Patient interface with variable thickness seal-forming structure

Abstract

To provide a medical device used in the diagnosis, amelioration, treatment or prevention of respiratory disorders having one or more of improved comfort, cost, efficacy, ease of use, and manufacturability.SOLUTION: A cushion assembly for a patient interface includes an elastomeric support portion and an elastomeric seal-forming structure supported by the elastomeric support portion that is more rigid than the elastomeric seal-forming structure. The elastomeric seal-forming structure includes a first compliant region and a second compliant region that is separated from the first compliant region by a support region that is more rigid than the first and second compliant regions. The more rigid support region extends to and is anchored by the elastomeric support portion. In addition, for every point in the rigid support region, the inner surface has a negative curvature when the outer surface has a positive curvature, and the inner surface has a positive curvature when the outer surface has a negative curvature.SELECTED DRAWING: Figure 27A

Description

[Technical field]

[0001] 1 CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62 / 222,503, filed September 23, 2015, Published Patent Application No. AU2016 / 050228, filed March 24, 2016, and U.S. Provisional Patent Application No. 62 / 377,158, filed August 19, 2016, each of which is incorporated by reference in its entirety.

[0002] 2. Technology Background

[0003] 2.1 Technology field

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

[0005] 2.2 Description of Related Art

[0006] 2.2.1 The human respiratory system and its diseases

[0007] The body's respiratory system facilitates gas exchange. The nose and oral cavity form the entrance to a patient's airways.

[0008] These airways contain a series of branching tubes that become narrower, shorter and more numerous the deeper they go into the lungs. The primary function of the lungs is gas exchange, allowing oxygen to enter the venous blood from the air and carbon dioxide to leave. The trachea divides into right and left main bronchi, which further divide into terminal bronchioles. The bronchi constitute the conducting airways and do not participate in gas exchange. The airways further divide into respiratory bronchioles and finally into alveoli. Gas exchange occurs in the alveolar region of the lungs, which is called the respiratory zone. See: "Respiratory Physiology", by John B. West, Lippincott Williams & Wilkins, 9th edition published 2012.

[0009] There is a range of respiratory diseases. Particular diseases can be characterized by particular manifestations such as apnea, hypopnea and hyperpnea.

[0010] Examples of respiratory diseases include obstructive sleep apnea (OSA), Cheyne-Stokes respiration (CSR), respiratory failure, obesity hyperventilation syndrome (OHS), chronic obstructive pulmonary disease (COPD), neuromuscular diseases (NMD) and chest wall diseases.

[0011] Obstructive sleep apnea (OSA) is a form of sleep-disordered breathing (SDB) characterized by episodes of closure or obstruction of the upper airway during sleep. It is due to a combination of normal loss of muscle tone in the area of ​​the abnormally small upper airway and tongue, soft palate and posterior oropharyngeal wall during sleep. The condition causes affected patients to pause breathing, typically for 30-120 seconds, sometimes as many as 200-300 times per night. This results in excessive daytime sleepiness, which can lead to cardiovascular disease and brain damage. The condition is common, especially in middle-aged, overweight men, but patients are asymptomatic. See U.S. Pat. No. 4,944,310 (Sullivan).

[0012] Cheyne-Stokes respiration (CSR) is another form of sleep-disordered breathing. CSR is a disease of the patient's respiratory regulator, followed by alternating periods of waxing and waning of ventilation, known as the CSR cycle. CSR is characterized by repeated deoxygenation and reaeration of arterial blood. Because of the repeated hypoxia, CSR can be harmful. In some patients, CCR is accompanied by recurrent sleep arousals that cause severe insomnia, increased sympathetic activity, and increased afterload. See U.S. Patent No. 6,532,959 (Berthon-Jones).

[0013] Respiratory failure is a general term for respiratory disorders that refers to the inability of the lungs to take in enough oxygen or breathe out enough CO2 to meet the patient's needs. Respiratory failure can include some or all of the following conditions:

[0014] Patients with respiratory failure (a type of respiratory insufficiency) may experience abnormal shortness of breath during exercise.

[0015] Obesity hyperventilation syndrome (OHS) is defined as the combination of severe obesity and chronic awake hypercapnia in the absence of any other clear cause of hypoventilation. Symptoms include dyspnea, morning headache, and excessive daytime sleepiness.

[0016] Chronic obstructive pulmonary disease (COPD) encompasses any of a group of lower airway diseases that share certain common characteristics. These include increased resistance to air movement, prolongation of the expiratory phase of breathing, and a decrease in the normal elasticity of the lungs. Examples of COPD include emphysema and chronic bronchitis. Causes of COPD include chronic smoking (the primary risk factor), occupational exposure, air pollution, and genetic factors. Symptoms include dyspnea on exertion, chronic cough, and sputum production.

[0017] Neuromuscular diseases (NMD) is a broad term that encompasses numerous diseases and illnesses that impair muscle function directly through intrinsic muscle pathology or indirectly through neuropathology. Some NMD patients are characterized by progressive muscle damage, resulting in inability to walk, wheelchair confinement, difficulty swallowing, respiratory muscle weakness, and ultimately death due to respiratory failure. Neuromuscular disorders can be classified as rapidly and slowly progressive: (i) rapidly progressive disorders, characterized by muscle damage that worsens over months and leads to death within a few years (e.g., amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers); (ii) variable or slowly progressive disorders, characterized by muscle damage that worsens over years and only slightly reduces life expectancy (e.g., limb-girdle, facioscapulohumeral, and myotonic muscular dystrophies). Symptoms of respiratory failure in NMD include: increasing generalized weakness, difficulty swallowing, dyspnea on exertion and at rest, fatigue, drowsiness, morning headache, and difficulty concentrating and mood changes.

[0018] Chest wall disorders are a group of thoracic deformities that result in ineffective connections between the respiratory muscles and the rib cage. These disorders are primarily characterized by restrictive defects and share the potential for long-term hypercapnic respiratory failure. Scoliosis and / or kyphoscoliosis can lead to severe respiratory failure. Symptoms of respiratory failure include: dyspnea on exertion, peripheral edema, orthopnea, recurrent chest infections, morning headache, fatigue, poor quality of sleep, and loss of appetite.

[0019] A range of treatments are available to treat or ameliorate such conditions, and otherwise healthy individuals may also benefit from preventative treatments for respiratory disease, but these suffer from a number of deficiencies.

[0020] 2.2.2 Treatment

[0021] A variety of therapies are used to treat one or more of the above respiratory disorders, including continuous positive airway pressure (CPAP) therapy, non-invasive ventilation (NIV) and invasive ventilation (IV).

[0022] Continuous positive airway pressure (CPAP) therapy has been used in the treatment of obstructive sleep apnea (OSA). Its mechanism of action is that it acts as a pneumatic splint, for example by pushing the soft palate and tongue forward or backward against the posterior oropharyngeal wall, thereby preventing the closure of the upper airway. Because the treatment of OSA with CPAP therapy can be voluntary, patients may choose not to comply with treatment if they perceive one or more of the following from the device used to deliver the treatment: uncomfortable, difficult to use, expensive, or aesthetically unappealing.

[0023] Non-invasive ventilation (NIV) provides ventilatory support to a patient through the upper airway to assist in breathing by performing some or all of the respiratory functions and / or to maintain adequate oxygen levels in the body. Ventilatory support is provided through a non-invasive patient interface. NIV is used to treat forms of CSR and respiratory failure such as OHS, COPD, NMD, and chest wall disorders. In some forms, it may improve the comfort and effectiveness of these treatments.

[0024] Invasive ventilation (IV) provides ventilatory support to patients who can no longer breathe effectively on their own and may be provided using a tracheotomy tube. In some forms, the comfort and effectiveness of these treatments may be improved.

[0025] 2.2.3 Treatment system

[0026] These therapies may be provided by a therapeutic system or device. Such systems and devices may also be used to diagnose conditions without treating them.

[0027] The treatment system may include a respiratory pressure treatment device (RPT device), an air circuit, a humidifier, a patient interface, and data management.

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

[0029] 2.2.3.1 Patient Interface

[0030] The patient interface may be used to provide the wearer with an interface to the respiratory appliance, for example by providing airflow to the airway entrance. Airflow may be provided via a mask to the nose and / or mouth, a tube to the mouth, or a tracheotomy tube to the patient's trachea. Depending on the therapy being applied, the patient interface may form a seal, for example with an area of ​​the patient's face, to facilitate gas delivery at a pressure of sufficient dispersion with ambient pressure for therapy to be performed (e.g., at a positive pressure of about 10 cmH2O relative to ambient pressure). In other forms of therapy, such as oxygen delivery, the patient interface may not include a seal sufficient to facilitate delivery of a gas supply to the airway at a positive pressure of about 10 cmH2O.

[0031] Certain other mask systems may be functionally inadequate in the field, for example masks that are purely decorative may not be able to maintain adequate pressure, mask systems used for underwater swimming or diving may be configured to protect against water intrusion from higher external pressures and not maintain internal air at pressures higher than ambient.

[0032] Certain masks may be clinically unsuitable for use with this technology (eg, if the mask blocks airflow through the nose and only allows airflow through the mouth).

[0033] In certain masks, where the patient must insert part of the mask structure into their mouth and create and maintain a seal via the lips, this may be uncomfortable or impractical in the art.

[0034] Certain masks may be impractical for use while sleeping (eg, when sleeping on one's side in bed with head on a pillow).

[0035] There are several challenges in designing a patient interface: The face has a complex three-dimensional shape. The size and shape of the nose and head vary greatly between individuals. Because the head contains bone, cartilage and soft tissue, different regions of the face respond differently to mechanical forces; i.e., the chin or mandible may move relative to other bones of the skull. The entire head may move throughout the respiratory treatment period.

[0036] These challenges may result in one or more of the following: some masks may be intrusive, aesthetically undesirable, costly, poor fit, difficult to use, and uncomfortable, especially if the wear time is long or the patient is unfamiliar with the system. If the wrong size mask is used, this may lead to poor fit, poor comfort, and poor patient outcomes. While masks designed specifically for aviators, as part of personal protective equipment (e.g., filter masks), SCUBA masks, or anesthesia administration masks may be tolerable for their intended use, such masks may be undesirably uncomfortable to wear for extended periods of time (e.g., several hours). Such discomfort may result in poor patient compliance with treatment. This is especially true if the mask must be worn while sleeping.

[0037] CPAP therapy is highly effective in treating certain respiratory conditions if the patient complies with the therapy. If the mask is uncomfortable or difficult to use, the patient may not comply with the therapy. Because patients are often encouraged to clean their masks regularly, if the mask is difficult to clean (e.g., difficult to assemble or disassemble), the patient may not be able to clean the mask, which may affect patient compliance.

[0038] Masks for other uses (e.g., for aviators) may be unsuitable for use in treating sleep-disordered breathing, and masks designed for use in treating sleep-disordered breathing may be suitable for other uses.

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

[0040] 2.2.3.1.1 Seal-forming parts

[0041] The patient interface may include a seal-forming portion. Because the patient interface is in direct contact with the patient's face, the shape and configuration of the seal-forming portion may have a direct impact on the effectiveness and comfort of the patient interface.

[0042] The patient interface may be characterized in part according to the design intent of where the seal-forming portion engages the face in use. In one form of the patient interface, the seal-forming portion may include a first sub-portion for forming a seal around the left nostril and a second sub-portion for forming a seal around the right nostril. In one form of the patient interface, the seal-forming portion may include a single element that encloses both nostrils in use. Such a single element may be designed to rest, for example, on the upper lip region and nasal bridge region of the face. In one form of the patient interface, the seal-forming portion may include an element that encloses the oral cavity region in use, for example by forming a seal on the lower lip region of the face. In one form of the patient interface, the seal-forming portion may include a single element that encloses both nostrils and the oral cavity region in use. These different types of patient interfaces may be known by various names by their manufacturers, such as nasal masks, full face masks, nasal pillows, nasal puffs, and oronasal masks.

[0043] A seal-forming portion that may be effective in one area of ​​a patient's face may be inadequate in another area, for example, due to different shapes, structures, variability, and sensitive areas of the patient's face. For example, the seal of swim goggles that rests on the patient's forehead may be inadequate for use on the patient's nose.

[0044] A particular seal-forming portion may be designed for mass production so that one design will fit, be comfortable, and be effective for a wide range of different face shapes and sizes. To the extent there is a mismatch between the shape of the patient's face and the seal-forming portion of the mass-produced patient interface, one or both may need to be adapted in order to form a seal.

[0045] One type of seal-forming portion 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 portion engaged against the patient's face. This seal-forming portion may include an air or fluid filled cushion, or may include a molded or formed surface of a resilient sealing element comprised of an elastomer such as rubber. With this type of seal-forming portion, if the fit is improper, a gap will occur between the seal-forming portion and the face, and additional force will be required to press the patient interface against the face to achieve a seal.

[0046] Another type of seal-forming portion uses a thin flap seal that is placed around the periphery of the mask to provide a self-sealing action against the patient's face when positive pressure is applied within the mask. As with the previous type of seal-forming portion, if the fit between the face and the mask is poor, additional force may be required to achieve a seal or the mask may leak. Additionally, if the shape of the seal-forming portion does not match the shape of the patient, the seal-forming portion may fold or buckle during use, causing leakage.

[0047] Other types of seal-forming parts may include friction-fit elements that are inserted into the nostrils, for example, but some patients find these seal-forming parts uncomfortable.

[0048] Another form of seal-forming portion may use adhesives to achieve a seal. Some patients find it inconvenient to constantly apply and remove adhesives from their face.

[0049] A range of patient interface seal forming techniques are disclosed in the following patent applications (assigned to ResMed Limited: WO1998 / 004,310; WO2006 / 074,513; WO2010 / 135,785).

[0050] One form of nasal pillow is found in the Adam line manufactured by Puritan Bennett. Another nasal pillow or nasal puff is the subject of U.S. Patent No. 4,782,832 (Trimble et al.), assigned to the Puritan-Bennett Corporation.

