Headgear for patient interface including flow generator

Abstract

A positioning and stabilising structure for a patient interface, the positioning and stabilising structure comprising: a pair of lateral portions, each lateral portion comprises a respective one of a pair of arm connection portions each configured to be connected to a respective one of a pair of arms extending posteriorly from the patient interface, each lateral portion comprises a rigidised portion; a frontal strap portion, a parietal strap portion and an occipital strap portion each formed at least partially by the lateral portions, wherein each rigidised portion comprises a first portion located within the frontal strap portion, a second portion located within the parietal strap portion and a third portion located within the occipital strap portion.

Description

HEADGEAR FOR PATIENT INTERFACE INCLUDING FLOW GENERATOR

[0001] 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.1 CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Australian Patent Application No. 2024904093, filed 10 December 2024, the entire contents of which is hereby incorporated by reference.2 BACKGROUND OF THE TECHNOLOGY2.1 FIELD OF THE TECHNOLOGY

[0003] 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.

[0004] Also, the present technology relates generally to head mounted displays, positioning and stabilising structures, user interfacing structures, and other components for use in head mounted displays, associated head-mounted display assemblies and systems including a display unit and positioning and stabilising structure, interfacing structures and or components, and methods. The present technology finds particular application in the use of virtual reality head mounted displays and is herein described in that context. However, it is to be appreciated that the present technology may have broader application and may be used in other headmounted display arrangements including augmented reality displays.2.2 DESCRIPTION OF THE RELATED ART2.2.1 Human Respiratory System and its Disorders

[0005] The respiratory system of the body facilitates gas exchange. The nose and mouth form the entrance to the airways of a patient.

[0006] 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 theA2578192 11.8 1venous blood and carbon dioxide to move in the opposite direction. The trachea divides into right and left main bronchi, which further divide eventually into terminal bronchioles. The bronchi make up the conducting airways, and do not take part in gas exchange. Further divisions of the airways lead to the respiratory bronchioles, and eventually to the alveoli. The alveolated region of the lung is where the gas exchange takes place, and is referred to as the respiratory zone. See “ Respiratory Physiology”, by John B. West, Lippincott Williams & Wilkins, 9th edition published 2012.

[0007] A range of respiratory disorders exist. Certain disorders may be characterised by particular events, e.g., apneas, hypopneas, and hyperpneas.

[0008] 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.

[0009] A range of therapies have been used to treat or ameliorate such conditions. Furthermore, otherwise healthy individuals may take advantage of such therapies to prevent respiratory disorders from arising. However, these have a number of shortcomings.2.2.2 Therapies

[0010] 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

[0011] 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).

[0012] 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 toA2578192 11.8 2provide such therapy one or more of: uncomfortable, difficult to use, expensive and aesthetically unappealing.2.2.3 Respiratory Therapy Systems

[0013] 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.

[0014] 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

[0015] 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 cmFFO 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 crnFFO. 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.

[0016] Certain other mask systems may be functionally unsuitable for the present field. For example, purely ornamental masks may be unable to maintain a suitable pressure. Mask systems used for underwater swimming or diving may be configured to guard against ingress of water from an external higher pressure, but not to maintain air internally at a higher pressure than ambient.

[0017] Certain masks may be clinically unfavourable for the present technology e.g., if they block airflow via the nose and only allow it via the mouth.

[0018] Certain masks may be uncomfortable or impractical for the present technology if they require a patient to insert a portion of a mask structure in their mouth to create and maintain a seal via their lips.A2578192 11.8 3

[0019] 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.

[0020] 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.

[0021] As a consequence of these challenges, some masks suffer from being one or more of obtrusive, aesthetically undesirable, costly, poorly fitting, difficult to use, and uncomfortable especially when worn for long periods of time or when a patient is unfamiliar with a system. Wrongly sized masks can give rise to reduced compliance, reduced comfort and poorer patient outcomes. Masks designed solely for aviators, masks designed as part of personal protection equipment (e.g., filter masks), SCUBA masks, or for the administration of anaesthetics may be tolerable for their original application, but nevertheless such masks may be undesirably uncomfortable to be worn for extended periods of time, e.g., several hours. This discomfort may lead to a reduction in patient compliance with therapy. This is even more so if the mask is to be worn during sleep.

[0022] CPAP therapy is highly effective to treat certain respiratory disorders, provided patients comply with therapy. If a mask is uncomfortable, or difficult to use a patient may not comply with therapy. Since it is often recommended that a patient regularly wash their mask, if a mask is difficult to clean (e.g., difficult to assemble or disassemble), patients may not clean their mask, and this may impact on patient compliance.

[0023] 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.

[0024] For these reasons, patient interfaces for delivery of CPAP during sleep form a distinct field.2.2.3.1.1 Seal-forming structure

[0025] 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 -formingA2578192 11.8 4structure can have a direct impact the effectiveness and comfort of the patient interface.

[0026] A range of patient interface seal-forming structure technologies are disclosed in the following patent applications, assigned to ResMed Limited: WO 1998 / 004310; WO 2006 / 074513; WO 2010 / 135785.2.2.3.1.2 Positioning and stabilising

[0027] 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.

[0028] One technique is the use of adhesives. See for example US Patent Application Publication No. US 2010 / 0000534. However, the use of adhesives may be uncomfortable for some.

[0029] 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 Respiratory Pressure Therapy (RPT) Device

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

[0032] The designer of a device may be presented with an infinite number of choices to make. Design criteria often conflict, meaning that certain design choicesA2578192 11.8 5are 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

[0033] 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.2.1.3.4 Data Management

[0034] There may be clinical reasons to obtain data to determine whether the patient prescribed with respiratory therapy has been “compliant”, e.g. that the patient has used their RPT device according to one or more “compliance rules”.

[0035] There may be other aspects of a patient’s therapy that would benefit from communication of therapy data to a third party or external system.

[0036] Existing processes to communicate and manage such data can be one or more of costly, time-consuming, and error-prone.2.2.4 Immersive Technology

[0037] An immersive technology refers to technology that attempts to replicate or augment a physical environment through the means of a digital or virtual environment by creating a surrounding sensory feeling, thereby creating a sense of immersion.

[0038] In particular, an immersive technology provides the user visual immersion, and creates virtual objects and / or a virtual environment. The immersive technology may also provide immersion for at least one of the other five senses.2.2.5 Virtual Reality

[0039] Virtual reality (VR) is a computer-generated three-dimensional image or environment that is presented to a user. In other words, the environment may be entirely virtual. Specifically, the user observes an electronic screen in order to observe virtual or computer generated images in a virtual environment. Since the created environment is entirely virtual, the user may be blocked and / or obstructed from interacting with their physical environment (e.g., they may be unable to hearA2578192 11.8 6and / or see the physical objects in the physical environment that they are currently located).2.2.6 Augmented Reality

[0040] In some forms, augmented reality (AR) is a computer-generated three- dimensional image or environment that is presented to a user.

[0041] While similar to VR, AR differs in that the virtual environment created at least in part by the electronic screen is observed in combination with the user’s physical environment. In other words, AR creates virtual objects in order to alter and / or enhance the user’s physical environment with elements of a virtual environment. The result of AR is a combined environment that includes physical and virtual objects, and therefore an environment that is both physical and virtual.2.2.7 Mixed Reality

[0042] Mixed reality (MR) is similar to AR but may be more immersive because the MR device may provide the user more ways to interact with virtual objects or environment than an AR device. The virtual reality in MR may also be overlayed and / or blended with the user’s physical environment. Unlike AR however, a user may be able to interact with the virtual environment akin to what occurs in VR. In other words, while AR may present only an computer generated image in the physical environment, MR may present the user with the same or similar computer generated image but allow for interaction with the image in the physical environment (e.g., using a hand to “grab” an object produced virtually). Thus, the virtual environment may further merge with a physical environment so that the combined environment better replicates an actual environment.2.2.8 Head-Mounted Display Interface

[0043] A head-mounted display interface enables a user to have an immersive experience of a virtual environment and have broad application in fields such as communications, training, medical and surgical practice, engineering, and video gaming.

[0044] Different head-mounted display interfaces can each provide a different level of immersion. For example, some head-mounted display interfaces can provideA2578192 11.8 7the user with a total immersive experience. One example of a total immersive experience is virtual reality (VR). The head-mounted display interface can also provide partial immersion consistent with using an AR device.

[0045] In any types of immersive technology, it is advantageous that the headmounted display interface is comfortable and / or stable in order to allow the user to wear the head-mounted display for extended periods of time.2.2.8.1 Interfacing structure

[0046] The head-mounted displays may include a user interfacing structure. Since it is in direct contact with the user’s face, the shape and configuration of the interfacing portion can have a direct impact on the effectiveness and comfort of the display unit.

[0047] The design of a user interfacing structure 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.2.2.8.2 Positioning and stabilizing

[0048] To hold the display unit in its correct operational position, the headmounted display system further comprises a positioning and stabilizing structure that is disposed on the user’s head. These structures may be responsible for providing forces to counter gravitational forces of the head-mounted display and / or interfacing structure. In the past these structures have been formed from expandable rigid structures that are typically applied to the head under tension to maintain the display unit in its operational position. Such systems have been prone to exert a clamping pressure on the user’s face which can result in user discomfort at localised stress points. Also, previous systems may be difficult to adjust to allow wide application head sizes. Further, the display unit and associated stabilizing structure are often heavy, difficult to clean which further limit the comfort and useability of the system.

[0049] Certain other head mounted display systems may be functionally unsuitable for the present field. For example, positioning and stabilizing structures designed for ornamental and visual aesthetics may not have the structural capabilitiesA2578192 11.8 8to maintain a suitable pressure around the face. For example, an excess of clamping pressure may cause discomfort to the user, or alternatively, insufficient clamping pressure on the users’ face may not effectively seal the display from ambient light.

[0050] Certain other head mounted display systems may be uncomfortable or impractical for the present technology. For example, if the system is used for prolonged time periods.

[0051] As a consequence of these challenges, some head mounted displays suffer from being one or more of obtrusive, aesthetically undesirable, costly, poorly fitting, difficult to use, and uncomfortable especially when worn for long periods of time or when a user is unfamiliar with a system. Wrongly sized positioning and stabilizing structures can give rise reduced comfort and in turn, shortened periods of use.

[0052] Therefore, an interfacing portion of a user interface used for the fully immersive experience of a virtual environment are subject to forces corresponding to the movement of a user during the experience.2.1.8.3 Materials

[0053] Materials used in head mounted display assemblies have included dense foams for contacting portions in the interfacing structures, rigid shells for the housings, and positioning and stabilizing structures formed from rigid plastic clamping structures. These materials have various drawbacks including not permitting the skin covered by the material to breath, being inflexible, difficult to clean and to prone trapping bacteria. As a result, products made with such material may be uncomfortable to wear for extended periods of time, causes skin irritation in some individuals and limit the application of the products.3 BRIEF SUMMARY OF THE TECHNOLOGY

[0054] The present technology is directed towards providing medical devices used in the screening, diagnosis, monitoring, amelioration, treatment, or prevention of respiratory disorders having one or more of improved comfort, cost, efficacy, ease of use and manufacturability.

[0055] A first aspect of the present technology relates to apparatus used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respiratory disorder.A2578192 11.8 9

[0056] Another aspect of the present technology relates to methods used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respiratory disorder.

[0057] 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.

[0058] One form of the present technology comprises the patient interface includes a flow generator for providing a flow of pressurized air to the patient.

[0059] Another aspect of one form of the present technology is the flow generator casing connected to a cushion of a patient interface, the flow generator casing housing a blower for providing pressurized air to the cushion.

[0060] Another aspect of one form of the present technology is the power source removably connected to the patient interface for providing electrical energy to the patient interface.

[0061] In one form, the power source is a rechargeable battery connected directly to the patient interface.

[0062] Another aspect of one form of the present technology is a patient interface includes a cushion and a blower in a blower housing connected directly to the cushion. The patient interface also includes a power source providing electrical energy to the blower.

[0063] In one form, the blower and / or the power source are worn and supported by the user in use.

[0064] Another aspect of one form of the present technology is a patient interface including a plenum chamber pressurizable to a therapeutic pressure; a seal-forming structure configured to form a seal against the patient’s face; a positioning and stabilising structure configured to provide a force for maintaining the seal-forming structure in a therapeutically effective position; an RPT device connected directly to the plenum chamber, the PRT device including a blower for providing airflow at the therapeutic pressure, wherein the positioning and stabilising structure configured to support at least part of the weight of the RPT device; and an electrical power source electrically connected to the RPT device.

[0065] In some forms, a) the positioning and stabilising structure may support at least a portion of the weight of the electrical power source; b) the electrical power source is a rechargeable battery; and / or c) the patient interface is removably connected to a charger for recharging the battery.A2578192 11.8 10

[0066] In some forms, a) the RPT device includes a flow generator casing with a cavity housing a blower; b) the cavity is in fluid communication with the plenum chamber; and / or c) the flow generator casing extends around at least a portion of the plenum chamber.

[0067] In some forms, a) the RPT device includes a valve positioned between the blower and the plenum chamber; and / or b) the valve is a one-way valve.

[0068] Another aspect of one form of the present technology is a patient interface that is moulded or otherwise constructed with a perimeter shape which is complementary to that of an intended wearer.

[0069] Another aspect of one form of the present technology is a head-mounted display interface comprising: a user interface structure configured to contact the user’s face, the user interface structure including at least one first opening configured to receive at least one of the user’s eyes, and at least one second opening configured to receive at least one of the user’s nares; a display unit housing connected to the user interface structure, the display unit housing including a display configured to output a computer generated image through the at least one first opening, and a blower configured to output a flow of pressurized air through the at least one second opening; and a support structure connected to the display unit housing and / or the user interface structure and configured to maintain the user interface structure in a desired position on the user’s face.

[0070] In some forms, the blower is constructed and arranged to be able to provide a supply of air at a positive pressure of at least 4 cmH20 with respect to ambient.

[0071] In some forms, the head-mounted display interface further includes an audio system configured to output sound to a user.

[0072] Another aspect of the present technology is directed to a patient interface for treating a patient with a respiratory disorder, comprising a respiratory pressure therapy (RPT) device including an electric blower configured to generate pressurized breathable air; a seal -forming structure configured to form a seal against the patient’s face, the seal-forming structure at least partially defining a plenum chamber configured to receive the pressurized air; a flow generator casing that at least partly encloses the electric blower and is connected to the plenum chamber, the casing including at least one air opening to receive ambient air for delivery to the RPTA2578192 11.8 11device; and a positioning and stabilising structure configured to maintain the sealforming structure and the blower in a therapeutically effective position.

[0073] Another aspect of the present technology is directed to a patient interface for treating a patient with a respiratory disorder, comprising: a respiratory pressure therapy (RPT) device including an electric blower configured to generate pressurized breathable air; a seal -forming structure configured to form a seal against the patient’s face and deliver a flow of breathable air to an entrance to the patient’s airways, the seal-forming structure at least partially defining a plenum chamber configured to receive the pressurized air; a flow generator casing that at least partly encloses the electric blower and is connected to the plenum chamber, the casing including at least one air opening to receive ambient air for delivery to the RPT device; and a positioning and stabilising structure configured to maintain the sealforming structure and the blower in a therapeutically effective position, the positioning and stabilising structure comprising: a pair of arms attached in use to the flow generator casing on respective sides thereof, the arms extending posteriorly from the flow generator casing; a parietal strap portion configured to engage the user’s head at a region overlying the parietal bones of the user’s head in use, the parietal strap portion being connected to each of the pair of arms; wherein the parietal strap portion is semi-rigid to resist bending in superior and inferior directions in use; wherein the parietal strap portion comprises a predetermined shape whereby, on each lateral side of the user’s head, the parietal strap portion curves superiorly away from each of the arms.

[0074] A positioning and stabilising structure for a patient interface, the patient interface comprising a flow generator casing, the positioning and stabilising structure constructed and arranged to hold the flow generator casing in an operable position on the user’s head in use, the positioning and stabilising structure comprising: a parietal strap portion configured to engage the user’s head at a region overlying the parietal bones of the user’s head in use, the parietal strap portion beingA2578192 11.8 12connected to each one of a pair of arms extending posteriorly from the flow generator casing on respective sides thereof; wherein the parietal strap portion is semi-rigid to resist bending in superior and inferior directions in use; wherein the parietal strap portion comprises a predetermined shape whereby, on each lateral side of the user’s head, the parietal strap portion curves superiorly away from each of the arms.

