseases that have certain characteristics in common. These include increased resistance to air movement, extended expiratory phase of respiration, and loss of the normal elasticity of the lung. Examples of COPD are emphysema and chronic bronchitis. COPD is caused by chronic tobacco smoking (primary risk factor), occupational exposures, air pollution and genetic factors. Symptoms include: dyspnea on exertion, chronic cough and sputum production.

[0012] Neuromuscular Disease (NMD) is a broad term that encompasses many diseases and ailments that impair the functioning of the muscles either directly via intrinsic muscle pathology, or indirectly via nerve pathology. Some NMD patients are characterised by progressive muscular impairment leading to loss of ambulation, being wheelchair-bound, swallowing difficulties, respiratory muscle weakness and,A2578192 12.0 2eventually, death from respiratory failure. Neuromuscular disorders can be divided into rapidly progressive and slowly progressive: (i) Rapidly progressive disorders: Characterised by muscle impairment that worsens over months and results in death within a few years (e.g. Amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers); (ii) Variable or slowly progressive disorders: Characterised by muscle impairment that worsens over years and only mildly reduces life expectancy (e.g. Limb girdle, Facioscapulohumeral and Myotonic muscular dystrophy). Symptoms of respiratory failure in NMD include: increasing generalised weakness, dysphagia, dyspnea on exertion and at rest, fatigue, sleepiness, morning headache, and difficulties with concentration and mood changes.

[0013] Chest wall disorders are a group of thoracic deformities that result in inefficient coupling between the respiratory muscles and the thoracic cage. The disorders are usually characterised by a restrictive defect and share the potential of long term hypercapnic respiratory failure. Scoliosis and / or kyphoscoliosis may cause severe respiratory failure. Symptoms of respiratory failure include: dyspnea on exertion, peripheral oedema, orthopnea, repeated chest infections, morning headaches, fatigue, poor sleep quality and loss of appetite.

[0014] A range of therapies have been used to treat or ameliorate such conditions. Furthermore, otherwise healthy individuals may take advantage of such therapies to prevent respiratory disorders from arising. However, these have a number of shortcomings.1.2.2 Therapies

[0015] Various respiratory therapies, such as Continuous Positive Airway Pressure (CPAP) therapy, Non-invasive ventilation (NIV), Invasive ventilation (IV), and High Flow Therapy (HFT) have been used to treat one or more of the above respiratory disorders.1.2.2.1 Respiratory pressure therapies

[0016] Respiratory pressure therapy is the application of a supply of air to an entrance to the airways at a controlled target pressure that is nominally positive with respect to atmosphere throughout the patient’s breathing cycle (in contrast to negative pressure therapies such as the tank ventilator or cuirass).

[0017] Continuous Positive Airway Pressure (CPAP) therapy has been used to treat Obstructive Sleep Apnea (OSA). The mechanism of action is that continuousA2578192 12.0 3positive airway pressure acts as a pneumatic splint and may prevent upper airway occlusion, such as by pushing the soft palate and tongue forward and away from the posterior oropharyngeal wall. Treatment of OSA by CPAP therapy may be voluntary, and hence patients may elect not to comply with therapy if they find devices used to provide such therapy one or more of: uncomfortable, difficult to use, expensive and aesthetically unappealing.

[0018] Non-invasive ventilation (NIV) provides ventilatory support to a patient through the upper airways to assist the patient breathing and / or maintain adequate oxygen levels in the body by doing some or all of the work of breathing. The ventilatory support is provided via a non-invasive patient interface. NIV has been used to treat CSR and respiratory failure, in forms such as OHS, COPD, NMD and Chest Wall disorders. In some forms, the comfort and effectiveness of these therapies may be improved.

[0019] Invasive ventilation (IV) provides ventilatory support to patients that are no longer able to effectively breathe themselves and may be provided using a tracheostomy tube or endotracheal tube. In some forms, the comfort and effectiveness of these therapies may be improved.1.2.3 Respiratory Therapy Systems

[0020] These respiratory therapies may be provided by a respiratory therapy system or device. Such systems and devices may also be used to screen, diagnose, or monitor a condition without treating it.

[0021] A respiratory therapy system may comprise a Respiratory Pressure Therapy Device (RPT device), an air circuit, a humidifier, a patient interface, an oxygen source, and data management.1.2.3.1 Patient Interface

[0022] A patient interface may be used to interface respiratory equipment to its wearer, for example by providing a flow of air to an entrance to the airways. The flow of air may be provided via a mask to the nose and / or mouth, a tube to the mouth or a tracheostomy tube to the trachea of a patient. Depending upon the therapy to be applied, the patient interface may form a seal, e.g., with a region of the patient's face, to facilitate the delivery of gas at a pressure at sufficient variance with ambient pressure to effect therapy, e.g., at a positive pressure of about 10 cmH20 relative to ambient pressure. For other forms of therapy, such as the delivery of oxygen, theA2578192 12.0 4patient interface may not include a seal sufficient to facilitate delivery to the airways of a supply of gas at a positive pressure of about 10 cmJUO. For flow therapies such as nasal HFT, the patient interface is configured to insufflate the nares but specifically to avoid a complete seal. One example of such a patient interface is a nasal cannula.

[0023] Certain mask systems may be functionally unsuitable for the present field. For example, purely ornamental masks may be unable to maintain a suitable pressure. Mask systems used for underwater swimming or diving may be configured to guard against ingress of water from an external higher pressure, but not to maintain air internally at a higher pressure than ambient.

[0024] Certain masks may be clinically unfavourable for the present technology e.g. if they block airflow via the nose and only allow it via the mouth.

[0025] Certain masks may be uncomfortable or impractical for the present technology if they require a patient to insert a portion of a mask structure in their mouth to create and maintain a seal via their lips.

[0026] Certain masks may be impractical for use while sleeping, e.g. for sleeping while lying on one’s side in bed with a head on a pillow.

[0027] Certain masks may cause some patients a feeling of claustrophobia, unease and / or may feel overly obtrusive.

[0028] The design of a patient interface presents a number of challenges. The face has a complex three-dimensional shape. The size and shape of noses and heads varies considerably between individuals. Since the head includes bone, cartilage and soft tissue, different regions of the face respond differently to mechanical forces. The jaw or mandible may move relative to other bones of the skull. The whole head may move during the course of a period of respiratory therapy.

[0029] Consequently, some masks suffer from being obtrusive, aesthetically undesirable, costly, poorly fitting, difficult to use, and / or uncomfortable especially when worn for long or when a patient is unfamiliar with a system. Wrongly sized masks can give rise to reduced compliance, reduced comfort and poorer patient outcomes. Masks designed solely for aviators, masks designed as part of personal protection equipment (e.g. filter masks), SCUBA masks, or for the administration of anaesthetics may be tolerable for their original application, but nevertheless such masks may be undesirably uncomfortable to be worn for extended periods of time, e.g., several hours. This discomfort may lead to a reduction in patient compliance with therapy, especially if the mask is to be worn during sleep.A2578192 12.0 5

[0030] CPAP therapy is highly effective to treat certain respiratory disorders, provided patients comply with therapy. If a mask is uncomfortable, or difficult to use a patient may not comply with therapy. Since it is often recommended that a patient regularly wash their mask, if a mask is difficult to clean (e.g., difficult to assemble or disassemble), patients may not clean their mask and this may impact on patient compliance.

[0031] While a mask for other applications (e.g. aviators) may not be suitable for use in treating sleep disordered breathing, a mask designed for use in treating sleep disordered breathing may be suitable for other applications.

[0032] For these reasons, patient interfaces for delivery of CPAP during sleep form a distinct field.

[0033] Many patient interfaces of the prior art comprise a rigid shell or chassis to which a flexible seal is attached. However, there may be advantages to providing a more flexible shell / chassis. PCT publication WO2019235939A1 (the contents of which are included herein by reference) describes various flexible patient interfaces. However, the advantages of the flexible shell or chassis may not be fully realised if the patient interface is used in combination with a rigid frame (e.g. for connecting the chassis to suitable headgear) which reduces the ability of the shell or chassis to flex.1.2.3.1.1 Seal-forming structure

[0034] Patient interfaces may include a seal-forming structure. Since it is in direct contact with the patient’s face, the shape and configuration of the seal -forming structure can have a direct impact the effectiveness and comfort of the patient interface.

[0035] A patient interface may be partly characterised according to the design intent of where the seal-forming structure is to engage with the face in use. In one form of patient interface, a seal-forming structure may comprise a first sub-portion to form a seal around the left naris and a second sub-portion to form a seal around the right naris. In one form of patient interface, a seal-forming structure may comprise a single element that surrounds both nares in use. Such single element may be designed to for example overlay an upper lip region and a nasal bridge region of a face. In one form of patient interface a seal-forming structure may comprise an element that surrounds a mouth region in use, e.g. by forming a seal on a lower lip region of a face. In one form of patient interface, a seal-forming structure may comprise a single element that surrounds both nares and a mouth region in use. These different types ofA2578192 12.0 6patient interfaces may be known by a variety of names by their manufacturer including nasal masks, full-face masks, nasal pillows, nasal puffs and oro-nasal masks.

[0036] A seal -forming structure that may be effective in one region of a patient’s face may be inappropriate in another region, e.g. because of the different shape, structure, variability and sensitivity regions of the patient’s face. For example, a seal on swimming goggles that overlays a patient’s forehead may not be appropriate to use on a patient’s nose.

[0037] Certain seal-forming structures may be designed for mass manufacture such that one design is able to fit and be comfortable and effective for a wide range of different face shapes and sizes. To the extent to which there is a mismatch between the shape of the patient’s face, and the seal-forming structure of the mass- manufactured patient interface, one or both must adapt in order for a seal to form.

[0038] One type of seal -forming structure extends around the periphery of the patient interface, and is intended to seal against the patient's face when force is applied to the patient interface with the seal-forming structure in confronting engagement with the patient's face. The seal-forming structure may include an air or fluid filled cushion, or a moulded or formed surface of a resilient seal element made of an elastomer such as a rubber. With this type of seal-forming structure, if the fit is not adequate, there will be gaps between the seal-forming structure and the face, and additional force will be required to force the patient interface against the face in order to achieve a seal.

[0039] Another type of seal-forming structure incorporates a flap seal of thin material positioned about the periphery of the mask so as to provide a self-sealing action against the face of the patient when positive pressure is applied within the mask. Like the previous style of seal forming portion, if the match between the face and the mask is not good, additional force may be required to achieve a seal, or the mask may leak. Furthermore, if the shape of the seal-forming structure does not match that of the patient, it may crease or buckle in use, giving rise to leaks.

[0040] Another type of seal-forming structure may comprise a friction-fit element, e.g. for insertion into a naris, however some patients find these uncomfortable.A2578192 12.0 7

[0041] Another form of seal-forming structure may use adhesive to achieve a seal. Some patients may find it inconvenient to constantly apply and remove an adhesive to their face.

[0042] A range of patient interface seal-forming structure technologies are disclosed in the following patent applications: WO 1998 / 004310; WO 2006 / 074513; WO 2010 / 135785.

[0043] One form of nasal pillow is found in the Adam Circuit manufactured by Puritan Bennett. Another nasal pillow, or nasal puff is the subject of US Patent 4,782,832 (Trimble et al.), assigned to Puri tan -Bennett Corporation.

[0044] ResMed Inc. has manufactured the following products that incorporate nasal pillows: SWIFT™ nasal pillows mask, SWIFT™ II nasal pillows mask, SWIFT™ LT nasal pillows mask, SWIFT™ FX nasal pillows mask and MIRAGE LIBERTY™ full-face mask. The following patent applications describe examples of nasal pillows masks: International Patent Application WO 2004 / 073778 (describing amongst other things aspects of the SWIFT™ nasal pillows mask), US Patent Application 2009 / 0044808 (describing amongst other things aspects of the SWIFT™ LT nasal pillows mask); International Patent Applications WO 2005 / 063328 and WO 2006 / 130903 (describing amongst other things aspects of the MIRAGE LIBERTY™ full-face mask); International Patent Application WO 2009 / 052560 (describing amongst other things aspects of the SWIFT™ FX nasal pillows mask). / .2.3.1.2 Positioning and Stabilising Structure

[0045] A seal-forming structure of a patient interface used for positive air pressure therapy is subject to the corresponding force of the air pressure to disrupt a seal. Thus a variety of techniques have been used to position the seal-forming structure, and to maintain it in sealing relation with the appropriate portion of the face. Several factors may be considered when comparing different positioning and stabilising techniques. These include: how effective the technique is at maintaining the seal-forming structure in the desired position and in sealed engagement with the face during use of the patient interface; how comfortable the interface is for the patient; whether the patient feels intrusiveness and / or claustrophobia when wearing the patient interface; and aesthetic appeal.

[0046] One technique is the use of adhesives, e.g. see US Patent Application Publication No. US 2010 / 0000534. However, the use of adhesives may be uncomfortable for some.A2578192 12.0 8

[0047] Another technique is the use of one or more straps and / or stabilising harnesses. Many such harnesses suffer from being one or more of ill-fitting, bulky, uncomfortable and awkward to use.1.2.3.1.3 Pressurised Air Conduit

[0048] In one type of treatment system, a flow of pressurised air is provided to a patient interface through a conduit in an air circuit that fluidly connects to the patient interface at a location that is in front of the patient’s face when the patient interface is positioned on the patient’s face during use. The conduit may extend from the patient interface forwards away from the patient’s face. / .2.3.1.4 Pressurised Air Conduit used for Positioning / Stabilising the Seal- Forming Structure

[0049] Another type of treatment system comprises a patient interface in which a tube that delivers pressurised air to the patient’s airways also functions as part of the headgear to position and stabilise the seal-forming portion of the patient interface at the appropriate part of the patient’s face. This type of patient interface may be referred to as having “conduit headgear” or “headgear tubing”. Such patient interfaces allow the conduit in the air circuit providing the flow of pressurised air from a respiratory pressure therapy (RPT) device to connect to the patient interface in a position other than in front of the patient’s face. One example of such a treatment system is disclosed in US Patent Publication No. US 2007 / 0246043, the contents of which are incorporated herein by reference, in which the conduit connects to a tube in the patient interface through a port positioned in use on top of the patient’s head.

[0050] It is desirable for patient interfaces incorporating headgear tubing to be comfortable for a patient to wear over a prolonged duration when the patient is asleep, form an air-tight and stable seal with the patient’s face, while also able to fit a range of patient head shapes and sizes.1.2.3.2 Respiratory Pressure Therapy (RPT) Device

[0051] A respiratory pressure therapy (RPT) device may be used individually or as part of a system to deliver one or more of a number of therapies described above, such as by operating the device to generate a flow of air for delivery to an interface to the airways. The flow of air may be pressure-controlled (for respiratory pressure therapies) or flow-controlled (for flow therapies such as HFT). Thus RPT devices may also act as flow therapy devices. Examples of RPT devices include a CPAP device and a ventilator.A2578192 12.0 9

[0052] The designer of a device may be presented with an infinite number of choices to make. Design criteria often conflict, meaning that certain design choices are far from routine or inevitable. Furthermore, the comfort and efficacy of certain aspects may be highly sensitive to small, subtle changes in one or more parameters.1.2.3.3 Air circuit

[0053] An air circuit is a conduit or a tube constructed and arranged to allow, in use, a flow of air to travel between two components of a respiratory therapy system such as the RPT device and the patient interface. In some cases, there may be separate limbs of the air circuit for inhalation and exhalation. In other cases, a single limb air circuit is used for both inhalation and exhalation.1.2.3.4 Humidifier

[0054] Delivery of a flow of air without humidification may cause drying of airways. The use of a humidifier with an RPT device and the patient interface produces humidified gas that minimizes drying of the nasal mucosa and increases patient airway comfort. In addition, in cooler climates, warm air applied generally to the face area in and about the patient interface is more comfortable than cold air.1.2.3.5 Data Management

[0055] There may be clinical reasons to obtain data to determine whether the patient prescribed with respiratory therapy has been “compliant”, e.g. that the patient has used their RPT device according to one or more “compliance rules”. One example of a compliance rule for CPAP therapy is that a patient, in order to be deemed compliant, is required to use the RPT device for at least four hours a night for at least 21 of 30 consecutive days. In order to determine a patient's compliance, a provider of the RPT device, such as a health care provider, may manually obtain data describing the patient's therapy using the RPT device, calculate the usage over a predetermined time period, and compare with the compliance rule. Once the health care provider has determined that the patient has used their RPT device according to the compliance rule, the health care provider may notify a third party that the patient is compliant.

[0056] There may be other aspects of a patient’s therapy that would benefit from communication of therapy data to a third party or external system.

[0057] Existing processes to communicate and manage such data can be one or more of costly, time-consuming, and error-prone.A2578192 12.0 101.2.3.6 Vent technologies

[0058] Some forms of treatment systems may include a vent to allow the washout of exhaled carbon dioxide. The vent may allow a flow of gas from an interior space of a patient interface, e.g., the plenum chamber, to an exterior of the patient interface, e.g., to ambient.

[0059] The vent may comprise an orifice and gas may flow through the orifice in use of the mask. Many such vents are noisy. Others may become blocked in use and thus provide insufficient washout. Some vents may be disruptive of the sleep of a bed partner 1100 of the patient 1000, e.g. through noise or focussed airflow.

[0060] ResMed Inc. has developed a number of improved mask vent technologies, e.g. see International Patent Application Publication No. WO 1998 / 034665; International Patent Application Publication No. WO 2000 / 078381; US Patent No. 6,581,594; US Patent Application Publication No. US 2009 / 0050156; US Patent Application Publication No. 2009 / 0044808.

[0061] Table of noise of prior masks (ISO 17510-2:2007, 10 cmH20 pressure at Im)A2578192 12.0 11

[0062] (* one specimen only, measured using test method specified in ISO 3744 in CPAP mode at 10 cmH20)1.2.4 Screening, Diagnosis, and Monitoring Systems

[0063] Polysomnography (PSG) is a conventional system for diagnosis and monitoring of cardio-pulmonary disorders, and typically involves expert clinical staff to apply the system. PSG typically involves the placement of 15 to 20 contact sensors on a patient in order to record various bodily signals such as electroencephalography (EEG), electrocardiography (ECG), electrooculograpy (EOG), electromyography (EMG), etc. PSG for sleep disordered breathing has involved two nights of observation of a patient in a clinic, one night of pure diagnosis and a second night of titration of treatment parameters by a clinician. PSG is therefore expensive and inconvenient. In particular, it is unsuitable for home screening / diagnosis / monitoring of sleep disordered breathing.

[0064] Screening and diagnosis generally describe the identification of a condition from its signs and symptoms. Screening typically gives a true / false resultA2578192 12.0 12indicating whether or not a patient’s SDB is severe enough to warrant further investigation, while diagnosis may result in clinically actionable information. Screening and diagnosis tend to be one-off processes, whereas monitoring the progress of a condition can continue indefinitely. Some screening / diagnosis systems are suitable only for screening / diagnosis, whereas some may also be used for monitoring.

[0065] Clinical experts may be able to screen, diagnose, or monitor patients adequately based on visual observation of PSG signals. However, there are circumstances where a clinical expert may not be available, or a clinical expert may not be affordable. Different clinical experts may disagree on a patient’s condition. In addition, a given clinical expert may apply a different standard at different times.2 BRIEF SUMMARY OF THE TECHNOLOGY

[0066] The present technology is directed towards providing medical devices used in the screening, diagnosis, monitoring, amelioration, treatment, or prevention of respiratory disorders having one or more of improved comfort, cost, efficacy, ease of use and manufacturability.

[0067] A first aspect of the present technology relates to apparatus used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respiratory disorder.

[0068] Another aspect of the present technology relates to methods used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respiratory disorder.

[0069] An aspect of certain forms of the present technology is to provide methods and / or apparatus that improve the compliance of patients with respiratory therapy.

[0070] One form of the present technology comprises a positioning and stabilising structure configured 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 includes at least one strap.

[0071] One form of the present technology comprises a patient interface comprising a plenum chamber, a seal-forming structure, and a positioning and stabilising structure.