[0051] ResMed Limited manufactures the following products that use nasal pillows: SWIFT® Nasal Pillows Mask, SWIFT® II Nasal Pillows Mask, SWIFT® LT Nasal Pillows Mask, SWIFT® FX Nasal Pillows Mask and MIRAGELIBERTY® Full Face Mask. Embodiments of nasal pillows masks are described in the following patent applications assigned to ResMed Limited: International Patent Application WO 2004 / 073,778 (which describes, among other things, aspects of ResMed Limited's SWIFT® nasal pillows); U.S. Patent Application No. 2009 / 0044808 (which describes, among other things, aspects of ResMed Limited's SWIFT® LT nasal pillows); International Patent Applications WO 2005 / 063,328 and WO 2006 / 130,903 (which describe, among other things, aspects of ResMed Limited's MIRAGE LIBERTY® full face mask); and International Patent Application WO 2009 / 052,560 (which describes, among other things, aspects of ResMed Limited's SWIFT® FX nasal pillows).

[0052] 2.2.3.1.2 Positioning and stabilization

[0053] Seal-forming portions of patient interfaces used in positive air therapy experience corresponding forces from the air pressure that disrupt the seal, so a variety of techniques are used to position the seal-forming portions and maintain a seal against the appropriate portion of the face.

[0054] In one technique, adhesives are used, see, for example, U.S. Patent Application Publication US2010 / 0000534, but adhesives can be uncomfortable.

[0055] Another technique involves the use of one or more straps and / or stabilizing harnesses, many of which suffer from one or more of the following problems: poor fit, bulkiness, discomfort and awkwardness.

[0056] 2.2.3.2 Respiratory Pressure Therapy (RPT) Devices

[0057] Respiratory pressure therapy (RPT) devices can be used to deliver one or more of the above therapies, for example, by generating an air delivery flow to the airway inlet. This air flow can be pressurized. Examples of RPT devices include CPAP devices and mechanical ventilators.

[0058] Air pressure generators are known in a wide range of applications (e.g., industrial-scale ventilation systems). However, air pressure generators for medical applications have specific requirements that cannot be met by more common air pressure generators (e.g., medical equipment reliability, size, and weight requirements). In addition, even devices designed for medical treatment may suffer from deficiencies related to one or more of the following: comfort, noise, ease of use, effectiveness, size, weight, manufacturability, cost, and reliability.

[0059] One example of a special requirement of a particular RPT device is acoustic noise.

[0060] [Table 1]

[0061] One known RPT device used to treat sleep-disordered breathing is the S9 Sleep Therapy System (manufactured by ResMed Limited). Another example of an RPT device is a ventilator. Ventilators (e.g., the ResMed Stellar® series of adult and pediatric ventilators) can provide invasive and non-invasive independent breathing support for patients for a range of conditions (including, but not limited to, NMD, OHS, and COPD).

[0062] The ResMed Elisee® 150 ventilator and ResMed VSIII® ventilators can provide invasive and non-invasive dependent respiratory support suitable for adult or pediatric patients for the treatment of multiple conditions. These ventilators provide volumetric and pressure ventilation modes with single or dual limb circuits. RPT devices typically include a pressure generator (e.g., a motorized blower or compressed gas reservoir) and are configured to deliver airflow to the patient's airway. In some cases, the airflow can be delivered at positive pressure to the patient's airway. The outlet of the RPT device is connected via an air circuit to a patient interface as described above.

[0063] A device designer may be presented with a myriad of choices. Often, design criteria conflict, making certain design choices unconventional or unavoidable. Furthermore, the comfort and effectiveness of a particular embodiment may be significantly affected by minor changes in one or more parameters.

[0064] 2.2.3.3 Humidifier

[0065] Delivery of airflow without humidification can lead to drying of the airway. When a humidifier is used with the RPT device and patient interface, humidified gas is produced, minimizing drying of the nasal mucosa and increasing comfort of the patient airway. Additionally, in cooler climates, the application of warm air to the facial area surrounding the patient interface generally provides more comfort than cool air.

[0066] A range of artificial humidification devices and systems are known, but do not meet the special requirements of medical humidifiers.

[0067] Medical humidifiers are typically used when a patient is sleeping or resting (e.g., in a hospital) to increase the humidity and / or temperature of the air stream relative to the ambient air when necessary. Bedside medical humidifiers may be small. Medical humidifiers may be configured to only humidify and / or heat the air stream delivered to the patient, and not the patient's surroundings. For example, room-based systems (e.g., saunas, air conditioners, or evaporative coolers) may also humidify the air breathed into the patient's body, but these systems also humidify and / or heat the entire room, which may be uncomfortable for occupants. Additionally, medical humidifiers may have more stringent safety constraints than industrial humidifiers.

[0068] Although a number of medical humidifiers are known, such medical humidifiers may suffer from one or more deficiencies, i.e., some of such medical humidifiers provide inadequate humidification and others are difficult or inconvenient for the patient to use.

[0069] 2.2.3.4 Data Management

[0070] For clinical reasons, data may be obtained to determine whether a patient prescribed respiratory treatment is "compliant" (e.g., whether the patient follows a particular "compliance rule" with their RPT device). One example of a compliance rule for CPAP treatment is that a patient must use the RPT device for at least 4 hours per night for at least 21 days out of 30 consecutive days to be considered compliant. To determine patient compliance, a provider of the RPT device (e.g., a healthcare provider) may manually obtain data describing the patient's treatment with the RPT device, calculate a usage rate over a period of time, and compare this to the compliance rule. Once the healthcare provider determines that the patient has used their RPT device in accordance with the compliance rule, the healthcare provider may notify a third party that the patient is compliant.

[0071] There may be other aspects of a patient's care that would benefit from communication of treatment data to third parties or external systems.

[0072] Existing processes for communicating and managing such data can be one or more of: costly, time consuming, and error prone.

[0073] 2.2.3.5 Mandibular repositioning

[0074] Mandibular repositioning devices (MRDs) or mandibular advancement devices (MADs) are a treatment option for sleep apnea and snoring. They are adjustable oral appliances available from dentists or other suppliers that hold the mandible (lower jaw) in an anterior position during sleep. MRDs are removable devices that are inserted into the oral cavity before the patient sleeps and removed afterwards. As such, MRDs are not designed for full-time wear. MRDs may be custom made or manufactured in standard forms and include bite impression sites designed to fit the patient's teeth. This mechanical protrusion from the mandible expands the space behind the tongue and applies tension on the pharyngeal walls to reduce airway collapse and reduce palate vibration.

[0075] In certain examples, the mandibular advancement device may include an upper splint intended to engage or mate with teeth on the upper jaw or maxilla, and a lower splint intended to engage or mate with teeth on the upper jaw or mandible. The upper and lower splints are laterally connected to each other via a pair of connecting rods that are fixed symmetrically on the upper and lower splints.

[0076] In such a design, the length of the connecting rod is selected so that the mandible is held in an anterior position when the MRD is placed in the patient's mouth. The length of the connecting rod can be adjusted to vary the level of protrusion of the mandible. The dentist can determine the level of protrusion required for the mandible, which in turn determines the length of the connecting rod.

[0077] Some MRDs are configured to push the mandible forward relative to the maxilla, while others, such as the ResMed Narval CC® MRD, are designed to hold the mandible in an anterior position. The device also reduces or minimizes dental and temporomandibular joint (TMJ) side effects. As such, the device is configured to minimize or avoid any movement of one or more of the teeth.

[0078] 2.2.3.6 Ventilation technology

[0079] Some forms of treatment systems may include a vent to push out exhaled carbon dioxide, which may allow flow from an interior space of the patient interface (e.g., a plenum chamber) to an exterior of the patient interface (e.g., the surroundings).

[0080] The vent may include an orifice through which gas may flow when the mask is in use. Many such vents are noisy. Others may become blocked when in use, resulting in insufficient pumping. Some vents may disrupt sleep for the patient 1000 and bed companion 1100, for example, due to noise or airflow concentration.

[0081] ResMed Limited has developed several improved mask ventilation technologies, see International Patent Application Publication No. WO1998 / 034,665; International Patent Application Publication No. WO2000 / 078,381; U.S. Patent No. 6,581,594; U.S. Patent Application Publication No. US2009 / 0050156; U.S. Patent Application Publication No. 2009 / 0044808.

[0082] [Table 2]

[0083] [Table 3]

[0084] 2.2.4 Diagnostic and Monitoring Systems

[0085] Polysomnography (PSG) is a conventional system for diagnosing and monitoring cardiopulmonary diseases, which typically requires expert clinical staff for system application. In PSG, typically 15-20 contact sensors are placed on the human body to record various body signals (e.g., electroencephalography (EEG), electrocardiography (ECG), electrooculography (EOG), electromyography (EMG)). For PSG of sleep-disordered breathing, patients need to be observed for two nights in a specialized hospital; the first night is purely for diagnosis, and the second night is required for titration of treatment parameters by the clinician. Therefore, PSG is expensive and inconvenient. PSG is particularly unsuitable for home sleep testing.

[0086] A clinical expert may adequately diagnose or monitor a patient based on visual observation of the PSG signal. However, there are situations where a clinical expert is not available or cannot be paid. Different clinical experts may have different opinions about the patient's condition. Furthermore, a given clinical expert may apply different criteria at different times. Summary of the Invention [Problem to be solved by the invention]

[0087] 3. Brief description of the technology

[0088] The present technology relates to the provision of medical devices for use in the diagnosis, amelioration, treatment or prevention of respiratory disorders, which medical devices have one or more of improved comfort, cost, effectiveness, ease of use and manufacturability. [Means for solving the problem]

[0089] A first aspect of the present technology relates to a device for use in the diagnosis, amelioration, treatment or prevention of respiratory disease.

[0090] Another aspect of the present technology relates to methods for use in the diagnosis, amelioration, treatment or prevention of respiratory disorders.

[0091] One aspect of certain forms of the present technology is to provide methods and / or devices that improve patient compliance with respiratory treatment.

[0092] One aspect of the present technology relates to a patient interface that includes: a plenum chamber pressurizable to a therapeutic pressure of at least 6 cmH2O above ambient air pressure, the plenum chamber including a plenum chamber inlet port, the plenum chamber inlet port sized and configured to receive an airflow at the therapeutic pressure for breathing by the patient; a sealing structure constructed and arranged to be shaped to form a seal with an area of ​​the patient's face about an entrance to the patient's airways, whereby the airflow at the therapeutic pressure is delivered to at least an entrance to the patient's nasal passages, the seal being formed to prevent air from exiting the plenum chamber between the sealing structure and the area of ​​the patient's face, the sealing structure being configured to seal the plenum chamber throughout the patient's respiratory cycle in use. a sealing structure constructed and arranged to maintain a therapeutic pressure on the patient's head when the patient is lying in a lateral sleeping position and when the patient is lying in a supine sleeping position, the positioning and stabilizing structure for maintaining the sealing structure in a therapeutically effective position on the patient's head when the patient is lying in a lateral sleeping position and when the patient is lying in a supine sleeping position, the positioning and stabilizing structure including a low profile side portion and a low profile rear portion; an exhalation vent structure configured to allow continuous vent flow from within the plenum chamber to the surroundings when pressure within the plenum chamber is positive relative to the surroundings, the vent structure configured such that the vent flow rate is sufficient to assist in reducing rebreathing of exhaled CO2 by the patient on both patient inhalation and patient exhalation while maintaining a therapeutic pressure within the plenum chamber in use, wherein the sealing structure includes a sealing surface that forms a seal against the patient's face in use, and the sealing structure includes a tether extending between a first inner surface region of the sealing structure opposite the sealing surface and a second inner surface region of the patient interface to resist deformation of the sealing structure.

[0093] In embodiments, (a) the sealing structure may include a second inner surface region, the second inner surface region spaced apart from the first inner surface region; (b) the plenum chamber may include a second inner surface region, the second inner surface region spaced apart from the first inner surface region; (c) the tether and the sealing structure may include a unitary structure formed from a homogenous material; (d) the homogenous material may be silicone rubber; (e) the silicone rubber may be liquid silicone rubber or compression molded silicone rubber; (f) the sealing structure may include a sealing flap at an edge region, the sealing flap shaped and arranged to seal against at least a side of the patient's nose in use, the sealing flap being thinner than adjacent regions of the sealing structure; and (g) the first inner surface region may include a tether spaced apart inwardly from the sealing flap. (h) the tether may extend from the sealing structure proximate at the edge region such that the tether forms an extension of the sealing surface; (i) the tether may include an inner surface and the sealing structure may include an inner surface; (j) the inner surface of the tether is adjacent to and separated from the inner surface of the sealing structure; (k) the plenum chamber may be constructed from a transparent material; (l) the patient interface may be configured such that no part of the patient interface structure enters the oral cavity when in use; (m) the sealing structure may be configured such that it does not extend into the patient's airway when in use; (n) the sealing structure may be configured such that it does not extend under the chin rise region when in use; and / or (o) the plenum chamber may be configured such that it does not cover the eyes when in use.

[0094] Another aspect of the present technology relates to an assembly for a patient interface including: a plenum chamber pressurizable to a therapeutic pressure of at least 6 cmH2O above ambient air pressure, the plenum chamber including a plenum chamber inlet port sized and configured to receive an airflow at the therapeutic pressure to be breathed by the patient; a sealing structure constructed and arranged to be shaped to form a seal with an area of ​​the patient's face about an entrance to the patient's airways whereby the airflow at the therapeutic pressure is delivered to at least an entrance to the patient's nasal passages, the seal being shaped to prevent air from exiting the plenum chamber between the sealing structure and the area of ​​the patient's face, the sealing structure constructed and arranged to maintain the therapeutic pressure in the plenum chamber throughout the patient's respiratory cycle in use, the sealing structure including a sealing surface that forms a seal against the patient's face in use, the sealing structure including a connection extending between a first inner surface area of ​​the sealing structure opposite the sealing surface and a second inner surface area of ​​the assembly such that the connection is resistant to deformation of the sealing structure.

