Headgear for a patient interface

Abstract

A strap for a positioning and stabilising structure for a patient interface, the positioning and stabilising structure configured to provide a force to hold a seal- forming structure of the patient interface in a therapeutically effective position on the patient's head during use of the patient interface for treatment of sleep disordered breathing, the strap comprising: a body having a length, a width transverse to the length, and a pair of end portions at opposite ends of the length, the end portions being constructed and arranged to connect to a portion of the patient interface in use; wherein the body of the strap comprises a user-facing surface configured to engage the user's hair and / or skin in use, the user-facing surface having a first surface portion and a second surface portion, the first surface portion providing a first coefficient of friction between the strap and the user's hair or skin, the second surface portion providing a second coefficient of friction between the strap and the user's hair or skin, the second coefficient of friction being greater than the first coefficient of friction.

Description

HEADGEAR FOR A PATIENT INTERFACE1 CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Singapore Patent Application No. 10202403788R, filed 3 December 2024, the entire contents of which are hereby incorporated by reference.2 BACKGROUND OF THE TECHNOLOGY2.1 FIELD OF THE TECHNOLOGY

[0002] The present technology relates to one or more of the screening, diagnosis, monitoring, treatment, prevention and amelioration of respiratory-related disorders. The present technology also relates to medical devices or apparatus, and their use.2.2 DESCRIPTION OF THE RELATED ART2.2.1 Human Respiratory System and its Disorders

[0003] The respiratory system of the body facilitates gas exchange. The nose and mouth form the entrance to the airways of a patient.

[0004] 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 respirator}' 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.

[0005] A range of respiratory disorders exist. Certain disorders may be characterised by particular events, e.g. apneas, hypopneas, and hyperpneas.

[0006] 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.

[0007] A range of therapies have been used to treat or ameliorate such conditions. Furthermore, otherwise healthy individuals may take advantage of such therapies toprevent respiratory disorders from arising. However, these have a number of shortcomings.2.2.2 Therapies

[0008] 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.2.2.2.1 Respiratory pressure therapies

[0009] 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).

[0010] Continuous Positive Airway Pressure (CPAP) therapy has been used to treat Obstructive Sleep Apnea (OSA). The mechanism of action is that continuous positive airway pressure acts as a pneumatic splint and may prevent upper airway occlusion, such as by pushing the soft palate and tongue forward and away from the posterior oropharyngeal wall. Treatment of OSA by CPAP therapy may be voluntary, and hence patients may elect not to comply with therapy if they find devices used to provide such therapy one or more of: uncomfortable, difficult to use, expensive and aesthetically unappealing.2.2.3 Respiratory Therapy Systems

[0011] 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.

[0012] 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.2.2.3.1 Patient Interface

[0013] 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 cm I FC) relative to ambient pressure. For other forms of therapy, such as the delivery of oxygen, the patient interface may not include a seal sufficient to facilitate delivery to the airways of a supply of gas at a positive pressure of about 10 cmFhO. 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.

[0014] 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.

[0015] 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.

[0016] Certain masks may cause some patients a feeling of claustrophobia, unease and / or may feel overly obtrusive.

[0017] 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.

[0018] 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.

[0019] CPAP therapy is highly effective to treat certain respiratory disorders, provided patients comply with therapy. If a mask is uncomfortable, or difficult to usea 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.

[0020] 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.

[0021] For these reasons, patient interfaces for delivery of CPAP during sleep form a distinct field.2.2.3.1.1 Seal-forming structure

[0022] 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.

[0023] 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 clement 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 of patient 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.2.2.3.1.2 Positioning and Stabilising Structure

[0024] 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 andstabilising 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.

[0025] 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.

[0026] 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.2.2.3.1.3 Pressurised Air Conduit

[0027] 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.2.2.3.1.4 Pressurised Air Conduit used for Positioning / Stabilising the Seal- Forming Structure

[0028] Another type of treatment system comprises a patient interface in which a tube that delivers pressurised ah' 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 respirator}' 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 arc 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.

[0029] 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.2.2.3.2 Respiratory Pressure Therapy (RPT) Deviee

[0030] 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.

[0031] The designer of a device may be presented with an infinite number of choices to make. Design criteria often conflict, meaning that certain design choices are far from routine or inevitable. Furthermore, the comfort and efficacy of certain aspects may be highly sensitive to small, subtle changes in one or more parameters.2.2.3.3 Air circuit

[0032] 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.2.2.3.4 Humidifier

[0033] 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.2.2.3.5 Vent technologies

[0034] 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, c.g., to ambient.3 BRIEF SUMMARY OF THE TECHNOLOGY

[0035] The present technology is directed towards providing medical devices used in the screening, diagnosis, monitoring, amelioration, treatment, or prevention ofrespiratory disorders having one or more of improved comfort, cost, efficacy, ease of use and manufacturability.

[0036] A first aspect of the present technology relates to apparatus used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respirator}' disorder.

[0037] Another aspect of the present technology relates to methods used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respirator}' disorder.

[0038] 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.

[0039] 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.

[0040] One form of the present technology comprises a patient interface comprising a plenum chamber, a seal-forming structure, and a positioning and stabilising structure.

[0041] One form of the present technology comprises patient interface comprising a plenum chamber pressurisable to a therapeutic pressure of at least 4 cmH20 above ambient air pressure. The plenum chamber includes at least one plenum chamber inlet port sized and structured to receive a flow of ah' 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.

[0042] Another aspect of the present technology is a strap for a positioning and stabilising structure for a patient interface, the positioning and stabilising structure configured to provide a force to hold a seal-forming structure of the patient interfacein a therapeutically effective position on the patient’s head during use of the patient interface for treatment of sleep disordered breathing, the strap comprising: a body having a length, a width transverse to the length, and a pair of end portions at opposite ends of the length, the end portions being constructed and arranged to connect to a portion of the patient interface in use; wherein the body of the strap comprises a user-facing surface configured to engage the user’s hair and / or skin in use, the user-facing surface having a first surface portion and a second surface portion, the first surface portion providing a first coefficient of friction between the strap and the user’ s hair or skin, the second surface portion providing a second coefficient of friction between the strap and the user’s hair or skin, the second coefficient of friction being greater than the first coefficient of friction.In examples:• the second coefficient of friction is within the range of 0.1 -1.1 or within the range of 0.2-1 ;• the second coefficient of friction is within the range of 0.6- 1.1 or 'ithin the range of 0.7-1 or within the range of 0.8-1;• the second coefficient of friction is within the range of 0.1-0.7 or w'ithin the range of 0.2-0.6;• the body of the strap is bifurcated;• the body of the strap is formed at least partially from a first material, the first material being a textile material, the first surface portion being formed at least partially by the first material;• the interior of the body of the strap is formed from foam;• the second surface portion is transparent;• the second surface portion extends along the length of the body of the strap;• the second surface portion is positioned centrally with respect to the width of the body of the strap and the user-facing surface comprises a pair of first surface portions extending parallel to the second surface portion on opposite adjacent sides of the second surface portion across the w'idth of the strap;• the user-facing surface is formed by a plurality of second surface portions extending along the length of the body of the strap, the second surface portions being separated across the width of the body of the strap by a plurality of first surface portions;• the plurality of second surface portions comprises one second surface portion provided centrally with respect to the width of the body of the strap and a pair of second surface portions provided at opposite edges of the width of the strap;• the pair of second surface portions provided at opposite edges of the width of the strap are narrower than the second surface portion provided centrally;• the second surface portion is formed at least partially by a second material different to the first material;• the second material is an elastomeric material;• the second material is silicone;• the second material is rubber:• the second material is woven into the first material;• the second material comprises a TPU yam;• the second material is coated over the first material to form a coated area;• the second material is coated over the first material and the user-facing surface comprises a plurality of second surface portions each in the form of a coated area;• the coated area is circular;• the user-facing surface comprises a group of coated areas forming a circle;• the user-facing surface comprises a plurality of groups of coated areas;• each group of coated areas is spaced from an adjacent group of coated areas by a first surface portion;• each group of coated areas expands across substantially the full width of the body of the strap and is spaced from an adjacent group of coated areas along the length of the body of the strap by a first surface portion;• each group of coated areas has a dimension aligned with the width of the body of the strap, said dimension being greater than or equal to half the width of the body of the strap;• each group of coated areas has a dimension aligned with the width of the body of the strap, said dimension being less than half the width of the body of the strap;• the user-facing surface comprises a group of coated areas extending along the length of the body of the strap;• the group is located centrally with respect to the width of the body of the strap and spaced from opposite edges of the body of the strap by first surface portions;• the user-facing surface comprises a group of coated areas in the form of a bullseye pattern;• the user-facing surface comprises a plurality of groups of coated areas each in the form of a bullseye pattern;• the bullseye pattern has a diameter greater than or equal to half of the width of the body of the strap;• the bullseye pattern has a diameter less than half the width of the body of the strap;• the bullseye pattern has a diameter less than or equal to a third of the width of the body of the strap; and / or• the user-facing surface comprises a group of coated areas forming a rectangle.

[0043] Another aspect of the present technology is a positioning and stabilising structure for a patient interface for treatment of sleep disordered breathing, the positioning and stabilising structure comprising a strap according to any one of the aspects or examples above.

[0044] 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.

[0045] 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.

[0046] Another aspect of one form of the present technology is a method of assembling a modular system comprising selecting a positioning and stabilisingstructure, and connecting the positioning and stabilising structure to either a first cushion or a second cushion.

[0047] 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.

[0048] Of course, portions of the aspects may form sub-aspects of the present technology. Also, various ones of the sub-aspccts and / or aspects may be combined in various manners and also constitute additional aspects or sub-aspects of the present technology.

[0049] Other features of the technology will be apparent from consideration of the information contained in the following detailed description, abstract, drawings and claims.4 BRIEF DESCRIPTION OF THE DRAWINGS

[0050] 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:4.1 RESPIRATORY THERAPY SYSTEMS

[0051] Fig. 1A 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.

