WO2024178461A1 - Connectors for medical devices - Google Patents

Abstract

A headgear connector may include a retainer that may connect to a patient interface and include a first engagement structure, and a clip that may connect to a strap of the patient interface and include a second engagement structure. The first or second engagement structure may provide a female engagement structure, and the other of the first and second engagement structure may include a male engagement structure. The male engagement structure may include a post, projecting out from a surface, and a plurality of deflectable prongs, projecting out from the surface and positioned around the post. The female engagement structure may include a receiver defining an opening. The headgear connector may transition between an engaged state with the clip coupled to the retainer, and a disengaged state with the clip uncoupled from the retainer. The male engagement structure may be received within the female engagement structure in the engaged state.

Description

CONNECTORS FOR MEDICAL DEVICES

1 CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Application Nos. 63/487,093, filed February 27, 2023 and 63/517,007, filed August 1, 2023, each of which are incorporated herein by reference in their entirety.

2 BACKGROUND OF THE TECHNOLOGY

2.1 FIELD OF THE TECHNOLOGY

[0002] The present technology relates to one or more of the screening, diagnosis, monitoring, treatment, prevention and amelioration of respiratory-related disorders. The present technology also relates to medical devices or apparatus, and their use.

2.2 DESCRIPTION OF THE RELATED ART

2.2.1 Human Respiratory System and its Disorders

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

[0004] The airways include a series of branching tubes, which become narrower, shorter and more numerous as they penetrate deeper into the lung. The prime function of the lung is gas exchange, allowing oxygen to move from the inhaled air into the venous blood and carbon dioxide to move in the opposite direction. The trachea divides into right and left main bronchi, which further divide eventually into terminal bronchioles. The bronchi make up the conducting airways, and do not take part in gas exchange. Further divisions of the airways lead to the 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.

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

[0006] Examples of respiratory disorders include Obstructive Sleep Apnea (OSA), Cheyne-Stokes Respiration (CSR), respiratory insufficiency, Obesity Hypoventilation Syndrome (OHS), Chronic Obstructive Pulmonary Disease (COPD), Neuromuscular Disease (NMD) and Chest wall disorders. [0007] Obstructive Sleep Apnea (OSA), a form of Sleep Disordered Breathing (SDB), is characterised by events including occlusion or obstruction of the upper air passage during sleep. It results from a combination of an abnormally small upper airway and the normal loss of muscle tone in the region of the tongue, soft palate and posterior oropharyngeal wall during sleep. The condition causes the affected patient to stop breathing for periods typically of 30 to 120 seconds in duration, sometimes 200 to 300 times per night. It often causes excessive daytime somnolence, and it may cause cardiovascular disease and brain damage. The syndrome is a common disorder, particularly in middle aged overweight males, although a person affected may have no awareness of the problem, e.g. see US Patent No. 4,944,310 (Sullivan).

[0008] Cheyne-Stokes Respiration (CSR) is another form of sleep disordered breathing. CSR is a disorder of a patient's respiratory controller in which there are rhythmic alternating periods of waxing and waning ventilation known as CSR cycles. CSR is characterised by repetitive de-oxygenation and re-oxygenation of the arterial blood. It is possible that CSR is harmful because of the repetitive hypoxia. In some patients CSR is associated with repetitive arousal from sleep, which causes severe sleep disruption, increased sympathetic activity, and increased afterload, e.g. see US Patent No. 6,532,959 (Berthon-Jones).

[0009] Respiratory failure is an umbrella term for respiratory disorders in which the lungs are unable to inspire sufficient oxygen or exhale sufficient CO2 to meet the patient’s needs. Respiratory failure may encompass some or all of the following disorders.

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

[0011] Neuromuscular Disease (NMD) is a broad term that encompasses many diseases and ailments that impair the functioning of the muscles either directly via intrinsic muscle pathology, or indirectly via nerve pathology. Some NMD patients are characterised by progressive muscular impairment leading to loss of ambulation, being wheelchair-bound, swallowing difficulties, respiratory muscle weakness and, eventually, death from respiratory failure. Neuromuscular disorders can be divided into rapidly progressive and slowly progressive: (i) Rapidly progressive disorders: Characterised by muscle impairment that worsens over months and results in death within a few years (e.g. Amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers); (ii) Variable or slowly progressive disorders: Characterised by muscle impairment that worsens over years and only mildly reduces life expectancy (e.g. Limb girdle, Facioscapulohumeral and Myotonic muscular dystrophy). Symptoms of respiratory failure in NMD include: increasing generalised weakness, dysphagia, dyspnea on exertion and at rest, fatigue, sleepiness, morning headache, and difficulties with concentration and mood changes.

[0012] Chest wall disorders are a group of thoracic deformities that result in inefficient coupling between the respiratory muscles and the thoracic cage. The disorders are usually characterised by a restrictive defect and share the potential of long term hypercapnic respiratory failure. Scoliosis and/or kyphoscoliosis may cause severe respiratory failure. Symptoms of respiratory failure include: dyspnea on exertion, peripheral oedema, orthopnea, repeated chest infections, morning headaches, fatigue, poor sleep quality and loss of appetite.

[0013] 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

[0014] 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.

[0015] 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).

[0016] Continuous Positive Airway Pressure (CPAP) therapy has been used to treat Obstructive Sleep Apnea (OSA). The mechanism of action is that continuous positive airway pressure acts as a pneumatic splint and may prevent upper airway occlusion, such as by pushing the soft palate and tongue forward and away from the posterior oropharyngeal wall. Treatment of OSA by CPAP therapy may be voluntary, and hence patients may elect not to comply with therapy if they find devices used to provide such therapy one or more of: uncomfortable, difficult to use, expensive and aesthetically unappealing.

[0017] Non-invasive ventilation (NIV) provides ventilatory support to a patient through the upper airways to assist the patient breathing and/or maintain adequate oxygen levels in the body by doing some or all of the work of breathing. The ventilatory support is provided via a non-invasive patient interface. NIV has been used to treat CSR and respiratory failure, in forms such as OHS, COPD, NMD and Chest Wall disorders. In some forms, the comfort and effectiveness of these therapies may be improved.

[0018] Invasive ventilation (IV) provides ventilatory support to patients that are no longer able to effectively breathe themselves and may be provided using a tracheostomy tube or endotracheal tube. In some forms, the comfort and effectiveness of these therapies may be improved.

2.2.3 Respiratory Therapy Systems

[0019] 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.

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

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

2.2.3.1 Patient Interface

[0022] A patient interface may be used to interface respiratory equipment to its wearer, for example by providing a flow of air to an entrance to the airways. The flow of air may be provided via a mask to the nose and/or mouth, a tube to the mouth or a tracheostomy tube to the trachea of a patient. Depending upon the therapy to be applied, the patient interface may form a seal, e.g., with a region of the patient's face, to facilitate the delivery of gas at a pressure at sufficient variance with ambient pressure to effect therapy, e.g., at a positive pressure of about 10 cmH20 relative to ambient pressure. For other forms of therapy, such as the delivery of oxygen, the patient interface may not include a seal sufficient to facilitate delivery to the airways of a supply of gas at a positive pressure of about 10 cmFhO. For flow therapies such as nasal HFT, the patient interface is configured to insufflate the nares but specifically to avoid a complete seal. One example of such a patient interface is a nasal cannula. [0023] Certain mask systems may be functionally unsuitable for the present field. For example, purely ornamental masks may be unable to maintain a suitable pressure. Mask systems used for underwater swimming or diving may be configured to guard against ingress of water from an external higher pressure, but not to maintain air internally at a higher pressure than ambient.

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

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

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

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

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

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

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

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

[0032] Thus, a designer of a patient interface may be presented with an infinite number of choices to make. Design criteria may conflict structurally, functionally, and/or with patient- specific conditions (e.g., presence of certain types of implants), meaning that certain design choices are far from routine or inevitable. Furthermore, comfort and efficacy of certain aspects may be highly sensitive to small, subtle changes in one or more parameters.

[0033] For these reasons, patient interfaces for delivery of CPAP during sleep form a distinct field.

2.2.3.1.1 Seal-forming structure

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

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

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

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

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

[0039] Another type of seal-forming structure incorporates a flap seal of thin material positioned about the periphery of the mask so as to provide a self-sealing action against the face of the patient when positive pressure is applied within the mask. Like the previous style of seal forming portion, if the match between the face and the mask is not good, additional force may be required to achieve a seal, or the mask may leak. Furthermore, if the shape of the seal-forming structure does not match that of the patient, it may crease or buckle in use, giving rise to leaks. [0040] Another type of seal-forming structure may comprise a friction-fit element, e.g. for insertion into a naris, however some patients find these uncomfortable.

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

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

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

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

2.2.3.1.2 Positioning and Stabilising Structure

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

2.2.3.1.2.1 Adhesives for Positioning and Stabilising Structure

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

2.2.3.1.2.2 Straps for Positioning and Stabilising Structure

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

2.2.3.1.2.3 Headgear Connectors for Positioning and Stabilising Structure

[0048] Headgear connectors may contribute to the efficacy of a patient interface because of the role they play in one or more of: maintaining alignment between a seal forming structure and an appropriate sealing position; patient comfort as a result of affecting a directional component of strap forces, which may impact the application of tensile forces on a patient’s face and a patient’s skull in a region of the occipital bone; usability from a standpoint of ensuring a patient can put a patient interface on without undue effort; ensuring that the patient interface does not detach or come loose too easily; and overall patient compliance, at least to the extent that this factor depends on patient comfort and usability, both individually and in combination.

[0049] Many headgear connectors employ a pair of magnetic components to secure headgear (e.g., straps) to seal forming structures of patient interfaces.

However, many patients may find having magnets near their faces less than desirable. In addition, the use of magnets may be not appropriate for some patients due to one or more medical conditions these patients experience. Further still, sensory abilities of some patients to feel and hear aspects of magnetic headgear connectors engaging may be less than ideal.

[0050] On the other hand, some patients may want to have the option of using magnetic headgear connectors in some situations, and a non-magnetic headgear connector option in other situations.

[0051] From a manufacturing standpoint, magnetic headgear components may be more expensive and more difficult to obtain relative to components of a non-magnetic headgear option. This may particularly be true in instances of global supply shortages of certain materials. Further, manufacturing processes involving encasing magnets in other medical grade materials may be more complicated, time intensive, and expensive. All of these factors may hinder durable medical equipment providers’ abilities to timely deliver cost effective and affordable patient interface options to patients generally, and specifically to those patients with immediate needs.

[0052] These and other issues may be addressed with non-magnetic headgear connector options described herein that effectively secure seal forming structures in alignment with appropriate seal forming positions, and provide patient comfort and usability.

2.2.3.1.3 Pressurised Air Conduit

[0053] In one type of treatment system, a flow of pressurised air is provided to a patient interface through a conduit in an air circuit that fluidly connects to the patient interface at a location that is in front of the patient’s face when the patient interface is positioned on the patient’s face during use. The conduit may extend from the patient interface forwards away from the patient’s face.

2.2.3.1.4 Pressurised Air Conduit used for Positioning / Stabilising the Seal- Forming Structure

[0054] Another type of treatment system comprises a patient interface in which a tube that delivers pressurised air to the patient’s airways also functions as part of the headgear to position and stabilise the seal-forming portion of the patient interface at the appropriate part of the patient’s face. This type of patient interface may be referred to as having “conduit headgear” or “headgear tubing”. Such patient interfaces allow the conduit in the air circuit providing the flow of pressurised air from a respiratory pressure therapy (RPT) device to connect to the patient interface in a position other than in front of the patient’s face. One example of such a treatment system is disclosed in US Patent Publication No. US 2007/0246043, the contents of which are incorporated herein by reference, in which the conduit connects to a tube in the patient interface through a port positioned in use on top of the patient’s head.

[0055] It is desirable for patient interfaces incorporating headgear tubing to be comfortable for a patient to wear over a prolonged duration when the patient is asleep, form an air-tight and stable seal with the patient’s face, while also able to fit a range of patient head shapes and sizes. 2.2.3.2 Respiratory Pressure Therapy (RPT) Device

[0056] 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.

2.2.3.3 Air circuit

[0057] An air circuit is a conduit or a tube constructed and arranged to allow, in use, a flow of air to travel between two components of a respiratory therapy system such as the RPT device and the patient interface. In some cases, there may be separate limbs of the air circuit for inhalation and exhalation. In other cases, a single limb air circuit is used for both inhalation and exhalation.

2.2.3.4 Humidifier

[0058] Delivery of a flow of air without humidification may cause drying of airways. The use of a humidifier with an RPT device and the patient interface produces humidified gas that minimizes drying of the nasal mucosa and increases patient airway comfort. In addition, in cooler climates, warm air applied generally to the face area in and about the patient interface is more comfortable than cold air.

2.2.3.5 Data Management

[0059] There may be clinical reasons to obtain data to determine whether the patient prescribed with respiratory therapy has been “compliant”, e.g. that the patient has used their RPT device according to one or more “compliance rules”. One example of a compliance rule for CPAP therapy is that a patient, in order to be deemed compliant, is required to use the RPT device for at least four hours a night for at least 21 of 30 consecutive days. In order to determine a patient's compliance, a provider of the RPT device, such as a health care provider, may manually obtain data describing the patient's therapy using the RPT device, calculate the usage over a predetermined time period, and compare with the compliance rule. Once the health care provider has determined that the patient has used their RPT device according to the compliance rule, the health care provider may notify a third party that the patient is compliant. [0060] 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.

[0061] Existing processes to communicate and manage such data can be one or more of costly, time-consuming, and error-prone.

2.2.3.6 Vent technologies

[0062] Some forms of treatment systems may include a vent to allow the washout of exhaled carbon dioxide. The vent may allow a flow of gas from an interior space of a patient interface, e.g., the plenum chamber, to an exterior of the patient interface, e.g., to ambient.

2.2.4 Screening, Diagnosis, and Monitoring Systems

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

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

[0065] Clinical experts may be able to screen, diagnose, or monitor patients adequately based on visual observation of PSG signals. However, there are circumstances where a clinical expert may not be available, or a clinical expert may not be affordable. Different clinical experts may disagree on a patient’s condition. In addition, a given clinical expert may apply a different standard at different times. 3 BRIEF SUMMARY OF THE TECHNOLOGY

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

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

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

[0069] An aspect of certain forms of the present technology is to provide methods and/or apparatus that improve the compliance of patients with respiratory therapy. [0070] One form of the present technology comprises a positioning and stabilising structure configured to provide a force to hold the seal-forming structure in a therapeutically effective position on the patient’s head. The positioning and stabilising structure includes at least one strap.

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

[0072] One form of the present technology comprises patient interface comprising a plenum chamber pressurisable to a therapeutic pressure of at least 4 cm H2O above ambient air pressure. The plenum chamber includes at least one plenum chamber inlet port sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient. The patient interface also comprises a sealforming structure that is constructed and arranged to form a seal with a region of the patient’s face surrounding an entrance to the patient’s airways. The seal-forming structure has a hole therein such that the flow of air at said therapeutic pressure is delivered to at least an entrance to the patient’s nares. The seal-forming structure is constructed and arranged to maintain said therapeutic pressure in the plenum chamber throughout the patient’s respiratory cycle in use. The patient interface also comprises a positioning and stabilising structure to provide a force to hold the seal-forming structure in a therapeutically effective position on the patient’s head. [0073] Another aspect of one form of the present technology is a series of modular elements that may be interconnected in order to form different styles of patient interfaces.

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

[0075] One form of the present technology comprises a headgear connector comprising a retainer and a clip. The retainer may include a first engagement structure and may be configured to connect to a patient interface. The clip may include a second engagement structure and may be configured to connect to a strap of the patient interface. In some forms of the present technology, one of the first engagement structure or the second engagement structure includes a female engagement structure, and the other of the first engagement and the second engagement structure includes a male engagement structure. In some examples, the male engagement structure may include a post projecting out from a surface, and a plurality of deflectable prongs projecting out from the surface and positioned around the post. In other examples, the female engagement structure may include a receiver defining an opening. In some forms of the present technology, the headgear connector may be configured to transition between an engaged state in which the clip is coupled to the retainer and a disengaged state in which the clip is uncoupled from the retainer. In some examples, the male engagement structure may be received within the female engagement structure in the engaged state.

[0076] In examples of some forms of the present technology: a. the retainer includes the male engagement structure, and the clip includes the female engagement structure; b. the opening of the receiver extends completely through a first surface and a second surface, opposite the first surface; c. the male engagement structure has a height that is greater than a height of the opening so that the male engagement structure extends through the opening in the engaged state; d. the opening of the receiver extends through a first surface and terminates prior to a second surface, opposite the first surface; e. the male engagement structure includes two, three, or four deflectable prongs projecting out from the surface and surrounding the post; f. transitioning to the engaged state requires a force of about 1.0N to about 30.0N; g. transitioning from the engaged state to the disengaged state requires a force of about 1.0N to about 60. ON; h. the receiver has a first receiver surface, a second receiver surface, and a receiver transition located between the first receiver surface and the second receiver surface, and the receiver transition protrudes further into the opening of the receiver compared to the first receiver surface and the second receiver surface, i. each of the plurality of prongs includes an outwardly protruding ridge on a side of the prong facing away from the post, j. transitioning the headgear connector to the engaged state includes the outwardly protruding ridge on each of the plurality of prongs contacting the receiver transition as the male engagement structure is received within the female engagement structure and causing the plurality of prongs to deflect inwards towards the post; k. the outwardly protruding ridge of each of the plurality of prongs is located further into the receiver than the receiver transition in the engaged state; l. the retainer is removably coupled to the patient interface; m. the clip is removably coupled to the strap of the patient interface; and/or n. at least one of the clip and the retainer includes at least one of dimples, bumps, grooves, recesses, serrations, ridges, knurling, or texturing on a portion configured to be contacted by a patient.

[0077] One form of the present technology comprises a patient interface provided with a headgear including a first strap and a second strap, a seal forming structure, and headgear connectors. In some examples, at least one of the headgear connectors may include a retainer connected to the patient interface and a clip connected to a strap of the patient interface. In some forms of the present technology, the headgear connector including the retainer and the clip may be configured to transition between an engaged state in which the clip is coupled to the retainer and a disengaged state in which the clip is uncoupled from the retainer.

[0078] Another form of the present technology comprises a headgear connector comprising a retainer and a clip. The retainer may be configured to connect to a patient interface and include a male engagement structure. The clip may be configured to connect to a strap of the patient interface and include a female engagement structure. In some examples, the female engagement structure may include a receiver defining an opening and having a first receiver surface, a second receiver surface, and a receiver transition located between the first receiver surface and the second receiver surface. In other examples, the male engagement structure may include a post and a plurality of deflectable prongs encircling the post. According to aspects of one form of the present technology, each of the plurality of prongs may have an outwardly protruding ridge on a side facing away from the post. In some examples, the outwardly protruding ridges of the plurality of prongs form an imaginary circle having a diameter that is greater than a diameter of the opening at the receiver transition.

[0079] In an example, the opening of the receiver extends through opposite surfaces of the clip.

[0080] In another example, the male engagement structure includes two, three, or four deflectable prongs.

[0081] Another form of the present technology comprises a patient interface comprising a headgear having a first strap and a second strap, a seal forming structure, and a pair of headgear connectors. Each headgear connectors may include a retainer and a clip, with the clip being configured to connect to at least one of the first strap or the second strap. In one example, each headgear connector may include a receiver and a plurality of deflectable prongs. According to aspects of one or more forms of the present technology, for either headgear connector, the receiver may be incorporated in one of a respective clip and retainer, with the plurality of deflectable prongs incorporated in the other of the respective clip and retainer. According to other aspects of one or more forms of the present technology, for either headgear connector, a post may be incorporated in a respective clip or retainer independent of which of these components includes a respective receiver and plurality of deflectable prongs of the headgear connector. In some examples, each prong of at least one plurality of deflectable prongs may have an outwardly protruding ridge on a side facing away from a longitudinal axis of a respective post or opening of a respective clip or retainer including the at least one plurality of deflectable prongs. In some examples, outwardly protruding ridges of the respective plurality of deflectable prongs may form an imaginary circle having a diameter greater than a diameter of a respective opening at a corresponding receiver transition.

[0082] 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.

[0083] An aspect of one form of the present technology is a method of manufacturing apparatus.

[0084] Another aspect of one form of the present technology is a method of assembling a modular system comprising selecting a positioning and stabilising structure, and connecting the positioning and stabilising structure to either a first cushion or a second cushion.

[0085] An aspect of certain forms of the present technology is a medical device that is easy to use, e.g. by a person who does not have medical training, by a person who has limited dexterity, vision or by a person with limited experience in using this type of medical device.

[0086] 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.

[0087] An aspect of one form of the present technology is a patient interface that may be washed in a home of a patient, e.g., in soapy water, without requiring specialised cleaning equipment. An aspect of one form of the present technology is a humidifier tank that may be washed in a home of a patient, e.g., in soapy water, without requiring specialised cleaning equipment.

[0088] 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.

[0089] 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.

[0090] Other features of the technology will be apparent from consideration of the information contained in the following detailed description, abstract, drawings and claims.

4 BRIEF DESCRIPTION OF THE DRAWINGS

[0091] 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

[0092] Fig. 1A shows a system including a patient 1000 wearing a patient interface 3000, in the form of nasal pillows, receiving a supply of air at positive pressure from an RPT device 4000. Air from the RPT device 4000 is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000. A bed partner 1100 is also shown. The patient is sleeping in a supine sleeping position.

[0093] 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.

[0094] 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

[0095] Fig. 2A shows an overview of a human respiratory system including the nasal and oral cavities, the larynx, vocal folds, oesophagus, trachea, bronchus, lung, alveolar sacs, heart and diaphragm. [0096] 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.

[0097] 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.

[0098] Fig. 2D is a side view of a head with several features of surface anatomy identified including glabella, sellion, pronasale, subnasale, lip superior, lip inferior, supramenton, nasal ridge, alar crest point, otobasion superior and otobasion inferior. Also indicated are the directions superior & inferior, and anterior & posterior.

[0099] 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.

[0100] 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.

[0101] Fig. 2G shows a side view of the superficial features of a nose.

[0102] 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.

[0103] 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.

[0104] Fig. 2J 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.

[0105] 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.

[0106] Fig. 2L shows an anterolateral view of a nose.

4.3 PATIENT INTERFACE

[0107] Fig. 3A shows a patient interface and forces acting on the patient interface while in use.

[0108] Fig. 3B shows a schematic of a cross-section through a structure at a point. An outward normal at the point is indicated. The curvature at the point has a positive sign, and a relatively large magnitude when compared to the magnitude of the curvature shown in Fig. 3C.

[0109] Fig. 3C shows a schematic of a cross-section through a structure at a point. An outward normal at the point is indicated. The curvature at the point has a positive sign, and a relatively small magnitude when compared to the magnitude of the curvature shown in Fig. 3B.

[0110] Fig. 3D shows a schematic of a cross-section through a structure at a point. An outward normal at the point is indicated. The curvature at the point has a value of zero.

[0111] Fig. 3E shows a schematic of a cross-section through a structure at a point. An outward normal at the point is indicated. The curvature at the point has a negative sign, and a relatively small magnitude when compared to the magnitude of the curvature shown in Fig. 3F.

[0112] Fig. 3F shows a schematic of a cross-section through a structure at a point. An outward normal at the point is indicated. The curvature at the point has a negative sign, and a relatively large magnitude when compared to the magnitude of the curvature shown in Fig. 3E.

[0113] Fig. 3G shows a cushion for a mask that includes two pillows. An exterior surface of the cushion is indicated. An edge of the surface is indicated. Dome and saddle regions are indicated.

[0114] Fig. 3H shows a cushion for a mask. An exterior surface of the cushion is indicated. An edge of the surface is indicated. A path on the surface between points A and B is indicated. A straight line distance between A and B is indicated. Two saddle regions and a dome region are indicated. [0115] Fig. 31 shows the surface of a structure, with a one dimensional hole in the surface. The illustrated plane curve forms the boundary of a one dimensional hole.

[0116] Fig. 3J shows a cross-section through the structure of Fig.31. The illustrated surface bounds a two dimensional hole in the structure of Fig. 31.

[0117] Fig. 3K shows a perspective view of the structure of Fig. 31, including the two dimensional hole and the one dimensional hole. Also shown is the surface that bounds a two dimensional hole in the structure of Fig. 31.

[0118] Fig. 3L shows a mask having an inflatable bladder as a cushion.

[0119] Fig. 3M shows a cross-section through the mask of Fig. 3L, and shows the interior surface of the bladder. The interior surface bounds the two dimensional hole in the mask.

[0120] Fig. 3N shows a further cross-section through the mask of Fig. 3L. The interior surface is also indicated.

[0121] Fig. 30 illustrates a left-hand rule.

[0122] Fig. 3P illustrates a right-hand rule.

[0123] Fig. 3Q shows a left ear, including the left ear helix.

[0124] Fig. 3R shows a right ear, including the right ear helix.

[0125] Fig. 3S shows a right-hand helix.

[0126] Fig. 3T shows a view of a mask, including the sign of the torsion of the space curve defined by the edge of the sealing membrane in different regions of the mask.

[0127] Fig. 3U shows a view of a plenum chamber 3200 showing a sagittal plane and a mid-contact plane.

[0128] Fig. 3V shows a view of a posterior of the plenum chamber of Fig. 3U. The direction of the view is normal to the mid-contact plane. The sagittal plane in Fig. 3V bisects the plenum chamber into left-hand and right-hand sides.

[0129] Fig. 3W shows a cross-section through the plenum chamber of Fig. 3V, the cross-section being taken at the sagittal plane shown in Fig. 3 V. A ‘mid-contact’ plane is shown. The mid-contact plane is perpendicular to the sagittal plane. The orientation of the mid-contact plane corresponds to the orientation of a chord 3210 which lies on the sagittal plane and just touches the cushion of the plenum chamber at two points on the sagittal plane: a superior point 3220 and an inferior point 3230. Depending on the geometry of the cushion in this region, the mid-contact plane may be a tangent at both the superior and inferior points.

[0130] Fig. 3X shows the plenum chamber 3200 of Fig. 3U in position for use on a face. The sagittal plane of the plenum chamber 3200 generally coincides with the midsagittal plane of the face when the plenum chamber is in position for use. The mid-contact plane corresponds generally to the ‘plane of the face’ when the plenum chamber is in position for use. In Fig. 3X the plenum chamber 3200 is that of a nasal mask, and the superior point 3220 sits approximately on the sellion, while the inferior point 3230 sits on the lip superior.

[0131] Fig. 3Y shows a patient interface having conduit headgear, as well as forces acting on the patient interface while in use.

4.4 RPT DEVICE

[0132] Fig. 4A shows an RPT device in accordance with one form of the present technology.

[0133] Fig. 4B is a schematic diagram of the pneumatic path of an RPT device in accordance with one form of the present technology. The directions of upstream and downstream are indicated with reference to the blower and the patient interface. The blower is defined to be upstream of the patient interface and the patient interface is defined to be downstream of the blower, regardless of the actual flow direction at any particular moment. Items which are located within the pneumatic path between the blower and the patient interface are downstream of the blower and upstream of the patient interface.

4.5 HUMIDIFIER

[0134] Fig. 5A shows an isometric view of a humidifier in accordance with one form of the present technology.

[0135] Fig. 5B shows an isometric view of a humidifier in accordance with one form of the present technology, showing a humidifier reservoir 5110 removed from the humidifier reservoir dock 5130.