[0095] In examples, (a) the sealing structure may include a second inner surface region, the second inner surface region spaced apart from the first inner surface region, (b) the plenum chamber may include a second inner surface region, the second inner surface region spaced apart from the first inner surface region, (c) the connection and the sealing structure may include a unitary structure formed from a homogenous material, (d) the homogenous material may be silicone rubber, (e) the silicone rubber may be liquid silicone rubber or compression molded silicone rubber, (f) the sealing structure may include a sealing flap at an edge region, the sealing flap shaped and positioned to seal against at least a side of the patient's nose in use, the sealing flap being thinner than an adjacent region of the sealing structure, and (g) the first inner surface region may include a sealing flap extending from the sealing flap to an inner side of the patient's nose in use. (h) the connecting portion may extend proximally from the sealing structure at the edge region such that the connecting portion forms an extension of the sealing surface; (i) the connecting portion may include an inner surface and the sealing structure may include an inner surface, the inner surface of the connecting portion being adjacent to and separated from the inner surface of the sealing structure; (j) the plenum chamber may be constructed from a transparent material; (k) the assembly may be configured such that no part of the assembly enters the oral cavity in use; (l) the sealing structure may be configured such that it does not extend into the patient's airway in use; (m) the sealing structure may be configured such that it does not extend below the chin rise region in use; and / or (n) the plenum chamber is configured such that it does not cover the eyes in use.

[0096] One form of the present technology includes a sealing structure for sealing against a user's face around the user's airway, the sealing structure including a flap or membrane that extends inwardly into the user's airway and includes an attachment structure to prevent an inner boundary of the flap or membrane from being blown outward (e.g., double-folded backward) due to internal pressurization.

[0097] In embodiments, the attachment structure may include one or more ribs / tie / connectors / connecting structures, flaps extending from the membrane and folded inwardly and attached to another structure to form a tube or loop, or a tube positioned underneath and attached to the membrane.

[0098] Another aspect of one form of the present technology is a sealing structure for a patient interface for sealed delivery of airflow to an entrance to a patient's airways, including at least an entrance to the patient's nasal passages, at a continuous positive pressure relative to ambient air pressure. The patient interface is configured to maintain a therapeutic pressure in use in a range of about 3 cmH2O to about 40 cmH2O above ambient air pressure throughout the patient's breathing cycle while the patient is sleeping, thereby improving sleep disordered breathing. The sealing structure includes a sealing surface configured to form a seal around an entrance to the patient's airways, and a loop. The loop folds the sealing structure inwardly around an outer periphery of the sealing structure to form a substantially tubular structure such that the loop is continuous, the loop including a portion of the sealing surface.

[0099] In an embodiment, (a) the sealing structure further includes a sealing flap projecting to an inner periphery of the sealing structure, (b) the sealing flap is configured to form a seal against a side of the patient's nose above the nasal bone, (c) the sealing flap is configured to avoid sealing against the ala, (d) a portion of the sealing surface is more flexible relative to a remainder of the portion of the loop sealing surface and includes a thinner wall than a remainder of the loop, (e) the portion of the sealing surface includes a thicker wall than a remainder of the loop, (f) the loop is positioned to contact a side wall of the nose including the ala, (g) the loop provides a continuous surface configured to maintain contact with a side of the nose above the patient's nasal bone, (h) the loop includes at least one closed end, and (i) the loop is configured to fold the sealing structure inwardly to a connection point is formed on an inner surface of the sealing structure, (j) the connection point is positioned relative to the sealing surface to apply sufficient tension to the loop when therapeutic pressure is applied to the inner surface of the loop to neutralize outward rupture of the sealing surface, (k) the loop forms a predetermined angle at the connection point, the predetermined angle determining the tension in the loop upon application of therapeutic pressure, (l) the connection point is adjustable, (m) the connection point is a releasable connection, (n) the sealing structure further includes a second connection point, (o) the sealing surface includes a low friction area to reduce contact with the patient's face, (p) the low friction area is a matte surface, (q) the low friction area is adapted to allow the sides of the patient's nose to slide freely against the sealing surface, and / or (r) the loop provides a borderless sealing surface.

[0100] Another aspect of one form of the present technology is a patient interface for sealingly delivering an airflow at a continuous positive pressure relative to ambient air pressure to an entrance to a patient's airway, the entrance to the patient's airway including at least the patient's nasal entrance. The patient interface is configured to maintain a therapeutic pressure in use in a range of about 3 cmH2O to about 40 cmH2O above ambient air pressure throughout the patient's breathing cycle while the patient is sleeping, thereby improving sleep disordered breathing. The patient interface includes a sealing structure for sealing the patient interface against the patient's face. The sealing structure includes a sealing surface configured to form a seal around the entrance to the patient's airway, and a loop for folding the sealing structure inwardly about a periphery of the sealing structure such that the loop is continuous to form a substantially tubular structure, the loop including a portion of the sealing surface. The patient interface further includes a positioning and stabilizing structure for maintaining sealing contact between the sealing structure and an area surrounding the entrance to the patient's airway while maintaining a therapeutic pressure at the entrance to the patient's airway; a plenum chamber that is pressurized in use to a pressure above ambient pressure; and a gas exhaust vent configured to allow a flow of the patient's exhaled CO2 to flow outside the patient interface, thereby minimizing rebreathing of exhaled CO2 by the patient.

[0101] In an embodiment, (a) the sealing flap protrudes into an inner periphery of the sealing structure, (b) the sealing flap is configured to form a seal adjacent a side of the nose above the maxilla against a side of the nose above the nasal bone when the patient's canthus is pressed against the canthus of the eye, (c) the sealing flap is configured to avoid wing sealing, (d) a portion of the sealing surface is more flexible than the remainder of the loop, (e) a portion of the sealing surface includes a thinner wall than the remainder of the loop, (f) a portion of the sealing surface includes a thicker wall than the remainder of the loop, (g) the sealing surface includes an area of ​​low friction to reduce adhesion with the patient's face, (h) the low friction area is a matte surface, (i) the low friction area is adapted to allow the side of the patient's nose to slide freely against the sealing surface, (j) the first loop defines an area of ​​the sealing structure adapted to contact the patient's face, and (k) the second loop defines an area of ​​the sealing structure adapted to contact the patient's face. The first portion and the second portion are part of a region of the sealing structure adapted to contact the patient's face, (l) the first loop is continuous, (m) the second loop is positioned in contact with or alongside the patient's nose, (n) the second loop is positioned such that the substantially tubular structure is adapted to be positioned in contact with or alongside the patient's nose, (o) the substantially tubular structure is adapted to be positioned substantially parallel to the side of the patient's nose, (p) the sealing structure further comprises a second one of the second loops, (g) the substantially tubular structure comprises a hollow interior adapted to be in fluid communication with a pressure above ambient pressure, (r) the substantially tubular structure comprises two open ends, and / or (s) the second loop is adapted to prevent rupture of the second loop when the patient interface is internally pressurized or adjusted by the patient.

[0102] Another aspect of one form of the present technology is a patient interface for delivering airflow at a continuous positive pressure relative to ambient air pressure in a sealed manner to an entrance to a patient's airways including at least the entrance to the patient's nostrils. The patient interface is configured to maintain a therapeutic pressure in a range of about 3 cmH2O to about 40 cmH2O above ambient air pressure during the patient's entire breathing cycle while the patient is sleeping, in use, such that sleep disordered breathing is ameliorated. The patient interface includes a sealing structure for sealing the patient interface against the patient's face. The sealing structure includes a face contacting portion adapted to contact a periphery of the entrance to the patient's airways and a first substantially cylindrical region having at least a continuous circumference. A portion of the cylindrical region includes a portion of the face contacting portion. The patient interface further includes a positioning and stabilizing structure for maintaining sealing contact between the sealing structure and an area surrounding the entrance to the patient's airway while maintaining a therapeutic pressure at the entrance to the patient's airway; a plenum chamber that is pressurized in use to a pressure above ambient pressure; and a gas exhaust vent configured to allow a flow of the patient's exhaled CO2 to flow outside the patient interface, thereby minimizing rebreathing of exhaled CO2 by the patient.

[0103] In embodiments, (a) the sealing structure includes an unrestricted edge adjacent an end of the first substantially cylindrical region, (b) the sealing structure includes an unrestricted edge except for the first substantially cylindrical region all around an entrance to the patient's airway, (c) the face contact portion forms a convex surface adapted to contact the patient's face, (d) the first substantially cylindrical region is disposed in contact with or alongside the patient's wings, (e) the first substantially cylindrical region is disposed substantially parallel to the patient's wings, and (f) the patient interface is disposed between a second of the cylindrical regions. (g) the cylindrical region includes a second substantially cylindrical region having a second continuous circumference, a portion of the second cylindrical region includes a second portion of the face contacting portion; (h) the first substantially cylindrical region includes a hollow interior adapted to be in fluid communication with a pressure greater than ambient pressure; (i) the first substantially cylindrical region includes two open ends; and / or (j) the first substantially cylindrical region is adapted to prevent rupture of the face contacting portion when the patient interface is internally pressurized or adjusted by the patient.

[0104] Another aspect of one form of the present technology is a patient interface for sealingly delivering an airflow at a continuous positive pressure relative to ambient air pressure to an entrance to a patient's airways, including at least the entrance to the patient's nostrils, configured to maintain a therapeutic pressure in a range of about 3 cmH2O to about 40 cmH2O above ambient air pressure throughout the patient's breathing cycle while the patient is sleeping, such that sleep disordered breathing is ameliorated. The patient interface includes a sealing structure including a material double-folded to form a continuous tubular shape, the sealing structure configured to contact the patient's face with only a portion of the circumference of the tubular shape; a positioning and stabilizing structure that maintains sealing contact between the sealing structure and the nasal passages around the entrance to the patient's airways while maintaining a therapeutic pressure at the entrance to the patient's airways; a plenum chamber that is pressurized at a pressure above ambient pressure in use; and a gas outlet vent configured to allow the patient's exhaled CO2 to flow outside the patient interface, thereby minimizing rebreathing of the exhaled CO2 by the patient, the interior of the tubular shape adapted to be in fluid communication with a pressure above ambient pressure.

[0105] In an embodiment, (a) the continuous tubular shape has an inner tube surface and an outer tube surface, the inner tube surface adapted to be exposed to a pressure above ambient pressure in use, a first portion of the outer tube surface adapted to be exposed to ambient pressure in use, and a second portion of the outer tube surface adapted to be exposed to a pressure above ambient pressure in use, (b) the sealing structure further comprises a surface that contacts the periphery of the patient's airway, the portion of the continuous tubular shape being a portion of the surface, (c) the continuous tubular shape is open on at least one end, and (d) the continuous tubular shape is open on two ends. (e) the continuous tubular shape is adapted to line up with the patient's wings; (f) the continuous tubular shape is adapted to contact the patient's wings; (g) the material is folded to form a second continuous tubular shape, where only a portion of the circumference of the second continuous tubular shape is configured to contact the patient's face; (h) the continuous tubular shape is adapted to be on opposite sides of the patient's nose; and / or (i) the continuous tubular shape is adapted to prevent the material from bursting when the patient interface is internally pressurized or adjusted by the patient.

[0106] Another aspect of one form of the present technology is a patient interface for delivering airflow at a continuous positive pressure relative to ambient air pressure in a sealed manner to an entrance to a patient's airways including at least the patient's nostril entrances. The patient interface is configured to maintain a therapeutic pressure in a range of about 3 cmH2O to about 40 cmH2O above ambient air pressure during the patient's entire breathing cycle while the patient is sleeping, in use, such that sleep disordered breathing is ameliorated. The patient interface includes a sealing structure for sealing the patient interface against the patient's face. The sealing structure includes a first face contacting region with an unconnected edge at an inner boundary of the sealing structure and a second face contacting region that is part of a tubular structure, the first face contacting region and the second face contacting region each forming a continuous membrane configured to contact the patient's face around the entrance to the patient's airways. The patient interface further includes a positioning and stabilizing structure for maintaining sealing contact between the sealing structure and an area surrounding the entrance to the patient's airway while maintaining a therapeutic pressure at the entrance to the patient's airway; a plenum chamber that is pressurized in use to a pressure above ambient pressure; and a gas exhaust vent configured to allow a flow of the patient's exhaled CO2 to flow outside the patient interface, thereby minimizing rebreathing of exhaled CO2 by the patient.

[0107] In embodiments, (a) the patient interface further includes a plurality of second face contacting regions, (b) the second face contacting regions are adapted to contact the patient's face adjacent or on the patient's wings, and / or (c) the tubular structure is adapted to prevent rupture of the continuous membrane when the patient interface is internally pressurized or adjusted by the patient.

[0108] Another aspect of one form of the present technology is a patient interface for sealingly delivering airflow at a continuous positive pressure relative to ambient air pressure to an entrance to a patient's airways, including at least the patient's nostril entrances. The patient interface is configured to maintain a treatment pressure in a range of about 3 cmH2O to about 40 cmH2O above ambient air pressure during the patient's entire breathing cycle while the patient is sleeping, in use, to improve sleep disordered breathing. The patient interface includes a sealing structure for sealing the patient interface against the patient's face. The sealing structure includes a sealing membrane and a flap. The flap is attached to the sealing membrane on a first end and to another structure on a second end to prevent the sealing membrane from bursting outwardly due to the treatment pressure. The patient interface further includes a positioning and stabilizing structure for maintaining sealing contact between the sealing structure and an area surrounding the entrance to the patient's airway while maintaining a therapeutic pressure at the entrance to the patient's airway; a plenum chamber that is pressurized in use to a pressure above ambient pressure; and a gas exhaust vent configured to allow a flow of the patient's exhaled CO2 to flow outside the patient interface, thereby minimizing rebreathing of exhaled CO2 by the patient.

[0109] In embodiments, (a) the sealing membrane and the flap form part of a tubular structure, and / or (b) the sealing membrane is adapted to contact the entire circumference of the entrance to the patient's airway, and the flap is provided around only a portion of the circumference.