[0052] 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.

[0053] 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.4.2 RESPIRATORY SYSTEM AND FACIAL ANATOMY

[0054] Fig. 2A 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] Fig. 2G shows a side view of the superficial features of a nose.

[0061] 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.

[0062] 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.

[0063] Fig. 21 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.

[0064] 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.

[0065] Fig. 2L shows an anterolateral view of a nose.4.3 PATIENT INTERFACE

[0066] Fig. 3A shows a patient interface in the form of a nasal mask in accordance with one form of the present technology.

[0067] Fig. 3B shows a patient interface having conduit headgear, in accordance with one form of the present technology.4.4 RPT DEVICE

[0068] Fig. 4A shows an RPT device in accordance with one form of the present technology.

[0069] Fig. 4B is a schematic diagram of the pneumatic path of an RPT device in accordance with one form of the present technology. The directions of upstream and downstream are indicated with reference to the blower and the patient interface. The blower is defined to be upstream of the patient interface and the patient interface is defined to be downstream of the blower, regardless of the actual flow direction at any particular moment. Items which are located within the pneumatic path between the blower and the patient interface are downstream of the blower and upstream of the patient interface.4.5 HUMIDIFIER

[0070] Fig. 5A shows an isometric view of a humidifier in accordance with one form of the present technology.

[0071] 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 5130.4.6 BREATHING WAVEFORMS

[0072] Fig. 6 shows a model typical breath waveform of a person while sleeping.4.7 MODULARITY

[0073] Fig. 7A shows a perspective view of a cushion of a patient interface configured to be worn by a patient and convey pressurized air to the patient’s nose and the patient’s mouth.

[0074] Fig. 7B shows a perspective view of a cushion of a patient interface configured to be worn by a patient and convey pressurized air to the patient’s nose.

[0075] Fig. 7C shows a perspective view of tubes usable with either the cushion of Fig. 7 A or the cushion of Fig. 7B.

[0076] Fig. 7D shows a perspective view of rigidiser aims usable with either the cushion of Fig. 7 A of the cushion of Fig. 7B.

[0077] Fig. 7E shows a perspective view of headgear straps usable with the cushion of Fig. 7 A.

[0078] Fig. 7F shows a perspective view of headgear straps usable with the cushion of Fig. 7B.

[0079] Fig. 7G shows a front view of a pair of sleeves that is removably fitted to either the tubes of Fig. 7C or the rigidiser arms of Fig. 7D.

[0080] Fig. 7H shows a front view of a full sleeve that is removably fitted to the rigidiser arms of Fig. 7D.

[0081] Fig. 71 shows a front perspective view of yet another alternate form of a full sleeve that is removably fitted to the rigidiser arms of Fig. 7D.

[0082] Fig. 7J is a front view of a patient wearing the cushion of Fig. 7A connected to the tubes of Fig. 7C, the headgear straps of Fig. 7E, and the sleeves of Fig. 7G.

[0083] Fig. 7K is a front view of a patient wearing the cushion of Fig. 7A connected to the rigidiser aims of Fig. 7D, the headgear straps of Fig. 7E, and the sleeve of Fig. 7H.

[0084] Fig. 7L is a front view of a patient wearing the cushion of Fig. 7B connected to the conduit headgear of Fig. 7C, and the headgear straps of Fig. 7F.

[0085] Fig. 7M is a front view of a patient wearing the cushion of Fig. 7B connected to the rigidisier arms of Fig. 7D, the headgear straps of Fig. 7F, and the sleeve of Fig. 71.

[0086] Fig. 7N is an isolated perspective view of the vent of Fig. 7L.

[0087] Fig. 70 is an isolated perspective view of a portion of the air circuit ofFig. 7M.

[0088] Fig. 7P is a schematic view illustrating the possible combinations of the patient interfaces.

[0089] Fig. 8A is a patient interface according to an example of the present technology.

[0090] Fig. 8B is a strap according to an example of the present technology.

[0091] Fig. 8C is a strap according to another example of the present technology.

[0092] Figs. 9A-9N are schematic views of straps according to examples of the present technology.5 DETAILED DESCRIPTION OF EXAMPLES OF THETECHNOLOGY

[0093] 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.

[0094] 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.5.1 THERAPY

[0095] 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.

[0096] 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.

[0097] In certain examples of the present technology, mouth breathing is limited, restricted or prevented.5.2 RESPIRATORY THERAPY SYSTEMS

[0098] In one form, the present technology comprises a respiratory therapy system for treating a respirator}' 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 or 3800.5.3 PATIENT INTERFACE

[0099] A non-invasive patient interface 3000, such as that shown in Fig. 3A, in accordance with one aspect of the present technology comprises the followingfunctional 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 some forms, 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 scaled patient interface 3000 is therefore suitable for delivery of positive pressure therapy.

[0100] As shown in Fig. 3B, a non-invasive patient interface 3000 in accordance with another 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 and one form of connection port 3600 for connection to an air circuit (such as the air circuit 4170 shown in Figs. 1A-1C). The plenum chamber 3200 may be formed of one or more modular components (c.g., a cushion module 3150 together with the seal-forming structure 3100) in the sense that it or they can be replaced with different components, for example components of a different size.

[0101] 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.

[0102] 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.5.3.1 Seal-forming structure

[0103] 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 thepatient interface was placed on the face, tension in the positioning and stabilising structure and the shape of a patient’s face.

[0104] In one form the target seal-forming region is located on an outside surface of the seal-forming structure 3100.

[0105] In certain forms of the present technology, the seal-forming structure 3100 is constructed from a biocompatible material, e.g. silicone rubber.

[0106] A seal-forming structure 3100 in accordance with the present technology may be constructed from a soft, flexible, resilient material such as silicone.

[0107] 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.5.3.1.1 Sealing mechanisms

[0108] 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.5.3.1.2 Nose bridge or nose ridge region

[0109] 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.

[0110] 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.5.3.1.3 Upper lip region

[0111] 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.

[0112] 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.5.3.1.4 Chin-region

[0113] Tn 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.

[0114] Tn 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.5.3.1.5 Forehead region

[0115] 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.5.3.1.6 Nasal pillows

[0116] Tn 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.5.3.1.7 Nose-only Masks

[0117] 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.

[0118] 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 pronasalc, 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.

[0119] 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. In one form, for example as shown in Fig. 3B, the seal-forming structure 3100 is configured to form a seal in use with inferior surfaces of the nose around the nares. 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 structure 3100 may comprise a single opening to provide a flow or air or breathable gas to both of the patient’s nares.

[0120] In some forms, a nose-only mask may comprise nasal pillows, described above.5.3.1.8 Nose and Mouth Masks

[0121] 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.

[0122] One form of nosc-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 includethe 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”.

[0123] 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 for delivering 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.

[0124] 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.

[0125] 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.

[0126] 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.5.3.2 Plenum chamber

[0127] 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.5.3.2.1 Multiple Openings

[0128] As shown in Figs. 7A and 7B, different plenum chambers 3200-1, 3200-2 may be formed as part of a multi-opening cushion 3050-1, 3050-2. In the illustrated examples, the cushions 3050-1, 3050-2 each include three openings, although an alternate cushion may be formed with greater or fewer openings.

[0129] In some forms, the different openings may serve different functions. For example, some openings may be exclusively inlet openings, while other openings may be exclusively outlet openings.

[0130] In other forms, at least one opening may serve two different functions. For example, one opening may operate as both an inlet and an outlet during the same breathing cycle.

[0131] The plurality of openings may allow for a variety of configurations of air delivery to the plenum chamber 3200-1, 3200-2. For example, depending on patient need and / or patient comfort, the patient may use a given cushion 3050-1 , 3050-2 in a “tube-up” configuration (e.g., using conduit headgear - described below) or a “tubedown” configuration (e.g., using a single conduit in front of the patient’s face).5.3.2.1.1 Nose and Mouth Mask

[0132] As shown in Fig. 7A, the plenum chamber 3200-1 includes a pair of plenum chamber inlet ports 3254-1, which may be used to convey gas into and / or out of the plenum chamber 3200-1. The plenum chamber inlet ports 3254-1 may be disposed on opposite sides (e.g., left and right sides) of the plenum chamber 3200-1 .

[0133] In some forms, the plenum chamber 3200-1 may also include at least one vent opening 3402-1 (see e.g., Fig. 7 A). The vent opening 3402-1 may be disposed ina center of the plenum chamber 3200-1. For example, the vent opening 3402-1 may be disposed between the plenum chamber inlet ports 3254-1 .

[0134] In some forms, the plenum chamber 3200-1 may include a pair of grooves 3266-1 . Each groove 3266-1 may be disposed proximate to one of the plenum chamber inlet ports 3254-1. Each groove 3266-1 may form a partially recessed surface.5.3.2.1.2 Nose-only Mask

[0135] The plenum chamber 3200-2 of a nasal only cushion 3050-2 may be similar to the plenum chamber 3200-1 of the mouth and nose cushion 3050-1. Only some similarities and differences between the plenum chambers 3200-1, 3200-2 may be described below.

[0136] As shown in Fig. 7B, the plenum chamber 3200-2 includes a pair of plenum chamber inlet ports 3254-2, which may be used to convey gas into and / or out of the plenum chamber 3200-2. The plenum chamber inlet ports 3254-2 may be disposed on opposite sides (c.g., left and right sides) of the plenum chamber 3200-2.

[0137] In some forms, the plenum chamber 3200-2 may also include at least one vent opening 3402-2 (see e.g., Fig. 7B). The vent opening 3402-2 may be disposed in a center of the plenum chamber 3200-2. For example, the vent opening 3402-2 may be disposed between the plenum chamber inlet ports 3254-2.