[0072] One form of the present technology comprises patient interface comprising a plenum chamber pressurisable to a therapeutic pressure of at least 4A2578192 12.0 13cmH20 above ambient air pressure. The plenum chamber includes at least one plenum chamber inlet port sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient. The patient interface also comprises a seal-forming structure that is 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 has a hole therein such that the flow of air at said therapeutic pressure is delivered to at least an entrance to the patient’s nares. The seal-forming structure is constructed and arranged to maintain said therapeutic pressure in the plenum chamber throughout the patient’s respiratory cycle in use. The patient interface also comprises 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.

[0073] Another aspect of one form of the present technology is a series of modular elements that may be interconnected in order to form different styles of patient interfaces.

[0074] In one form, there are at least two versions or styles of each modular element. The versions or styles may be interchangeably used with one another in order to form different modular assemblies.

[0075] Another form of the present technology comprises a patient interface constructed and arranged to form a seal with a region of the patient’s face, including a nose bridge region, and surrounding an entrance to the patient’s airways, the patient interface including: a plenum chamber defined, at least in part, by a chassis portion, wherein at least a portion of a perimeter of the chassis portion comprises a flange, and wherein at least the portion of the chassis portion, including the flange, is relatively flexible, a sealforming structure, wherein the seal forming structure includes a textile layer, wherein the textile layer has a patient-contacting side and non-patient contacting side, and wherein the non-patient contacting side of the textile layer is bonded or otherwise secured to the flange such that, in use, the patient-contacting side of the textile layer contacts the patient’s face; and wherein the perimeter of the chassis includes a cutout, which in use corresponds to at least the nose bridge region of the patient’s face, wherein the textile layer covers the cutout.

[0076] In examples, a foam layer is provided between the flange and the textile layer.A2578192 12.0 14

[0077] A patient interface constructed and arranged to form a seal with a region of the patient’s face, including a nose bridge region, and surrounding an entrance to the patient’s airways, the patient interface including: a plenum chamber defined, at least in part, by a chassis portion, wherein at least the portion of the chassis portion is relatively flexible; a seal-forming structure connected to the chassis portion, wherein the seal forming structure includes a textile layer, wherein the perimeter of the chassis portion includes a cutout, which in use corresponds to at least the nose bridge region of the patient’s face, wherein the textile layer covers the cutout, and wherein an anterior wall of the chassis portion comprises a stiffening portion, the stiffening portion provided substantially adjacent a boundary between the anterior wall and a posterior wall of the chassis portion.

[0078] In examples: a) the stiffening portion is elongate and is positioned substantially parallel to the boundary between the anterior wall and the posterior wall; b) a ratio of the height of the stiffening portion to the width of the stiffening portion is at least 2: 1; c) the stiffening portion is made from a different material to the anterior wall of the chassis portion; d) the stiffening portion is made from a less flexible material than the anterior wall of the chassis portion; e) the stiffening portion is made from a rigid or semi-rigid material; f) the stiffening portion is made from polycarbonate or polyester; g) the stiffening portion is overmoulded to the chassis portion, or are affixed to the chassis portion after moulding of the chassis portion; h) the stiffening portion is embedded in the anterior wall; i) no part of the stiffening portion is not encased within the anterior wall; j) a portion of the stiffening portion is not encased within the anterior wall;A2578192 12.0 15k) the portion of the stiffening portion which is not encased within the anterior wall is provided with means for connection to a frame; l) the chassis portion is made from a material having a Shore A hardness of between 30 and 60; m) the cutout extends to an anterior wall of the chassis portion; n) the portion of the cutout in the anterior wall of the chassis portion has a substantially inverted teardrop or inverted triangle shape; o) no flange is provided to the cutout; p) the textile layer is connected to a flange; q) the flange terminates at sides of nose portions which are configured to engage portions of the sides of the patient’s nose corresponding to the nasal bone; r) the sides of nose portions are configured to avoid engagement with the portion of the patient’s nose corresponding to the greater alar cartilage; s) the sides of nose portions are configured to avoid engagement with the portion of the patient’s nose corresponding to the septum cartilage; t) the flange curves inward; u) the flange has a substantially “C” shape profile; v) a curvature of the flange is substantially continuous with a curvature of an immediately adjacent portion of the chassis portion; w) the flange has a thickness of between 2.5mm and 0.5mm; x) the flange has a free edge; y) the thickness of the flange tapers down toward the free edge; z) at least portions of the textile layer extend beyond the free edge of the flange to form at least one unsupported portion of the textile layer; aa) the unsupported portion of the textile layer has a uniform width; bb)the unsupported portion has a width of substantially 2mm; cc) the textile layer comprises unsupported portions having varying widths; dd)the textile layer is formed from a single piece of textile; ee) the textile layer is cut from a flat sheet of textile; ff) the textile layer comprises a stretchable material; gg)the textile layer is substantially impermeable to air; hh) one or more regions of, or all of, the textile layer allow a limited flow of air; ii) the textile layer comprises a thin layer of elastomer;A2578192 12.0 16jj) the textile layer comprises a main portion, a superior portion, and a necked portion between the main and superior portions; kk) the necked portion of the textile layer forms a nasal bridge sealing portion;11) the nasal bridge sealing portion has a concave shape; mm) at least a portion of the flange is not covered by the textile layer, and wherein the portion of the flange which is not covered by the textile layer is configured to seal against the patient’s face; nn)the chassis portion comprises a shell portion which is more rigid than the remainder of the chassis portion; oo)the shell portion does not extend to the lateral or inferior walls of the chassis portion; pp) the shell portion has a Shore A hardness of greater than 60; qq)the shell portion is made from a nylon, a polyester, a semi-rigid elastomer, or silicone; rr) the shell portion forms at least part of an anterior wall of the chassis portion; ss) the cutout extends to the shell portion; tt) the anterior wall of the chassis portion comprises a layer of relatively flexible material with the shell portion connected to an outer surface of the relatively flexible material; and / or uu) The patient interface comprises a second stiffening portion provided to a laterally opposite side of the anterior wall of the chassis portion.

[0079] According to one form of the technology there is provided a frame for a patient interface, the frame comprising first and second side portions, an upper portion connecting the first side portion to the second side portion, the frame further comprising a lower portion which connects an inferior end of the first side portion to an inferior end of the second side portion, wherein the side portions are less flexible than at least one of the upper portion and lower portion.

[0080] In examples, a) the upper portion is connected to the superior ends of the first and second side portions; b) the upper portion is connected between the superior and inferior ends of the side portions, towards the superior ends; c) at least one headgear connector is connected to each of the side portions.A2578192 12.0 17d) the inferior ends of the side portions overlie the patient’s cheeks below the patient’s mouth; e) the superior ends of the side portions overlie the patient’s cheeks, between the patient’s nose and mouth; f) the superior ends of the side portions lie adjacent the patient’s nose; g) the side portions are between 1 mm and 4 mm thick; h) each side portion comprises at least one connection point for connection to a cushion module; i) each side portion comprises a plurality of connection points for connection to a cushion module; j) the connection points comprise apertures configured to receive projecting portions provided to the cushion module; k) the upper portion is substantially U-shaped; l) the upper portion is substantially straight; m) side portions, upper portion and lower portion are formed integrally as one piece; n) one or both of the upper and lower portions are formed in a separate step from the formation of the side portions; o) one or both of the upper and lower portions are formed by an overmoulding process; p) one or both of the upper and lower portions are connected to the side portions by a connecting means; q) each side portion comprises an upper arm, wherein each upper arm comprises a headgear connector; r) the headgear connector comprises a slot configured to receive a headgear strap; and / or s) each upper arm comprises a flexible portion.

[0081] According to one form of the technology there is provided a patient interface comprising: a plenum chamber defined, at least in part by a chassis portion, a seal forming structure connected to the chassis portion, and a frame, the frame comprising first and second side portions, an upper portion connecting a superior end of the first side portion to a superior end of the second side portion, the frame further comprising a lower portion which connects an inferior end of the first side portion toA2578192 12.0 18an inferior end of the second side portion, wherein the frame extends around an outer perimeter of the chassis portion.

[0082] In examples; a) an anterior wall of the chassis portion comprises a superior cutout; b) the upper portion of the frame is configured to extend around a perimeter of the cutout; and / or c) the upper portion of the frame is configured to extend below the cutout.

[0083] According to one form of the technology there is provided a patient interface comprising a plenum chamber defined, at least in part by a chassis portion, a seal forming structure connected to the chassis portion, a first frame portion and a second frame portion, wherein the frame portions are connectable to the chassis portion but the first frame portion is not connected to the second frame portion, each frame portion extending along a lateral edge of the chassis portion, and wherein each frame portion comprises at least one headgear connector.

[0084] In examples: a) the chassis portion is flexible b) the inferior ends of the side portions overlie the patient’s cheeks below the patient’s mouth; c) the superior ends of the side portions overlie the patient’s cheeks, between the patient’s nose and mouth; d) the superior ends of the side portions lie adjacent the patient’s nose; e) the side portions are between 1 mm and 4 mm thick; f) each side portion comprises at least one connection point for connection to the cushion module; g) each side portion comprises a plurality of connection points for connection to a cushion module; and / or h) the connection points comprise apertures configured to receive projecting portions provided to the cushion module.

[0085] According to one form of the present technology there is provided a frame for a patient interface comprising a pair of upper arms, a pair of lower arms, the upper and lower arms connected to a central portion, wherein the central portion comprisesA2578192 12.0 19an aperture configured to allow an air circuit connector to extend through the central portion, and wherein each of the upper and lower arms comprises a headgear connection means.

[0086] In examples: a) the frame may be moulded in one piece; b) each upper arm may comprise a flexible portion; and / or c) the frame may comprise venting features adjacent the aperture.

[0087] According to one form of the technology there is provided a method of manufacturing a frame for a patient interface, the method comprising: i. manufacturing a central frame portion; ii. manufacturing a pair of arm portions, each arm portion comprising a superior arm portion, a medial portion and an inferior arm portion; and iii. connecting the arm portions to opposite lateral sides of the central frame portion.

[0088] In examples, the superior and inferior arm portions extend away from the central frame portion after connection to the central frame portion.

[0089] In examples, an alignment formation is provided to at least one of the central frame portion and the arm portions to assist in providing a correct alignment between the central frame portion and the arm portions.

[0090] In examples, the arm portions are connected to the central frame portion by an adhesive.

[0091] Another aspect of one form of the present technology is a patient interface that is moulded or otherwise constructed with a perimeter shape which is complementary to that of an intended wearer.

[0092] An aspect of one form of the present technology is a method of manufacturing apparatus.

[0093] Another aspect of one form of the present technology is a method of assembling a modular system comprising selecting a positioning and stabilisingA2578192 12.0 20structure, and connecting the positioning and stabilising structure to either a first cushion or a second cushion.

[0094] An aspect of certain forms of the present technology is a medical device that is easy to use, e.g. by a person who does not have medical training, by a person who has limited dexterity, vision or by a person with limited experience in using this type of medical device.

[0095] An aspect of one form of the present technology is a portable RPT device that may be carried by a person, e.g., around the home of the person.

[0096] An aspect of one form of the present technology is a patient interface that may be washed in a home of a patient, e.g., in soapy water, without requiring specialised cleaning equipment. An aspect of one form of the present technology is a humidifier tank that may be washed in a home of a patient, e.g., in soapy water, without requiring specialised cleaning equipment.

[0097] The methods, systems, devices and apparatus described may be implemented so as to improve the functionality of a processor, such as a processor of a specific purpose computer, respiratory monitor and / or a respiratory therapy apparatus. Moreover, the described methods, systems, devices and apparatus can provide improvements in the technological field of automated management, monitoring and / or treatment of respiratory conditions, including, for example, sleep disordered breathing.

[0098] Of course, portions of the aspects may form sub-aspects of the present technology. Also, various ones of the sub-aspects and / or aspects may be combined in various manners and also constitute additional aspects or sub-aspects of the present technology.

[0099] Other features of the technology will be apparent from consideration of the information contained in the following detailed description, abstract, drawings and claims.3 BRIEF DESCRIPTION OF THE DRAWINGS

[0100] The present technology is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which like reference numerals refer to similar elements including:A2578192 12.0 213.1 RESPIRATORY THERAPY SYSTEMS

[0101] Fig. 1 A shows a system including a patient 1000 wearing a patient interface 3000, in the form of nasal pillows, receiving 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.

[0102] Fig. IB shows a system including a patient 1000 wearing a patient interface 3000, in the form of a nasal mask, receiving 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.

[0103] Fig. 1C shows a system including a patient 1000 wearing a patient interface 3000, in the form of a full -face mask, receiving 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.3.2 RESPIRATORY SYSTEM AND FACIAL ANATOMY

[0104] Fig. 2 A shows an overview of a human respiratory system including the nasal and oral cavities, the larynx, vocal folds, oesophagus, trachea, bronchus, lung, alveolar sacs, heart and diaphragm.

[0105] Fig. 2B shows a view of a human upper airway including the nasal cavity, nasal bone, lateral nasal cartilage, greater alar cartilage, nostril, lip superior, lip inferior, larynx, hard palate, soft palate, oropharynx, tongue, epiglottis, vocal folds, oesophagus and trachea.

[0106] Fig. 2C is a front view of a face with several features of surface anatomy identified including the lip superior, upper vermilion, lower vermilion, lip inferior, mouth width, endocanthion, a nasal ala, nasolabial sulcus and cheilion. Also indicated are the directions superior, inferior, radially inward and radially outward.

[0107] Fig. 2D is a side view of a head with several features of surface anatomy identified including glabella, sellion, pronasale, subnasale, lip superior, lip inferior, supramenton, nasal ridge, alar crest point, otobasion superior and otobasion inferior. Also indicated are the directions superior & inferior, and anterior & posterior.

[0108] Fig. 2E is a further side view of a head. The approximate locations of the Frankfort horizontal and nasolabial angle are indicated. The coronal plane is also indicated.A2578192 12.0 22

[0109] Fig. 2F shows a base view of a nose with several features identified including naso-labial sulcus, lip inferior, upper Vermilion, naris, subnasale, columella, pronasale, the major axis of a naris and the midsagittal plane.

[0110] Fig. 2G shows a side view of the superficial features of a nose.

[0111] Fig. 2H shows subcutaneal structures of the nose, including lateral cartilage, septum cartilage, greater alar cartilage, lesser alar cartilage, sesamoid cartilage, nasal bone, epidermis, adipose tissue, frontal process of the maxilla and fibrofatty tissue.

[0112] Fig. 21 shows a medial dissection of a nose, approximately several millimeters from the midsagittal plane, amongst other things showing the septum cartilage and medial crus of greater alar cartilage.

[0113] Fig. 2 J shows a front view of the bones of a skull including the frontal, nasal and zygomatic bones. Nasal concha are indicated, as are the maxilla, and mandible.

[0114] Fig. 2K shows a lateral view of a skull with the outline of the surface of a head, as well as several muscles. The following bones are shown: frontal, sphenoid, nasal, zygomatic, maxilla, mandible, parietal, temporal and occipital. The mental protuberance is indicated. The following muscles are shown: digastricus, masseter, sternocleidomastoid and trapezius.

[0115] Fig. 2L shows an anterolateral view of a nose.3.3 PATIENT INTERFACE

[0116] Fig. 3A shows a patient interface in the form of a nasal mask in accordance with one form of the present technology.

[0117] Fig. 3A-1 shows forces acting on the patient interface of Fig. 3A, while in use.

[0118] Fig. 3B shows a schematic of a cross-section through a structure at a point. An 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 magnitude of the curvature shown in Fig. 3C.

[0119] Fig. 3C shows a schematic of a cross-section through a structure at a point. An outward normal at the point is indicated. The curvature at the point has a positive sign, and a relatively small magnitude when compared to the magnitude of the curvature shown in Fig. 3B.A2578192 12.0 23

[0120] Fig. 3D shows a schematic of a cross-section through a structure at a point. An outward normal at the point is indicated. The curvature at the point has a value of zero.

[0121] Fig. 3E shows a schematic of a cross-section through a structure at a point. An outward normal at the point is indicated. The curvature at the point has a negative sign, and a relatively small magnitude when compared to the magnitude of the curvature shown in Fig. 3F.

[0122] Fig. 3F shows a schematic of a cross-section through a structure at a point. An outward normal at the point is indicated. The curvature at the point has a negative sign, and a relatively large magnitude when compared to the magnitude of the curvature shown in Fig. 3E.

[0123] Fig. 3G shows a cushion for a mask that includes two pillows. An exterior surface of the cushion is indicated. An edge of the surface is indicated. Dome and saddle regions are indicated.

[0124] Fig. 3H shows a cushion for a mask. An exterior surface of the cushion is indicated. An edge of the surface is indicated. 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.

[0125] Fig. 31 shows the surface of a structure, with a one dimensional hole in the surface. The illustrated plane curve forms the boundary of a one dimensional hole.

[0126] Fig. 3J shows a cross-section through the structure of Fig.31. The illustrated surface bounds a two dimensional hole in the structure of Fig. 31.

[0127] Fig. 3K shows a perspective view of the structure of Fig. 31, including the two dimensional hole and the one dimensional hole. Also shown is the surface that bounds a two dimensional hole in the structure of Fig. 31.

[0128] Fig. 3L shows a mask having an inflatable bladder as a cushion.

[0129] Fig. 3M shows a cross-section through the mask of Fig. 3L, and shows the interior surface of the bladder. The interior surface bounds the two dimensional hole in the mask.

[0130] Fig. 3N shows a further cross-section through the mask of Fig. 3L. The interior surface is also indicated.

[0131] Fig. 30 illustrates a left-hand rule.

[0132] Fig. 3P illustrates a right-hand rule.

[0133] Fig. 3Q shows a left ear, including the left ear helix.A2578192 12.0

[0134] Fig. 3R shows a right ear, including the right ear helix.

[0135] Fig. 3S shows a right-hand helix.

[0136] Fig. 3T shows a view of a mask, including the sign of the torsion of the space curve defined by the edge of the sealing membrane in different regions of the mask.

[0137] Fig. 3U shows a view of a plenum chamber 3200 showing a sagittal plane and a mid-contact plane.

[0138] Fig. 3V shows a view of a posterior of the plenum chamber of Fig. 3U. The direction of the view is normal to the mid-contact plane. The sagittal plane in Fig. 3 V bisects the plenum chamber into left-hand and right-hand sides.

[0139] Fig. 3W shows a cross-section through the plenum chamber of Fig. 3 V, the cross-section being taken at the sagittal plane shown in Fig. 3 V. A ‘mid-contact’ plane is shown. The mid-contact plane is perpendicular to the sagittal plane. The orientation of the mid-contact plane corresponds to the orientation of a chord 3210 which lies on the sagittal plane and just touches the cushion of the plenum chamber at two points on the sagittal plane: a superior point 3220 and an inferior point 3230. Depending on the geometry of the cushion in this region, the mid-contact plane may be a tangent at both the superior and inferior points.

[0140] Fig. 3X shows the plenum chamber 3200 of Fig. 3U in position for use on a face. The sagittal plane of the plenum chamber 3200 generally coincides with the midsagittal plane of the face when the plenum chamber is in position for use. The mid-contact plane corresponds generally to the ‘plane of the face’ when the plenum chamber is in position for use. In Fig. 3X the plenum chamber 3200 is that of a nasal mask, and the superior point 3220 sits approximately on the sellion, while the inferior point 3230 sits on the lip superior.3.4 HEADGEAR

[0141] Fig. 4 shows a perspective view of headgear straps which are suitable for use with some forms of the technology.3.5 HUMIDIFIER

[0142] Fig. 5A shows an isometric view of a humidifier in accordance with one form of the present technology.

[0143] Fig. 5B shows an isometric view of a humidifier in accordance with one form of the present technology, showing a humidifier reservoir 5110 removed from the humidifier reservoir dock 5130.A2578192 12.0 253.6 BREATHING WAVEFORMS

[0144] Fig. 6 shows a model typical breath waveform of a person while sleeping.3.7 CUSHION MODULES, PATIENT INTERFACES AND FRAMES OF THE PRESENT TECHNOLOGY

[0145] Fig. 7 shows a perspective view of a cushion module of one form of the technology.