[0110] Another aspect of one form of the present technology is a patient interface for delivering a flow of air at a continuous positive pressure relative to ambient air pressure in a sealed manner to an entrance to a patient's airways, including at least the entrance to the patient's nostrils. The patient interface is configured to maintain a therapeutic pressure in a range of about 3 cmH2O to about 40 cmH2O above ambient air pressure throughout the patient's breathing cycle while the patient is sleeping, such that sleep disordered breathing is ameliorated. The patient interface includes a sealing structure for sealing the patient interface against the patient's face. The sealing structure includes a sealing membrane adapted to contact the patient's face around the entrance to the patient's airways, and a cylindrical area attached to the underside of the sealing membrane. The patient interface further includes a positioning and stabilizing structure for maintaining sealing contact between the sealing structure and the area around the entrance to the patient's airways while maintaining a therapeutic pressure at the entrance to the patient's airways; a plenum chamber that is pressurized at a pressure above ambient pressure in use; and a gas outlet vent configured to allow a flow of the patient's exhaled CO2 to flow out of the patient interface, thereby minimizing rebreathing of exhaled CO2 by the patient.

[0111] In embodiments, (a) the cylindrical region is positioned adjacent to the patient's wing; (b) the cylindrical region includes an axis that is substantially parallel to the patient's wing; (c) the cylindrical region is adapted to prevent the sealing membrane from being blown away from an entrance to the patient's airway when the plenum chamber is pressurized above ambient pressure; and / or (d) the sealing membrane includes an unconnected edge all around the entrance to the patient's airway.

[0112] Another aspect of one form of the present technology is a patient interface for delivering airflow at a continuous positive pressure relative to ambient air pressure in a sealed manner to an entrance to a patient's airways, including at least the entrance to the patient's nostrils. The patient interface is configured to maintain a therapeutic pressure in a range of about 3 cmH2O to about 40 cmH2O above ambient air pressure during the patient's entire breathing cycle while the patient is sleeping, in use, such that sleep disordered breathing is ameliorated. The patient interface includes a sealing structure for sealing the patient interface against the patient's face. The sealing structure includes a sealing membrane including inner and outer surfaces adapted to contact the patient's face around the entrance to the patient's airways, and ribs attached to an underside of the inner surface such that the ribs resist deformation of the sealing membrane when pressure is applied to the inner surface. The patient interface further includes a positioning and stabilizing structure for maintaining sealing contact between the sealing structure and an area surrounding the entrance to the patient's airway while maintaining a therapeutic pressure at the entrance to the patient's airway; a plenum chamber that is pressurized in use to a pressure above ambient pressure; and a gas exhaust vent configured to allow a flow of the patient's exhaled CO2 to flow outside the patient interface, thereby minimizing rebreathing of exhaled CO2 by the patient.

[0113] In embodiments, (a) the outer surface includes a convex portion, (b) the inner surface has a concave portion, (c) the concave portion and the convex portion are disposed directly opposite one another on the outer surface and the inner surface, respectively, and the ribs are attached to the inner surface at the concave portion, (d) the ribs are readily crushed by forces applied to the patient interface when the patient interface is held by a patient, (e) the patient interface further includes a plurality of ribs, (f) the ribs are adapted to fit adjacent the patient's nose, (g) the ribs are adapted to prevent rupture of the sealing membrane when the patient interface is internally pressurized or adjusted by the patient, and / or (h) the ribs are substantially perpendicular to the inner surface.

[0114] Another aspect of one form of the present technology relates to a cushion assembly for a patient interface for sealingly delivering airflow at a continuous positive pressure relative to ambient air pressure to an entrance to a patient's airways, including at least the entrance to the patient's nares. The patient interface is configured to maintain a therapeutic pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure during the patient's entire breathing cycle while the patient is sleeping, in use, to improve sleep disordered breathing. The cushion assembly includes an elastomeric support section. The cushion assembly also includes an elastomeric seal-forming structure. The elastomeric seal-forming structure is supported by the elastomeric support section and shaped to be bisected by a sagittal plane. The sagittal plane includes tangents to the elastomeric seal-forming structure at upper and lower contact points. The elastomeric support section is stiffer than the elastomeric seal-forming structure. Additionally, the elastomeric support section and the elastomeric seal-forming structure define a chamber. The elastomeric seal-forming structure may include an inner surface that forms a boundary of the chamber, and may include an outer surface opposite the inner surface. The elastomeric seal-forming structure may also include a first compliant region including an upper contact and a second compliant region separated from the first compliant region by a support region. The support region is stiffer than the first compliant region and the second compliant region. The stiffer support region may extend to or be anchored to the elastomeric support region. Additionally, at each point within the stiff support region, when the outer surface has a positive curvature, the inner surface has a negative curvature, and when the outer surface has a negative curvature, the inner surface has a positive curvature.

[0115] Another aspect of one form of the present technology relates to a cushion assembly for a patient interface for sealingly delivering airflow at a continuous positive pressure relative to ambient air pressure to an entrance to a patient's airways, including at least the patient's nares. The patient interface is configured to maintain a therapeutic pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure during the patient's entire breathing cycle while the patient is sleeping, in use, to improve sleep disordered breathing. The cushion assembly may include an elastomeric support section and an elastomeric seal-forming structure. The elastomeric seal-forming structure may be supported by the elastomeric support section and shaped to be bisected by a sagittal plane. The sagittal plane includes a tangent to the elastomeric seal-forming structure at an upper contact point and a lower contact point, and the elastomeric support section is stiffer than the elastomeric seal-forming structure. The elastomeric seal-forming structure may include a first compliant region including the upper contact point and a second compliant region separated from the first compliant region by a spring region. The spring region has a greater elastomeric wall thickness than the first compliant region and the second compliant region. The spring region may be tapered such that the elastomeric wall thickness increases as it approaches the support location. Additionally, the spring region may have a curve extending from the seal-forming structure to the support location.

[0116] Another aspect of one form of the present technology relates to a cushion assembly for a patient interface for sealingly delivering airflow at a continuous positive pressure relative to ambient air pressure to an entrance to a patient's airways, including at least the patient's nares. The patient interface is configured to maintain a therapeutic pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure throughout the patient's breathing cycle while the patient is sleeping, in use, to improve sleep disordered breathing. The cushion assembly may include an elastomeric seal-forming structure shaped to be bisected by a sagittal plane. The sagittal plane has tangents to the elastomeric seal-forming structure at upper and lower tangents. The saddle-shaped upper region of the elastomeric seal-forming structure may straddle the sagittal plane and may include an upper tangent. The elastomeric seal-forming structure may transition from the saddle-shaped region in the cylindrical upper region to a hemispherical upper region offset from the sagittal plane. An elastomeric wall thickness of the elastomeric seal-forming structure may be thicker in the cylindrical upper region than in the saddle-shaped upper region and the hemispherical upper region. Another aspect of one form of the present technology relates to a cushion assembly for a patient interface for delivering airflow at a continuous positive pressure relative to ambient air pressure in a sealed manner to an entrance to a patient's airways, including at least the patient's nostril entrances. The patient interface is configured to maintain a therapeutic pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure throughout the patient's breathing cycle while the patient is sleeping, such that sleep disordered breathing is ameliorated. The cushion assembly may include an elastomeric seal-forming structure with an inner surface defining at least a portion of a boundary of a chamber, the elastomeric seal-forming structure having a rear central opening and a front central opening opposite the rear central opening, the elastomeric seal-forming structure including a plurality of closed paths coaxial with the rear central opening. An elastomeric wall thickness of the elastomeric seal-forming structure may vary along one of the plurality of closed paths. An inner surface of a thicker portion of the elastomeric wall along one of the plurality of closed paths may be curved in a direction of an open path extending from the rear central opening to the front central opening. The plurality of closed paths includes an innermost path.Along the innermost path, the elastomeric wall thickness of the elastomeric seal-forming structure remains constant.

[0117] Another aspect of one form of the present technology relates to a cushion assembly for a patient interface for sealingly delivering airflow at a continuous positive pressure relative to ambient air pressure to an entrance to a patient's airways including at least the entrance to the patient's nares. The patient interface is configured to maintain a therapeutic pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure during the patient's entire breathing cycle while the patient is sleeping, in use, to improve sleep disordered breathing. The cushion assembly may include an elastomeric support section and an elastomeric seal-forming structure. The elastomeric seal-forming structure may be supported by the elastomeric support section, the elastomeric support section being stiffer than the elastomeric seal-forming structure. The elastomeric seal-forming structure may include a nasal bridge region configured to seal against the bridge of the patient's nose when the cushion is attached to the patient's face, and a compliant region configured to seal against the sides of the patient's nose when the cushion is attached to the patient's face. The elastomeric seal-forming structure may also include a support region that separates the nasal bridge surface from the compliant region, the support region being thicker than the nasal bridge region and the compliant region. The support region may be tapered such that the elastomeric wall thickness of the support region increases approaching the support site.

[0118] Another aspect of one form of the present technology relates to a cushion assembly for a patient interface for delivering airflow at a continuous positive pressure relative to ambient air pressure in a sealed manner to an entrance to a patient's airways including at least the entrance to the patient's nares. The patient interface is configured to maintain a therapeutic pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure during the patient's entire breathing cycle while the patient is sleeping, in use, to improve sleep disordered breathing. The cushion assembly may include an elastomeric seal-forming structure with an outer surface configured to seal against the patient's face when the cushion is installed on the patient's face, the elastomeric seal-forming structure having an inner surface opposing the outer surface and defining at least a portion of a chamber. There may be a central opening in the seal-forming structure configured to receive at least a portion of the patient's nose when the cushion is installed on the patient's face. The seal-forming structure may include a plurality of closed paths that are coaxial with the central opening. An elastomeric wall thickness of the elastomeric seal-forming structure may vary along one of the plurality of closed paths. A thicker portion of the elastomeric wall along one of the plurality of closed paths may have an inner surface opposing the chamber. The inner surface is curved in the direction of an open path extending from the rear central opening to the forward central opening. The plurality of closed paths may include an innermost path. Along the innermost path, the elastomeric wall thickness of the elastomeric seal-forming structure is consistent.

[0119] Another aspect of one form of the present technology relates to a cushion assembly for a patient interface for sealingly delivering a flow of gas at a continuous positive pressure relative to ambient air pressure to an entrance to a patient's airways, including at least the entrance to the patient's nares. The patient interface is configured to maintain a therapeutic pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure during the patient's entire breathing cycle while the patient is sleeping, in use, to improve sleep disordered breathing. The cushion includes an elastomeric support section and an elastomeric seal-forming structure that is more flexible than the elastomeric support section. The elastomeric seal-forming structure may include a tubular structure with a continuous circumference. The cushion may also include a plenum chamber defined by the elastomeric support section and the elastomeric seal-forming structure. The plenum chamber may be configured to receive a positive pressure gas. Additionally, the tubular structure and the chamber may be bounded by a common inner surface of the elastomeric seal-forming structure.

[0120] Another aspect of one form of the present technology relates to a cushion assembly for a patient interface for sealingly delivering a flow of gas at a continuous positive pressure relative to ambient air pressure to an entrance to a patient's airways, including at least the entrance to the patient's nares. The patient interface is configured to maintain a therapeutic pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure during the patient's entire breathing cycle while the patient is sleeping, in use, to improve sleep disordered breathing. The cushion assembly includes an elastomeric support section and an elastomeric seal-forming structure that is more flexible than the elastomeric support section. The elastomeric seal-forming structure is supported by the elastomeric support section. Additionally, the elastomeric seal-forming structure may include a connection extending from an inner surface of the elastomeric seal-forming structure to an inner surface of the elastomeric support section. The cushion may also include a plenum chamber configured to receive positive pressure air. The plenum chamber may be defined by the elastomeric support section and the elastomeric seal-forming section. The connection may be arranged to withstand deformation of the seal-forming structure to prevent the sealing surface of the seal-forming structure from being deformed outwardly by pressurized gas in the plenum chamber.

[0121] Another aspect of one form of the present technology relates to a cushion assembly for a patient interface for sealingly delivering a flow of gas at a continuous positive pressure relative to ambient air pressure to an entrance to a patient's airways, including at least the patient's nares. The patient interface is configured to maintain a therapeutic pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure during the patient's entire breathing cycle while the patient is sleeping, in use, to improve sleep disordered breathing. The cushion assembly includes an elastomeric support section and an elastomeric seal-forming structure that is more flexible than the elastomeric support section. The elastomeric seal-forming structure extends from a first end to a second end, the first end being secured to the elastomeric support section. The second end of the elastomeric seal-forming structure is a free end and is not attached to any structure except at the point where the elastomeric seal-forming structure is looped, and the second end is secured to the point where the elastomeric seal-forming structure is looped.

[0122] Another aspect of one form of the present technology relates to a cushion assembly for a patient interface for sealingly delivering a flow of gas at a continuous positive pressure relative to ambient air pressure to an entrance to a patient's airways, including at least the patient's nares. The patient interface is configured to maintain a therapeutic pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure during the patient's entire breathing cycle while the patient is sleeping, in use, to improve sleep disordered breathing. The cushion assembly includes an elastomeric support section and an elastomeric seal-forming structure that is more flexible than the elastomeric support section. The plenum chamber is configured to receive the positive pressure air. Additionally, the plenum chamber is defined by the elastomeric support section and the elastomeric seal-forming section. A first cross-sectional shape of the elastomeric seal-forming structure is a closed loop, and a second cross-sectional shape of the elastomeric seal-forming structure is open.

[0123] Another aspect of one form of the present technology is a patient interface that is molded or otherwise constructed with a peripheral shape that is complimentary to the shape of the intended wearer.

[0124] One aspect of the present disclosure is a method for manufacturing a device.

[0125] One aspect of certain forms of the present technology is a medical device that is easy to use, for example, by individuals without medical training, individuals with limited dexterity or insight, or individuals with limited experience in using medical devices of this type.

[0126] One aspect of one form of the present technology is a portable RPT device that a person can carry with them (eg, around the home).