[0075] In examples:• the parietal strap portion comprises a pair of anterior portions each connected to a respective one of the pair of arms, and a posterior portion connected to the anterior portions and configured to engage the region overlying the parietal bones of the user’s head;• the posterior portion of the parietal strap portion is formed at least partially from foam;• the posterior portion of the parietal strap portion comprises a textile covering;• the posterior portion of the parietal strap portion is constructed to have a predetermined curved shape;• the posterior portion of the parietal strap portion is dome shaped;• the posterior portion of the parietal strap portion is wider in a medial portion thereof than at lateral ends thereof;• the parietal strap portion is adjustable in length;• one or both of the anterior portions are moveable with respect to the posterior portion to adjust the length of the parietal strap portion;• one or both of the anterior portions are able to slide in the length direction of the posterior portion to extend from or retract into the posterior portion;• the parietal strap portion comprises one or more counterweights;• the parietal strap portion comprises a pair of counterweights, each spaced from and located on opposing sides of the mid-sagittal plane of the user’s head in use;A2578192 11.8 13• the positioning and stabilising structure comprises a frontal strap portion constructed and arranged to engage the user’ s head in use in a region overlying the frontal bone of the user’s head;• the positioning and stabilising structure comprising a band strap portion constructed and arranged to encircle the user’s head in use, the band strap portion overlying the user’s forehead and forming an occipital strap portion constructed and arranged to engage a region of the user’s head overlying or lying inferior to the occipital bone in use;• the band strap portion is elastically extendable in length;• the band strap portion has an unextended length which is selectively adjustable;• the band strap portion comprises an occipital pad positioned in use to engage the region of the user’s head overlying or lying inferior to the occipital bone;• the occipital pad is formed from an elastomeric material;• the occipital pad is formed from foam;• the occipital pad comprises a textile outer layer;• lateral portions of the band strap portion are held apart from each other by the parietal strap portion prior to donning of the patient interface by the user;• the band strap portion passes between two layers of the parietal strap portion on each lateral side of the user’s head in use;• the frontal strap portion comprises a forehead pad configured to engage the user’s forehead;• the forehead pad is formed at least partially from an elastomeric material;• the forehead pad is formed at least partially from a foam material;• the forehead pad is formed at least partially from a textile material;• the forehead pad comprises an elastomeric user-contacting surface;• the forehead pad is provided to the band strap portion;• the forehead pad is attached to the flow generator casing and the band strap portion overlies the forehead pad or engages the user’s forehead superior to the forehead pad;• the forehead pad comprises a frame and a cushion attached to the frame;• the frame of the forehead pad is attached to the flow generator casing;A2578192 11.8 14• the head-mounted display system comprises an interfacing structure connected to the flow generator casing and constructed and arranged to engage the user’s face in use around a periphery of the user’s eye region;• the interfacing structure is constructed and arranged to engage sphenoid regions, cheek regions and the forehead region of the user’s face;• the patient interface comprises a frontal connector constructed and arranged to connect between the frontal strap portion of the positioning and stabilising structure and each of the arms to support at least some weight of the flow generator casing in use via the arms;• the frontal connector comprises a pair of lateral portions each extending towards and attaching to a respective one of the arms;• the frontal connector is attached to a forwardmost portion of the each of the arms;• the positioning and stabilising structure comprises a top strap portion constructed and arranged to engage superior surfaces of the user’s head and connecting between the parietal strap portion and the frontal strap portion of the positioning and stabilising structure and / or the flow generator casing;• the top strap portion is constructed and arranged to connect between the parietal strap portion and the band strap portion;• the top strap portion is substantially aligned with the user’s mid-sagittal plane;• the parietal strap portion is connected to the occipital strap portion;• the positioning and stabilising structure comprises a posterior support portion engaging the user’s head in the region overlying the parietal bones and in the region overlying or lying inferior to the occipital bone;• the parietal support portion partially forms the posterior support portion;• the posterior support portion is connected to the occipital strap portion;• the occipital strap portion is connected to the posterior support portion by passing through one or more guides provided to the posterior support portion;• the posterior support portion is annular in shape;• the posterior support portion is formed from foam and / or textile materials;• the posterior support portion is thermoformed;• the posterior support portion is constructed to have a predetermined curved shape;A2578192 11.8 15• the predetermined curved shape of the posterior support portion comprises curvature in two orthogonal directions;• the posterior support portion comprises a superior portion and an inferior portion separated by a hinge region on each side of the posterior support portion, each hinge region constructed and arranged to encourage bending to occur at the hinge region;• the hinge region is constructed to have greater extensibility than the superior portion and the inferior portion of the posterior support portion;• the parietal strap portion comprises a cable routed therethrough;• the cable is routed between two layers of the parietal strap portion;• the band strap portion comprises a cable routed therethrough; and / or• the cable is routed between two layers of the band strap portion.

[0076] A positioning and stabilising structure for a patient interface, the patient interface comprising a flow generator casing, the positioning and stabilising structure constructed and arranged to hold the patient interface in an operable position on the user’s head in use, the positioning and stabilising structure comprising: a band strap portion constructed and arranged to encircle the user’s head in use, the band strap portion being connected to each one a pair of arms extending posteriorly from the flow generator casing on respective sides thereof, the band strap portion forming: a frontal strap portion constructed and arranged to engage the user’s head in use in a region overlying the frontal bone of the user’s head; and an occipital strap portion configured to engage the user’s head at a region overlying or lying inferior to the occipital bone of the user’s head in use; a pair of rigidisers provided to respective lateral sides of the occipital strap portion, each rigidiser fixedly connected to a respective one of the pair of arms in use.

[0077] In examples:• each of the rigidisers curves inferiorly away from the respective arm;A2578192 11.8 16• each of the rigidisers comprises a posterior end;• each of the rigidisers curves medially proximate the respective posterior end;• the respective posterior ends of the rigidisers are spaced apart in use;• each rigidiser is provided internally to the occipital strap portion;• the occipital strap portion is formed at least partially from foam;• the occipital strap portion comprises one or more textile outer layers;• the occipital strap portion is adjustable in length;• the occipital strap portion comprises a pair of anterior portions located on respective lateral sides of the user’s head in use and a posterior portion connecting the anterior portions of the occipital strap portion;• the posterior portion of the occipital strap portion comprises an unextended length that is selectively adjustable;• the posterior portion of the occipital strap portion is elastically extendable;• the positioning and stabilising structure comprises a parietal strap portion constructed and arranged to engage the user’ s head in use in a region overlying the parietal bones of the user’s head;• the parietal strap portion is connected to the band strap portion;• the parietal strap portion is formed at least partially from foam;• the parietal strap portion comprises one or more textile outer layers;• the parietal strap portion is adjustable in length;• the parietal strap portion comprises a pair of anterior portions located on respective lateral sides of the user’s head in use and a posterior portion connecting the anterior portions of the parietal strap portion;• the posterior portion of the parietal strap portion comprises an unextended length that is selectively adjustable;• the posterior portion of the parietal strap portion is elastically extendable;• the frontal strap portion of the positioning and stabilising structure is connected the flow generator casing in use to support at least some weight of the patient interface;• the patient interface comprises a frontal connector constructed and arranged to connect between the frontal strap portion of the positioning and stabilising structure and each of the arms to support at least some weight of the patient interface in use via the arms;A2578192 11.8 17• the frontal connector comprises a pair of lateral portions each extending towards and attaching to a respective one of the arms; and / or• the frontal connector is attached to a forwardmost portion of the each of the arms.

[0078] In further examples:• the positioning and stabilising structure comprises a parietal strap portion constructed and arranged to engage the user’ s head in use in a region overlying the parietal bones of the user’s head; wherein the occipital strap portion comprises a pair of anterior portions located on respective lateral sides of the user’s head in use and a posterior portion connecting the anterior portions of the occipital strap portion, and wherein the parietal strap portion comprises a pair of anterior portions located on respective lateral sides of the user’s head in use and a posterior portion connecting the anterior portions of the parietal strap portion;• each anterior portion of the occipital strap portion is integrally formed with a respective one of the anterior portions of the parietal strap portion; and / or• each anterior portion of the occipital strap portion is integrally formed with the frontal strap portion.

[0079] Another aspect of the present technology relates to a patient interface for treating a patient having a respiratory disorder, comprising: a respiratory pressure therapy (RPT) device including an electric blower configured to generate pressurized breathable air; a seal -forming structure configured to form a seal against the patient’s face and deliver a flow of breathable air to an entrance to the patient’s airways, the sealforming structure at least partially defining a plenum chamber configured to receive the pressurized air; a flow generator casing that at least partly encloses the electric blower and is connected to the plenum chamber, the casing including at least one air opening to receive ambient air for delivery to the RPT device; andA2578192 11.8 18a positioning and stabilising structure configured to maintain the seal-forming structure and the blower in a therapeutically effective position, the positioning and stabilising structure comprising: a pair of arms attached in use to the flow generator casing on respective sides thereof, the arms extending posteriorly from the flow generator casing; a band strap portion constructed and arranged to encircle the user’s head in use, the band strap portion being connected to each of the pair of arms in use, the band strap portion forming: a frontal strap portion constructed and arranged to engage the user’s head in use in a region overlying the frontal bone of the user’s head; and an occipital strap portion configured to engage the user’s head at a region overlying or lying inferior to the occipital bone of the user’s head in use; a pair of rigidisers provided to respective lateral sides of the occipital strap portion, each rigidiser fixedly connected to a respective one of the pair of arms in use.

[0080] A positioning and stabilising structure for a patient interface, the positioning and stabilising structure constructed and arranged to hold the patient interface in an operable position on the user’s head in use, the positioning and stabilising structure comprising: a pair of lateral portions each constructed and arranged to be positioned on a respective lateral side of the user’s head in use, wherein: each lateral portion comprises a respective one of a pair of arm connection portions each configured to be connected to a respective one of a pair of arms extending posteriorly from the patient interface on respective sides of the user’s head; and each lateral portion comprises a rigidised portion being stiffer than one or more adjacent portions;A2578192 11.8 19a frontal strap portion formed at least partially by the lateral portions, the frontal strap portion being constructed and arranged to engage the user’s head in use in a region overlying the frontal bone of the user’s head; a parietal strap portion formed at least partially by the lateral portions, the parietal strap portion constructed and arranged to engage the user’s head at a region overlying the parietal bones of the user’s head in use; an occipital strap portion formed at least partially by the lateral portions, the occipital strap portion constructed and arranged to engage the user’s head at a region overlying or lying inferior to the occipital bone of the user’s head in use; wherein each rigidised portion comprises a first portion located within the frontal strap portion, a second portion located within the parietal strap portion and a third portion located within the occipital strap portion.

[0081] In examples:• the lateral portions are able to conform to the shape of the user’s head;• in each rigidised portion, the first portion, the second portion and the third portion of said rigidised portion are all able to flex with respect to each other;• in each lateral portion, the respective rigidised portion extends from proximate the respective arm connection portion into each of the frontal strap portion, the parietal strap portion and the occipital strap portion;• each arm connection portion is constructed and arranged to fixedly connect to the respective one of the pair of arms extending posteriorly from the patient interface substantially without permitting rotation of the respective arm with respect to the arm connection portion;• the arm connection portions are constructed and arranged to fixedly connect to respective arms of the pair of arms extending posteriorly from the patient interface substantially without permitting rotation of the respective arms with respect to the rigidised portions;• in use, the positioning and stabilising structure is able to support substantially the entire weight of the patient interface via the arm connection portions;A2578192 11.8 20• the arm connection portions are constructed and arranged to form snap fit connections with the arms extending from the patient interface;• each lateral portion is at least partially formed in a layered construction;• the layered construction comprises a user-facing layer facing the user’s head in use and a rigi diser on the opposite side of the user-facing layer to the user’s head in use, the rigidiser forming the rigidised portion of the respective lateral portion and constructed and arranged to stiffen the respective lateral portion in the rigidised portion;• the user-facing layer comprises a textile material forming a user-facing surface;• the user-facing layer comprises a laminate comprising a foam layer and the textile material;• the rigidiser is formed from a polymer material;• the rigidiser is formed by injection moulding;• the rigidiser is formed in a non-planar shape and imparts a three-dimensional curved shape to the respective lateral portion;• the three-dimensional curved shape imparted to the lateral portions approximates curvature of a head surface that each lateral portion engages in use;• the rigidiser is able to flex away from the non-planar shape in use to conform to the shape of the user’s head;• the layered construction comprises a non-user facing layer on an opposite side of the rigidiser to the user-facing layer;• the non-user facing layer comprises a textile material forming a non-user facing surface;• the non-user facing layer comprises a laminate comprising a foam layer and the textile material;• regions of the lateral portion not occupied by the rigidiser are formed at least partially by the user-facing layer and the non-user facing layer;• the layered construction comprises at least one stiffening layer proximate the arm connection portion;• the stiffening layer surrounds the arm connection portion;• the stiffening layer overlaps with the rigidiser;A2578192 11.8 21• the layered construction comprises two stiffening layers, the two stiffening layers overlapping with the rigidiser, a portion of the rigidiser being between the two stiffening layers;• each of the at least one stiffening layer comprises a stiffening mesh;• the frontal strap portion is adjustable in length;• the frontal strap portion comprises a first portion extending from one of the lateral portions, the first portion passing through an opening provided to the other of the lateral portions and being secured back to itself;• the parietal strap portion is adjustable in length;• the parietal strap portion comprises a first portion extending from one of the lateral portions, the first portion passing through an opening provided to the other of the lateral portions and being secured back to itself;• the occipital strap portion is adjustable in length;• the occipital strap portion comprises a first portion extending from one of the lateral portions, the first portion passing through an opening provided to the other of the lateral portions and being secured back to itself;• the parietal strap portion is constructed and arranged to support one or more counterweights;• the parietal strap portion is constructed and arranged to support a pair of counterweights, each spaced from and located on opposing sides of the mid- sagittal plane of the user’s head in use;• the lateral portions are constructed and arranged to support the pair of counterweights in the parietal strap portion;• the one or more counterweights are configured to attach to the parietal strap portion with a hook-and-loop connection;• the occipital strap portion is constructed and arranged to support one or more counterweights;• the occipital strap portion is constructed and arranged to support a pair of counterweights, each spaced from and located on opposing sides of the mid- sagittal plane of the user’s head in use;• the lateral portions are constructed and arranged to support the pair of counterweights in the occipital strap portion; and / orA2578192 11.8 22• the one or more counterweights are configured to attach to the occipital strap portion with a hook-and-loop connection.

[0082] A positioning and stabilising structure for a patient interface, the positioning and stabilising structure constructed and arranged to hold the patient interface in an operable position on the user’s head in use, the positioning and stabilising structure comprising: a pair of lateral portions each constructed and arranged to be positioned on a respective lateral side of the user’s head in use, wherein: each lateral portion comprises a respective one of a pair of arm connection portions each configured to be connected to a respective one of a pair of arms extending posteriorly from the patient interface on respective sides of the user’s head; and each lateral portion comprises a rigidised portion being stiffer than one or more adjacent portions; a frontal strap portion formed at least partially by the lateral portions, the frontal strap portion being constructed and arranged to engage the user’s head in use in a region overlying the frontal bone of the user’s head; a parietal strap portion formed at least partially by the lateral portions, the parietal strap portion constructed and arranged to engage the user’s head at a region overlying the parietal bones of the user’s head in use; an occipital strap portion formed at least partially by the lateral portions, the occipital strap portion constructed and arranged to engage the user’s head at a region overlying or lying inferior to the occipital bone of the user’s head in use; wherein each arm connection portion is constructed and arranged to fixedly connect to the respective one of the pair of arms extending posteriorly from the patient interface substantially without permitting rotation of the respective arm with respect to the arm connection portion.

[0083] In examples:A2578192 11.8 23• the arm connection portions are constructed and arranged to fixedly connect to respective arms of the pair of arms extending posteriorly from the patient interface substantially without permitting rotation of the respective arms with respect to the rigidised portions;• in use, the positioning and stabilising structure is able to support substantially the entire weight of the patient interface via the arm connection portions;• the arm connection portions are constructed and arranged to form snap fit connections with the arms extending from the patient interface;• each rigidised portion comprises a first portion located within the frontal strap portion, a second portion located within the parietal strap portion and a third portion located within the occipital strap portion;• the lateral portions are able to conform to the shape of the user’s head;• in each rigidised portion, the first portion, the second portion and the third portion of said rigidised portion are all able to flex with respect to each other; and / or• in each lateral portion, the respective rigidised portion extends from proximate the respective arm connection portion into each of the frontal strap portion, the parietal strap portion and the occipital strap portion.

[0084] The present technology may also be directed toward providing interfacing structures used in the supporting, cushioning, stabilizing, positioning, and / or sealing a head-mounted display in opposing relation with the user’s face.

[0085] Another aspect relates to apparatuses used in the supporting, cushioning, stabilizing, positioning, and / or sealing a head-mounted display in opposing relation with the user’s face.