[0146] Fig. 7A shows a front view of the chassis portion of the cushion module of Fig. 7, with the seal forming structure removed.

[0147] Fig. 7B shows a rear view of the cushion module of Fig. 7 with the chassis portion shown as transparent.

[0148] Fig. 7C shows a front view of the cushion module of Fig. 7 with the chassis portion shown as transparent.

[0149] Fig. 8 shows a front view of a patient interface according to one form of the technology.

[0150] Fig. 8 A shows a front view of the frame of the patient interface of Fig. 8, with the cushion module removed.

[0151] Fig. 8B shows a side view of the patient interface of Fig. 8.

[0152] Fig. 8C shows a side view of the frame of the patient interface of Fig. 8, with the cushion module removed.

[0153] Fig. 8D shows an enlarged horizontal cross-section view through the patient interface of Fig. 8, showing portions of the anterior and posterior walls of the cushion module and one frame side portion, and showing forces on the patient interface when in use.

[0154] Fig. 9 shows a perspective view of a patient interface according to another form of the technology in use on a patient’s face.

[0155] Fig. 10 shows a perspective view of a frame of a patient interface according to another form of the technology.

[0156] Fig. 11 shows a front view of a patient interface according to one form of the technology.

[0157] Fig. 11A shows a side view of the patient interface of Fig. 11.

[0158] Fig. 1 IB shows a side view of one frame portion of the patient interface ofFig. 11, with the cushion module removed.

[0159] Fig. 12 shows a perspective view of a frame of a patient interface according to another form of the technology with an inlet port not shown.A2578192 12.0 26

[0160] Fig. 13 shows a perspective view of a patient interface according to another form of the technology in use on a patient’s face.

[0161] Fig. 14A shows a front view of a cushion module according to another form of the technology, with stiffening portions shown in hidden detail.

[0162] Fig. 14B shows a side view of the cushion module of Fig. 14A.

[0163] Fig. 15 shows a side view of a cushion module according to another form of the technology, with a stiffening portion shown in hidden detail.

[0164] Fig. 16 shows a side view of a cushion module according to another form of the technology, with a stiffening portion shown in hidden detail.

[0165] Fig. 17 shows a side view of a cushion module according to another form of the technology, with a stiffening portion shown in hidden detail.

[0166] Fig. 18 shows a front view of a cushion module according to another form of the technology, with an outline of a frame shown and with stiffening portions shown in hidden detail.

[0167] Fig. 19 shows a front view of a cushion module according to another form of the technology, with a stiffening portion shown in hidden detail.

[0168] Fig. 20 A show a front view of a cushion module of one form of the technology with an inlet port not shown.

[0169] Fig. 20B shows a side view of the cushion module of Fig. 20A.

[0170] Fig. 21 shows a rear perspective view of a cushion module of one form of the technology.

[0171] Fig. 22 shows a front perspective view of a cushion module of one form of the technology.

[0172] Fig. 23 shows a front perspective view of a cushion module of one form of the technology.

[0173] Fig. 24 shows a perspective view of a patent interface of the present technology.

[0174] Fig. 24 A shows an exploded view of the frame of the patient interface shown in Fig. 24.

[0175] Fig. 24B shows a front view of the frame of the patient interface shown in Fig. 24.

[0176] Fig. 24C shows a cross section view through the frame of the patient interface shown in Fig. 24 through section E-E as marked in Fig. 24B.A2578192 12.0 274 DETAILED DESCRIPTION OF EXAMPLES OF THETECHNOLOGY

[0177] 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 may vary. It is also to be understood that the terminology used in this disclosure is for the purpose of describing only the particular examples discussed herein, and is not intended to be limiting.

[0178] The following description is provided in relation to various examples which may share one or more common characteristics and / or features. It is to be understood that one or more features of any one example may be combinable with one or more features of another example or other examples. In addition, any single feature or combination of features in any of the examples may constitute a further example.4.1 THERAPY

[0179] In one form, the present technology comprises a method for treating a respiratory disorder comprising applying positive pressure to the entrance of the airways of a patient 1000.

[0180] In certain examples of the present technology, a supply of air at positive pressure is provided to the nasal passages of the patient via one or both nares.

[0181] In certain examples of the present technology, mouth breathing is limited, restricted or prevented.4.2 RESPIRATORY THERAPY SYSTEMS

[0182] In one form, the present technology comprises a respiratory therapy system for treating a respiratory disorder. The respiratory therapy system may comprise an RPT device 4000 for supplying a flow of air to the patient 1000 via an air circuit 4170 and a patient interface 3000.4.3 PATIENT INTERFACE

[0183] A non-invasive patient interface 3000, such as that shown in Fig. 3A, in accordance with one aspect of the present technology comprises the following functional aspects: a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilising structure 3300, a vent 3400, one form of connection port 3600 for connection to air circuit 4170, and a forehead support 3700. In some forms a functional aspect may be provided by one or more physical components. In someA2578192 12.0 28forms, one physical component may provide one or more functional aspects. In use the seal -forming structure 3100 is arranged to surround an entrance to the airways of the patient so as to maintain positive pressure at the entrance(s) to the airways of the patient 1000. The sealed patient interface 3000 is therefore suitable for delivery of positive pressure therapy.

[0184] If a patient interface is unable to comfortably deliver a minimum level of positive pressure to the airways, the patient interface may be unsuitable for respiratory pressure therapy.

[0185] The patient interface 3000 in accordance with one form of the present technology is constructed and arranged to be able to provide a supply of air at a positive pressure above the ambient, for example at least 2, 4, 6, 10, or 20 cmH20 with respect to ambient.4.3.1 Seal-forming structure

[0186] In one form of the present technology, a seal-forming structure 3100 provides a target seal-forming region, and may additionally provide a cushioning function. The target seal-forming region is a region on the seal -forming structure 3100 where sealing may occur. The region where sealing actually occurs- the actual sealing surface- may change within a given treatment session, from day to day, and from patient to patient, depending on a range of factors including for example, where the patient interface was placed on the face, tension in the positioning and stabilising structure and the shape of a patient’s face.

[0187] In one form the target seal -forming region is located on an outside surface of the seal-forming structure 3100.

[0188] In certain forms of the present technology, the seal-forming structure 3100 is constructed from a biocompatible material, e.g. silicone rubber.

[0189] A seal -forming structure 3100 in accordance with the present technology may be constructed from a soft, flexible, resilient material such as silicone.

[0190] In certain forms of the present technology, a system is provided comprising more than one a seal-forming structure 3100, each being configured to correspond to a different size and / or shape range. For example the system may comprise one form of a seal-forming structure 3100 suitable for a large sized head, but not a small sized head and another suitable for a small sized head, but not a large sized head.A2578192 12.0 294.3.1.1 Sealing mechanisms

[0191] In one form, the seal -forming structure includes a sealing flange utilizing a pressure assisted sealing mechanism. In use, the sealing flange can readily respond to a system positive pressure in the interior of the plenum chamber 3200 acting on its underside to urge it into tight sealing engagement with the face. The pressure assisted mechanism may act in conjunction with elastic tension in the positioning and stabilising structure.

[0192] In one form, the seal -forming structure 3100 comprises a sealing flange and a support flange. The sealing flange comprises a relatively thin member with a thickness of less than about 1mm, for example about 0.25mm to about 0.45mm, which extends around the perimeter of the plenum chamber 3200. Support flange may be relatively thicker than the sealing flange. The support flange is disposed between the sealing flange and the marginal edge of the plenum chamber 3200, and extends at least part of the way around the perimeter. The support flange is or includes a springlike element and functions to support the sealing flange from buckling in use.

[0193] In one form, the seal-forming structure may comprise a compression sealing portion or a gasket sealing portion. In use the compression sealing portion, or the gasket sealing portion is constructed and arranged to be in compression, e.g. as a result of elastic tension in the positioning and stabilising structure.

[0194] In one form, the seal -forming structure comprises a tension portion. In use, the tension portion is held in tension, e.g. by adjacent regions of the sealing flange.

[0195] In one form, the seal -forming structure comprises a region having a tacky or adhesive surface.

[0196] In certain forms of the present technology, a seal -forming structure may comprise one or more of a pressure-assisted sealing flange, a compression sealing portion, a gasket sealing portion, a tension portion, and a portion having a tacky or adhesive surface.4.3.1.2 Nose bridge or nose ridge region

[0197] In one form, the non-invasive patient interface 3000 comprises a sealforming structure that forms a seal in use on a nose bridge region or on a nose-ridge region of the patient's face.A2578192 12.0 30

[0198] In one form, the seal -forming structure includes a saddle-shaped region constructed to form a seal in use on a nose bridge region or on a nose-ridge region of the patient's face.4.3.1.3 Upper lip region

[0199] In one form, the non-invasive patient interface 3000 comprises a sealforming structure that forms a seal in use on an upper lip region (that is, the lip superior) of the patient's face.

[0200] In one form, the seal-forming structure includes a saddle-shaped region constructed to form a seal in use on an upper lip region of the patient's face.4.3.1.4 Chin-region

[0201] In one form the non-invasive patient interface 3000 comprises a sealforming structure that forms a seal in use on a chin-region of the patient's face.

[0202] In one form, the seal-forming structure includes a saddle-shaped region constructed to form a seal in use on a chin-region of the patient's face.4.3.1.5 Forehead region

[0203] In one form, the seal-forming structure that forms a seal in use on a forehead region of the patient's face. In such a form, the plenum chamber may cover the eyes in use.4.3.1.6 Nasal pillows

[0204] In one form the seal-forming structure of the non-invasive patient interface 3000 comprises a pair of nasal puffs, or nasal pillows, each nasal puff or nasal pillow being constructed and arranged to form a seal with a respective naris of the nose of a patient.

[0205] Nasal pillows in accordance with an aspect of the present technology include: a frusto-cone, at least a portion of which forms a seal on an underside of the patient's nose, a stalk, a flexible region on the underside of the frusto-cone and connecting the frusto-cone to the stalk. In addition, the structure to which the nasal pillow of the present technology is connected includes a flexible region adjacent the base of the stalk. The flexible regions can act in concert to facilitate a universal joint structure that is accommodating of relative movement both displacement and angular of the frusto-cone and the structure to which the nasal pillow is connected. For example, the frusto-cone may be axially displaced towards the structure to which the stalk is connected.A2578192 12.0 314.3.1.7 Nose-only Masks

[0206] In one form, the patient interface 3000 comprises a seal-forming structure 3100 configured to seal around an entrance to the patient’s nasal airways but not around the patient’s mouth. The seal -forming structure 3100 may be configured to seal to the patient’s lip superior. The patient interface 3000 may leave the patient’s mouth uncovered. This patient interface 3000 may deliver a supply of air or breathable gas to both nares of patient 1000 and not to the mouth. This type of patient interface may be identified as a nose-only mask.

[0207] One form of nose-only mask according to the present technology is what has traditionally been identified as a “nasal mask”, having a seal-forming structure 3100 configured to seal on the patient’s face around the nose and over the bridge of the nose. A nasal mask may be generally triangular in shape. In one form, the non- invasive patient interface 3000 comprises a seal-forming structure 3100 that forms a seal in use to an upper lip region (e.g. the lip superior), to the patient’s nose bridge or at least a portion of the nose ridge above the pronasale, and to the patient's face on each lateral side of the patient’s nose, for example proximate the patient’s nasolabial sulci. The patient interface 3000 shown in Fig. IB has this type of seal-forming structure 3100. This patient interface 3000 may deliver a supply of air or breathable gas to both nares of patient 1000 through a single orifice.

[0208] Another form of nose-only mask may seal around an inferior periphery of the patient’s nose without engaging the user’s nasal ridge. This type of patient interface 3000 may be identified as a “nasal cradle” mask and the seal-forming structure 3100 may be identified as a “nasal cradle cushion”, for example. The sealforming structure 3100 may be configured to seal around the patient’s nares at an inferior periphery of the patient’s nose including to an inferior and / or anterior surface of a pronasale region of the patient’s nose and to the patient’s nasal alae. The sealforming structure 3100 may seal to the patient’s lip superior. The shape of the sealforming structure 3100 may be configured to match or closely follow the underside of the patient’s nose and may not contact a nasal bridge region of the patient’s nose or any portion of the patient’s nose superior to the pronasale. In one form of nasal cradle cushion, the seal-forming structure 3100 comprises a bridge portion dividing the opening into two orifices, each of which, in use, supplies air or breathable gas to a respective one of the patient’s nares. The bridge portion may be configured to contact or seal against the patient’s columella in use. Alternatively, the seal-forming structureA2578192 12.0 323100 may comprise a single opening to provide a flow or air or breathable gas to both of the patient’s nares.

[0209] In some forms, a nose-only mask may comprise nasal pillows, described above.4.3.1.8 Nose and Mouth Masks

[0210] In one form, the patient interface 3000 comprises a seal-forming structure 3100 configured to seal around an entrance to the patient’s nasal airways and also around the patient’s mouth. The seal -forming structure 3100 may be configured to seal to the patient’s face proximate a chin region. This patient interface 3000 may deliver a supply of air or breathable gas to both nares and to the mouth of patient 1000. This type of patient interface may be identified as a nose and mouth mask.

[0211] One form of nose-and-mouth mask according to the present technology is what has traditionally been identified as a “full-face mask”, having a seal-forming structure 3100 configured to seal on the patient’s face around the nose, below the mouth and over the bridge of the nose. A nose-and-mouth mask may be generally triangular in shape. In one form the patient interface 3000 comprises a seal-forming structure 3100 that forms a seal in use to a patient’s chin-region (which may include the patient’s lip inferior and / or a region directly inferior to the lip inferior), to the patient’s nose bridge or at least a portion of the nose ridge superior to the pronasale, and to cheek regions of the patient's face. The patient interface 3000 shown in Fig. 1C is of this type. This patient interface 3000 may deliver a supply of air or breathable gas to both nares and mouth of patient 1000 through a single orifice. This type of sealforming structure 3100 may be referred to as a “nose-and-mouth cushion”.

[0212] In another form the patient interface 3000 comprises a seal-forming structure 3100 that forms a seal in use on a patient’s chin region (which may include the patient’s lip inferior and / or a region directly inferior to the lip inferior), to an inferior and / or an anterior surface of a pronasale portion of the patient’s nose, to the alae of the patient’s nose and to the patient’s face on each lateral side of the patient’s nose, for example proximate the nasolabial sulci. The seal-forming structure 3100 may also form a seal against a patient’s lip superior. A patient interface 3000 having this type of seal-forming structure may have a single opening configured to deliver a flow of air or breathable gas to both nares and mouth of a patient, may have an oral hole configured to provide air or breathable gas to the mouth and a nasal hole configured to provide air or breathable gas to the nares, or may have an oral hole forA2578192 12.0 33delivering air to the patient’s mouth and two nasal holes for delivering air to respective nares. This type of patient interface 3000 may have a nasal portion and an oral portion, the nasal portion sealing to the patient’s face at similar locations to a nasal cradle mask.

[0213] In a further form of nose and mouth mask, the patient interface 3000 may comprise a seal -forming structure 3100 having a nasal portion comprising nasal pillows and an oral portion configured to form a seal to the patient’s face around the patient’s mouth.

[0214] In some forms, the seal -forming structure 3100 may have a nasal portion that is separate and distinct from an oral portion. In other forms, a seal-forming structure 3100 may form a contiguous seal around the patient’s nose and mouth.

[0215] It is to be understood that the above examples of different forms of patient interface 3000 do not constitute an exhaustive list of possible configurations. In some forms a patient interface 3000 may comprise a combination of different features of the above described examples of nose-only and nose and mouth masks.4.3.2 Plenum chamber

[0216] The plenum chamber 3200 has a perimeter that is shaped to be complementary to the surface contour of the face of an average person in the region where a seal will form in use. In use, a marginal edge of the plenum chamber 3200 is positioned in close proximity to an adjacent surface of the face. Actual contact with the face is provided by the seal -forming structure 3100. The seal-forming structure 3100 may extend in use about the entire perimeter of the plenum chamber 3200. In some forms, the plenum chamber 3200 and the seal -forming structure 3100 are formed from a single homogeneous piece of material.

[0217] In certain forms of the present technology, the plenum chamber 3200 does not cover the eyes of the patient in use. In other words, the eyes are outside the pressurised volume defined by the plenum chamber. Such forms tend to be less obtrusive and / or more comfortable for the wearer, which can improve compliance with therapy.

[0218] In certain forms of the present technology, the plenum chamber 3200 is constructed from a transparent material, e.g. a transparent polycarbonate. The use of a transparent material can reduce the obtrusiveness of the patient interface, and helpA2578192 12.0 34improve compliance with therapy. The use of a transparent material can aid a clinician to observe how the patient interface is located and functioning.

[0219] 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 obtrusiveness of the patient interface, and help improve compliance with therapy.

[0220] In some forms, the plenum chamber 3200 is constructed from a rigid material such as polycarbonate. The rigid material may provide support to the sealforming structure.

[0221] In some forms, the plenum chamber 3200 is constructed from a flexible material (e.g., constructed from a soft, flexible, resilient material like silicone, textile, foam, etc.). For example, in examples then may be formed from a material which has a Young's modulus of 0.4 GPa or lower, for example foam. In some forms of the technology the plenum chamber 3200 may be made from a material having Young's modulus of 0.1 GPa or lower, for example rubber. In other forms of the technology the plenum chamber 3200 may be made from a material having a Young's modulus of 0.7MPa or less, for example between 0.7MPa and 0.3MPa. An example of such a material is silicone.4.3.3 Example cushion modules

[0222] One example of a cushion module 3150 of the present technology is shown in Figs. 7 - 7C. The cushion module 3150 comprises a rigid or semi-rigid chassis portion 3202, which forms, at least in part, the plenum chamber 3200, and a seal forming structure 3100 comprising a textile layer 3206.

[0223] In the illustrated example, the chassis portion 3202 is configured to be used with a patient interface that is configured as an oro-nasal mask. However, the present technology may also be suitable for use with a patient interface configured as a nasal cushion.

[0224] In certain forms of the present technology, the chassis or chassis portion 3202 of the plenum chamber 3200 is constructed from a transparent material. In other forms, the chassis portion 3202 may be constructed from a translucent material. The use of a transparent or translucent materials can reduce the obtrusiveness of the patient interface and help improve compliance with therapy. The use of a transparentA2578192 12.0 35material can aid a clinician to observe how the patient interface is located and functioning.

[0225] In some forms, the chassis portion 3202 of the plenum chamber 3200 is constructed from a rigid material such as polycarbonate (transparent, translucent or opaque), nylon, co-polyester, a blend of one or more of same, or other suitably rigid plastics material. The rigid material may provide support to the seal-forming structure. Some portions of the chassis portion 3202 may be formed such that some have greater or lesser thickness compared for other parts; for example, the portions of the chassis closest to the patient’s face may have a reduced thickness to confer some slight flexibility for greater comfort for the patient. Portions of the chassis portion 3202 which are further away from the face, and more central, may be thicker to better control the extent of flexure of these areas. The thickness of the rigid material may range from between 0.5 mm to 3 mm, although strict compliance with this range is not required.

[0226] In some forms, the chassis portion 3202 of the plenum chamber 3200 may be constructed from a semi-rigid material; this may be desired in order to provide some flexibility to the chassis. Suitable materials may include the likes of liquid silicone rubber or a thermoplastic elastomer. To provide some rigidity, and thus greater support for the seal-forming structure, the chassis portion 3202 may be configured to receive a frame 3280 composed of a rigid material such as polycarbonate (transparent, translucent or opaque), nylon, co-polyester, a blend of one or more of same, or other suitably rigid plastic materials. Examples of suitable frames 3280 are described further below.