[0138] In some forms, the plenum chamber 3200-2 may include a pair of grooves 3266-2. Each groove 3266-2 may be disposed proximate to one of the plenum chamber inlet ports 3254-2. Each groove 3266-2 may form a partially recessed surface.5.3.3 Positioning and stabilising structure

[0139] The seal-forming structure 3100 of the patient interface 3000 of the present technology may be held in sealing position in use by the 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. 3A and 3B.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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 isporous 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.

[0148] In certain forms of the present technology, a positioning and stabilising structure 3300 comprises a strap that is extensible, e.g. resiliency 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.

[0149] 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.

[0150] 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 tic 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.

[0151] 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.

[0152] 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.

[0153] 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,

[0154] 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.5.3.3.1 Conduit headgear5.3.3.1.1 Conduit headgear tubes

[0155] In some forms of the present technology, the positioning and stabilising structure 3300 comprises one or more headgear tubes 3350 that deliver pressurised air received from a conduit forming part of the air circuit 4170 from the RPT device to the patient’s airways, for example through the plenum chamber 3200 and sealforming structure 3100. In the form of the present technology illustrated in Fig. 3B, the positioning and stabilising structure 3300 comprises two tubes 3350 that deliver air to the plenum chamber 3200 from the air circuit 4170. The tubes 3350 are configured to position and stabilise the seal-forming structure 3100 of the patient interface 3000 at the appropriate part of the patient’s face (for example, the nose and / or mouth) in use. This allows the conduit of air circuit 4170 providing the flow of pressurised air to connect to a connection port 3600 of the patient interface in a position other than in front of the patient’s face, for example on top of the patient’s head.

[0156] The tubes 3350 may be formed from a flexible material, such as an elastomer, e.g. silicone or TPE, and / or from one or more textile and / or foam materials. The tubes 3350 may have a preformed shape and may be able to be bent or moved into another shape upon application of a force but may return to the original preformed shape in the absence of said force. The tubes 3350 may be generally arcuate or curved in a shape approximating the contours of a patient’s head between the top of the head and the nasal or oral region.

[0157] Each tube 3350 may be configured to receive a flow of air from the connection port 3600 on top of the patient’s head and to deliver the flow of air to the seal-forming structure 3100 at the entrance of the patient’s airways. In the example shown in Fig. 3B, each tube 3350 lies in use on a path extending from the plenum chamber 3200 across the patient’s cheek region and superior to the patient’s ear to the elbow 3610. For example, a portion of each tube 3350 proximate the plenum chamber 3200 may overlie a maxilla region of the patient’s head in use. Another portion of each tube 3350 may overlie a region of the patient’s head superior to an otobasion superior of the patient’s head. Each of the tubes 3350 may also lie over the patient’s sphenoid bone and / or temporal bone and either or both of the patient’s frontal bone and parietal bone. The elbow 3610 may be located in use over the patient’s parietalbone, over the frontal bone and / or over the junction therebetween (e.g. the coronal suture).

[0158] As described above, in some examples of the present technology the patient interface 3000 comprises a seal-forming structure 3100 in the form of a cradle cushion which lies generally under the nose and seals to an inferior periphery of the nose (e.g. an under-the-nose cushion). The positioning and stabilising structure 3300, including the tubes 3350 may be structured and arranged to pull the seal-forming structure 3100 into the patient’s face under the nose with a scaling force in a posterior and superior direction (e.g. a postero superior direction). A sealing force with a posterosuperior direction may cause the seal-forming structure 3100 to form a good seal to both the inferior periphery of the patient’s nose and anterior- facing surfaces of the patient’s face, for example on either side of the patient’s nose and the patient’s lip superior.5.3.3.1.2 Extendable and non-extendable tube portions

[0159] In some examples of the present technology, one or both of the tubes 3350 are not extendable in length. However, in some forms, the tubes 3350 may comprise one or more extendable tube sections, for example formed by an extendable concertina structure. In some forms, the patient interface 3000 may comprise a positioning and stabilising structure 3300 including at least one gas delivery tube comprising a tube wall having an extendable concertina structure. The patient interface 3000 shown in Fig. 3B comprises tubes 3350, the superior portions of which comprise extendable tube sections each in the form of an extendable concertina structure 3362. Each tube 3350 may comprise a non-extendable tube section 3363 inferior of the extendable concertina structure 3362.5.3.3.1.3 Conduit headgear connection port

[0160] In certain forms of the present technology, the patient interface 3000 may comprise a connection port 3600 located proximal to a superior, lateral or posterior portion of a patient’s head. For example, in the form of the present technology illustrated in Fig 3B, the connection port 3600 is located on top of the patient’s head (e.g. at a superior location with respect to the patient’s head). In this example the patient interface 3000 comprises an elbow 3610 forming the connection port 3600. The elbow 3610 may be configured to fluidly connect with a conduit of an air circuit 4170. The elbow 3610 may be configured to swivel with respect to the positioning and stabilising structure 3300 to at least partially decouple the conduit from thepositioning and stabilising structure 3300. In some examples the elbow 3610 may be configured to swivel by rotation about a substantially vertical axis and, in some particular examples, by rotation about two or more axes. In some examples the elbow may comprise or be connected to the tubes 3350 by a ball-and-socket joint. The connection portion 3600 may be located in the sagittal plane of the patient’s head in use.5.3.3.1.4 Headgear Tube Fluid Connections

[0161] The two tubes 3350 arc fluidly connected at their inferior ends to the plenum chamber 3200. In certain forms of the technology, the connection between the tubes 3350 and the plenum chamber 3200 is achieved by connection of two rigid connectors. The tubes 3350 and plenum chamber 3200 may be configured to enable the patient to easily connect the two components together in a reliable manner. The tubes 3350 and plenum chamber 3200 may be configured to provide tactile and / or audible feedback in the form of a ‘re-assuring click’ or a similar sound, so that the patient may easily know that each tube 3350 has been correctly connected to the plenum chamber 3200. In one form, the tubes 3350 are formed from a silicone or textile material and the inferior end of each of the silicone tubes 3350 is overmolded to a rigid connector made, for example, from polypropylene, polycarbonate, nylon or the like. The rigid connector on each tube 3350 may comprise a female mating feature configured to connect with a male mating feature on the plenum chamber 3200. Alternatively, the rigid connector on each tube 3350 may comprise a male mating feature configured to connect to a female mating feature on the plenum chamber 3200. In other examples the tubes 3350 may each comprise a male or female connector formed from a flexible material, such as silicone or TPE, for example the same material from which the tubes 3350 are formed.S.3.3.2 Headgear straps

[0162] 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).

[0163] 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. Althoughthe textile may include rigidisers along a selected length, which may limit bending, flexing, and / or stretching of the headgear 3302.

[0164] 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.

[0165] Two forms of the headgear, four-point headgear 3302-1 and two-point headgear 3302-2, are discussed in more detail below as illustrative examples.5.3.3.2.1 Four-point connection

[0166] As shown in Fig. 7E, 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.

[0167] In some forms, the headgear 3302-1 may include inferior straps 3304-1, which may connect to an inferior portion of the cushion 3050-1. The inferior straps3304-1 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.

[0168] The headgear 3302-1 may also include superior straps 3305-1, which may overlay the temporal bones, parietal bone, and / or occipital bone. The superior straps3305-1 may also connect to the tubes 3350 (c.g., by interfacing with the tabs 3320).

[0169] 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.

[0170] 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.

[0171] In some forms, the inferior straps 3304-1 arc 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 3200, but the length of the inferior straps 3304-1 may not be affected.

[0172] In some forms, the superior straps 3305-1 may be connected directly to the tabs 3320 of the tubes 3350. The superior straps 3305-1 may be threaded through the tabs 3320 in order to adjust the length and control the tensile force of each superior strap 3305-1 .

[0173] In some forms, the headgear 3302-1 may be used only with the nose and mouth cushion 3050-1 (e.g., because the nose-only cushion 3050-1 does not have four connection points). However, the headgear 3302-1 may be used interchangeably with the tubes 3350 and the rigidiscr arms 3340.5.3.3.2.2 Two-point connection

[0174] As shown in Fig. 7F, some forms of the headgear 3302-2 may be a two- point connection headgear. This means that the headgear 3302-2 may connect to two separate places.

[0175] In some forms, the headgear 3302-2 may be formed from a continuous piece of material. In other words, the headgear 3302-2 may not be formed from multiple straps connected (e.g., stitched) together. This may be comfortable for a patient as they will not be in contact with any seams or joints connecting different straps. In other forms, the headgear 3302-2 may be formed from multiple straps (e.g., two superior straps, a rear strap, etc.) that are connected together (e.g., with stitching, ultra-sonic welding, etc.).

[0176] In certain forms of the present technology, the positioning and stabilising structure 3300 comprises at least one headgear strap acting in addition to the tubes 3350 to position and stabilise the seal-forming structure 3100 at the entrance to the patient’s airways. As shown in Fig. 3B, the patient interface 3000 comprises a strap 3307-2 forming part of the positioning and stabilising structure 3300. The strap 3307- 2 may be known as a back strap or a rear headgear strap, for example. The rear strap 3307-2 may overlay the temporal bones, parietal bone, and / or occipital bone. In other examples of the present technology, one or more further straps may be provided. For example, patient interfaces 3000 according to examples of the present technology having a nose-and-mouth cushion may have a second, lower, strap configured to lie against the patient’s head proximate the patient’s neck and / or against posterior surfaces of the patient’s neck.

[0177] In the example shown in Fig. 3B, strap 3310 of the positioning and stabilising structure 3300 is connected between the two tubes 3350 positioned on each side of the patient’s head and passing around the back of the patient’s head, for example overlying or lying inferior to the occipital bone of the patient’s head in use. The strap 3310 connects to each tube above the patient’s ears. With reference to Fig. 3B, the positioning and stabilising structure 3300 comprises a pair of tabs 3320. In use a strap 3310 may be connected between the tabs 3320. The strap 3310 may be sufficiently flexible to pass around the back of the patient’s head and lie comfortably against the patient’s head, even when under tension in use.