[0086] Another aspect relates to methods used in supporting, cushioning, stabilizing, positioning, and / or sealing a head-mounted display in opposing relation with the user’s face.

[0087] An aspect of one form of the present technology relates to a patient interface combining the features of AR / VR and respiratory therapy.

[0088] An aspect of one form of the present technology relates to a patient interface for treating a patient with a respiratory disorder includes an RPT device including an electric blower configured to generate pressurized breathable air, a user interface structure configured to engage against the patient’s face, the user interfaceA2578192 11.8 24structure at least partially forming a plenum chamber configured to receive the pressurized breathable air, a head-mounted interface configured to substantially cover the eyes of the patient, a flow generator casing that at least partly encloses the headmounted interface and the electric blower and is connected to the plenum chamber, the flow generator casing including at least one air opening to receive ambient air for delivery to the RPT device, and a positioning and stabilising structure configured to maintain the user interface structure in a therapeutically effective position.

[0089] In an example, the head-mounted interface is the form of a head-mounted display interface configured to generate a computer-generated image to the patient. In an alternative example, the head-mounted interface may not include any display or screen and may not generate any computer-generated image.

[0090] In an example, the user interface structure includes a stability cushion component and a therapy cushion component that is separate and distinct from the stability cushion component. The therapy cushion component may at least partially form a seal-forming structure.

[0091] In an example, the stability cushion component is configured to extend about a periphery of the patient’s eyes and form a viewing opening to the headmounted interface.

[0092] In an example, the therapy cushion component is configured to form the plenum chamber and form a seal with the patient’s nose and / or mouth.

[0093] In an example, the stability cushion component is configured to removably and interchangeably couple with the flow generator casing, and the therapy cushion component is configured to removably and interchangeably couple with the stability cushion component and / or the flow generator casing.

[0094] In an example, the stability cushion component is configured to engage the patient’s face to provide substantially complete sealing around the patient’s eyes.

[0095] In an example, the therapy cushion component is configured to removably and interchangeably couple with the flow generator casing.

[0096] In an example, the therapy cushion component is a nasal cushion including a silicone membrane configured to form a seal with the patient’s nose.

[0097] In an example, the stability cushion component is provided in one size and / or type and the therapy cushion component is provided in multiple sizes and / or types.A2578192 11.8 25

[0098] An aspect of one form of the present technology relates to a therapy cushion component for a patient interface configured to treat a patient with a respiratory disorder, the therapy cushion component is configured to form a plenum chamber and form a seal with the patient’s nose and / or mouth.

[0099] An aspect of one form of the present technology relates to full-face patient interface for respiratory therapy including a seal-forming structure with a two-part cushion construction.

[0100] In an example, the seal -forming structure includes a nasal cushion component and a mouth cushion component that is separate and distinct from the nasal cushion component.

[0101] In an example, the nasal cushion component is configured to removably and interchangeably couple with the casing, and the mouth cushion component is configured to removably and interchangeably couple with the casing independent from the nasal cushion component.

[0102] An aspect of one form of the present technology is a portable RPT device that may be carried by a person, e.g., around the home of the person.

[0103] The methods, systems, devices and apparatus described may be implemented so as to improve the functionality of a processor, such as a processor of a specific purpose computer, respiratory monitor and / or a respiratory therapy apparatus. Moreover, the described methods, systems, devices and apparatus can provide improvements in the technological field of automated management, monitoring and / or treatment of respiratory conditions, including, for example, sleep disordered breathing.

[0104] Of course, portions of the aspects may form sub-aspects of the present technology. Also, various ones of the sub-aspects and / or aspects may be combined in various manners and also constitute additional aspects or sub-aspects of the present technology.

[0105] Other features of the technology will be apparent from consideration of the information contained in the following detailed description, abstract, drawings and claims.A2578192 11.8 264 BRIEF DESCRIPTION OF THE DRAWINGS

[0106] 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

[0107] Fig. 1 A shows a system including a patient 1000 wearing a patient interface 3000, in the form of nasal pillows, receiving a supply of air at positive pressure from an RPT device 4000. Air from the RPT device 4000 is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000. A bed partner 1100 is also shown. The patient is sleeping in a supine sleeping position.

[0108] 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.

[0109] 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

[0110] Fig. 2 A shows an overview of a human respiratory system including the nasal and oral cavities, the larynx, vocal folds, oesophagus, trachea, bronchus, lung, alveolar sacs, heart and diaphragm.

[0111] 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.

[0112] 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.

[0113] 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,A2578192 11.8 27supramenton, nasal ridge, alar crest point, otobasion superior and otobasion inferior. Also indicated are the directions superior & inferior, and anterior & posterior.

[0114] 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.

[0115] 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.

[0116] Fig. 2G shows a side view of the superficial features of a nose.

[0117] 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.

[0118] 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.

[0119] Fig. 2 J shows a front view of the bones of a skull including the frontal, nasal and zygomatic bones. Nasal concha are indicated, as are the maxilla, and mandible.

[0120] 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.

[0121] Fig. 2L shows an anterolateral view of a nose.

[0122] Fig. 2M shows another a view of the face with several features of surface anatomy identified including the epicranius, the sphenoid, the nasal ridge, the outer and inner cheek regions, the zygomatic arch, and the alar crest.

[0123] Fig. 2N shows a side view of the face with several features of surface anatomy identified including the epicranius, the sphenoid, the nasal ridge, the outer and inner cheek regions, the zygomatic arch, and the alar crest.4.3 PATIENT INTERFACE

[0124] Fig. 3 shows a patient interface in the form of a nasal mask in accordance with one form of the present technology.A2578192 11.8 284.4 INTERFACES AND HEADGEAR

[0125] Fig. 4A shows a side view of a head-mounted display system according to another example of the present technology.

[0126] Fig. 4B shows a side view of a head-mounted display system according to another example of the present technology.

[0127] Fig. 4C shows a side view of a head-mounted display system according to another example of the present technology.

[0128] Fig. 4D shows a side view of a head-mounted display system according to another example of the present technology.

[0129] Fig. 4E shows a side view of a head-mounted display system according to another example of the present technology.

[0130] Fig. 4F shows a perspective view of a positioning and stabilising structure for a head-mounted display system according to another example of the present technology.

[0131] Fig. 4G shows a side view of a lateral portion of the positioning and stabilising structure shown in Fig. 4F.

[0132] Fig. 4H shows a cross-section view through section A-A as labelled in Fig. 4G.

[0133] Fig. 41 shows an exploded view of the lateral portion shown in Fig. 4G.

[0134] Fig. 4J shows a side view of the lateral portion shown in Fig. 4G with certain portions indicated.

[0135] Fig. 4K shows a side view of a rigidiser of the lateral portion shown in Fig. 4G.

[0136] Fig. 4L shows a side view of a first lateral portion of the positioning and stabilising structure shown in Fig. 4F.

[0137] Fig. 4M shows a side view of a second lateral portion of the positioning and stabilising structure shown in Fig. 4F.A2578192 11.8 29

[0138] Fig. 4N shows a perspective view of the positioning and stabilising structure shown in Fig. 4F with counterweights attached.

[0139] Fig. 40 shows a side view of a patient interface including the positioning and stabilising structure shown in Fig. 4F when worn by a user.

[0140] Fig. 5 is a front perspective view of a head-mounted display.

[0141] Fig. 6 is a rear perspective view of the head-mounted display of Fig. 5.

[0142] Fig. 7 is a perspective view of a patient interface including an RPT device, a head-mounted display interface and a user interface structure on a patient’s head according to an example of the present technology.

[0143] Fig. 8 is a side view of the patient interface of Fig. 7 on a patient’s head according to an example of the present technology.

[0144] Fig. 9 is a front view of the patient interface of Fig. 7 on a patient’s head according to an example of the present technology.5 DETAILED DESCRIPTION OF EXAMPLES OF THETECHNOLOGY

[0145] 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.

[0146] 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

[0147] 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.

[0148] 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.A2578192 11.8 30

[0149] In certain examples of the present technology, mouth breathing is limited, restricted or prevented.5.2 RESPIRATORY THERAPY SYSTEMS

[0150] In one form, the present technology comprises a respiratory therapy system for treating a respiratory disorder. The respiratory therapy system may comprise an RPT device 4000 for supplying a flow of air to the patient 1000 via an air circuit 4170 and a patient interface 3000.5.3 PATIENT INTERFACE

[0151] A non-invasive patient interface 3000 in accordance with one aspect of the present technology comprises the following functional aspects: a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilising structure 3300, a vent 3400, one form of connection port 3600 for connection to air circuit 4170, and a forehead support 3700. In some forms a functional aspect may be provided by one or more physical components. In 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 sealed patient interface 3000 is therefore suitable for delivery of positive pressure therapy.

[0152] 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.

[0153] 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.

[0154] 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 of at least 2 cmH20 with respect to ambient.

[0155] 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 of at least 4 cmH20 with respect to ambient.

[0156] 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 of at least 6 cmH20 with respect to ambient.A2578192 11.8 31

[0157] 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 of at least 10 cmH20 with respect to ambient.

[0158] 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 of at least 20 cmH20 with respect to ambient.5.3.1 Seal-forming structure

[0159] In one form of the present technology, a seal-forming structure 3100 provides a target seal-forming region, and may additionally provide a cushioning function. The target seal-forming region is a region on the seal -forming structure 3100 where sealing may occur. The region where sealing actually occurs- the actual sealing surface- may change within a given treatment session, from day to day, and from patient to patient, depending on a range of factors including for example, where the patient interface was placed on the face, tension in the positioning and stabilising structure and the shape of a patient’s face.

[0160] In one form the target seal -forming region is located on an outside surface of the seal-forming structure 3100.

[0161] In certain forms of the present technology, the seal-forming structure 3100 is constructed from a biocompatible material, e.g. silicone rubber.

[0162] A seal -forming structure 3100 in accordance with the present technology may be constructed from a soft, flexible, resilient material such as silicone.

[0163] 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

[0164] 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 assistedA2578192 11.8 32mechanism may act in conjunction with elastic tension in the positioning and stabilising structure.

[0165] In one form, the seal -forming structure 3100 comprises a sealing flange and a support flange. The sealing flange comprises a relatively thin member with a thickness of less than about 1mm, for example about 0.25mm to about 0.45mm, which extends around the perimeter of the plenum chamber 3200. Support flange may be relatively thicker than the sealing flange. The support flange is disposed between the sealing flange and the marginal edge of the plenum chamber 3200, and extends at least part of the way around the perimeter. The support flange is or includes a springlike element and functions to support the sealing flange from buckling in use.

[0166] In one form, the seal -forming structure may comprise a compression sealing portion or a gasket sealing portion. In use the compression sealing portion, or the gasket sealing portion is constructed and arranged to be in compression, e.g. as a result of elastic tension in the positioning and stabilising structure.

[0167] In one form, the seal -forming structure comprises a tension portion. In use, the tension portion is held in tension, e.g. by adjacent regions of the sealing flange.

[0168] In one form, the seal -forming structure comprises a region having a tacky or adhesive surface.

[0169] In certain forms of the present technology, a seal -forming structure may comprise one or more of a pressure-assisted sealing flange, a compression sealing portion, a gasket sealing portion, a tension portion, and a portion having a tacky or adhesive surface.5.3.1.2 Nose bridge or nose ridge region

[0170] 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.

[0171] 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

[0172] 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.A2578192 11.8 33

[0173] 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

[0174] In one form the non-invasive patient interface 3000 comprises a sealforming structure that forms a seal in use on a chin-region of the patient's face.

[0175] In one form, the seal -forming structure includes a saddle-shaped region constructed to form a seal in use on a chin-region of the patient's face.5.3.1.5 Forehead region

[0176] 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

[0177] In one form the seal-forming structure of the non-invasive patient interface 3000 comprises a pair of nasal puffs, or nasal pillows, each nasal puff or nasal pillow being constructed and arranged to form a seal with a respective naris of the nose of a patient.

[0178] Nasal pillows in accordance with an aspect of the present technology include: a frusto-cone, at least a portion of which forms a seal on an underside of the patient's nose, a stalk, a flexible region on the underside of the frusto-cone and connecting the frusto-cone to the stalk. In addition, the structure to which the nasal pillow of the present technology is connected includes a flexible region adjacent the base of the stalk. The flexible regions can act in concert to facilitate a universal joint structure that is accommodating of relative movement both displacement and angular of the frusto-cone and the structure to which the nasal pillow is connected. For example, the frusto-cone may be axially displaced towards the structure to which the stalk is connected.5.3.2 Plenum chamber

[0179] 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. InA2578192 11.8 34some forms, the plenum chamber 3200 and the seal -forming structure 3100 are formed from a single homogeneous piece of material.

[0180] In certain forms of the present technology, the plenum chamber 3200 does not cover the eyes of the patient in use. In other words, the eyes are outside the pressurised volume defined by the plenum chamber. Such forms tend to be less obtrusive and / or more comfortable for the wearer, which can improve compliance with therapy.

[0181] In certain forms of the present technology, the plenum chamber 3200 is constructed from a transparent material, e.g. a transparent polycarbonate. The use of a transparent material can reduce the obtrusiveness of the patient interface, and help improve compliance with therapy. The use of a transparent material can aid a clinician to observe how the patient interface is located and functioning.

[0182] In certain forms of the present technology, the plenum chamber 3200 is constructed from a translucent material. The use of a translucent material can reduce the obtrusiveness of the patient interface, and help improve compliance with therapy.5.3.3 Positioning and stabilising structure

[0183] 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.

[0184] 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.

[0185] 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.

[0186] 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.

[0187] 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 actualA2578192 11.8 35bulk 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.

[0188] 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.

[0189] 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.

[0190] 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.

[0191] In one form of the present technology, a positioning and stabilising structure 3300 comprises a strap constructed from a laminate of a fabric patientcontacting layer, a foam inner layer and a fabric outer layer. In one form, the foam is porous to allow moisture, (e.g., sweat), to pass through the strap. In one form, the fabric outer layer comprises loop material to engage with a hook material portion.

[0192] In certain forms of the present technology, a positioning and stabilising structure 3300 comprises a strap that is extensible, e.g. resiliently extensible. For example the strap may be configured in use to be in tension, and to direct a force to draw a seal-forming structure into sealing contact with a portion of a patient’s face. In an example the strap may be configured as a tie.

[0193] 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 otobasionA2578192 11.8 36superior of the patient’s head and overlays a portion of a parietal bone without overlaying the occipital bone.

[0194] In one form of the present technology suitable for a nasal-only mask or for a full-face mask, the positioning and stabilising structure includes a second tie, the second tie being constructed and arranged so that in use at least a portion of a superior edge thereof passes inferior to an otobasion inferior of the patient’s head and overlays or lies inferior to the occipital bone of the patient’s head.

[0195] 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.

[0196] 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.

[0197] 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,

[0198] In certain forms of the present technology, a system is provided comprising more than one positioning and stabilizing 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 stabilizing 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.5.3.4 Vent

[0199] 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.

[0200] 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.A2578192 11.8 37

[0201] 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.

[0202] 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.5.3.5 Decoupling structure(s)

[0203] In 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

[0204] Connection port 3600 allows for connection to the air circuit 4170.5.3.7 Forehead support

[0205] In one form, the patient interface 3000 includes a forehead support 3700.5.3.8 Anti-asphyxia valve

[0206] In one form, the patient interface 3000 includes an anti-asphyxia valve.5.3.9 Ports

[0207] 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 Self-contained unit

[0208] As illustrated in Figs. 40 and 5-9, some forms of the patient interface may be self-contained units. For example, the patient interfaces may not need to be connected to an external device to receive a flow of pressurized air. Instead, the patient interface itself may include a motor for delivering pressurized airflow directly to a patient. International (PCT) Patent Application No. PCT / AU2024 / 050419 having International Publication No. WO 2024 / 227220 Al, which is hereby incorporated by reference in its entirety, describes technology, including patient interfaces comprising flow generators, which may be applied to patient interfaces or head-mounted display systems described herein.

[0209] In some forms, this may enable the patient interface to be more portable, which may be particularly beneficial for patients who travel. For example, the patientA2578192 11.8 38may be able to pack a smaller, more portable component. This may promote the continuance of therapy while the patient is away from home.

[0210] In some forms, the self-contained patient interface may promote better sleep in the patient or in a bed partner. For example, the patient may not be tethered to an RPT device, which could restrict movement while sleeping. This may allow the patient to roll or otherwise move while sleeping without being constrained. Similarly, the patient’s bed partner may experience a better sleep if the patient is able to sleep throughout the night.