4.6 HEADGEAR AND MODULARITY

[0136] Fig. 6A shows a perspective view of a cushion of a patient interface configured to be worn by a patient and convey pressurized air to the patient’s nose and the patient’s mouth. 1 [0137] Fig. 6B shows a perspective view of a cushion of a patient interface configured to be worn by a patient and convey pressurized air to the patient’s nose. [0138] Fig. 6C shows a perspective view of tubes usable with either the cushion of Fig. 6A or the cushion of Fig. 6B.

[0139] Fig. 6D shows a perspective view of rigidiser arms usable with either the cushion of Fig. 6 A of the cushion of Fig. 6B.

[0140] Fig. 6E shows a perspective view of headgear straps usable with the cushion of Fig. 6A.

[0141] Fig. 6F shows a perspective view of headgear straps usable with the cushion of Fig. 6B.

[0142] Fig. 6G shows a front view of a pair of conduit sleeves that are removably fitted to either the tubes of Fig. 6C or the rigidiser arms of Fig. 6D.

[0143] Fig. 6H is a front view of a patient wearing the cushion of Fig. 6A connected to the tubes of Fig. 6C, the headgear straps of Fig. 6E, and the conduit sleeves of Fig. 6G.

4.7 HEADGEAR CONNECTORS

[0144] Fig. 7A shows a patient interface including a headgear connector in accordance with one form of the present technology.

[0145] Figs. 7B-7D respectively show overhead, side, and bottom perspective views of one disengaged portion of a headgear connector in accordance with one form of the present technology.

[0146] Figs. 7E-7G respectively show overhead, bottom, and side perspective views of another disengaged portion of a headgear connector.

[0147] Figs. 7H-7J show the portions of the headgear connector of Figs. 7B-7G in multiple states of engagement.

[0148] Fig. 7K shows a cross-sectional view of the engaged portions of the headgear connector from a plane corresponding to line 7K-7K from Fig. 7J, looking in a direction K as indicated in Fig. 7 J.

[0149] Figs. 7L-7P show a headgear connector in multiple states leading to disengagement in accordance with one form of the present technology.

[0150] Fig. 7Q shows a side perspective view of one disengaged portion of a headgear connector in accordance with one form of the present technology. [0151] Figs. 7R-7T show portions of a headgear connector including the portion of Fig. 7Q, in multiple states of engagement.

[0152] Figs. 7U-7W respectively show overhead, bottom, and side perspective views of another disengaged portion of a headgear connector.

[0153] Figs. 7X and 7Y show side views of alternative embodiments of the disengaged portion of the headgear connector of Figs. 7U-7W.

[0154] Fig. 7Z shows a cross-sectional view of the engaged portions of the headgear connector including the disengaged portion of Figs. 7U-7W from a plane corresponding to line 7K-7K from Fig. 7J, looking in a direction K as indicated in Fig.

7J.

[0155] Fig. 7AA shows a bottom view of a disengaged portion of a headgear connector.

[0156] Fig. 8 shows a perspective view of engaged portions of a headgear connector in accordance with one form of the present technology.

[0157] Fig. 9A shows a patient interface including a headgear connector in accordance with one form of the present technology.

[0158] Figs. 9B-9D respectively show overhead, bottom, and side perspective views of one disengaged portion of a headgear connector in accordance with one form of the present technology.

[0159] Figs. 9E-9G respectively show overhead, bottom, and side perspective views of another disengaged portion of a headgear connector in accordance with one form of the present technology.

[0160] Fig. 9H is a partial, perspective zoomed in view of a portion of the headgear connector of Fig. 9F.

[0161] Fig. 91 shows a cross-sectional view of a portion of the headgear connector from a plane corresponding to line 91-91 from Fig. 9E, looking in a direction I as indicated in Fig. 9E.

[0162] Fig. 9J shows a cross-sectional view of a portion of the headgear connector from a plane corresponding to line 9J-9J from Fig. 9F, looking in a direction J as indicated in Fig. 9F.

[0163] Fig. 9K shows a cross-sectional view of a portion of the headgear connector from a plane corresponding to line 9K-9K from Fig. 9G, looking in a direction K as indicated in Fig. 9G. [0164] Figs. 9L-9O show the portions of the headgear connector of Figs. 9B-9K in multiple states of engagement.

[0165] Fig. 10A shows a headgear connector attached to a patient interface in accordance with one form of the present technology.

[0166] Fig. 10B shows a post of an engagement structure for a retainer shown in Fig. 10A.

[0167] Fig. 10C shows a portion of the headgear connector of FIG. 10A in a disengaged state.

[0168] Figs. 10D-10G show the headgear connector of Fig. 10A in multiple states of engagement in accordance with one form of the present technology.

[0169] Fig. 10H shows a front view of the headgear connector of Fig. 10A in accordance with one form of the present technology.

[0170] Fig. 11A shows a patient interface including a headgear connector in a disengaged state in accordance with one form of the present technology.

[0171] Fig. 1 IB shows portions of the headgear connector of Fig. 11A in a disengaged state.

[0172] Fig. 11C shows portions of the headgear connector of Fig. 11A in an engaged state.

[0173] Fig. 1 ID shows a patient interface with a headgear connector in an engaged state (but without the headgear straps and without the plenum chamber) in accordance with one form of the present technology.

[0174] Fig. 12A shows portions of a headgear connector in a disengaged state in accordance with one form of the present technology.

[0175] Fig. 12B shows portions of the headgear connector of Fig. 12A in an engaged state.

5 DETAILED DESCRIPTION OF EXAMPLES OF THE

TECHNOLOGY

[0176] 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. [0177] 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

[0178] 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.

[0179] 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.

[0180] In certain examples of the present technology, mouth breathing is limited, restricted or prevented.

5.2 RESPIRATORY THERAPY SYSTEMS

[0181] 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

[0182] A non-invasive patient interface 3000, such as that shown in Fig. 3A, in accordance with one aspect of the present technology comprises the following functional aspects: a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilising structure 3300, a vent 3400, one form of connection port 3470 for connection to air circuit 4170, and a forehead support 3001. 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.

[0183] 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. [0184] The patient interface 3000 in accordance with one form of the present technology is constructed and arranged to be able to provide a supply of air at a positive pressure above the ambient, for example at least 2, 4, 6, 10, or 20 cm H2O with respect to ambient.

5.3.1 Seal-forming structure

[0185] 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.

[0186] In one form the target seal-forming region is located on an outside surface of the seal-forming structure 3100.

[0187] In certain forms of the present technology, the seal-forming structure 3100 is constructed from a biocompatible material, e.g. silicone rubber.

[0188] A seal-forming structure 3100 in accordance with the present technology may be constructed from a soft, flexible, resilient material such as silicone.

[0189] 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 Nasal pillows

[0190] 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.

[0191] 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.

5.3.1.2 Nose-only Masks

[0192] In one form, the patient interface 3000 comprises a seal-forming structure 3100 configured to seal around an entrance to the patient’s nasal airways but not around the patient’s mouth. The seal -forming structure 3100 may be configured to seal to the patient’s lip superior. The patient interface 3000 may leave the patient’s mouth uncovered. This patient interface 3000 may deliver a supply of air or breathable gas to both nares of patient 1000 and not to the mouth. This type of patient interface may be identified as a nose-only mask.

[0193] One form of nose-only mask according to the present technology is what has traditionally been identified as a “nasal mask”, having a seal-forming structure 3100 configured to seal on the patient’s face around the nose and over the bridge of the nose. A nasal mask may be generally triangular in shape. In one form, the non- invasive patient interface 3000 comprises a seal-forming structure 3100 that forms a seal in use to an upper lip region (e.g. the lip superior), to the patient’s nose bridge or at least a portion of the nose ridge above the pronasale, and to the patient's face on each lateral side of the patient’s nose, for example proximate the patient’s nasolabial sulci. The patient interface 3000 shown in Fig. IB has this type of seal-forming structure 3100. This patient interface 3000 may deliver a supply of air or breathable gas to both nares of patient 1000 through a single orifice.

[0194] Another form of nose-only mask may seal around an inferior periphery of the patient’s nose without engaging the user’s nasal ridge. This type of patient interface 3000 may be identified as a “nasal cradle” mask and the seal-forming structure 3100 may be identified as a “nasal cradle cushion”, for example.

[0195] In some forms, a nose-only mask may comprise nasal pillows, described above. 5.3.1.3 Nose and Mouth Masks

[0196] In one form, the patient interface 3000 comprises a seal-forming structure 3100 configured to seal around an entrance to the patient’s nasal airways and also around the patient’s mouth. The seal -forming structure 3100 may be configured to seal to the patient’s face proximate a chin region. This patient interface 3000 may deliver a supply of air or breathable gas to both nares and to the mouth of patient 1000. This type of patient interface may be identified as a nose and mouth mask.

[0197] One form of nose-and-mouth mask according to the present technology is what has traditionally been identified as a “full-face mask”, having a seal-forming structure 3100 configured to seal on the patient’s face around the nose, below the mouth and over the bridge of the nose. A nose-and-mouth mask may be generally triangular in shape. In one form the patient interface 3000 comprises a seal-forming structure 3100 that forms a seal in use to a patient’s chin-region (which may include the patient’s lip inferior and/or a region directly inferior to the lip inferior), to the patient’s nose bridge or at least a portion of the nose ridge superior to the pronasale, and to cheek regions of the patient's face. The patient interface 3000 shown in Fig. 1C is of this type. This patient interface 3000 may deliver a supply of air or breathable gas to both nares and mouth of patient 1000 through a single orifice. This type of sealforming structure 3100 may be referred to as a “nose-and-mouth cushion”.

[0198] In another form the patient interface 3000 comprises a seal-forming structure 3100 that forms a seal in use on a patient’s chin region (which may include the patient’s lip inferior and/or a region directly inferior to the lip inferior), to an inferior and/or an anterior surface of a pronasale portion of the patient’s nose, to the alae of the patient’s nose and to the patient’s face on each lateral side of the patient’s nose, for example proximate the nasolabial sulci. The seal-forming structure 3100 may also form a seal against a patient’s lip superior. A patient interface 3000 having this type of seal-forming structure may have a single opening configured to deliver a flow of air or breathable gas to both nares and mouth of a patient, may have an oral hole configured to provide air or breathable gas to the mouth and a nasal hole configured to provide air or breathable gas to the nares, or may have an oral hole for delivering air to the patient’s mouth and two nasal holes for delivering air to respective nares. This type of patient interface 3000 may have a nasal portion and an oral portion, the nasal portion sealing to the patient’s face at similar locations to a nasal cradle mask.

[0199] In a further form of nose and mouth mask, the patient interface 3000 may comprise a seal-forming structure 3100 having a nasal portion comprising nasal pillows and an oral portion configured to form a seal to the patient’s face around the patient’s mouth.

[0200] In some forms, the seal-forming structure 3100 may have a nasal portion that is separate and distinct from an oral portion. In other forms, a seal-forming structure 3100 may form a contiguous seal around the patient’s nose and mouth.

[0201] It is to be understood that the above examples of different forms of patient interface 3000 do not constitute an exhaustive list of possible configurations. In some forms a patient interface 3000 may comprise a combination of different features of the above described examples of nose-only and nose and mouth masks.

5.3.2 Plenum chamber

[0202] The plenum chamber 3200 has a perimeter that is shaped to be complementary to the surface contour of the face of an average person in the region where a seal will form in use. In use, a marginal edge of the plenum chamber 3200 is positioned in close proximity to an adjacent surface of the face. Actual contact with the face is provided by the seal-forming structure 3100. The seal-forming structure 3100 may extend in use about the entire perimeter of the plenum chamber 3200. In some forms, the plenum chamber 3200 and the seal-forming structure 3100 are formed from a single homogeneous piece of material.

[0203] 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.

[0204] 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. [0205] 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. [0206] In some forms, the plenum chamber 3200 is constructed from a rigid material such as polycarbonate. The rigid material may provide support to the sealforming structure.

[0207] In some forms, the plenum chamber 3200 is constructed from a flexible material (e.g., constructed from a soft, flexible, resilient material like silicone, textile, foam, etc.). For example, in examples then may be formed from a material which has a Young's modulus of 0.4 GPa or lower, for example foam. In some forms of the technology the plenum chamber 3200 may be made from a material having Young's modulus of 0.1 GPa or lower, for example rubber. In other forms of the technology the plenum chamber 3200 may be made from a material having a Young's modulus of 0.7MPa or less, for example between 0.7MPa and 0.3MPa. An example of such a material is silicone.

5.3.2.1 Multiple Openings

[0208] As shown in Figs. 6A and 6B, different plenum chambers 3200-1, 3200-2 may be formed as part of a multi-opening cushion 3050-1, 3050-2. In the illustrated examples, the cushions 3050-1, 3050-2 each include three openings, although an alternate cushion may be formed with greater or fewer openings.

[0209] In some forms, the different openings may serve different functions. For example, some openings may be exclusively inlet openings, while other openings may be exclusively outlet openings.

[0210] In other forms, at least one opening may serve two different functions. For example, one opening may operate as both an inlet and an outlet during the same breathing cycle.

[0211] The plurality of openings may allow for a variety of configurations of air delivery to the plenum chamber 3200-1, 3200-2. For example, depending on patient need and/or patient comfort, the patient may use a given cushion 3050-1, 3050-2 in a “tube-up” configuration (e.g., using conduit headgear - described below) or a “tubedown” configuration (e.g., using a single conduit in front of the patient’s face). 5.3.2.1.1 Nose and Mouth Mask

[0212] As shown in Fig. 6A, the plenum chamber 3200-1 includes a pair of plenum chamber inlet ports 3254-1, which may be used to convey gas into and/or out of the plenum chamber 3200-1. The plenum chamber inlet ports 3254-1 may be disposed on opposite sides (e.g., left and right sides) of the plenum chamber 3200-1. [0213] In some forms, the plenum chamber 3200-1 may also include at least one vent opening 3402-1 (see e.g., Fig. 6A). The vent opening 3402-1 may be disposed in a center of the plenum chamber 3200-1. For example, the vent opening 3402-1 may be disposed between the plenum chamber inlet ports 3254-1.

[0214] In some forms, the plenum chamber 3200-1 may include a pair of grooves 3266-1. Each groove 3266-1 may be disposed proximate to one of the plenum chamber inlet ports 3254-1. Each groove 3266-1 may form a partially recessed surface.

5.3.2.1.2 Nose-only Mask

[0215] The plenum chamber 3200-2 of a nasal only cushion 3050-2 may be similar to the plenum chamber 3200-1 of the mouth and nose cushion 3050-1. Only some similarities and differences between the plenum chambers 3200-1, 3200-2 may be described below.

[0216] As shown in Fig. 6B, the plenum chamber 3200-2 includes a pair of plenum chamber inlet ports 3254-2, which may be used to convey gas into and/or out of the plenum chamber 3200-2. The plenum chamber inlet ports 3254-2 may be disposed on opposite sides (e.g., left and right sides) of the plenum chamber 3200-2. [0217] In some forms, the plenum chamber 3200-2 may also include at least one vent opening 3402-2 (see e.g., Fig. 6B). The vent opening 3402-2 may be disposed in a center of the plenum chamber 3200-2. For example, the vent opening 3402-2 may be disposed between the plenum chamber inlet ports 3254-2.

[0218] In some forms, the plenum chamber 3200-2 may include a pair of grooves 3266-2. Each groove 3266-2 may be disposed proximate to one of the plenum chamber inlet ports 3254-2. Each groove 3266-2 may form a partially recessed surface.

5.3.3 Positioning and stabilising structure

[0219] The seal-forming structure 3100 of the patient interface 3000 of the present technology may be held in sealing position in use by the positioning and stabilising structure 3300. The positioning and stabilising structure 3300 may comprise and function as “headgear” since it engages the patient’s head in order to hold the patient interface 3000 in a sealing position. Examples of a positioning and stabilising structure may be shown in Figs. 3A.

[0220] In one form the positioning and stabilising structure 3300 provides a retention force at least sufficient to overcome the effect of the positive pressure in the plenum chamber 3200 to lift off the face (i.e., F_pienum).

[0221] 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.

[0222] With continued reference to Fig. 3A, the positioning and stabilising structure 3300 provides a force Fpss that assists in maintaining the plenum chamber 3200 in the sealing position on the patient’s face. The positioning and stabilising force Fpss may be the resultant force from the various forces of the different elements of the positioning and stabilising structure 3300. For example, headgear straps may individually provide a strap force F_strap in order to hold the seal-forming structure 3100 against the patient’s face. The force Fstrap may also be directed at least partially in the superior direction in order to overcome the gravitational force F_g. The gravitational force F_g may be specifically shown for the seal-forming structure 3100 and the plenum chamber 3200, but gravity would act on the entirely of the patient interface 3000 (i.e., in the same direction as the illustrated gravitational force F_g).

[0223] The gravitational force F_g may be opposed by a frictional force Ff, which may act in a direction directly opposite of the gravitational force F_g. As gravity pulls the seal-forming structure 3100 and the plenum chamber 3200 in the inferior direction (as viewed in Fig. 3A-1), the frictional force Ff would act in the superior direction (e.g., against a patient’s face). For example, the patient may experience the frictional force Ff against his lip superior (and/or other surfaces of the patient’s face in contact with the seal-forming structure 3100) in order to oppose the motion in the inferior direction (which may help to stabilising the cushion in place). Although the frictional force Ff is shown specifically opposing the gravitational force F_gof the seal-forming structure 3100 and the plenum chamber 3200, components of an overall frictional force (not shown) would also oppose the gravitational force F_g associated with the positioning and stabilising structure 3300 and any other portions of the patient interface 3000. A force of friction can act along any place where the patient interface 3000 contacts the patient’s skin (or hair). The frictional force Ff extends in the opposite direction of the gravitational force F_g and along the patient’s skin (or hair). In some forms the gravitational force F_g may also be countered by vertical components of the reaction force from the patient’s face acting on the seal -forming structure 3100, for example at the nose ridge and chin regions of the patient’s face, for example. [0224] In some forms, the sum of the various forces may equal zero so that the patient interface 3000 is at equilibrium (e.g., not moving along the patient’s face while in use). Specifically, the gravitational force F_g and the blowout force Fpienum tend to move the seal-forming structure 3100 away from the desired sealing position. The positioning and stabilising force Fpss is applied in order to counteract the gravitational force F_g and the blowout force Fpienum (as well as any frictional forces Ff) and keep the seal-forming structure 3100 properly situated. Although the positioning and stabilising force Fpss may exceed the sum of the gravitational force F_g and the blowout force Fpienum (with any additional positioning and stabilising force Fpss being balanced by reaction force from the patient’s head acting on the portions of patient interface 3000) and still maintain the seal-forming structure 3100 in an appropriate sealing position, patient comfort may be sacrificed. Maximum patient comfort may be achieved when the net force on the patient interface 3000 is zero and the positioning and stabilising force Fpss is exactly strong enough to achieve this. In some examples the positioning and stabilising structure 3300 may be adjustable such that when fitted the positioning and stabilising force Fpss is greater than required to exactly balance the gravitational force F_g and the blowout force Fpienum to hold the patient interface 3000 against the patient’s head tightly enough that disruptive forces which may be experienced in use (such as tube drag or lateral shunting of the plenum chamber 3200 during side sleeping) do not disrupt the seal. As described below, various positions of the patient’s head while using the patient interface 3000 may determine the positioning and stabilising force Fpss necessary to achieve equilibrium.

[0225] 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. [0226] In one form of the present technology, a positioning and stabilising structure 3300 is provided that is configured in a manner consistent with being worn by a patient while sleeping. In one example the positioning and stabilising structure 3300 has a low profile, or cross-sectional thickness, to reduce the perceived or actual bulk of the apparatus. In one example, the positioning and stabilising structure 3300 comprises at least one strap having a rectangular cross-section. In one example the positioning and stabilising structure 3300 comprises at least one flat strap.

[0227] 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.

[0228] 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.

[0229] 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.

[0230] 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. [0231] 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.

[0232] In one form of the present technology, the positioning and stabilising structure comprises a first tie, the first tie being constructed and arranged so that in use at least a portion of an inferior edge thereof passes superior to an otobasion superior of the patient’s head and overlays a portion of a parietal bone without overlaying the occipital bone.

[0233] 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.

[0234] 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.

[0235] 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.

[0236] 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,

[0237] In certain forms of the present technology, a system is provided comprising more than one positioning and stabilising structure 3300, each being configured to provide a retaining force to correspond to a different size and/or shape range. For example the system may comprise one form of positioning and stabilising structure 3300 suitable for a large sized head, but not a small sized head, and another, suitable for a small sized head, but not a large sized head.

5.3.3.1 Conduit headgear

5.3.3.1.1 Conduit headgear tubes

[0238] In some forms of the present technology, the positioning and stabilising structure 3300 comprises one or more headgear tubes 3350 that deliver pressurised air received from a conduit forming part of the air circuit 4170 from the RPT device to the patient’s airways, for example through the plenum chamber 3200 and sealforming structure 3100. In the form of the present technology illustrated in Figs. 3Y, 6C, and 6H, an exemplary positioning and stabilising structure 3300 comprises two tubes 3350 that deliver air to the plenum chamber 3200 from the air circuit 4170. The tubes 3350 are configured to position and stabilise the seal-forming structure 3100 of the patient interface 3000 at the appropriate part of the patient’s face (for example, the nose and/or mouth) in use. This allows the conduit of air circuit 4170 providing the flow of pressurised air to connect to a connection port 3470 (see e.g., Fig. 3Y) of the patient interface in a position other than in front of the patient’s face, for example on top of the patient’s head.

[0239] In the form of the present technology illustrated in Fig. 3Y, the positioning and stabilising structure 3300 comprises two tubes 3350, each tube 3350 being positioned in use on a different side of the patient’s head and extending across the respective cheek region, above the respective ear (superior to the otobasion superior on the patient’s head) to the elbow 3475 on top of the head of the patient 1000. This form of technology may be advantageous because, if a patient sleeps with their head on its side and one of the tubes 3350 is compressed to block or partially block the flow of gas along the tube 3350, the other tube 3350 remains open to supply pressurised gas to the patient. In other examples of the technology, the patient interface 3000 may comprise a different number of tubes, for example one tube, or two or more tubes.

[0240] In one example in which the patient interface has one tube 3350, the single tube 3350 is positioned on one side of the patient’s head in use (e.g. across one cheek region) and a strap forms part of the positioning and stabilising structure 3300 and is positioned on the other side of the patient’s head in use (e.g. across the other region) to assist in securing the patient interface 3000 on the patient’s head. For example, the tube 3350 and the strap may each be under tension in use in order to assist in maintaining the seal-forming structure 3100 in a sealing position.

[0241] In one form, the tube 3350 may be at least partially extensible so that the tube 3350 and the strap may adjust substantially equal lengths when worn by a patient. This may allow for substantially symmetrical adjustments between the tube 3350 and the strap so that the seal-forming structure remains substantially in the middle.

[0242] In the form of the technology shown in Figs. 3Y, the two tubes 3350 are fluidly connected at superior ends to each other and to the connection port 3470. In some examples, the two tubes 3350 are integrally formed while in other examples the tubes 3350 are formed separately but are connected in use and may be disconnected, for example for cleaning or storage. Where separate tubes are used, they may be indirectly connected together, for example each may be connected to a T-shaped connector. The T-shaped connector may have two arms/branches each fluidly connectable to a respective one of the tubes 3350. Additionally, the T-shaped connector may have a third arm or opening providing the connection port 3470 for fluid connection to the air circuit 4170 in use. The opening may be an inlet 3332 (see e.g., Figs. 6C and 6H) for receiving the flow of pressurized air.

[0243] In some forms, the third arm of the T-shaped connector may be substantially perpendicular to each of the first two arms.

[0244] In some forms, the third arm of the T-shaped connector may be obliquely formed with respect to each of the first two arms.

[0245] In some forms, a Y-shaped connector may be used instead of the T-shaped connector. The first two arms may be oblique with respect to one another, and the third arm may be oblique with respect to the first two arms. The angled formation of the first two arms may be similar to the shape of the patient’s head in order to conform to the shape.

[0246] In some forms, at least one of the arms of the T-shaped connector (or Y- shaped connector) may be flexible. This may allow the connector to bend based on the shape of the patient’s head and/or a force in the positioning and stabilising structure 3300.

[0247] In some forms, at least one of the arms of the T-shaped connector (or Y- shaped connector) may be at least partially rigidised. This may assist in maintaining the shape of the connector so that bending of the connector does not close the airflow path.

[0248] The tubes 3350 may be formed from a flexible material, such as an elastomer, e.g. silicone or TPE, and/or from one or more textile and/or foam materials. The tubes 3350 may have a preformed shape and may be able to be bent or moved into another shape upon application of a force but may return to the original preformed shape in the absence of said force. The tubes 3350 may be generally arcuate or curved in a shape approximating the contours of a patient’s head between the top of the head and the nasal or oral region.

[0249] In some examples, the one or more tubes 3350 are crush resistant to resist being blocked if crushed during use, for example if squashed between a patient’s head and pillow, especially if there is only one tube 3350. The tubes 3350 may be formed with a sufficient structural stiffness to resist crushing or may be as described in US Patent No. 6,044,844, the contents of which are incorporated herein by reference. [0250] Each tube 3350 may be configured to receive a flow of air from the connection port 3470 on top of the patient’s head and to deliver the flow of air to the seal-forming structure 3100 at the entrance of the patient’s airways. In the examples shown in Fig. 3Y and 6H, each tube 3350 lies in use on a path extending from the plenum chamber 3200 across the patient’s cheek region and superior to the patient’s ear to the elbow 3475. For example, a portion of each tube 3350 proximate the plenum chamber 3200 may overlie a maxilla region of the patient’s head in use. Another portion of each tube 3350 may overlie a region of the patient’s head superior to an otobasion superior of the patient’s head. Each of the tubes 3350 may also lie over the patient’s sphenoid bone and/or temporal bone and either or both of the patient’s frontal bone and parietal bone. The elbow 3475 may be located in use over the patient’s parietal bone, over the frontal bone and/or over the junction therebetween (e.g. the coronal suture).

[0251] In certain forms of the present technology the patient interface 3000 is configured such that the connection port 3470 can be positioned in a range of positions across the top of the patient’s head so that the patient interface 3000 can be positioned as appropriate for the comfort or fit of an individual patient. In some examples, the headgear tubes 3350 are configured to allow movement of an upper portion of the patient interface 3000 (e.g. a connection port 3470) with respect to a lower portion of the patient interface 3000 (e.g. a plenum chamber 3200). That is, the connection port 3470 may be at least partially decoupled from the plenum chamber 3200. In this way, the seal-forming structure 3100 may form an effective seal with the patient’s face irrespective of the position of the connection port 3470 (at least within a predetermined range of positions) on the patient’s head. [0252] As described above, in some examples of the present technology the patient interface 3000 comprises a seal-forming structure 3100 in the form of a cradle cushion which lies generally under the nose and seals to an inferior periphery of the nose (e.g. an under-the-nose cushion). The positioning and stabilising structure 3300, including the tubes 3350 may be structured and arranged to pull the seal-forming structure 3100 into the patient’s face under the nose with a sealing force in a posterior and superior direction (e.g. a posterosuperior direction). A sealing force with a postero superior direction may cause the seal-forming structure 3100 to form a good seal to both the inferior periphery of the patient’s nose and anterior-facing surfaces of the patient’s face, for example on either side of the patient’s nose and the patient’s lip superior.