[0178] As shown in Fig. 7F, some forms of the headgear 3302-2 may be at least partially bifurcated. For example, a rear strap 3307-2 of the headgear 3302-2 (e.g., configured to contact the posterior portion of the patient’s head) may be wider than the surrounding portions of the headgear 3302-2. An intermediate section 3308-2 of the rear strap 3307-2 may include a slit 3309-2. A superior section of the rear strap 3307-2 may therefore be movable relative to the inferior section as a result of the slit 3309-2. This may allow the patient to have a larger strap coverage on the posterior region of their head, which may assist in better anchoring the headgear 3302-2 to the patient’s head since there is no inferior strap (e.g., 3304-1).

[0179] In some forms, the headgear 3302-2 may be used only with the nasal cushion 3050-2 (e.g., because the nose and mouth cushion 3050-1 does not have four connection points). However, the headgear 3302-2 may be used interchangeably with the tubes 3350 and the rigidiser arms 3340.5.3.3.2.3 Strap construction

[0180] Fig. 8A shows a patient interface 3000 according to one example of the present technology. The patient interface 3000 comprises components as disclosed elsewhere herein, including a plenum chamber 3200, seal-forming structure 3100, positioning and stabilising structure 3300, vent 3400 and connection port 3600. The positioning and stabilising structure 3300 comprises conduit headgear tubes 3350 in this example, along with a strap 3310. In this example the strap 3310 is constructed and arranged to overlie the posterior of the user’s head, connecting between the conduit headgear tubes 3350. Fig. 8B shows the strap 3310 in isolation.

[0181] Fig. 8C shows a strap 3310 according to another example of the present technology, being a bifurcated strap. This bifurcated strap 3310 may replace the strap shown in Fig. 8A.

[0182] The straps 3310 shown in Figs. 8A-8C and in other examples of the present technology form part of a positioning and stabilising structure 3300 for a patient interface 3000. The positioning and stabilising structure 3300 may be configured to provide a force to hold a seal-forming structure of the patient interface in a therapeutically effective position on the patient’s head during use of the patient interface for treatment of sleep disordered breathing.

[0183] The strap 3310 may comprise a body 3313 (e.g. the material and structure forming the strap 3310. The body 3313 may have a length, a width transverse to the length, and a pair of end portions 3315 at opposite ends of the length. The end portions 3315 may be constructed and arranged to connect to a portion of the patient interface 3000 in use. For example, the end portions 3315 may connect to one or more components of the patient interface 3000 or of a positioning and stabilising structure 3300 thereof. The strap 3310 may then form part of the patient interface 3000. In some examples the end portions 3315 may be passed through slots or buckles and may be looped back and secured to the body 3313 of the strap 3310, for example with a hook-and-loop connection. In other examples an end portion 3315 may form a mechanical connection such as a releasable snap fit with a component of the patient interface 3000 or positioning and stabilising structure 3300 thereof, such as with a snap connector or other press fit connector. In further examples an end portion 3315may be secured to the body 3313 of a strap 3310 by another means, such as with a magnetic connection or a buckle, such as a ladder lock buckle.

[0184] In some forms of the present technology, the body 3313 of the strap 3310 comprises a user-facing surface configured to engage the user’s hair and / or skin in use, the user-facing surface having a first surface portion 3311 and a second surface portion 3312, the first surface portion 3311 providing a first coefficient of friction between the strap 3310 and the user’s hair or skin, the second surface portion 3312 providing a second coefficient of friction between the strap 3310 and the user's hair or skin., The second coefficient of friction may be greater than the first coefficient of friction. The strap 3310 may be formed partially or mostly by material forming the first surface portion(s) 331 1 and which provides the strap 3310 with desirable overall properties such as elasticity, strength, appearance and low friction providing for a comfortable feel. However, advantageously, the strap 3310 may also comprise one or more second surface portions 3312 providing for higher friction than would be provided by the first surface portion(s) alone. The second surface portions 3312 may help hold the strap 3310 in place, helping prevent it from moving (e.g. slipping off or riding up / down) on the user’s hair or skin, or at least do so under a wider range of disruptive forces than the strap 3310 would otherwise be able to withstand without higher friction second surface portions 3312. This may advantageously provide for a comfortable yet stable patient interface 3000.

[0185] In some examples, the second coefficient of friction may be within the range of 0.1 -1.1 or within the range of 0.2-1. The actual amount of friction desired in a strap 3310 of a particular patient interface 3000 may depend on the overall design of the positioning and stabilising structure 3300 and patient interface 3000, as well as the size of the positioning and stabilising structure 3300 and user preference. For example, a positioning and stabilising structure 3300 comprising a single strap 3310 may benefit from higher added friction than a positioning and stabilising structure 3300 comprising multiple straps 3310.

[0186] It is to be understood that the features of the straps 3310 disclosed herein may be provided to any strap portion of a positioning and stabilising structure 3300, including but not limited to straps engaging the user’s head proximate the parietalbones, proximate the occipital bone or lying against the user’s head proximate the temporal bones, by way of example only.

[0187] In some examples, the second coefficient of friction may be within the range of 0.6-1 .1 or within the range of 0.7-1 or within the range of 0.8-1 . These options may be applied in straps 3310 intended to provide for high friction.

[0188] In further examples the second coefficient of friction is within the range of 0.1-0.7 or within the range of 0.2-0.6.

[0189] The actual coefficient of friction within the exemplary ranges above for a patient at a particular time may depend on how much moisture is present, hair style, personal skin and hair properties, and the like. Furthermore, the actual friction between a strap 3310 and the user will depend on the amount of second surface portion 3312 area on the strap 3310 in comparison to the area of the first surface portion 331 1. Various exemplary' designs are disclosed below by way of example. Some designs provide for higher friction than others. More area of the strap 3310 formed by the second surface portion(s) 3312 may provide for higher friction than if less area of the strap 3310 is formed by the second surface portion(s) 3312.

[0190] In some examples, the body of the strap 3310 is formed at least partially from a first material, the first material being a textile material (e.g. knitted, woven or the like). The first surface portion 3311 may be formed at least partially by the first material. The first material may, in examples, be one or more of polyester, elastane, Nylon, polypropylene or the like. The first material forming the first surface portion 3311 may be a blend of materials, for example nylon and elastane. In some examples the first material is elastic and the strap 3310 is elastically extendable.

[0191] In some examples, the interior of the body 3313 of the strap 3310 is formed from foam. The foam may be covered on both sides by the first material. In other examples the strap 3310 may be formed by one, two, or more layers of textile material.

[0192] In some examples, the second surface portion 3312 is transparent. This may advantageously make the second surface portion 3312 less conspicuous and, for examples in which the first material is a textile material, may help maintain the textileappearance of the strap 3310. Textiles may provide for an appearance closer to bedclothes than a medical device, which may encourage patient compliance due to greater actual or perceived comfort associated with a patient interface 3000 having the appearance of bedclothes in comparison to a patient interface 3000 having the appearance of a medical device.

[0193] In some forms of the present technology, the second surface portion 3312 is formed at least partially by a second material different to the first material. In some examples, the second material is an elastomeric material. For example, the second material may be silicone, rubber, a thermoplastic elastomer (TPE) or another elastomer or material behaving like an elastomer. In some examples the second material may be a thermoplastic polyurethane (TPU). The second material in some forms is elastically extendable (e.g. stretchable). Advantageously, such a second material may not prevent the first material from extending. That is, both the first material and the second material may be elastically extendable to provide for an elastically extendable strap 3310 which also has the non-slip / increased friction properties provided by the addition of the second material to first material.5.3.3.2.3.1 Second surface portions

[0194] Figs. 9A-9N show schematic representations of user-facing surfaces of straps 3310 according to examples of the present technology.

[0195] In some examples, such as the examples shown in Figs. 9A, 9B, 9C, 9G, 91 and 9N, the second surface portion 3312 extends along the length of the body 3313 of the strap 3315. As shown in Figs. 9A and 91 for example, the second surface portion 3312 is positioned centrally with respect to the width of the body 3313 of the strap 3310 and the user-facing surface comprises a pair of first surface portions 3311 extending parallel to the second surface portion 3312 on opposite adjacent sides of the second surface portion 3312 across the width of the strap 3310. In some examples the strap 3310 may comprise first surface portions 3311 along the edges of the body 3313 of the strap, which may have a width of l-5mm, for example within the range of 2- 3mm.

[0196] In the examples shown in Figs. 9B, 9C and 9G, the user-facing surface is formed by a plurality of second surface portions 3312 extending along the length ofthe body 3313 of the strap 3310. In these examples the second surface portions 3312 are separated across the width of the body 3313 of the strap 3310 by a plurality of first surface portions 3311. Fig. 9N shows a similar arrangement in which two second surface portions 3312 are separated by a single first surface portion 331 1 across the width dimension of the strap 3310. The examples shown in Figs. 9B, 9C and 9G may provide for straps 3310 with higher friction, while the example in Fig. 9N may provide for a strap 3310 with lower friction, as less area is occupied by the second material. For the same reason, Figs. 9A-9I show straps 3310 providing high friction while Figs. 9J-9N show' straps 3310 providing low'er friction.

[0197] In some examples, the plurality of second surface portions 3312 comprises one second surface portion 3312 provided centrally with respect to the width of the body 3313 of the strap 3310 and a pair of second surface portions 3312 provided at opposite edges of the width of the strap 3310. Such an example is shown in Fig. 9C. The pair of second surface portions 3312 provided at opposite edges of the width of the strap 3310 may be narrower than the second surface portion 3312 provided centrally.