[0211] In certain forms, a patient (and / or the patient’s bed partner) may dislike the intrusiveness of wires, tubes, and / or cords, and may find the medical appearance of the patient interface aesthetically unappealing. This could lead to lower compliance with the therapy. By reducing the external attachments on the self-contained patient interface, a patient may be more likely to use the patient interface. For example, as described below, the material of the patient interface, combined with the lack of external attachments, may reduce the medical feel of the patient interface.

[0212] In some forms, providing a single unit may be more intuitive for a patient to use. For example, the patient may need to interact with a single device, which may simplify the steps necessary to learn how to use the device.

[0213] As described below, the patient interfaces illustrated in Figs. 40 and 5 to 9 may be similar to the patient interface 3000 described above (see e.g., Fig. 3 A), and only some similarities and differences may be described.5.3.10.1 Full-face interface

[0214] In some examples the patient interface is a full-face patient interface. For example, the patient interface may form a seal around the patient’s nares and the patient’s mouth so that pressurized air may be delivered to the patient’s airways through either the patient’s nose and / or the patient’s mouth.5.3.10.2 Nasal interface

[0215] In some examples the patient interface is a nasal patient interface. For example, the patient interface may form a seal around the patient’s nares so that pressurized air may be delivered to the patient’s airways through the patient’s nose. A seal may not be formed around the patient’s mouth so that the patient’s mouth remains exposed to ambient pressure. Figs. 40 and 5-9 illustrate such patient interfaces.A2578192 11.8 395.4 AR / VR

[0216] A user may experience augmented reality (AR) and / or virtual reality (VR) with the use of a head-mounted display interface. Examples of head -mounted display interfaces are disclosed in WO 2021 / 137766, WO 2021 / 189096, U.S. 2021 / 0302749, and U.S. 2021 / 0302748, which are each herein incorporated by reference in their entirety.

[0217] As shown in Figs. 5 and 6, a head-mounted display interface 11000 may include a user interface structure 11100, a display unit housing 11200, and a support structure 11300. The head-mounted display interface 11000 may output a computergenerated image to the user wearing the head-mounted display interface 11000.

[0218] In some forms, the user interface structure 11100 may be constructed from a comfortable material (e.g., foam, textile, silicone, etc.) and may contact the user’s face. The user interface structure 11100 may assist in dispersing the force applied to the user’s face so that the head-mounted display interface 11000 is more comfortable to wear.

[0219] The display unit housing 11200 may include the electrical components for outputting the computer generated image. The display unit housing 11200 may be formed from a rigid or semi-rigid material in order to protect the electrical components.

[0220] The support structure 11300 may be similar to the positioning and stabilising structures described above. For example, the support structure 11300 may include straps constructed at least partially from textile materials. The straps may be able to stretch in order to fit different sized users. The straps may also be rigidized or include a rigidizer in order to provide stiffness and / or stability.

[0221] In some forms, the head-mounted display interface 1100 may include a battery (e.g., a rechargeable battery) in the display unit housing 11200. The headmounted display interface may be removably connected to a charger in order to recharge the battery.

[0222] In other forms, the head-mounted display interface 11000 may include a port (not shown) for receiving a power cord connected to a battery.

[0223] As illustrated in Fig. 5, some forms of a head-mounted display interface 11000 may include at least one opening 11104 in the user interface structure 11000. When the user dons the head -mounted display interface 11000, the at least one opening 11104 may be aligned with the user’s nose. For example, a single openingA2578192 11.8 40may align with both nares, or there may be separate openings for each naris. The illustrated example also shows a user interface structure 11000 that cradles the user’s nose. Alternatively, the user interface structure 11000 may include a structure around the at least one opening 11104 that is received within the user’s naris.

[0224] In some forms, the display unit housing 11200 may include a blower. The blower in the display unit housing 11200 may generate a flow of pressurized breathable gas, which may be output through the at least one opening 11104. The patient may inhale the pressurized gas through their nose as described in any of the examples above. Thus, the user interface structure 11000 may seal around at least a part of the user’s face (e.g., to prevent leaks of pressurized air). Additionally, although not illustrated, the opening 11104 may extend around the user’s mouth so that the user could also inhale the pressurized air through their mouth.5.5 COMBINATION INTERFACES

[0225] In some forms, the head-mounted display interface 11000 may combine the features of AR / VR and respiratory therapy. For example, a patient may use the head-mounted display interface 11000 to receive pressurized air in order to alleviate a breathing disorder, in which case the head-mounted display interface is also a patient interface. Simultaneously, the user may view a computer generated image output from the display unit housing 11200. Utilizing AR / VR with the therapy may make the therapy and wearing a patient interface more comfortable (e.g., thus improving patient compliance). For example, the computer generated image may assist the patient in falling to sleep faster in order to more effectively take advantage of the therapy.

[0226] Figs. 40 and 7-9 show patient interfaces 12000 combining the features of AR / VR and respiratory therapy according to further examples of the present technology. Figs. 4A-4E show head-mounted display systems 1000 with positioning and stabilising structures 1300 that may be applied to the head-mounted display interface 11000 shown in Figs. 5-6 or the patient interface 12000 shown in Figs. 7-9. Similarly, Figs. 4F-4N show a positioning and stabilising structure 1300 that may be applied to the patient interface 12000 shown in Figs. 7-9, as shown in Fig. 40. Alternatively, in the examples shown in Figs. 4A-4E the head-mounted display unit 1200 may be replaced by a the flow generator casing 12200 and user interface structure 12100 to form a patient interface 12000 having the positioning and stabilising structure 1300 shown in any of Figs. 4A-4E. The patient interface 12000A2578192 11.8 41may include a respiratory pressure therapy (RPT) device including an electric blower configured to generate pressurized breathable air, a head-mounted display interface configured to generate a computer-generated image to the patient, a user interface structure 12100 configured to engage with a patient’s face, a flow generator casing 12200 (also referred to as a display unit housing) that at least partly encloses the headmounted display interface and the electric blower, and a positioning and stabilising structure 12300 or 1300 (also referred to as a support structure) configured to maintain the user interface structure 12100 in a therapeutically effective position. In some forms, the head-mounted display interface may be in the form of a headmounted interface configured to substantially cover the eyes of the patient. Such head-mounted interface may not include any display or screen and may not generate any computer-generated image.

[0227] The flow generator casing 12200 is configured to support components associated with respiratory therapy (e.g., blower, one or more batteries to power the blower, and a seal-forming structure (e.g. user interface structure 12100) along with components associated with AR / VR (e.g., display interface with electrical components for outputting a computer-generated image, interfacing structure 1100 and the like). In an example, the features associated with respiratory therapy may be integrated into existing space (e.g., the casing) occupied by AR / VR features, i.e., synergy between respiratory therapy and AR / VR. Thus, the patient interface 12000 according to an example of the present technology comprises a self-contained CPAP system (e.g., therapy cushion component and RPT device configured to deliver a flow of pressurized breathable air to the patient in a positive pressure range suitable for treatment of a respiratory disorder) along with an AR / VR system (e.g., stability cushion component and display interface) to enhance therapy (video and / or audio output). As noted above, in some forms, the CPAP system may be configured so that the head-mounted interface may not include any display or screen and may not generate any computer-generated image.5.5.1 Two-Part Cushion Component

[0228] An aspect of one form of the present technology relates to a user interface structure for a patient interface configured to treat a patient with a respiratory disorder, the user interface structure including a stability cushion component and a therapy cushion component that is separate and distinct from the stability cushionA2578192 11.8 42component. In the examples shown in Figs. 40 and 7-9, the user interface structure 12100 of the interface includes a multi-part construction. For example, the user interface structure 12100 includes a two-part cushion component, i.e., a stability cushion component 12700 and a therapy cushion component 12500 that is separate and distinct from the stability cushion component 12700. The stability cushion component 12700 may be configured to removably and interchangeably couple with the flow generator casing 12200, and the therapy cushion component 12500 may be configured to removably and interchangeably couple with the stability cushion component 12700 and / or the flow generator casing 12200. This arrangement separates the seal provided by the stability cushion component 12700 from the seal provided by the therapy cushion component 12500 so that they can be independently configured and designed for their specific functions, e.g., stability cushion component 12700 may be configured to enhance structure and stability for supporting the weight of the patient interface on the patient’s face whereas the therapy cushion component 12500 may be configured to enhance seal and comfort for respiratory therapy.5.5.1.1 Stability Cushion Component

[0229] An aspect of one form of the present technology relates to a stability cushion component for a patient interface configured to treat a patient with a respiratory disorder, the stability cushion component configured to extend about a periphery of the patient’s eyes. In an example, the stability cushion component 12700 is configured to extend about a periphery of the display interface (e.g., VR display) contained by the flow generator casing 12200, and form a viewing opening to the display interface. In use, the stability cushion component 12700 extends around a periphery of the user’s eyes, and may engage with the user’s face (e.g., along the user’s cheek and / or forehead) to provide substantially complete sealing around the user’s eyes (e.g., to at least partially block light from entering the flow generator casing 12200 in order to facilitate immersion in the use of the display interface). Moreover, the stability cushion component 12700 is configured and arranged to support the patient interface 12000 on the user’s face in a comfortable stable manner.

[0230] More detail on the stability cushion component 12700 can be found in WO2024227220 Al.A2578192 11.8 435.5.1.2 Therapy Cushion Component

[0231] An aspect of one form of the present technology relates to a therapy cushion component for a patient interface configured to treat a patient with a respiratory disorder, the therapy cushion component is configured to form a plenum chamber and form a seal with the patient’s nose and / or mouth. In an example, the therapy cushion component 12500 is configured to form a seal with the user’s nose and / or mouth, and to deliver the flow of pressurized breathable air from the blower to the patient’s nose and / or mouth. The therapy cushion component 12500 may repeatably and removably engage with the stability cushion component 12700 and / or the flow generator casing 12200.

[0232] More detail on the therapy cushion component 12500 can be found in WO2024227220 Al.5.5.1.3 Connection of Therapy Cushion Component to Stability Cushion Component

[0233] In some examples, the therapy cushion component 12500 and the stability cushion component 12700 include cooperating retaining structures to repeatably and removably connect the therapy cushion component 12500 to the stability cushion component 12700. In an example, the therapy cushion component 12500 is releasably connectable to the stability cushion component 12700 to facilitate replacement and / or cleaning, and to allow alternative therapy cushion components 12500 and stability cushion components 12700 to be connected to one another. Such arrangement allows multiple therapy cushion components 12500 (e.g., sizes and / or types) to be used with the stability cushion component 12700 and therefore provide a user interface structure 12100 suitable for most users.

[0234] In an example, the therapy cushion component is coupled with the stability cushion component to provide a substantially non-adjustable assembly in which adjustable movement between the therapy cushion component and the stability cushion component is substantially resisted.5.5.2 Positioning and Stabilising Structures

[0235] In some examples, the positioning and stabilising structure 12300 may be adjustably and removably connected to at least a portion of the flow generator casing 12200 to hold the patient interface 12000 in an operable position on the patient’s face.A2578192 11.8 44

[0236] In an example, as shown in Figs. 7-9, the positioning and stabilising structure 12300 may include a single side strap 12310 configured to extend along the sides of the patient’s head and pass over respective ears, e.g., to facilitate donning and adjustment. The side strap 12310 may include ends that adjustably connect (via a mechanical fastener, hook and look material, magnets, etc.) to respective sides of the flow generator casing 12200. In an example, each side of the flow generator casing 12200 may include a strap connector, e.g., cross-bar that forms a strap opening that respective ends of the side strap may be threaded through.

[0237] Figs. 4A-4O will now be described in more detail. Figs. 4A-4E show head-mounted display systems 1000 each comprising a head-mounted display unit 1200 and positioning and stabilising structure 1300. As noted above, the headmounted display unit 1200 may in some examples be replaced by a patient interface having features described herein, such as one of the patient interfaces 11000 or 12000 for example. Figs. 4F-4N show a positioning and stabilising structure 1300 for the patient interfaces 11000 or 12000 and Fig. 40 shows a patient interface 12000 according to an example of the present technology in which the positioning and stabilising structure 1300 is applied to the patient interface 12000 shown in Figs. 7-9.

[0238] The examples of Figs. 4A-4E and 4F-4O will be described with reference to both AR / VR components (as included in the examples shown in Figs. 4A-4E) and patient interface components (as included in the examples shown in Figs. 4F-4O and 7-9). It is to be understood that where any feature of a positioning and stabilising structure 1300 shown in one of Figs. 4A-4E is described with reference to a headmounted display system 1000 or components thereof (e.g. head-mounted display unit 1200 or display unit housing 1205), that feature may be applied to a patient interface such as the patient interface 12000 shown in Fig. 40 or shown in Figs. 7-9. Where references are made to both the head-mounted display system 1000 and patient interface 12000 (or to subcomponents such as the head-mounted display unit 1200 / display unit housing 1205 and flow generator casing 12200, or the interfacing structure 1100 or user interface structure 12100), the reference is to be understood to apply as the case may be.

[0239] Positioning and stabilising structures 1300 according to examples of the present technology, such as those that are shown in Figs. 4A-4O are constructed and arranged to hold the head -mounted display unit 1200 or patient interface 12000 in an operable position on the user’s head in use (e.g., such that the display is positioned inA2578192 11.8 45a viewing position anterior to the user’s eyes and such that the interfacing structure 1100 or user interface structure 12100 engages the user’s face to form a light seal, such as at least in forehead, sphenoid and cheek regions of the user’s face).

[0240] The interfacing structure 1100 or user interface structure 12100 may be configured to engage the user’s face around a periphery of the user’s eyes in use. The interfacing structure 1100 or user interface structure 12100 may be configured to engage the sides of the user’s face lateral of the user’s eyes and engage the user’s forehead in use. In some examples the interfacing structure 1100 or user interface structure 12100 may engage the user’s cheeks, the sides of the user’s face lateral of the user’s eyes and the user’s forehead. In some forms, the interfacing structure 1100 or user interface structure 12100 may engage the user’s face at regions overlying the user’s nose, maxilla, zygomatic bones, sphenoid bones and frontal bones

[0241] In some examples, the interfacing structure 1100 or user interface structure 12100 may comprise a face engaging flange, membrane, flap or the like (not shown) structured and arranged to be provided around a periphery of an eye region of the user’s face and configured to engage the user’s face in use. The face engaging flange may be flexible and resilient. In some examples, the face engaging flange is formed from an elastomeric material, for example silicone or TPE. In some examples the interfacing structure 1100 or user interface structure 12100 comprises a cushion. The cushion may be at least partially covered by the face engaging flange. The cushion may be formed from foam, silicone, gel or another suitable cushion material or structure constructed to behave as a cushion. In some examples, the interfacing structure 1100 or user interface structure 12100 comprises a cushion but no face engaging flange.

[0242] The interfacing structure 1100 or user interface structure 12100 may be configured to engage the user’s face and resist compression when the head-mounted display unit 1200 or patient interface 12000 is fastened securely to the user’s face, while remaining comfortable to the user. The cushion (if present) may contribute to the resilience of the interfacing structure 1100 or user interface structure 12100. The interfacing structure 1100 or user interface structure 12100 may comprise a pair of cheek portions configured to engage the user’s cheeks in use, a forehead portion configured to engage the user’s forehead in use, and a pair of sphenoid portionsA2578192 11.8 46located on respective lateral sides of the interfacing structure connecting between the forehead portion and the cheek portions and configured to engage the user’s head proximate the sphenoid bone.

[0243] In some examples, the interfacing structure 1100 or user interface structure 12100 comprises a nasal portion between the cheek portions. The nasal portion may be configured to engage the user’s nose in use and may be configured to at least partially block light from reaching the user’s eyes from the user’s nose region (e.g., block light travelling via a path proximate the surfaces of the user’s nose). The nasal portion may for example be configured to engage anterior, superior and / or lateral surfaces of the user’s nose in use. The nasal portion may be attached to the cheek portions.

[0244] In some examples, such as the examples shown in Figs. 4A-4E the headmounted display system 1000 comprises a pair of arms 1210 connected in use (e.g., fixedly attached or removably connected) to respective lateral sides of the display unit housing 1205 (e.g., to the housing and / or a pair of lateral support arms on the housing). In the example shown in Fig. 40 the patient interface 12000 comprises a pair of arms 1210 connected in use (e.g., fixedly attached or removably connected) to respective lateral sides of the flow generator casing 12100 (e.g., to the casing and / or a pair of lateral support arms on the housing). The arms 1210 may be constructed and arranged to project posteriorly from the display unit housing 1205 / flow generator casing 12100 on respective lateral sides of the user’s head in use. Anterior portions of the arms 1210 may include a connector (e.g., snap-fit connector, pin connection or the like) to facilitate removeable connection to the display unit housing 1205 / flow generator casing 12100. In other examples the arms 1210 may not be separable from the display unit housing 1205 / flow generator casing 12100.