[0253] Conduits forming part of the positioning and stabilising structure 3300, like headgear straps, may provide a force that contributes to the positioning and stabilising force Fpss. As illustrated in Figs. 3Y, the positioning and stabilising force Fpss may be the resultant force from the various forces of the different elements of the positioning and stabilising structure 3300. For example, each conduit may provide a force Fconduit directed in the posterior and respective lateral direction in order to hold the seal-forming structure 3100 against the patient’s face (into the upper lip and sealing under the nose) and oppose the effect of the positive pressure in the plenum chamber 3200 to lift off the face (i.e., Fpienum). The force Fconduit directed may also be directed at least partially in the superior direction in order to overcome the gravitational force F_g.

[0254] In some forms, the conduits may provide a force directed into the patient’s head when the conduits are filled with pressurized air. The force may assist in gripping the patient’s head. The force may be caused by the inflation of the conduits during normal use. In some forms, the force may provide a cushioning effect to the patient’s head. The conduits may be designed in order to limit expansion in order to prevent over-gripping the patient’s head.

[0255] The position of the patient’s head may also change the gripping force of the conduits. For example, if the patient is sleeping on his side, the weight of the patient’s head may compress one conduit, and the other conduit (e.g., the lateral portion not between the patient’s head and a sleeping surface, like a pillow) may additionally expand in order to keep substantially the same flow rate of pressurized air.

[0256] The gravitational force F_g may be opposed by a frictional force Ff, which may act in a direction directly opposite of the gravitational force F_g. As gravity pulls the seal-forming structure 3100 and the plenum chamber 3200 in the inferior direction (as viewed in Fig. 3A), the frictional force Ff would act in the superior direction (e.g., against a patient’s face). For example, the patient may experience the frictional force Ff against his lip superior (and/or other surfaces of the patient’s face in contact with the seal-forming structure 3100) in order to oppose the motion in the inferior direction (which may help to stabilising the cushion in place). Although the frictional force Ff is shown specifically opposing the gravitational force F_g of the seal-forming structure 3100 and the plenum chamber 3200, components of an overall frictional force (not shown) would also oppose the gravitational force F_g associated with the positioning and stabilising structure 3300 and any other portions of the patient interface 3000. A force of friction can act along any place where the patient interface 3000 contacts the patient’s skin (or hair). The frictional force Ff extends in the opposite direction of the gravitational force F_g and along the patient’s skin (or hair).

[0257] In some forms, the sum of the various forces may equal zero so that the patient interface 3000 is at equilibrium (e.g., not moving along the patient’s face while in use). Specifically, the gravitational force F_g and the blowout force Fpienum tend to move the seal-forming structure 3100 away from the desired sealing position. The positioning and stabilising force Fpss is applied in order to counteract the gravitational force F_g and the blowout force Fpienum (as well as any frictional forces Ff) and keep the seal-forming structure 3100 properly situated. Although the positioning and stabilising force Fpss may exceed the sum of the gravitational force F_g and the blowout force Fpienum (with any additional positioning and stabilising force Fpss being balanced by reaction force from the patient’s head acting on the portions of patient interface 3000) and still maintain the seal-forming structure 3100 in an appropriate sealing position, patient comfort may be sacrificed. Maximum patient comfort may be achieved when the net force on the patient interface 3000 is zero and the positioning and stabilising force Fpss is exactly strong enough to achieve this. In some examples the positioning and stabilising structure 3300 may be adjustable such that when fitted the positioning and stabilising force Fpss is greater than required to exactly balance the gravitational force F_g and the blowout force Fpienum to hold the patient interface 3000 against the patient’s head tightly enough that disruptive forces which may be experienced in use (such as tube drag or lateral shunting of the plenum chamber 3200 during side sleeping) do not disrupt the seal. As described below, various positions of the patient’s head while using the patient interface 3000 may determine the positioning and stabilising force Fpss necessary to achieve equilibrium.

5.3.3.1.2 Extendable and non-extendable tube portions

[0258] In some examples of the present technology, one or both of the tubes 3350 are not extendable in length. However, in some forms, the tubes 3350 may comprise one or more extendable tube sections, for example formed by an extendable concertina structure. In some forms, the patient interface 3000 may comprise a positioning and stabilising structure 3300 including at least one gas delivery tube comprising a tube wall having an extendable concertina structure. The patient interface 3000 shown in Fig. 3Y comprises tubes 3350, the superior portions of which comprise extendable tube sections each in the form of an extendable concertina structure 3328.

[0259] In some forms, the extendable concertina structure 3328 may be formed as a series of ridges and grooves on the surface of the tubes 3350. The concertina structure 3328 may be biased toward a retracted position, and may move to an expanded position when the patient dons the positioning and stabilising structure 3300. Because portions of the tubes 3350 may be substantially inextensible (e.g., non- extendable tube sections 3363), the concertina structures 3328 permit the positioning and stabilising structure 3300 to stretch in order to fit different sized heads. This may allow a single sized tube 3350 to be used with multiple sized heads. For example, the positioning and stabilising structure 3300 may be “one-size-fits-all” as a result of the concertina structure 3328. Alternatively, the tubes 3350 may be manufactured in multiple sizes (e.g., small, medium, large). The patient may select a length that most closely conforms to their head, and the concertina structures 3328 may make small adjustments in order to tailor the fit to the individual patient.

[0260] In some forms, the inlet 3332 may be disposed in the middle of the conduit. For example, the tubes 3350 may be symmetric about the inlet 3332 through at least one axis. [0261] The cross-sectional shape of the non-extendable tube sections 3363 of the tubes 3350 may be circular, elliptical, oval, D-shaped or a rounded rectangle, for example as described in US Patent No. 6,044,844. A cross-sectional shape that presents a flattened surface of tube on the side that faces and contacts the patient’s face or other part of the head may be more comfortable to wear than, for example a tube with a circular cross- section.

[0262] In some examples of the present technology, the non-extendable tube sections 3363 connects to the plenum chamber 3200 from a low angle. The headgear tubes 3350 may extend inferiorly down the sides of the patient’s head and then curve anteriorly and medially to connect to the plenum chamber 3200 in front of the patient’s face. The tubes 3350, before connecting to the plenum chamber 3200, may extend to a location at the same vertical position as (or, in some examples, inferior to) the connection with the plenum chamber 3200. That is, the tubes 3350 may project in an at least partially superior direction before connecting with the plenum chamber 3200. A portion of the tubes 3350 may be located inferior to the plenum chamber 3200 and/or the seal-forming structure 3100. The tubes 3350 may contact the patient’s face below the patient’s cheekbones, which may be more comfortable than contact on the patient’s cheekbones and may avoid excessively obscuring the patient’s peripheral vision.

5.3.3.1.3 Conduit headgear connection port

[0263] In certain forms of the present technology, the patient interface 3000 may comprise a connection port 3470 located proximal to a superior, lateral or posterior portion of a patient’s head. For example, in the form of the present technology illustrated in Fig. 3Y, the connection port 3470 is located on top of the patient’s head (e.g. at a superior location with respect to the patient’s head). In this example the patient interface 3000 comprises an elbow 3475 forming the connection port 3470. The elbow 3475 may be configured to fluidly connect with a conduit of an air circuit 4170. The elbow 3475 may be configured to swivel with respect to the positioning and stabilising structure 3300 to at least partially decouple the conduit from the positioning and stabilising structure 3300. In some examples the elbow 3475 may be configured to swivel by rotation about a substantially vertical axis and, in some particular examples, by rotation about two or more axes. In some examples the elbow may comprise or be connected to the tubes 3350 by a ball-and-socket joint. The connection port 3470 may be located in the sagittal plane of the patient’s head in use. [0264] Patient interfaces having a connection port that is not positioned anterior to the patient’s face may be advantageous as some patients may find a conduit that connects to a patient interface anterior to their face to be unsightly and/or obtrusive. For example, a conduit connecting to a patient interface anterior to the patient’s face may be prone to interference with bedclothes or bed linen, particularly if the conduit extends inferiorly from the patient interface in use. Forms of the present technology comprising a patient interface having a connection port positioned superiorly to the patient’s head in use may make it easier or more comfortable for a patient to lie or sleep in one or more of the following positions: a side-sleeping position, a supine position (e.g. on their back, facing generally upwards) or in a prone position (e.g. on their front, facing generally downwards). Moreover, connecting a conduit to an anterior portion of a patient interface may exacerbate a problem known as tube drag in which the conduit exerts an undesired force upon the patient interface during movement of the patient’s head or the conduit, thereby causing dislodgement away from the face. Tube drag may be less of a problem when force is received at a superior location of the patient’s head than anterior to the patient’s face proximate to the seal-forming structure (where tube drag forces may be more likely to disrupt the seal).

5.3.3.1.4 Headgear Tube Fluid Connections

[0265] The two tubes 3350 are fluidly connected at their inferior ends to the plenum chamber 3200. In certain forms of the technology, the connection between the tubes 3350 and the plenum chamber 3200 is achieved by connection of two rigid connectors. The tubes 3350 and plenum chamber 3200 may be configured to enable the patient to easily connect the two components together in a reliable manner. The tubes 3350 and plenum chamber 3200 may be configured to provide tactile and/or audible feedback in the form of a ‘re-assuring click’ or a similar sound, so that the patient may easily know that each tube 3350 has been correctly connected to the plenum chamber 3200. In one form, the tubes 3350 are formed from a silicone or textile material and the inferior end of each of the silicone tubes 3350 is overmolded to a rigid connector made, for example, from polypropylene, polycarbonate, nylon or the like. The rigid connector on each tube 3350 may comprise a female engagement structure configured to connect with a male engagement structure on the plenum chamber 3200. Alternatively, the rigid connector on each tube 3350 may comprise a male engagement structure configured to connect to a female engagement structure on the plenum chamber 3200. In other examples the tubes 3350 may each comprise a male or female connector formed from a flexible material, such as silicone or TPE, for example the same material from which the tubes 3350 are formed.

[0266] In other examples a compression seal is used to connect each tube 3350 to the plenum chamber 3200. For example, a resiliently flexible (e.g. silicone) tube 3350 without a rigid connector may be configured to be squeezed to reduce its diameter so that it can be compressed into a port in the plenum chamber 3200 and the inherent resilience of the silicone pushes the tube 3350 outwards to seal the tube 3350 in the port in an air-tight manner. Alternatively, in a hard-to-hard type engagement between the tube 3350 and the plenum chamber 3200, each tube 3350 and/or plenum chamber 3200 may comprise a pressure activated seal, for example a peripheral sealing flange. When pressurised gas is supplied through the tubes 3350 the sealing flange may be urged against the join between the tubes and a circumferential surface around a port or connector of the plenum chamber 3200 to form or enhance a seal between the tube 3350 and plenum chamber 3200.

5.3.3.2 Headgear

[0267] In some forms, the positioning and stabilising structure 3300 may include headgear 3302 with at least one strap which may be worn by the patient in order to assist in properly orienting the seal-forming structure 3100 against the patient’s face (e.g., in order to limit or prevent leaks).

[0268] As described above, some forms of the headgear 3302 may be constructed from a textile material, which may be comfortable against the patient’s skin. The textile may be flexible in order to conform to a variety of facial contours. Although the textile may include rigidisers along a selected length, which may limit bending, flexing, and/or stretching of the headgear 3302.

[0269] In certain forms, the headgear 3302 may be at least partially extensible. For example, the headgear 3302 may include elastic, or a similar extensible material. For example, the entire headgear 3302 may be extensible or selected portions may be extensible (or more extensible than surrounding portions). This may allow the headgear 3302 to stretch while under tension, which may assist in providing a sealing force for the seal-forming structure 3100.

[0270] Two forms of the headgear, a four-point headgear 3302-1 and a two-point headgear 3302-2, are discussed in more detail below as illustrative examples.

5.3.3.2.1 Four-point connection

[0271] As shown in Fig. 6E, some forms of the headgear 3302-1 may be a four- point connection headgear. This means that the headgear 3302-1 may connect to four separate places on the plenum chamber 3200, on a frame connected to the plenum chamber 3200, and/or on arms connected to the plenum chamber 3200. The headgear 3302-1 may include four different straps providing a tensile force to help maintain the seal-forming structure 3100 in a sealing position. The positioning and stabilising structure 3300 of Fig. 3A may also be considered a four-point connection headgear. [0272] In some forms, the headgear 3302-1 may include inferior straps 3304-1, which may connect to an inferior portion of the cushion 3050-1. The inferior straps

3304-1 may extend along the patient’s cheek toward a posterior region of the patient’s head. For example, the inferior straps 3304-1 may overlay the masseter muscle on either side of the patient’s face. The inferior straps 3304-1 may therefore contact the patient’s head below the patient’s ears. The inferior straps 3304-1 may meet at the posterior of the patient’s head, and may overlay the occipital bone and/or the trapezius muscle.

[0273] The headgear 3302-1 may also include superior straps 3305-1, which may overlay the temporal bones, parietal bone, and/or occipital bone. The superior straps

3305-1 may also connect to the tubes 3350 (e.g., by interfacing with the tabs 3320). [0274] A rear strap 3307-1 may extend between the superior straps 3305-1 and between the inferior straps 3304-1. The inferior and superior straps 3304-1, 3305-1 on a given side (e.g., left or right) may also be connected to the rear strap 3307-1 adjacent to one another. The height of the rear strap 3307-1 may therefore be approximately the combined height of the inferior and superior strap 3304-1, 3305-1. The rear strap 3307-1 may overlay the occipital bone and/or the pariental bone in use. This may allow the rear strap 3307-1 to assist in anchoring the headgear 3302-1 to the patient’s head.

[0275] In the illustrated example, the headgear 3302-1 may be formed with a substantially X-shape. The inferior and superior straps 3304-1, 3305-1 may be connected to a rear strap 3307-1 using stitching, ultrasonic welding, or any similar process.

[0276] In some forms, the inferior straps 3304-1 may be connected to a portion of a headgear connector, which may be an exemplary clip 3800-1, 3800-2, 3800-3, 3800- 4, 3800-5, 3800-6 (see e.g., Figs. 7E, 8, 9F, 10C, 11B, and 12A) of the present technology described in more detail below. For example, each inferior strap 3304-1 may be threaded through a clip 3800-1, 3800-2, 3800-3, 3800-4, 3800-5, 3800-6, so that a length of each inferior strap 3304-1 may be adjusted. The clip 3800-1, 3800-2, 3800-3, 3800-4, 3800-5, 3800-6 may removably connect to an exemplary retainer 3700-1, 3750-1, 3700-2, 3700-3, 3700-4, 3700-5, 3700-6 (see e.g., Figs. 7B, 7Q, 8, 9B, 10B, 11B, and 12A) of the present technology, so that the inferior straps 3304-1 may be disconnected from the plenum chamber 3200, but the length of the inferior straps 3304-1 may not be affected. For example, clip 3800-1 includes a crossbar 7504 as shown in Fig. 7E through which a strap, such as the inferior straps 3304-1 may be passed to secure the clip 3800-1 thereto. In other aspects, instead of a crossbar 7504, clip 3800-1 may include one or more slots or other suitable mechanisms around or through which a strap may be passed to secure the clip 3800-1 thereto. In still other examples, any of the clips described herein may include a slide that connects to a base such as slide 10570 and base 10512 of the clip 3800-4 depicted in Figs. 10A-10H.

[0277] In some forms, the superior straps 3305-1 may be connected directly to the tabs 3320 of the tubes 3350. The superior straps 3305-1 may be threaded through the tabs 3320 in order to adjust the length and control the tensile force of each superior strap 3305-1.

[0278] In some forms, the headgear 3302-1 may be used only with the nose and mouth cushion 3050-1 (e.g., because the nose-only cushion 3050-1 does not have four connection points). However, the headgear 3302-1 may be used interchangeably with the tubes 3350 and rigidiser arms 3340 shown in Fig. 6D.

5.3.3.2.2 Two-point connection

[0279] As shown in Fig. 6F, some forms of the headgear 3302-2 may be a two- point connection headgear. This means that the headgear 3302-2 may connect to two separate places. The headgear strap 3310 included with the positioning and stabilising structure 3300 shown in Fig. 3Y being an example of a two-point connection. [0280] In certain forms of the present technology, the positioning and stabilising structure 3300, as shown in Fig. 3Y, comprises at least one headgear strap 3310 acting in addition to the tubes 3350 to position and stabilise the seal-forming structure 3100 at the entrance to the patient’s airways. The patient interface 3000 comprises the strap 3310 forming part of the positioning and stabilising structure 3300. The strap 3310 may be known as a back strap or a rear headgear strap, for example. The rear strap 3310 may overlay the temporal bones, parietal bone, and/or occipital bone.

[0281] More specifically, with further reference to Fig. 3Y, the strap 3310 of the positioning and stabilising structure 3300 may be connected between the two tubes 3350 positioned on each side of the patient’s head and passing around the back of the patient’s head, for example overlying or lying inferior to the occipital bone of the patient’s head in use. The strap 3310 connects to each tube above the patient’s ears. The positioning and stabilising structure 3300 may comprise a pair of the tabs 3320. In use, the strap 3310 may be connected between the tabs 3320. The strap 3310 may be sufficiently flexible to pass around the back of the patient’s head and lie comfortably against the patient’s head, even when under tension in use.

[0282] In other examples of the present technology, one or more further straps may be provided. For example, patient interfaces 3000 according to examples of the present technology having a nose-and-mouth cushion may have a second, lower, strap configured to lie against the patient’s head proximate the patient’s neck and/or against posterior surfaces of the patient’s neck.

[0283] Turning to Fig. 6F, in some forms of the present technology, the headgear 3302-2 may be formed from a continuous piece of material. In other words, the headgear 3302-2 may not be formed from multiple straps connected (e.g., stitched) together. This may be comfortable for a patient as they will not be in contact with any seams or joints connecting different straps. In other forms, the headgear 3302-2 may be formed from multiple straps (e.g., two superior straps, a rear strap, etc.) that are connected together (e.g., with stitching, ultra-sonic welding, etc.).

[0284] As shown in Fig. 6F, some forms of the headgear 3302-2 may be at least partially bifurcated. For example, a rear strap 3307-2 of the headgear 3302-2 (e.g., configured to contact the posterior portion of the patient’s head) may be wider than the surrounding portions of the headgear 3302-2. An intermediate section 3308-2 of the rear strap 3307-2 may include a slit 3309-2. A superior section of the rear strap 3307-2 may therefore be movable relative to the inferior section as a result of the slit 3309-2. This may allow the patient to have a larger strap coverage on the posterior region of their head, which may assist in better anchoring the headgear 3302-2 to the patient’s head since there is no inferior strap (e.g., 3304-1).

[0285] In some forms, the headgear 3302-2 may be used only with the nasal cushion 3050-2 (e.g., because the nose and mouth cushion 3050-1 does not have four connection points). However, the headgear 3302-2 may be used interchangeably with the tubes 3350 and the rigidiser arms 3340.

5.3.3.3 Connection Points

[0286] In some forms of the present technology, a patient interface may include connection points where a connection member, such as a retainer of a headgear connector, may be located. The connection point may define a location on the patient interface to which a headgear (e.g., headgear 3302-1, 3302-2) is anchored to thereby secure the patient interface to an individual. The connection point, both in location and form, may vary at least in part according to structural features of a plenum chamber and/or components extending from and attached thereto, or the type of patient interface onto which the connection point is on.

[0287] As one of ordinary skill will appreciate, a configuration of the connection point may depend at least in part on a type of connector component (e.g., a mechanical fastener, an adhesive, hook and loop material, etc.) that may be used. In one or more forms of the technology, a connection member may include one of the exemplary retainers 3700-1, 3750-1, 3700-2, 3700-3, 3700-4, 3700-5, 3700-6 or exemplary clips 3800-1, 3800-2, 3800-3, 3800-4, 3800-5, 3800-6 described herein. [0288] The configuration of a connection point may depend, at least in part, on the other components incorporated in a patient interface, which in turn, may depend, at least in part, on a manner in which air is delivered to a patient (a manner in which the patient is comfortable receiving the pressurized air). Air may be delivered to the patient in one of two main ways. In one example, the patient may receive the flow of pressurized air through tubes 3350, 3350-3 (see e.g., Fig. 3Y, 6F, 7, and 11). This may be referred to as a “tube up” configuration and may position a connection port at the top of the patient’s head. In other examples, the patient may receive the flow of pressurized air through a conduit connected to the plenum chamber 3200, for example through the connection port 3470 (see e.g., Fig. 3A and 3Y). This may be referred to as a “tube down” configuration where the airflow conduit is positioned in front of the patient’s face.

[0289] Different patients may be more comfortable with one style of air delivery over the other (e.g., because of the patient’s sleep style). Therefore, it may be beneficial to allow a single style of patient interface to be used in either the “tube up” or “tube down” configuration. Even with a single style, aspects of a connection point, such as a location, configuration, and what component provides the connection point, may differ as a result of a configuration of a plenum chamber and/or components attached thereto.

5.3.3.3.1 Conduit Sleeve

[0290] In some forms a sleeve 3351 that provides a connection point may be used with the tubes 3350 and/or the rigidiser arms 3340. The sleeve 3351 may at least partially surround the tubes 3350 and/or the rigidiser arms 3340. As shown in Figs. 6G and 6H, different shapes of sleeves 3351 may be used.

[0291] As shown in Fig. 6G, some forms of a conduit sleeve 3351 may include an inferior extension 3354. The inferior extension 3354 may be positioned on an opposite end of the conduit sleeve 3351 from a superior opening 3352 and define connection points 3356.

[0292] As shown in Fig. 6G, the inferior extension 3354 may include connection points 3356 where a connection member, such as a retainer of a headgear connector, may be located. As previously discussed, a connection member may be one of several types of connector components (e.g., a mechanical fastener, an adhesive, hook and loop material, etc.). The connection point 3356 may be located at an end of the inferior extension 3354, although the connection point 3356 could alternatively be positioned in a different location along the inferior extension 3354. The sleeve 3351 may be customized to fit a particular user’s face. For instance, the inferior extension 3354 of the sleeve 3351 may be configured in a relatively more posterior region or anterior region of the patient’s head.

[0293] In some forms, the conduit sleeve 3351 provides additional connection locations for connecting, for example, the four-point headgear 3302-1 (although, other forms of connectors aside from or in addition to the conduit sleeve 3351 may be used). For example, at the connection points 3356, the inferior straps 3304-1 may removably connect to the conduit sleeves 3351 (e.g., via headgear connectors 3600-1, 3650-1, 3600-2, 3600-3, 3600-4, 3600-5, 3600-6). In use, each inferior strap 3304-1 may contact the patient’s cheek (e.g., overlaying the masseter muscle). The inferior straps 3304-1 may also extend below the patient’s ears.

[0294] In some forms, a conduit sleeve 3351 may be used with the tubes 3350 in order to enable a patient to experience a “tube up” air delivery style with the mouth and nose cushion 3050-1. More specifically, in some forms, the conduit sleeve 3351 may include the superior opening 3352 disposed at one end of the conduit sleeve 3351. The superior opening 3352 may be an opening to a passage that extends along at least a portion of the conduit sleeve 3351. In the illustrated example, the conduit sleeves 3351, via superior openings 3352, may be connected to the tubes 3350 of the positioning and stabilising structure 3300 as shown in Fig. 6H.

5.3.3.3.2 Conduit Connectors

[0295] Fig. 7A shows a patient interface 3000-3 including conduit connectors 3500 that provide connection points 3356-3 where headgear connectors 3600-2 are incorporated for operatively connecting inferior straps 3304-3 to a plenum chamber 3200-3/seal-forming structure.

[0296] The conduit connectors 3500, like the conduit sleeves 3351 of the patient interface 3000-1 of Fig. 6H, connect the tubes 3350 to the plenum chamber 3200-3 to provide a flow of pressurized air to the plenum chamber 3200-3. The conduit connectors 3500 may provide other functions such as venting of a patient interface, asphyxia prevention by inclusion of an anti-asphyxia valve 3525, and connection to the positioning and stabilising structure 3300.

[0297] With respect to the positioning and stabilising structure 3300, the conduit connectors 3500 may be formed with a flange 3550. The flange 3550 may be moulded in one piece with the conduit connector 3500. Similar to the inferior extension 3354 of the patient interface 3000-1 of Fig. 6H, the flange 3550 may define or otherwise provide the connection points 3356 wherein a retainer (e.g., one of retainers 3700-1, 3750-1, 3700-2, 3700-3, 3700-4, 3700-5, 3700-6) of a headgear connector (e.g., one of headgear connectors 3600-1, 3650-1, 3600-2, 3600-3, 3600-4, 3600-5, 3600-6) is located. The connection point 3356 may include a female or male engagement structure (not shown) that may be (1) formed on or otherwise provided by the flange 3550, and (2) configured to be releasably engaged by another male or female engagement structure (e.g., third engagement structure 7004 of Figs. 7B, 8, and 9D) of the retainer 3700-1.

[0298] As noted above, the conduit sleeves 3351 and conduit connectors 3500 may provide connection points 3356 where a retainer, such as one of the exemplary retainers 3700-1, 3750-1, 3700-2, 3700-3, 3700-4, 3700-5, 3700-6 shown in Figs. 7A, 7Q, 8, 9B, 10A, 11B, and 12A, may be incorporated. As described in more detail below, a retainer according to one or more forms of the present technology may be configured to connect to (or have connected thereto) a corresponding clip, such as one of the exemplary clips 3800-1, 3800-2, 3800-3, 3800-4, 3800-5, 3800-6 shown in Figs. 7A, 8, 9F, 10C, 11B, and 12A, that may be integrated with the four-point headgear 3302-1 shown in Fig. 6E, the two-point headgear 3302-2 shown in Fig. 6F, or other suitable headgear. Although the disclosure describes a retainer incorporated at connection point 3356 and a clip integrated with the headgear for ease of explanation, it is contemplated that the retainer and clip (i.e., the engaging portions) of the headgear connector may be located in opposite orientations, so long as they are configured to engage with one another to secure the patient interface to the patient.

5.3.3.4 Headgear Connectors

[0299] When wearing a patient interface, a seal is formed between the seal forming structure and a region of the patient's face adjacent the patient's airways. When pressurized air is flowed through the patient interface, the seal forming structure tends to push away from the patient’s face. To counteract this tendency, an opposite force is applied to the seal forming structure to assist in maintaining its position with respect the patient's face. In addition to maintaining a suitable seal with the patient’s face, patients may also desire a patient interface that is easily removable. Further, a patient interface that integrates a structure configured to stabilise and maintain sufficient force with an air delivery conduit may reduce the complexity of securing the patient interface to a patient such that patient compliance with therapy is increased.

[0300] Headgear connectors described herein may provide an alternative to connectors that utilize magnets, or more generally magnetism, to provide secure attachments between components of seal-forming structures (e.g., a frame, a plenum changer) and headgear components (e.g., a strap such as an inferior strap). More specifically, absent magnets, magnetic components, or otherwise relying on magnetism, exemplary headgear connectors according to the present disclosure are configured to one or more of maintain a required seal with a patient’s face, facilitate attachment and removal of the patient interface, and inhibit unintended loosening or detachment of the patient interface from the patient’s face.