[0198] In some forms of the present technology, the second material is woven into the first material. In examples, the second material may be in the form of yam, cord or thread, such as silicone yam, cord or thread, or rubber yam, cord or thread. Alternatively the second material may be a TPE yam, cord or thread, or a TPU yam, cord or thread. The TPU yarn may be an elastic TPU yarn. The second material may be knitted or woven into the first material. Figs. 9A, 9B and 9C show examples of straps 3310 in which the second surface portions 3312 are formed by weaving of the second material together or into the first material. In some examples, the second material may comprise a TPU yarn, such as Mobilon™ yarn, incorporated into the knitting or weaving process used to form the strap 3310. Straps 3310 according to the present technology having Mobilon™ yam or other TPU, silicone, TPE or other elastomeric yarn incorporated into the knitting or weaving process may advantageously have good non-slip performance, good elasticity and high durability.

[0199] In some forms of the technology, the second material is coated over the first material to form a coated area. The coated area then becomes a second surface portion 3312. Figs. 9D-9N depict straps 3310 constructed in this way.

[0200] Fig. 91 depicts an example of a strap 3310 having a second surface portion 3312 which may be either coated with a second material or formed by weaving of second material into the first material.

[0201] In some forms, a strap 3310 may comprise at least one second surface portion 3312 formed by weaving of a second material into the first material, and at least one second surface portion 3312 formed by coating a second material over the first material.

[0202] In some examples, the user-facing surface of the strap 3310 comprises a plurality of second surface portions 3312 each in the form of a coated area. In some examples, such as the straps 3310 in Figs. 9G and 9N, each coated area is a strip extending along a length of the strap 3310. In other examples, the coated areas may take other shapes. For example, Figs. 9D, 9E, 9F, 9K, 9L and 9M show straps 3310 having one or more second surface portions 3312 in the form of a coated area that is circular'.

[0203] In some examples, such as the straps 3310 shown in Figs. 9D-9F, the user-facing surface comprises a plurality of groups of coated areas. In the example shown in Fig. 9D, each group of coated areas expands across substantially the full width of the body 3313 of the strap 3310 and is spaced from an adjacent group of coated areas along the length of the body 3313 of the strap 3310 by a first surface portion 331 1. In the straps 3310 shown in Figs. 9E and 9F, the user-facing surface comprises a group of coated areas extending along the length of the body 3313 of the strap. In these examples, the group is located centrally with respect to the width of the body 3313 of the strap 3310 and spaced from opposite edges of the body 3313 of the strap 3310 by first surface portions 3311. The strap 3310 shown in Fig. 9F may have a greater number of smaller coated areas than the example shown Fig. 9E but both may have a similar total area coated by the second material may both provide for high friction in use.

[0204] In some examples of the present technology, the user-facing surface comprises a group of coated areas in the form of a bullseye pattern. The group of coated areas may be a plurality of coated unfilled concentric circles of differing diameter, with a small, filled circle in the middle, forming a bullseye shape. In thestraps 3310 shown in Figs. 9H and 9J, the user-facing surface comprises a plurality of groups of coated areas each in the form of a bullseye pattern. The strap 3310 shown in Fig. 9H has larger bullseyes and therefore larger coated areas than the strap 3310 shown in Fig. 9J, to provide a strap 3310 having a higher friction level than that shown in Fig. 9J. In some examples the bullseye pattern has a diameter greater than or equal to half of the width of the body 3313 of the strap 3310. In other examples, the bullseye pattern has a diameter less than half the width of the body of the strap 3310. As shown in Fig. 9J for example, the bullseye pattern has a diameter less than or equal to a third of the width of the body 3313 of the strap 3310.

[0205] In some examples, such as shown in Figs 9D, 9H, 91, 9K, 9L and 9M, each group of coated areas is spaced from an adjacent group of coated areas by a first surface portion 3311. In some forms, such as the strap 3310 shown in Fig. 9K, the user-facing surface comprises a group of coated areas forming a rectangle. In particular, the user-facing surface comprises a plurality of groups of coated areas. Each coated area is circle but is part of a group forming a rectangular shape.

[0206] In some examples the user-facing surface of the strap 3310 may comprise an alternating scries of first surface portions 3311 and second surface portions 3312. Each of the first surface portions 331 1 may have substantially the same length along the length of the body 3313 of the strap 3310 as the second surface portions 3312. Fig. 9H shows such an example in which each second surface portion 3312 formed by a bullseye shaped group of coated areas is spaced from an adjacent second surface portions 3312 by a first surface portion 3311 having substantially the same size. In some examples, the user-facing surface of the strap 3310 may comprise an alternating scries of first surface portions 3311 and second surface portions 3312, in which the second surface portions 3312 have substantially the same width transversely across the strap 3310 as the first surface portions 3311, but not necessarily the same length. Fig. 9D shows such an example.

[0207] The dimensions of the groups of coated areas may vary between different examples of the present technology. In some forms, such as is shown in Fig. 9K, each group of coated areas has a dimension aligned with the width of the body 3313 of the strap 3310, said dimension being greater than or equal to half the width of the body 3313 of the strap 3310.

[0208] In some examples, such as the example shown in Fig. 9L, each group of coated areas has a dimension aligned with the width of the body 3313 of the strap 3310, said dimension being less than half the width of the body 3313 of the strap 3310. The user- facing surface in some examples comprises a group of coated areas forming a circle. As shown in Figs. 9L and 9M for example, the user-facing surface comprises second surface portions 3312a each in the form of a group of coated areas, the coated areas being small, filled circles. In the Fig. 9L example the user-facing surface also comprises second surface portions 3321b each in the form of a large, filled circles as opposed to a group of smaller filled circles.

[0209] Fig. 9L shows that in some examples, not all of the second surface portions 3312 in a strap 3310 need to be identical. In the Fig. 9L example, the strap 3310 comprises an alternating series of second surface portions 3312a and second surface portions 3312b, each of the second surface portions 3312a being a group of coated areas and each the second surface portions 3312b being a single filled area. Where strap 3310 comprises a plurality of second surface portions 3312 which are not all identical to each other, the second surface portions 3312 do not necessarily need to be alternating types of second surface portions 3312. For example, a strap 3310 may comprise one second surface portion 3312 of a first type, and multiple second surface portions 3312 of a second type. Furthermore, it is to be understood that a second surface portion 3312 may be a single contiguous area of high friction material (e.g. high in comparison to the first material) or may be formed by multiple discrete ar eas of high friction material which together form a second surface portion 3312 as a group.

[0210] In some examples, every second surface portion 3312 of a strap 3310 may have a different configuration (e.g. shape or construction) to every other second surface portion 3312 of the strap 3310. In some examples the second surface portion 3312 may be a company logo, or the strap 3310 may comprise several second surface portions 3312, each being one of the letters of a company or brand name, such that the second surface portions 3312 together spell out the name.S.3.3.3 Rigidiser Arm

[0211] As shown in Fig. 7D, a rigidiser arm 3340 may be an elongated, rigid member that assists in maintaining the cushion (e.g., the nose and mouth cushion3050-1 or the nasal cushion 3050-2) in an operating position. The rigidiser arm 3340 may contact a side of the patient’s head and provide a force to limit slipping of the seal-forming structure 3100 from the patient’s nose and / or mouth.

[0212] In some forms, the rigidiser arm 3340 is constructed from a rigid material (e.g., plastic). The rigid material may not permit the rigidiser aim 3340 to stretch. Additionally, the rigidiser arm 3340 may be substantially inflexible and may be unable to bend. The rigidiser aim 3340 may be pre-molded into a desired shape in order to fit a patient’s head. For example, the rigidiser arms 3340 may be molded with a curved shape to substantially correspond to the shape of the side of the patient’s head (e.g., overlaying the masseter muscle and / or the temporal bone).

[0213] In certain forms, the rigidiser arm 3340 may be molded in order to conform to a specific patient’s head (e.g., the rigidiser arm 3340 is customized).

[0214] In some forms, the rigidiser arm 3340 may be flexible along at least one direction. For example, the rigidiser arm 3340 may be flexible about its width and may be inflexible along its length. In other words, the rigidiser arm 3340 may be bendable about an axis along the width of the rigidiser arm 3340, but may be unable to bend about an axis perpendicular to the rigidiser arm 3340. This may allow an individual patient to adjust the rigidiser arm 3340 in order to better fit their individual head.

[0215] In certain forms, the rigidiser arm 3340 may remain in the new position after being bent. This may allow a patient adjust the shape of the rigidiser arm 3340 for their specific head and then the rigidiser arm 3340 will keep the desired shape while in use in order to promote patient comfort.

[0216] In some forms, a first end 3342 of the rigidiser arm 3340 may be a free end and a second end 3344 (e.g., opposite of the first end 3342) of the rigidiser arm 3340 may be fixed. The first end 3342 may be curved in order to minimize sharp edges that could cause patient discomfort. The first end 3342 may also overlay the patient’s head proximate to the temporal bone, in use. The second end 3344 may be fixed to an arm connection structure 3504.

[0217] In some forms, the arm connection structure 3504 may be similar to the conduit connection structure 3500. For example, the arm connection structure 3504 and the conduit connection structure 3500 may have substantially the same shape. This may allow either the conduit connection structure 3500 or the arm connection structure 3504 to fit into the groove (e.g., 3266-1 or 3266-2) and connect to theplenum chamber inlet port 3254. The arm connection structure 3504 may connect to the nose and mouth cushion 3050-1 or the nose-only cushion 3050-2 in substantially the same way as the conduit connection structure 3500 (e.g., via a snap fit, press fit, friction fit, etc.).

[0218] In some forms, the arm connection structure 3504 may act as a plug for the plenum chamber inlet port 3254 (e.g., either 3254-1 and / or 3254-2). Unlike the tubes 3350, the rigidiser aim 3340 does not convey pressurized air to the plenum chamber 3200. The rigidised arm 3340 may be used with a “tube down” configuration, where a hose is connected to the vent opening 3402 (e.g., either 3402-1 and / or 3402-2), and conveys air into the plenum chamber 3200 through the vent opening 3402. In this example, air does not need to travel into or out of the plenum chamber inlet openings 3254. Thus, the arm connection structure 3504 may form a seal with the plenum chamber inlet opening 3254 in order to limit airflow into or out of the plenum chamber 3200.5.3.4 Vent

[0219] 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.