[0245] The arms 1210 may be configured to resist bending about one or more axes and may therefore be described as rigidised or at least semi-rigid (i.e., semi-rigid or rigid). Rigidised portions of a positioning and stabilising structure 1300 or strap thereof may be rigidised if they are stiffened so as to be able to transfer forces other than tension to another portion of the positioning and stabilising structure 1300 or strap thereof, for example by providing resistance to bending or compression forces. The arms 1210 may comprise a textile outer layer and may be rigidised to beA2578192 11.8 47substantially rigid. In some examples the arms 1210 may comprise a substantially rigid component covered in a textile layer (e.g., textile on both sides or textile on one side). In some examples only a user-facing side of the arms 1210 comprises a textile layer.

[0246] In some examples each arm 1210 is at least partially covered by a textile sleeve. In some particular examples each arm 1210 is encapsulated within a textile sleeve. Partially or fully covering the arms 1210 may provide for comfortable contact between the arm 1210 and the user’s head, may be aesthetically pleasing, may provide for a perception of comfort and may conceal or protect other components provided to the arms 1210, such as electronics, sensors, transducers or the like, or wiring running along an arm 1210 to a posterior battery pack or any other components.

[0247] In some examples, the arms 1210 may be pivotably attached to the display unit housing 1205 or flow generator casing 12100, which may advantageously allow the angle of head-mounted display unit 1200 to be adjusted to suit the user’s particular anatomy. In other examples, the arms 1210 may be rotationally fixed with respect to the display unit housing 1205 / flow generator casing 12100.5.5.2.1 Rigidised parietal strap portion connected to arms

[0248] Figs. 4A-4D show examples of head -mounted display systems 1000. In each of these examples the head-mounted display system 1000 comprises a positioning and stabilising structure 1300 comprising a pair of arms 1210. The arms 1210 may be attached in use to a display unit housing 1205 on respective sides thereof. As illustrated, the arms 1210 extend posteriorly from the display unit housing 1205. The positioning and stabilising structure 1300 may alternatively be applied to patient interface 12000 shown in Figs. 40 and 7-9 and the following description is to be understood to also relate to such embodiments of the present technology.

[0249] The positioning and stabilising structure 1300 in each of these examples also comprises a parietal strap portion 1310 configured to engage the user’s head at a region overlying the parietal bones of the user’s head in use. As illustrated, the parietal strap portion 1310 is connected to each of the pair of arms 1210 in these examples. The parietal strap portion 1310 may be rigidised, e.g. it may be semi-rigid to resist bending in superior-inferior directions in use. The parietal strap portion 1310A2578192 11.8 48may also resist extension along its length (although may be selectively adjustable in length by the user).

[0250] The arms 1210 and parietal strap portion 1310 may together with the head-mounted display unit 1200 or patient interface 12000 form a rigidised loop encircling the lateral sides and posterior of the user’s head. The arms 1210 and parietal strap portion 1310 may resist superior and inferior bending and resist tension, to support at least some of the weight of the head-mounted display unit 1200 or patient interface 12000 and to hold it securely on the user’s head. However, the parietal strap portion 1310 may be constructed to be able to wrap comfortably around the user’s head in use. The parietal strap portion 1310 may for example have a thin cross section, and may be formed from a material that allows for medial / lateral bending.

[0251] In some forms of the present technology, the parietal strap portion 1310 comprises a predetermined shape whereby, on each lateral side of the user’s head, the parietal strap portion 1310 curves superiorly away from each of the arms 1210. Advantageously, this enables the parietal strap portion 1310 to engage a partially superior-facing surface region of the user’s head, instead of engaging a surface region behind the user’s head that faces only a substantially posterior direction. This may provide for good comfort when the user lies down facing up, as the bulk of the parietal strap portion 1310 is at least partially out of the way of the centre of the posterior of the user’s head. Additionally, or alternatively, this may provide for good stability when the user lies down facing up, as less force from the pillow or surface on which the user is lying may be applied to the parietal strap portion 1310. Such forces could otherwise be transferred through to the arms 1210 and to the head-mounted display unit 1200 or patient interface 12000, tending to force it out of engagement with the user’s face.

[0252] In the illustrated examples in Figs. 4A-4D, the parietal strap portion 1310 comprises a pair of anterior portions 1311 each connected to a respective one of the pair of arms 1210, and a posterior portion 1312 connected to the anterior portions 1311 and configured to engage the region overlying the parietal bones of the user’s head. The posterior portion 1312 of the parietal strap portion 1310 may be formed at least partially from foam. In other examples the parietal strap portion 1310 may beA2578192 11.8 49formed at least partially from an elastomeric material such as silicone, TPE or the like. In some examples the posterior portion 1312 of the parietal strap portion 1310 comprises a textile covering.

[0253] In the illustrated examples, the posterior portion 1312 of the parietal strap portion 1310 is constructed to have a predetermined curved shape. The posterior portion 1312 of the parietal strap portion 1310 may be dome shaped. Advantageously, a dome shape, e.g. curvature in two orthogonal directions to at least partially correspond to the shape of the user’s head, may provide for good engagement of the parietal strap portion 1310 to the user’s head. In particular, in comparison to a strap that is curved in only one direction, or not curved at all, a dome shape may spread the force between the strap and the user’s head out more evenly over the entire area of the strap. In the illustrated examples, the posterior portion 1312 of the parietal strap portion 1310 is wider in a medial portion thereof than at lateral ends thereof.

[0254] The parietal strap portion 1310 may be adjustable in length. In some examples, one or both of the anterior portions 1311 are moveable with respect to the posterior portion 1312 to adjust the length of the parietal strap portion 1310. For example, one or both of the anterior portions 1311 may be able to slide in the length direction of the posterior portion 1312 to extend from or retract into the posterior portion 1312. In some examples the extension / retraction is controlled by the user pushing / pulling the portions together or apart between indexed positions. In other examples a dial adjustment mechanism 1390 as shown in Fig. 4A is provided to the parietal strap portion 1310.

[0255] In some examples the parietal strap portion 1310 comprises one or more counterweights 1386. In the example shown in Fig. 4B, the parietal strap portion 1310 comprises a pair of counterweights 1386, each spaced from and located on opposing sides of the mid-sagittal plane of the user’s head in use. Advantageously, providing two counterweights 1386 to both sides of the parietal strap portion 1310 may result in better stability than one larger counterweight 1386 centrally as the head-mounted display system 1000 or patient interface 12000 may be less likely to wobble due to inertia during side movements. The parietal strap portion 1310 is an advantageous location for the counterweights 1386 as the counterweights 1386 are able to be spaced as far back as possible, allowing for less weight overall to achieve a particularA2578192 11.8 50counterbalancing moment to the head-mounted display system 1000 or patient interface 12000.

[0256] The positioning and stabilising structure 1300 may comprise a frontal strap portion 1394 constructed and arranged to engage the user’s head in use in a region overlying the frontal bone of the user’s head. Advantageously, the frontal strap portion 1394 and the parietal strap portion 1310 may be spaced apart in the anterior- posterior directions by a spacing less than the anterior-posterior length of the user’s head. This means that together they fit to and engage partially superior-facing surfaces of the user’s head, so as to support some, or most, of the weight of the headmounted display system 1000 or patient interface 12000. Other systems relying on a single strap engaging a posterior-facing surface of the user’s head may rely predominantly on the strap and display unit / patient interface 12000 “clamping” the user’s head, which may require greater forces on the user’s head and therefore may be uncomfortable and / or cause facial marking.

[0257] In the examples shown in Figs. 4A-4D, the positioning and stabilising structure 1300 comprises a band strap portion 1380 constructed and arranged to encircle the user’s head in use. The band strap portion 1380 may overlie the user’s forehead, and may form an occipital strap portion 1320 constructed and arranged to engage a region of the user’s head overlying or lying inferior to the occipital bone in use.

[0258] The band strap portion 1380 may be elastically extendable in length. For example, the band strap portion 1380 may be formed from an elastic material, such as an elastic textile material. In some examples, the band strap portion 1380 has an unextended length which is selectively adjustable by the user, for example by an adjustable buckle or an eyelet combined with a hook and loop fastening connection. The band strap portion 1380 may be selectively adjustable in length by the user and then, after adjustment, may also be elastically extendable in response to tension.

[0259] In some examples, the band strap portion 1380 comprises an occipital pad positioned in use to engage the region of the user’s head overlying or lying inferior to the occipital bone. The occipital pad may be formed by, as examples, an elastomericA2578192 11.8 51material (e.g. silicone or TPE), foam, and / or a textile material. In some examples, the occipital pad has a textile outer layer.

[0260] In the examples shown in Figs. 4A-4D, lateral portions of the band strap portion 1380 are held apart from each other by the parietal strap portion 1310 prior to donning of the head-mounted display system 1000 or patient interface 12000 by the user. The parietal strap portion 1310 and the arms 1210 to which it is attached may be rigidised and therefore hold a laterally spaced-out shape, which may in turn hold the lateral portions of the band strap portion 1380 apart from each other. This may provide for good usability as the band strap portion 1380 is held in an open configuration ready to fit over the user’s head. The band strap portion 1380 may pass between two layers of the parietal strap portion 1310 on each lateral side of the user’s head in use.

[0261] The frontal strap portion 1394 in some examples comprises a forehead pad 1395 configured to engage the user’s forehead, as shown in Figs. 4A-4D. In various examples, the forehead pad 1395 may formed from one or more of an elastomeric material (e.g. silicone, TPE or the like), foam and / or a textile material. The forehead pad 1395 may comprise an elastomeric user-contacting surface, which may advantageously provide for high friction between the forehead pad 1395 and the user’s forehead, to help support weight of the head-mounted display unit 1200 or patient interface 12000. In other examples, the forehead pad 1395 may comprise an inner foam portion, which may provide compliance and cushioning, and a textile outer layer, which may provide a comfortable feel on the user’s face and an aesthetically pleasing appearance.

[0262] In some examples, the forehead pad 1395 is provided to the band strap portion 1380, as shown in Figs. 4B-4D. In other examples the forehead pad 1395 is attached to the head-mounted display unit 1200 / patient interface 12000 and the band strap portion 1380 overlies the forehead pad 1395 or engages the user’s forehead superior to the forehead pad 1395. As shown in Fig. 4A, the band strap portion 1380 overlies the forehead pad 1395. Advantageously, this may help achieve good engagement between the forehead pad 1395 and the forehead.A2578192 11.8 52

[0263] In some examples, forehead pad 1395 comprises a frame and a cushion attached to the frame. The frame of the forehead pad 1395 may be attached to the head-mounted display unit 1200 / patient interface 12000. In such examples the forehead pad 1395 may support or suspend the display unit housing 1205 or flow generator casing 12200 anterior to the user’s face in use and the head -mounted display unit 1200 / flow generator casing 12200 may not engage the user’s face around a periphery of the user’s eye region, allowing the user to maintain some sight of their surroundings through peripheral vision. This configuration is shown in Fig. 4A. The forehead pad 1395 may form the interfacing structure 1100 in this configuration.

[0264] In other examples, such as those shown in Figs. 4B-4E, the head-mounted display system 1000 comprises an interfacing structure 1100 connected to the display unit housing and constructed and arranged to engage the user’s face in use around a periphery of the user’s eye region. In examples in which the positioning and stabilising structure 1300 is applied to a patient interface 12000, the patient interface 12000 comprises a user interface structure 12100. The interfacing structure 1100 or user interface structure 12100 may be constructed and arranged to engage sphenoid regions, cheek regions and the forehead region of the user’s face.

[0265] In the example shown in Fig. 4B, the head-mounted display system 1000 comprises a frontal connector 1345 constructed and arranged to connect between the frontal strap portion 1394 of the positioning and stabilising structure 1300 and each of the arms 1210 to support at least some weight of the head-mounted display unit 1200 in use via the arms 1210. The frontal connector 1345 may be particularly advantageous when the head -mounted display unit 1200 or patient interface 12000 does not otherwise have any dedicated means for connection to straps at a medial and superior location of the user’s forehead in use. The frontal connector 1345 may comprise a pair of lateral portions each extending towards and attaching to a respective one of the arms 1210. The frontal connector 1345 may be attached to a forwardmost portion of the each of the arms 1210. Advantageously, this may avoid the frontal connector 1345 urging the arms 1210 medially into uncomfortable contact with the user’s face, or at least reduce the severity of such an effect. The frontal connector 1345 may be Y-shaped, wishbone shaped or the like. The frontal connectorA2578192 11.8 531345, in any of its variations, may also be applied to a positioning and stabilising structure 1300 for patient interface 12000.

[0266] In the example shown in Fig. 4C, the positioning and stabilising structure 1300 comprises a top strap portion 1340 constructed and arranged to engage superior surfaces of the user’s head and connecting between the parietal strap portion 1310 and the frontal strap portion 1394 of the positioning and stabilising structure 1300 and / or the head-mounted display unit 1200 or patient interface 12000. In the example shown in Fig. 4C, the top strap portion 1340 is constructed and arranged to connect between the parietal strap portion 1310 and the band strap portion 1380. The top strap portion 1340 may be substantially aligned with the user’s mid-sagittal plane. The top strap portion 1340 may connect to the parietal strap portion 1310 and frontal strap portion 1394 or head-mounted display unit 1200 / patient interface 12000 by magnetic, buckle, hook and loop, or sewn connections, by way of examples only.

[0267] In some examples, the parietal strap portion 1310 is connected to the occipital strap portion 1320. As shown in Fig. 4D for example, the positioning and stabilising structure 1300 comprises a posterior support portion 1350 engaging the user’s head in the region overlying the parietal bones and in the region overlying or lying inferior to the occipital bone. In this example, the parietal strap portion 1310 partially forms the posterior support portion 1350. The posterior support portion 1350 may be connected to the occipital strap portion 1320. For example, the occipital strap portion 1320 may be connected to the posterior support portion 1350 by passing through one or more guides provided to the posterior support portion 1350. The posterior support portion 1350 may be annular in shape.

[0268] In various example, the posterior support portion 1350 may be formed from foam and / or textile materials. In some examples, the posterior support portion 1350 comprises an inner foam layer a textile outer layer. In some examples, the posterior support portion is thermoformed. The posterior support portion 1350 may be constructed to have a predetermined curved shape. As one example, the predetermined curved shape of the posterior support portion 1350 comprises curvature in two orthogonal directions. Advantageously, this may provide for good engagement with the user’s head and may provide for even distribution of force.A2578192 11.8 54

[0269] In some examples, such as is shown in Fig. 4D, the posterior support portion 1350 comprises a superior portion and an inferior portion separated by a hinge region 1314 on each side of the posterior support portion 1350, each hinge region constructed and arranged to encourage bending to occur at the hinge region (e.g. instead of elsewhere in the posterior support portion 1350). This controlled bending at the hinge region 1314 may advantageously facilitate good engagement of the posterior support portion 1350 with complex curvature of the user’s head. In some examples, the hinge region 1314 may be constructed to have greater extensibility than the superior portion and the inferior portion of the posterior support portion 1350.This may advantageously, allow the posterior support portion 1350 to accommodate a wide range of head shapes and sizes. The superior portion of the posterior support portion 1350 may at least partially form the parietal strap portion 1310 and the inferior portion of the posterior support portion 1350 may at least partially form the occipital strap portion 1320. The hinge regions 1314 may be formed by thermoforming, e.g. the hinge regions 1314 may be thermoformed details in the posterior support portion 1350. For example, the hinge regions 1314 may be formed thinner, by thermoforming, than the adjacent portions of the posterior support portion 1350, to provide greater flexibility at the hinge regions 1314. Alternatively, sewing may be used to create a seam along which the posterior support portion 1350 may tend to bend.

[0270] In some examples, one or more portions of the positioning and stabilising structure 1300 may house a cable, such as a power cable, earphone cable or the like. In some examples, the parietal strap portion 1310 comprises a cable routed therethrough. The cable may be routed between two layers of the parietal strap portion 1310. In other examples, the band strap portion 1380 comprises a cable routed therethrough. The cable may be routed between two layers of the band strap portion 1380.5.5.2.1 Rigidised occipital strap portion connected to arms

[0271] Fig. 4E shows a head-mounted display system 1000 according to a further example of the present technology. The head-mounted display system 1000 may comprise a head-mounted display unit 1200 comprising a display unit housing 1205, and may further comprise an interfacing structure 1100, all as described elsewhereA2578192 11.8 55herein. The head-mounted display system 1000 may further comprise a positioning and stabilising structure 1300 constructed and arranged to hold the head-mounted display unit 1200 in an operable position on the user’s head in use. In some examples of the present technology, the head-mounted display unit 1200 and interfacing structure 1100 in Fig. 4E are replaced by a patient interface 12000 comprising a user interface structure 12100 as described elsewhere herein. In such examples, the positioning and stabilising structure 1300 shown in Fig. 4E is constructed and arranged to hold the patient interface 12000 in an operable position on the user’s head in use.