[0127] One aspect of one form of the present technology is a patient interface that can be cleaned at the patient's home, for example with soapy water, without the need for special cleaning equipment.One aspect of one form of the present technology is a patient interface that can be cleaned at the patient's home, for example with soapy water, without the need for special cleaning equipment.

[0128] The methods, systems, devices and apparatus described herein may enable improved functionality in a processor (e.g., a processor of a special purpose computer, a respiratory monitor and / or a respiratory treatment device). Additionally, the described methods, systems, devices and apparatus enable advances in the art of automated management, monitoring and / or treatment of respiratory conditions (e.g., sleep disorder breathing).

[0129] Of course, some of the above aspects may form sub-aspects of the present technology, and various one of the sub-aspects and / or aspects may be combined in various ways to form further aspects or sub-aspects of the present technology.

[0130] Other features of the present technology will become apparent in light of the information contained in the following detailed description, abstract, drawings, and claims. [Brief description of the drawings]

[0131] 4. Brief Description of the Drawings

[0132] The present technology is illustrated by way of one non-limiting example in the accompanying drawings, in which like reference symbols include like elements:

[0133] 4.1 Treatment system

[0134] [Figure 1A] 1A shows a system including a patient 1000 wearing a patient interface 3000. The system takes the form of nasal pillows and receives air at positive pressure supplied by an RPT device 4000. The air from the RPT device 4000 is humidified by a humidifier 5000 and travels along an air circuit 4170 to the patient 1000. A bed companion 1100 is also shown. The patient is sleeping in a supine sleep position. [Figure 1B] 1B shows a system including a patient 1000 wearing a patient interface 3000. The system takes the form of a nasal mask and receives air at positive pressure supplied by an RPT device 4000. Air from the RPT device is humidified by a humidifier 5000 and travels along an air circuit 4170 to the patient 1000. [Figure 1C] 1C includes a system including a patient 1000 wearing a patient interface 3000. The patient interface 3000 takes the form of a full face mask and receives a supply of air at positive pressure from an RPT device 4000. Air from the RPT device is humidified by a humidifier 5000 and travels along an air circuit 4170 to the patient 1000. The patient is sleeping in a lateral sleep position.

[0135] 4.2 Respiratory System and Facial Anatomy [Figure 2A] FIG. 2A shows an overview of the human respiratory system, including the nose and oral cavity, larynx, vocal folds, esophagus, trachea, bronchi, lungs, alveolar sacs, heart and diaphragm. [Figure 2B]FIG. 2B is a diagram of the human upper airway including the nasal cavity, nasal bones, lateral nasal cartilages, greater alar cartilage, nostrils, upper lip, lower lip, larynx, hard palate, soft palate, oropharynx, tongue, epiglottis, vocal cords, esophagus, and trachea. [Figure 2C] Figure 2C is a front view of the face including several features of the surface anatomy including the upper lip, upper vermilion lip, lower vermilion lip, lower lip, mouth width, inner corners of the eyes, alae of the nose, nasolabial folds and corners of the mouth. The directions of superior, inferior, radially inward and radially outward are also described. [Figure 2D] Figure 2D is a side view of the head including several features of the surface anatomy including the glabella, cerion, nasal tip, subnasal point, upper lip, lower lip, chin, nasal ridge, narrow apex, superior and inferior auricles. The directions of superior and inferior, and anterior and posterior are also described. [Figure 2E] Figure 2E is a further lateral view of the head. The approximate locations of the Frankfort horizontal and nasolabial angle are noted. The frontal plane is also noted. [Figure 2F] FIG. 2F is a bottom view of the nose including several features including the nasolabial fold, lower lip, upper vermilion, nostrils, subnasal point, columella, nasal tip, major axis of the nostril and sagittal plane. [Figure 2G] FIG. 2G is a side view of the superficial features of the nose. [Figure 2H] FIG. 2H shows the subcutaneous structures of the nose including the lateral cartilages, septal cartilage, greater alar cartilage, lesser alar cartilage, sesamoid cartilage, nasal bones, epidermis, adipose tissue, frontal process of the maxilla, and fibro-adipose tissue. [Figure 2I] FIG. 2I shows the mid-nasal incision, approximately a few millimeters from the sagittal plane, specifically showing the septal cartilage and the medial crus of the greater alar cartilage. [Figure 2J] FIG. 2J is a bony frontal view of the skull including the frontal, nasal and cheekbones. The nasal turbinates are shown along with the maxilla and mandible. [Figure 2K] FIG. 2K is a side view of the skull along with the outline of the head surface and some of the muscles. The following bones are shown: frontal, sphenoid, nasal, zygomatic, maxilla, mandible, parietal, temporal, and occipital. The mental protuberance is shown. The following muscles are shown: digastric, masseter, sternocleidomastoid, and trapezius. [Figure 2L] FIG. 2L shows the anterolateral aspect of the nose.

[0136] 4.3 Patient Interface [Figure 3A] FIG. 3A shows a patient interface in the form of a nasal mask in accordance with one form of the present technology. [Figure 3B] 3B is a schematic cross-sectional view of the structure cut at a point, where the outward normal is shown, and the curvature at this point has a positive sign and a relatively large magnitude compared to the magnitude of curvature shown in 3C. [Figure 3C] Figure 3C is a schematic cross-sectional view of the structure cut at a point, where the outward normal is shown, and the curvature at this point has a positive sign and a relatively small magnitude compared to the magnitude of curvature shown in Figure 3B. [Figure 3D] 3D is a schematic cross-sectional view of the structure cut at a point, where the outward normal is shown, and where the curvature value is zero. [Figure 3E] Figure 3E is a schematic cross-sectional view of the structure cut at a point, where the outward normal is shown, and the curvature at this point has a negative sign and a relatively small magnitude compared to the magnitude of curvature shown in Figure 3F. [Figure 3F] Figure 3F is a schematic cross-sectional view of the structure cut at a point, where the outward normal is shown, and the curvature at this point has a negative sign and a relatively large magnitude compared to the magnitude of curvature shown in Figure 3E. [Figure 3G] 3G shows a mask cushion including two pillows. The outer surface of the cushion is shown. The edge of the surface is shown. The dome region and the saddle region are shown. [Figure 3H] 3H shows a cushion for a mask. The outer surface of the cushion is illustrated. The edge of the surface is illustrated. The path on the surface between points A and B is illustrated. The straight line distance between A and B is illustrated. Two saddle regions and a dome region are illustrated. [Figure 3I]Figure 3I shows the surface of a structure with a one-dimensional hole drilled into it. The planar curves shown form the boundary of the one-dimensional hole. [Figure 3J] Figure 3J is a cross-sectional view through the structure of Figure 31. The surfaces shown bound a two-dimensional hole in the structure of Figure 3I. [Figure 3K] Figure 3K is a perspective view of the structure of Figure 3I including a two-dimensional hole and a one-dimensional hole, and the surfaces bounding the two-dimensional hole in the structure of Figure 3I are illustrated. [Figure 3L] FIG. 3L shows a mask with an inflatable bladder as a cushion. [Figure 3M] Figure 3M is a cross-sectional view of the mask of Figure 3L showing the inner surface of the bladder, which bounds the two-dimensional hole in the mask. [Figure 3N] Figure 3N shows a further cross section through the mask of Figure 3L. The inner surface is also shown. [Figure 3O] Figure 3O illustrates the left-hand rule. [Figure 3P] Figure 3P illustrates the right-hand rule. [Figure 3Q] FIG. 3Q shows a left ear including the left ear helix. [Figure 3R] FIG. 3R shows the right ear including the right ear helix. [Figure 3S] FIG. 3S shows a right-handed spiral. [Figure 3T] FIG. 3T is an illustration of a mask including the signature of the twist of the space curve defined by the edges of the sealing membrane in different regions of the mask.

[0137] 4.4 RPT Devices [Figure 3U] FIG. 3U shows an RPT device in accordance with one form of the present technology.

[0138] 4.5 Humidifier [Figure 3V] FIG. 3V is an isometric view of a humidifier in accordance with one form of the present technology. [Figure 3W]FIG. 3W is an isometric view of a humidifier in accordance with one form of the present technology, showing the humidifier reservoir 5110 removed from the humidifier reservoir dock 5130.