[0220] 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.

[0221] 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.

[0222] 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.

[0223] As shown in Fig. 7N, a vent 3450 may be used with the patient interface 3000. The vent 3450 may have a substantially similar shape to the vent opening 3402- 1 (e.g., a substantially circular shape).

[0224] The vent 3450 may be used with either the mouth and nose plenum chamber 3200-1 (e.g., illustrated in Figs. 7A) or the nose-only plenum chamber 3200- 2 (e.g., illustrated in Figs. 7B).

[0225] With continued reference to Fig. 7 A, the vent 3450 may include a vent housing 3404, which may be configured to engage with the vent opening 3402. The vent housing 3404 may be constructed from a rigid material or a semi-rigid material. For example, the vent housing 3404 may be constructed from plastic, metal, or any similar material. The vent housing 3404 may add rigidity to the patient interface 3000 (e.g., to limit unwanted bending that may affect the position of the seal-forming structure 3100 on the patient’s face).

[0226] The vent housing 3404 may include an anterior surface 3408, a posterior surface 3412, and a groove 3416. The anterior surface 3408 faces away from the patient’s face in use, and may be positioned outside the pressurized volume of the plenum chamber 3200. The posterior surface 3412 is disposed opposite to the anterior surface 3408. In use, the posterior surface 3412 may face the patient and may be disposed within the pressurized volume of the plenum chamber 3200. The groove 3416 may be formed between the anterior and posterior surfaces 3408, 3412. A portion of the plenum chamber 3200 may be received within the groove 3416 in order to retain the vent 3400 in position.

[0227] In some forms, a diffuser 3448 may be used with the vent housing 3404. The diffuser 3448 may assist with limiting the decibel output from any of the patient interface 3000 (or any other patient interface). Specifically, the diffuser 3448 may assist in limiting the decibel level associated with air output from the patient interface 3000 (e.g., exhaled air), although the diffuser 3448 may limit the decibel level of at any point in the patient interface.

[0228] In certain forms, the diffuser 3448 may diffuse, and therefore slow, the exhaust gas exiting the plenum chamber 3200 and passing through the vent housing 3404. The diffuser 3448 may assist in avoiding jetting and associated discomfort to the patient and / or bed partner (e.g., noise caused by jetting against a pillow, sheets, bedclothes, etc.).

[0229] In some forms, the diffuser may include an anterior surface 3456 that faces away from the patient in use. An outer diameter of the anterior surface 3456 may be less than an inner diameter of the vent housing 3404 proximate to the anterior surface 3408. This may form a gap 3464 through which air may travel.5.3.5 Decoupling structure(s)

[0230] Tn one form the patient interface 3000 includes at least one decoupling structure, for example, a swivel or a ball and socket.5.3.6 Connection port

[0231] Connection port 3600 allows for connection to the air circuit 4170.5.3.7 Forehead support

[0232] In one form, the patient interface 3000 includes a forehead support 3700.5.3.8 Anti-asphyxia valve

[0233] In one form, the patient interface 3000 includes an anti-asphyxia valve.5.3.9 Ports

[0234] 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.5.3.10 Modularity

[0235] As described above, the cushion, headgear, and sleeves may come in different styles, which may correspond to different uses (e.g., mouth breathing, nasal breathing, etc.). A patient or clinician may select certain combinations of cushions, headgear, and sleeves in order to optimize the effectiveness of the therapy and / or the individual patient’ s comfort. An example of this sort of modular design is described in PCT / SG2022 / 050777 filed 28 October 2022, incorporated herein by reference in its entirety.

[0236] In some forms, the different styles of cushions, headgear, and sleeves may be used interchangeably with one another in order to form different combinations of patient interfaces. This may be beneficial from a manufacturing prospective because wider variety of patient interfaces may be created using fewer parts. Additionally or alternatively, the various combinations may allow a patient to change styles of patient interface without changing the every component.

[0237] Air may be delivered to the patient in one of two main ways. In one example, the patient may receive the flow of pressurized air through headgear tubes 3350 (see e.g., Fig. 3B). This may be referred to as a “tube up” configuration and may position a connection port at the top of the patient’s head. In other example, thepatient may receive the flow of pressurized air through a conduit connected to the plenum chamber 3200, for example through the connection port 3600 (see e.g., Fig. 3A). This may be referred to a “tube down” configuration where the airflow conduit is positioned in front of the patient’s face. Different patients may be more comfortable with one style of air delivery over the other (e.g., because of the patient’s sleep style). Therefore, it may be beneficial to allow a single style of patient interface to be used in either the “tube up” or “tube down” configuration.

[0238] The patient interface may be part of a modular assembly with a variety of interchangeable components that may be swapped out by a patient and / or clinician for one or more components for a different style. The following description describes the various combinations that may be created by assembling the different components together.5.3.10.1 Sleeve

[0239] In some forms, to allow for modularity, a sleeve may be used with the tubes 3350 and / or the rigidisicr arms 3340. The sleeve may at least partially surround the tubes 3350 and / or the rigidiser arms 3340. As shown in Figs. 7G to 71, different shapes of sleeves may be used, which may correspond to different types of positioning and stabilising structures 3300. Tn some forms, the configuration of the sleeve may be customized to fit a particular user’s face. For instance, the sleeves may be configured in a relatively more posterior region of the patient’s head.

[0240] In some forms, the sleeve may be constructed from a comfortable material. For example, the sleeve may be constructed from a textile material, a foam material, or a combination of the two. The comfortable material may contact the patient in use, and may feel soft against the patient’ s skin in order to improve patient compliance.

[0241] The material may also be flexible in order to assist in donning or doffing the sleeve from the tube 3350 or the rigidiser arms 3340. For example, the material may allow the sleeve to bend in order to conform to the shape of the tubes or conduit headgear 3350 or the rigidiser arms 3340, which may change depending on the shape of an individual patient’s head.

[0242] In some forms, the sleeve may also be at least partially clastic (e.g., the material may allow the sleeve to stretch). The elastic material may help the sleeve stretch in order to fit around the tubes 3350 or the rigidiser arms 3340. The elasticmaterial may then return to an initial position that is snug against the tubes 3350 or the rigidiser arms 3340 in order to limit the sleeve from sliding while in use.

[0243] As described in more detail below, some forms of the sleeves may be specific to a rigidising element (e.g., tubes 3350 and / or rigidiser arms 3340).However, the sleeves may assist the rigidising elements in connecting interchangeably with the version or styles of cushions (e.g., the mouth and nose cushion 3050-1, the nose-only cushion 3050-2, etc.).5.3.10.1.1 Conduit Sleeve

[0244] As shown in Fig. 7G, one example of a sleeve is a conduit sleeve 3351, which may be usable with the tubes 3350 described above.

[0245] As shown in Fig. 7G, the conduit sleeve 3351 may include a curved shape that may be similar to the shape of the tubes 3350 shown in Fig. 7C. The flexible material used to construct the conduit sleeve 3351 may allow the conduit sleeve 3351 to further curve in order to correspond to the shape of the tubes 3350 (e.g., when worn by the patient).

[0246] In some forms, the conduit sleeve 3351 may include a first or superior opening 3352. The superior opening 3352 may be disposed at one end of the conduit sleeve 3351 . The superior opening 3352 may be an opening to a passage that extends along at least a portion of the conduit sleeve 3351.

[0247] As shown in Fig. 7G, some forms of the conduit sleeve 3351 may also include an inferior extension 3354. The inferior extension 3354 may be positioned on an opposite end of the conduit sleeve 3351 from the superior opening 3352. The conduit sleeve 3351 may be customized to fit a particular user’s face. For instance, the inferior extension 3354 of the conduit sleeve 3351 may be configured in a relatively more posterior region or anterior region of the patient’s head.

[0248] Some forms of the inferior extension 3354 may include a rigid or semirigid piece (e.g., within the sleeve 3351). The rigid or semi-rigid piece may be constructed from a plastic material, or a similar' material. Alternatively, the inferior extension 3354 may be stiffened using a manufacturing process (e.g., stitching rigidised thread, flat knitting, using thicker material).

[0249] As shown in Fig. 7G, some forms of the inferior extension 3354 may include a connection member 3356. In the illustrated example, the connection member 3356 may be a magnet, although in other examples, the connection member 3356 may be a different type of connector (e.g., a mechanical fastener, an adhesive,hook and loop material, etc.). The connection member 3356 may also be positioned at an end of the inferior extension 3354, although the connection member 3356 could alternatively be positioned anywhere along the inferior extension 3354.

[0250] Tn some forms, the connection member 3356 (e.g., a magnet) may be removably connected to the magnets 3370-1 of the headgear 3302-1. For example, when the conduit sleeves 3351 are connected to the tubes 3350 (see e.g., Fig. 7J), the magnets 3370-1 connected to the inferior straps 3304-1 may be removably connected to the connection member 3356 in order to provide the tensile force.5.3.10.1.2 Four-point arm sleeve

[0251] As shown in Fig. 7H, another example of a sleeve is a four-point arm sleeve 3380, which may be usable with the rigidiser arms 3340 described above.

[0252] As shown in Fig. 7H, the four-point arm sleeve 3380 may include a curved shape that may be similar to the shape of the rigidiser arm 3340 shown in Fig. 7D. The flexible material used to construct the four-point arm sleeve 3380 may allow the four-point arm sleeve 3380 to further curve in order to correspond to the shape of the rigidiser arm 3340 (e.g., when worn by the patient and / or went bent by the patient).

[0253] As shown in Fig. 7H, some forms of the four-point arm sleeve 3380 may include an inferior extension 3384. The inferior extension 3384 may be positioned at an end of the four-point arm sleeve 3380.