[0272] The positioning and stabilising structure 1300 may comprise a pair of arms 1210 attached in use to the display unit housing 1205 on respective sides thereof. The arms 1210 may extend posteriorly from the display unit housing 1205. There are various similarities between the example shown in Fig. 4E and any of the examples shown in Figs. 4A-4D and Figs. 4F-4O. Not all of these similarities or shared features will be repeated in the description of the example shown in Fig. 4E. The features described with reference to one example are to be understood to be applicable to any other example, unless context requires otherwise.

[0273] In the example shown in Fig. 4E, the positioning and stabilising structure 1300 comprises a band strap portion 1380 constructed and arranged to encircle the user’s head in use. The band strap portion 1380 may be connected to each of the pair of arms 1210 in use. In this example, the band strap portion 1380 forms a frontal strap portion 1394 and an occipital strap portion 1320. The frontal strap portion 1394 may be constructed and arranged to engage the user’s head in use in a region overlying the frontal bone of the user’s head. The occipital strap portion 1320 may be configured to engage the user’s head at a region overlying or lying inferior to the occipital bone of the user’s head in use.

[0274] In the Fig. 4E example, the positioning and stabilising structure 1300 further comprises a pair of rigi disers 1323 provided to respective lateral sides of the occipital strap portion 1320. Each rigidiser 1323 may be fixedly connected to a respective one of the pair of arms 1210 in use. That is, the rigidisers 1323 may be unable to rotate with respect to the arms 1210. This may advantageously allow at leastA2578192 11.8 56some of the weight of the head-mounted display unit 1200 / patient interface 12000 to be transferred to and supported by the posterior of the user’s head.

[0275] As shown in Fig. 4E, each of the rigi disers 1323 curves inferiorly away from the respective arm 1210 in this example. Each of the rigidisers 1323 also comprises a posterior end. The rigidisers 1323 in this particular example do not connect to each other posterior to the user’s head. Each of the rigidisers 1323 may curve medially proximate the respective posterior end. This may advantageously assist in transferring some of the weight of the head-mounted display unit 1200 or patient interface 12000 to the posterior surfaces of the user’s head and may also advantageously, help resist riding up of the occipital strap portion 1320 in use, as the rigidisers 1323 curve medially into good engagement with partially inferior-facing surfaces of the posterior of the user’s head. The respective posterior ends of the rigidisers 1323 may be spaced apart in use. This may leave an unrigidised portion between the rigidisers 1323 which may help with donning the head-mounted display system 1000 / patient interface 12000 and / or allow for length adjustability of the occipital strap portion 1320.

[0276] Each rigi diser 1323 may be provided internally to the occipital strap portion 1320. In some examples, the occipital strap portion 1320 is formed at least partially from foam. The occipital strap portion 1320 may comprise one or more textile outer layers. In some examples the thickness of the occipital strap portion 1320, formed mostly by the thickness of the foam, may be 8mm.

[0277] The occipital strap portion 1320 may be adjustable in length. In the example shown in Fig. 4E, the occipital strap portion 1320 comprises a pair of anterior portions 1324 located on respective lateral sides of the user’s head in use and a posterior portion 1325 connecting the anterior portions 1324 of the occipital strap portion 1320. In this example, the posterior portion 1325 of the occipital strap portion 1320 comprises an unextended length that is selectively adjustable, for example by being connected to one or both of the anterior portions 1324 by buckles allowing for length adjustment of the posterior portion 1325. In this example, the posterior portion 1325 is elastically extendable, which may facilitate easy donning and doffing. In this example the anterior portions 1324 of the occipital strap portion 1320 may have a thickness of 8mm. The posterior portion 1325 of the occipital strap portion 1320 mayA2578192 11.8 57be thinner and / or more elastically extendable than the anterior portions 1324 and may have a thickness of 4mm.

[0278] In the example shown in Fig. 4E, the positioning and stabilising structure 1300 further comprises a parietal strap portion 1310 constructed and arranged to engage the user’s head in use in a region overlying the parietal bones of the user’s head. The parietal strap portion 1310 is connected to the band strap portion 1380 in this example.

[0279] In some examples, the parietal strap portion 1310 is formed at least partially from foam. The parietal strap portion 1310 may comprise one or more textile outer layers. In some examples the thickness of the parietal strap portion 1310, formed mostly by the thickness of the foam, may be 8mm.

[0280] The parietal strap portion 1310 may be adjustable in length. In the example shown in Fig. 4E, the parietal strap portion 1310 comprises a pair of anterior portions 1311 located on respective lateral sides of the user’s head in use and a posterior portion 1312 connecting the anterior portions 1311 of the parietal strap portion 1310. In this example, the posterior portion 1312 of the parietal strap portion 1310 comprises an unextended length that is selectively adjustable, for example by being connected to one or both of the anterior portions 1311 by buckles allowing for length adjustment of the posterior portion 1312. In this example, the posterior portion 1312 is elastically extendable, which may facilitate easy donning and doffing. In this example the anterior portions 1311 of the parietal strap portion 1310 may have a thickness of 8mm. The posterior portion 1312 of the parietal strap portion 1310 may be thinner and / or more elastically extendable than the anterior portions 1311 and may have a thickness of 4mm.

[0281] Length adjustment of the parietal strap portion 1310 and / or occipital strap portion 1320 may advantageously allow the positioning and stabilising structure 1300 to fit a wide range of head shapes and sizes well (e.g. comfortably and securely).

[0282] In some examples, the frontal strap portion 1394 of the positioning and stabilising structure 1300 is connected the head-mounted display unit 1200 or patient interface 12000 in use to support at least some weight of the head-mounted display unit 1200 / patient interface 12000. As shown in Fig. 4E the frontal strap portion 1394A2578192 11.8 58of the positioning and stabilising structure 1300 is connected to the head-mounted display unit 1200 by a frontal connector 1345. In this example the frontal connector 1345 comprises a strap portion connected directly to the head-mounted display unit 1200, for example to the display unit housing 1205. The frontal connector 1345 may alternatively comprise a strap portion connected directly to a flow generator casing 12200 of a patient interface 12000.

[0283] In other examples, the frontal connector 1345 may be constructed and arranged to connect between the frontal strap portion 1394 of the positioning and stabilising structure 1300 and each of the arms 1210 to support at least some weight of the head-mounted display unit 1205 / flow generator casing 12200 in use via the arms 1210. This type of frontal connector 1345 is described herein with reference to Fig. 4B.

[0284] In other examples, there may be no frontal connector 1345.

[0285] In the example shown in Fig. 4E, each anterior portion 1324 of the occipital strap portion 1320 is integrally formed with a respective one of the anterior portions 1311 of the parietal strap portion 1310. Also in this example, each anterior portion 1324 of the occipital strap portion 1320 is integrally formed with the frontal strap portion 1394. That is, in the Fig. 4E example, the frontal strap portion 1394, the anterior portions 1324 of the occipital strap portion 1320 and the anterior portions 1311 of the parietal strap portion 1310 are all integrally formed, for example cut from a foam and textile laminated sheet, with rigi disers 1323 inserted into the anterior portions 1324 of the occipital strap portion 1320. In other examples, any one or more of these portions may be formed separately from some or all of the other portions.5.5.1.3 Rigidised Lateral Portions

[0286] Figs. 4F-4N show a positioning and stabilising structure 1300 according to another example of the present technology and Fig. 40 shows a patient interface 12000 comprising the positioning and stabilising structure 1300 shown in Figs. 4F- 4N. The patient interface 12000 shown in Fig. 40, like other patient interfaces 12000 described or referred to herein, may comprise a respiratory pressure therapy (RPT) device including an electric blower configured to generate pressurized breathable air. The patient interface 12000 may further comprise a seal-forming structure configuredA2578192 11.8 59to form a seal against the patient’s face and deliver a flow of breathable air to an entrance to the patient’s airways. The seal-forming structure may at least partially define a plenum chamber configured to receive the pressurized air. The seal-forming structure may be formed by the user interface structure 12100 or a therapy cushion component 12500 thereof, as described in more detail elsewhere herein. The patient interface 12000 may further comprise a flow generator casing 12200 that at least partly encloses the electric blower and is connected to the plenum chamber, the casing including at least one air opening to receive ambient air for delivery to the RPT device. The positioning and stabilising structure 1300 may be configured to maintain the seal -forming structure and the blower / flow generator casing 12200 in a therapeutically effective position. All patient interfaces 12000 referenced herein are to be understood to comprise any one or more of the above features.

[0287] The positioning and stabilising structure 1300 shown in Figs. 4F-4N does not comprise a frontal connector 1345. That is, the positioning and stabilising structure 1300 may support the patient interface 12000 solely via arms 1210 extending posteriorly from the patient interface 12000 or flow generator casing 12200 thereof. For example, the positioning and stabilising structure 1300 may be constructed and arranged to hold the patient interface 12000 in an operable position on the user’s head in use.

[0288] The positioning and stabilising structure 1300 may comprise a pair of lateral portions 1301 each constructed and arranged to be positioned on a respective lateral side of the user’s head in use. In this example, each lateral portion 1301 comprises a respective one of a pair of arm connection portions 1335 each configured to be connected to a respective one of a pair of arms 1210 extending posteriorly from the patient interface 12000 (or flow generator casing 12200 thereof in the example illustrated in Fig. 40) on respective sides of the user’s head. For example, the arm connection portions 1335 may be constructed and arranged to form snap fit connections with the arms 1210 extending from the flow generator casing 12200. That said, any suitable manner of connection is to be understood to be applicable. The arm connection portions 1335 as shown in Figs. 4F-4O comprise an opening which is configured to connect to the arms 1210 of the patient interface 12000. The opening may receive a clip portion attachable to the arms 1210. Different clip portions may beA2578192 11.8 60installed in the openings of the arm connection portions 1335 to allow for connection to different patient interfaces 12000. The openings forming the arm connection portions 1335 in this example are square, which may help resist rotation of the components received in the opening. As will be described, the lateral portions 1301 may advantageously be configured to fixedly connect with arms 1210 of a patient interface 12000 so as to prevent rotation of the arms 1210 with respect to the lateral portions 1301. This may advantageously facilitate the positioning and stabilising structure 1300 to support the weight of the patient interface 12000 solely via the arms 1205 without a strap connection to the top of the patient interface 12000 and, in some forms of the technology, without engagement of the flow generator casing 12200 against the user’s face other than by a seal -forming structure (e.g. other than a portion of a therapy cushion component). In other examples, the openings in the armconnection portions 1335 may be other non-circular shapes (hexagon, squircle, oval, rectangle) or may be circular but may include a feature (e.g. a keyed connection) to prevent rotation of the arms 1210 or the component within the opening that the arms 1210 connect to.

[0289] In some examples, the arms 1210 are connected to the patient interface 12000 or flow generator casing 12200 thereof without the ability to rotate with respect thereto. In such examples this may enable the positioning and stabilising structure 1300 to support more weight of the patient interface 12000 via the arms 1210. In other examples, the arms 1210 are rotatably / pivotably connected to the patient interface 12000 or flow generator casing 12200 thereof. In such examples this may allow the user greater freedom to adjust the fit of the patient interface 12000 since the arms 1210 allow for additional movement and rotation of the patient interface 12000 or flow generator casing 12200 thereof with respect to the positioning and stabilising structure 1300. For example, this may allow the user to adjust the patient interface 12000 or flow generator casing 12200 thereof to bias it towards the forehead or cheeks, as may be desired by the user. In some examples, the flow generator casing 12200 may be rotatable with respect to the arms 1210 between a series of indexed rotational positions, which may advantageously enable the flow generator casing 12200 to be rotatable by user but held in place in the desired position in use.A2578192 11.8 61

[0290] In some examples, the arms 1210 may be extendable in length to allow the user to adjust the spacing between the flow generator casing 12200 and the positioning and stabilising structure 1300. When the user is lying on their back, looking upwards with the posterior side of their head against a pillow or other horizontal surface, the positioning and stabilising structure 1300 may support some or all of the weight of the patient interface 12000. In such a position, the user may adjust the patient interface 12000, for example by adjusting the length of the arms 1300, to cause the patient interface 12000 or flow generator casing 12200 thereof to translate away from the positioning and stabilising structure 1300. This may increase the amount of weight of the patient interface 12000 supported by the positioning and stabilising structure 1300 and reduce the amount of weight bearing on the user’s face. Any suitable mechanism to provide length adjustment to the arms 1210 or to provide for translation adjustment of the flow generator casing 12200 with respect to the arms 1210 may be employed, such as lockable telescoping arms or a rack and pinion connection between arms 1210 and flow generator casing 12200 with a dial-type adjuster, as examples only.

[0291] With reference to Fig. 4F and 40 in particular, the positioning and stabilising structure 1300 may comprise multiple portions configured to engage the user’s head in different regions. The positioning and stabilising structure 1300 may comprise a frontal strap portion 1394 formed at least partially by the lateral portions 1301, the frontal strap portion 1394 being constructed and arranged to engage the user’s head in use in a region overlying the frontal bone of the user’s head. The positioning and stabilising structure 1300 may comprise a parietal strap portion 1320 formed at least partially by the lateral portions 1301, the parietal strap portion 1320 being constructed and arranged to engage the user’s head at a region overlying the parietal bones of the user’s head in use. Additionally, the positioning and stabilising structure 1300 may comprise an occipital strap portion 1320 formed at least partially by the lateral portions 1301, the occipital strap portion 1320 constructed and arranged to engage the user’s head at a region overlying or lying inferior to the occipital bone of the user’s head in use.

[0292] Each lateral portion 1301 may further comprise a rigidised portion 1309 (identified in Fig. 4J, having a shape similar to the shape of the rigidiser 1305, whichA2578192 11.8 62will be described). The rigidised portion 1309 may be stiffer than one or more adjacent portions. In some examples the rigidised portion 1309 is rigidised by a rigidiser provided to or within the lateral portion 1301. Figs. 4J and 4K, which show a lateral portion 1301 and a rigidiser 1305, respectively. In this example, the rigidiser 1305 is within the lateral portion 1301, as will be described in more detail. The rigidiser 1305 may be a component that at least partially rigidises the lateral portion 1301 and the ridigised portion 1309 of the lateral portion 1301 may be the portion of the lateral portion 1301 that is rigidised and which may be rigidised at least partially by the rigidiser 1305.

[0293] With reference to Figs. 4J and 4K, each rigidised portion 1309 of the lateral portion 1301 in this example comprises a first portion 1305a located within the frontal strap portion 1394, a second portion 1305b located within the parietal strap portion 1310 and a third portion 1305c located within the occipital strap portion 1320. The rigidised portion 1309 may be partially within each of the frontal strap portion 1394, parietal strap portion 1310 and occipital strap portion 1320. The rigidised portion 1309 may advantageously hold the shape of the positioning and stabilising structure 1300 and may advantageously position each of the frontal strap portion 1394, parietal strap portion 1310 and occipital strap portion 1320 in the correct general location on the user’s head in use during donning of the patient interface 12000.

[0294] In some examples of the present technology, the lateral portions 1301 are able to conform to the shape of the user’s head. Advantageously, this allows the lateral portions 1301 to fit snugly, securely and comfortably to the user’s head in use, despite a portion of each lateral portion 1301 being rigidised. In each rigidised portion 1309, the first portion 1305a, the second portion 1305b and the third portion 1305c of said rigidised portion 1309 are all able to flex with respect to each other. For example, each of the first portion 1305a, the second portion 1305b and the third portion 1305c are able to flex independently of the others. Advantageously, this facilitates the lateral portion 1301 conforming to the user’s head and having the ability to flex to fit to a wide range of head shapes and sizes. The three portions of the rigidised portion 1309 are able to flex medially to engage the user’s head and substantially match the user’s head curvature. In each lateral portion 1301, the respective rigidised portion 1309 mayA2578192 11.8 63extend from proximate the respective arm connection portion 1335 into each of the frontal strap portion 1394, the parietal strap portion 1310 and the occipital strap portion 1320. This arrangement may advantageously provide for force transfer from the arm connection portion 1335 to all of the frontal strap portion 1394, parietal strap portion 1310 and occipital strap portion 1320.