[0301] One of ordinary skill in the art will recognize that various components (e.g., retainers, clips, engagement structures, receivers) of headgear connectors according the present technology may, in some forms, be made, at least in part, from materials (e.g., metals, metallic composite materials) that may be responsive (e.g., attracted) to the magnetic properties of another object, and still be considered as not including magnets, magnetic components, or otherwise relying on magnetism to provide secure attachments as previously discussed. Furthermore, in some forms, various components (e.g., retainers, clips, engagement structures, receivers) of the exemplary headgear connectors of the present technology may be formed from materials that have magnetic properties/characteristics in such amounts that do not render the component as a whole to exhibit such magnetic properties, and still be considered as not including magnets, magnetic components, or otherwise relying on magnetism to provide secure attachments as previously discussed. Further, although the various components of headgear connectors described herein may be described as an alternative to magnetic headgear connectors, it is contemplated that headgear connectors of the present technology may optionally include magnetic materials and thus may employ both mechanical and magnetic fastening mechanisms.

[0302] As a result, the headgear connectors according to the present technology may be available to a wider range of patients, including those patients for whom having magnets located on or near one’s face may be less than desirable.

[0303] As shown in Figs. 7A-12B, different headgear connectors 3600-1, 3650-1, 3600-2, 3600-3, 3600-4, 3600-5, 3600-6 according to one or more forms of the present technology may be incorporated into various patient interfaces 3000-3, 3000- 4, 3000-5 or other suitable patient interfaces according to one or more forms of the present technology.

5.3.3.4.1 Lever and Bearing Surface Mechanism

[0304] Fig. 7A shows the patient interface 3000-3 including a headgear connector 3600-1 in accordance with one form of the present technology. Figs. 7B, 7C, and 7D respectively show overhead, side, and bottom perspective views of a retainer 3700-1 of the headgear connector 3600-1 in accordance with one form of the present technology. Figs. 7E, 7F, and 7G respectively show overhead, bottom, and side perspective views of a clip 3800-1 of the headgear connector 3600-1 in accordance with one form of the present technology. As described in more detail below, the clip 3800-1 is configured to engage and be secured to the retainer 3700-1 according to a type of engagement that may be mechanical and in some aspects may be void of any magnetic components. As is shown in Fig. 7 A, clip 3800-1 may include text or other indicia (e.g., texturing, color-coding, symbols, or other visual indicia or combinations thereof) to indicate to a user the type of headgear connector 3600-1 being used with patient interface 3000-3. For example, as shown in Fig. 7A, the text indicates that the connector 3600-1 is a non-magnetic connector 3600-1. Alternatively, the connector 3600-1 may include indicia that indicate that connector 3600-1 is a magnetic connector. Such indicia may allow a user to know whether the patient interface is suitable for use by the user. Further, it may help a user keep track of the type of connector 3600-1 currently connected to patient interface 3000-3. For example, in the scenario in which a user has changed the type of connector 3600-1 attached to patient interface 3000-3, the indicia may help the user to keep track of what type of connector 3600-1 is currently on the patient interface 3000-3. Lastly, while the indicia in Fig. 7 A is shown on the outer rim of clip 3800-1, the indicia may also or alternatively be located on another portion of clip 3800-1 or on retainer 3700-1.

[0305] As shown in Fig. 7B, the retainer 3700-1 includes a base wall 7008, a first engagement structure 7010, and a post 7030 extending from a base surface 7008A of the base wall 7008. In one form, the base wall 7008 may be adjacent to a flex wall 7006 which is adjacent to a frame 7004 on which a tab surface 7002 is provided. In one example, the frame 7004 may define an accommodation space 7004B and an aperture 7004 A, and thereby provide an interface engagement structure described in more detail below with reference to Fig. 7K.

[0306] The first engagement structure 7010 may include the base surface 7008A, an extension wall 7012 extending from the base surface 7008A, and a plurality of prongs 7020 extending from the extension wall 7012. The post 7030 may be part of a male engagement structure including the extension wall 7012 and the prongs 7020. Each prong 7020 may include: a riser 7022 extending from the extension wall 7012; an outwardly protruding ridge 7024 on a side facing away from the post 7030; and an inclined surface 7026 extending from the ridge 7024. As shown in Fig. 7B, the post 7030, the extension wall 7012, and the base surface 7008A may be arranged concentrically relative to one another. In some exemplary forms of the first engagement structure 7010 of the present technology, the prongs 7020, and more specifically risers 7022, may extend from the base surface 7008A such that there is no extension wall 7012 or there is a shorter extension wall 7012.

[0307] As shown in Figs. 7C and 7D, the base wall 7008 may define a recess or aperture 7040. The aperture 7040 may extend as a bore 7042 formed within the post 7030, as shown in Fig. 7K. With the inclusion of the bore 7042, less material may be used to construct the retainer 3700-1, making the retainer 3700-1 lighter than if constructed without the bore 7042. Alternatively, base wall 7008 may not define an aperture, and post 7030 may be solid rather than hollow. In another aspect, base wall 7008A may define a recess, and post 7030 may be solid rather than hollow.

[0308] In some forms of the present technology, the first engagement structure 7010 may include four prongs 7020 equally spaced around the post 7030, as is shown in Figs. 7H-7J. However, one of ordinary skill will appreciate that the first engagement structure 7010 may include different numbers of prongs 7020 in differing arrangements, for example, two, three, five, or more prongs 7020. In other forms, the prongs 7020 may be provided by a single cylindrical wall that extends from the extension wall 7012 and includes a riser 7022, ridge 7024, and inclined surface 7026. The implemented arrangement of the first engagement structure 7010 may correspond to an arrangement of a receiver 7520 located on the clip 3800-1, an exemplary version of which is illustrated in Figs. 7E-7G. Along with a connecting wall 7506 and an end face 7508 (see e.g., Fig. 7F), the receiver 7520 defines a second engagement structure 7510 located on the clip 3800-1.

[0309] As shown in Fig. 7E, the clip 3800-1 includes the receiver 7520, which defines an opening 7530 disposed between a proximal surface 7500A and an intermediate wall of the clip 3800-1. Opening 7530 is configured to receive at least a portion of the first engagement structure 7010 therein to mate the clip 3800-1 and the retainer 3700-1 with one another. In one form of the present technology, the receiver 7520 is comprised of: a first surface 7522; a second surface 7524; and a receiver transition 7528 formed or otherwise disposed between the first and second surfaces 7522, 7524 (see e.g., Fig. 7K). An opening 7530 may be defined by the receiver 7520 and the second body 7500 of the clip 3800-1. A portion of the receiver 7520 including the first surface 7522 may be inclined so as to form a conical or converging structure. A portion of the receiver 7520 including the second surface 7524 may be configured to surround the inclined surfaces 7026 of the prongs 7020 upon an engagement between the ridges 7024 of the prongs 7020 and a protruding edge of the receiver transition 7528 of the receiver 7520.

[0310] As shown in Figs. 7F and 7G, the connecting wall 7506 may extend from the proximal surface 7500A to the opening 7530 in the clip 3800-1. The connecting wall 7506, along with a third surface 7526 of the receiver 7520, may surround the opening 7530. The third surface 7526 may be provided on an opposite side of the opening 7530 than the connecting wall 7506. Although third surface 7526 is depicted in this embodiment, it may not be included depending on how clip 3800-1 is formed. For example, the space surrounding third surface 7526 may be filled in depending on how the body of the clip 3800-1 is formed.

[0311] An alternative version of the proximal surface 7500A is depicted in Figs.

7U to 7W. In this version, proximal surface 7500A may protrude inwards, towards opening 7530, before extending away from the outer or upper surface of clip 3800-1 shown in FIG. 7A. In this way, proximal surface 7500A may form a lip 7580 overhanging a ridge 7585, which may allow a finger of a user to more easily engage the proximal surface 7500A to lift the proximal portion of clip 3800-1 upwards and off of retainer 3700-1 to release the clip 3800-1 from retainer 3700-1, e.g., to remove patient interface 3000-3. In other aspects, the formation of the lip 7580 and ridge 7585 on the proximal surface 7500A may also indicate to a user the correct orientation of clip 3800-1. Because the lip 7580 and ridge 7585 allow a user to more easily release clip 3800-1 from retainer 3700-1, it may be more intuitive to a user to position clip 3800-1 over retainer 3700-1 so that the lip 7580 of proximal surface 7500A is furthest away from body 7000-1 of the retainer 3700-1, with the ridge 7585 positioned relatively closer to the body 7000-1, as shown in Fig. 7Z. Further, the protruding lip 7580 may provide a point of contact for a user to push down on to secure the clip 3800-1 to retainer 3700-1. This may inhibit users from positioning clip 3800-1 upside-down on retainer 3700-1. [0312] As is shown in Figs. 7X and 7Y, ridge 7585 may extend uniformly around the proximal and side portions of clip 3800-1 (Fig. 7Y) or may extend at an angle on each side portion of clip 3800-1 (Fig. 7X). For example, ridge 7585 may reach its lowest point at a proximal-most end of clip 3800-1 and may extend upwards as it wraps around the sides of clip 3800-1. If ridge 7585 extends substantially uniformly around the proximal and side portions of clip 3800-1, then lip 7580 may have a substantially similar thickness throughout. If ridge 7585 extends at an angle as it wraps around the sides of clip 3800-1, then lip 7580 may have a thickness that is greater at its proximal-most extent than it is at its distal-most extent along the sides of clip 3800-1.

[0313] In the illustrated example, the prongs 7020 of retainer 3700- 1 are formed or otherwise provided with the ridges 7024, and the receiver 7520 of clip 3800-1 is formed or otherwise provided with the receiver transition 7528 including a protruding edge in the form of a ridge. The outwardly protruding ridges 7024 of the prongs 7020 encircling the post 7030 of retainer 3700-1 may form an imaginary circle having a diameter that is greater than a diameter of the opening 7530 of clip 3800-1 at the receiver transition 7528. In other forms of the present technology, a protruding feature of the prongs 7020 may instead be provided as a protrusion with a shape such as a bump, and the receiver transition 7528 may provide the protruding edge as mentioned above and shown in Fig. 7K. Alternatively, the receiver transition 7528 may include a series of recesses shaped in accordance with a contour of the protrusions (e.g., bumps) protruding from the prongs 7020. Accordingly, in the context of the first and second engagement structures described throughout the present disclosure, a protrusion, such as a bump, may be used or otherwise provided instead of a ridge or protruding edge(s) (or vice versa), and one or more recesses may be used or otherwise provided instead of a groove (or vice versa).

[0314] Further, when describing two engaging structures (e.g., clip 3800-1 and receiver retainer 3700-1), ridges, slopes, dimples, protrusions, or other features on one structure (e.g., prongs 7020) may be interchangeable with ridges, slopes, dimples, protrusions, or other features on the opposite structure (e.g., receiver 7520). In combinations of engaging structures described herein that include one protruding structural element (e.g., ridge, edge, prong, etc.) and a recessed or otherwise receiving structural element (e.g., a recess, receiving space, slot, etc.), these structural elements may be reversed. More specifically, a first component (e.g., a retainer) that includes a protruding structural element may be provided in a form including a corresponding receiving structural element. It follows that, a second component (e.g., a clip) that includes a receiving structural element corresponding to the protruding structural element of the first component, may be provided in a form including the corresponding protruding structural element.

[0315] Figs. 7H-7J show the headgear connector 3600-1 in multiple states of engagement in accordance with one form of the present technology. More specifically, Fig. 7H illustrates a disengaged state of the headgear connector 3600-1 wherein the clip 3800-1 is positioned over the retainer 3700-1. In one example, Fig. 7H illustrates the clip 3800-1 in an exemplary position relative to the retainer 3700-1 such that the second engagement structure 7510 is ready for engagement with the first engagement structure 7010. In one example, this may include the post 7030 being in substantially spatial alignment with a central region of the opening 7530. With this alignment, the clip 3800-1 may be moved toward the retainer 3700-1 and into a position corresponding to the first partially engaged state shown in Fig. 71.

[0316] Fig. 7H illustrates one aspect of a level of usability provided by the exemplary headgear connector 3600-1 of Figs. 7A-7P. More specifically, in attempting to attach the clip 3800-1 to the retainer 3700-1, a patient may use the same hand to hold the clip 3800-1 and locate the retainer 3700-1 and engagement structure thereof. That is, a patient may use a finger that is not touching the clip 3800-1 to search for and locate the prongs 7020 or the post 7030 of the retainer 3700-1 without significant effort. Furthermore, the patient may use the prongs 7020 or the post 7030 to guide a movement of the clip 3800-1 toward the retainer 3700-1 generally, and engagement therewith specifically.

[0317] The capability of a patient to use one hand to perform the actions mentioned above may be attributed to both the prongs 7020 and the post 7030 having readily recognizable shapes and elevated positions relative to the remainder of the retainer 3700-1 and a seal forming structure of a patient interface, such as patient interface 3000-3 (or other suitable patient interface), to which the retainer 3700-1 may be attached. In addition, the exposed surface 7032 of the post 7030 may be formed with one or more structural elements, such as dimples, bumps, grooves, recesses, serrations, ridges, knurling, texturing, and the like, to enhance a distinctiveness of a feeling of touching the post 7030. One or more of these structural elements may additionally or alternatively be incorporated on other portions of retainer 3700-1, such as the first body 7000. For example, Figs. 7A and 7B depict bumps on first body 7000. The clip 3800-1 may additionally or alternatively include one or more structural elements as well, which may be different or the same as those incorporated on retainer 3700-1. Accordingly, some patients who may experience difficulty gripping objects because of dexterity issues, may be accommodated. That is these patients may also be able to implement an operation of engaging the clip 3800-1 to the retainer 3700-1 with one hand without too much difficulty since the patients will be able to recognize the distinct surfaces of the prongs 7020 and/or the post 7030. A shape of one or more of the connecting wall 7506, the end face 7508, and the first surface 7522 may also facilitate mating of the clip 3800-1 to the retainer 3700-1. For example, these structures may create a widened entrance to opening 7530 that tapers or otherwise narrows inward to assist with orienting the prongs 7020 within opening 7530. While these features may facilitate one-handed use, two-handed use is also contemplated. [0318] Fig. 71 shows the headgear connector 3600-1 in a partially engaged state. Prongs 7020 may be formed of a material that allows for deflection of the prongs 7020 towards and away from post 7030. In some aspects, the prongs 7020 may be spaced apart from the post 7030. If a force is applied to the prongs 7020, they may deflect inwards towards the post 7030. Once the force is removed, the prongs 7020 may return to their original position. For example, during engagement of the clip 3800-1 with the retainer 3700-1, the prongs 7020 may deflect inwards as they mate with opening 7530, e.g., as inwardly projecting portions of the receiver 7520 move past outwardly projecting portions of the prongs 7020 to engage with the retainer 3700-1. The deflectability of the prongs 7020 may facilitate engagement of the clip 3800-1 with the retainer 3700-1 and/or securing of the clip 3800-1 with the retainer 3700-1. In the position illustrated in Fig. 71, the ridges 7024 of the prongs 7020 may be engaged with the receiver transition 7528. In one example, the partially engaged state may correspond a point in an engagement process just before or as the prongs 7020 start to contract towards the post 7030.

[0319] As one of ordinary skill will recognize, until the receiver transition 7528 is moved below the ridges 7024 of the prongs 7020, the inward deflection of the prongs 7020 may continue with the movement of the clip 3800-1 toward the base surface 7008A of the retainer 3700-1. However, as the receiver transition 7528 comes into fitting engagement with bases of the ridges 7024 (as shown in Fig. 7K), a material bias of the prongs 7020 may cause the prongs 7020 to flare outward, returning to their original position. As a result, the ridges 7024 of the prongs 7020 may be securely positioned within the receiver 7520 above the receiver transition 7528, and the clip 3800-1 may be securely attached to the retainer 3700-1 as shown in Fig. 7J.

[0320] Figs. 71 and 7J also demonstrate some additional exemplary aspects of usability that may be attributable to the exemplary headgear connector 3600-1. In particular, engagement between the first and second engagement structures 7010, 7510 may be effected by movement of the clip 3800-1 toward the base surface 7008A of the retainer 3700-1. Further, the angle of the first surface 7522 of the receiver 7520 of the clip 3800-1 may allow for some deviation from a central region of the post 7030 and a central region of the opening 7530 being in complete alignment, without hindering a patient’s ability to progress from the disengaged state show in Fig. 7H to the partially engaged state shown in Fig. 71 and from the partially engaged state shown in Fig. 71 to the engaged state shown in Fig. 7 J. In particular, as contact is made with the prongs 7020, the incline of the first surface 7522 of the receiver 7520 may direct movement of the clip 3800-1 into sufficient alignment for receiver transition 7528 to engage the prongs 7020.

[0321] As noted above, the exemplary opening 7530 and exemplary prongs 7020 may help facilitate engagement in situations where there is less than perfect alignment between the central regions of the post 7030 and the opening 7530. As illustrated, the opening 7530 is provided with a circular configuration, and the prongs 7020 have a corresponding circular arrangement. However, one of ordinary skill in the art will recognize that other shapes may be used as a basis for the designs of engaging components of the headgear connector 3600-1. Such flexibility may be enabled, in part, by the inclined configuration of the first surface 7522. The receiver 7520 may provide a female engagement structure for the headgear connector 3600-1 that may be incorporated in the second engagement structure 7510 of the clip 3800-1 (as shown), or in the first engagement structure 7010 of the retainer 3700-1. In the case of the former, the first surface 7522 of the receiver 7520 may guide a movement of the clip 3800-1 against and relative to the prongs 7020. In the case of the latter, the angle of the first surface 7522 may guide a movement of clip 3800-1 by acting as a funnel and directing movement of the prongs 7020 relative to the receiver 7520 incorporated in the retainer 3700-1 and toward the receiver transition 7528 thereof.

[0322] The retainer 3700-1 and the clip 3800-1 may be formed with different materials or may be formed of the same materials. Additionally, different portions of the retainer 3700-1 and the clip 3800-1 may be formed of the same or different materials.

[0323] The retainer 3700-1 may be formed from a plastic, e.g., a thermoplastic polyester elastomer (TPE), material having a stiffness that is less than that of the clip 3800-1. In some forms, the retainer 3700-1 may be formed from TPE such as HYTREL (included in the range of products sold under this trademark, such as Hytrel 7246), manufactured by DuPont. In other forms, the retainer 3700-1 more generally may be formed from materials having particular mechanical properties such as a tensile modulus of about 525 MPa, a flexural modulus of about 550 MPa, and a nominal Shore D hardness of about 72D. Any of the other exemplary retainers 3750- 1, 3700-2, 3700-3, 3700-4, 3700-5, 3700-6 described may be formed from the materials identified above or from materials having the material properties identified above.

[0324] In one example, the clip 3800-1 may be formed of a plastic material, e.g., a thermoplastic polymer material, such as a polycarbonate material. In some forms, the clip 3800-1 may be formed from a polycarbonate material such as MAKROLON (included in the range of products sold under this trademark, such as Makrolon 2458), manufactured by Bayer Material Science. In other forms, the clip 3800-1 more generally may be formed from materials having particular mechanical properties such as a tensile modulus of about 2400 MPa, a flexural modulus of about 2350 MPa, and a ball indentation hardness of about 115 N/mm². Any of the other exemplary clips 3800-2, 3800-3, 3800-4, 3800-5, 3800-6 described herein, may be formed from the materials identified above or from materials having the material properties identified above.

[0325] Fig. 7J illustrates an engaged state for the headgear connector 3600-1. In the illustrated example, the opening 7530 is substantially circular and the ridges 7024 combine to outline a shape corresponding to a circular perimeter. As such, engagement between the ridges 7024 and the receiver transition 7528 may be characterized as an annular snapping mechanism. However, it will be understood by those of ordinary skill that other shapes may provide a template for the configurations of the prongs 7020 and the receiver 7520.

[0326] A force required to effect the action depicted in Figs. 7H-7J, and particularly movement from the partially engaged state of Fig. 7H to the engaged state of Fig. 7J, may be less than about 40. ON, less than about 35.0N, less than about 30.0N, less than about 25.ON, less than about 20.0N, less than about 15.0N, less than about 10. ON, or less than about 5. ON. For example, a fitting force may be about 1.0N to about 10.0N, about 5.0N to about 10. ON, about 1.0N to about 15.0 N, or about 1.0N to about 30.0N. These force characteristics for engagement between portions of a headgear connector may be generally applicable to other exemplary headgear connectors of the present technology, including, e.g., the headgear connectors 3650-1, 3600-2, 3600-3, 3600-4, and 3600-5, described hereafter.

[0327] A force required to remove or disconnect the clip 3800-1 from the retainer 3700-1 (i.e., to move from Fig. 7J to Figs. 71 and 7H) may be less than about 60. ON, less than about 55. ON, less than about 50. ON, less than about 45.0N, less than about 40.0N, less than about 35.0N, less than about 30.0N, less than about 25.0N, less than about 20. ON, less than about 10. ON, or less than about 5. ON. For example, a removal force may be about 1.0N to about 60. ON, about 5. ON to about 50.0N, about 5. ON to about 45. ON, about 5. ON to about 40. ON, about 5. ON to about 35. ON, about 5. ON to about 30. ON, about 5. ON to about 25. ON, about 5. ON to about 20. ON, about 5. ON to about 15. ON, or about 5. ON to about 10. ON. These force characteristics for removal/disengagement between portions of a headgear connector may be generally applicable to other exemplary headgear connectors of the present technology, including, e.g., the headgear connectors 3650-1, 3600-2, 3600-3, 3600-4, and 3600-5 described hereafter.

[0328] Further with respect to usability, engagement or disengagement of the clip 3800-1 and the retainer 3700-1 may be indicated by feedback that signals to a patient that the clip 3800-1 and the retainer 3700-1 are engaged, disengaged, or both. For example, in moving the clip 3800-1 from the first partially engaged state shown in Fig. 71 to the exemplary engaged state of Fig. 7J, the prongs 7020 may be snapped into a position above the receiver transition 7528 and within a portion of the opening 7530 surrounded by the second surface 7524. This may result in one or both of auditory and haptic feedback to the patient. Snapping the prongs 7020 into a position within the space surrounded by the second surface 7524 may create a snapping sound that can serve as notice that an engagement has been accomplished. As far as haptic feedback, the patient may feel the overcoming of a resistive force applied by the receiver transition 7528 on the inclined surfaces 7026 and ridges 7024 of the prongs 7020 and residual movement of prongs 7020 as a result, or a vibration caused by the same. Additionally, or alternatively, the patient may feel the impact of the connecting wall 7506 and/or the first end face 7508 being positioned on the base surface 7008A as shown in Fig. 7K. The reverse interactions may similarly provide one or both of auditory and haptic feedback when disengaging clip 3800-1 and the retainer 3700-1. [0329] Fig. 7K shows a cross-sectional view of the headgear connector 3600-1 from a plane corresponding to line 7K-7K from Fig. 7J, looking in a direction K as indicated in Fig. 7J. As shown in Fig. 7K, in the engaged state, the receiver transition 7528 is engaged with bases of the ridges 7024 of the prongs 7020. Further, the inclined surfaces 7026 of the prongs 7020 are encircled by the second surface 7524 of the receiver 7520. On the other hand, the extension wall 7012 and the risers 7022 may be encircled by the first surface 7522 of the receiver 7520 in the exemplary engaged state depicted in Fig. 7K. As shown in Fig. 7K, in some forms of the present technology, the connecting wall 7506 and a first end face 7508 of the receiver may contact the base surface 7008A of the retainer 3700-1.

[0330] With further reference to Fig. 7K, the first body 7000 of the retainer 3700- 1 defines the base wall 7008, the flex wall 7006, and the frame 7004. The base wall 7008 defines a portion of the first body 7000 that supports the first engagement structure 7010 as well as an area that may be gripped by an individual when attaching or detaching the retainer 3700-1 to and from a patient interface (in embodiments in which retainer 3700-1 is detachable from the patient interface), such as the patient interface 3000-1 shown in Fig. 7. The flex wall 7006 may have a reduced thickness relative to the base wall 7008, and may act as a bridge between the base wall 7008 and the frame 7004. The frame 7004 defines an interface engagement structure and includes features that enable the retainer 3700-1 to be attached to the patient interface 3000-1.

[0331] In some forms, the reduced thickness of the flex wall 7006 may enable some elastic movement of the base wall 7008 relative to the frame 7004. In one example, the flex wall 7006 may bend when a force is applied to the base wall 7008 and the frame 7004 is held stationary or vice versa. As a result, the retainer 3700-1 may flex (e.g., bend) or otherwise elastically deform during one or more of, e.g.: when the retainer 3700-1 is attached or detached from the patient interface 3000-1; when the clip 3800-1 is attached or detached from the retainer 3700-1; and to accommodate patient movement when the patient interface 3000-3, for example, is being worn.

[0332] A proximal end of the retainer 3700-1 defines a leading wall of the frame 7004 that extends from and joins a wall on which the tab surface 7002 is defined. A support wall may extend from a portion of the proximal wall adjacent to the flex wall 7006 to the proximal end and thereby close the frame 7004. The support wall may define an engagement component of the frame 7004. In one example, the support wall may define an aperture 7004A, which may provide, and thus define the interface engagement structure provided by the frame 7004 as, a female engagement structure. More specifically, the aperture 7004A may be configured to receive a male engagement structure included on a seal forming structure or component attached thereto. In one example, the male engagement structure may be received through the aperture 7004 A into an accommodation space 7004B in the frame 7004 shown in Fig. 7K.

[0333] As shown in Fig. 7K, a height of the frame 7004 may be greater than the thickness of the base wall 7008. Thus, the flex wall 7006 may be spaced from a surface of a component to which the frame 7004 is engaged. As a result, when attached to a patient interface, such as patient interface 3000-3, the frame 7004 may provide a fulcrum about which the flex wall 7006 and the base wall 7008 may move. For example, the frame 7004 may be attached to a patient interface, and the first engagement structure 7010 of the retainer 3700-1 may be engaged with (attached to) the second engagement structure 7510 of the clip 3800-1. In this example, application of a force to the clip 3800-1, for example in an upward or downward direction relative to an orientation of the clip 3800-1 in Fig. 7K, may cause the flex wall 7006 to bend or otherwise move. In turn, a combined movement of the base wall 7008 and the clip 3800-1, functioning as a lever, may result from the movement of the flex wall 7006 and the engagement between: (1) the prongs 7020 of the retainer 3700-1; and (2) the receivers 7520 of clip the 3800-1. [0334] In reference to the example illustrated in Fig. 7Z and as described above, clip 3800-1 may in some aspects include a lip 7580 that may provide a first upper or outer surface for a user to push down on when attaching clip 3800-1 to retainer 3700- 1. Lip 7580 and ridge 7585, if included, may further provide a second lower surface to which a user can apply force with a finger in order to push or pull clip 3800-1 away from retainer 3700-1 to release clip 3800-1 from retainer 3700-1.