[0227] As best seen in Figs. 7, 7B and 8D, the chassis portion 3202 is configured such that it is cup or bowl-shaped in profile, the interior or posterior side of the chassis defining an air chamber of the patient interface. The anterior side of the anterior wall 3204 of the chassis portion 3202 defines the exterior surface of the plenum chamber 3200.

[0228] In use, the air chamber receives the nose and mouth of the patient and it will be understood that the chassis portion 3202 will be dimensioned accordingly to ensure clearance about the nose and mouth of the patient in use. The chassis portion 3202 may be provided in a range of sizes; for example, its width, height, and depth may be arranged into small, mid, large, and extra-large embodiments to cater for different face sizes and shapes.A2578192 12.0 36

[0229] Centrally located to the chassis portion 3202 is an aperture (e.g. a plenum chamber inlet port 3254) configured to receive a decoupling structure (elbow) or the end of an air circuit 4170. However, in other examples, apertures may provided to one or both sides of the chassis 3202, rather than centrally, as per the example illustrated in the figures. In these other examples, the apertures 3254 may be configured with connectors or structures that in use receive the inferior ends of the tubes comprising the conduit headgear.

[0230] The chassis portion 3202 comprises or is provided with a flange 3208 about a portion of its perimeter. As illustrated, this flange 3208 extends in a plane inward towards the air chamber. This is preferred as it helps minimise the overall footprint of the plenum chamber 3200 on the patient’s face. However, in some examples not shown here, the flange 3208 may also extend, either wholly or partially, away from the air chamber. This may mean the entire flange 3208 is positioned exterior to the air chamber or alternatively, an outer portion of the flange 3208 is exterior of the air chamber and an inner portion extends inward towards the air chamber.

[0231] In the illustrated example, the flange 3208 is provided in regions that substantially correspond to the sides of the patient’s mouth, the patient’s cheeks, and to the sides of the patient’s nose, when the patient interface is in use. In the illustrated example, the width of the flange 3208 is substantially constant about the perimeter of the chassis portion 3202. In some examples, the width of the flange 3208 may be as little as 5 mm but in others, it could be 10 mm or more. Variances to these dimensions are envisaged. In other examples, there may be reductions or increases in the width of the flange 3208 for comfort and increased contact, and therefore sealing functionality; in these examples, the width of the flange 3208 may from between 5 mm to 10 mm, or lesser or greater if preferred.

[0232] In use, the posterior side of the flange 3208 receives and supports at least part of the seal-forming structure. In examples where the flange 3208 is formed from a relatively flexible material, the flange 3208 may be viewed as forming part of the seal forming structure in addition to, or alternatively to, the flange comprising part of the chassis portion. However, for simplicity, the flange is described below as forming part of the chassis.

[0233] As best seen in Fig. 8D, the chassis portion 3202 comprises an anterior wall 3204, a posterior wall 3209 which includes flange 3208, and a boundary 3232A2578192 12.0 37between the anterior and posterior walls 3204, 3209. The boundary 3232 is seen as the outer perimeter of the chassis portion 3202 when viewed from directly in front or behind, as in Figs 7A-7C.

[0234] The posterior wall 3209 may have substantially “C” shape in crosssection.

[0235] Returning to Fig. 7A, it will be seen that the chassis portion 3202 includes an opening or cutout 3205 on its upper or superior side. The presence of the opening 3205 provides clearance for the nose bridge of the patient’s face, this portion of the face being relatively sensitive. The flange 3208 is also absent in the region of the chassis which comprises the opening 3205.

[0236] As seen in Figs. 7, 7B and 7C, the textile layer 3206 is configured such that in use, the respective opening 3205 of the chassis is covered by a superior portion of the textile layer. It will be understood that the textile layer 3206 has an anterior side and posterior side; in use, the latter side contacts the patient’s face and such, forms the target seal-forming region.

[0237] In one example, the textile layer 3206 is cut from a sheet of textile material that is impermeable to air. It is particularly desirable that the textile material be relatively elastic, such that it can be stretched. In one example, this textile material may be a blend of nylon and spandex although it will be appreciated the textile material may be comprised of other materials, for example, a blend of synthetic materials derived from a polymer, or may also include or alternatively comprise some natural textiles, such as cotton or the like. The latter may be helpful for patients with allergies to synthetic materials. The anterior side of the textile layer 3206 is coated with a sheet or layer of a material such as silicone rubber or similar material. This helps with ensuring the textile layer 3206 is impermeable to air. In some examples, to further ensure the textile is impermeable to air, or to provide patient comfort, the posterior side of the textile layer 3206 may also be provided with a coating of silicone rubber or the like.

[0238] The textile layer 3206 may be cut from a single piece of material such that it is a unitary component, although in other examples the portion which covers the superior opening may be provided as a separate component.

[0239] Although the superior opening 3205 is covered, it is unsupported by the chassis portion, by virtue of the absence of the underlying chassis portion 3202 in this region. When a patient is wearing the patient interface incorporating the depictedA2578192 12.0 38plenum chamber 3200, the superior portion of the textile layer 3206 may be stretched across their nose bridge, applying tension to same and forming the sealing contact in this region of the face.

[0240] In one form of the technology the chassis portion 3202 may be relatively flexible. The chassis portion 3202 may be formed from an elastomer, for example silicone. In one example the chassis portion 3202 material may have a Shore A Durometer hardness of between 30 and 60.

[0241] Referring next to Fig. 7A in particular, the superior edges of the flange 3208 may be inferior to the nose bridge and the front of the nose of the patient. The flange 3208 may comprise sides of nose portions which are configured to engage the sides of the patient’s nose, in use. In examples, the sides of nose portions engage the nose at areas corresponding to the nasal bone (as opposed to cartilaginous portions of the nose) and provide a compliant sealing force. In examples, the sides of nose portions are configured to substantially avoid engagement of the sides of the patient’s nose corresponding to the patient’s greater alar cartilage and / or septum cartilage in order to prevent occlusion of the nose.

[0242] The chassis portion 3202 may hold the textile layer 3206 in place around the cheek and chin areas and may provide a level of compliance through bending of the main body of the chassis portion 3202 and / or the flange 3208. In one example the chassis portion 3202 may have a Shore A durometer of approximately 40, and may, for example, be made from LSR (Liquid Silicone Rubber).

[0243] The chassis portion 3202 may have a very low profile in the region near the patient’s nose. This configuration may avoid causing discomfort to the patient because the area over the patient’s nose is formed by the textile layer 3206 which spans the superior cutout. Even if the patient’s nose temporarily contacts the portion of the textile 3206 which spans the portion of the superior opening 3205 in the anterior wall 3204 of the chassis portion 3202, the patient will not feel significant discomfort since the textile layer 3206 is flexible, as is described further below. If the superior opening or cutout 3205 was not present, it would be necessary for the anterior wall of the chassis portion to be spaced further from the patient’s nose.

[0244] In some examples, the superior cutout 3205 may not extend to the anterior wall 3204 of the chassis portion 3202. Such examples may improve visibility and / or make mould tooling more efficient. Examples where the cutout 3205 does not extend to the anterior wall of the chassis portion 3202 may need to be configured to provideA2578192 12.0 39additional clearance between the chassis portion 3202 and the patient’s nose, since contact of the patient’s nose with the rigid or semi-rigid material of the anterior wall 3205 of the chassis portion 3202 may be unacceptably uncomfortable. In other examples, for example as shown in Figs. 21 and 22, the anterior wall 3204 may comprise a very thin resilient portion 3207 (e.g. between 0.25 mm - 0.6mm thick) having an outer perimeter which is substantially the same shape and location as the portion of the cutout 3205 in the anterior wall 3204 described above (e.g. as shown in Fig. 7 and 7A). The resilient portion 3207 may be integrally formed with (e.g. from the same material) the chassis portion 3202.

[0245] In such examples, the superior cutout 3205 and textile layer 3206 may not extend beyond the patient facing side of the cushion module 3150 (e.g. may not extend to the anterior wall 3204). The resilient portion 3207 may be sufficiently resilient or elastic to avoid discomfort if this region contacts the patient's nose.

[0246] The textile layer 3206 may be connected to the flange 3208, and may form the contact / sealing region with the patient’s face. In examples, a foam may be provided between the flange and the textile layer.

[0247] In examples, the textile layer 3206 is airtight and stretchable. The ability of the textile to stretch may reduce the tension across the nose bridge area and enables the cushion to fit a larger range of nose bridge shapes. In some examples the textile layer 3206 may be undermoulded by a very thin (e.g. <0.4mm) layer of elastomer for added support, or if the textile used is not independently air tight.

[0248] Referring next to Fig.7B in particular, the connection between the textile layer 3206 and the chassis portion 3202 and flange 3208 causes the textile layer to form a concave region which is configured to fit around the patient’s nose bridge. In one example the concave shape 3215 formed by the textile layer 3206 may have a width of between 8 mm and 20 mm (e.g. around 10 mm) and a depth between 5 mm and 20 mm (e.g. around 10 mm).

[0249] The width and depth of the concave region 3215 may be controlled by the shape of the textile layer 3206, when cut.

[0250] Areas in which the textile layer 3206 is not supported by a flange 3208 (e.g. where the textile layer 3206 spans the cutout 3205) may provide areas of increased stretch and softness, compared to areas in which the flange 3208 is present. Such areas may be used to reduce direct load and shear load on the sensitive area ofA2578192 12.0 40the nose bridge, where the thin skin and lack of underlying soft tissue is at risk of comfort issues and skin breakdown issues.

[0251] In some forms of the technology the textile layer 3206 extends around the entire periphery of flange 3208. However, in other examples the textile layer 3206 may be shaped such that it does not contact the patient's face in one or more areas, for example the chin, cheeks and / or sides of the nose. In such areas the flange 3208 may be configured as a sealing portion. This may be desirable, for example, to provide areas of higher friction which may assist with sealing and / or preventing the patient interface from slipping on the face.

[0252] In examples, the textile layer 3206 is connected to the flange 3208 by an overmoulding process.

[0253] Other cushion modules may be used with the frames of the present invention, for example some of those described in PCT publication WO2020 / 191463 (the contents of which are incorporated by reference).

[0254] In another form of the technology, shown in Figs. 20A and 20B, the chassis portion 3202 may not be made from a single material. Instead, a shell portion 3270 formed from a more rigid material, for example a polycarbonate, may be used to form at least a part, for example a central portion 3222, of the anterior wall 3204 of the chassis portion 3202. A more flexible material (for example an elastomer as described above) may be provided around at least a portion of the outer edge of the shell portion 3270. In examples, the more flexible material extends around substantially the entire outer edge of the shell 3270, apart from areas (if any) where the superior opening or cutout 3205 extends into the shell 3270.

[0255] The more flexible chassis portion material may be provided with (or connected to / formed with) a flange 3208 for mounting the textile layer 3206, as described above. In examples, the lateral and inferior walls of the plenum chamber 3200 are formed from the more flexible material (that is, in examples, the shell portion 3270 does not extend to these portions of the chassis portion).

[0256] The more flexible material may be overmoulded to the shell portion 3270. The shell portion 3270 may comprise features around its edge to assist with connection to the more flexible material.

[0257] Providing a shell portion 3270 may reduce the amount of more flexible material (e.g. elastomer) required to create the patient interface, which may result in weight and costs savings. It may also provide more support to the lateral and inferiorA2578192 12.0 41walls of the plenum chamber 3200, and may provide greater control of the deformed shape of those walls when the patient interface is in use. In examples, the shell portion 3270 may comprise tube connection geometry and / or frame connection geometry.

[0258] Referring next to Fig. 22 and 23, in examples the chassis portion 3202 may comprise one or more grooves or channels 3240 into which a frame 3280 or frame portion may be received. These channels 3240 may help to guide the frame 3280 or frame portion into the correct position during assembly to the cushion module 3150. The channels or grooves 3240 may also reduce the extent to which the frame 3280 or frame portion protrudes from the surface of the chassis portion 3202, which may improve the aesthetics of the patient interface 3100 and / or may reduce the likelihood of the frame 3280 or frame portion catching on bed clothes and the like.

[0259] Assembly features / geometry may be provided within the channels 3240 for engaging the frame / frame portion.4.3.4 Cushion modules with stiffening portions

[0260] Referring next to Figs. 14A-19, in some forms of the technology chassis portion 3202 which is made from a semi-rigid material (e.g. as described above) may comprise stiffening portions 3234. The stiffening portions 3234 may be made from a rigid or semi-rigid material, or at least a material which is more rigid than the material from which the remainder of the chassis portion 3202 is formed.

[0261] The stiffening portions 3234 may provide support to the sides of the chassis portion 3202 and prevent collapse of the shape of the chassis portion 3202 under load through headgear tension and mask pressure (see Fig. 8D).

[0262] The stiffening portions 3234 may provide a more rigid base for the “C” shaped posterior side of the chassis portion 3202 (see Fig. 8D). In examples, the central part of the chassis portion 3202 (e.g. between the stiffening portions 3234) may remain largely flexible, thereby allowing for some decoupling of side loading forces from the seal forming portion. The stiffening portions 3234 may extend all the way down each side of the chassis portion 3202, or may only run part-way down the sides, depending how much rigidity is intended to be provided to the side of the chassis portion 3202. The width of the stiffening portions 3234 may be adjusted to provide more or less rigid support to the wall of the chassis portion 3202.A2578192 12.0 42

[0263] Referring next to Figs. 14A-17, in many examples the stiffening portions 3234 are provided to the anterior wall 3204 of the chassis portion 3202. The stiffening portions 3234 are typically provided adjacent the boundary 3232 between the anterior and posterior walls 3204, 3209 of the chassis portion 3202. The stiffening portions may be orientated substantially parallel to the boundary 3202. Typically, the stiffening portions 3234 are higher than they are wide, e.g. in a height to width ratio of at least 2: 1, for example between 2: 1 and 10: 1 or more.

[0264] Referring next to Figs. 14A and 14B, in one example stiffening portions 3234 are provided to the anterior side of the chassis portion 3202, adjacent the boundary 3232 between the anterior and posterior walls 3204, 3209. In the example shown in these figures the stiffening portions 3234 extend from the upper edge of the chassis portion 3202 to a position slightly inferior of the inlet port 3600. The stiffening portions 3234 are relatively narrow (e.g. around 6: 1 heightwidth) and follow the shape of the boundary 3232 between the anterior and posterior walls 3204, 3209.

[0265] Referring next to Fig. 15, in another example stiffening portions 3234 are provided to the anterior wall 3204 of the chassis portion 3202, adjacent the boundary 3232 between the anterior and posterior sides. The stiffening portions 3234 are relatively narrow (e.g. around 4:1 heightwidth). In the example shown in this figure the stiffening portions 3234 extend along substantially the middle third of the height of the chassis portion 3202.

[0266] Referring next to Fig. 16, in another example stiffening portions 3234 are provided to the anterior wall 3204 of the chassis portion 3202, adjacent the boundary 3232 between the anterior and posterior walls 3204, 3209. The stiffening portions 3234 extend from around the upper quarter of the height of the chassis portion 3202 to the lower quarter of the height of the chassis portion 3202. The stiffening portions 3234 are around one half as wide as they are high.

[0267] Referring next to Fig. 17, in another example stiffening portions 3234 are provided to the anterior wall 3204 of the chassis portion 3202, adjacent the boundary 3232 between the anterior and posterior walls 3204, 3209. The stiffening portions 3234 are relatively narrow (e.g. around 12: 1 height width) and follow the shape of theA2578192 12.0 43boundary 3232 between the anterior and posterior walls 3204, 3209. The stiffening portions 3234 extends from a superior edge of the chassis portion 3202 to an inferior edge.

[0268] In examples, the stiffening portions 3234 may be constructed of a rigid material such as polycarbonate. The stiffening portions 3234 may be integrally moulded into the cushion in an overmould process, or they may affixed after moulding. In such examples, the stiffening portions 3234 may be between 1mm and 3mm thick.

[0269] In other examples the stiffening portions 3234 may be constructed from a semi-rigid material such as polyester (e.g. Hytrel) so they have a predetermined amount of flexibility that is somewhat less than the more flexible material of the chassis portion 3202 (e.g. silicone rubber). Such stiffening portions 3234 may also be overmoulded or affixed post moulding.

[0270] In other examples, the stiffening portions 3234 may be constructed of a silicone rubber that is a stiffer grade than the material of the remainder of the chassis portion 3202. For example, the stiffening portions 3234 may be made of silicone rubber that is 60-90 Shore A hardness. They may be added to the chassis portion 3202 in two component (“2K”) moulding process. Examples of stiffening portions 3234 made from silicone rubber may be between 1mm and 4mm thick.

[0271] Utilising stiffening portions 3234 in the chassis portion 3202 may allow the size of the frame 3280 to be reduced (for example as shown in Fig. 18), as some of the rigidity function of the frame 3280 may be achieved by the stiffening portions 3234. A smaller frame 3280 may be less costly, may improve aesthetics and / or may and make it easier to provide a single size of frame which fits several sizes of cushion.

[0272] In examples, the stiffening portions 3234 may be entirely embedded in the wall of the chassis portion 3202 such that none of the surface of the stiffening portion 3234 is exposed. However, in some examples some parts of the external wall of the stiffening portion 3234 may be exposed to allow for positioning during moulding or to provide areas where assembly geometry 3292 for the frame attachment may be located (see Fig. 19).A2578192 12.0 44

[0273] Provision of stiffening portions 3234 may be particularly useful where the chassis portion 3202 is made from a relatively flexible material such as silicone.

[0274] In other examples (e.g. as shown in Fig. 23), instead of stiffening portions 3234 made from a different material to the chassis portion 3202, in some examples the chassis portion 3202 may comprise thickened portions 3236 to reinforce the chassis portion 3202 against bending. In examples, the thickened portions 3236 may be positioned to be immediately superior to and / or immediately inferior of the side portions of the frame 3282 when the frame 3280 is assembled to the cushion module 3150. This may be particularly useful for examples which have a relatively small frame 3280, e.g. as with the example shown in Fig. 18.

[0275] The thickened portions 3236 may comprise curved surfaces which are configured to resist bending in a desired direction.

[0276] In examples, the thickened portions 3236 may be 2.5 mm - 5 mm thick. The height and thickness of the thickened portions 3236 may vary, e.g. depending on the height of the particular cushion module 3150. Thickened portions 3236 may only be provided superior to or inferior of the frame 3280 as needed to provide desired resistance to bending.

[0277] The use of such thickened portions 3236 may allow different size cushion modules 3150 to be used with the same size frame 3280.4.3.5 Positioning and stabilising structure

[0278] The seal-forming structure 3100 of the patient interface 3000 of the present technology may be held in sealing position in use by a positioning and stabilising structure 3300. The positioning and stabilising structure 3300 may comprise and function as “headgear” since it engages the patient’s head in order to hold the patient interface 3000 in a sealing position. Examples of a positioning and stabilising structure may be shown in Figs. 3 A, 3A-1 and in particular Fig. 4.

[0279] In one form the positioning and stabilising structure 3300 provides a retention force at least sufficient to overcome the effect of the positive pressure in the plenum chamber 3200 to lift off the face (i.e., Fpienum).A2578192 12.0 45

[0280] In one form the positioning and stabilising structure 3300 provides a retention force to overcome the effect of the gravitational force on the patient interface 3000.

[0281] With continued reference to Fig. 3A-1, the positioning and stabilising structure 3300 provides a force Fpss that assists in maintaining the plenum chamber 3200 in the sealing position on the patient’s face. The positioning and stabilising force Fpss may be the resultant force from the various forces of the different elements of the positioning and stabilising structure 3300. For example, headgear straps may individually provide a strap force Fstrap in order to hold the seal -forming structure 3100 against the patient’ s face. The force Fstrap may also be directed at least partially in the superior direction in order to overcome the gravitational force Fg. The gravitational force Fgmay be specifically shown for the seal-forming structure 3100 and the plenum chamber 3200, but gravity would act on the entirely of the patient interface 3000 (i.e., in the same direction as the illustrated gravitational force Fg).