[0254] In the illustrated example, the shape and / or structure of the inferior extension 3384 is substantially the same as the shape of the inferior extension 3354.For example, the inferior extension 3384 may be more rigid as compared to the rest of the four-point arm sleeve 3380 (e.g., as a result of rigidising thread or rigid material).

[0255] As shown in Fig. 7H, some forms of the inferior extension 3384 may include a connection member 3386. In the illustrated example, the connection member 3386 may be a magnet, although in other examples, the connection member 3386 may be a different type of connector (e.g., a mechanical fastener, an adhesive, hook and loop material, etc.). The connection member 3386 may also be positioned at an end of the inferior extension 3384, although the connection member 3386 could alternatively be positioned anywhere along the inferior extension 3384.

[0256] Tn some forms, the connection member 3386 (e.g., a magnet) may be removably connected to the magnets 3370-1 of the headgear 3302-1. For example, when the four-point arm sleeves 3380 are connected to the rigidiser arm 3340 (seee.g., Fig. 7K), the magnets 3370-1 connected to the inferior straps 3304-1 may be removably connected to the connection member 3386 in order to provide the tensile force.

[0257] As shown in Fig. 7H, the four-point arm sleeve 3380 may include a pair of tabs 3394, which may be similar to the tab 3320 on the tubes 3350. When the four- point arm sleeve 3380 is worn by the patient, the tabs 3394 may be positioned in substantially the same place on the patient’s head as where the tabs 3320 are positioned when the patient wears the tubes 3350.5.3.10.1.3 Two-point arm sleeve

[0258] As shown in Fig. 71, yet another example of a sleeve is a two-point arm sleeve 3380-1 , which may be usable with the rigidiser arms 3340 described above.

[0259] In some forms, the two-point arm sleeve 3380-1 may be similar to the four-point arm sleeve 3380 described above. Only some similarities and differences may be described below.

[0260] As shown in Fig. 71, the two-point arm sleeve 3380-1 may include an inferior opening 3388-1 that is positioned at an end of the two-point arm sleeve 3380- 1. The inferior opening 3388-1 may form an opening to a passageway through the two-point arm sleeve 3380-1 . In the illustrated example, the inferior opening 3388-1 may open into a surface of the conduit sleeve 3380-1.

[0261] As shown in Fig. 71, the two-point arm sleeve 3380-1 may include a pair of tabs 3394-1, which may be similar' to the tab 3320 on the tubes 3350. When the two-point arm sleeve 3380-1 is worn by the patient, the tabs 3394-1 may be positioned in substantially the same place on the patient’s head as where the tabs 3320 are positioned when the patient wears the tubes 3350.5.3.10.2 Assembled Patient Interfaces

[0262] As illustrated in Figs. 7J to 7M, the various elements described above may be combined into four different patient interfaces. The different patient interfaces may allow patients to use different styles based on their individual comfort. The modularity of the different elements (e.g., the ability to be used in multiple styles of patient interfaces) may simplify manufacturing and / or may allow a patient to more easily switch between styles of patient interfaces.5.3.10.2.1 Nose and Mouth Mask Tube Up Configuration

[0263] As illustrated in Fig. 7.T, the patient may wear the cushion 3050-1 in a tube-up configuration with the tubes 3350 and the four-point headgear 3302-1. This assembly may form a tube up nose and mouth patient interface 3000-1 .

[0264] In some forms, a conduit sleeve may be used with the tubes 3350 in order to enable a patient to experience the “tube up” air delivery style with the mouth and nose cushion 3050-1. As is described below, the conduit sleeve provides additional connection locations for connecting the four-point headgear 3302-1. However, other forms of connectors aside from or in addition to the conduit sleeve may be used.

[0265] In the illustrated example, the conduit sleeves may be connected to the tubes 3350 of the positioning and stabilising structure 3300. The tubes 3350 (via the conduit connection structure 3500), may be used to connect the tubes 3350 to the cushion 3050-1. The conduit sleeves provide the magnets in order to connect to the magnets 3370-1 (see e.g., Fig. 7E) of the four-point headgear 3302-1. Alternatively, a different connection form may be used.

[0266] As illustrated in Fig. 7 J, the four-point headgear 3302-1 may connect in four separate locations in order to provide a tensile force that maintains the cushion 3050-1 in a sealing position on the patient’s head.

[0267] For example, the inferior straps 3304-1 (e.g., via the magnetic members 3306-1) may removably connect to the magnets of the conduit sleeves. In use, each inferior strap 3304-1 may contact the patient’s cheek (e.g., overlaying the masseter muscle). The inferior straps 3304-1 may also extend below the patient’s cars.5.3.10.2.2 Nose and Mouth Mask Tube Down Configuration

[0268] As illustrated in Fig. 7K, the patient may wear the cushion 3050-1 in a tube-down configuration with the rigidiser arms 3340 and the four-point headgear 3302-1. This assembly may form a tube down nose and mouth patient interface 3000- 2.

[0269] In some forms, a conduit sleeve may be used with the rigidiser arms 3340 in order to enable a patient to experience the “tube down” air delivery style with the mouth and nose cushion 3050-1. As is described below, the conduit sleeve provides additional connection locations for connecting the four-point headgear 3302-1.However, other forms of connectors aside from or in addition to the conduit sleeve may be used.

[0270] In the illustrated example, the conduit sleeves may be connected to the rigidiser arms 3340 of the positioning and stabilising structure 3300. The rigidiser arms 3340 (via the conduit connection structure 3504), may be used to connect the rigidiser arms 3340 to the cushion 3050-1. The conduit sleeves provide the magnets in order to connect to the magnets 3370-1 (see e.g., Fig. 7E) of the four-point headgear 3302-1. Alternatively, a different connection form may be used.

[0271] As illustrated in Fig. 7K, the four-point headgear 3302-1 may connect in four separate locations in order to provide a tensile force that maintains the cushion 3050-1 in a sealing position on the patient’s head.

[0272] For example, the inferior straps 3304-1 (e.g., via the magnetic members 3306-1) may removably connect to the magnets of the conduit sleeves. Tn use, each inferior strap 3304-1 may contact the patient’s cheek (e.g., overlaying the masseter muscle). The inferior straps 3304-1 may also extend below the patient’s ears.5.3.10.2.3 Nose Mask Tube Up Configuration

[0273] As illustrated in Fig. 7L, the patient may wear the cushion 3050-2 in a tube-up configuration with the tubes 3350 and the two-point headgear 3302-2. This assembly may form a tube up nose only patient interface 3000-3

[0274] A conduit sleeve may be used with the tubes 3350, and may provide additional comfort to the patient. The sleeve may not add additional connection points to connect the positioning and stabilising structure 3300 on the cushion 3050-2. In the illustrated example, the tubes 3350 of the positioning and stabilising structure 3300 may be connected directly to the cushion 3050-2.

[0275] As illustrated in Fig. 7L, the two-point headgear 3302-2 may connect to the tabs 3320 on the tubes 3350 in order to provide a tensile force that maintains the cushion 3050-2 in a sealing position on the patient’s head.5.3.10.2.4 Nose Mask Tube Down Configuration

[0276] As illustrated in Fig. 7M, the patient may wear the cushion 3050-2 in a tube-up configuration with the rigidiser arms 3340 and the two-point headgear 3302- 2. This assembly may form a tube down nose only patient interface 3000-4.

[0277] A conduit sleeve may be used with the rigidiser arms 3340, and may provide additional comfort to the patient. The sleeve may not add additional connection points to connect the positioning and stabilising structure 3300 on the cushion 3050-2. In the illustrated example, the rigidiser arms 3340 of the positioning and stabilising structure 3300 may be connected directly to the cushion 3050-2.

[0278] As illustrated in Fig. 7M, the two-point headgear 3302-2 may connect to the tabs 3320 on the sleeve in order to provide a tensile force that maintains the cushion 3050-2 in a sealing position on the patient’s head.5.3.10.2.5 Modularity of Elements

[0279] Fig. 7P illustrates how the different elements can be combined in order to form the four different patient interfaces described above. As illustrated, the different components may be reused for different styles of patient interfaces. This may allow for easier manufacturing and assembly, because a large number of the same components may be produced and used in a variety of styles. The only components not used in multiple styles may be the sleeves. However, the sleeves may be easier to manufacture. Fig. 70 shows a portion of air circuit 4170 that may interface with the patient interface, while Fig. 7N shows a vent 3404 that may interchangeably replace the air circuit shown in Fig. 70, depending on the style of the patient interface.5.4 RPT DEVICE

[0280] 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 of the respiratory' conditions described elsewhere in the present document.

[0281] In one form, the RPT device 4000 is constructed and arranged to be capable of delivering a flow of air in a range of -20 L / min to +150 L / min while maintaining a positive pressure of at least 4 cmH20, or at least 10cmH2O, or at least 20 cmH20.

[0282] The RPT device may have an external housing 4010, formed in two parts, an upper portion 4012 and a lower portion 4014. Furthermore, the external housing 4010 may include one or more panel(s) 4015. The RPT device 4000 comprises a chassis 4016 that supports one or more internal components of the RPT device 4000. The RPT device 4000 may include a handle 4018.

[0283] The pneumatic path of the RPT device 4000 may comprise one or more air path items, c.g., an inlet air filter 4112, an inlet muffler 4122, a pressure generator 4140 capable of supplying air at positive pressure (e.g., a blower 4142), an outlet muffler 4124 and one or more transducers 4270, such as pressure sensors 4272 and flow rate sensors 4274.

[0284] One or more of the air path items may be located within a removable unitary structure which will be referred to as a pneumatic block 4020. The pneumatic block 4020 may be located within the external housing 4010. In one form a pneumatic block 4020 is supported by, or formed as part of the chassis 4016.5.5 AIR CIRCUIT

[0285] An air circuit 4170 in accordance with an aspect of the present technology is a conduit or a tube constructed and arranged to allow, in use, a flow of air to travel between two components such as RPT device 4000 and the patient interface 3000 or 3800.5.6 HUMIDIFIER5.6.1 Humidifier overview

[0286] In one form of the present technology there is provided a humidifier 5000 (c.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 the absolute humidity and increase the temperature of the flow of air (relative to ambient air) before delivery to the patient’s airways.