[0335] In some aspects, one or more portions of retainer 3700-1 or clip 3800-1 (or both) may include features designed to make connector 3600-1 easier to clean or less likely to trap debris or germs. For example, Fig. 7AA depicts a bottom view of a clip 3800-1. Clip 3800-1 may be designed to omit overly narrowed portions or recesses that come to a point in order to inhibit debris or germs from accumulating in the narrowed portions or recesses. Narrowed portions and recesses may also be more difficult for a user to clean, and a user wiping these portions may be unable to effectively clean these portions on a regular basis. Fig. 7AA depicts one example of a design that may try to avoid the use of recesses that come to a narrow point. Location 7590 depicts a recess where second surface 7526 extending around opening 7530 meets a sidewall of clip 3800-1. Location 7590 may be shaped so that a narrow point is not formed in the recess between second surface 7526 and the sidewall of clip 3800-1. For example, location 7590 may be U-shaped at its proximal-most extent or may form a flat wall separating the sidewall and second surface 7526. While location 7590 may be relatively narrower than surrounding portions, avoiding a recess that comes to a narrow point may reduce the likelihood of debris or germs collecting at location 7590. Further, it may be easier for a user to clean location 7590 by wiping clip 3800-1 or submerging clip 3800-1 in a fluid. By creating a gap between the sidewall and second surface 7526 at location 7590, this version of clip 3800-1 may be easier to clean. In one example, location 7590 may have a gap width of at least .5 mm or of at least 1 mm at its narrowest point. For example, the gap width may be about 1 mm to about 2 mm, about 1 mm to about 1.5 mm, or about 1 mm to about 1.3 mm.

[0336] Various headgear connectors described herein, including the headgear connectors 3600-1, 3650-1, 3600-2, 3600-3, 3600-4, 3600-5, 3600-6 of Figs. 7A-12B, may offer favourable levels of usability and comfort, particularly with respect to placing a patient interface on a patient and subsequently, in maintaining the patient interface in a secure, seal maintaining, and appropriate position. In addition, the headgear connectors described herein may offer patients flexibility in choosing between different types of masks and headgear connectors without having to sacrifice these favourable levels of usability and comfort.

[0337] More specifically, the headgear connectors 3600-1 and headgear connectors 3650-1, 3600-2, 3600-3, 3600-4, 3600-5, 3600-6 described hereafter, in particular, may include the frame 7004 as an interface engagement structure. As a result, the headgear connectors 3600-1, 3650-1, 3600-2, 3600-3, 3600-4, 3600-5, 3600-6 may be retrofitted to existing models of patient interfaces that include male engagement structures for retainers that are compatible with the female interface engagement structure version of the frame 7004 (see, e.g., Figs. 7B-7D, 7K, 7Z, 8, and 9B-9D). Alternatively, the headgear connectors 3600-1, 3650-1, 3600-2, 3600-3, 3600-4, 3600-5, 3600-6 may incorporate versions of the interface engagement structure that include a male engagement structures as previously mentioned. As a result, these versions of the headgear connectors 3600-1, 3650-1, 3600-2, 3600-3, 3600-4, 3600-5, 3600-6 may be retrofitted to existing models of patient interfaces that include female engagement structures for retainers that are compatible with the male interface engagement structure version of the frame 7004. Accordingly, the headgear connectors 3600-1, 3650-1, 3600-2, 3600-3, 3600-4, 3600-5, 3600-6 may be readily used to replace magnetic headgear connectors with retainers that utilize the frame 7004 as an interface engagement structure.

[0338] Alternatively, the retainers according the present technology, such as the exemplary retainers 3700-1, 3750-1, 3700-2, 3700-3, 3700-4, 3700-5, 3700-6 of Figs. 7A-12B, may incorporate different types of interface engagement structures that are compatible with various engagement structures included on different types of patient interfaces. For example, certain aspects of retainers for “tube up” patient interfaces may differ in shape, size, and type of interface engagement structure as compared to retainers for “tube down” type of patient interfaces. However, the retainers may include the same or similar engagement structure (e.g., the male engagement structure) and be used with clip 3800-1, 3800-2, 3800-3, 3800-4, 3800-5, 3800-6 to provide headgear connectors that may be used to replace headgear connectors currently in use, such as those including magnetic components.

[0339] As discussed above, conduit connectors 3500 may be formed with the flange 3550 that may define or otherwise include a connection point 3356 for the retainer 3700-1 of the headgear connector 3600-1. In other aspects, however, the flange 3550 may be separate from conduit connector 3500 and may be present on patient interface 3000-3, for example, in order to serve as a connection point 3356, or connection point 3356 may be located somewhere other than on a flange. The connection point 3356 may include a female or male engagement structure (not shown) that may be configured to be releasably engaged by a corresponding male or female interface engagement structure, such as the interface engagement structure provided by the frame 7004 of the retainer 3700-1 in order to secure the retainer 3700-1 to the patient interface 3000-3. In other aspects, the retainer 3700-1 may be permanently coupled to connection point 3356, and in such an embodiment, connection point 3356 may not include a mating feature.

[0340] The configuration of both the first and second engagements structures 7010, 7510 may allow for some rotation of the clip 3800-1 relative to the retainer 3700-1. Such rotation may occur as a patient wears a patient interface, such as patient interface 3000-3, for example, while moving when awake and/or sleeping. Some movements by the patient that may cause this rotation may, if not accommodated by the relative rotation of the headgear connector 3600-1, cause certain tensile or other forces to be applied to the patient by one or more components of the patient interface 3000-3. In turn, the patient could experience varying degrees of discomfort if not for the limited rotation between the clip 3800-1 and the retainer 3700-1 allowed for by the headgear connector 3600-1 in accordance with the present technology. In some aspects, if relative rotation of the clip 3800-1 and the retainer 3700-1 is not permitted, then the forces applied during movements may cause the clip 3800-1 and the retainer 3700-1 to disengage, resulting in unintended loosening or falling off of the patient interface, which may interrupt the intended treatment from being provided. Thus, with the implementation of the headgear connectors 3600, such movements may go unnoticed or generally not be considered bothersome by the patient and/or may reduce the occurrence of unintentional loosening or removal of the patient interface.

[0341] Figs. 7L-7P show the headgear connector 3600-1 during use with a patient interface positioned on a patient in multiple states leading to the disengaged state, in accordance with one form of the present technology. Fig. 7L illustrates the headgear connector 3600-1 in the engaged state and identifies the post 7030 and exposed surface 7032 of the post 7030. Figs. 7M and 7N illustrate the exemplary headgear connector 3600-1 in the engaged state, and first and second fingers 1025, 1035 in an exemplary first hand position 1005A (Fig. 7M), 1005B (Fig. 7N). Fig. 70 shows the headgear connector 3600-1 in the process of disengaging, and Fig. 7P shows the headgear connector 3600-1 in the disengaged state.

[0342] According to some forms of the present technology, the prongs 7020 of headgear connector 3600-1 provide part of an annular snapping mechanism. That is the prongs 7020 may bend and contract inward during engagement with receiver transition 7528, and expand and establish a retention force once passed over by the receiver transition 7528. Successful implementation of the headgear connector 3600-1 may balance (1) exhibiting a retention force sufficient to withstand a patient’s movements during sleep and remain in the engaged state; and (2) not being so high so as to make intentional removal unduly difficult for the patient. The post 7030 may assist in striking this balance. The post 7030 may provide a patient with a bearing surface and a point of leverage that can be used to angle and push receiver transition 7528 of the clip 3800-1 away from (lever off of) the ridges 7024 of the prongs 7020 of the retainer 3700-1. Thus, the post 7030 may be used to provide a patient with a mechanical advantage and multiply a force the patient applies to oppose a retention force of the headgear connector 3600-1.

[0343] In some examples, engagement between the first and second engagement structures 7010, 7510 may exhibit a removal force corresponding to a force that must be applied by a patient to disengage the clip 3800-1 from the retainer 3700-1. As discussed above, a force required to disengage the clip 3800-1 from the retainer 3700- 1 (as is shown in Figs. 7L-7P) may be less than about 60. ON, less than about 55. ON, less than about 50. ON, less than about 45. ON, less than about 40.0N, less than about 35.0N, less than about 30.0N, less than about 25.0N, less than about 20. ON, less than about 10. ON, or less than about 5. ON. For example, a removal force may be about 1.0N to about 60.0N, about 5. ON to about 50.0N, about 5. ON to about 45. ON, about 5.0N to about 40.0N, about 5.0N to about 35.0N, about 5.0N to about 30. ON, about 5. ON to about 25. ON, about 5. ON to about 20.0N, about 5. ON to about 15. ON, or about 5.0N to about 10.0N.

[0344] In one example, the first finger 1025 is a thumb and the second finger 1035 is an index finger, although different fingers may be used by a patient. The exposed surface 7032 of the post 7030 may provide a patient with a bearing or contact point or surface against which the patient may press when detaching the clip 3800-1 from the retainer 3700-1. As shown in Fig. 7M, the patient may press the second finger 1035 against the post 7030 while using the first finger 1025 to apply a force to the clip 3800-1 in a direction away from the retainer 3700-1. Alternatively, as shown in Fig. 7N the patient may press the first finger 1025 against the post 7030 while using the second finger 1035 to apply a force to the clip 3800-1 in a direction away from the retainer 3700-1.

[0345] In the illustrated example in Fig. 7M, the force applied to the clip 3800-1 may be applied by the first finger 1025 in the first hand position 1005A to a side region or a proximal region of the clip 3800-1 in area adjacent to the proximal surface 7500A of the clip 3800-1. If clip 3800-1 includes a lip 7580, the first finger 1025 may engage and pull up on the lip 7580. In the illustrated example in Fig. 7N, the force may be applied by the second finger 1035 in the first hand position 1005B to the side region in an area adjacent to the crossbar 7504 of the clip 3800-1. However, it will be understood that the force may be applied, in either version of the first hand position 1005A, 1005B, to other portions of the clip 3800-1, such as the crossbar 7504, another section of a side region, or the proximal surface 7500A. Accordingly, the first finger 1025 or the second finger 1035 may apply a force on the proximal surface 7500A (e.g., lip 7580, if included), the crossbar 7504, or a side region, and thereby lever the clip 3800-1 off of the male engagement structure provided as the first engagement structure 7010 of the retainer 3700-1.

[0346] Alternatively, a patient may prefer to partially disengage the clip 3800-1 from the retainer 3700-1 and change to a second hand position 1060 as shown in Fig. 70. More specifically, a patient may prefer to use the finger used to press against the post 7030 for leverage, to grip another portion of the clip 3800-1 (e.g., lip 7580, if included) and move the clip 3800-1 away from the retainer 3700-1. An example of a result of this action is depicted in Fig. 7P, in which the headgear connector 3600-1 is in the disengaged state.

[0347] Due to the leverage provided by pressing against the post 7030, a patient may not have to apply such a force on the crossbar 7504 so as to cause the patient to strain or have difficulty disengaging and detaching the clip 3800-1 from the retainer 3700-1. Instead, the patient may perform the simple movement described above using two fingers to detach the clip from the retainer, release tension being applied by a headgear strap (see e.g., inferior strap 3304-1 in Figs. 6E and 6H), and take a patient interface, such as the patient interface 3000-3, off of the patient. Although two example hand positions are show for removal of the patient interface 3000-3 a patient may disengage clip 3800-1 from the retainer 3700-1 using any suitable fingers or motions.

[0348] Figs 7A-7P depict opening 7530 extending through an entire thickness of the clip 3800-1 so that the opening 7530 is visible on opposing surfaces of the clip 3800-1. Further, engagement and disengagement of the clip 3800-1 and the retainer 3700-1 are discussed above in terms of an exposed surface 7032 of the post 7030 projecting through the opening 7530 of the clip 3800-1. That said, it is contemplated that in some forms of the technology described herein, the opening 7530 may not extend completely through the clip 3800-1 such that when the clip 3800-1 and the retainer 3700-1 are engaged, the post 7030 is not visible and surface 7032 may be positioned within the clip 3800-1.

[0349] As noted above with respect to the ridges 7024 of the prongs 7020 and the protruding edge of the receiver transition 7528, various sub-structures providing male and female engagement structures responsible for engaging corresponding substructures may be provided in alternative forms. In addition, any of the first engagement structures for any of the exemplary retainers described herein may incorporate a female engagement structure. It then follows that any of the second engagement structures for any of the exemplary clips described herein may include a male engagement structure. Thus, in the case of the exemplary headgear connector 3600-1 illustrated in Figs. 7A-7P, a form of the receiver 7520 may be incorporated into the retainer 3700-1, and a form of the male engagement structure may be incorporated into the clip 3800-1. An example of such an alternative version of the headgear connector 3600-1 is described below.

[0350] More specifically, the retainer 3700-1 may include a form of the post 7030 and a form of the receiver 7520 extending from the base surface 7008A. On the other hand, a form of the opening 7530 defined by the second body 7500 of the clip 3800-1 may be surrounded by forms of the extension wall 7012 and the prongs 7020 extending from the second body 7500. In one example, engagement between the retainer 3700-1 and the clip 3800-1 may include: (1) aligning the opening 7530 with the post 7030; (2) the clip 3800-1 moving toward the retainer 3700-1; (3) the prongs 7020 incorporated in the clip 3800-1 engaging forms of the first surface 7522, receiver transition 7528, and second surface 7524 of the receiver 7520 incorporated in the retainer 3700-1; (4) the post 7030 extending through an area surrounded by the prongs 7020 (and extension wall 7012 if included) of the clip 3800-1; and (5) some portion of the prongs 7020 extending through the opening 7530.

[0351] Fig. 7Q shows a side perspective view of a retainer 3750-1 for a headgear connector 3650-1 (see, e.g., Figs. 7R-7T) in accordance with one form of the present technology. The retainer 3750-1 includes a first inclined surface defined by: (1) an extension wall 7012-1 and risers 7022-1 of prongs 7020-1, or (2) the risers 7022-1 alone where they extend to the base surface 7008A-1 (hereafter referred to as “first inclined surface 7012-1, 7022-1”). As discussed below, the first inclined surface 7012-1, 7022-1 may assist a patient in correctly attaching a clip 3800-1 to the retainer 3750-1 and inhibit incorrect attachment.

[0352] As shown, the retainer 3750-1 includes a base wall 7008-1, a first engagement structure 7010-1, and a post 7030 extending from a base surface 7008A-1 of the base wall 7008-1. The first engagement structure 7010-1 may include the base surface 7008A-1, the extension wall 7012-1 extending from the base surface 7008A- 1, a plurality of prongs 7020-1 extending from the extension wall 7012-1, and the post 7030. Each prong 7020-1 may include: the riser 7022-1 extending from the extension wall 7012-1; an outwardly protruding ridge 7024 on a side facing away from the post 7030; and a second inclined surface 7026 extending from the ridge 7024. In some exemplary forms of the first engagement structure 7010-1, the prongs 7020-1, and more specifically risers 7022-1, may extend from the base surface 7008A-1 such that there is no extension wall 7012-1 or there is a shorter extension wall 7012-1 than shown in Fig. 7Q.

[0353] As discussed above, the extension wall 7012-1 and the risers 7022-1, or the risers 7022-1 alone where they extend from the base surface 7008A-1, may define the first inclined surface 7012-1, 7022-1. In practice, the first inclined surface 7012-1, 7022-1 may be sized to have a height and angle of inclination to form a structure that prohibits a clip, such as clip 3800-1 depicted in Figs. 7R-7T, from being secured to the retainer 3750-1 upside down (i.e., with a connecting wall 7506 as shown in Fig. 7R facing away from the retainer 3750-1). This type of incorrect engagement prevention feature may be recognized by some as a “poka yoke” or a “mistake-proof’ feature. Such a feature may inhibit incorrect attachment of clip 3800-1, which may otherwise result in one or more of an unstable connection with the patient interface, improper fit, discomfort, leaking in the patient interface, difficultly unclipping the clip 3800-1, or other potential issues.

[0354] Figs. 7R-7T show portions of a headgear connector 3650-1 including a clip 3800-1 and the retainer 3750-1 of Fig. 7Q, in multiple states of engagement. Fig. 7R illustrates a disengaged state of the headgear connector 3650-1 wherein the clip 3800-1 may be in an exemplary position relative to the retainer 3750-1 ready for engagement there between. More specifically, the clip 3800-1 and retainer 3750-1 may be aligned such that a second engagement structure of the clip 3800-1, which may include a first surface 7522, a second surface 7526, and a receiver transition 7528, is positioned to engage the first engagement structure 7010-1 as the clip 3800-1 is moved toward the retainer 3750-1.

[0355] Turning to Fig. 7S, an initial engagement between the receiver transition 7528 and the ridges 7024 is depicted. As indicated by the arrows in Fig. 7S, the prongs 7020-1 are biased inward toward the post 7030 due to contact between the receiver transition 7528 and the ridges 7024, and continued movement of the clip 3800-1 downward toward the position illustrated in Fig. 7T. More specifically, as the receiver transition 7528 moves past the outward most projecting portions of the ridges 7024, the receiver transition 7528 will come into fitting engagement with bases of the ridges 7024 of the prongs 7020-1. As this occurs, a material bias of the prongs 7020-1 may cause the prongs 7020-1 to flare outward, as indicated by the arrows in Fig. 7T, returning to their original position. As a result, the ridges 7024 of the prongs 7020-1 may be securely positioned within the receiver 7520 above the receiver transition 7528, and the clip 3800-1 may be securely attached to the retainer 3750-1, as shown in Fig. 7T. As shown in Fig. 7T, the first surface 7522 of the clip 3800-1 may be in resting contact with the first inclined surface 7012-1, 7022-1 in the engaged state of the headgear connector 3650-1.

[0356] On the other hand, if the clip 3800-1 was positioned such that the connecting wall 7506 was facing an opposite direction than in Fig. 7R, , i.e., facing up away from receiver 3750-1, the configuration of the extension wall 7012-1 and the risers 7022-1 may prevent the receiver transition 7528 of the clip 3800-1 from moving past the ridges 7024 of the prongs 7020-1 of the retainer 3750-1. More specifically, with connecting wall 7506 facing upwards, the first inclined surface 7012-1, 7022-1 would prevent the receiver transition 7528 from moving past the ridges 7024. In some forms, this may result from contact between the second surface 7524 of the clip 3800- 1 and the first inclined surface 7012-1, 7022-1 or a top surface of the first inclined surface 7012-1, 7022-1. Such contact may not allow continued downward movement of an upside-down clip 3800-1 past a point where an inward-most projecting portion of the receiver transition 7528 is just above or even with outward-most projecting portion of the ridges 7024 of the prongs 7020-1, even if the prongs 7020-1 are in a fully contracted state (e.g., in contact with the post 7030).

[0357] Although the specific “poka yoke” mechanism of Figs. 7Q-7T is described herein, it is contemplated that other “poka yoke” features may be incorporated into the headgear connectors, either instead of or in combination with the “poka yoke” features depicted in Figs. 7Q-7T. Further, although the “poka yoke” is described in detail in reference to the headgear connector 3650-1, the same or other “poka yoke” features may be incorporated into, e.g., headgear connectors 3600-1, 3600-2, 3600-3, 3600-4, 3600-5, 3600-6 to promote correct orientation of the clip relative to the retainer.

[0358] Figs. 7R-7T also show details of a body 7000-1 of the retainer 3750-1 that may be incorporated in any of the retainers described herein. An inner surface of the body 7000-1 may define an aperture 7040-1 in the form of a cone shaped opening that transitions to a bore 7042-1 defined by an inner surface of the post 7030. A surface defining the aperture 7040-1 may transition into a cylindrical inner surface of the post 7030 defining the bore 7042-1, around a location corresponding to the extension wall 7012-1 or the risers 7022-1. This cored out configuration for the base wall 7008-1 and the post 7030 may prevent sink marks from developing on an outer surface of a plenum chamber defining wall when exposed to repeated use of the post 7030 for disengaging forms of clips from forms of retainers of the present technology. In other aspects, different shapes of aperture 7042-1 may be used, or no aperture 7042-1 may be used.

5.3.3.4.2 Lever Mechanism

[0359] Fig. 8 shows a perspective, transparency view of a headgear connector 3600-2 in an engaged state in accordance with one form of the present technology. The headgear connector 3600-2 may be incorporated in the exemplary patient interfaces described herein, such as patient interface 3000-1, 3000-3 (see e.g., Figs. 6H, 7A, 9A). As described in more detail below, the clip 3800-2 may be configured to engage and be secured to the retainer 3700-2 according to a type of engagement that may be mechanical and in some aspects may be void of any magnetic components.

[0360] As shown in Fig. 8, a retainer 3700-2 includes a first engagement structure 8010 that may include prongs 8020 extending from a base surface 8OO8A of a base wall 8008. Each prong 8020 may include a riser 8022 extending from the base surface 8OO8A, and an outwardly protruding ridge 8024 provided at an upper portion of the riser 8022, opposite base surface 8OO8A. Furthermore, by extending from the base surface 8OO8A, the prongs 8020 may define a male engagement structure.

[0361] A second body 8500 of the clip 3800-2 may define a female engagement structure between a crossbar 8504 and a proximal surface 8500A, and provide a second engagement structure. The second engagement structure may be configured to engage and snap onto the ridges 8024 of the prongs 8020. For example, the second engagement structure may include an opening that extends fully (e.g., through-bore) or partially through (e.g., blind bore) the second body 8500 of the clip 3800-2. The opening may be sized to snap fit around the prongs 8020. In some aspects, the opening may include an inwardly projecting ridge or lip configured to engage the risers 8022 of the prongs 8020 below the protruding ridges 8024 of the prongs 8020. This may facilitate engagement of the clip 3800-2 with the retainer 3700-2.

Accordingly, by being configured to receive the prongs 8020 and secure the clip 3800-2 onto the retainer 3700-2 by engagement with the ridges 8024, the clip may define a female engagement structure.

[0362] In some forms of the present technology, the male engagement structure incorporated with the first engagement structure 8010 may include four equally spaced prongs 8020. However, one of ordinary skill will appreciate that different numbers of prongs 8020 in differing arrangements may be provided. For example, two, three, four, five, six or more prongs 8020 may be provided. The implemented arrangement may correspond to an arrangement of a female engagement structure that defines the second engagement structure incorporated into the clip 3800-2.

[0363] In addition, similar to the exemplary headgear connectors 3600-1, the exemplary headgear connector 3600-2 may include a frame 7004. The frame may provide an interface engagement structure that may be used to secure the headgear connector 3600-2 to a point, such as connection point 3356, 3356-3, of a patient interface, such as patient interface 3000-1, 3000-3. In other respects, the headgear connector 3600-2 may function similarly and may have similar features as those described above in regards to headgear connector 3600-1.

5.3.3.4.3 Post and Stopper Slide Mechanism

[0364] Fig. 9A shows the patient interface 3000-3 including a headgear connector 3600-3 in accordance with one form of the present technology. Figs. 9B, 9C, and 9D respectively show overhead, bottom, and side perspective views of a retainer 3700-3 of the headgear connector 3600-3 in accordance with one form of the present technology. Figs. 9E, 9F, and 9G respectively show overhead, bottom, and side perspective views of a clip 3800-3 of the headgear connector 3600-3 in accordance with one form of the present technology. As described in more detail below, the clip 3800-3 may be configured to engage and be secured to the retainer 3700-3 according to a type of engagement that may be mechanical and in some aspects may be void of any magnetic components. Thus, the retainer 3700-3 may not include a magnet and may be configured to be releasably engaged by the clip 3800-3 of the headgear connector 3600-3. The clip 3800-3 may be configured to engage the retainer 3700-3 and thereby be secured to a patient interface, for example as shown in Fig. 9 A with the patient interface 3000-3. The retainer 3700-3 and the clip 3800-3 may also be configured to be engaged and disengaged by a user with, for example, one hand. As discussed above in regards to the headgear connector 3600-1, the headgear connector 3600-3 may be located at a connection point 3356-3 of patient interface 3000-3, for example, a flange 3550.

[0365] As shown in FIG. 9B, the retainer 3700-3 includes a tab surface 9002 extending distally from a first proximal end 9000A of the retainer 3700-3. A first engagement structure 9010 extends from a first base surface 9008A of a first base wall 9008 and is spaced apart from a distal region 9000B of the retainer 3700-3. The first engagement structure 9010 includes a post 9012 extending up from the first base surface 9008A and a stopper 9514 disposed at an end of the post 9012 opposite an end extending from the first base surface 9008A. The stopper 9514 may have a width that is greater than a width of the post 9012. The stopper 9514 may be, e.g., disk-shaped or bulbous and may have edges that are chamfered, bevelled, rounded, or formed at a right angles with an exposed surface 9016.

[0366] As shown in Figs. 9C and 9D, similar to the exemplary headgear connectors 3600-1, 3600-2, the exemplary retainer 3700-3 for the headgear connector 3600-3 includes a frame 7004. The frame 7004 may provide an interface engagement structure that may be used to secure the headgear connector 3600-3 to a connection point (as described in reference to headgear connector 3600-1), such as connection points 3356, 3356-3, of a patient interface, such as patient interfaces 3000-1, 3000-3. [0367] In addition to an outer surface of a body of the stopper 9014, an exposed surface 9016 of the stopper 9014 may be configured to engage a portion of the clip 3800. In some forms of the present technology, the outer surface of the stopper may be configured to engage surfaces of a second receiver 9550, discussed below with reference to Figs. 9H, 91, and 9K. Furthermore in some forms of the present technology, the exposed surface 9016 may be configured to contact, or rest adjacent to, a second base surface 9508A (see e.g., Figs. 9F and 91) during an engagement process. In forms of the present technology, the exposed surface 9016 may be configure to be in contact with or adjacent to the second base surface 9508A when the first engagement structure 9010 is engaged with a second engagement structure 9510 of the clip 3800-3, as will be explained below with reference to Figs. 9E-9K.

[0368] Figs. 9E, 9F, and 9G respectively show overhead, bottom, and side perspective views of the clip 3800-3 of the headgear connector 3600-3 in accordance with one form of the present technology. Fig. H provides a partial, perspective zoomed in view of a portion of the headgear connector of Fig. 9F. As shown in Fig. 9E, the clip 3800-3 may include a crossbar 9504, one or more slots, or another suitable mechanism around or through which a strap, such as the inferior straps 3304- 1, may be passed to secure the clip 3800-3 thereto. As shown in Fig. 9F, the clip 3800-3 further includes a second base wall that is defined, in part, by the second base surface 9508A and as second edge 9508B.

[0369] As shown in Figs. 9F and 9H, the second engagement structure 9510 may include: (1) a first receiver 9520 spaced apart from the second base surface 9508 A; and (2) a second receiver 9550 (see e.g., Figs. 9H, 91, and 9J) extending between the second base surface 9508A and the first receiver 9520. In one example, the combination of the second base surface 9508A and the first and second receivers 9520, 9550 define a slot 9560 (see e.g., Fig. 91) and thereby define a female engagement structure that may be configured to receive the stopper 9514 of the male engagement structure of the retainer 3700-3 between the first receiver 9520 and the second base surface 9508A, as explained in more detail below with reference to Figs. 9A-9C and 9L-9O.

[0370] Staying with Figs. 9F and 9H, the first receiver 9520 may extend from a proximal surface 9500A of a body 9500 of the clip 3800-3, to first end faces 9524 thereof. Further, the first receiver 9520 includes a first connecting wall 9522, a partition 9526, and a receiver transition 9528 incorporated into the partition 9526. The first connecting wall 9522 is formed between the proximal surface 9500A and the partition 9526, and includes: (1) a first rim 9523 that extends from the proximal surface 9500A; and (2) flanks 9525 that extend outward and distally from opposite sides of the first rim 9523.