[0282] The gravitational force Fgmay be opposed by a frictional force Ff, which may act in a direction directly opposite of the gravitational force Fg. As gravity pulls the seal -forming structure 3100 and the plenum chamber 3200 in the inferior direction (as viewed in Fig. 3A-1), the frictional force Ff would act in the superior direction (e.g., against a patient’s face). For example, the patient may experience the frictional force Ff against his lip superior (and / or other surfaces of the patient’s face in contact with the seal-forming structure 3100) in order to oppose the motion in the inferior direction (which may help to stabilising the cushion in place). Although the frictional force Ff is shown specifically opposing the gravitational force Fgof the seal -forming structure 3100 and the plenum chamber 3200, components of an overall frictional force (not shown) would also oppose the gravitational force Fgassociated with the positioning and stabilising structure 3300 and any other portions of the patient interface 3000. A force of friction can act along any place where the patient interface 3000 contacts the patient’s skin (or hair). The frictional force Ff extends in the opposite direction of the gravitational force Fgand along the patient’s skin (or hair). In some forms the gravitiational force Fgmay also be countered by vertical components of the reaction force from the patient’s face acting on the seal -forming structure 3100, for example at the nose ridge and chin regions of the patient’s face, for example.A2578192 12.0 46

[0283] In one form the positioning and stabilising structure 3300 provides a retention force as a safety margin to overcome the potential effect of disrupting forces on the patient interface 3000, such as from tube drag, or accidental interference with the patient interface.

[0284] In one form of the present technology, a positioning and stabilising structure 3300 is provided that is configured in a manner consistent with being worn by a patient while sleeping. In one example the positioning and stabilising structure 3300 has a low profile, 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 having a rectangular cross-section. In one example the positioning and stabilising structure 3300 comprises at least one flat strap.

[0285] In one form of the present technology, a positioning and stabilising structure 3300 is provided that is configured so as not to be too large and bulky to prevent the patient from lying in a supine sleeping position with a back region of the patient’s head on a pillow.

[0286] In one form of the present technology, a positioning and stabilising structure 3300 is provided that is configured so as not to be too large and bulky to prevent the patient from lying in a side sleeping position with a side region of the patient’s head on a pillow.

[0287] In one form of the present technology, a positioning and stabilising structure 3300 is provided with a decoupling portion located between an anterior portion of the positioning and stabilising structure 3300, and a posterior portion of the positioning and stabilising structure 3300. The decoupling portion does not resist compression and may be, e.g. a flexible or floppy strap. The decoupling portion is constructed and arranged so that when the patient lies with their head on a pillow, the presence of the decoupling portion prevents a force on the posterior portion from being transmitted along the positioning and stabilising structure 3300 and disrupting the seal.

[0288] In one form of the present technology, a positioning and stabilising structure 3300 comprises a strap constructed from a laminate of a fabric patientcontacting layer, a foam inner layer and a fabric outer layer. In one form, the foam is porous to allow moisture, (e.g., sweat), to pass through the strap. In one form, the fabric outer layer comprises loop material to engage with a hook material portion.A2578192 12.0 47

[0289] In certain forms of the present technology, a positioning and stabilising structure 3300 comprises a strap that is extensible, e.g. resiliently extensible. For example the strap may be configured in use to be in tension, and to direct a force to draw a seal-forming structure into sealing contact with a portion of a patient’s face. In an example the strap may be configured as a tie.

[0290] In one form of the present 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 an inferior edge thereof passes superior to an otobasion superior of the patient’s head and overlays a portion of a parietal bone without overlaying the occipital bone.

[0291] In one form of the present technology suitable for a nasal-only mask or for a full-face mask, the positioning and stabilising structure includes a second tie, the second tie being constructed and arranged so that in use at least a portion of a superior edge thereof passes inferior to an otobasion inferior of the patient’s head and overlays or lies inferior to the occipital bone of the patient’s head.

[0292] In one form of the present technology suitable for a nasal-only mask or for a full-face mask, the positioning and stabilising structure includes a third tie that is constructed and arranged to interconnect the first tie and the second tie to reduce a tendency of the first tie and the second tie to move apart from one another.

[0293] In certain forms of the present technology, a positioning and stabilising structure 3300 comprises a strap that is bendable and e.g. non-rigid. An advantage of this aspect is that the strap is more comfortable for a patient to lie upon while the patient is sleeping.

[0294] In certain forms of the present technology, a positioning and stabilising structure 3300 comprises a strap constructed to be breathable to allow moisture vapour to be transmitted through the strap,

[0295] In certain forms of the present technology, a system is provided comprising more than one positioning and stabilising structure 3300, each being configured to provide a retaining force to correspond to a different size and / or shape range. For example the system may comprise one form of positioning and stabilising structure 3300 suitable for a large sized head, but not a small sized head, and another, suitable for a small sized head, but not a large sized head.A2578192 12.0 484.3.5.1 Headgear straps

[0296] In some forms, the positioning and stabilising structure 3300 may include headgear 3302 with at least one strap which may be worn by the patient in order to assist in properly orienting the seal -forming structure 3100 against the patient’s face (e.g., in order to limit or prevent leaks).

[0297] As described above, some forms of the headgear 3302 may be constructed from a textile material, which may be comfortable against the patient’s skin. The textile may be flexible in order to conform to a variety of facial contours. Although the textile may include rigidisers along a selected length, which may limit bending, flexing, and / or stretching of the headgear 3302.

[0298] In certain forms, the headgear 3302 may be at least partially extensible. For example, the headgear 3302 may include elastic, or a similar extensible material. For example, the entire headgear 3302 may be extensible or selected portions may be extensible (or more extensible than surrounding portions). This may allow the headgear 3302 to stretch while under tension, which may assist in providing a sealing force for the seal -forming structure 3100.

[0299] The patient interfaces of the present invention typically use four-point connection headgear, as described further below.4.3.5.1.1 Four-point connection

[0300] As shown in Fig. 4, some forms of the headgear 3302-1 may be a four- point connection headgear. This means that the headgear 3302-1 may connect to four separate places on the plenum chamber 3200, on a frame connected to the plenum chamber 3200, and / or on arms connected to the plenum chamber 3200. The headgear 3302-1 may include four different straps providing a tensile force to help maintain the seal-forming structure 3100 in a sealing position. The positioning and stabilising structure 3300 of Fig. 3 A may also be considered a four-point connection headgear.

[0301] In some forms, the headgear 3302-1 may include inferior straps 3304-1, which may connect to an inferior portion of the cushion or frame. The inferior straps 3304-1 may extend along the patient’s cheek toward a posterior region of the patient’s head. For example, the inferior straps 3304-1 may overlay the masseter muscle on either side of the patient’s face. The inferior straps 3304-1 may therefore contact the patient’s head below the patient’s ears. The inferior straps 3304-1 may meet at the posterior of the patient’s head, and may overlay the occipital bone and / or the trapezius muscle.A2578192 12.0 49

[0302] The headgear 3302-1 may also include superior straps 3305-1, which may overlay the temporal bones, parietal bone, and / or occipital bone.

[0303] A rear strap 3307-1 may extend between the superior straps 3305-1 and between the inferior straps 3304-1. The inferior and superior straps 3304-1, 3305-1 on a given side (e.g., left or right) may also be connected to the rear strap 3307-1 adjacent to one another. The height of the rear strap 3307-1 may therefore be approximately the combined height of the inferior and superior strap 3304-1, 3305-1. The rear strap 3307-1 may overlay the occipital bone and / or the pariental bone in use. This may allow the rear strap 3307-1 to assist in anchoring the headgear 3302-1 to the patient’s head.

[0304] In the illustrated example, the headgear 3302-1 may be formed with a substantially X-shape. The inferior and superior straps 3304-1, 3305-1 may be connected to a rear strap 3307-1 using stitching, ultrasonic welding, or any similar process.

[0305] In some forms, the inferior straps 3304-1 are connected to a magnetic member 3306-1. For example, each inferior straps 3304-1 may be threaded through a magnetic member 3306-1, so that a length of each inferior strap 3304-1 may be adjusted. The magnetic members 3306-1 may removably connect to the magnets 3370-1 (described below), so that the inferior straps 3304-1 may be disconnected from the plenum chamber or frame, but the length of the inferior straps 3304-1 may not be affected.

[0306] In some forms, the headgear 3302-1 may be used only with a nose and mouth cushion (e.g., because the nose-only cushion does not have four connection points).4.3.6 Frames

[0307] Example frames of the present invention are described further below.4.3.6.1 One part frames

[0308] Referring next to Figs. 8-8D, a patient interface according to one form of the technology comprises a cushion module 3150, such as that described above with reference to Figs. 7-7C or 14A-19, connected to a frame 3280.

[0309] The frame 3280 comprises first and second side portions 3282. An upper portion 3284 of the frame connects the superior ends 3286 of the first and second side portions 3282, and a lower portion 3288 connects the inferior ends 3290 of the sideA2578192 12.0 50portions 3282. In this example, the frame 3280 is configured to extend around an outer perimeter of the chassis portion 3202 on the anterior wall 3204 of the chassis portion. The side portions of the frame are positioned adjacent the boundary 3232 between the anterior and posterior walls of the chassis portion, as best seen in Figs.8 and 8B.

[0310] In examples, the frame 3280 is formed from a moulded or printed (e.g. additive manufacture) material. The material may be rigid (e.g. polycarbonate) or semi flexible (e.g. a polyester such as Hytrel™ or polypropylene). In one form of the technology the frame 3280 is moulded (or printed) as a single piece. In other forms the upper and / or lower portions 3284, 3288 may be made from a different material to the side portions 3282 (and / or from each other). In one example one or both of the upper and lower portions 3284, 3288 are overmoulded to the side portions 3282 and are made from a different material to the side portions.

[0311] The frame 3280 is configured to provide a structural support around the flexible chassis portion 3202 in order to allow it to maintain a required shape under load. As is described further below, the thickness of the frame 3280 may be varied in different areas of the frame in order to vary the amount of flexibility in local sections. Generally, the thickness is between 1 mm and 4 mm.

[0312] The side portions 3282 of the frame 3280 provide a connection between the headgear 3300 and the cushion module 3150.

[0313] The side portions 3282 in the example shown in Figs. 8 to 8D extend up the lateral sides of the chassis portion 3202. The inferior ends 3290 overlie the patient’s cheeks, below the mouth. The superior ends 3286 are located near or beside the patient’s nose. This configuration may provide maximum support to the anterior wall 3204 of the chassis portion 3202. In other embodiments (for example, as shown in Figs. 9 and 10) the side portions 3282 may not extend up as high as beside the nose. This may provide less underlying support to the regions of the chassis portion 3202 beside the nose, but may improve comfort by removing some rigidity from the patient interface and allowing the chassis portion 3202 wall to flex more.

[0314] The side portions 3282 may be designed to be substantially rigid components. In examples, the side portions 3282 are between 1mm and 4mm thick, depending on the material from which they are formed. A small amount of flexibility may be introduced through material selection to facilitate increased cushion comfort.A2578192 12.0 51

[0315] The side portions 3282 may be connected to the chassis portion 3202 at at least one connection point 3292 per side portion (see e.g. Fig. 8). In examples, the connection point 3292 may be configured such that the frame side portion 3282 is in contact with the chassis portion 3202 along substantially its entire length. This may prevent or limit relative movement between the side portions 3282 and the chassis portion 3202.

[0316] In the example shown in Figs. 8-8D, the connection points 3292 comprise holes 3294 in the frame 3280 to which projecting portions 3296 provided to the chassis portion 3202 are engaged, e.g. in a friction fit. A similar connection point 3292 is used in ResMed’s F40™ full face patient interface. However, the connection between the frame 3280 and the chassis portion 3202 may be achieved in other ways - for example the push-through geometry being reversed (i.e. projecting portions 3296 provided to the frame 3280 which push into or through recesses or apertures 3294 in the chassis portion 3202). In other forms of the technology (e.g. as shown in Figs. 9 and 10), snap fit geometry may be provided to an exterior surface of the anterior wall of the chassis portion, and may engage with complementary geometry provided to the posterior of patient facing side of the frame.

[0317] Fig. 8D shows the force Fplenum exerted on the patient interface by the face of the patient and the gas pressure within the plenum chamber. The force Fstrap exerted by a strap of the positioning and stabilising structure is also shown. Force Fr is the component of force Fstrap which opposes Fplenum.

[0318] In the example shown in Figs. 8-8D, each frame side portion 3282 comprises two connection points 3292. The superior connection points 3292 are located near the sides of the nose and the inferior connection points 3292 are provided just above lower arms 3324 (described further below). The use of these spaced apart connection points 3292 ensures that the chassis portion 3202 anterior wall and the frame side portion 3282 remain closely located and minimises the movement between the two. More connection points 3292 may be added to further increase the connection stability, if required, or fewer may be provided.

[0319] The upper portion 3284 of the frame 3280 connects the two side portions 3282. In the example shown in Figs. 8-8D, the upper portion 3284 extends underneath the cutout 3205 of the chassis portion 3202 at the nose bridge so as not to create a rigid contact point in the area of the cushion module 3150 that is configured to provide soft comfortable contact with the nose bridge. As best seen in Fig. 8, theA2578192 12.0 52upper portion 3284 of the frame may be configured to extend around a perimeter of the cutout 3205. The upper portion 3284 may therefore form a substantially “U” shape when viewed from in front. As best seen in Fig. 8C, the upper portion 3284 may also have a substantially “U” shaped profile when viewed from above.

[0320] The height and width of the upper portion 3284 may be configured to provide rigidity and flex as needed. Maximum rigidity will provide maximum support for the flexible cushion module 3150. However, configuring the upper portion 3284 to be somewhat flexible allows the cushion module 3150 to flex under side loads (e.g. from bedding) and reduces the chance of the seal forming structure shifting (thereby causing leak) when the cushion module 3150 is exposed to such loads. In one form of the technology the upper portion 3284 has cross-section dimensions of 3 mm x 3 mm.

[0321] In another example, the upper portion 3284 may be overmoulded to the side portions 3282 and may be constructed from a different material to the side portions 3282. This may allow for increased flexibility of the upper portion 3284 and / or may provide aesthetic improvements.

[0322] In some examples the upper portion 3284 may connect lower down on the side portions 3282 of the frame 3280 (e.g. below the superior ends 3286). In such examples the curvature of the upper portion 3284 (when viewed from in front) may be reduced (e.g. the U-shape may be flattened) for increased rigidity or for aesthetic improvements. In examples the upper portion 3284 may be substantially straight when viewed from in front (e.g. as seen in Figs. 9 and 10). In some examples, the superior end of the side portions 3282 of the frame may extend above the upper portion 3284, that is, that upper portion 3284 may be connected to the side portions 3282 between their superior and inferior ends, but generally toward the superior ends 3286.

[0323] In examples the lower portion 3288 of the frame may be moulded with the side portions 3282 (and optionally the upper portion 3284), but in other examples it may be overmoulded in a different material (e.g. to create the desired flexibility). The lower portion 3288 may provide some underlying support for the chassis portion across the chin to allow load to transfer from the tension of the headgear to the patient’s face.

[0324] In examples, the frame 3280 comprises a pair of upper arms 3298. The upper arms 3298 are provided with upper headgear connector means 3322. The upper arms 3298 provide a connection between the upper headgear straps 3305-1 (not shown in Figs. 8 - 13) and the frame 3280, while ensuring that upper headgear strapA2578192 12.0 533305-1 substantially clears the eyes of the patient. In the examples shown in Figs. 8 to 13, the embodiment the upper arms 3298 have substantially the same shape as those provided to ResMed’s F20™ full face mask. In the examples shown the upper headgear connector means 3322 of the upper arms 3298 comprise slots for receiving a loop of a headgear strap, but any other suitable form of headgear connector may be used. In examples, headgear such as that shown in Fig. 4 may be used with the frames of the present technology.

[0325] The upper arms 3298 may be moulded with the side portions 3282 of the frame, but in some examples may comprise separate components that are connected to (e.g. snapped fit, welded on) the side portions 3282 if a different flexibility or aesthetic profile is required for the arms.

[0326] In some forms of the technology the upper arms 3298 may comprise a hinge formation at the point they contact or are connected to the side portion 3282 of the frame. This may allow for controlled flexibility. In other examples the connection may be substantially rigid to allow arm loads to be transferred more directly to the cushion module 3150. Rigidly attaching the arms 3298 to the frame side portions 3282 may encourage flexing in the upper portion 3284 of the frame rather than in the area of the arm to side frame portion connection.

[0327] Referring next to Fig. 10, in some examples material may be removed from areas 3299 of the upper arms 3298 to increase the flexibility of the arms 3298 in that area. The upper arms 3298 may be thinned (or have thinned portions) in such areas 3299, or apertures may extend through the upper arms in these areas, as shown in Fig. 10. These areas 3299, or the entire arms 3298, may be covered in a textile (e.g. a sleeve), for example as shown in Fig. 8.

[0328] In some forms of the technology (e.g. as shown in Figs.8-8D and 11-1 IB, 12) the frame 3280 comprises lower arms 3324. The lower arms 3324 provide an attachment point for the lower headgear straps 3304-1 to the frame 3280.

[0329] The lower arms 3324 may be moulded together with the side portions 3282 or they may be connected to the side portions 3282 by means such as snap fit or welding if a different material is required, e.g. for flexibility or aesthetics.

[0330] The lower arms 3324 are provided with lower headgear connectors 3326. In the embodiments shown the lower headgear connectors 3326 comprise magnetic connectors, e.g. used in ResMed’s F20™ full face mask, but any other suitable form of headgear connector may be used.A2578192 12.0 54

[0331] Referring next to Figs. 9 and 10, in examples the upper portion 3284 of the frame extends substantially midway between the patient’s upper lip and the base of their nose. The upper portion 3284 may be substantially straight, or only slightly curved upward at the lateral ends (when viewed from in front). The upper portion 3284 may connect to the superior ends 3286 of the side portions 3282 of the frame. In these examples, the side portions 3282 of the frame do not extend as far up the chassis portion 3202 as the example shown in Figs. 8-8D. In examples, the upper arms 3298 also extend from the superior ends 3286 of the side portions 3282, such that the upper portion 3284 of the frame is substantially continuous with the upper arms 3298.

[0332] In the examples shown in Figs. 9 and 10 lower headgear connectors 3326 are provided to the side portions 3282 of the frame, rather than to lower arms 3324, although lower arms 3324 may be provided to these examples.4.3.6.1 Two part frames

[0333] Referring next to Figs. 11-12, in some forms of the technology the frame 3280 comprises the frame side portions 3282, but not the upper or lower portions. The frame side portions 3282 are configured for connection to the chassis portion 3202 (e.g. by a snap fit connection) but are not connected to each other (except indirectly via the chassis portion).

[0334] Each side portion 3282 of the frame may be moulded from a single material, preferably a material having a required flexibility (e.g. nylon or Hytrel™).

[0335] Upper and (optionally) lower arms 3298, 3324 may be provided. The upper and / or lower arms may be hinged, as with the examples described above. The upper and lower arms 3298, 3324 comprise headgear connectors, as described above. If no lower arms 3324 are provided, headgear connectors may be provided directly to the side portions 3282 of the frame (e.g at the inferior ends 3290).

[0336] Two part frames may assist in reducing the bulk at the front of the mask, leaving it clear and open. The connector port 3600 may be provided to the centre of the cushion chassis 3202. Some examples may be packed flat during shipping.

[0337] In one embodiment, a connection (e.g. snap fit) between the chassis portion 3202 and frame side portions 3282 creates no airpath, such that no leak passesA2578192 12.0 55through the joint - e.g. the snap geometry may be entirely on the external surface of the chassis portion 3202.

[0338] In another embodiment, a predetermined air flow may be permitted through the connection between the chassis portion 3202 and the frame side portions 3282, to provide (partial or full) mask vent flow. The flow may be achieved by clearances between the frame portions 3282 and chassis portion 3202 or by air holes through the frame portion 3282. The frame side portion 3282 may also be assembled with a diffuser material (e.g. felt) to reduce the noise level of the vented air, for example as shown in Fig. 12. The connector and venting geometry may be visually hidden under the frame portions.4.3.6.3 Centre mount frame

[0339] Referring next to Fig. 13, in one form of the technology a frame 3280 may be provided which partially covers the central part of the chassis portion 3202.