[0295] With reference to Figs. 4J, 4K and 40, each rigisider 1305 may comprise a central portion 1307 substantially central with respect to the shape of the rigidiser 1305. The central portion 1307 may be located superior to and substantially aligned with the user’s ear in use. Each rigidiser 1305 may comprise a portion extending from the central portion 1307 in an anterosuperior direction in use. This portion may extend into the frontal strap portion 1394 in use and may partially form the first portion 1305a of the rigidised portion 1309 of the lateral portion 1301. Additionally or alternatively, each rigidiser 1305 may comprise a portion extending from the central portion 1307 in a posterosuperior direction in use. This portion may extend into the parietal strap portion 1310 in use and may partially form the second portion 1305b of the rigidised portion 1309 of the lateral portion 1301. Additionally or alternatively, each rigidiser 1305 may comprise a portion extending from the central portion 1307 in a posteroinferior direction in use. This portion may extend into the occipital strap portion 1320 in use and may partially form the third portion 1305c of the rigidised portion 1309 of the lateral portion 1301.

[0296] Each arm connection portion 1335 may be constructed and arranged to fixedly connect to the respective one of the pair of arms 1210 extending posteriorly from the display unit housing 1205 substantially without permitting rotation of the respective arm with respect to the arm connection portion 1335. This may advantageously facilitate the arm connection portion 1335 to resist moments applied by the arm 1210 to support the weight of the head-mounted display unit 1200 or patient interface 12000. In particular, the arm connection portions 1335 are constructed and arranged to fixedly connect to respective arms 1210 of the pair of arms 1210 extending posteriorly from the display unit housing 1205 substantially without permitting rotation of the respective arms 1210 with respect to the rigidised portions 1309. In some forms of the present technology, the positioning and stabilising structure 1300 is able to support substantially the entire weight of theA2578192 11.8 64patient interface 12000 via the arm connection portions 1335. This may advantageously facilitate the patient interface 12000 to be supported in an in-use position without the need to be in contact with the user’s face, other than by a sealforming structure such as therapy cushion component 12500, in some examples.

[0297] Some prior art systems having head-mounted displays may rely on headgear straps pulling the device having the display against the user’s face (e.g. in a posterior direction) to hold it in position. That is, the headgear and display device may “clamp” the user’s head to remain in place. This may be uncomfortable for the user, especially for a long period of use. The positioning and stabilising structure 1300 and patient interface 12000 of the present technology may advantageously support the weight of the patient interface 12000 via the arms 1210 and strap portions of the positioning and stabilising structure 1300 such that the patient interface 12000 does not need to be pulled hard against the user’s face any more so than may be required to maintain a seal by the seal -forming structure around an entrance to the user’s airways. This may provide for a highly stable and yet comfortable patient interface 12000. Additionally, while the positioning and stabilising structure 1300 provides for stable and comfortably support of the patient interface 12000 during sleeping in bed, it may also be particular advantageous for supporting the patient interface 12000 during use on an airplane, either when the patient is awake or is asleep. The rigidised positioning and stabilising structure 1300 and its ability to support much of the weight of the patient interface 12000 without requiring “clamping” against the patient’s face may be particularly advantageous when during airplane use, when the patient is in a sitting position rather than lying down.5.5.2.3.1 Layers of the lateral portions

[0298] In some examples of the present technology, each lateral portion 1301 is at least partially formed in a layered construction. Figs. 4G and 4H illustrate the layered construction in one example. The layered construction in this example comprises a user-facing layer 1302 facing the user’s head in use. In this example, a rigidiser 1305 is provided on the opposite side of the user-facing layer 1302 to the user’s head in use. In this example the rigidiser 1305 at least partially forms the rigidised portion 1309 of the lateral portion 1301 to which it is provided. The rigidiser 1305 is constructed and arranged to stiffen the respective lateral portion 1301 withinA2578192 11.8 65the rigidised portion 1309. In use, much or all of the user-facing layer 1302 will engage and contact the user’s head. The user-facing layer 1302 may comprise a textile material forming a user-facing surface (e.g. an inward / medially facing surface). In some examples, the user-facing layer 1302 comprises a laminate comprising a foam layer and the textile material. This may provide for a comfortable feeling and aesthetically pleasing positioning and stabilising structure 1300. In some examples, the foam layer is formed from PU foam, but may also be formed from any other suitable foam. The textile material may be Nylon or a combination of Nylon and elastane, or may be formed from any other suitable textile material(s) such as polyester or polypropylene, by way of example only.

[0299] The ridigiser 1305 may be formed from a polymer material and may for example be formed by injection moulding. For example, the rigidser 1305 may be formed from Nylon or PCABS. In some examples the rigidisers 1305 are formed from a thermoplastic material. In some examples the rigidisers 1305 may be formed from a thermoplastic elastomer, such as Hytrel, by way of example only. In the illustrated example, the rigidiser 1305 is formed (e.g. moulded) in a non-planar shape and imparts a three-dimensional curved shape to the respective lateral portion 1301. The three-dimensional curved shape imparted to the lateral portions 1301 may approximate the curvature of a head surface that each lateral portion 1301 engages in use. This may reduce the amount of deformation required in each lateral portion 1301 during fitting, which may provide for a comfortable fit. However, the rigidiser 1305 is able to flex away from the non-planar shape in use to conform to the shape of the user’s head. This may provide for a comfortable fit across a wide range of users.

[0300] In the example shown in Figs. 4F-4O, each rigidiser 1305 is constructed and arranged to resist bending towards directions parallel to the sagittal plane of the user’s head (e.g. superior, inferior, anterior and posterior) in use more so than towards directions normal to the sagittal plane of the user’s head (e.g. medial and lateral) in use. As shown in Fig. 41 for example, the rigidiser 1305 is thin in comparison to its width and height. Each of the portions of the rigidiser 1305 corresponding to each of the first portion 1305a, the second portion 1305b and the third portion 1305c of the rigidised portion 1309 are therefore readily able to bend towards medial and lateral directions due to the thin cross section providing little resistance to bending towardsA2578192 11.8 66these directions. The other dimension of the cross section of each rigidiser 1305, which may be considered a width or height dimension and which resists bending towards the superior, inferior, anterior or posterior directions in use, is much larger than the thickness and therefore provides much more resistance to bending. The result is a rigidiser 1305 that is readily able to conform to the shape of user’s head in use to lock the positioning and stabilising structure 1300 in place on the user’s head, while also supporting weight of the patient interface 12000 due to resistance to bending towards directions parallel to the sagittal plane of the user’s head in use.

[0301] As shown in Figs. 4H and 41, the layered construction comprises a nonuser facing layer 1303 on an opposite side of the rigidiser 1305 to the user-facing layer 1302. The non-user facing layer 1303 may face away from the user’s head in use. The non-user facing layer 1303 may comprise a textile material forming a nonuser facing surface (e.g. an outward / laterally facing surface). In some examples, the non-user facing layer 1303 comprises a laminate comprising a foam layer and the textile material. This may provide for a comfortable feeling and aesthetically pleasing positioning and stabilising structure 1300. In some examples, the foam layer is formed from PU foam or any other suitable foam. The textile material may be Nylon, a combination of Nylon and elastane, or any other suitable textile material. The non- user facing layer 1303 may be formed from the same material as the user-facing layer 1302. In some examples the non-user facing layer 1303 may be formed from a different material to the user-facing layer 1302.

[0302] In the illustrated example, regions of the lateral portion 1301 not occupied by the rigidiser 1305 are formed at least partially by the user-facing layer 1302 and the non-user facing layer 1303. In the illustrated example, because the user-facing layer 1302 and non-user facing layer 1303 comprise foam layers, the user is unable to feel, or unlikely to notice or be bothered by, the edges of the rigidiser 1305 in use. In other examples, the user-facing layer 1302 and non-user facing layer 1303 comprise a gel, a spacer fabric, an elastomer or other cushioning material.

[0303] As shown in Figs. 4G-4J, the layered construction comprises at least one stiffening layer 1304 proximate the arm connection portion 1335. In this example the stiffening layer 1304 surrounds the arm connection portion 1335. This may advantageously stiffen the arm connection portion 1335, facilitating resistance againstA2578192 11.8 67movement of the arms 1210 in use with respect to the positioning and stabilising structure 1300. The arm connection portion 1335 may overlap with the rigidiser 1305 (shown in Fig. 4H). Advantageously, this may facilitate transfer of forces to the rigidised portion 1309, facilitating the positioning and stabilising structure 1300 as a whole to resist rotation or other movement of the arms 1210. In the illustrated example, as shown in Fig. 4H, the layered construction may comprise two stiffening layers 1304. The two stiffening layers 1304 overlap with the rigidiser 1305 with a portion of the rigidiser 1305 being between the two stiffening layers. In this example, each stiffening layer 1304 may comprise a stiffening mesh. In other examples, any suitable stiffening structure may be applied, such as a thick film or moulded rigidiser, as examples only.

[0304] In the example shown in Figs. 4F-4O, each rigidiser 1305 comprises a recessed portion 1306 (see Fig. 4K). The recessed portion 1306 may reduce the width and / or height of the rigidiser 1305 proximate the arm connection portion 1335, for example to provide space for the opening in the illustrated example. In other examples of the present technology, the rigidiser 1305 in each lateral portion 1301 may surround the arm connection portion 1335. In further examples, the rigidiser 1305 may define the arm connection portion 1335 or an opening forming the arm connection portion 1335. In such examples the rigidiser 1305 may comprise an opening at least partially defining the arm connection portion 1335. In some examples the arms 1210 may connect directly to the rigidiser 1305.

[0305] In some examples, the positioning and stabilising structure 1300 may be constructed to guide a cable connected to the patient interface 12000 or flow generator casing 12200 thereof, such as a power cable or signal cable, along a predetermined path, such as along the occipital strap portion 1320. The occipital strap portion 1320 may comprise a guide configured to receive the cable and direct it in a posteroinferior direction along the occipital strap portion 1320. The guide may be a clip, a loop of material, a sleeve or other component constructed to receive or attach to a cable so as to hold the cable in place.5.5.2.3.2 Adjustable strap portions

[0306] One or more of the strap portions of the positioning and stabilising structure 1300 may be adjustable in length.A2578192 11.8 68

[0307] In some examples, the frontal strap portion 1394 is adjustable in length. Figs. 4L and 4M show the two lateral portions 1301 separately. In the example shown in Figs. 4F, 4L and 4M, the frontal strap portion 1394 comprises a first portion 1394a extending from one of the lateral portions 1301, the first portion 1394a passing through an opening 1394b provided to the other of the lateral portions 1301 and being secured back to itself.

[0308] In some examples, the parietal strap portion 1310 is adjustable in length. In the illustrated example, the parietal strap portion 1310 comprises a first portion 1310a extending from one of the lateral portions 1301, the first portion 1310a passing through an opening 1310b provided to the other of the lateral portions 1301 and being secured back to itself.

[0309] In some examples, the occipital strap portion 1320 is adjustable in length. In the illustrated example, the occipital strap portion 1320 comprises a first portion 1320a extending from one of the lateral portions 1301, the first portion 1320a passing through an opening 1320b provided to the other of the lateral portions 1301 and being secured back to itself.

[0310] The lateral portion 1301 shown in Fig. 4L has eyelets forming openings (e.g. 1394b, 1310b, 1320b) to receive strap portions (1394a, 1310a, 1320a) attached to the lateral portion 1301 shown in Fig. 4M. The eyelets may be formed from stainless steel, a polymer material or any other suitable material. Each of the first portions 1394a, 1310a and / or 1320a may be constructed to form a hook-and-loop connection with itself, respectively. The end of each first portion 1394a, 1310a and / or 1320a may comprise a portion having a hook material configured to attach to a non-user facing layer of itself formed from a loop material (e.g. a textile material).

[0311] In other examples, any one or more of the frontal strap portion 1394, parietal strap portion 1310 and occipital strap portion 1320 may comprise domes, magnets, a sliding buckle, a ladderlock buckle, a dial adjustment mechanism or any other suitable adjustment feature providing for selective adjustment of the effective length of the strap portion. In further examples any one or more of the frontal strap portion 1394, parietal strap portion 1310 and occipital strap portion 1320 may not be selectively adjustable in length and may instead be elastically extendable toA2578192 11.8 69automatically adjust in length to fit the user’s head. Further still, in other examples any one or more of the frontal strap portion 1394, parietal strap portion 1310 and occipital strap portion 1320 may not be adjustable in length.

[0312] Advantageously, the ability for all of the frontal strap portion 1394, parietal strap portion 1310 and occipital strap portion 1320 to be adjusted enables the positioning and stabilising structure 1300 to fit snugly and securely to a wide range of user head shapes and sizes. Furthermore, the positioning and stabilising structure1300 being securely but comfortably locked to the shape of the user’s head may advantageously facilitate the positioning and stabilising structure 1300 to resist rotation of the arms 1210, thereby supporting much, or all, of the weight of the patient interface 12000 in use. This may advantageously reduce the amount of force with which the patient interface 12000 needs to be pulled against the user’s face, to achieve stability in use.

[0313] Another aspect of some forms of the present technology is that, one or more of the frontal strap portion 1394, parietal strap portion 1310 and occipital strap portion 1320 may comprise rigidised lateral portions separated by a non-rigidised medial portion. The positioning and stabilising structure 1300 shown in Figs. 4F-4O embodies this aspect. Each of the frontal strap portion 1394, parietal strap portion 1310 and occipital strap portion 1320 is formed at its lateral ends by a respective one of the rigidised portions 1309 of the lateral portions 1301 and is formed between its lateral ends by non-rigidised strap portion (e.g. the first portions 1394a, 1310a and 1320a, which are not rigidised). The lack of rigid connection within the positioning and stabilising structure 1300 of one lateral portion 1301 to the other lateral portion1301 means that the lateral portions 1301 are able to move medially and laterally with respect to each other to adjust to the width of the user’s head (the arms 1210 attached to the patient interface 12000 may also move or flex medially / laterally as required). Then, the three limbs of the rigidised portions 1309 (e.g. the portions of each rigidised portion 1309 that form the frontal strap portion 1394, parietal strap portion 1310 and occipital strap portion 1320) are able to flex independently to fit well to the local curvature of the user’s head at or proximate the frontal, parietal and occipital bones. In other examples, one or more of the frontal strap portion 1394, parietal strap portionA2578192 11.8 701310 and occipital strap portion 1320 may be rigidised along its full length from one lateral portion 1301 to the other lateral portion 1301.5.5.2.3.3 Counterweights

[0314] Fig. 4N shows the positioning and stabilising structure 1300 of Figs. 4F- 4M with a variation according to another aspect of the present technology. In this example the parietal strap portion 1310 is constructed and arranged to support one or more counterweights 1386.

[0315] As illustrated, the parietal strap portion 1310 is constructed and arranged to support a pair of counterweights 1386, each spaced from and located on opposing sides of the mid-sagittal plane of the user’s head in use. The lateral portions 1301 may be constructed and arranged to support the pair of counterweights 1386 in the parietal strap portion 1310. The counterweights 1386 may be provided to the portion of the lateral portion 1301 that forms part of the parietal strap portion 1310. The one or more counterweights 1386 may be configured to removably attach to the parietal strap portion 1310, such as with a hook-and-loop connection. For example, each counterweight 1386 may be provided with hook material configured to form a hook- and-loop connection with the loop material forming the non-user facing layer 1303 of the lateral portion 1301.

[0316] Also as illustrated in Fig. 4N, the occipital strap portion 1320 is constructed and arranged to support a pair of counterweights 1386, each spaced from and located on opposing sides of the mid-sagittal plane of the user’s head in use. The lateral portions 1301 may be constructed and arranged to support the pair of counterweights 1386 in the occipital strap portion 1320. The counterweights 1386 may be provided to the portion of the lateral portion 1301 that forms part of the occipital strap portion 1320. The one or more counterweights 1386 may be configured to attach to the occipital strap portion 1320 with a hook-and-loop connection. For example, each counterweight 1386 may be provided with hook material configured to form a hook-and-loop connection with the loop material forming the non-user facing layer 1303 of the lateral portion 1301.

[0317] The counterweights 1386 may advantageously counter some of the weight of the patient interface 12000 transferred to the positioning and stabilising structureA2578192 11.8 711300 via the arms 1210. The counterweights 1386 may advantageously shift the overall centre of mass of the patient interface 12000 posteriorly, closer to the user’s neck or centre of the head (e.g. mid-coronal plane), which may reduce or prevent the weight of the patient interface 12000 from pulling the user’s head anteriorly and inferiorly. The counterweights 1386 are provided in pairs on each of the parietal strap portion 1310 and occipital strap portion 1320, which may provide for more stability than a single but twice as heavy counterweight 1386 provided at the posterior-most point of each strap portion (e.g. in the mid-sagittal plane). Counterweights 1386 are advantageously provided to both the parietal strap portion 1310 and occipital strap portion 1320 to allow the overall weight of the counterweights to be adjusted but removing the two counterweights 1386 on one of the parietal strap portion 1310 or occipital strap portion 1320, or removing all, depending on preference, neck strength and / or to vary cheek or forehead pressure (moving counterweights from one of the parietal strap portion 1310 and the occipital strap portion 1320 to the other may allow the user to switch between more cheek pressure or more forehead pressure, when the patient interface 12000 engages the users cheeks and forehead). Additionally, four smaller counterweights 1386 rather than one large counterweight allows the weight to be well spread out on the back of the user’s head.