[0371] As shown in Fig. 9H, each flank 9525 extends between a side surface 9500B of the clip 3800-3 and a first surface 9520A of the first receiver 9520, and is spaced apart from a respective leg 9529 of the partition 9526. Surfaces of the legs 9529 face one another and define first surfaces 9520A of the first receiver 9520. The legs 9529 extend from a head 9527 of the partition 9526 which may correspond to, and may be flanked by the first rim 9523 and a channel 9530 defined by the first surface 9520A. An inner surface of the head 9527 and legs 9529 respectively provide proximal and distal portions of a second surface 9520B of the first receiver 9520. [0372] The partition 9526 may be a continuous structure including a receiver transition 9528 between each leg 9529 (and respective distal portion of the second surface 9520B), and a corresponding end of the head 9527 from which the leg 9529 extends (and respective proximal portion of the second surface 9520B). Each receiver transition 9528, in some exemplary forms of the present technology, may be formed as a protruding edge extending into an area between a first receiving space defined by the legs 9529 and a second receiving space 9540 defined by the head 9527. Together, the receiver transitions 9528 are disposed on opposite sides of a neck area 9528A. In one example, a distance between the receiver transitions 9528 in a direction perpendicular to a longitudinal axis of the clip 3800-3 defines a width of the neck area 9528A that may be less than a diameter of the post 9012 of the first engagement structure 9010 of the retainer 3700-3. [0373] As will be described in more detail with reference to Figs. 9L-9O, engagement between the retainer 3700-3 and the clip 3800-3 may include: (1) the second engagement structure 9510 (female engagement structure) moving relative to the post 9012 of the first engagement structure 9010 (male engagement structure); (2) the relative movement causing the receiver transitions 9528 to engage the post 9012 of the first engagement structure 9010; (3) the post 9012 pushing or otherwise causing the receiver transitions 9528, and thus the legs 9529, to deflect away from each other (assuming a force causing the relative movement is adequate to overcome a material bias exhibited by the partition 9526 at the receiver transitions 9528); and (4) the head 9527 surrounding the post 9012 and thereby securing the clip 3800-3 to the retainer 3700-3 with the stopper 9514 of the male engagement structure of the retainer 3700-3 positioned between the first receiver 9520 and the second base surface 9508A in the slot 9560.

[0374] Fig. 91 shows a cross-sectional view of the clip 3800-3 from a plane corresponding to line 91-91 from Fig. 9E, looking in a direction I as indicated in Fig. 9E. As shown in Fig. 91, the slot 9560 includes a space defined between the first receiver 9520 and the second base wall 9508. Furthermore, as also shown in Fig. 91, the slot 9560 is defined by surfaces of the second receiver 9550 which may include a lead wall 9552 and sidewalls 9553 that extend from the lead wall 9552 and terminate at the second end faces 9554 (see e.g., Fig. 9J). In the illustrated example, the sidewalls 9553 may converge in a direction moving from the second end faces 9554 toward the lead wall 9552. In some forms, the sidewalls 9553 may function as a guide for the second engagement structure 9510 as the clip 3800-3 moves distally relative to the first engagement structure 9010. More specifically, a reactive force created by contact between the sidewalls 9553 and the stopper 9514 during this movement may cause the clip 3800-3 to move relatively such that the post 9012 may be substantially centered between the flanks 9525 and about the head 9527 of the partition 9526.

[0375] Figs. 9J shows a cross-sectional view of the clip from a plane corresponding to line 9J-9J from Fig. 9F, looking in a direction J as indicated in Fig. 9F. As shown in 9J, portions of a surface of the lead wall 9552 may include a stopper contact surface 9552A and a partition contact surface 9552B. The stopper contact surface 9552A may correspond to a portion of the lead wall 9552 that extends from the second base surface 9508 A to a point or level corresponding to a top edge 9521 of the head 9527 of the partition 9526. On the other hand, a partition contact surface 9552B may extend from this point or level to a second rim 9535. As shown, the second rim 9535 may define a transition (e.g., a step wall or surface) between the second receiver 9550 and a proximal portion of the first surface 9520A of the receiver 9520, at least in an area of the lead wall 9552.

[0376] In some forms of the present technology, the second rim 9535 may further define the channel 9530 that is generally defined between the partition 9526 and the first connecting wall 9522 by the first surface 9520A (Figs. 9F, 9H). A lead section 9531 of the channel 9530 may be defined as that section of the channel 9530 that is closed or otherwise bounded by the second rim 9535 as a result of the abutment between the partition 9526 and the second receiver 9550. More specifically, the lead section 9531 corresponds to an area of the head 9527 where the distal portion of the first surface 9520A is in contact with the partition contact surface 9552B. Thus, the lead section 9531 may be defined by the second rim 9535 and thereby provide a closed section of the channel 9530. The inclusion of the channel 9530 allows the partition 9526 to move and deflect somewhat relative to the first connecting wall 9522, which may alleviate an assembly and disassembly force.

[0377] As discussed above, the partition contact surface 9552B may face and be in abutment with the distal portion of the first surface 9520A - at least over an area of at least a portion of the head 9527. As explained in further detail with reference to Fig. 9K, the contact between the distal portion of the first surface 9520A and the partition contact surface 9552B may provide a backstop preventing linear movement of the partition 9526 when the post 9012 of the male engagement structure is engaged by the receiver transitions 9528 of the female engagement structure.

[0378] Fig. 9K shows a cross-sectional view of the clip 3800-3 from a plane corresponding to line 9K-9K from Fig. 9G, looking in a direction K as indicated in Fig. 9G. As shown in Fig. 9K, the top edge 9521 of the partition 9526 may be in abutment with the lead wall 9552, and thereby block a view of the channel 9530 of the area, or there may be a space between the top edge 9521 of the partition 9526 and the lead wall 9552. Side sections 9533 of the channel 9530 in the areas between the legs 9529 of the partition 9526 and the flanks 9525 of the first connecting wall 9522 may define an open channel 9530. Furthermore, the side sections 9533 of the channel 9530 define gaps in which the legs 9529 and receiver transitions 9528 may elastically deform (e.g., spread or separate) at least when the receiver transitions 9528 engage the post 9012 as the clip 3800-3 slides along the retainer 3700-3 in a direction from the first proximal end 9000A towards the first engagement structure 9010 and the distal region 9000B. As previously noted, movement of the partition 9526 towards the second receiver 9550 is inhibited by the contact there between over the area corresponding to the lead section 9531 of the channel 9530 described above and identified in Figs. 9F and 9J.

[0379] Figs. 9L-9O show the headgear connector 3600-3 in multiple states of engagement in accordance with one form of the present technology. More specifically, Fig. 9L illustrates a disengaged state of the headgear connector 3600-3, wherein the clip 3800-3 is positioned over the retainer 3700-3. In one example, Fig. 9L illustrates the clip 3800-3 in an exemplary position relative to the retainer 3700-3 such that the second engagement structure 9510 is ready for engagement with the first engagement structure 9010. In one example, this may include the stopper 9514 being generally in spatial alignment with an area of the clip 3800-3 between the crossbar 9504 and the first and second end faces 9524, 9554.

[0380] Fig. 9L illustrates one aspect of a level of usability provided by the exemplary headgear connector 3600-3. More specifically, in attempting to attach the clip 3800-3 to the retainer 3700-3, a patient may use the same hand to hold the clip 3800-3 and locate the retainer 3700-3. That is, a patient may use a finger that is not touching the clip 3800-3 to search for and locate the stopper 9514 of the retainer 3700-3 without significant effort. Furthermore, the patient may use the stopper 9514 to guide a movement of the clip 3800-3 toward the retainer 3700-3 generally, and engagement therewith specifically.

[0381] A capability of a patient to use one hand to perform the actions mentioned above may be attributed to the stopper 9514 having a readily recognizable shape and an elevated position relative to a remainder of the retainer 3700-3. In addition, the exposed surface 9016 of the stopper 9514 may be formed with one or more structural elements, such as dimples, bumps, grooves, recesses, serrations, ridges, knurling, texturing, and the like, to enhance a distinctiveness of a feeling of the stopper 9514. Such structural features may also be incorporated on the surface of the body of the stopper 9514 extending normal to the exposed surface 9016, or additionally or alternatively may be incorporated on other portions of retainer 3700-3, such as tab surface 9002 (shown with bumps in Fig. 9B). Accordingly, some patients who may have difficulty gripping objects because of dexterity issues, may be accommodated to the extent that they may be able to attach the clip 3800-3 to the retainer 3700-3 with one hand. As discussed above in regards to the headgear connector 3600-3, although one-handed use is described, two-handed use is also contemplated.

[0382] With this general alignment, the clip 3800-3 may be moved toward the retainer 3700-3 and into a position corresponding to the first partially engaged state shown in Fig. 9M. In one example, the exposed surface 9016 of the stopper 9514 may be in contact with a portion of the second base surface 9508A (see e.g., Fig. 9H). In use, the clip 3800-3 may be positioned such that a central region of an area surround by the head 9527 is substantially aligned with a central longitudinal axis of the post 9012. Such alignment may result in the receiver transitions 9528 (see e.g., Figs. 9F and 9H) engaging the post 9012 without preceding contact between the post 9012 and one of the legs 9529 of the partition 9526. However, as previously discussed, the converging configuration of the legs 9529 may ensure the receiver transitions 9528 are moved into an initial engagement with the post 9012, as shown in Fig. 9N, with movement of the clip 3800-3 in a direction away from the first proximal end 9000A of the retainer 3700-3.

[0383] Fig. 9N shows a second partially engaged state of the headgear connector 3600-3. As previously noted, in the position illustrated in Fig. 9N, the receiver transitions 9528 of the first receiver 9520 may be engaged with a surface of the post 9012. In one example, the second partially engaged state may correspond a point in an engagement process just before or as the receiver transitions 9528 start to deflect away from one another. As noted above with reference to Figs. 9J and 91, the side sections 9533 of the channel 9530 provide a clearance area that may accommodate this outward movement of the receiver transitions 9528 and legs 9529.

[0384] In some forms of the present technology, the retainer 3700-3 and the clip 3800-3 may be formed with different materials. In one example, the clip 3800-3 may be formed of a plastic, e.g., a thermoplastic polymer material, such as a polycarbonate material. The retainer 3700-3 may be formed from a plastic, e.g., a thermoplastic polyester elastomer material, which may have a stiffness less than that of the clip 3800-3. As described above in reference to the retainer 3700-1 and the clip 3800-1, the retainer 3700-3 and the clip 3800-3 may be formed of the same material or different materials, and/or parts of the retainer 3700-3 and the clip 3800-3 may be formed of the same or different materials.

[0385] As one of ordinary skill with recognize, at least until midpoints of the receiver transitions 9528 progress past a central longitudinal axis of the post 9012, the outward deflection of the receiver transitions 9528 and legs 9529 may continue with the movement of the clip 3800-3 away from the proximal end 9000A of the retainer 3700-3. However, after that axis is passed, a material bias of the partition 9526 may provide a spring-like effect causing the legs 9529 and receiver transitions 9528 to move (contract) or be biased to move towards one another back to their original position. Further, the head 9527 may engage a surface of the post 9012 with the proximal portion of the second surface 9520B of the first receiver 9520, as shown in 90.

[0386] Fig. 90 illustrates an engaged state for the headgear connector 3600-3. As shown, the stopper 9514 may be in contact with the second receiver 9550, and the post 9012 may be in contact with a second surface 9520B of the first receiver 9520. [0387] Figs. 9M-9O also demonstrate some additional exemplary aspects of usability that may be provided by the exemplary headgear connector 3600-3. In particular, engagement between the first and second engagement structures 9010, 9510 may be effected by movement of the clip 3800-3 away from the proximal end 9000A of the retainer 3700-3. Further, the respective exemplary circular and cylindrical configurations of head 9527 and post 9012, may allow for some deviation from longitudinal axes of the retainer 3700-3 and the clip 3800-3 being in complete alignment, without hindering a patient’s ability to progress from the first or second partially engaged state, ultimately to the engaged state shown in Fig. 90.

[0388] One of ordinary skill in the art will recognize that other shapes may be used as a basis for the designs of engaging components of the headgear connector 3600-3. Such flexibility may be enabled, in part, by the converging configuration of the legs 9529. The legs 9529 of the first receiver 9520 may guide a movement of the clip 3800-3 against and relative to the post 9012 and the stopper 9014. The legs 9529 may guide a movement of the clip 3800-3 by acting as a funnel and directing movement of the post 9012 and the stopper 9014 as they are received within the clip 3800-3 so as to move the post 9012 and the stopper 9014 toward the receiver transitions 9528 and the head 9527. [0389] Further with respect to usability, engagement of the clip 3800-3 to the retainer 3700-3 may be indicated by feedback that signals to a patient that the clip 3800-3 and the retainer 3700-3 are engaged, disengaged, or both. For example, in moving the clip 3800-3 from the second partially engaged state shown in Fig. 9N to the exemplary engaged state of Fig. 90, the post 9012 may be snapped into the head 9527. This may result in one or both of auditory and haptic feedback to the patient. On one hand, snapping the head 9527 into position around the post 9012 may create a snapping sound that can serve as notice that an engagement has been accomplished. As far as haptic feedback, the patient may feel the overcoming of a resistive force applied by the receiver transitions 9528 on the post 9012. Additionally, or alternatively, the patient may feel the impact of the post 9012 and/or the stopper 9014 respectively against the second surface 9520B of the first receiver 9520 and/or the stopper contact surface of the second receiver 9550, or a vibration caused by the same. Disengaging the clip 3800-3 from the retainer 3700-3 may similarly provide one or both of auditory and haptic feedback.

[0390] The exemplary configurations of the head 9527 and the post 9012 may help facilitate engagement in situations where there is less than perfect longitudinal alignment between the retainer 3700-3 and the clip 3800-3. This configuration may also allow for some rotation of the clip 3800-3 about post 9012 and relative to the retainer 3700-3 as a patient wears the patient interface 3000-3, for example, while moving when awake and/or sleeping. Some movements by the patient that may cause this rotation may, if not accommodated by the relative rotation of the headgear connector 3600-3, cause certain tensile or other forces to be applied to the patient by one or more components of the patient interface. In turn, the patient could experience varying degrees of discomfort if not for the limited rotation allowed for between the clip 3800-3 and the retainer 3700-3 in accordance with the present technology. In some aspects, if relative rotation of the clip 3800-3 and the retainer 3700-3 is not permitted, then the forces applied during movements may cause the clip 3800-3 and the retainer 3700-3 to disengage, resulting in unintended loosening or falling off of the patient interface, which may interrupt the intended treatment from being provided. Thus, such movements may go unnoticed or generally not be considered bothersome by the patient and/or may reduce the occurrence of unintentional loosening or removal of the patient interface. Further, the incorporation of the channel 9530 may allow the partition 9526 to move freely and deflect slightly, which may also allow the clip 3800-3 and the retainer 3700-3 to move relative to one another without disengaging.

5.3.3.4.4 Open Receiver Post Slide Mechanism

[0391] Fig. 10A shows a headgear connector 3600-4 attached to a patient interface 3000-4 in accordance with one form of the present technology. The headgear connector 3600-4 may include a retainer 3700-4 and a clip 3800-4. The clip 3800-4 may be detachably connected to a slide 10570 through which a headgear strap, such as inferior straps 3304-1, 3304-2, may be looped. Slide 10570 may alternatively be one or more of a crossbar, one or more slots, or other suitable mechanisms around or through which a strap may be passed and secured to the clip 3800-4. As described in more detail below, a female or male engagement structure of a second engagement structure 10510 of the clip 3800-4 may be positioned relative to a male or female engagement structure of a first engagement structure 10010 of the retainer 3700-4, and the clip 3800-4 may be moved in an engaging direction E (Fig. 10 E) until the headgear connector 3600-4 is in an engaged state, such as the exemplary engaged state depicted in Fig.lOA and 10G. As described in more detail below, the clip 3800-4 may be configured to engage and be secured to the retainer 3700-4 according to a type of engagement that may be mechanical and in some aspects may be void of any magnetic components.

[0392] Figs. 10A and 10B show a first engagement structure 10010 of the retainer 3700-4 in accordance with one form of the present technology. In one example, the first engagement structure 10010 may include the base surface 10008A and a male engagement structure 10020 extending from the base surface 10008A. Furthermore, the male engagement structure 10020 may include: a post 10022 extending from the base surface 10008A; an exposed surface 10026 disposed at an end of the male engagement structure 10020 opposite an end extending from the base surface 10008A; and a ridge 10024 protruding outward from a surface of the male engagement structure 10020 between the post 10022 and the exposed surface 10026. In the exemplary form illustrated in Figs. 10A and 10B, the exposed surface 10026 may have a curved, dome-like, profile, a flat surface, or a concave or convex surface. [0393] In some forms of the present technology, the base surface 10008A may be formed as part of or attached to a component, flange, or frame positioned on or secured to a plenum chamber of the patient interface 3000-4, as described above in reference to headgear connector 3600-1. In some aspects, the male engagement structure 10020 may be formed as one monolithic component with the base surface 10008A and thereby define a connection point 3356-4 for the exemplary headgear connector 3600-4 illustrated in Figs. 10A-10C. In other forms, the male engagement structure 10020 may be a separate component affixed to the base surface 10008A. [0394] Fig. 10C shows the clip 3800-4 in accordance with one form of the present technology. The clip 3800-4 includes a second body 10500 that has side surfaces 10500B and a proximal surface 10500A. In one form, the proximal surface 10500A extends from a second proximal end of the clip 3800-4 and transitions into the side surfaces 10500B as shown in Fig. 10C. The second engagement structure 10510 may include a base 10512 and a receiver 10520 which includes a first connecting wall 10522 and a partition 10526.

[0395] As shown in Fig. 10C, the first connecting wall 10522 may include a rim 10523 and flanks 10525. In some forms, the rim 10523 extends from the proximal surface 10500A of the clip 3800-4 to a first surface 10520A of the receiver 10520. The first surface 10520A defines a channel 10530 disposed between the first connecting wall 10522 and the partition 10526. The inclusion of the channel 10530 allows the partition 10526 to move and deflect somewhat relative to the first connecting wall 10522, which may alleviate an assembly and disassembly force. The flanks 10525 may extend from opposite sides of the rim 10523 and side surfaces 10500B of the clip 3800-4, to a second connecting wall 10550 of the receiver 10520. As shown in Fig. 10C, a proximal portion of each flank 10525 extends between a respective side surface 10500B of the clip 3800-4 and the first surface 10520A and is disposed outside of a respective leg 10529 of the partition 10526.

[0396] The partition 10526, as shown in Fig. 10C, includes a head 10527 and the previously mentioned legs 10529, which may extend from the head 10527. The head 10527 may correspond to, and be surrounded by, the rim 10523 and the channel 10530 defined by the first surface 10520A. The partition 10526 may be a continuous structure including a receiver transition 10528 formed between each leg 10529 and a corresponding end of the head 10527. Together, the receiver transitions 10528 define a neck area 10528A and may correspond to a boundary between first and second receiving spaces 10540, 10542 of the receiver 10520. In one form, the first receiving space 10540 may be defined by that area within the clip that is bounded by a distal portion of a second surface 10520B of the receiver 10520 as defined by the legs 10529 and the second connecting wall 10550. The second receiving space 10542 may be defined by that area surrounded by a proximal portion of the second surface 10520B of the receiver 10520 as defined by the head 10527.

[0397] In one example, a distance between the receiver transitions 10528 in a direction perpendicular to a longitudinal axis of the clip 3800-4 defines a width of the neck area 10528A that is less than a diameter of the post 10022 of the first engagement structure 10010 on the retainer 3700-4. As will be described in more detail with reference to Figs. 10D-10G, engagement between the retainer 3700-4 and the clip 3800-4 may include: (1) aligning the first receiving space 10540 with the exposed surface 10026 of the first engagement structure 10010 and moving the clip 3800-4 toward the retainer 3700-4 such that the legs 10529 and second connecting wall receive the post 10022; (2) moving the clip (distally) to cause the receiver transitions 10528 to engage the post 10022 of the first engagement structure 10010; (3) the post 10022 pushing or otherwise causing the receiver transitions 10528 to deflect outward away from one another (assuming a force causing the movement is adequate to overcome a material bias exhibited by the partition 10526 at the receiver transitions 10528); and (4) the head 10527 receiving the post 10022 and thereby securing the clip 3800-4 to the retainer 3700-4.

[0398] Figs. 10D-10G show the headgear connector 3600-4 in multiple states of engagement in accordance with one form of the present technology. More specifically, Fig. 10D illustrates a disengaged state of the headgear connector 3600-4 wherein the clip 3800-4 is positioned over the retainer 3700-4. In one example, Fig. 10D illustrates the clip 3800-4 in an exemplary position relative to the retainer 3700-4 such that the second engagement structure 10510 is ready for engagement with the first engagement structure 10010. In one example, this may include the first receiving space 10540 being generally aligned with the exposed surface 10026 of the male engagement structure. With this alignment, the clip 3800-4 may be moved toward the retainer 3700-4 and into a position corresponding to the first partially engaged state shown in Fig. 10E.

[0399] As noted above, Fig. 10E shows the headgear connector 3600-4 in a first partially engaged state. The exposed surface 10026 of the male engagement structure may extend above, lay flush with, or may be slightly recessed relative to a surface of the clip 3800-4, and the legs 10529 may be in contact with the post 10022 (see Fig.

10D). In one example, the post 10022 may also be in contact with leading edges of the legs 10529/trailing edges of the receiver transitions 10528. Movement of the clip 3800-4 in the engaging direction E from the position depicted in Fig. 10E, may move the post 10022 into substantial engagement with the receiver transitions 10528 as shown in Fig. 10F.

[0400] Fig. 10F shows a second partially engaged state of the headgear connectors 3600-4. In one example, the second partially engaged state may correspond with a point in an engagement process at which the receiver transitions 10528 are deflected away from one another to allow the post 10022 to move past the receiver transitions 10528. As shown, the channel 10530 includes a lead section 10531 extending around the head 10527 of the partition 10526, and side section 10533 extends along the periphery of the legs 10529. The side sections 10533 of the channel 10530 provide a clearance area that accommodates the outward movement of the receiver transitions 10528.

[0401] Fig. 10G illustrates an engaged state for the headgear connector 3600-4. As shown, the post 10022 may be received by the partition 10526 with the ridge 10024 overlapping with a portion of a partition surface 10526A. In one form of the present technology, the steps illustrated in Figs. 10D to 10G may be performed in reverse to disengage the clip 3800-4 from the retainer 3700-4.

[0402] Fig. 10H shows a front view of the headgear connector 3600-4 in a partially disengaged state, in accordance with one form of the present technology. The ridge 10024 of the first engagement structure 10010 may be sized such that when a force away from a patient interface is applied to, for example, one of the side surfaces of the clip 3800-4, a patient may disengage the headgear connector 3600-4. According to an aspect of the present technology, both methods of disengaging the headgear connector 3600-4 described above may be performed with one hand by a patient. However, one of ordinary skill in the art will appreciate that some patients may have a concern that the process represented in Fig. 10H may occur without the patient initiating the process. Accordingly, some forms of the present technology may include a ridge 10024 configured to overlap a substantial portion of the partition surface 10526A and thereby remove the option for disengagement represented in Fig. 10H. In such a form of the present technology, disengaging the clip 3800-4 from the retainer 3700-4 may involve sliding the post 10022 back past the receiver transitions 10528 and back into the first receiving space 10540, then lifting the clip 3800-4 away from the retainer 3700-4.

[0403] Further with respect to usability, engagement of the clip 3800-4 to the retainer 3700-4 may be indicated by feedback that signals to a patient that the clip 3800-4 and the retainer 3700-4 are engaged, disengaged, or both. For example, in moving the clip 3800-4 from the second partially engaged state shown in Fig. 10F to the exemplary engaged state of Fig. 10G, the post 10022 may be snapped into the second receiving space 10542. This may result in one or both of auditory and haptic feedback to the patient. On one hand, snapping the second receiving space 10542 into position around the post 10022 may create a snapping sound that can serve as notice that an engagement has been accomplished. As far as haptic feedback, the patient may feel the overcoming of a resistive force applied by the receiver transitions 10528 on the post 10022. Additionally, or alternatively, the patient may feel the impact of the post 10022 against the head 10527 of the partition 10526, or a vibration caused by the same. Disengaging the clip 3800-4 from the retainer 3700-4 may similarly provide one or both of auditory and haptic feedback.

[0404] The exemplary configurations of the head 10527 and the post 10022 may help facilitate engagement in situations where there is less than perfect longitudinal alignment between the retainer 3700-4 and the clip 3800-4. This configuration may also allow for some rotation of the clip 3800-4 about post 10022 and relative to the retainer 3700-4 as a patient wears the patient interface 3000-4, for example, while moving when awake and/or sleeping. Some movements by the patient that may cause this rotation may, if not accommodated by the relative rotation of the headgear connector 3600-4, cause certain tensile or other forces to be applied to the patient by one or more components of the patient interface. In turn, the patient could experience varying degrees of discomfort if not for the limited rotation allowed for between the clip 3800-4 and the retainer 3700-4 in accordance with the present technology. In some aspects, if relative rotation of the clip 3800-4 and the retainer 3700-4 is not permitted, then the forces applied during movements may cause the clip 3800-4 and the retainer 3700-4 to disengage, resulting in unintended loosening or falling off of the patient interface, which may interrupt the intended treatment from being provided. Thus, such movements may go unnoticed or generally not be considered bothersome by the patient and/or may reduce the occurrence of unintentional loosening or removal of the patient interface. Further, the incorporation of the channel 10530 may allow the head 10527 to move freely and deflect slightly, which may also allow the clip 3800-4 and the retainer 3700-4 to move relative to one another without disengaging.

[0405]

5.3.3.4.5 Tab Slide Mechanism

[0406] Fig. 11 A shows a patient interface 3000-4 including a headgear connector 3600-5 in accordance with one form of the present technology. As described in more detail below, the clip 3800-5 may be configured to engage and be secured to the retainer 3700-5 according to a type of engagement that may be mechanical and in some aspects may be void of any magnetic components. As shown in Fig. 11A, the patient interface 3000-5 may include: a plenum chamber 3200-5; a positioning and stabilising frame 3370-5 (e.g., detachably connected to the plenum chamber); a vent 3400-5 connected to the plenum chamber 3200-5; superior straps 3305-5 attached to the positioning and stabilising frame 3370-5; the headgear connectors 3600-5; and inferior straps 3304-5 attached to the headgear connectors 3600-5. In one form of the present technology the positioning and stabilising frame 3370-5 is comprised of a frame body 3372-5 and first and second arms 3374-5 (e.g., lower), 3376-5 (e.g., upper) extending from each lateral side of the frame body 3372-5. In the exemplary assembled state illustrated in Fig. 11 A, the frame body 3372-5 surrounds the vent 3400-5, and retainers 3700-5 for the headgear connectors 3600-5 extend from the first arms 3374-5, which extend from the frame body 3372-5. The arms 3374-4 and retainer 3700-5 may be integrally formed in one piece, from the same material, with the frame body 3372-5. The headgear connectors 3600-5 may take the form as shown in Figures 7A to 7Z, e.g., a non-magnetic connection with a first engagement structure 7010 and clip 3800-1 with a through-opening to receive a post (e.g., see Fig. 11D). Each inferior strap 3304-5 may be looped around a crossbar 11504 (see e.g., Fig.

1 IB), one or more slots, or another suitable mechanism around or through which a strap, such as the inferior straps 3304-5, may be attached, of a respective clip 3800-5. Each superior strap 3305-5 may be looped around an end of a respective second arm 3376-5. A rear surface 3376-5S of arms 3376-5 may include a concave portion to help strengthen a portion of the arms 3376-5 close to the frame body 3372-5, e.g., as shown in Fig. 11D. [0407] Turning to Fig. 1 IB, the retainer 3700-5 includes a deflectable tab 11024 and a first base wall 11008 that extends from the first arm 3374-5 and surrounds a perimeter of the tab 11024. A bias wall 11022 may extend between the first base wall 11008 and the tab 11024. The first base wall 11008 includes a first base surface 11008A and a first edge 11008B that in some forms of the present technology, may contact or otherwise engage corresponding surfaces of the clip 3800-5 as discussed in more detail hereafter.