[0340] The frame 3280 may comprise a pair of upper arms 3298 and a pair of lower arms 3324, the upper and lower arms each connected to a central portion 3327. The central portion 3327 may comprise an aperture to allow an air circuit connector (e.g. an elbow 3610, a swivel or the like) to extend through the central portion 3327 and connect to a connection port 3600 of the cushion module 3150.

[0341] In examples, the frame 3280 is centrally mounted around the connection port 3600, or may have underlying snap fit geometry to the sides of the connection port 3600. The frame 3280 may be moulded from a single material. The material may allow a degree of flexibility to allow the upper and lower frame arms 3298, 3324 to bend or hinge to fit different head sizes. Flexibility in the arms may be aided by one or more hinge points created by thin wall sections, as described above. The ends of the frame arms comprise headgear connection means 3322 as described above, for example slots which allow for connection to hooks or for strap loops to pass through, magnetic or nonmagnetic clip connections. The position of the arms may be raised or lowered to provide appropriate headgear vectors for a proper seal.

[0342] The frame 3280 may contain venting features / geometry around the connection port 3600, such as air holes or a captured diffuser material.

[0343] Frames of this type may allow for rapid manufacturing processes, for example by 3D printing.A2578192 12.0 56

[0344] The frame 3280 may contain features for an elbow or tube connector component to assemble to, for example ones similar to Resmed’s F20™ full face mask.4.3.6.4 Frame with separately formed arms

[0345] Fig. 24 shows a patient interface 3000 according to another example of the present technology. In this example, the patient interface 3000 comprises a plenum chamber 3200 pressurisable to a therapeutic pressure of at least 4 cmH20 above ambient air pressure, the plenum chamber 3200 including at least one plenum chamber inlet port sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient. The patient interface 3000 also comprises a sealforming structure 3100 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 3100 having a hole therein such that the flow of air at said therapeutic pressure is delivered to at least an entrance to the patient’s nares. The seal-forming structure 3100 is constructed and arranged to maintain said therapeutic pressure in the plenum chamber throughout the patient’s respiratory cycle in use. In the example shown in Fig. 24, the seal-forming structure 3100 is structured to seal around the patient’s nose and mouth including to the patients nasal ridge, the patient’s cheeks and inferior to the patient’s lip inferior. In other examples the seal-forming structure 3100 may be configured to seal differently, such as around the patient’s nose only (e.g. in the form of a nasal-only patient interface 3000), around the patient’s nose and mouth but under the patient’s nose instead of over the patient’s nasal ridge, or around the patient’s nose but under the nose instead of over the patient’s nasal ridge. In some examples, the seal -forming structure 3100 is formed from an elastomeric material such as silicone or TPE. In other examples the seal -forming structure 3100 may be formed at least partially from a textile material, such as a textile material having an air-impermeable backing.

[0346] The patient interface 3000 further comprises a positioning and stabilising structure 3300 to provide a force to hold the seal-forming structure 3100 in a therapeutically effective position on the patient’s head. In this example the positioning and stabilising structure 3300 comprises a frame 3820 and headgear 3302 connected to the frame 3820, as shown in Fig. 24. The headgear 3302 may comprise a pluralityA2578192 12.0 57of straps or strap portions, which may be constructed according to any of the embodiments described herein, including any combination thereof.

[0347] As shown in Fig. 24, the headgear 3302 of the positioning and stabilising structure 3300 may comprise a pair of superior strap portions 3301 (similar to superior straps 3305-1 of Fig. 4) configured to connect to the superior headgear connectors 3322 and a pair of inferior strap portions 3303 (similar to inferior straps 3304-1 of Fig. 4) configured to connect to the inferior headgear connectors 3326. The headgear 3302 may further comprise a crown strap portion 3304 configured to engage superior and posterior surfaces of the patient’s head, and may further comprise a neck pad 3305 at a junction between the inferior strap portions 3303 and the crown strap portion 3304.

[0348] The superior headgear connectors 3322 in this example comprise slots. Each of the superior strap portions 3301 may connect to the superior headgear connectors 3322 by passing through the slots and being secured back to itself, for example with a hook-and-loop connection. The superior strap portions 3301 may comprise pull tabs. The inferior headgear connectors 3326 may each comprise a magnet configured to be engaged a corresponding clip on a respective one of the inferior strap portions 3303, the clip having a magnet or ferromagnetic material to engage the magnet of the inferior headgear connector 3326. In other examples the clip on the inferior strap portion 3303 may comprise a magnet and the inferior headgear connector 3326 may comprise a ferromagnetic material to attract the magnet. In some examples, the cushion module 3150 comprises a pair of cushion module connection portions (not shown) each provided on a respective lateral side of the cushion module 3150 and the frame 3280 comprises a pair of frame connection portions 3961. Each frame connection portion 3961 is structured to releasably connect to a respective one of the cushion module connections portions.

[0349] The frame connection portions 3961 may be located between a respective one of the superior arms 3298 and a respective one of the inferior arms 3324.

[0350] Turning to Figs. 24A-24C, in this example the frame 3820 comprises a pair of arm portions 3904, each arm portion 3904 comprising a respective one of the pair of superior arms 3298 and a respective one of the pair of inferior arms 3324. InA2578192 12.0 58this example, each arm portion 3904 is constructed separately to a central portion 3901

[0351] of the frame 3820 (similar to central portion 3327) and is attached to the central portion 3901 of the frame 3820. The arm portions 3904 are attached on a respective lateral side thereof.. In this example, when each arm portion 3904 of the frame 3820 is attached to the central portion 3901 of the frame 3820, each arm portion 3904 surrounds a respective one of the frame connection portions 3961.

[0352] With reference to Fig. 24C in particular, in this example the central portion 3901 of the frame 3820 comprises a pair of lateral portions 3907, and each arm portion 3904 is attached to a respective one of the lateral portions 3907. The lateral portions 3907 also define the frame connection portions 3961. As shown in Fig. 24A, each arm portion 3904 comprises a medial portion 3906 from which the respective superior arm 3298 and inferior arm 3324 each extend laterally. In this example, each medial portion 3906 is attached to a respective one of the lateral portions 3907 of the central portion 3901 of the frame 3820. The superior arms 3298 and inferior arms 3324 extend freely away from the medial portion 3906 of each arm portion 3904 and from the central portion 3901 of the frame 3820.

[0353] With reference to Fig. 24C in particular, which is a cross-section view through the interface between the central portion 3901 of the frame 3820 and one of the arm portions 3904, each connection between a respective one of the arm portions 3904 and the central portion 3901 of the frame 3820 in this example comprises an alignment formation configured to align the respective arm portion 3904 to the central portion 3901 of the frame 3820. The alignment formation may comprise a recess 3908 in one of the central portion 3901 of the frame 3820 and the arm portion 3904, and a protrusion 3909 in the other one of the central portion 3901 of the frame 3820 and the arm portion 3904. In the example shown in Fig. 24C, the arm portion 3904 comprises the protrusion 3909 and the central portion 3901 of the frame 3820 comprises the recess 3908. In other examples, the protrusion 3909 may be provided to the central portion 3901 of the frame 3820 and the recess 3908 may be provided to the arm portion 3904. In this example, each of the protrusion 3909 and recess 3908 are elongate and extend from an inferior portion to a superior portion of the central portion 3901 of the frame 3820. In other examples, a different alignment formationA2578192 12.0 59may be provided, such as a plurality of studs and holes, complementary shoulders, or any other mechanical feature to align the arm portions 3904 to the central portion 3901 of the frame 3820.

[0354] In the example shown in Figs. 24A-24C, the arm portions 3904 are attached to the central portion 3901 of the frame 3820 by adhesive, such as a suitable glue. In other examples the arm portions 3904 may be welded to the central portion 3901. In further examples the arm portions 3904 may be mechanically connected or integrally formed with the central portion 3901. Advantageously, the alignment formation discussed above may provide mechanical strength to the connection between the arm portions 3904 and the central portion 3901, to supplement an adhesive or welding used to join the parts.

[0355] In each of the arm portions 3904 of the frame 3820, at least a portion of the superior arm 3298, at least a portion of the inferior arm 3324, and the medial portion 3906 are integrally formed by injection moulding. In the example shown in Figs. 24A-24C, the full lengths of the superior arm 3298, inferior arm 3324 and medial portion 3906 of each arm portion 3904 are integrally formed. However, at least part of the inferior headgear connector 3326 is formed separately, such as the magnet or ferromagnetic material, and a cover for the magnet / ferromagnetic material. The arm portions 3904 (e.g. the moulded portions thereof) may be formed from a thermoplastic polyester elastomer such as Hytrel™ or any other suitable material such as polypropylene, or the like. Hytrel™ or similar materials may provide for highly flexible arms which are able to conform to the curvature of the patient’s face and head while also transferring headgear tension to the cushion module 3150. The superior arm 3298 may comprise a textile sleeve. Some of the superior arm 3298 may lie against the patient’s face in use and the textile sleeve may advantageously help provide for a comfortable feel on the patient’s skin.

[0356] The central portion 3901 of the frame 3820 may be formed from injection moulding and may be formed from a copolymer such as Tritan™ , polycarbonate or another suitable material, such as any suitable thermoplastic material. The central portion 3901 of the frame 3820 may be substantially rigid or semi-rigid. The central portion 3901 may be clear, which may provide for a clean and aesthetically pleasing look. The central portion 3901 may also lie against and stiffen the cushion moduleA2578192 12.0 603150, which may be advantageous when an anterior wall of the cushion module 3150 is formed from a softer and / or more flexible material, such as an elastomeric material like silicone or TPE.4.3.7 Vent

[0357] In one form, the patient interface 3000 includes a vent 3400 constructed and arranged to allow for the washout of exhaled gases, e.g. carbon dioxide.

[0358] In certain forms the vent 3400 is configured to allow a continuous vent flow from an interior of the plenum chamber 3200 to ambient whilst the pressure within the plenum chamber is positive with respect to ambient. The vent 3400 is configured such that the vent flow rate has a magnitude sufficient to reduce rebreathing of exhaled CO2 by the patient while maintaining the therapeutic pressure in the plenum chamber in use.

[0359] One form of vent 3400 in accordance with the present technology comprises 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.

[0360] The vent 3400 may be located in the plenum chamber 3200. Alternatively, the vent 3400 is located in a decoupling structure, e.g., a swivel.4.3.8 Decoupling structure(s)

[0361] In one form the patient interface 3000 includes at least one decoupling structure, for example, a swivel or a ball and socket.4.3.9 Connection port

[0362] Connection port 3600 allows for connection to the air circuit 4170.4.3.10 Forehead support

[0363] In one form, the patient interface 3000 includes a forehead support 3700.4.3.11 Anti-asphyxia valve

[0364] In one form, the patient interface 3000 includes an anti-asphyxia valve.4.3.12 Ports

[0365] In one form of the present technology, a patient interface 3000 includes one or more ports that allow access to the volume within the plenum chamber 3200. In one form this allows a clinician to supply supplementary oxygen. In one form, this allows for the direct measurement of a property of gases within the plenum chamber 3200, such as the pressure.A2578192 12.0 614.4 RPT DEVICE

[0366] An RPT device 4000 in accordance with one aspect of the present technology comprises mechanical, pneumatic, and / or electrical components and is configured to execute one or more algorithms, such as any of the methods, in whole or in part, described herein. The RPT device 4000 may be configured to generate a flow of air for delivery to a patient’s airways, such as to treat one or more RPT device algorithms

[0367] As mentioned above, in some forms of the present technology, the central controller may be configured to implement one or more algorithms expressed as computer programs stored in a non-transitory computer readable storage medium, such as memory. The algorithms are generally grouped into groups referred to as modules.

[0368] In other forms of the present technology, some portion or all of the algorithms may be implemented by a controller of an external device such as the local external device or the remote external device. In such forms, data representing the input signals and / or intermediate algorithm outputs necessary for the portion of the algorithms to be executed at the external device may be communicated to the external device via the local external communication network or the remote external communication network. In such forms, the portion of the algorithms to be executed at the external device may be expressed as computer programs, such as with processor control instructions to be executed by one or more processor(s), stored in a non- transitory computer readable storage medium accessible to the controller of the external device. Such programs configure the controller of the external device to execute the portion of the algorithms.

[0369] In such forms, the therapy parameters generated by the external device via the therapy engine module (if such forms part of the portion of the algorithms executed by the external device) may be communicated to the central controller4.5 HUMIDIFIER4.5.1 Humidifier overview

[0370] In one form of the present technology there is provided a humidifier 5000 (e.g. as shown in Fig. 5A) to change the absolute humidity of air or gas for delivery to a patient relative to ambient air. Typically, the humidifier 5000 is used to increase theA2578192 12.0 62absolute humidity and increase the temperature of the flow of air (relative to ambient air) before delivery to the patient’s airways.

[0371] The humidifier 5000 may comprise a humidifier reservoir 5110, a humidifier inlet 5002 to receive a flow of air, and a humidifier outlet 5004 to deliver a humidified flow of air. In some forms, as shown in Fig. 5A and Fig. 5B, an inlet and an outlet of the humidifier reservoir 5110 may be the humidifier inlet 5002 and the humidifier outlet 5004 respectively. The humidifier 5000 may further comprise a humidifier base 5006, which may be adapted to receive the humidifier reservoir 5110 and comprise a heating element 5240. In examples the humidifier reservoir further comprises a conductive portion 5120, a locking lever 5135 and a water level indicator 5150.4.5.1.1 BREATHING WAVEFORMS

[0372] Fig. 6 shows a model typical breath waveform of a person while sleeping. The horizontal axis is time, and the vertical axis is respiratory flow rate. While the parameter values may vary, a typical breath may have the following approximate values: tidal volume Vt 0.5L, inhalation time Ti 1.6s, peak inspiratory flow rate Qpeak 0.4 L / s, exhalation time Te 2.4s, peak expiratory flow rate Qpeak -0.5 L / s. The total duration of the breath, Tlol. is about 4s. The person typically breathes at a rate of about 15 breaths per minute (BPM), with Ventilation Vent about 7.5 L / min. A typical duty cycle, the ratio of Ti to Ttot, is about 40%.

[0373] 4.6 GLOSSARY

[0374] For the purposes of the present technology disclosure, in certain forms of the present technology, one or more of the following definitions may apply. In other forms of the present technology, alternative definitions may apply.4.6.1 General

[0375] Air '. In certain forms of the present technology, air may be taken to mean atmospheric air, and in other forms of the present technology air may be taken to mean some other combination of breathable gases, e.g. oxygen enriched air.

[0376] Ambient'. In certain forms of the present technology, the term ambient will be taken to mean (i) external of the treatment system or patient, and (ii) immediately surrounding the treatment system or patient.A2578192 12.0 63

[0377] For example, ambient humidity with respect to a humidifier may be the humidity of air immediately surrounding the humidifier, e.g. the humidity in the room where a patient is sleeping. Such ambient humidity may be different to the humidity outside the room where a patient is sleeping.

[0378] In another example, ambient pressure may be the pressure immediately surrounding or external to the body.

[0379] In certain forms, ambient (e.g., acoustic) noise may be considered to be the background noise level in the room where a patient is located, other than for example, noise generated by an RPT device or emanating from a mask or patient interface. Ambient noise may be generated by sources outside the room.

[0380] Automatic Positive Airway Pressure (APAP) therapy. CPAP therapy in which the treatment pressure is automatically adjustable, e.g. from breath to breath, between minimum and maximum limits, depending on the presence or absence of indications of SDB events.

[0381] Continuous Positive Airway Pressure (CPAP) therapy. Respiratory pressure therapy in which the treatment pressure is approximately constant through a respiratory cycle of a patient. 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, for example, being increased in response to detection of indications of partial upper airway obstruction, and decreased in the absence of indications of partial upper airway obstruction.

[0382] Flow rate. The volume (or mass) of air delivered per unit time. Flow rate may refer to an instantaneous quantity. In some cases, a reference to flow rate will be a reference to a scalar quantity, namely a quantity having magnitude only. In other cases, a reference to flow rate will be a reference to a vector quantity, namely a quantity having both magnitude and direction. Flow rate may be given the symbol Q. ‘Flow rate’ is sometimes shortened to simply ‘flow’ or ‘airflow’.

[0383] In the example of patient respiration, a flow rate may be nominally positive for the inspiratory portion of a breathing cycle of a patient, and hence negative for the expiratory portion of the breathing cycle of a patient. Device flow rate, Qc is the flow rate of air leaving the RPT device. Total flow rate, Qt, is the flow rate of air and any supplementary gas reaching the patient interface via the air circuit. Vent flow rate, Qy, is the flow rate of air leaving a vent to allow washout of exhaledA2578192 12.0 64gases. Leak flow rate, QI, is the flow rate of leak from a patient interface system or elsewhere. Respiratory flow rate, Qr, is the flow rate of air that is received into the patient's respiratory system.

[0384] Flow therapy. Respiratory therapy comprising the delivery of a flow of air to an entrance to the airways at a controlled flow rate referred to as the treatment flow rate that is typically positive throughout the patient’s breathing cycle.

[0385] Humidifier'. The word humidifier will be taken to mean a humidifying apparatus constructed and arranged, or configured with a physical structure to be capable of providing a therapeutically beneficial amount of water (H2O) vapour to a flow of air to ameliorate a medical respiratory condition of a patient.

[0386] Leak'. The word leak will be taken to be an unintended flow of air. In one example, leak may occur as the result of an incomplete seal between a mask and a patient's face. In another example leak may occur in a swivel elbow to the ambient.

[0387] Noise, conducted (acoustic) '. Conducted noise in the present document refers to noise which is carried to the patient by the pneumatic path, such as the air circuit and the patient interface as well as the air therein. In one form, conducted noise may be quantified by measuring sound pressure levels at the end of an air circuit.

[0388] Noise, radiated (acoustic) '. Radiated noise in the present document refers to noise which is carried to the patient by the ambient air. In one form, radiated noise may be quantified by measuring sound power / pressure levels of the object in question according to ISO 3744.

[0389] Noise, vent (acoustic)'. Vent noise in the present document refers to noise which is generated by the flow of air through any vents such as vent holes of the patient interface.

[0390] Oxygen enriched air '. Air with a concentration of oxygen greater than that of atmospheric air (21%), for example at least about 50% oxygen, at least about 60% oxygen, at least about 70% oxygen, at least about 80% oxygen, at least about 90% oxygen, at least about 95% oxygen, at least about 98% oxygen, or at least about 99% oxygen. “Oxygen enriched air” is sometimes shortened to “oxygen”.

[0391] Medical Oxygen'. Medical oxygen is defined as oxygen enriched air with an oxygen concentration of 80% or greater.

[0392] Patient'. A person, whether or not they are suffering from a respiratory condition.A2578192 12.0 65

[0393] Pressure: Force per unit area. Pressure may be expressed in a range of units, including cmbhO, g-f / cm2and hectopascal. 1 cmFFO is equal to 1 g-f / cm2and is approximately 0.98 hectopascal (1 hectopascal = 100 Pa = 100 N / m2= 1 millibar ~ 0.001 atm). In this specification, unless otherwise stated, pressure is given in units of cmbhO.

[0394] The pressure in the patient interface is given the symbol Pm, while the treatment pressure, which represents a target value to be achieved by the interface pressure Pm at the current instant of time, is given the symbol Pt.

[0395] Respiratory Pressure Therapy. The application of a supply of air to an entrance to the airways at a treatment pressure that is typically positive with respect to atmosphere.

[0396] Ventilator'. A mechanical device that provides pressure support to a patient to perform some or all of the work of breathing.4.6.1.1 Materials & their properties

[0397] Hardness'. Refers to durometer or indentation hardness, which is a material property measured by indentation of an indentor (e.g., as measured in accordance with ASTM D2240).• ‘Soft’ materials may include silicone or thermo-plastic elastomer (TPE), and may, e.g. readily deform under finger pressure.• ‘Hard’ materials may include polycarbonate, polypropylene, and may not e.g. readily deform under finger pressure.