[0287] 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 5240.5.7 GUOSSARY

[0288] 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.5.7.1 General

[0289] 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.

[0290] 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.

[0291] Continuous Positive Airway Pressure (CPAP) therapy: Respiratory pressure therapy in which the treatment pressure is approximately constant through a respirator}' 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.

[0292] Patient: A person, whether or not they are suffering from a respiratory condition.

[0293] Pressure: Force per unit area. Pressure may be expressed in a range of units, including cmFFO, g-f / cm2and hcctopascal. 1 cmkhO 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 cmFFO.

[0294] 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.

[0295] 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.5,7.1.1 Materials & their properties

[0296] 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.

[0297] 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 Coming. 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.

[0298] Polycarbonate', a thermoplastic polymer of Bisphenol- A Carbonate.5.7.1.2 Mechanics

[0299] Axes: a. Neutral axis'. An axis in the cross-section of a beam or plate along which there are no longitudinal stresses or strains. b. Longitudinal axis: An axis extending along the length of a shape. The axis generally passes through a center of the shape. c. 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.

[0300] 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.

[0301] Elasticity: The ability of a material to return to its original geometry after deformation.

[0302] 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.

[0303] Resilience: Ability of a material to absorb energy when deformed elastically and to release the energy upon unloading.

[0304] Resilient: Will release substantially all of the energy when unloaded. Includes e.g. certain silicones, and thermoplastic elastomers.

[0305] 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 sealingrelationship with an entrance to a patient's airways, e.g. at a load of approximately 20 to 30 cmH20 pressure.

[0306] 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.

[0307] 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. The structure or component may offer different resistances in different directions. The inverse of stiffness is flexibility.

[0308] Yield: The situation when a material can no longer return back to its original geometry after deformation.5.7.1.3 Structural Elements

[0309] Compression member: A structural clement that resists compression forces.

[0310] 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.

[0311] Frame: Frame w'ill be taken to mean a mask structure that bears the load of tension between t 'o 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.

[0312] 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.

[0313] Tie (noun): A structure designed to resist tension.[0314 J Thin structure s :a. 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 b. Membranes, i. Relatively long in two dimensions, with one thin dimension. Readily deforms in response to bending forces. Resists being stretched, (might also resist compression). c. Plates & Shells i. These may be relatively long in two directions, with one thin dimension. They may have bending, tensile, and / or compressive stiffness.LO315J Thick structures: Solids

[0316] 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.

[0317] 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.

[0318] 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.

[0319] 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.

[0320] 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.5.7.2 Respiratory cycle

[0321] 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 to have 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.5.7.3 Anatomy5.7.3.1 Anatomy of the face

[0322] Ala: the external outer wall or "wing" of each nostril (plural: alar)

[0323] Columella: the strip of skin that separates the nares and which runs from the pronasale to the upper lip.

[0324] Frankfort horizontal plane: A line extending from the most inferior point of the orbital margin to the left tragion. The tragion is the deepest point in the notch superior to the tragus of the auricle.

[0325] Lip, lower (labrale inferius): The lip extending between the subnasale and the mouth.

[0326] Lip, upper (labrale superius): The lip extending between the mouth and the supramenton.

[0327] 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.

[0328] Naso-labial sulcus or Naso-labial fold: The skin fold or groove that runs from each side of the nose to the corners of the mouth, separating the cheeks from the upper lip.

[0329] Otobasion inferior: The lowest point of attachment of the auricle to the skin of the face.

[0330] Otobasion superior: The highest point of attachment of the auricle to the skin of the face.

[0331] 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.

[0332] Ridge (nasal): The nasal ridge is the midline prominence of the nose, extending from the Sellion to the Pronasale.

[0333] 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.

[0334] Sellion: Located on the soft tissue, the most concave point overlying the area of the frontonasal suture.5,7.3.2 Anatomy of the skull

[0335] Frontal bone: The frontal bone includes a large vertical portion, the squama frontalis, corresponding to the region known as the forehead.

[0336] 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.

[0337] Parietal bones: The parietal bones are the bones that, when joined together, form the roof and sides of the cranium.

[0338] 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.5.7.4 Patient interface

[0339] 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.

[0340] 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.

[0341] 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.

[0342] 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.

[0343] 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.5.8 OTHER REMARKS

[0344] 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.

[0345] 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 lo 'er 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.

[0346] Furthermore, w'here 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.

[0347] Furthermore, “approximately”, “substantially”, “about”, or any similar term used herein means + / - 5-10% of the recited value.

[0348] 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.

[0349] 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.

[0350] 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.

[0351] 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.

[0352] 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.

[0353] The subject headings used in the detailed description are included only for the case 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.

[0354] 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 bemodified and / or aspects thereof may be conducted concurrently or even synchronously.

[0355] 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.

Claims

CLAIMS1. A strap for a positioning and stabilising structure for a patient interface, the positioning and stabilising structure configured to provide a force to hold a seal-forming structure of the patient interface in a therapeutically effective position on the patient’s head during use of the patient interface for treatment of sleep disordered breathing, the strap comprising: a body having a length, a width transverse to the length, and a pair of end portions at opposite ends of the length, the end portions being constructed and arranged to connect to a portion of the patient interface in use; wherein the body of the strap comprises a user-facing surface configured to engage the user’ s hair and / or skin in use, the user-facing surface having a first surface portion and a second surface portion, the first surface portion providing a first coefficient of friction between the strap and the user’s hair or skin, the second surface portion providing a second coefficient of friction between the strap and the user's hair or skin, the second coefficient of friction being greater than the first coefficient of friction.

2. The strap of claim 1, wherein the second coefficient of friction is within the range of 0.1-1.1.

3. The strap of claim 2, wherein the second coefficient of friction is within the range of 0.6- 1.1.

4. The strap of claim 1, wherein the second coefficient of friction is within the range of 0.1-0.7.

5. The strap of any one of claims 1-4, wherein the body of the strap is bifurcated.

6. The strap of any one of claims 1 -5, wherein the body of the strap is formed at least partially from a first material, the first material being a textile material, the first surface portion being formed at least partially by the first material.

7. The strap of claim 6, wherein the interior of the body of the strap is formed from foam.

8. The strap of claim 6 or claim 7, wherein the second surface portion is transparent.

9. The strap of any one of claims 6-8, wherein the second surface portion extends along the length of the body of the strap.

10. The strap of claim 9, wherein the second surface portion is positioned centrally with respect to the width of the body of the strap and the user-facing surface comprises a pair of first surface portions extending parallel to the second surface portion on opposite adjacent sides of the second surface portion across the width of the strap.

11. The strap of claim 9, wherein the user-facing surface is formed by a plurality of second surface portions extending along the length of the body of the strap, the second surface portions being separated across the width of the body of the strap by a plurality of first surface portions.

12. The strap of claim 11, wherein the plurality of second surface portions comprises one second surface portion provided centrally with respect to the width of the body of the strap and a pair of second surface portions provided at opposite edges of the width of the strap.

13. The strap of claim 12, wherein the pair of second surface portions provided at opposite edges of the width of the strap arc narrower than the second surface portion provided centrally.

14. The strap of any one of claims 6-13, wherein the second surface portion is formed at least partially by a second material different to the first material.

15. The strap of claim 14, wherein the second material is an elastomeric material.

16. The strap of clam 15, wherein the second material is silicone.

17. The strap of any one of claims 14-16, wherein the second material is woven into the first material.

18. The strap of claim 17, wherein the second material comprises a TPU yarn.

19. The strap of any one of claims 14-16, wherein the second material is coated over the first material to form a coated area.

20. The strap of any one of claims 14-16, wherein the second material is coated over the first material and the user-facing surface comprises a plurality of second surface portions each in the form of a coated area.

21. The strap of claim 19 or 20, wherein the coated area is circular.

22. The strap of claim 19 or 20, wherein the user-facing surface comprises a group of coated areas forming a circle.

23. The strap of any one of claims 19-22, wherein the user-facing surface comprises a plurality of groups of coated areas.

24. The strap of claim 23, wherein each group of coated areas is spaced from an adjacent group of coated areas by a first surface portion.

25. The strap of claim 23, wherein each group of coated areas expands across substantially the full width of the body of the strap and is spaced from an adjacent group of coated areas along the length of the body of the strap by a first surface portion.

26. The strap of claim 23, wherein each group of coated areas has a dimension aligned with the width of the body of the strap, said dimension being greater than or equal to half the width of the body of the strap.

27. The strap of claim 23, wherein each group of coated areas has a dimension aligned with the width of the body of the strap, said dimension being less than half the width of the body of the strap.

28. The strap of any one of claims 19-21, wherein the user-facing surface comprises a group of coated areas extending along the length of the body of the strap.

29. The strap of claim 28, wherein the group is located centrally with respect to the width of the body of the strap and spaced from opposite edges of the body of the strap by first surface portions.

30. The strap of claim 19 or 20, wherein the user-facing surface comprises a group of coated areas in the form of a bullseye pattern.

31. The strap of claim 30, wherein the user-facing surface comprises a plurality of groups of coated areas each in the form of a bullseye pattern.

32. The strap of claim 30 or 31, wherein the bullseye pattern has a diameter greater than or equal to half of the width of the body of the strap.

33. The strap of claim 30 or 31, wherein the bullseye pattern has a diameter less than half the width of the body of the strap.

34. The strap of claim 33, wherein the bullseye pattern has a diameter less than or equal to a third of the width of the body of the strap.

35. The strap of any one of claims 19-21, wherein the user-facing surface comprises a group of coated areas forming a rectangle.

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