[0139] 4.6 Seal-forming structure and patient interface [Figure 4] FIG. 4 is a perspective view of the seal-forming structure. [Diagram 5] FIG. 5 is a perspective view of the seal-forming structure. [Figure 5A] FIG. 5A is a perspective view of a seal-forming structure in which a loop includes a closed end. [Figure 6] FIG. 6 is a plan view of the seal-forming structure. [Figure 7] FIG. 7 is a cross-sectional view taken along line 7-7 of FIG. [Figure 7A] FIG. 7A shows the same cross section as FIG. 7, but with a different angle of structure. [Figure 7B] FIG. 7B shows the mechanical attachment in a cross-sectional view of FIG. [Figure 7C] FIG. 7C shows the mechanical attachment in the cross-sectional view of FIG. [Figure 7D] FIG. 7D shows the mechanical attachment in the cross-sectional view of FIG. [Figure 7E] FIG. 7E shows the mechanical attachment in cross section of FIG. [Figure 7F] FIG. 7F shows the mechanical attachment in the cross-sectional view of FIG. [Figure 7G] FIG. 7G shows the mechanical attachment in the cross-sectional view of FIG. [Figure 7H] FIG. 7H shows the mechanical attachment in the cross-sectional view of FIG. [Figure 7I] FIG. 7I shows the mechanical attachment in the cross-sectional view of FIG. [Figure 8A] FIG. 8A is a cross-sectional view taken along the corresponding line in FIG. [Figure 8B] FIG. 8B is a cross-sectional view taken along the corresponding line in FIG. [Figure 8C] FIG. 8C is a cross-sectional view taken along the corresponding line in FIG. [Figure 8D] FIG. 8D is a cross-sectional view taken along the corresponding line in FIG. [Figure 8E] FIG. 8E is a cross-sectional view taken along the corresponding line in FIG. [Figure 8F] FIG. 8F is a cross-sectional view taken along the corresponding line in FIG. [Figure 8G] FIG. 8G is a cross-sectional view taken along the corresponding line in FIG. [Figure 9] FIG. 9 is a plan view of the seal-forming structure. [Figure 10] FIG. 10 is a perspective view of the seal-forming structure. [Figure 11] FIG. 11 is a simplified diagram of a tubular structure and a flap. [Figure 12] FIG. 12 is a simplified diagram of a tubular structure and a flap attached to a seal-forming structure. [Figure 13] FIG. 13 is a simplified diagram of the compliance of a seal-forming structure. [Figure 14] FIG. 14 is a perspective view of the seal-forming structure. [Figure 15] FIG. 15 is a cross-sectional view showing a rib of the seal-forming structure. [Figure 16] FIG. 16 is a cross-sectional view of a rib under compression. [Figure 17] FIG. 17 is a cross-sectional view of a rib under tension. [Figure 18] FIG. 18 is a cross-sectional view of a seal-forming structure. [Figure 19] FIG. 19 is a cross-sectional view of a seal-forming structure. [Figure 20] FIG. 20 shows various regions of the seal-forming structure. [Figure 21] FIG. 21 shows the seal-forming structure attached to the mask shell. [Figure 22] FIG. 22 is an exploded view of the seal-forming structure and two clips. [Diagram 23] FIG. 23 shows the cushion and clip. [Figure 23A]FIG. 23A is a cross-sectional view of FIG. 23 taken along line 23A-23A. [Figure 24A] FIG. 24A is a perspective view of a cushion assembly. [Figure 24B] FIG. 24B is a second perspective view of the cushion assembly of FIG. 24A. [Figure 25A] FIG. 25A is a front view of the cushion assembly of FIGS. 24A and 24B. [Figure 25B] FIG. 25B shows various cross sections taken along corresponding lines in FIG. 25A. [Figure 25C] FIG. 25C shows various cross sections taken along corresponding lines in FIG. 25A. [Figure 25D] FIG. 25D shows various cross sections taken along corresponding lines in FIG. 25A. [Figure 25E] FIG. 25E shows various cross sections taken along corresponding lines in FIG. 25A. [Figure 25F] FIG. 25F shows various cross sections taken along corresponding lines in FIG. 25A. [Figure 25G] FIG. 25G shows various cross sections taken along corresponding lines in FIG. 25A. [Figure 26] FIG. 26 is a rear view of the cushion assembly of FIGS. 24A and 24B. [Figure 27A] FIG. 27A illustrates various regions of the cushion assembly of FIGS. 24A and 24B. [Figure 27B] FIG. 27B illustrates various regions of the cushion assembly of FIGS. 24A and 24B. [Figure 27C] FIG. 27C illustrates a sagittal plane associated with the cushion assembly of FIGS. 24A and 24B. [Figure 27D] FIG. 27D illustrates a sagittal plane associated with the cushion assembly of FIGS. 24A and 24B. [Figure 27E] FIG. 27E shows coaxial closed and open paths on the cushion assembly of FIGS. 24A and 24B. [Figure 27F]FIG. 27F is a side view of the cushion assembly of FIGS. 24A and 24B. [Figure 27G] FIG. 27G shows various cross sections taken along corresponding lines in FIG. 27A. [Fig. 27H] FIG. 27H shows various cross sections taken along corresponding lines in FIG. 27A. [Figure 27I] FIG. 27I shows various cross sections taken along corresponding lines in FIG. 27A. [Figure 27J] FIG. 27J shows various cross sections taken along corresponding lines in FIG. 27A. [Figure 27K] FIG. 27K shows various cross sections taken along corresponding lines in FIG. 27A. [Figure 27L] FIG. 27L is a rear view of the cushion assembly of FIGS. 24A and 24B. [Figure 27M] FIG. 27M shows various cross sections taken along corresponding lines in FIG. 27L. [Figure 27N] FIG. 27N shows various cross sections taken along corresponding lines in FIG. 27L. [Figure 27O] FIG. 27O shows various cross sections taken along corresponding lines in FIG. 27L. [Figure 27P] FIG. 27P shows various cross sections taken along corresponding lines in FIG. 27L. [Figure 27Q] FIG. 27Q shows various cross sections taken along corresponding lines in FIG. 27L. [Figure 27R] FIG. 27R shows various cross sections taken along corresponding lines in FIG. 27L. [Figure 28A] FIG. 28A is a top perspective view of a seal-forming structure of a full-face patient interface according to an embodiment of the present technology. [Figure 28B] FIG. 28B is a front view of a seal-forming structure of a full-face patient interface according to an embodiment of the present technology. [Figure 28C] FIG. 28C is a rear view of a seal-forming structure of a full-face patient interface according to an embodiment of the present technology. [Figure 28D]FIG. 28D is a top view of a seal-forming structure of a full-face patient interface according to an embodiment of the present technology. [Figure 28E] FIG. 28E is a bottom view of a seal-forming structure of a full-face patient interface according to an embodiment of the present technology. [Figure 28F] FIG. 28F is a side view of a seal-forming structure of a full-face patient interface according to an embodiment of the present technology. [Figure 28G] FIG. 28G is a bottom perspective view of a seal-forming structure of a full-face patient interface according to an embodiment of the present technology. [Fig. 28H] FIG. 28H is another top perspective view of a seal-forming structure of a full-face patient interface according to an embodiment of the present technology. [Figure 28I] FIG. 28I is another bottom view of a seal-forming structure of a full-face patient interface according to an embodiment of the present technology. [Figure 28J] FIG. 28J is a cross-sectional view of a seal-forming structure of a full-face patient interface taken at line 28J-28J of FIG. 28B according to an embodiment of the present technology. [Figure 28K] FIG. 28K is a cross-sectional view of a seal-forming structure of a full-face patient interface taken at line 28K-28K of FIG. 28B according to an embodiment of the present technology. [Figure 28L] FIG. 28L is a cross-sectional view of a seal-forming structure of a full-face patient interface taken at line 28L-28L of FIG. 28B according to an embodiment of the present technology. [Figure 28M] FIG. 28M is a perspective view of the seal-forming structure of the full-face patient interface shown in FIG. 28L. [Figure 29A] FIG. 29A is a top perspective view of a seal-forming structure and plenum chamber assembly of a full-face patient interface according to an embodiment of the present technology. [Figure 29B] FIG. 29B is a front perspective view of a seal-forming structure and plenum chamber assembly of a full-face patient interface according to an embodiment of the present technology. [Figure 29C] FIG. 29C is a cross-sectional view of a seal-forming structure and plenum chamber assembly of a full-face patient interface taken at line 29C-29C of FIG. 29B according to an embodiment of the present technology. [Figure 29D] FIG. 29D is a cross-sectional view of a seal-forming structure and plenum chamber assembly of a full-face patient interface taken at line 29D-29D of FIG. 29B according to an embodiment of the present technology. [Figure 29E] FIG. 29E is a cross-sectional view of a seal-forming structure and plenum chamber assembly of a full-face patient interface taken at line 29E-29E of FIG. 29B according to an embodiment of the present technology. [Figure 30A] FIG. 30A is a top perspective view of a full-face patient interface according to an embodiment of the present technology. [Figure 30B] FIG. 30B is a top perspective view of a full-face patient interface according to an embodiment of the present technology. [Figure 31A] FIG. 31A is a top perspective view of a seal-forming structure of a nasal patient interface according to an embodiment of the present technology. [Figure 31B] FIG. 31B is a front view of a seal-forming structure of a nasal patient interface according to an embodiment of the present technology. [Figure 31C] FIG. 31C is a rear view of a seal-forming structure of a nasal patient interface according to an embodiment of the present technology. [Figure 31D] FIG. 31D is a top view of a seal-forming structure of a nasal patient interface according to an embodiment of the present technology. [Figure 31E] FIG. 31E is a bottom view of a seal-forming structure of a nasal patient interface according to an embodiment of the present technology. [Fig. 31F] FIG. 31F is a side view of a seal-forming structure of a nasal patient interface according to an embodiment of the present technology. [Figure 31G] FIG. 31G is a bottom perspective view of a seal-forming structure of a nasal patient interface according to an embodiment of the present technology. [Fig. 31H]FIG. 31H is another top perspective view of a seal-forming structure of a nasal patient interface according to an embodiment of the present technology. [Fig. 31I] FIG. 31I is another bottom view of a seal-forming structure of a nasal patient interface according to an embodiment of the present technology. [Figure 31J] FIG. 31J is a cross-sectional view of a seal-forming structure of a nasal patient interface taken at line 31J-31J of FIG. 31B according to an embodiment of the present technology. [Figure 31K] FIG. 31K is a cross-sectional view of a seal-forming structure of a nasal patient interface taken at line 31K-31K of FIG. 31B according to an embodiment of the present technology. [Figure 31L] FIG. 31L is a cross-sectional view of a seal-forming structure of a nasal patient interface taken at line 31L-31L of FIG. 31B according to an embodiment of the present technology. [Figure 31M] FIG. 31M is a perspective view of the seal-forming structure of the full-face patient interface shown in FIG. 31L. [Figure 32A] FIG. 32A is a top perspective view of an assembly of a seal-forming structure and plenum chamber of a nasal patient interface according to an embodiment of the present technology. [Figure 32B] FIG. 32B is a front perspective view of a seal-forming structure and plenum chamber assembly of a nasal patient interface according to an embodiment of the present technology. [Figure 32C] FIG. 32C is a cross-sectional view of a seal-forming structure and plenum chamber assembly of a nasal patient interface taken at line 32C-32C of FIG. 32B according to an embodiment of the present technology. [Fig. 32D] FIG. 32D is a cross-sectional view of a seal-forming structure and plenum chamber assembly of a nasal patient interface taken at line 32D-32D of FIG. 32B according to an embodiment of the present technology. [Figure 32E] FIG. 32E is a cross-sectional view of a seal-forming structure and plenum chamber assembly of a nasal patient interface taken at line 32E-32E of FIG. 32B according to an embodiment of the present technology. [Fig. 32F]FIG. 32F is a perspective view of the seal-forming structure and plenum chamber assembly of the nasal patient interface shown in FIG. 32E. [Figure 33A] FIG. 33A is a perspective view of a patient interface assembly having an air delivery tube. [Figure 33B] FIG. 33B is another perspective view of the patient interface assembly of FIG. 33A having an air delivery tube. [Figure 33C] FIG. 33C is a perspective view of the patient interface assembly of FIGS. 33A and 33B with headgear. [Figure 34A] FIG. 34A is a top perspective view of a nasal patient interface according to an embodiment of the present technology. [Figure 34B] FIG. 34B is a top perspective view of a nasal patient interface according to an embodiment of the present technology. [Diagram 35] FIG. 35 shows various regions of a seal-forming structure according to another embodiment of the present technology. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0140] 5 Detailed Description of the Embodiments of the Present Technology

[0141] Before describing the present technology in further detail, it should be understood that the present technology is not limited to the specific embodiments described herein, which may vary. It should also be understood that the terminology used in the present disclosure is for the purpose of describing the specific embodiments described herein, and is not intended to be limiting.

[0142] The following description is provided in conjunction with various embodiments that may share one or more common characteristics and / or features. It should be understood that one or more features of any one embodiment may be combined with one or more features of another embodiment or other embodiments. In addition, any single feature or combination of features in any of these embodiments may constitute an additional embodiment.

[0143] 5.1 Treatment

[0144] In one form, the present technology includes a method of treating a respiratory disorder, the method including the step of applying positive pressure to an entrance to the airways of a patient 1000.

[0145] In a particular embodiment of the present technology, a supply of air at positive pressure is provided to the patient's nasal passages via one or both nostrils.

[0146] In certain embodiments of the present technology, mouth breathing is restricted, limited or prevented.

[0147] 5.2 Treatment system

[0148] In one form, the present technology includes an apparatus or device for the treatment of respiratory disorders. The apparatus or device may include an RPT device 4000 that supplies pressurized air to a patient 1000 via an air circuit 4170 to a patient interface 3000.

[0149] 5.3 Patient Interface

[0150] A non-invasive patient interface 3000 according to one aspect of the present technology includes the following functionalities: a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilizing structure 3300, a vent 3400, a form of connection port 3600 for connection to an air circuit 4170, and a forehead support 3700. In some forms, the functionalities may be provided by one or more physical components. In some forms, one physical component may provide one or more functionalities. In use, the seal-forming structure 3100 is positioned to surround an entrance to the patient's airway to facilitate the supply of air at positive pressure to the airway.

[0151] The inventors have discovered that if the patient interface 3000 cannot comfortably deliver a minimum level of positive pressure to the airway, therapy may be ineffective.

[0152] A patient interface 3000 in accordance with one form of the present technology is constructed and arranged to provide an air supply at a positive pressure of at least 6 cmH20 relative to ambient.

[0153] A patient interface 3000 in accordance with one form of the present technology is constructed and arranged to provide an air supply at a positive pressure of at least 10 cmH20 relative to the surroundings.

[0154] A patient interface 3000 in accordance with one form of the present technology is constructed and arranged to provide an air supply at a positive pressure of at least 20 cmH20 relative to the surroundings.

[0155] 5.3.1 Seal formation structure

[0156] In one form of the present technology, the seal-forming structure 3100 provides a seal-forming surface and may further provide a cushioning function.

[0157] A seal-forming structure 3100 in accordance with the present technology may be constructed from a material that is soft, flexible and resilient (eg, silicone).

[0158] In one form, the non-invasive patient interface 3000 includes a seal-forming portion that, in use, forms a seal over the upper lip area (ie, upper lip) of the patient's face.

[0159] In one form, the non-invasive patient interface 3000 includes a seal-forming portion that, in use, forms a seal over the chin area of ​​the patient's face.

[0160] In certain forms of the present technology, a system is provided that includes more than one seal-forming structure 3100. Each seal-forming structure 3100 is configured to accommodate a different size and / or shape range. For example, the system may include one form of seal-forming structure 3100 suitable for large head sizes but not small head sizes, and another suitable for small head sizes but not large head sizes.

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

[0162] 4 is a perspective view of the seal-forming structure 3100 separated from the remainder of the patient interface 3000. The seal-forming structure includes a sealing surface 3105 configured to form a seal around the patient's airway. The seal may be formed around the patient's nose or the patient's nose and oral cavity.

[0163] The seal-forming structure 3100 includes a tether, connector, or loop 3110 that folds the sealing structure 3100 inward (e.g., toward the patient's face in use) about the periphery 3115 of the sealing structure 3100. The periphery 3115 may be generally defined as a wall that supports and / or is formed continuously with the sealing surface 3105. In this manner, the tether 3110 may form a substantially tubular structure 3120 such that the tether 3110 forms a continuous structure (e.g., a continuous circumference) with the sealing surface 3105 and the periphery 3115. Thus, the tether 3110 may include a portion of the sealing surface 3105, a portion of the periphery 3115, and portions that are neither the sealing surface 3105 nor the periphery 3115. The portion that is not the sealing surface 3105 or the periphery 3115 may take the form of a flap or sheet, attached or continuous with the sealing surface at one end and attached or continuous with the periphery 3115 at another end. The tether 3110 may be positioned in line with the patient's nose (e.g., along the alar), above the nasal bone or anywhere in between. Two tethers 3110 may be provided on opposite sides of the patient's nose. The tethers 3110 may be internally open, including at one or both ends, such that the tethers 3110 are internally pressurized (e.g., in fluid communication) with the patient's treatment pressure in use.

[0164] In one form of the present technology, the tether 3110 may extend only partially around the periphery of the seal-forming structure 3100.

[0165] In one form, the tether 3110 and the seal-forming structure 3100 do not form a closed pressurizable structure (e.g., a bladder), such that the space between the tether 3110 and the seal-forming structure 3100 is open to pressure inside the patient interface 3000.

[0166] In one form, the seal-forming structure 3100 has an edge and the tether 3110 holds the edge to prevent rupture at the edge.

[0167] The area of ​​the sealing surface 3105 other than the tether 3110 may include a sealing flap 3125 that projects inwardly toward the inner periphery 3100 of the sealing structure. The sealing flap 3125 may have an unconnected edge at or near a radially inner portion of the sealing surface 3105. The sealing flap 3125 may include a portion 3125a configured to form a seal against the side of the nose above the patient's nasal bone. The sealing flap 3125 may be structured to avoid sealing against the wing (e.g., by being spaced radially outwardly far enough away from the wing) so that contact with the wing is avoided or minimized.

[0168] Figure 5 is a perspective view of the seal-forming structure 3100 substantially opposite to Figure 4. The substantially tubular structure 3120 may be more readily apparent from this view. Figure 5A shows a tether 3110 with a closed end 3111. This view also shows the seal-forming structure 3100 without an underlying cushion, such that the seal-forming structure 3100 may be referred to as a single layer cushion.

[0169] FIG. 6 is a plan view of the seal-forming structure 3100 and serves as the basis for two cross-sectional views shown in FIGS.

[0170] FIG. 7 is a cross-sectional view taken through the tether 3110. The substantially tubular structure 3120 can be more easily distinguished from this view. The tether 3110 includes a relatively thicker section 3130 and a relatively thinner section 3135. The relatively thicker section 3130 can be 1 mm to 2 mm thick, or 1.3 mm to 1.7 mm thick, or about 1.5 mm thick. The relatively thinner section 3135 can be 0.2 mm to 0.8 mm thick, or 0.4 mm to 0.6 mm thick, or about 0.5 mm thick. Alternatively, the thickness of the relatively thicker section 3130 can be about 2.5 to 5 times the thickness of the relatively thinner section 3135, or about 2.8 to 3.3 times the thickness of the relatively thinner section 3135, or about 3 times the thickness of the relatively thinner section 3135. The relatively thicker sections 3130 are shown to comprise the perimeter 3115 and most of the sealing surface 3105 in the tether 3110. The relatively thinner sections 3135 fold the sealing structure inward and reconnect it to the seal-forming structure 3100 at or near the hinge structure 3140 at a connection point 3165. The hinge structure 3140 is shown as a localized relatively thin strip or line. This allows the seal-forming structure 3100 to bend or flex preferentially in place, allowing it to flex to conform to the patient's face. The relatively thicker sections 3130 provide sufficient elasticity to provide an effective seal against the patient's face. The relatively thinner sections 3135 may provide resistance to the sealing surface 3105 not bursting under pressure while preventing the sealing surface 3105 from becoming too stiff when forming an effective seal. Alternatively, the thicknesses of the relatively thicker section 3130 and the relatively thinner section 3135 may be reversed from that shown in Figure 7. Alternatively, the relatively thin section 3135 may extend to encompass the sealing surface 3105. Any combination of thicknesses may be used to achieve the desired combination of sealing ability and burst resistance.