[0398] Silicone or Silicone Elastomer'. A synthetic rubber. In this specification, a reference to silicone is a reference to liquid silicone rubber (LSR) or a compression moulded silicone rubber (CMSR). One form of commercially available LSR is SILASTIC (included in 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.

[0399] Polycarbonate', a thermoplastic polymer of Bisphenol-A Carbonate.4.6.1.2 Mechanics

[0400] Axes:A2578192 12.0 66• Neutral axis'. An axis in the cross-section of a beam or plate along which there are no longitudinal stresses or strains.• Longitudinal axis'. An axis extending along the length of a shape. The axis generally passes through a center of the shape.• Circumferential axis'. An axis oriented perpendicularly with respect to the longitudinal axis. The axis may be specifically present in pipes, tubes, cylinders, or similar shapes with a circular and / or elliptical cross section.

[0401] Deformation'. The process where the original geometry of a member changes when subjected to forces, e.g. a force in a direction with respect to an axis. The process may include stretching or compressing, bending and, twisting.

[0402] Elasticity '. The ability of a material to return to its original geometry after deformation.

[0403] Floppy structure or component: A structure or component that will change shape, e.g. bend, when caused to support its own weight, within a relatively short period of time such as 1 second.

[0404] Resilience'. Ability of a material to absorb energy when deformed elastically and to release the energy upon unloading.

[0405] Resilient'. Will release substantially all of the energy when unloaded. Includes e.g. certain silicones, and thermoplastic elastomers.

[0406] Rigid structure or component: A structure or component that will not substantially change shape when subject to the loads typically encountered in use. An example of such a use may be setting up and maintaining a patient interface in sealing relationship with an entrance to a patient's airways, e.g. at a load of approximately 20 to 30 cmH20 pressure.

[0407] As an example, an I-beam may comprise a different bending stiffness (resistance to a bending load) in a first direction in comparison to a second, orthogonal direction. In another example, a structure or component may be floppy in a first direction and rigid in a second direction.

[0408] Stiffness (or rigidity) of a structure or component: The ability of the structure or component to resist deformation in response to an applied load. The load may be a force or a moment, e.g. compression, tension, bending or torsion. TheA2578192 12.0 67structure or component may offer different resistances in different directions. The inverse of stiffness is flexibility.

[0409] Viscous'. The ability of a material to resist flow.

[0410] Visco-elasticity : The ability of a material to display both elastic and viscous behaviour in deformation.

[0411] Yield: The situation when a material can no longer return back to its original geometry after deformation.4.6.1.3 Structural Elements

[0412] Compression member: A structural element that resists compression forces.

[0413] Elbow : An elbow is an example of a structure that directs an axis of flow of air travelling therethrough to change direction through an angle. In one form, the angle may be approximately 90 degrees. In another form, the angle may be more, or less than 90 degrees. The elbow may have an approximately circular cross-section. In another form the elbow may have an oval or a rectangular cross-section. In certain forms an elbow may be rotatable with respect to a mating component, e.g. about 360 degrees. In certain forms an elbow may be removable from a mating component, e.g. via a snap connection. In certain forms, an elbow may be assembled to a mating component via a one-time snap during manufacture, but not removable by a patient.

[0414] Frame: Frame will be taken to mean a mask structure that bears the load of tension between two or more points of connection with a headgear. A mask frame may be a non-airtight load bearing structure in the mask. However, some forms of mask frame may also be air-tight.

[0415] Membrane: Membrane will be taken to mean a typically thin element that has, preferably, substantially no resistance to bending, but has resistance to being stretched.

[0416] Tie (noun): A structure designed to resist tension.

[0417] Thin structures:• Beams, i. A beam may be relatively long in one dimension compared to the other two dimensions such that the smaller dimensions are comparatively thin compared to the long dimension• Membranes,A2578192 12.0 68i. Relatively long in two dimensions, with one thin dimension. Readily deforms in response to bending forces. Resists being stretched, (might also resist compression).• Plates & Shells i. These may be relatively long in two directions, with one thin dimension. They may have bending, tensile, and / or compressive stiffness.

[0418] Thick structures: Solids

[0419] Seal'. May be a noun form ("a seal") which refers to a structure, or a verb form (“to seal”) which refers to the effect. Two elements may be constructed and / or arranged to ‘seal’ or to effect ‘sealing’ therebetween without requiring a separate ‘seal’ element per se.

[0420] Shell'. A shell will be taken to mean a curved, relatively thin structure having bending, tensile and compressive stiffness. For example, a curved structural wall of a mask may be a shell. In some forms, a shell may be faceted. In some forms a shell may be airtight. In some forms a shell may not be airtight.

[0421] Stiffener. A stiffener will be taken to mean a structural component designed to increase the bending resistance of another component in at least one direction.

[0422] Strut'. A strut will be taken to be a structural component designed to increase the compression resistance of another component in at least one direction.

[0423] Swivel (noun) '. A subassembly of components configured to rotate about a common axis, preferably independently, preferably under low torque. In one form, the swivel may be constructed to rotate through an angle of at least 360 degrees. In another form, the swivel may be constructed to rotate through an angle less than 360 degrees. When used in the context of an air delivery conduit, the sub-assembly of components preferably comprises a matched pair of cylindrical conduits. There may be little or no leak flow of air from the swivel in use.4.6.2 Respiratory cycle

[0424] Apnea. According to some definitions, an apnea is said to have occurred when flow falls below a predetermined threshold for a duration, e.g. 10 seconds. An obstructive apnea will be said to have occurred when, despite patient effort, some obstruction of the airway does not allow air to flow. A central apnea will be said toA2578192 12.0 69have occurred when an apnea is detected that is due to a reduction in breathing effort, or the absence of breathing effort, despite the airway being patent. A mixed apnea occurs when a reduction or absence of breathing effort coincides with an obstructed airway.

[0425] Breathing rate '. The rate of spontaneous respiration of a patient, usually measured in breaths per minute.

[0426] Duty cycle '. The ratio of inhalation time, Ti to total breath time, Ttot.

[0427] Effort (breathing): The work done by a spontaneously breathing person attempting to breathe.

[0428] Expiratory portion of a breathing cycle: The period from the start of expiratory flow to the start of inspiratory flow.

[0429] Flow limitation'. Flow limitation will be taken to be the state of affairs in a patient's respiration where an increase in effort by the patient does not give rise to a corresponding increase in flow. Where flow limitation occurs during an inspiratory portion of the breathing cycle it may be described as inspiratory flow limitation.Where flow limitation occurs during an expiratory portion of the breathing cycle it may be described as expiratory flow limitation.

[0430] Types of flow limited inspiratory waveforms:(i) Flattened: Having a rise followed by a relatively flat portion, followed by a fall.(ii) M-shaped: Having two local peaks, one at the leading edge, and one at the trailing edge, and a relatively flat portion between the two peaks.(iii) Chair-shaped: Having a single local peak, the peak being at the leading edge, followed by a relatively flat portion.(iv) Reverse-chair shaped: Having a relatively flat portion followed by single local peak, the peak being at the trailing edge.

[0431] Efypopnea'. According to some definitions, a hypopnea is taken to be a reduction in flow, but not a cessation of flow. In one form, a hypopnea may be said to have occurred when there is a reduction in flow below a threshold rate for a duration. A central hypopnea will be said to have occurred when a hypopnea is detected that is due to a reduction in breathing effort. In one form in adults, either of the following may be regarded as being hypopneas:(i) a 30% reduction in patient breathing for at least 10 seconds plus an associated 4% desaturation; orA2578192 12.0 70(ii) a reduction in patient breathing (but less than 50%) for at least 10 seconds, with an associated desaturation of at least 3% or an arousal.

[0432] Hyperpnec . An increase in flow to a level higher than normal.

[0433] Inspiratory portion of a breathing cycle: The period from the start of inspiratory flow to the start of expiratory flow will be taken to be the inspiratory portion of a breathing cycle.

[0434] Patency (airway): The degree of the airway being open, or the extent to which the airway is open. A patent airway is open. Airway patency may be quantified, for example with a value of one (1) being patent, and a value of zero (0), being closed (obstructed).

[0435] Positive End-Expiratory Pressure (PEEP) '. The pressure above atmosphere in the lungs that exists at the end of expiration.

[0436] Peak flow rate Qpeak . The maximum value of flow rate during the inspiratory portion of the respiratory flow waveform.

[0437] Respiratory flow rate, patient airflow rate, respiratory airflow rate (Qr)These terms may be understood to refer to the RPT device’s estimate of respiratory flow rate, as opposed to “true respiratory flow rate” or “true respiratory flow rate”, which is the actual respiratory flow rate experienced by the patient, usually expressed in litres per minute.

[0438] Tidal volume (Vt): The volume of air inhaled or exhaled during normal breathing, when extra effort is not applied. In principle the inspiratory volume Vi (the volume of air inhaled) is equal to the expiratory volume Ve (the volume of air exhaled), and therefore a single tidal volume Vt may be defined as equal to either quantity. In practice the tidal volume Vt is estimated as some combination, e.g. the mean, of the inspiratory volume Vi and the expiratory volume Ve.

[0439] Inhalation Time (Ti): The duration of the inspiratory portion of the respiratory flow rate waveform.

[0440] Exhalation Time (Te): The duration of the expiratory portion of the respiratory flow rate waveform.

[0441] Total Time (Ttot): The total duration between the start of one inspiratory portion of a respiratory flow rate waveform and the start of the following inspiratory portion of the respiratory flow rate waveform.A2578192 12.0 71

[0442] Typical recent ventilation '. The value of ventilation around which recent values of ventilation Vent over some predetermined timescale tend to cluster, that is, a measure of the central tendency of the recent values of ventilation.

[0443] Upper airway obstruction (UAO): includes both partial and total upper airway obstruction. This may be associated with a state of flow limitation, in which the flow rate increases only slightly or may even decrease as the pressure difference across the upper airway increases (Starling resistor behaviour).

[0444] Ventilation (Vent): A measure of a rate of gas being exchanged by the patient’s respiratory system. Measures of ventilation may include one or both of inspiratory and expiratory flow, per unit time. When expressed as a volume per minute, this quantity is often referred to as “minute ventilation”. Minute ventilation is sometimes given simply as a volume, understood to be the volume per minute.4.6.3 Ventilation

[0445] Adaptive Servo-Ventilator (ASV): A servo-ventilator that has a changeable, rather than fixed target ventilation. The changeable target ventilation may be learned from some characteristic of the patient, for example, a respiratory characteristic of the patient.

[0446] Backup rate: A parameter of a ventilator that establishes the minimum breathing rate (typically in number of breaths per minute) that the ventilator will deliver to the patient, if not triggered by spontaneous respiratory effort.

[0447] Cycled: The termination of a ventilator's inspiratory phase. When a ventilator delivers a breath to a spontaneously breathing patient, at the end of the inspiratory portion of the breathing cycle, the ventilator is said to be cycled to stop delivering the breath.

[0448] Expiratory positive airway pressure (EPAP): a base pressure, to which a pressure varying within the breath is added to produce the desired interface pressure which the ventilator will attempt to achieve at a given time.

[0449] End expiratory pressure (EEP): Desired interface pressure which the ventilator will attempt to achieve at the end of the expiratory portion of the breath. If the pressure waveform template 11( ) is zero-valued at the end of expiration, i.e. 11(0) = 0 when = 1, the EEP is equal to the EPAP.A2578192 12.0 72

[0450] Inspiratory positive airway pressure (IPAP): Maximum desired interface pressure which the ventilator will attempt to achieve during the inspiratory portion of the breath.

[0451] Pressure support: A number that is indicative of the increase in pressure during ventilator inspiration over that during ventilator expiration, and generally means the difference in pressure between the maximum value during inspiration and the base pressure (e.g., PS = IPAP - EPAP). In some contexts, pressure support means the difference which the ventilator aims to achieve, rather than what it actually achieves.

[0452] Servo-ventilator: A ventilator that measures patient ventilation, has a target ventilation, and which adjusts the level of pressure support to bring the patient ventilation towards the target ventilation.

[0453] Spontaneous / Timed (S / T): A mode of a ventilator or other device that attempts to detect the initiation of a breath of a spontaneously breathing patient. If however, the device is unable to detect a breath within a predetermined period of time, the device will automatically initiate delivery of the breath.

[0454] Swing: Equivalent term to pressure support.

[0455] Triggered: When a ventilator, or other respiratory therapy device such as an RPT device or portable oxygen concentrator, delivers a volume of breathable gas to a spontaneously breathing patient, it is said to be triggered to do so. Triggering usually takes place at or near the initiation of the respiratory portion of the breathing cycle by the patient's efforts.4.6.4 Anatomy4.6.4.1 Anatomy of the face

[0456] Ala: the external outer wall or "wing" of each nostril (plural: alar)

[0457] Alar angle: An angle formed between the ala of each nostril.

[0458] Alare: The most lateral point on the nasal ala.

[0459] Alar curvature (or alar crest) point: The most posterior point in the curved base line of each ala, found in the crease formed by the union of the ala with the cheek.

[0460] Auricle: The whole external visible part of the ear.

[0461] (nose) Bony framework: The bony framework of the nose comprises the nasal bones, the frontal process of the maxillae and the nasal part of the frontal bone.A2578192 12.0 73

[0462] (nose) Cartilaginous framework: The cartilaginous framework of the nose comprises the septal, lateral, major and minor cartilages.

[0463] Columella: the strip of skin that separates the nares and which runs from the pronasale to the upper lip.

[0464] Columella angle: The angle between the line drawn through the midpoint of the nostril aperture and a line drawn perpendicular to the Frankfort horizontal while intersecting subnasale.

[0465] Frankfort horizontal plane: A line extending from the most inferior point of the orbital margin to the left tragion. The tragi on is the deepest point in the notch superior to the tragus of the auricle.

[0466] Glabella: Located on the soft tissue, the most prominent point in the midsagittal plane of the forehead.

[0467] Lateral nasal cartilage: A generally triangular plate of cartilage. Its superior margin is attached to the nasal bone and frontal process of the maxilla, and its inferior margin is connected to the greater alar cartilage.

[0468] Lip, lower (labrale inferius): The lip extending between the subnasale and the mouth.

[0469] Lip, upper (labrale superius): The lip extending between the mouth and the supramenton.

[0470] Greater alar cartilage: A plate of cartilage lying below the lateral nasal cartilage. It is curved around the anterior part of the naris. Its posterior end is connected to the frontal process of the maxilla by a tough fibrous membrane containing three or four minor cartilages of the ala.

[0471] Nares (Nostrils): Approximately ellipsoidal apertures forming the entrance to the nasal cavity. The singular form of nares is naris (nostril). The nares are separated by the nasal septum.

[0472] Naso-labial sulcus or Naso-labial fold: The skin fold or groove that runs from each side of the nose to the comers of the mouth, separating the cheeks from the upper lip.

[0473] Naso-labial angle: The angle between the columella and the upper lip, while intersecting subnasale.

[0474] Otobasion inferior: The lowest point of attachment of the auricle to the skin of the face.A2578192 12.0 74

[0475] Otobasion superior: The highest point of attachment of the auricle to the skin of the face.

[0476] Pronasale: the most protruded point or tip of the nose, which can be identified in lateral view of the rest of the portion of the head.

[0477] Philtrum: the midline groove that runs from lower border of the nasal septum to the top of the lip in the upper lip region.

[0478] Pogonion: Located on the soft tissue, the most anterior midpoint of the chin.

[0479] Ridge (nasal): The nasal ridge is the midline prominence of the nose, extending from the Sellion to the Pronasale.

[0480] Sagittal plane: A vertical plane that passes from anterior (front) to posterior (rear). The midsagittal plane is a sagittal plane that divides the body into right and left halves.

[0481] Sellion: Located on the soft tissue, the most concave point overlying the area of the frontonasal suture.

[0482] Septal cartilage (nasal): The nasal septal cartilage forms part of the septum and divides the front part of the nasal cavity.

[0483] Subalare: The point at the lower margin of the alar base, where the alar base joins with the skin of the superior (upper) lip.

[0484] Subnasal point: Located on the soft tissue, the point at which the columella merges with the upper lip in the midsagittal plane.

[0485] Supramenton: The point of greatest concavity in the midline of the lower lip between labrale inferius and soft tissue pogonion

[0486] Anatomy of the skull

[0487] Frontal bone: The frontal bone includes a large vertical portion, the squama frontalis, corresponding to the region known as the forehead.

[0488] Mandible: The mandible forms the lower jaw. The mental protuberance is the bony protuberance of the jaw that forms the chin.

[0489] Maxilla: The maxilla forms the upper jaw and is located above the mandible and below the orbits. The frontal process of the maxilla projects upwards by the side of the nose, and forms part of its lateral boundary.

[0490] Nasal bones: The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face, and form, by their junction, the "bridge" of the nose.A2578192 12.0 75

[0491] Nasion: The intersection of the frontal bone and the two nasal bones, a depressed area directly between the eyes and superior to the bridge of the nose.

[0492] Occipital bone: The occipital bone is situated at the back and lower part of the cranium. It includes an oval aperture, the foramen magnum, through which the cranial cavity communicates with the vertebral canal. The curved plate behind the foramen magnum is the squama occipitalis.

[0493] Orbit: The bony cavity in the skull to contain the eyeball.

[0494] Parietal bones: The parietal bones are the bones that, when joined together, form the roof and sides of the cranium.

[0495] Temporal bones: The temporal bones are situated on the bases and sides of the skull, and support that part of the face known as the temple.

[0496] Zygomatic bones: The face includes two zygomatic bones, located in the upper and lateral parts of the face and forming the prominence of the cheek.4.6.4.1 Anatomy of the respiratory system

[0497] Diaphragm: A sheet of muscle that extends across the bottom of the rib cage. The diaphragm separates the thoracic cavity, containing 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.

[0498] Larynx: The larynx, or voice box houses the vocal folds and connects the inferior part of the pharynx (hypopharynx) with the trachea.

[0499] Lungs: The organs of respiration in humans. The conducting zone of the lungs contains the trachea, the bronchi, the bronchioles, and the terminal bronchioles. The respiratory zone contains the respiratory bronchioles, the alveolar ducts, and the alveoli.

[0500] Nasal cavity: The nasal cavity (or nasal fossa) is a large air filled space above and behind the nose in the middle of the face. The nasal cavity is divided in two by a vertical fin called the nasal septum. On the sides of the nasal cavity are three horizontal outgrowths called nasal conchae (singular "concha") or turbinates. To the front of the nasal cavity is the nose, while the back blends, via the choanae, into the nasopharynx.

[0501] Pharynx: The part of the throat situated immediately inferior to (below) the nasal cavity, and superior to the oesophagus and larynx. The pharynx is conventionally divided into three sections: the nasopharynx (epipharynx) (the nasalA2578192 12.0 76part of the pharynx), the oropharynx (mesopharynx) (the oral part of the pharynx), and the laryngopharynx (hypopharynx).4.6.5 Patient interface

[0502] Anti-asphyxia valve (AAV): The component or sub-assembly of a mask system that, by opening to atmosphere in a failsafe manner, reduces the risk of excessive CO2 rebreathing by a patient.

[0503] Headgear: Headgear will be taken to mean a form of positioning and stabilising structure designed to hold a device, e.g., a mask, on a head.

[0504] Plenum chamber: a mask plenum chamber will be taken to mean a portion of a patient interface having walls at least partially enclosing a volume of space, the volume having air therein pressurised above atmospheric pressure in use. A shell may form part of the walls of a mask plenum chamber.

[0505] Seal: May be a noun form ("a seal") which refers to a structure, or a verb form (“to seal”) which refers to the effect. Two elements may be constructed and / or arranged to ‘seal’ or to effect ‘sealing’ therebetween without requiring a separate ‘seal’ element per se.