[0408] In one form, the bias wall 11022 may extend from the first base wall 11008 at an incline so that in an unengaged state, the tab 11024 is biased upward and sits at an angle relative to a plane of the first base surface 11008A. This may position the tab 11024 so that an end of the tab 11024 adjacent the first edge 11008B is positioned lower than an opposite end of the tab 11024, which may facilitate engagement. In other examples, the bias wall 11022 extends without an incline, and the tab 11024 may lie in a plane that is parallel to the first base surface 11008 A. The tab 11024 may be configured to have a height that is greater than a height of the first base surface 11008A so that the tab 11024 is configured to extend through and interlock with a portion of a receiver 11520 of the clip 3800-5 to prevent the clip 3800-5 from detaching from the retainer 3700-5 once engaged. Thus, the tab 11024 and the bias wall 11022 define a male engagement structure which, along with the first base wall 11008, define a first engagement structure 11010 of the retainer 3700- 5.

[0409] The retainer 3700-5 may additionally include a first backstop 11014 position above or below and adjacent to the first base wall 11008, e.g., as shown in Fig. 1 IB. The first backstop 11014 may include a curved profile corresponding to a curvature of a second edge 11508B defined by a proximal end of a second base wall 11508 of the clip 3800-5 or may have a shape that does not correspond to the curvature of the second edge 11508B. In some forms, the first backstop 11014 may limit the clip 3800-5 movement in an engaging direction E. In other forms, the backstop may serve to facilitate or guide a controlled and limited rotational movement of the clip 3800-5 relative to the retainer 3700-5.

[0410] As shown in Fig. 1 IB, the clip 3800-5 includes the second base wall 11508, side walls 11502 extending from, e.g., the crossbar 11504 or other connecting component as described above, to overlap a portion of the second base wall 11508, and a receiver 11520 extending from a connecting wall 11512. The receiver 11520 defines a female engagement structure of the clip 3800-5. In some forms, a second backstop 11514 is provided as a vertical wall extending from the second base wall 11508 to the connecting wall 11512 of the exemplary clip 3800-5. Together with the connecting wall 11512 and the second backstop 11514, the receiver 11520 provides a second engagement structure 11510 of the clip 3800-5.

[0411] In use, and starting from the disengaged state illustrated in Fig. 1 IB, the clip 3800-5 may be moved towards the retainer 3700-5. Once the portion of the connecting wall defining a front edge of the receiver 11520 engages the tab 11024, the tab 11024 may be depressed or otherwise deflected downward until it is generally flush with the first base surface 11008A. As movement of the clip 3800-5 in the engaging direction E continues, a surface of the second base wall 11508and a surface of the receiver 11520 of the clip 3800-5 may be in contact with, and slide relative to, the tab 11024 and the first base wall 11008. In particular, a second base surface 11508 A of a second base wall 11508 may contact and slide relative to a bottom surface 11008C of the first base wall 11008. Continued movement may bring a center of a receiving space 11540 defined by the receiver 11520 and the second base wall 11508 into substantial alignment with a center of the tab 11024, and the tab 11024 may be biased upward into the receiving space 11540. In one form of the present technology, a tab surface may slide along an inner surface of the receiver 11520 as the tab 11024 progresses into the receiving space 11540. One of ordinary skill in the art may recognize this process as the tab 11024 being snapped into the engaged state with the clip 3800-5.

[0412] Fig. 11C illustrates an exemplary engaged state for the headgear connector 3600-5. In one example, engagement of the tab 11024 may be accompanied by audible and/or haptic feedback that may be sensed by the patient so that the patient knows that the headgear connector 3600-5, and a strap, are securely engaged to the remainder of a patient interface. Similar haptic and/or auditory feedback may be generated upon disengaging the clip 3800-5 and the retainer 3700-5.

[0413] As shown in Fig. 11C with the headgear connector 3600-5 in the engaged state, the tab 11024 may be fit into the receiving space 11540 such that a substantial portion of the tab surface faces a surface of the receiver 11520. In one form of the present technology, the first edge 11008B of the first base wall 11008 may be in abutment, or close to being in abutment, with the second backstop 11514. Likewise, the second edge 11508B of the second base wall 11508 may be in abutment, or close to being in abutment, with the first backstop 11014.

[0414] The exemplary configurations of the receiver 11520 and the tab 11024 may allow for some rotation of the clip 3800-5 about the tab 11024 and relative to the retainer 3700-5 as a patient wears the patient interface 3000-5, for example, while moving when awake and/or sleeping. Some movements by the patient that may cause this rotation may, if not accommodated by the relative rotation of the headgear connector 3600-5, cause certain tensile or other forces to be applied to the patient by one or more components of the patient interface. In turn, the patient could experience varying degrees of discomfort if not for the limited rotation allowed for between the clip 3800-5 and the retainer 3700-5 in accordance with the present technology. In some aspects, if relative rotation of the clip 3800-5 and the retainer 3700-5 is not permitted, then the forces applied during movements may cause the clip 3800-5 and the retainer 3700-5 to disengage, resulting in unintended loosening or falling off of the patient interface, which may interrupt the intended treatment from being provided. Thus, such movements may go unnoticed or generally not be considered bothersome by the patient and/or may reduce the occurrence of unintentional loosening or removal of the patient interface.

5.3.3.4.6 Vertical Slide Mechanism

[0415] Fig. 12A shows a headgear connector 3600-6 in a disengaged state in accordance with one form of the present technology. As shown in Fig. 12A, the headgear connector 3600-6 includes a retainer 3700-6 and a clip 3800-5. As described in more detail below, the clip 3800-6 may be configured to engage and be secured to the retainer 3700-6 according to a type of engagement that may be mechanical and in some aspects may be void of any magnetic components. The retainer 3700-6 includes a first body 12000 that defines a slot 12010A, which forms a female engagement structure as a first engagement structure 12010. The first engagement structure 12010 includes at least one recess 12020 defined in a first surface 12012. In the illustrated example of Fig. 12A, the first engagement structure 12010 may include two recesses, one visible and one not visible as presented in Fig. 12 A, located in corresponding locations of respective opposing sides of the slot 12010A defined by the first surface 12012. In one form, the first surface 12012 defines the slot 12010A that may be configured to receive a post 12512 of the clip 3800-6.

[0416] The clip 3800-6 may include a crossbar 12504 and a second body 12500 that defines a male engagement structure as a second engagement structure 12510. As defined by the second body 12500, the second engagement structure 12510 may include a post 12512 and at least one protrusion 12520 (e.g., a bump) extending from a surface of the post 12512. In the illustrated example of Fig. 12A, two protrusions 12520, one visible and one not visible in Fig. 12A, may be provided in corresponding locations on opposite sides of the post 12512. The protrusions may be located so as to match up with the recesses 12020 of the retainer 3700-6 when: (1) the post 12512 is aligned with the slot 12010A; (2) the clip 3800-6 is moved in an engaging direction E toward the retainer 3700-6; (3) the post 12512 slides along the first surface 12012 of the first engagement structure 12010 until the protrusions 12520 engage the recesses 12020. Thus, in one form, the second engagement structure 12510 may include the post 12512 that is configured to move into, and securely engage, a structure defined on or in a surface (first surface 12012) of the first body 12000 that defines the slot 12010A, such that the first engagement structure 12010 may define a female engagement structure.

[0417] Although two protrusions 12520 and two recesses 12020 are described in relation to Figs. 12A and 12B, it is contemplated that one, three, four, or more protrusions 12520 and recesses 12020 may be included on the clip 3800-6 and the retainer 3700-6. Further, although a crossbar 12504 is described as being part of the clip 3800-6, one or more slots, slides, or other suitable mechanisms around or through which a strap may be passed and secured to the clip 3800-6 may be used.

[0418] In the illustrated example, a second surface 12014 of the first engagement structure 12010 may be defined by the first body 12000 and thereby define a closed end of the slot 12010A. In one form of the present technology, engagement between the first and second engagement structures 12010, 12510 may include a stopper 12514, having an end face of the post 12512, engaging the second surface 12014. As a result of this engagement, continued movement of the post 12512 in the engaging direction E is limited, and the headgear connector 3600-6 is moved into and remains in an exemplary engaged state illustrated in Fig. 12B. [0419] Engagement or disengagement of the clip 3800-6 and the retainer 3700-6 may be indicated by feedback that signals to a patient that the clip 3800-6 and the retainer 3700-6 are engaged, disengaged, or both. For example, in moving the clip 3800-6 from the disengaged state shown in Fig. 12A to the exemplary engaged state of Fig. 12B, the protrusions 12520 may be snapped into place within respective recesses 12020 (and thus the post 12512 snapped into the slot 12010A). This may result in one or both of auditory and haptic feedback to the patient. Snapping the protrusions 12520/post 12512 into position within the recesses 12020/slot 12010A may create a snapping sound that can serve as notice that an engagement has been accomplished. As far as haptic feedback, the patient may feel the overcoming of a resistive frictional force applied by the first surface 12012 on the protrusions 12520 as a result, or subsiding of a vibration caused by the same. Additionally, or alternatively, the patient may feel the impact of the stopper 12514 contacting the second surface 12014. The reverse interactions may similarly provide one or both of auditory and haptic feedback when disengaging clip 3800-6 and the retainer 3700-6.

5.3.4 Modularity

[0420] As described above, the cushion, headgear, and sleeves may come in different styles, which may correspond to different uses (e.g., mouth breathing, nasal breathing, etc.). A patient or clinician may select certain combinations of cushions, headgear, sleeves, and headgear connectors in order to optimize the effectiveness of the therapy and/or the individual patient’s comfort. An example of this sort of modular design is described in PCT/SG2022/050777 filed 28 October 2022, incorporated herein by reference in its entirety.

[0421] In some forms, the different styles of cushions, headgear, sleeves, and headgear connectors may be used interchangeably with one another in order to form different combinations of patient interfaces. This may be beneficial from a manufacturing prospective because wider variety of patient interfaces may be created using fewer parts. Additionally or alternatively, the various combinations may allow a patient to change styles of patient interface without changing the every component. [0422] Air may be delivered to the patient in one of two main ways. In one example, the patient may receive the flow of pressurized air through headgear tubes 3350 (see e.g., Figs. 3Y, 6C, 6H, and 7). This may be referred to as a “tube up” configuration and may position a connection port at the top of the patient’s head. In other examples, the patient may receive the flow of pressurized air through a conduit connected to the plenum chamber 3200, 3200-5 for example through the connection port 3470 in fluid communication with the vent 3400, 3400-5 (see e.g., Figs. 3A and 22). This may be referred to a “tube down” configuration where the airflow conduit is positioned in front of the patient’s face. Different patients may be more comfortable with one style of air delivery over the other (e.g., because of the patient’s sleep style). Therefore, it may be beneficial to allow a single style of patient interface to be used in either the “tube up” or “tube down” configuration.

[0423] The patient interface may be part of a modular assembly with a variety of interchangeable components that may be swapped out by a patient and/or clinician for one or more components for a different style. The following description describes the various combinations that may be created by assembling the different components together.

5.3.4.1 Sleeve

[0424] In some forms, to allow for modularity, a sleeve, such as the conduit sleeve 3351 discussed above, may be used with the tubes 3350 and/or the rigidiser arms 3340. As noted above, sleeves may at least partially surround tubes 3350 and/or rigidiser arms 3340; and different shapes of sleeves may be used (see, e.g., exemplary conduit sleeves 3351 depicted in Figs. 6G and 6H). In some forms, the different shapes may correspond to different types of positioning and stabilising structures 3300. In addition, in some forms, the configuration of the sleeve may be customized to fit a particular user’s face. For instance, the sleeves may be configured in a relatively more posterior region of the patient’s head.

[0425] In some forms, the sleeve may be constructed from a comfortable material. For example, the sleeve may be constructed from a textile material, a foam material, or a combination of the two. The comfortable material may contact the patient in use, and may feel soft against the patient’s skin in order to improve patient compliance.

[0426] The material may also be flexible in order to assist in donning or doffing the sleeve from the tube 3350 or the rigidiser arms 3340. For example, the material may allow the sleeve to bend in order to conform to the shape of the tubes 3350, other conduit headgear components, or the rigidiser arms 3340, which may change depending on the shape of an individual patient’s head. [0427] In some forms, the sleeve may also be at least partially elastic (e.g., the material may allow the sleeve to stretch). The elastic material may help the sleeve stretch in order to fit around the tubes 3350 or the rigidiser arms 3340. The elastic material may then return to an initial position that is snug against the tubes 3350 or the rigidiser arms 3340 in order to limit the sleeve from sliding while in use.

[0428] Some forms of the sleeves may be specific to a rigidising element (e.g., tubes 3350 and/or rigidiser arms 3340). However, the sleeves may assist the rigidising elements in connecting interchangeably with the version or styles of cushions (e.g., the mouth and nose cushion 3050-1, the nose-only cushion 3050-2, etc.).

5.3.4.2 Assembled Patient Interfaces

[0429] Various elements described above may be combined into different patient interfaces. The different patient interfaces may allow patients to use different styles based on their individual comfort. The modularity of the different elements (e.g., the ability to be used in multiple styles of patient interfaces) may simplify manufacturing and/or may allow a patient to more easily switch between styles of patient interfaces.

5.4 RPT DEVICE

[0430] An RPT device 4000 in accordance with one aspect of the present technology comprises mechanical, pneumatic, and/or electrical components and is configured to execute one or more algorithms, such as any of the methods, in whole or in part, described herein. The RPT device 4000 may be configured to generate a flow of air for delivery to a patient’s airways, such as to treat one or more of the respiratory conditions described elsewhere in the present document.

[0431] In one form, the RPT device 4000 is constructed and arranged to be capable of delivering a flow of air in a range of -20 L/min to +150 L/min while maintaining a positive pressure of at least 4 cmH20, or at least 10 cmH20, or at least 20 cmH20.

[0432] The RPT device may have an external housing 4010, formed in two parts, an upper portion 4012 and a lower portion 4014. Furthermore, the external housing 4010 may include one or more panel(s) 4015. The RPT device 4000 comprises a chassis 4016 that supports one or more internal components of the RPT device 4000. The RPT device 4000 may include a handle 4018.

[0433] The pneumatic path of the RPT device 4000 may comprise one or more air path items, e.g., an inlet air filter 4112, an inlet muffler 4122, a pressure generator 4140 capable of supplying air at positive pressure (e.g., a blower 4142), an outlet muffler 4124 and one or more transducers 4270, such as pressure sensors and flow rate sensors.

[0434] One or more of the air path items may be located within a removable unitary structure which will be referred to as a pneumatic block 4020. The pneumatic block 4020 may be located within the external housing 4010. In one form a pneumatic block 4020 is supported by, or formed as part of the chassis 4016.

[0435] As shown in Fig. 4A, the RPT device 4000 may have an electrical power supply 4210, one or more input devices 4220, a pressure generator 4140, and electrical components. The electrical components 4200 may be mounted on a single Printed Circuit Board Assembly (PCBA) 4202. In one example, the electrical components 4200 may include transducers 4270 shown in Fig. 4B, as well as several components that are not shown, which may include a central controller, a therapy device controller, one or more protection circuits, a memory, a data communication interface, and one or more output devices. In an alternative form, the RPT device 4000 may include more than one PCBA 4202.

5.4.1 RPT device mechanical & pneumatic components

[0436] An RPT device may comprise one or more of the following components in an integral unit. In an alternative form, one or more of the following components may be located as respective separate units.

5.4.1.1 Air filter(s)

[0437] An RPT device in accordance with one form of the present technology may include an air filter 4110, or a plurality of air filters 4110.

[0438] In one form illustrated in Fig. 4B, an inlet air filter 4112 is located at the beginning of the pneumatic path upstream of a pressure generator 4140.

[0439] In one form illustrated in Fig. 4B, an outlet air filter 4114, for example an antibacterial filter, is located between an outlet of the pneumatic block 4020 and a patient interface 3000.

5.4.1.2 Muffler(s)

[0440] An RPT device in accordance with one form of the present technology may include a muffler 4120, or a plurality of mufflers 4120.

[0441] In one form of the present technology (see e.g., Fig. 4B), an inlet muffler 4122 is located in the pneumatic path upstream of a pressure generator 4140. [0442] In one form of the present technology, an outlet muffler 4124 is located in the pneumatic path between the pressure generator 4140 and a patient interface 3000.

5.4.1.3 Pressure generator

[0443] In one form of the present technology, a pressure generator 4140 for producing a flow, or a supply, of air at positive pressure is a controllable blower 4142. For example, the blower 4142 may include a brushless DC motor 4144 with one or more impellers. The impellers may be located in a volute. The blower may be capable of delivering a supply of air, for example at a rate of up to about 120 litres/minute, at a positive pressure in a range from about 4 cmFEO to about 20 cmFhO, or in other forms up to about 30 cmFhO when delivering respiratory pressure therapy. The blower may be as described in any one of the following patents or patent applications the contents of which are incorporated herein by reference in their entirety: U.S.

Patent No. 7,866,944; U.S. Patent No. 8,638,014; U.S. Patent No. 8,636,479; and PCT Patent Application Publication No. WO 2013/020167.

[0444] The pressure generator 4140 may be under the control of the therapy device controller (not shown).

[0445] In other forms, a pressure generator 4140 may be a piston-driven pump, a pressure regulator connected to a high pressure source (e.g. compressed air reservoir), or a bellows.

5.4.1.4 Transducer(s)

[0446] Transducers may be internal of the RPT device, or external of the RPT device. External transducers may be located for example on or form part of the air circuit, e.g., the patient interface. External transducers may be in the form of noncontact sensors such as a Doppler radar movement sensor that transmit or transfer data to the RPT device.

[0447] In one form of the present technology (see e.g., Fig. 4B), one or more transducers 4270 are located upstream and/or downstream of the pressure generator 4140. The one or more transducers 4270 may be constructed and arranged to generate signals representing properties of the flow of air such as a flow rate, a pressure or a temperature at that point in the pneumatic path.

[0448] In one form of the present technology, one or more transducers 4270 may be located proximate to the patient interface 3000. [0449] In one form, a signal from a transducer 4270 may be filtered, such as by low-pass, high-pass or band-pass filtering.

5.4.1.5 Anti-spill back valve

[0450] As shown in Fig. 4B, one form of the present technology, an anti-spill back valve 4160 is located between the humidifier 5000 and the pneumatic block 4020. The anti-spill back valve is constructed and arranged to reduce the risk that water will flow upstream from the humidifier 5000, for example to the motor 4144.

5.4.2 RPT device electrical components

5.4.2.1 Power supply

[0451] A power supply 4210 may be located internal or external of the external housing 4010 of the RPT device 4000.

[0452] In one form of the present technology, power supply 4210 provides electrical power to the RPT device 4000 only. In another form of the present technology, power supply 4210 provides electrical power to both RPT device 4000 and humidifier 5000.

5.4.2.2 Input devices

[0453] In one form of the present technology, an RPT device 4000 includes one or more input devices 4220 in the form of buttons, switches or dials to allow a person to interact with the device. The buttons, switches or dials may be physical devices, or software devices accessible via a touch screen. The buttons, switches or dials may, in one form, be physically connected to the external housing 4010, or may, in another form, be in wireless communication with a receiver that is in electrical connection to a central controller that may be included with the electrical components 4200.

[0454] In one form, the input device 4220 may be constructed and arranged to allow a person to select a value and/or a menu option.

5.5 HUMIDIFIER

5.5.1 Humidifier overview

[0455] In one form of the present technology there is provided a humidifier 5000 (e.g. as shown in Fig. 5A) to change the absolute humidity of air or gas for delivery to a patient relative to ambient air. Typically, the humidifier 5000 is used to increase the absolute humidity and increase the temperature of the flow of air (relative to ambient air) before delivery to the patient’s airways. [0456] The humidifier 5000 may comprise a humidifier reservoir 5110, a humidifier inlet 5002 to receive a flow of air, and a humidifier outlet 5004 to deliver a humidified flow of air. In some forms, as shown in Fig. 5A and Fig. 5B, an inlet and an outlet of the humidifier reservoir 5110 may be the humidifier inlet 5002 and the humidifier outlet 5004 respectively. The humidifier 5000 may further comprise a humidifier base 5006, which may be adapted to receive the humidifier reservoir 5110 and comprise a heating element 5240.

5.6 GLOSSARY

[0457] 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

[0458] 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.

[0459] 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.

[0460] For example, ambient humidity with respect to a humidifier may be the humidity of air immediately surrounding the humidifier, e.g. the humidity in the room where a patient is sleeping. Such ambient humidity may be different to the humidity outside the room where a patient is sleeping.

[0461] In another example, ambient pressure may be the pressure immediately surrounding or external to the body.

[0462] In certain forms, ambient (e.g., acoustic) noise may be considered to be the background noise level in the room where a patient is located, other than for example, noise generated by an RPT device or emanating from a mask or patient interface. Ambient noise may be generated by sources outside the room.

[0463] Automatic Positive Airway Pressure (APAP) therapy. CPAP therapy in which the treatment pressure is automatically adjustable, e.g. from breath to breath, between minimum and maximum limits, depending on the presence or absence of indications of SDB events. [0464] 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.

[0465] Flow rate-. The volume (or mass) of air delivered per unit time. Flow rate may refer to an instantaneous quantity. In some cases, a reference to flow rate will be a reference to a scalar quantity, namely a quantity having magnitude only. In other cases, a reference to flow rate will be a reference to a vector quantity, namely a quantity having both magnitude and direction. Flow rate may be given the symbol Q. ‘Flow rate’ is sometimes shortened to simply ‘flow’ or ‘airflow’.

[0466] In the example of patient respiration, a flow rate may be nominally positive for the inspiratory portion of a breathing cycle of a patient, and hence negative for the expiratory portion of the breathing cycle of a patient. Device flow rate, Qd, is the flow rate of air leaving the RPT device. Total flow rate, Qt, is the flow rate of air and any supplementary gas reaching the patient interface via the air circuit. Vent flow rate, Qv, is the flow rate of air leaving a vent to allow washout of exhaled gases. Leak flow rate, QI, is the flow rate of leak from a patient interface system or elsewhere. Respiratory flow rate, Qr, is the flow rate of air that is received into the patient's respiratory system.

[0467] Flow therapy. Respiratory therapy comprising the delivery of a flow of air to an entrance to the airways at a controlled flow rate referred to as the treatment flow rate that is typically positive throughout the patient’s breathing cycle.

[0468] Humidifier. The word humidifier will be taken to mean a humidifying apparatus constructed and arranged, or configured with a physical structure to be capable of providing a therapeutically beneficial amount of water (H2O) vapour to a flow of air to ameliorate a medical respiratory condition of a patient.

[0469] Leak. The word leak will be taken to be an unintended flow of air. In one example, leak may occur as the result of an incomplete seal between a mask and a patient's face. In another example leak may occur in a swivel elbow to the ambient. [0470] Noise, conducted (acoustic)'. Conducted noise in the present document refers to noise which is carried to the patient by the pneumatic path, such as the air circuit and the patient interface as well as the air therein. In one form, conducted noise may be quantified by measuring sound pressure levels at the end of an air circuit.

[0471] Noise, radiated (acoustic)'. Radiated noise in the present document refers to noise which is carried to the patient by the ambient air. In one form, radiated noise may be quantified by measuring sound power/pressure levels of the object in question according to ISO 3744.

[0472] Noise, vent (acoustic)'. Vent noise in the present document refers to noise which is generated by the flow of air through any vents such as vent holes of the patient interface.

[0473] Oxygen enriched air. Air with a concentration of oxygen greater than that of atmospheric air (21%), for example at least about 50% oxygen, at least about 60% oxygen, at least about 70% oxygen, at least about 80% oxygen, at least about 90% oxygen, at least about 95% oxygen, at least about 98% oxygen, or at least about 99% oxygen. “Oxygen enriched air” is sometimes shortened to “oxygen”.

[0474] Medical Oxygen'. Medical oxygen is defined as oxygen enriched air with an oxygen concentration of 80% or greater.

[0475] Patient'. A person, whether or not they are suffering from a respiratory condition.

[0476] Pressure: Force per unit area. Pressure may be expressed in a range of units, including cmFhO, g-f/cm² and hectopascal. 1 cmFhO is equal to 1 g-f/cm² and 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 cmFhO.

[0477] The pressure in the patient interface is given the symbol Pm, while the treatment pressure, which represents a target value to be achieved by the interface pressure Pm at the current instant of time, is given the symbol Pt.

[0478] 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.

[0479] Ventilator. A mechanical device that provides pressure support to a patient to perform some or all of the work of breathing. 5.6.1.1 Materials & their properties

[0480] Hardness'. Refers to durometer or indentation hardness, which is a material property measured by indentation of an indentor (e.g., as measured in accordance with ASTM D2240).

• ‘Soft’ materials may include silicone or thermo-plastic elastomer (TPE), and may, e.g. readily deform under finger pressure.

• ‘Hard’ materials may include polycarbonate, polypropylene, and may not e.g. readily deform under finger pressure.

[0481] Silicone or Silicone Elastomer. A synthetic rubber. In this specification, a reference to silicone is a reference to liquid silicone rubber (LSR) or a compression moulded silicone rubber (CMSR). One form of commercially available LSR is SILASTIC (included in the range of products sold under this trademark), manufactured by Dow Corning. Another manufacturer of LSR is Wacker. Unless otherwise specified to the contrary, an exemplary form of LSR has a Shore A (or Type A) indentation hardness in the range of about 35 to about 45 as measured using ASTM D2240.

[0482] Polycarbonate', a thermoplastic polymer of Bisphenol-A Carbonate.

5.6.1.2 Mechanics

[0483] Axes: a. Neutral axis'. An axis in the cross-section of a beam or plate along which there are no longitudinal stresses or strains. b. Longitudinal axis'. An axis extending along the length of a shape. The axis generally passes through a center of the shape. c. Circumferential axis'. An axis oriented perpendicularly with respect to the longitudinal axis. The axis may be specifically present in pipes, tubes, cylinders, or similar shapes with a circular and/or elliptical cross section.

[0484] Deformation'. The process where the original geometry of a member changes when subjected to forces, e.g. a force in a direction with respect to an axis. The process may include stretching or compressing, bending and, twisting.

[0485] Elasticity. The ability of a material to return to its original geometry after deformation. [0486] Floppy structure or component: A structure or component that will change shape, e.g. bend, when caused to support its own weight, within a relatively short period of time such as 1 second.

[0487] Resilience-. Ability of a material to absorb energy when deformed elastically and to release the energy upon unloading.

[0488] Resilient-. Will release substantially all of the energy when unloaded. Includes e.g. certain silicones, and thermoplastic elastomers.

[0489] Rigid structure or component: A structure or component that will not substantially change shape when subject to the loads typically encountered in use. An example of such a use may be setting up and maintaining a patient interface in sealing relationship with an entrance to a patient's airways, e.g. at a load of approximately 20 to 30 cmfTO pressure.

[0490] As an example, an I-beam may comprise a different bending stiffness (resistance to a bending load) in a first direction in comparison to a second, orthogonal direction. In another example, a structure or component may be floppy in a first direction and rigid in a second direction.