[0171] The connection point 3165 may be determined based on the desired force applied from the tether 3110 or the desired resilience of the tether 3110. For example, as shown in FIG. 7A, the angle 3170 formed by the relatively thin section 3135 may be varied. As the angle 3170 varies, the tension in the relatively thin section 3135 also varies. Thus, the angle 3170 may be optimized for burst prevention and / or patient comfort.

[0172] The angle 3170 may be pre-determined in a number of ways. For example, if the seal-forming structure 3100 is a single molded piece, the angle 3170 is determined by the die used to form the seal-forming structure 3100. Different angles can be achieved by different dies. Alternatively, the relatively thin section 3135 may be manufactured unconnected, which allows the connection point 3165 to be formed in a subsequent assembly step. The connection point 3165 may be a mechanical connection or an adhesive. If an adhesive is used, the connection point 3165 may vary continuously within the acceptable attachment. Alternatively, a mechanical attachment may be used. Figures 7B-7I show an exemplary mechanical attachment. In Figures 7B-7E, the connection point 3165 is keyed so that different angles can be achieved at a single connection point 3165. Figures 7B and 7C show a first connection orientation of the keyed connection, and Figures 7D and 7E show a second connection orientation of the keyed connection. In Figures 7F-7I, multiple separate connection points 3165 are illustrated. The selected connection point 3165 determines the angle 3170. Figures 7F and 7G show a first separate connection of the separate connection points, and Figures 7H and 7I show a second separate connection of the separate connection points. The particular geometries shown in Figures 7B-7I are merely exemplary and should not be considered limiting. Other keyed or separate connection geometries may also be used.

[0173] 7, the tether 3110 can be positioned to contact the side walls of the nose, including the alar. The tether 3110 can also provide a continuous surface to maintain contact with the sides of the nose above the patient's nasal bone.

[0174] FIG. 8A shows a cross-sectional view taken through a vertical plane in FIG. 6. As best seen in FIG. 8, the tether 3110 is attached to the wall forming the perimeter 3115 at an attachment site 3145. As shown, the attachment site 3145 is a continuous section of the tether 3110 and can be achieved by molding the seal-forming structure 3100 in one piece. However, the attachment site 3145 can also be achieved in any other convenient manner (e.g., by fastening the free ends of the tether 3110 using some form of mechanical or chemical fastening such as adhesive). The attachment site 3145 can be selected along with the overall length of the tether 3110 such that sufficient tension is provided to the tether 3110 to counteract rupture of the sealing surface 3105 when pressure (e.g., therapeutic pressure) acts on the inner surface of the tether 3110 and pulls the seal-forming structure 3100 away from the patient's face and / or when sufficient headgear tension is present.

[0175] Part or all of the sealing surface 3105 may be an area of ​​(relatively) low friction. This may be achieved by providing a so-called matte surface. The area of ​​low friction may cause the sealing surface to seal less tightly against the patient's face than without the low friction area. The area of ​​low friction may be provided as part of the tether 3110 to allow the sides of the patient's nose to slide freely along the sealing surface 3105 and / or the tether 3110.

[0176] 8A-8G also show various cross sections of FIG. 6, where the intersections of the cross sections indicate that the seal-forming structure 3100 includes various saddles and hemispheres. For simplicity, the intersections of the various cross sections are referred to herein by a combination of two letters. For example, the intersection of a cross section taken along line 8A-8A and a cross section taken along line 8B-8B is referred to as intersection AB.

[0177] The intersection AB is taken at a first dome region configured to contact the patient's nasal ridge below the patient's serion. The intersection AC is taken at a first saddle region configured to contact the patient's nasal ridge at a location below the intersection AB. The intersection AD is taken at a second saddle region configured to contact the patient's lower lip and / or chin. The intersection EF is taken at a second dome region configured to contact the patient outside and near the patient's oral cavity near the corners of the mouth. The intersection EG is taken at a third saddle region configured to contact the patient's cheek adjacent the patient's ala. In relation to each other, the first dome region has a relatively large curvature along both cross sections and the second hemisphere region has a relatively small curvature along both cross sections. The first saddle region has a relatively large curvature along both cross sections and the third saddle region has a relatively small curvature along line 8E-8E and a relatively large curvature along line 8G-8G. The second saddle region has a curvature between the first and third saddle regions along line 8D-8D, as does line 8A-8A along line 8G-8G.

[0178] 9 illustrates a further aspect of the present technology. For example, instead of having the tether 3110 continuous with the sealing surface 3105, FIG. 9 illustrates placing the tether 3110 on the underside of the sealing surface 3105. The tether 3110 is illustrated primarily as a dashed line. This configuration may be achieved by attaching or forming a strip or tube of material on the underside of the sealing surface 3105. The underside tether 3110 may be more readily apparent from FIG.

[0179] FIG. 9 also shows a flap 3150. The flap 3150 may extend primarily from the tether 3110 and / or sealing surface 3105 adjacent the patient's nose. Such a flap 3150 may aid in sealing and / or comfort of the patient's nose adjacent the upper maxilla and canthus area. With some known devices, it may be difficult to seal this area of ​​the patient's face. Alternatively, the flap 3150 may extend from the tether 3110, thereby fixing the position of the flap 3150 relative to the tether 3110. FIG. 11 is a simplified view of the tether 3110 as a substantially tubular structure 3120 with the flap 3150 extending from the interior.

[0180] Figure 12 is a simplified diagram of the substantially tubular structure 3120 shown in Figure 11 attached to the seal-forming structure 3100. According to Figure 12, the substantially tubular structure 3120 can be made separately and fastened to the seal-forming structure 3100.

[0181] 13 illustrates how the seal-forming structure 3100 can obtain compliance from the substantially tubular structure 3120 to conform to the patient's face. Even when compliant, the technology can prevent bursting.

[0182] Rupture may be understood to refer to deformation of the seal-forming structure 3100, at least partially due to pressure differentials when pressure is applied during treatment to displace the sealing surface 3105 from sealing contact with the patient's face. For example, a patient may pull the patient interface 3000 away from their face during treatment (i.e., during pressure application), and as the patient interface 3000 is displaced by the patient from the patient's face, the seal-forming structure 3100 may deform due to the force of the treatment pressure. Then, when the patient reapplies the patient interface 3000 to the patient's face, the sealing surface 3105 of the seal-forming structure 3100 may displace due to deformation, resulting in an ineffective seal and pressurized gas leaking from the seal-forming structure 3100. Upon repositioning the seal-forming structure 3100, the internal pressurization of the plenum chamber 3200 may be disrupted, and a pressure gradient may approach the sealing flap 3125. Forces may be generated due to the pressure gradient, which may ultimately result in the sealing flap bursting. Displacement of the sealing flap upon rupture disrupts the seal because the sealing flap may move and create a leak path when the sealing structure is repositioned on the face. If rupture of the seal-forming structure 3100 occurs near the patient's eye (e.g., the sealing surface 3105 near the frontal process of the maxilla is displaced), pressurized gas may flow toward the patient, which may be particularly disruptive and embarrassing for the patient. Thus, it would be advantageous to be able to reduce rupture.

[0183] Rupture from deformation in the seal-forming structure 3100 may occur outward (e.g., away from the patient's face), and in fact, in extreme conditions of high internal pressurization, rupture may cause the seal-forming structure 3100 to double fold backwards.

[0184] The side and lateral cartilages of the nose near the frontal process of the maxilla, including the superior nasal bone, can vary greatly depending on the user's profile. Furthermore, to seal this area, the inner edge of the sealing flap 3125 is bent inward (e.g., toward the plenum chamber and perpendicular to the Frankfurt horizontal) and deformed to follow the profile of the side of the nose. This makes this area particularly susceptible to sealing failure leading to rupture. That is, if the sealing flap 3125 is displaced outward (e.g., away from the patient's face) during rupture, it is often difficult to return the sealing flap to a sealing position due to resistance from the pressurized gas force.

[0185] However, rupture may also occur in areas such as the cheek regions or upper or lower lip regions where seal disruption is less likely, but which generally have a flatter profile substantially along the frontal plane. During rupture, the sealing flaps may move significantly from the position required for sealing along this plane, and the sealing force applied from the headgear vector is often sufficient to reposition the sealing flaps to the required orientation to reacquire a seal.

[0186] The rear surface of the sealing flap, which runs from the side of the nose area down to the lower corner of the sealing flap, provides a larger surface area that is more susceptible to displacement under internal pressure.

[0187] A dual walled seal-forming structure 3100 may be more susceptible to rupture, for example the single walled seal-forming structure 3100 disclosed in one embodiment of the present technology is particularly susceptible to rupture. It may be appreciated that without an undercushion structure to support the outer seal wall, the outer seal wall may more easily deform and distort. Additionally, the presence of an undercushion in a dual walled cushion may assist in repositioning the outer seal wall against the patient's face upon repositioning of the patient interface 3000, which may not be the case in a single walled cushion.

[0188] Figures 34A and 34B show an example of a related art patient interface 3000 in which a rupture has occurred. In Figure 34A, it can be seen how the seal-forming structure 3100 can be deformed such that the sealing surface 3105 in the ruptured area BR1 is displaced from the patient's nose. Furthermore, it can be seen how the seal-forming structure 3100 can be deformed such that the sealing surface 3105 in another ruptured area BR2 is displaced from the side of the patient's nose (e.g., adjacent the frontal process of the maxilla) (see Figure 2H). Similarly, Figure 34B shows the displacement of the sealing surface 3105 of the seal-forming structure 3200 in the ruptured area BR2 to the side of the patient's nose (e.g., adjacent the frontal process of the maxilla).

[0189] In both of the above rupture examples, the patient interface 3000 is a full face patient interface, which seals around the nose and oral cavity. Such patient interfaces are particularly susceptible to rupture because the relatively elongated lateral portions in the middle regions are somewhat less supported and rupture may occur within these regions. Furthermore, the force vectors of the positioning and stabilizing structure 3300 may be oriented generally parallel to the Frankfurt horizontal or sagittal plane. As such, these force vectors may not be directed to impart forces to the seal-forming structure 3100. The seal-forming structure 3100 is oriented generally perpendicularly inwardly to the frontal process of the maxilla, which resists deformation of the seal-forming structure 3100 that would cause rupture. In other words, the therapeutic pressure forces that cause deformation of the seal-forming structure 3100 may have a magnitude and direction that does not adequately oppose the force vectors from the positioning and stabilizing structure 3100. It should be understood that although the rupture phenomenon may be particularly relevant to full face patient interfaces, nasal patient interfaces are also susceptible to rupture by the same principles. Thus, the tethers 3110 disclosed herein can be used with nasal and full face patient interfaces to resist bursting.

[0190] Further, there is a relevant distinction in the context of the sealing surface 3105. The sealing surface 3105 may be understood to refer broadly to the area on the seal-forming structure 3100 where a seal is intended to occur. Since the anthropometric measurements of each patient's head and face are different, the seal-forming structure 3100 may be shaped and sized to provide a comfortable fit and effective seal for a range of patients. Thus, it should be understood that a seal is intended to occur on various areas of the seal-forming structure 3100, and the sealing surface 3105 may refer broadly to such areas. After the seal-forming structure 3100 is actually applied to a particular patient in use, a seal may form at a particular location of the broader area where a seal is intended to occur. The area where a seal actually occurs in use may also be understood as the sealing surface 3105. The particular meaning of the sealing surface 3105 may be understood as subject to the particular context in which the term is used, as described above.

[0191] Returning to the blowout discussed above, blowout occurrence may be understood to refer to a situation in which the sealing surface 3105 where a seal is intended to occur is displaced from the patient's face. If such a displacement occurs, it may at the very least prevent an effective seal, or more simply, prevent sealing contact from occurring altogether.

[0192] FIG. 14 shows another embodiment of the present technology that may prevent rupture of the seal-forming structure 3100. Here, two ribs 3155 are shown, but any number of ribs may be provided. For example, a single rib or three or more ribs may be provided. Like the tethers 3110, each rib 3155 tends to prevent rupture of the seal-forming structure 3100 (e.g., the sealing surface 3105). The ribs may be the same thickness or different thicknesses. For example, one or both ribs 3155 may be about 1 mm thick and one or both ribs 3155 may be about 0.5 mm thick. Alternatively, the ribs may have variable thickness. The sealing surface 3105 may be convex where the ribs 3155 are attached and concave where the opposing ribs 3155 are attached. Thus, the convex and concave surfaces define the thickness of the material in that area. The ribs 3155 may be provided adjacent the patient's nose.

[0193] FIG. 15 shows a cross section of the seal-forming structure 3100 taken perpendicular to the plane of the ribs 3155. The ribs 3155 can be relatively compliant when compressed or can easily collapse under sealing loads, allowing the seal-forming structure 3100 and / or the sealing surface 3105 to conform to the patient's face. This is shown in FIG. 16. However, as shown in FIG. 17, the ribs 3155 can provide a relatively high resistance to tension that may occur when the inside of the seal-forming structure 3100 (e.g., the surface 3105a facing the sealing surface 3105) is pressurized. In this way, the ribs 3155 can tend to resist bursting of the seal-forming structure 3100 (e.g., the ribs 3155 can be tensile members). For example, the ribs 3155 tend to hold the seal-forming structure 3100 in an "as-formed" state or in a shape under bursting conditions.