[0506] Vent: (noun): A structure that allows a flow of air from an interior of the mask, or conduit, to ambient air for clinically effective washout of exhaled gases. For example, a clinically effective washout may involve a flow rate of about 10 litres per minute to about 100 litres per minute, depending on the mask design and treatment pressure.4.6.6 Shape of structures

[0507] Products in accordance with the present technology may comprise one or more three-dimensional mechanical structures, for example a mask cushion or an impeller. The three-dimensional structures may be bounded by two-dimensional surfaces. These surfaces may be distinguished using a label to describe an associated surface orientation, location, function, or some other characteristic. For example a structure may comprise one or more of an anterior surface, a posterior surface, an interior surface and an exterior surface. In another example, a seal-forming structure may comprise a face-contacting (e.g. outer) surface, and a separate non-facecontacting (e.g. underside or inner) surface. In another example, a structure may comprise a first surface and a second surface.A2578192 12.0 77

[0508] To facilitate describing the shape of the three-dimensional structures and the surfaces, we first consider a cross-section through a surface of the structure at a point, / ?. See Fig. 3B to Fig. 3F, which illustrate examples of cross-sections at point p on a surface, and the resulting plane curves. Figs. 3B to 3F also illustrate an outward normal vector at p. The outward normal vector at p points away from the surface. In some examples we describe the surface from the point of view of an imaginary small person standing upright on the surface.4.6.6.1 Curvature in one dimension

[0509] The curvature of a plane curve at p may be described as having a sign (e.g. positive, negative) and a magnitude (e.g. 1 / radius of a circle that just touches the curve at p).

[0510] Positive curvature: If the curve at p turns towards the outward normal, the curvature at that point will be taken to be positive (if the imaginary small person leaves the point p they must walk uphill). See Fig. 3B (relatively large positive curvature compared to Fig. 3C) and Fig. 3C (relatively small positive curvature compared to Fig. 3B). Such curves are often referred to as concave.

[0511] Zero curvature: If the curve at p is a straight line, the curvature will be taken to be zero (if the imaginary small person leaves the point p, they can walk on a level, neither up nor down). See Fig. 3D.

[0512] Negative curvature: If the curve at p turns away from the outward normal, the curvature in that direction at that point will be taken to be negative (if the imaginary small person leaves the point p they must walk downhill). See Fig. 3E (relatively small negative curvature compared to Fig. 3F) and Fig. 3F (relatively large negative curvature compared to Fig. 3E). Such curves are often referred to as convex.4.6.6.1 Curvature of two dimensional surfaces

[0513] A description of the shape at a given point on a two-dimensional surface in accordance with the present technology may include multiple normal crosssections. The multiple cross-sections may cut the surface in a plane that includes the outward normal (a “normal plane”), and each cross-section may be taken in a different direction. Each cross-section results in a plane curve with a corresponding curvature. The different curvatures at that point may have the same sign, or a different sign. Each of the curvatures at that point has a magnitude, e.g. relatively small. The plane curves in Figs. 3B to 3F could be examples of such multiple cross-sections at a particular point.A2578192 12.0 78

[0514] Principal curvatures and directions: The directions of the normal planes where the curvature of the curve takes its maximum and minimum values are called the principal directions. In the examples of Fig. 3B to Fig. 3F, the maximum curvature occurs in Fig. 3B, and the minimum occurs in Fig. 3F, hence Fig. 3B and Fig. 3F are cross sections in the principal directions. The principal curvatures at p are the curvatures in the principal directions.

[0515] Region of a surface: A connected set of points on a surface. The set of points in a region may have similar characteristics, e.g. curvatures or signs.

[0516] Saddle region: A region where at each point, the principal curvatures have opposite signs, that is, one is positive, and the other is negative (depending on the direction to which the imaginary person turns, they may walk uphill or downhill).

[0517] Dome region: A region where at each point the principal curvatures have the same sign, e.g. both positive (a “concave dome”) or both negative (a “convex dome”).

[0518] Cylindrical region: A region where one principal curvature is zero (or, for example, zero within manufacturing tolerances) and the other principal curvature is non-zero.

[0519] Planar region: A region of a surface where both of the principal curvatures are zero (or, for example, zero within manufacturing tolerances).

[0520] Edge of a surface: A boundary or limit of a surface or region.

[0521] Path: In certain forms of the present technology, ‘path’ will be taken to mean a path in the mathematical - topological sense, e.g. a continuous space curve from f(0) to f(l) on a surface. In certain forms of the present technology, a ‘path’ may be described as a route or course, including e.g. a set of points on a surface. (The path for the imaginary person is where they walk on the surface, and is analogous to a garden path).

[0522] Path length: In certain forms of the present technology, ‘path length’ will be taken to mean the distance along the surface from f(0) to f(l), that is, the distance along the path on the surface. There may be more than one path between two points on a surface and such paths may have different path lengths. (The path length for the imaginary person would be the distance they have to walk on the surface along the path).

[0523] Straight-line distance: The straight-line distance is the distance between two points on a surface, but without regard to the surface. On planar regions, thereA2578192 12.0 79would be a path on the surface having the same path length as the straight-line distance between two points on the surface. On non-planar surfaces, there may be no paths having the same path length as the straight-line distance between two points. (For the imaginary person, the straight-line distance would correspond to the distance ‘as the crow flies’.)4.6.6.3 Space curves

[0524] Space curves: Unlike a plane curve, a space curve does not necessarily lie in any particular plane. A space curve may be closed, that is, having no endpoints. A space curve may be considered to be a one-dimensional piece of three-dimensional space. An imaginary person walking on a strand of the DNA helix walks along a space curve. A typical human left ear comprises a helix, which is a left-hand helix, see Fig. 3Q. A typical human right ear comprises a helix, which is a right-hand helix, see Fig. 3R. Fig. 3S shows a right-hand helix. The edge of a structure, e.g. the edge of a membrane or impeller, may follow a space curve. In general, a space curve may be described by a curvature and a torsion at each point on the space curve. Torsion is a measure of how the curve turns out of a plane. Torsion has a sign and a magnitude. The torsion at a point on a space curve may be characterised with reference to the tangent, normal and binormal vectors at that point.

[0525] Tangent unit vector (or unit tangent vector): For each point on a curve, a vector at the point specifies a direction from that point, as well as a magnitude. A tangent unit vector is a unit vector pointing in the same direction as the curve at that point. If an imaginary person were flying along the curve and fell off her vehicle at a particular point, the direction of the tangent vector is the direction she would be travelling.

[0526] Unit normal vector: As the imaginary person moves along the curve, this tangent vector itself changes. The unit vector pointing in the same direction that the tangent vector is changing is called the unit principal normal vector. It is perpendicular to the tangent vector.

[0527] Binormal unit vector: The binormal unit vector is perpendicular to both the tangent vector and the principal normal vector. Its direction may be determined by a right-hand rule (see e.g. Fig. 3P), or alternatively by a left-hand rule (Fig. 30).

[0528] Osculating plane: The plane containing the unit tangent vector and the unit principal normal vector. See Figures 30 and 3P.A2578192 12.0 80

[0529] Torsion of a space curve: The torsion at a point of a space curve 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 which lies in a plane has zero torsion. A space curve which deviates a relatively small amount from the osculating plane will have a relatively small magnitude of torsion (e.g. a gently sloping helical path). A space curve which deviates a relatively large amount from the osculating plane will have a relatively large magnitude of torsion (e.g. a steeply sloping helical path). With reference to Fig. 3S, since T2>T1, the magnitude of the torsion near the top coils of the helix of Fig. 3S is greater than the magnitude of the torsion of the bottom coils of the helix of Fig. 3S

[0530] With reference to the right-hand rule of Fig. 3P, a space curve turning towards the direction of the right-hand binormal may be considered as having a righthand positive torsion (e.g. a right-hand helix as shown in Fig. 3S). A space curve turning away from the direction of the right-hand binormal may be considered as having a right-hand negative torsion (e.g. a left-hand helix).

[0531] Equivalently, and with reference to a left-hand rule (see Fig. 30), a space curve turning towards the direction of the left-hand binormal may be considered as having a left-hand positive torsion (e.g. a left-hand helix). Hence left-hand positive is equivalent to right-hand negative. See Fig. 3T.4.6.6.4 Holes

[0532] A surface may have a one-dimensional hole, e.g. a hole bounded by a plane curve or by a space curve. Thin structures (e.g. a membrane) with a hole, may be described as having a one-dimensional hole. See for example the one dimensional hole in the surface of structure shown in Fig. 31, bounded by a plane curve.

[0533] A structure may have a two-dimensional hole, e.g. a hole bounded by a surface. For example, an inflatable tyre has a two dimensional hole bounded by the interior surface of the tyre. In another example, a bladder with a cavity for air or gel could have a two-dimensional hole. See for example the cushion of Fig. 3L and the example cross-sections therethrough in Fig. 3M and Fig. 3N, with the interior surface bounding a two dimensional hole indicated. In a yet another example, a conduit may comprise a one-dimension hole (e.g. at its entrance or at its exit), and a two-dimension hole bounded by the inside surface of the conduit. See also the two dimensional hole through the structure shown in Fig. 3K, bounded by a surface as shown.A2578192 12.0 814.7 OTHER REMARKS

[0534] A portion of the disclosure of this patent document contains material which 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 Patent Office patent files or records, but otherwise reserves all copyright rights whatsoever.

[0535] Unless the context clearly dictates otherwise and where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit, between the upper and lower limit of that range, and any other stated or intervening value in that stated range is encompassed within the technology. The upper and lower limits of these intervening ranges, which may be independently included in the intervening ranges, are also encompassed within the technology, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the technology.

[0536] Furthermore, where a value or values are stated herein as being implemented as part of the technology, it is understood that such values may be approximated, unless otherwise stated, and such values may be utilized to any suitable significant digit to the extent that a practical technical implementation may permit or require it.

[0537] Furthermore, “approximately”, “substantially”, “about”, or any similar term used herein means + / - 5-10% of the recited value.

[0538] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this technology belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present technology, a limited number of the exemplary methods and materials are described herein.

[0539] When a particular material is identified as being used to construct a component, obvious alternative materials with similar properties may be used as a substitute. Furthermore, unless specified to the contrary, any and all components herein described are understood to be capable of being manufactured and, as such, may be manufactured together or separately.A2578192 12.0 82

[0540] It must be noted that as used herein and in the appended claims, the singular forms "a", "an", and "the" include their plural equivalents, unless the context clearly dictates otherwise.

[0541] All publications mentioned herein are incorporated herein by reference in their entirety to disclose and describe the methods and / or materials which are the subject of those publications. 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 publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates, which may need to be independently confirmed.

[0542] The terms "comprises" and "comprising" should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.

[0543] The subject headings used in the detailed description are included only for the ease of reference of the reader and should not be used to limit the subject matter found throughout the disclosure or the claims. The subject headings should not be used in construing the scope of the claims or the claim limitations.

[0544] Although the technology herein has been described with reference to particular examples, it is to be understood that these examples are merely illustrative of the principles and applications of the technology. In some instances, the terminology and symbols may imply specific details that are not required to practice the technology. For example, although the terms "first" and "second" may be used, unless otherwise specified, they are not intended to indicate any order but may be utilised to distinguish between distinct elements. Furthermore, although process steps in the methodologies may be described or illustrated in an order, such an ordering is not required. Those skilled in the art will recognize that such ordering may be modified and / or aspects thereof may be conducted concurrently or even synchronously.

[0545] It is therefore to be understood that numerous modifications may be made to the illustrative examples and that other arrangements may be devised without departing from the spirit and scope of the technology.A2578192 12.0 834.8 REFERENCE SIGNS LIST1000 patient1100 bed partner3000 patient interface3100 seal - forming structure3150 cushion module3200 plenum chamber3202 chassis portion3204 anterior wall3205 cutout3206 textile layer3207 thin resilient portion3208 flange3210 chord3220 superior point3230 inferior point3236 thickened portion3240 channel or groove3254 plenum chamber inlet port3280 frame3282 frame side portion3284 upper portion3286 superior end (of side portion)3288 lower portion3290 inferior end (of side portion)3292 connection point3294 hole for connection3296 projecting portion3298 upper arms3299 thinned area3300 positioning and stabilising structure3302 headgear3302-1 headgearA2578192 12.0 843304-1 inferior strap3305-1 superior strap3306-1 magnetic member3307-1 rear strap3310 strap3322 upper headgear connector3324 lower arms3326 lower headgear connectors3327 central portion3370-1 magnet3400 vent3600 connection port3610 elbow3700 forehead support3901 central portion of frame3904 frame arm portions3905 frame opening3907 frame lateral portions3908 alignment formation recess3909 alignment formation protrusion3961 frame connector portions3962 frame protrusions4000 RPT device5000 humidifier5002 humidifier inlet5004 humidifier outlet5006 humidifier base5110 reservoir5120 conductive portion5130 humidifier reservoir dock5135 locking lever5150 water level indicatorA2578192 12.0 85

Claims

5 CLAIMS1. A frame for a patient interface, the frame comprising first and second side portions, an upper portion connecting the first side portion to the second side portion, the frame further comprising a lower portion which connects an inferior end of the first side portion to an inferior end of the second side portion, wherein the side portions are less flexible than at least one of the upper portion and lower portion.

2. The frame of claim 1, wherein the upper portion is connected to the superior ends of the first and second side portions.

3. The frame of claim 1, wherein the upper portion is connected between the superior and inferior ends of the side portions, towards the superior ends;4. The frame of any one of claims 1 to 3, wherein at least one headgear connector is connected to each of the side portions.

5. The frame of any one of the preceding claims, wherein the inferior ends of the side portions overlie the patient’s cheeks below the patient’s mouth.

6. The frame of any one of the preceding claims, wherein the superior ends of the side portions overlie the patient’s cheeks, between the patient’s nose and mouth.

7. The frame of any one of claims 1 to 5, wherein the superior ends of the side portions lie adjacent the patient’s nose.

8. The frame of any one of the preceding claims, wherein the side portions are between 1 mm and 4 mm thick.

9. The frame of any one of the preceding claims, wherein each side portion comprises at least one connection point for connection to a cushion module;10. The frame of claim 9, wherein each side portion comprises a plurality of connection points for connection to a cushion module.

11. The frame of claim 9 or 10, wherein the connection points comprise apertures configured to receive projecting portions provided to the cushion module.A2578192 12.0 8612. The frame of any one of the preceding claims, wherein the upper portion is substantially U-shaped when viewed from in front.

13. The frame of any one claims 1 to 12, wherein the upper portion is substantially straight when viewed from in front.

14. The frame of any one of the preceding claims, wherein the side portions, upper portion and lower portion are formed integrally as one piece.

15. The frame of any one of claims 1 to 13, wherein one or both of the upper and lower portions are formed in a separate step from the formation of the side portions.

16. The frame of claim 15, wherein one or both of the upper and lower portions are formed by an overmoulding process.

17. The frame of claim 15, wherein one or both of the upper and lower portions are connected to the side portions by a connecting means.

18. The frame of any one of the preceding claims, wherein each side portion comprises an upper arm, wherein each upper arm comprises a headgear connector.

19. The frame of claim 18, wherein the headgear connector comprises a slot configured to receive a headgear strap.

20. The frame of claim 18 or 19, wherein each upper arm comprises a flexible portion.

21. A patient interface comprising a cushion module connected to the frame of any one of claims 1 to 20.

22. The patient interface of claim 21, wherein the cushion module comprises a flexible chassis portion.

23. A patient interface comprising a plenum chamber defined, at least in part by a chassis portion, a seal forming structure connected to the chassis portion, and a frame, the frame comprising first and second side portions, an upper portionA2578192 12.0 87connecting a superior end of the first side portion to a superior end of the second side portion, the frame further comprising a lower portion which connects an inferior end of the first side portion to an inferior end of the second side portion, wherein the frame extends around an outer perimeter of the chassis portion.

24. The patient interface of claim 23, wherein an anterior wall of the chassis portion comprises a superior cutout.

25. The patient interface of claim 24, wherein the upper portion of the frame is configured to extend around a perimeter of the cutout.

26. The patient interface of claim 23, wherein the upper portion of the frame is configured to extend below the cutout.

27. A patient interface comprising a plenum chamber defined, at least in part by a chassis portion, a seal forming structure connected to the chassis portion, a first frame portion and a second frame portion, wherein the frame portions are connectable to the chassis portion but the first frame portion is not connected to the second frame portion, each frame portion extending along a lateral edge of the chassis portion, and wherein each frame portion comprises at least one headgear connector.

28. The patient interface of claim 27, wherein the chassis portion is flexible.

29. The patient interface of claim 27 or 28, wherein the inferior ends of the side portions overlie the patient’s cheeks below the patient’s mouth.

30. The patient interface of claim 27, 28 or 29, wherein the superior ends of the side portions overlie the patient’s cheeks, between the patient’s nose and mouth.

31. The patient interface of claim 27, 28 or 29, wherein the superior ends of the side portions lie adjacent the patient’s nose.

32. The patient interface of any one of claims 27 to 31, wherein the side portions are between 1 mm and 4 mm thick.A2578192 12.0 8833. The patient interface of any one of claims 27 to 32, wherein each side portion comprises at least one connection point for connection to the cushion module.

34. The patient interface of claim 22, wherein each side portion comprises a plurality of connection points for connection to the cushion module.

35. The patient interface of claim 33 or 34, wherein the connection points comprise apertures configured to receive projecting portions provided to the cushion module.

36. A frame for a patient interface comprising a pair of upper arms, a pair of lower arms, the upper and lower arms connected to a central portion, wherein the central portion comprises an aperture configured to allow an air circuit connector to extend through the central portion, and wherein each of the upper and lower arms comprises a headgear connection means.

37. The frame of claim 36, wherein the frame is moulded in one piece.

38. The frame of claim 36 or 37, wherein each upper arm comprises a flexible portion.

39. The frame of claim 36, 37 or 38, wherein the frame comprises venting features adjacent the aperture.

40. A patient interface constructed and arranged to form a seal with a region of the patient’s face, including a nose bridge region, and surrounding an entrance to the patient’s airways, the patient interface including: a plenum chamber defined, at least in part, by a chassis portion, wherein at least the portion of the chassis portion is relatively flexible; a seal-forming structure connected to the chassis portion, wherein the seal forming structure includes a textile layer, wherein the perimeter of the chassis portion includes a cutout, which in use corresponds to at least the nose bridge region of the patient’s face, wherein the textile layer covers the cutout,A2578192 12.0 89and wherein an anterior wall of the chassis portion comprises a stiffening portion, the stiffening portion provided substantially adjacent a boundary between the anterior wall and a posterior wall of the chassis portion.

41. The patient interface of claim 40, wherein the stiffening portion is elongate and is positioned substantially parallel to the boundary between the anterior wall and the posterior wall.

42. The patient interface of claim 41, wherein a ratio of the height of the stiffening portion to the width of the stiffening portion is at least 2: 1.

43. The patient interface of any one of claims 40 to 42, wherein the stiffening portion is made from a different material to the anterior wall of the chassis portion.

44. The patient interface of any one of claims 40 to 43, wherein the stiffening portion is made from a less flexible material than the anterior wall of the chassis portion.

45. The patient interface of claim 44, wherein the stiffening portion is made from a rigid or semi-rigid material.

46. The patient interface of claim 45, wherein the stiffening portion is made from polycarbonate or polyester.

47. The patient interface of claim 44, 45 or 46 wherein the stiffening portion is overmoulded to the chassis portion, or are affixed to the chassis portion after moulding of the chassis portion.

48. The patient interface of any one of claims 40 to 47 wherein the stiffening portion is embedded in the anterior wall.

49. The patient interface of claim 48, wherein no part of the stiffening portion is not encased within the anterior wall.

50. The patient interface of claim 48, wherein a portion of the stiffening portion is not encased within the anterior wall.A2578192 12.0 9051. The patient interface of claim 50, wherein the portion of the stiffening portion which is not encased within the anterior wall is provided with means for connection to a frame.

52. The patient interface of any one of claims 40 to 51, comprising a second stiffening portion provided to a laterally opposite side of the anterior wall of the chassis portion.A2578192 12.0 91

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