[0318] The counterweights 1386 being removeable also advantageously allow for counterweights 1386 to be added or removed depending on how the patient interface 12000 is being used. For examples, counterweights 1386 may be attached for use while sitting, for example during airplane use, and may be removed for sleeping while lying down.

[0319] The counterweights 1386 may be formed from any suitable heavy material and may be overmoulded with a soft material, e.g. an elastomer. For a patient interface 12000 with a weight of about 600g, counterweights 1386 having a total weight of approximately 100-150g may be appropriate to shift the centre of mass of the patient interface 12000 sufficiently posteriorly for better comfort. However, the ideal total weight of the counterweights 1386 depends on patient preference. Advantageously, the removable counterweights 1386 allows for the number of counterweights 1386 and the weight of each counterweight 1386 to be customised by the patient.A2578192 11.8 725.6 GLOSSARY

[0320] 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.5.6.1 General

[0321] 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.

[0322] 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.

[0323] Continuous Positive Airway Pressure (CPAP) therapy. Respiratory pressure therapy in which the treatment pressure is approximately constant through a respiratory cycle of a patient. In some forms, the pressure at the entrance to the airways will be slightly higher during exhalation, and slightly lower during inhalation. In some forms, the pressure will vary between different respiratory cycles of the patient, for example, being increased in response to detection of indications of partial upper airway obstruction, and decreased in the absence of indications of partial upper airway obstruction.

[0324] Patient'. A person, whether or not they are suffering from a respiratory condition.

[0325] Pressure: Force per unit area. Pressure may be expressed in a range of units, including cmFFO, g-f / cm2and hectopascal. 1 cmFFO is equal to 1 g-f / cm2and is approximately 0.98 hectopascal (1 hectopascal = 100 Pa = 100 N / m2= 1 millibar ~ 0.001 atm). In this specification, unless otherwise stated, pressure is given in units of cmFLO.

[0326] 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.5.6.1.1 Materials & their properties

[0327] (Durometer Hardness (Indentation Hardness) '. A material property measured by indentation of an indentor (e.g. As measured in accordance with ASTM D2240).A2578192 11.8 73• ‘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, steel or aluminium, and may not e.g. readily deform under finger pressure.

[0328] Silicone or Silicone Elastomer'. A synthetic rubber. In this specification, a reference to silicone is a reference to liquid silicone rubber (LSR) or a compression moulded silicone rubber (CMSR). One form of commercially available LSR is SILASTIC (included in the range of products sold under this trademark), manufactured by Dow Corning. Another manufacturer of LSR is Wacker. Unless otherwise specified to the contrary, an exemplary form of LSR has a Shore A (or Type A) indentation hardness in the range of about 35 to about 45.

[0329] Polycarbonate', a thermoplastic polymer of Bisphenol-A Carbonate.5.6.1.2 Mechanics

[0330] Axes: a. Neutral axis'. An axis in the cross-section of a beam or plate along which there are no longitudinal stresses or strains.

[0331] Deformation'. The process where the original geometry of a member (structure or component) 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.

[0332] Stiffness'. The ability of a structure or component to resist deformation in response to an applied load. A structure or component may have an axial stiffness, a bending stiffness, and a torsional stiffness. A structure or component is said to be stiff when it does not deform easily when subject to mechanical forces. Stiffness of a structure or component is related to its material properties and its shape. The inverse of stiffness is flexibility.

[0333] Elasticity. The ability of a material to return to its original geometry after deformation.

[0334] Viscous'. The ability of a material to resist flow.

[0335] Yield. The situation when a material can no longer return back to its original geometry after deformation.5.6.1.3 Structural Elements

[0336] Thin structures:A2578192 11.8 74a. Beams, b. Membranes, Plates & Shells

[0337] Thick structures: Solids

[0338] 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.

[0339] 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.

[0340] Load transfer member: A structural member which transfers load from one location to another.

[0341] Load support member: A structural member which transfers load from one location to a non- structural item, such as the face.

[0342] Tension member: A structural element that is subjected to tensional forces.

[0343] Tie (noun)'. A structure designed to resist tension.

[0344] Compression member: A structural element that is subjected to compression forces.

[0345] 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.

[0346] 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.

[0347] Frame'. Frame will be taken to mean a mask structure that bears the load of tension between two or more points of connection with a headgear. A mask frame may be a non-airtight load bearing structure in the mask. However, some forms of mask frame may also be air-tight.

[0348] 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.A2578192 11.8 755.6.2 Anatomy5.6.2.1 Anatomy of the face

[0349] Frankfort horizontal plane'. A line extending from the most inferior point of the orbital margin to the left tragion. The tragi on is the deepest point in the notch superior to the tragus of the auricle.

[0350] Otobasion inferior '. The lowest point of attachment of the auricle to the skin of the face.

[0351] Otobasion superior'. The highest point of attachment of the auricle to the skin of the face.

[0352] 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.5.6.2.1 Anatomy of the skull

[0353] Frontal bone'. The frontal bone includes a large vertical portion, the squama frontalis, corresponding to the region known as the forehead.

[0354] 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.

[0355] Parietal bones'. The parietal bones are the bones that, when joined together, form the roof and sides of the cranium.

[0356] 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.

[0357] Zygomatic bones'. The face includes two zygomatic bones, located in the upper and lateral parts of the face and forming the prominence of the cheek.

[0358] 5.6.3 Patient interface

[0359] 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.

[0360] Headgear : Headgear will be taken to mean a form of positioning and stabilizing structure designed to hold a device, e.g. a mask, on a head.A2578192 11.8 76

[0361] 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.

[0362] 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.5.7 OTHER REMARKS

[0363] 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.

[0364] Unless the context clearly dictates otherwise and where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit, between the upper and lower limit of that range, and any other stated or intervening value in that stated range is encompassed within the technology. The upper and lower limits of these intervening ranges, which may be independently included in the intervening ranges, are also encompassed within the technology, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the technology.

[0365] Furthermore, where a value or values are stated herein as being implemented as part of the technology, it is understood that such values may be approximated, unless otherwise stated, and such values may be utilized to any suitable significant digit to the extent that a practical technical implementation may permit or require it.

[0366] Furthermore, “approximately”, “substantially”, “about”, or any similar term used herein means + / - 5-10% of the recited value.

[0367] 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 orA2578192 11.8 77equivalent 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.

[0368] 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.

[0369] 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.

[0370] 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.

[0371] 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.

[0372] The subject headings used in the detailed description are included only for the ease of reference of the reader and should not be used to limit the subject matter found throughout the disclosure or the claims. The subject headings should not be used in construing the scope of the claims or the claim limitations.

[0373] 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 stepsA2578192 11.8 78in the methodologies may be described or illustrated in an order, such an ordering is not required. Those skilled in the art will recognize that such ordering may be modified and / or aspects thereof may be conducted concurrently or even synchronously.

[0374] It is therefore to be understood that numerous modifications may be made to the illustrative examples and that other arrangements may be devised without departing from the spirit and scope of the technology.A2578192 11.8 79

Claims

6 CLAIMS1. A positioning and stabilising structure for a patient interface, the positioning and stabilising structure constructed and arranged to hold the patient interface in an operable position on the user’s head in use, the positioning and stabilising structure comprising: a pair of lateral portions each constructed and arranged to be positioned on a respective lateral side of the user’s head in use, wherein: each lateral portion comprises a respective one of a pair of arm connection portions each configured to be connected to a respective one of a pair of arms extending posteriorly from the patient interface on respective sides of the user’s head; and each lateral portion comprises a rigidised portion being stiffer than one or more adjacent portions; a frontal strap portion formed at least partially by the lateral portions, the frontal strap portion being constructed and arranged to engage the user’s head in use in a region overlying the frontal bone of the user’s head; a parietal strap portion formed at least partially by the lateral portions, the parietal strap portion constructed and arranged to engage the user’s head at a region overlying the parietal bones of the user’s head in use; an occipital strap portion formed at least partially by the lateral portions, the occipital strap portion constructed and arranged to engage the user’s head at a region overlying or lying inferior to the occipital bone of the user’s head in use; wherein each rigidised portion comprises a first portion located within the frontal strap portion, a second portion located within the parietal strap portion and a third portion located within the occipital strap portion.

2. The positioning and stabilising structure of claim 1, wherein the lateral portions are able to conform to the shape of the user’s head.A2578192 11.8 803. The positioning and stabilising structure of claim 1 or claim 2, wherein in each rigidised portion, the first portion, the second portion and the third portion of said rigidised portion are all able to flex with respect to each other.

4. The positioning and stabilising structure of any one of claims 1-3, wherein in each lateral portion, the respective rigidised portion extends from proximate the respective arm connection portion into each of the frontal strap portion, the parietal strap portion and the occipital strap portion.

5. The positioning and stabilising structure of any one of claims 1-4, wherein each arm connection portion is constructed and arranged to fixedly connect to the respective one of the pair of arms extending posteriorly from the patient interface substantially without permitting rotation of the respective arm with respect to the arm connection portion.

6. The positioning and stabilising structure of any one of claims 1-4, wherein the arm connection portions are constructed and arranged to fixedly connect to respective arms of the pair of arms extending posteriorly from the patient interface substantially without permitting rotation of the respective arms with respect to the rigidised portions.

7. The positioning and stabilising structure of any one of claims 1-6, wherein in use, the positioning and stabilising structure is able to support substantially the entire weight of the patient interface via the arm connection portions,8. The positioning and stabilising structure of any one of claims 1-7, wherein the arm connection portions are constructed and arranged to form snap fit connections with the arms extending from the patient interface.

9. The positioning and stabilising structure of any one of claims 1-8, wherein each lateral portion is at least partially formed in a layered construction.

10. The positioning and stabilising structure of claim 9, wherein the layered construction comprises a user-facing layer facing the user’s head in use and aA2578192 11.8 81rigi diser on the opposite side of the user-facing layer to the user’s head in use, the rigidiser forming the rigidised portion of the respective lateral portion and constructed and arranged to stiffen the respective lateral portion in the rigidised portion.

11. The positioning and stabilising structure of claim 10, wherein the rigidiser is formed in a non-planar shape and imparts a three-dimensional curved shape to the respective lateral portion.

12. The positioning and stabilising structure of claim 11, wherein the three- dimensional curved shape imparted to the lateral portions approximates curvature of a head surface that each lateral portion engages in use.

13. The positioning and stabilising structure of claim 11 or claim 12, wherein the rigidiser is able to flex away from the non-planar shape in use to conform to the shape of the user’s head.

14. The positioning and stabilising structure of any one of claims 10-13, wherein the layered construction comprises a non-user facing layer on an opposite side of the rigidiser to the user-facing layer.

15. The positioning and stabilising structure of claim 14, wherein regions of the lateral portion not occupied by the rigidiser are formed at least partially by the user-facing layer and the non-user facing layer.

16. The positioning and stabilising structure of any one of claims 10-15, wherein the layered construction comprises at least one stiffening layer proximate the arm connection portion.

17. The positioning and stabilising structure of claim 16, wherein the stiffening layer surrounds the arm connection portion.

18. The positioning and stabilising structure of claim 16 or claim 17, wherein the stiffening layer overlaps with the rigidiser.A2578192 11.8 8219. The positioning and stabilising structure of any one of claims 16-18, wherein the layered construction comprises two stiffening layers, the two stiffening layers overlapping with the rigidiser, a portion of the rigidiser being between the two stiffening layers.

20. The positioning and stabilising structure of any one of claims 16-19, wherein each of the at least one stiffening layer comprises a stiffening mesh.

21. The positioning and stabilising structure of any one of claims 1-20, wherein the frontal strap portion is adjustable in length.

22. The positioning and stabilising structure of claim 21, wherein the frontal strap portion comprises a first portion extending from one of the lateral portions, the first portion passing through an opening provided to the other of the lateral portions and being secured back to itself.

23. The positioning and stabilising structure of any one of claims 1-22, wherein the parietal strap portion is adjustable in length.

24. The positioning and stabilising structure of claim 23, wherein the parietal strap portion comprises a first portion extending from one of the lateral portions, the first portion passing through an opening provided to the other of the lateral portions and being secured back to itself.

25. The positioning and stabilising structure of any one of claims 1-24, wherein the occipital strap portion is adjustable in length.

26. The positioning and stabilising structure of claim 25, wherein the occipital strap portion comprises a first portion extending from one of the lateral portions, the first portion passing through an opening provided to the other of the lateral portions and being secured back to itself.A2578192 11.8 8327. The positioning and stabilising structure of any one of claims 1-26, wherein the parietal strap portion is constructed and arranged to support one or more counterweights.

28. The positioning and stabilising structure of claim 27, wherein the parietal strap portion is constructed and arranged to support a pair of counterweights, each spaced from and located on opposing sides of the mid-sagittal plane of the user’s head in use.

29. The positioning and stabilising structure of claim 27 or claim 28, wherein the lateral portions are constructed and arranged to support the pair of counterweights in the parietal strap portion.

30. The positioning and stabilising structure of any one of claims 27-29, wherein the one or more counterweights are configured to attach to the parietal strap portion with a hook-and-loop connection.

31. The positioning and stabilising structure of any one of claims 1-30, wherein the occipital strap portion is constructed and arranged to support one or more counterweights.

32. The positioning and stabilising structure of claim 31, wherein the occipital strap portion is constructed and arranged to support a pair of counterweights, each spaced from and located on opposing sides of the mid-sagittal plane of the user’s head in use.

33. The positioning and stabilising structure of claim 31 or claim 32, wherein the lateral portions are constructed and arranged to support the pair of counterweights in the occipital strap portion.

34. The positioning and stabilising structure of claim 33, wherein the one or more counterweights are configured to attach to the occipital strap portion with a hook-and-loop connection.A2578192 11.8 8435. A positioning and stabilising structure for a patient interface, the positioning and stabilising structure constructed and arranged to hold the patient interface in an operable position on the user’s head in use, the positioning and stabilising structure comprising: a pair of lateral portions each constructed and arranged to be positioned on a respective lateral side of the user’s head in use, wherein: each lateral portion comprises a respective one of a pair of arm connection portions each configured to be connected to a respective one of a pair of arms extending posteriorly from the patient interface on respective sides of the user’s head; and each lateral portion comprises a rigidised portion being stiffer than one or more adjacent portions; a frontal strap portion formed at least partially by the lateral portions, the frontal strap portion being constructed and arranged to engage the user’s head in use in a region overlying the frontal bone of the user’s head; a parietal strap portion formed at least partially by the lateral portions, the parietal strap portion constructed and arranged to engage the user’s head at a region overlying the parietal bones of the user’s head in use; an occipital strap portion formed at least partially by the lateral portions, the occipital strap portion constructed and arranged to engage the user’s head at a region overlying or lying inferior to the occipital bone of the user’s head in use; wherein each arm connection portion is constructed and arranged to fixedly connect to the respective one of the pair of arms extending posteriorly from the patient interface substantially without permitting rotation of the respective arm with respect to the arm connection portion.

36. The positioning and stabilising structure of claim 35, wherein the arm connection portions are constructed and arranged to fixedly connect to respective arms of the pair of arms extending posteriorly from the patient interface substantially without permitting rotation of the respective arms with respect to the rigidised portions.A2578192 11.8 8537. The positioning and stabilising structure of claim 35 or claim 36, wherein in use, the positioning and stabilising structure is able to support substantially the entire weight of the patient interface via the arm connection portions.

38. The positioning and stabilising structure of any one of claims 35-37, wherein the arm connection portions are constructed and arranged to form snap fit connections with the arms extending from the patient interface.

39. The positioning and stabilising structure of any one of claims 35-38, wherein each rigidised portion comprises a first portion located within the frontal strap portion, a second portion located within the parietal strap portion and a third portion located within the occipital strap portion.

40. The positioning and stabilising structure of any one of claims 35-39, wherein the lateral portions are able to conform to the shape of the user’s head.

41. The positioning and stabilising structure of any one of claims 35-40, wherein in each rigidised portion, the first portion, the second portion and the third portion of said rigidised portion are all able to flex with respect to each other.

42. The positioning and stabilising structure of any one of claims 35-41, wherein in each lateral portion, the respective rigidised portion extends from proximate the respective arm connection portion into each of the frontal strap portion, the parietal strap portion and the occipital strap portion.A2578192 11.8 86

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