[0491] Stiffness (or rigidity) of a structure or component: The ability of the structure or component to resist deformation in response to an applied load. The load may be a force or a moment, e.g. compression, tension, bending or torsion. The structure or component may offer different resistances in different directions. The inverse of stiffness is flexibility.

[0492] Viscous: The ability of a material to resist flow.

[0493] Visco-elasticity: The ability of a material to display both elastic and viscous behaviour in deformation.

[0494] Yield: The situation when a material can no longer return back to its original geometry after deformation.

5.6.1.3 Structural Elements

[0495] Compression member: A structural element that resists compression forces.

[0496] Elbow: An elbow is an example of a structure that directs an axis of flow of air travelling therethrough to change direction through an angle. In one form, the angle may be approximately 90 degrees. In another form, the angle may be more, or less than 90 degrees. The elbow may have an approximately circular cross-section. In another form the elbow may have an oval or a rectangular cross- section. In certain forms an elbow may be rotatable with respect to a mating component, e.g. about 360 degrees. In certain forms an elbow may be removable from a mating component, e.g. via a snap connection. In certain forms, an elbow may be assembled to a mating component via a one-time snap during manufacture, but not removable by a patient. [0497] 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.

[0498] 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.

[0499] Tie (noun): A structure designed to resist tension.

[0500] Thin structures: a. Beams, i. A beam may be relatively long in one dimension compared to the other two dimensions such that the smaller dimensions are comparatively thin compared to the long dimension b. Membranes, i. Relatively long in two dimensions, with one thin dimension. Readily deforms in response to bending forces. Resists being stretched, (might also resist compression). c. Plates & Shells i. These may be relatively long in two directions, with one thin dimension. They may have bending, tensile, and/or compressive stiffness.

[0501] Thick structures: Solids

[0502] 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.

[0503] 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.

[0504] 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.

[0505] 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. [0506] Swivel (noun): A subassembly of components configured to rotate about a common axis, preferably independently, preferably under low torque. In one form, the swivel may be constructed to rotate through an angle of at least 360 degrees. In another form, the swivel may be constructed to rotate through an angle less than 360 degrees. When used in the context of an air delivery conduit, the sub-assembly of components preferably comprises a matched pair of cylindrical conduits. There may be little or no leak flow of air from the swivel in use.

5.6.2 Respiratory cycle

[0507] Apnea: According to some definitions, an apnea is said to have occurred when flow falls below a predetermined threshold for a duration, e.g. 10 seconds. An obstructive apnea will be said to have occurred when, despite patient effort, some obstruction of the airway does not allow air to flow. A central apnea will be said to have occurred when an apnea is detected that is due to a reduction in breathing effort, or the absence of breathing effort, despite the airway being patent. A mixed apnea occurs when a reduction or absence of breathing effort coincides with an obstructed airway.

[0508] Breathing rate: The rate of spontaneous respiration of a patient, usually measured in breaths per minute.

[0509] Duty cycle: The ratio of inhalation time, Ti to total breath time, Ttot.

[0510] Effort (breathing): The work done by a spontaneously breathing person attempting to breathe.

[0511] Expiratory portion of a breathing cycle: The period from the start of expiratory flow to the start of inspiratory flow.

[0512] Flow limitation: Flow limitation will be taken to be the state of affairs in a patient's respiration where an increase in effort by the patient does not give rise to a corresponding increase in flow. Where flow limitation occurs during an inspiratory portion of the breathing cycle it may be described as inspiratory flow limitation. Where flow limitation occurs during an expiratory portion of the breathing cycle it may be described as expiratory flow limitation.

[0513] Types of flow limited inspiratory waveforms:

(i) Flattened: Having a rise followed by a relatively flat portion, followed by a fall.

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

(iii) Chair-shaped: Having a single local peak, the peak being at the leading edge, followed by a relatively flat portion.

(iv) Reverse-chair shaped: Having a relatively flat portion followed by single local peak, the peak being at the trailing edge.

[0514] Hypopnea'. According to some definitions, a hypopnea is taken to be a reduction in flow, but not a cessation of flow. In one form, a hypopnea may be said to have occurred when there is a reduction in flow below a threshold rate for a duration. A central hypopnea will be said to have occurred when a hypopnea is detected that is due to a reduction in breathing effort. In one form in adults, either of the following may be regarded as being hypopneas:

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

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

[0515] Hyperpnea'. An increase in flow to a level higher than normal.

[0516] Inspiratory portion of a breathing cycle: The period from the start of inspiratory flow to the start of expiratory flow will be taken to be the inspiratory portion of a breathing cycle.

[0517] Patency (airway): The degree of the airway being open, or the extent to which the airway is open. A patent airway is open. Airway patency may be quantified, for example with a value of one (1) being patent, and a value of zero (0), being closed (obstructed).

[0518] Positive End-Expiratory Pressure PEEP)'. The pressure above atmosphere in the lungs that exists at the end of expiration. [0519] Peak flow rate (Qpeak): The maximum value of flow rate during the inspiratory portion of the respiratory flow waveform.

[0520] Respiratory flow rate, patient airflow rate, respiratory airflow rate (Qr): These terms may be understood to refer to the RPT device’s estimate of respiratory flow rate, as opposed to “true respiratory flow rate” or “true respiratory flow rate”, which is the actual respiratory flow rate experienced by the patient, usually expressed in litres per minute.

[0521] Tidal volume (Vt): The volume of air inhaled or exhaled during normal breathing, when extra effort is not applied. In principle the inspiratory volume Vi (the volume of air inhaled) is equal to the expiratory volume Ve (the volume of air exhaled), and therefore a single tidal volume Vt may be defined as equal to either quantity. In practice the tidal volume Vt is estimated as some combination, e.g. the mean, of the inspiratory volume Vi and the expiratory volume Ve.

[0522] Inhalation Time (Ti): The duration of the inspiratory portion of the respiratory flow rate waveform.

[0523] Exhalation Time (Te) The duration of the expiratory portion of the respiratory flow rate waveform.

[0524] Total Time (Ttot) The total duration between the start of one inspiratory portion of a respiratory flow rate waveform and the start of the following inspiratory portion of the respiratory flow rate waveform.

[0525] Typical recent ventilation-. The value of ventilation around which recent values of ventilation Vent over some predetermined timescale tend to cluster, that is, a measure of the central tendency of the recent values of ventilation.

[0526] Upper airway obstruction (UAO): includes both partial and total upper airway obstruction. This may be associated with a state of flow limitation, in which the flow rate increases only slightly or may even decrease as the pressure difference across the upper airway increases (Starling resistor behaviour).

[0527] Ventilation (Vent): A measure of a rate of gas being exchanged by the patient’s respiratory system. Measures of ventilation may include one or both of inspiratory and expiratory flow, per unit time. When expressed as a volume per minute, this quantity is often referred to as “minute ventilation”. Minute ventilation is sometimes given simply as a volume, understood to be the volume per minute. 5.6.3 Anatomy

5.6.3.1 Anatomy of the face

[0528] Ala: the external outer wall or "wing" of each nostril (plural: alar)

[0529] Alar angle: An angle formed between the ala of each nostril.

[0530] Alare: The most lateral point on the nasal ala.

[0531] Alar curvature (or alar crest) point: The most posterior point in the curved base line of each ala, found in the crease formed by the union of the ala with the cheek.

[0532] Auricle: The whole external visible part of the ear.

[0533] (nose) Bony framework: The bony framework of the nose comprises the nasal bones, the frontal process of the maxillae and the nasal part of the frontal bone. [0534] (nose) Cartilaginous framework: The cartilaginous framework of the nose comprises the septal, lateral, major and minor cartilages.

[0535] Columella: the strip of skin that separates the nares and which runs from the pronasale to the upper lip.

[0536] Columella angle: The angle between the line drawn through the midpoint of the nostril aperture and a line drawn perpendicular to the Frankfort horizontal while intersecting subnasale.

[0537] Frankfort horizontal plane: A line extending from the most inferior point of the orbital margin to the left tragion. The tragion is the deepest point in the notch superior to the tragus of the auricle.

[0538] Glabella: Located on the soft tissue, the most prominent point in the midsagittal plane of the forehead.

[0539] Lateral nasal cartilage: A generally triangular plate of cartilage. Its superior margin is attached to the nasal bone and frontal process of the maxilla, and its inferior margin is connected to the greater alar cartilage.

[0540] Lip, lower (labrale inferius): The lip extending between the subnasale and the mouth.

[0541] Lip, upper (labrale superius): The lip extending between the mouth and the supramenton.

[0542] Greater alar cartilage: A plate of cartilage lying below the lateral nasal cartilage. It is curved around the anterior part of the naris. Its posterior end is connected to the frontal process of the maxilla by a tough fibrous membrane containing three or four minor cartilages of the ala.

[0543] Nares (Nostrils): Approximately ellipsoidal apertures forming the entrance to the nasal cavity. The singular form of nares is naris (nostril). The nares are separated by the nasal septum.

[0544] Naso-labial sulcus or Naso-labial fold: The skin fold or groove that runs from each side of the nose to the comers of the mouth, separating the cheeks from the upper lip.

[0545] Naso-labial angle: The angle between the columella and the upper lip, while intersecting subnasale.

[0546] Otobasion inferior: The lowest point of attachment of the auricle to the skin of the face.

[0547] Otobasion superior: The highest point of attachment of the auricle to the skin of the face.

[0548] Pronasale: the most protruded point or tip of the nose, which can be identified in lateral view of the rest of the portion of the head.

[0549] Philtrum: the midline groove that runs from lower border of the nasal septum to the top of the lip in the upper lip region.

[0550] Pogonion: Located on the soft tissue, the most anterior midpoint of the chin.

[0551] Ridge (nasal): The nasal ridge is the midline prominence of the nose, extending from the Sellion to the Pronasale.

[0552] 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.

[0553] Sellion: Located on the soft tissue, the most concave point overlying the area of the frontonasal suture.

[0554] Septal cartilage (nasal): The nasal septal cartilage forms part of the septum and divides the front part of the nasal cavity.

[0555] Subalare: The point at the lower margin of the alar base, where the alar base joins with the skin of the superior (upper) lip.

[0556] Subnasal point: Located on the soft tissue, the point at which the columella merges with the upper lip in the midsagittal plane. [0557] Supramenton: The point of greatest concavity in the midline of the lower lip between labrale inferius and soft tissue pogonion

[0558] Anatomy of the skull

[0559] Frontal bone: The frontal bone includes a large vertical portion, the squama frontalis, corresponding to the region known as the forehead.

[0560] Mandible: The mandible forms the lower jaw. The mental protuberance is the bony protuberance of the jaw that forms the chin.

[0561] Maxilla: The maxilla forms the upper jaw and is located above the mandible and below the orbits. The frontal process of the maxilla projects upwards by the side of the nose, and forms part of its lateral boundary.

[0562] Nasal bones: The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face, and form, by their junction, the "bridge" of the nose.

[0563] Nasion: The intersection of the frontal bone and the two nasal bones, a depressed area directly between the eyes and superior to the bridge of the nose.

[0564] 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.

[0565] Orbit: The bony cavity in the skull to contain the eyeball.

[0566] Parietal bones: The parietal bones are the bones that, when joined together, form the roof and sides of the cranium.

[0567] 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.

[0568] 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.

5.6.3.2 Anatomy of the respiratory system

[0569] Diaphragm: A sheet of muscle that extends across the bottom of the rib cage. The diaphragm separates the thoracic cavity, containing the heart, lungs and ribs, from the abdominal cavity. As the diaphragm contracts the volume of the thoracic cavity increases and air is drawn into the lungs.

[0570] Larynx: The larynx, or voice box houses the vocal folds and connects the inferior part of the pharynx (hypopharynx) with the trachea.

Ill [0571] Lungs: The organs of respiration in humans. The conducting zone of the lungs contains the trachea, the bronchi, the bronchioles, and the terminal bronchioles. The respiratory zone contains the respiratory bronchioles, the alveolar ducts, and the alveoli.

[0572] Nasal cavity: The nasal cavity (or nasal fossa) is a large air filled space above and behind the nose in the middle of the face. The nasal cavity is divided in two by a vertical fin called the nasal septum. On the sides of the nasal cavity are three horizontal outgrowths called nasal conchae (singular "concha") or turbinates. To the front of the nasal cavity is the nose, while the back blends, via the choanae, into the nasopharynx.

[0573] Pharynx: The part of the throat situated immediately inferior to (below) the nasal cavity, and superior to the oesophagus and larynx. The pharynx is conventionally divided into three sections: the nasopharynx (epipharynx) (the nasal part of the pharynx), the oropharynx (mesopharynx) (the oral part of the pharynx), and the laryngopharynx (hypopharynx).

5.6.4 Patient interface

[0574] 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.

[0575] Headgear: Headgear will be taken to mean a form of positioning and stabilising structure designed to hold a device, e.g., a mask, on a head.

[0576] 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.

[0577] 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.

[0578] 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.

5.6.5 Shape of structures

[0579] Products in accordance with the present technology may comprise one or more three-dimensional mechanical structures, for example a mask cushion or an impeller. The three-dimensional structures may be bounded by two-dimensional surfaces. These surfaces may be distinguished using a label to describe an associated surface orientation, location, function, or some other characteristic. For example a structure may comprise one or more of an anterior surface, a posterior surface, an interior surface and an exterior surface. In another example, a seal-forming structure may comprise a face-contacting (e.g. outer) surface, and a separate non-face- contacting (e.g. underside or inner) surface. In another example, a structure may comprise a first surface and a second surface.

[0580] To facilitate describing the shape of the three-dimensional structures and the surfaces, we first consider a cross-section through a surface of the structure at a point, p. See Fig. 3B to Fig. 3F, which illustrate examples of cross-sections at point p on a surface, and the resulting plane curves. Figs. 3B to 3F also illustrate an outward normal vector at p. The outward normal vector at p points away from the surface. In some examples we describe the surface from the point of view of an imaginary small person standing upright on the surface.

5.6.5.1 Curvature in one dimension

[0581] The curvature of a plane curve at p may be described as having a sign (e.g. positive, negative) and a magnitude (e.g. 1/radius of a circle that just touches the curve at p).

[0582] Positive curvature: If the curve at p turns towards the outward normal, the curvature at that point will be taken to be positive (if the imaginary small person leaves the point p they must walk uphill). See Fig. 3B (relatively large positive curvature compared to Fig. 3C) and Fig. 3C (relatively small positive curvature compared to Fig. 3B). Such curves are often referred to as concave.

[0583] Zero curvature: If the curve at p is a straight line, the curvature will be taken to be zero (if the imaginary small person leaves the point p, they can walk on a level, neither up nor down). See Fig. 3D. [0584] Negative curvature: If the curve at p turns away from the outward normal, the curvature in that direction at that point will be taken to be negative (if the imaginary small person leaves the point p they must walk downhill). See Fig. 3E (relatively small negative curvature compared to Fig. 3F) and Fig. 3F (relatively large negative curvature compared to Fig. 3E). Such curves are often referred to as convex.

5.6.5.2 Curvature of two dimensional surfaces

[0585] A description of the shape at a given point on a two-dimensional surface in accordance with the present technology may include multiple normal crosssections. The multiple cross-sections may cut the surface in a plane that includes the outward normal (a “normal plane”), and each cross-section may be taken in a different direction. Each cross-section results in a plane curve with a corresponding curvature. The different curvatures at that point may have the same sign, or a different sign. Each of the curvatures at that point has a magnitude, e.g. relatively small. The plane curves in Figs. 3B to 3F could be examples of such multiple cross-sections at a particular point.

[0586] Principal curvatures and directions: The directions of the normal planes where the curvature of the curve takes its maximum and minimum values are called the principal directions. In the examples of Fig. 3B to Fig. 3F, the maximum curvature occurs in Fig. 3B, and the minimum occurs in Fig. 3F, hence Fig. 3B and Fig. 3F are cross sections in the principal directions. The principal curvatures at p are the curvatures in the principal directions.

[0587] Region of a surface: A connected set of points on a surface. The set of points in a region may have similar characteristics, e.g. curvatures or signs.

[0588] Saddle region: A region where at each point, the principal curvatures have opposite signs, that is, one is positive, and the other is negative (depending on the direction to which the imaginary person turns, they may walk uphill or downhill).

[0589] Dome region: A region where at each point the principal curvatures have the same sign, e.g. both positive (a “concave dome”) or both negative (a “convex dome”).

[0590] Cylindrical region: A region where one principal curvature is zero (or, for example, zero within manufacturing tolerances) and the other principal curvature is non-zero. [0591] Planar region: A region of a surface where both of the principal curvatures are zero (or, for example, zero within manufacturing tolerances).

[0592] Edge of a surface: A boundary or limit of a surface or region.

[0593] Path: In certain forms of the present technology, ‘path’ will be taken to mean a path in the mathematical - topological sense, e.g. a continuous space curve from f(0) to f(l) on a surface. In certain forms of the present technology, a ‘path’ may be described as a route or course, including e.g. a set of points on a surface. (The path for the imaginary person is where they walk on the surface, and is analogous to a garden path).

[0594] Path length: In certain forms of the present technology, ‘path length’ will be taken to mean the distance along the surface from f(0) to f( 1 ), that is, the distance along the path on the surface. There may be more than one path between two points on a surface and such paths may have different path lengths. (The path length for the imaginary person would be the distance they have to walk on the surface along the path).

[0595] Straight-line distance: The straight-line distance is the distance between two points on a surface, but without regard to the surface. On planar regions, there would be a path on the surface having the same path length as the straight-line distance between two points on the surface. On non-planar surfaces, there may be no paths having the same path length as the straight-line distance between two points. (For the imaginary person, the straight-line distance would correspond to the distance ‘as the crow flies’.)

5.6.5.3 Space curves

[0596] Space curves: Unlike a plane curve, a space curve does not necessarily lie in any particular plane. A space curve may be closed, that is, having no endpoints. A space curve may be considered to be a one-dimensional piece of three-dimensional space. An imaginary person walking on a strand of the DNA helix walks along a space curve. A typical human left ear comprises a helix, which is a left-hand helix, see Fig. 3Q. A typical human right ear comprises a helix, which is a right-hand helix, see Fig. 3R. Fig. 3S shows a right-hand helix. The edge of a structure, e.g. the edge of a membrane or impeller, may follow a space curve. In general, a space curve may be described by a curvature and a torsion at each point on the space curve. Torsion is a measure of how the curve turns out of a plane. Torsion has a sign and a magnitude. The torsion at a point on a space curve may be characterised with reference to the tangent, normal and binormal vectors at that point.

[0597] Tangent unit vector (or unit tangent vector): For each point on a curve, a vector at the point specifies a direction from that point, as well as a magnitude. A tangent unit vector is a unit vector pointing in the same direction as the curve at that point. If an imaginary person were flying along the curve and fell off her vehicle at a particular point, the direction of the tangent vector is the direction she would be travelling.

[0598] Unit normal vector: As the imaginary person moves along the curve, this tangent vector itself changes. The unit vector pointing in the same direction that the tangent vector is changing is called the unit principal normal vector. It is perpendicular to the tangent vector.

[0599] Binormal unit vector: The binormal unit vector is perpendicular to both the tangent vector and the principal normal vector. Its direction may be determined by a right-hand rule (see e.g. Fig. 3P), or alternatively by a left-hand rule (Fig. 30). [0600] Osculating plane: The plane containing the unit tangent vector and the unit principal normal vector. See Figures 30 and 3P.

[0601] Torsion of a space curve: The torsion at a point of a space curve is the magnitude of the rate of change of the binormal unit vector at that point. It measures how much the curve deviates from the osculating plane. A space curve which lies in a plane has zero torsion. A space curve which deviates a relatively small amount from the osculating plane will have a relatively small magnitude of torsion (e.g. a gently sloping helical path). A space curve which deviates a relatively large amount from the osculating plane will have a relatively large magnitude of torsion (e.g. a steeply sloping helical path). With reference to Fig. 3S, since T2>T1, the magnitude of the torsion near the top coils of the helix of Fig. 3S is greater than the magnitude of the torsion of the bottom coils of the helix of Fig. 3S

[0602] With reference to the right-hand rule of Fig. 3P, a space curve turning towards the direction of the right-hand binormal may be considered as having a righthand positive torsion (e.g. a right-hand helix as shown in Fig. 3S). A space curve turning away from the direction of the right-hand binormal may be considered as having a right-hand negative torsion (e.g. a left-hand helix). [0603] Equivalently, and with reference to a left-hand rule (see Fig. 30), a space curve turning towards the direction of the left-hand binormal may be considered as having a left-hand positive torsion (e.g. a left-hand helix). Hence left-hand positive is equivalent to right-hand negative. See Fig. 3T.

5.6.5.4 Holes

[0604] A surface may have a one-dimensional hole, e.g. a hole bounded by a plane curve or by a space curve. Thin structures (e.g. a membrane) with a hole, may be described as having a one-dimensional hole. See for example the one dimensional hole in the surface of structure shown in Fig. 31, bounded by a plane curve.

[0605] A structure may have a two-dimensional hole, e.g. a hole bounded by a surface. For example, an inflatable tyre has a two dimensional hole bounded by the interior surface of the tyre. In another example, a bladder with a cavity for air or gel could have a two-dimensional hole. See for example the cushion of Fig. 3E and the example cross-sections therethrough in Fig. 3M and Fig. 3N, with the interior surface bounding a two dimensional hole indicated. In a yet another example, a conduit may comprise a one-dimension hole (e.g. at its entrance or at its exit), and a two-dimension hole bounded by the inside surface of the conduit. See also the two dimensional hole through the structure shown in Fig. 3K, bounded by a surface as shown.

5.7 OTHER REMARKS

[0606] 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.

[0607] 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. [0608] 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.

[0609] Furthermore, “approximately”, “substantially”, “about”, or any similar term used herein means +/- 5-10% of the recited value.

[0610] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this technology belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present technology, a limited number of the exemplary methods and materials are described herein.

[0611] 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.

[0612] 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.

[0613] 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.

[0614] 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. [0615] 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.

[0616] Although the technology herein has been described with reference to particular examples, it is to be understood that these examples are merely illustrative of the principles and applications of the technology. In some instances, the terminology and symbols may imply specific details that are not required to practice the technology. For example, although the terms "first" and "second" may be used, unless otherwise specified, they are not intended to indicate any order but may be utilised to distinguish between distinct elements. Furthermore, although process steps in the methodologies may be described or illustrated in an order, such an ordering is not required. Those skilled in the art will recognize that such ordering may be modified and/or aspects thereof may be conducted concurrently or even synchronously.

[0617] 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, the technology.

5.8 REFERENCE SIGNS LIST

Claims

6 CLAIMS We claim:

1. A headgear connector comprising: a retainer including a first engagement structure, the retainer being configured to connect to a patient interface; and a clip including a second engagement structure, the clip being configured to connect to a strap of the patient interface, wherein one of the first engagement structure or the second engagement structure includes a female engagement structure, wherein the other of the first engagement and the second engagement structure includes a male engagement structure, wherein the male engagement structure includes a post projecting out from a surface and a plurality of deflectable prongs projecting out from the surface and positioned around the post, wherein the female engagement structure includes a receiver defining an opening, wherein the headgear connector is configured to transition between an engaged state in which the clip is coupled to the retainer and a disengaged state in which the clip is uncoupled from the retainer, and wherein, in the engaged state, the male engagement structure is received within the female engagement structure.

2. The headgear connector of claim 1, wherein the retainer includes the male engagement structure, and the clip includes the female engagement structure.

3. The headgear connector of claim 1 or 2, wherein the opening of the receiver extends completely through a first surface and a second surface, opposite the first surface.

4. The headgear connector of any one of claims 1-3, wherein the male engagement structure has a height that is greater than a height of the opening so that the male engagement structure extends through the opening in the engaged state.

5. The headgear connector of claims 1 or 2, wherein the opening of the receiver extends through a first surface and terminates prior to a second surface, opposite the first surface.

6. The headgear connector of any one of claims 1-5, wherein the male engagement structure includes two, three, or four deflectable prongs projecting out from the surface and surrounding the post.

7. The headgear connector of any one of claims 1-6, wherein transitioning to the engaged state requires a force of about 1.0N to about 30.0N.

8. The headgear connector of any one of claims 1-7, wherein transitioning from the engaged state to the disengaged state requires a force of about 1.0N to about 60.0N.

9. The headgear connector of any one of claims 1-8, wherein the receiver has a first receiver surface, a second receiver surface, and a receiver transition located between the first receiver surface and the second receiver surface, wherein the receiver transition protrudes further into the opening of the receiver compared to the first receiver surface and the second receiver surface.

10. The headgear connector of any one of claims 1-9, wherein each of the plurality of prongs includes an outwardly protruding ridge on a side of the prong facing away from the post.

11. The headgear connector of any one of claims 1 to 8, wherein: the receiver has a first receiver surface, a second receiver surface, and a receiver transition located between the first receiver surface and the second receiver surface, wherein the receiver transition protrudes further into the opening of the receiver compared to the first receiver surface and the second receiver surface, each of the plurality of prongs includes an outwardly protruding ridge on a side of the prong facing away from the post, and when transitioning the headgear connector to the engaged state, the outwardly protruding ridge on each of the plurality of prongs contacts the receiver transition as the male engagement structure is received within the female engagement structure, causing the plurality of prongs to deflect inwards towards the post.

12. The headgear connector of claim 11, wherein the outwardly protruding ridge of each of the plurality of prongs is located further into the receiver than the receiver transition in the engaged state.

13. The headgear connector of any one of claims 1-12, wherein the retainer is removably coupled to the patient interface.

14. The headgear connector of any one of claims 1-13, wherein the clip is removably coupled to the strap of the patient interface.

15. The headgear connector of any one of claims 1-14, wherein at least one of the clip and the retainer includes at least one of dimples, bumps, grooves, recesses, serrations, ridges, knurling, or texturing on a portion configured to be contacted by a patient.

16. A patient interface comprising: a headgear including a first strap and a second strap; a seal forming structure; and the headgear connector of any one of claims 1 to 15.

17. The patient interface of claim 16, further including a positioning and stabilizing frame detachably connected to the seal forming structure, the frame a pair of upper arms and a pair of lower arms including the male engagement structure.

18. A headgear connector, comprising: a retainer including a male engagement structure, the retainer being configured to connect to a patient interface; and a clip including a female engagement structure, the clip being configured to connect to a strap of the patient interface, wherein the female engagement structure includes a receiver defining an opening, the receiver having a first receiver surface, a second receiver surface, and a receiver transition located between the first receiver surface and the second receiver surface, wherein the male engagement structure includes a post and a plurality of deflectable prongs encircling the post, each of the plurality of prongs having an outwardly protruding ridge on a side facing away from the post, and wherein the outwardly protruding ridges of the plurality of prongs encircling the post form an imaginary circle having a diameter that is greater than a diameter of the opening at the receiver transition.

19. The headgear connector of claim 18, wherein the opening of the receiver extends through opposite surfaces of the clip.

20. The headgear connector of claim 18 or 19, wherein the male engagement structure includes two, three, or four deflectable prongs.

21. A patient interface comprising: a headgear including a first strap and a second strap; a seal forming structure; and a pair of the headgear connector of any one of claims 18 to 20, the clip being configured to connect to at least one of the first strap or the second strap.

22. The patient interface of claim 21, further including a positioning and stabilizing frame detachably connected to the seal forming structure, the frame including the male engagement structure.