[0194] The extension flap 3160 shown in Figures 18 and 19 may allow the distance D1 vs D2 to be increased to accommodate facial variations when the distance between the sides of the nose and the sealing flap changes. The sealing surface 3105 of the extension flap 3160 may also provide an effective seal against the cheek. The arrows indicate areas of possible patient contact. This type of structure is primarily sealed with a membrane on a conventional silicone mask, which is prone to rupture upon re-adjustment of the mask position. The tethers 3110 or ribs 3155 may prevent rupture from occurring while allowing for distance changes due to facial differences to effectively seal.

[0195] Figure 20 shows a similar view to Figure 6, except that patterns are included on the seal-forming structure 3100. These patterns show regions 3175 of similar thickness of the seal-forming structure 3100.

[0196] Region 3175A may be a relatively thin region (e.g., about 0.3 mm). This region may be made thin and compliant for comfort at the bridge of the nose.

[0197] Region 3175B can be a very thin region (e.g., about 0.2 mm). By reducing the thickness relative to region 3175A, tension can be significantly reduced, which can result in minimal facial marking at the bridge of the nose, which is a bony area for most patients and therefore prone to marking and / or discomfort.

[0198] Region 3175C can be a semi-thin region (e.g., about 1 mm). This region can be semi-thinned to prevent pinching on the sides of the nose.

[0199] Region 3175D may be a semi-thick region (e.g., about 1.5 mm). This region may seal against the cheeks along the nose. This area on the face typically has more fat than the sides of the nose or bridge, so a relatively large sealing force may be applied without discomfort. The semi-thick region may also provide more structural rigidity than thinner regions.

[0200] The region 3175E may be a thicker region (e.g., about 2.0 mm). This thicker peripheral region may provide a stiffer outer wall to support the inner portion of the cushion. The region 3175E may function like an undercushion in a conventional dual-layer cushion design, for example, the region 3175E may support the portion(s) of the seal-forming structure 3100 that contacts the patient's face. For example, the region 3175E may provide support to the regions 3175D and / or 3175F (discussed below). The overall cross-sectional shape of the cushion may be curved to provide an air (pressure) assisted spring for sealing and compliance. In this configuration, the disclosed configurations including such thicker regions may be advantageous over prior thicker undercushions of conventional masks, since they may also be compressed to provide a level of compliance to assist in seal formation. As a result, it may be possible to increase the overall range of distances over which the cushion can be compressed compared to conventional dual-layer designs.

[0201] Region 3175F can be a thin membrane region (e.g., about 0.3-0.5 mm). The portion that seals under the lower lip can be thin (e.g., about 0.3 mm) to allow for mandibular movement. Such a thin membrane region can also reduce stress on the patient's gums for comfort. This portion of region 3175F adjacent region 3175D is where the tether 3110 is placed. This portion of region 3175F is thin (e.g., about 0.5 mm) to allow for compression of the tether 3110. The portion of region 3175F that is configured to contact over the side of the patient's mouth can be about 0.5 mm and acts like a sealing membrane layer of a dual layer cushion, which maintains a seal with minor changes in facial profile and movement during sleep.

[0202] Although distinct lines are shown between regions 3175, the boundaries between the regions are approximations since the regions may have a smooth transition in relative thickness between them. This may be advantageous because it may improve aesthetics since the naked eye may have a limited ability to distinguish between thick and thin regions. However, distinct transitions may also be provided.

[0203] A cushion is disclosed in International Patent Publication WO2006 / 074513, the entirety of which is incorporated herein by reference. In such a cushion, a thicker undercushion and a thicker membrane layer are disclosed. The thicker membrane relieves (i.e. expands) the seal on the face under pressure, and the undercushion provides support to support the seal. The curved cross section provides a pressure assist spring to support the seal under headgear tension.

[0204] In contrast, the seal-forming structure 3100 with one or more of the above-mentioned regions 3175 may have only a single layer. This single layer may combine the functions of the membrane and undercushion of WO2006 / 074513. The maximum cross-sectional thickness of the region 3175 (e.g., region 3175E) may be thinner than the maximum thickness of the undercushion of WO2006 / 074513. However, the combination of the undercushion and membrane into a single layer provides sufficient structural rigidity to maintain the cushion shape and supportive sealing action. Furthermore, the reduced maximum thickness allows the single layer of the seal-forming structure 3100 to compress over a greater distance than a conventional dual-layer design, thereby increasing compliance before bottoming out.

[0205] In the mask provided in the system disclosed in International Patent Publication WO2014 / 117227, the foam cushion is supported by a flexible clip attached to a second rigid clip, each of which is incorporated herein by reference in its entirety. In a similar system disclosed in FIG. 21, two ribs 3155 are employed. These ribs are configured to be provided on opposite sides of the patient's nose. Only one rib is shown in FIG. 21. These ribs act as ties to prevent rupture of the flexible clip and attached foam seal. Although ribs 3155 are shown, tethers 3110 may be used in place of ribs 3155.

[0206] Thus, in another embodiment of the present technology, the seal-forming structure 3100 includes a cushion 3810 that may be constructed of foam. The cushion defines a single area that covers the patient's nose area in the case of a nasal mask, and the nose and oral area in the case of a full face mask. The foam cushion may be constructed of any suitable material, for example, one or more of polyethylene, polyurethane, ethylene vinyl acetate (EVA). In some cases, the foam cushion may be a semi-open closed cell foam (e.g., made of polyurethane). The semi-open cell foam cushion may have limited permeability (e.g., to the extent described in more detail in International Patent Application Publication WO2014 / 117227). The permeability disclosed therein is incorporated herein by reference.

[0207] The cushion 3810 may have a substantially triangular or pear-shaped shape with a sealing surface that follows the contours of the user's face. The foam cushion is designed to be attached to a first support (e.g., flexible) clip 3812, which itself is attached to a second stiff clip 3814 (as shown in FIG. 22) or directly to the mask shell 3816. In one embodiment, the first support clip 3812 may be a flexible clip, stiffer than the foam cushion and more flexible than the second clip 3814. It is the combination of the foam and the flexible clip that defines the physical characteristics of the overall sealing interface. The flexible clip allows the interface to accommodate large variations and to better conform to the contours of the patient's face. The compliant nature of the foam cushion allows for fine adjustments and creates a comfortable interface layer that interacts with the patient's skin.

[0208] The first support clip 3812 may be prone to rupture due to its flexibility and compliance. Another aspect of the technology shown in FIG. 21 may prevent rupture of the first support clip 3812 and attached cushion 3810. Here, the illustrated configuration includes two ribs 3155 (only one of which is shown due to symmetry and orientation of the drawing), but any number of ribs may be provided. For example, a single rib or three or more ribs may be provided. Similar to the tether 3110, each rib 3155 tends to prevent rupture of the first support clip 3812 and attached cushion 3810 by functioning as a tension member. The ribs may be of the same thickness or different thicknesses. For example, one or both ribs 3155 may be about 1 mm thick and one or both ribs 3155 may be about 0.5 mm thick. Alternatively, the ribs may have variable thicknesses. The ribs 3155 may be provided adjacent the patient's nose.

[0209] 21 shows a side view of the cushion assembly 3800. The cushion assembly 3800 includes a seal-forming structure 3100. The seal-forming structure 3100 includes a mask shell 3816, a permanently attached flexible first support clip 3812, and a foam cushion 3810. As shown, the flexible first support clip may be secured to the mask shell 3816 via a pair of ribs 3155 that act as ties to prevent bursting. These ribs 3155 may be relatively compliant in compression or may easily collapse under sealing loads, allowing the seal-forming structure 3100 to conform to the patient's face. Adjustment of the tension provided by the ribs 3155 may be accomplished by altering any one or more of the material composition, geometry, or position of the ribs 3155.

[0210] Figure 23 shows the foam cushion 3810, with the patient contact surface visible, and the flexible first support clip 3812. Figure 23A is a cross section along a vertical plane of symmetry taken through Figure 23, showing the foam cushion, the flexible first support clip 3812, and the ribs 3155.

[0211] In another embodiment of the present technology, the seal-forming structure 3100 may include a pair of tethers 3110 to prevent rupture of the first support clip 3812. Each tether 3110 is formed by an inward bending of the circumferential flexible support clip 3812, thereby forming a connection point 3165. In this manner, the tethers 3110 may form a substantially tubular structure 3120. The tethers form a tether that resists rupture from internal pressurization of the plenum chamber. The tension provided by the ribs 3155 may be adjusted by altering any one or more of its material composition, geometry or location of the connection point 3165 of the tethers 3110.

[0212] Figures 24A-27F show a cushion assembly 6000 which is similar to the seal-forming structure 3100 except as described hereinabove. Like reference numerals are the same as those described above for the seal-forming structure 3100 and will not be described in further detail. The cushion assembly 6000 shown in Figures 24A-27F may have characteristics which make it primarily suitable for use with a nasal mask.

[0213] FIG. 24A is a perspective view of one form of the cushion assembly 6000 separated from the remainder of the patient interface 3000. FIG. 24B is a perspective view of the cushion assembly 6000 including the shell 6005. The cushion assembly 6000 and the shell 6005 together may form the plenum chamber 3200. The cushion assembly 6000 may be attached to the shell 6005 by any means (e.g., chemical bonding, mechanical connection, or adhesive). In addition, the cushion 6000 may be detachable from the shell 6005 or may be permanently attached to the shell 6005. The cushion assembly 6000 may also be more flexible than the shell 6005. For example, the cushion assembly 6000 may be made of a silicone material and the shell 6005 may be made of a polycarbonate material. It is contemplated that a portion or the entire cushion assembly 6000 may be frosted and the shell 6005 may be transparent. Alternatively, the cushion assembly 6000 and the shell 6005 may be entirely transparent.

[0214] The cushion assembly 6000 may include an elastomeric seal-forming structure 6010 and an elastomeric support structure 6015 that supports the seal-forming structure 6010. The seal-forming structure 6010 may be more flexible than the support structure 6015, which may be more flexible than the shell 6005.

[0215] The seal-forming structure 6010 may include a sealing flap 3125 and may be configured to form a seal around the patient's airway. The seal may be formed around the patient's nose or the patient's nose and oral cavity. In addition, the seal-forming structure 6010 may form a central opening (or rear central opening) 6020 on the rear side of the cushion assembly 6000, which allows access through the cushion 6000 to the interior of the plenum chamber 3200.

[0216] 24A and 24B, the tether 3110 is anchored to the support structure 6015 at attachment points 3145. Additionally, the interior of the plenum chamber 3200 and the tubular structure 3120 formed by the tether 3110 and the cushion assembly 6000 may be bounded by the same inner surface of the seal-forming structure 6010. In other words, the tubular structure 3120 and the plenum chamber 3200 may be bounded by a common surface of the cushion assembly 6000.

[0217] Figures 25B-25G also show various cross sections of Figure 25A, where the intersections of the cross sections show that the seal-forming structure 6010 includes various saddles and hemispheres. For simplicity, the intersections of the various cross sections are referred to herein by a combination of two letters. For example, the intersection of the cross section taken along line 25B-25B and the cross section taken along line 25C-25C are referred to as intersection BC.

[0218] The intersection BC is taken at a first saddle region configured to contact the patient's nasal ridge below the patient's selion. Along line 25B-25B, the curvature is relatively small, and along line 25C-25C, the curvature is relatively large. The curvature along line 25B-25B is large enough to allow the first saddle region to approximate a cylindrical region. If desired, the first saddle region may be a cylindrical region. The intersection BD is taken at a second saddle region configured to contact the patient's upper lip. Along line 25B-25B, the curvature is relatively smaller than along line 25D-25D. The intersection CF is taken at a first dome region configured to contact the patient's nose adjacent the nasal ridge. Along lines 25F-25F and 25C-25C, the curvature is relatively similar. The intersection FG is taken at a third saddle region formed by the tether 3110 configured to contact the patient's nose alongside. The curvature along line 25F-25F is relatively small and approaches zero curvature. The curvature along line 25G-25G is relatively large compared to line 25F-25F. Thus, the third saddle region is close to a cylindrical region and may be a cylindrical region if preferred. The intersection EF is taken at a second dome region configured to contact the patient alongside the patient's ala. The curvature along lines 22E-22D and 22F-22F are relatively similar.

[0219] Figures 27A and 27B show views of the seal-forming structure 6010, except that there are patterns provided on the seal-forming structure 6010. These patterns designate similar properties and / or thicknesses of the seal-forming structure 6010. Figure 27B shows the positional relationship between the tethers 3110 and the different regions.

[0220] When the patient interface 3000 is fitted on the patient's face, the region 6010A (which may be referred to as the nasal bridge region) may engage the patient's nasal bridge. Additionally, the region 6010A may extend from the central opening 6020 to the support structure 6015.

[0221] Because the elastomeric wall thickness of the seal-forming structure 6010 is thinnest in region 6010A, the seal-forming structure 6010 may be most compliant on the patient's nose bridge. For example, the elastomeric wall thickness of the seal-forming structure 6010 in region 6010A may be about 0.25 mm. As a result, the seal-forming structure 6010 may be facilitated in reducing red marks adjacent the patient's nose bridge. However, because the seal-forming structure 6010 is thin in region 6010A, the portion of the seal-forming structure 6010 in region 6010A may not be able to maintain its shape when subjected to forces generated when the patient interface 3000 is pressed against the patient's face and may move relative to the patient's face (as may occur during a treatment session). As such, the thinness of the seal-forming structure 6010 in region 6010A may make the portion of the seal-forming structure 6010 in region 6010A more susceptible to wrinkles and / or folds, which may result in leakage and / or discomfort.

[0222] A pair of regions 6010B (which may be referred to as spring regions or nasal bridge support regions) may flank region 6010A. Regions 6010B may extend from the support structure 6015 short of the central opening 6020 such that a first end 6025 of each region 6010B may be anchored in place and a second end 6030 of each region 6010B may be free to move in response to compressive forces acting on the seal-forming structure 6010.

[0223] The elastomeric wall thickness of each region 6010B may vary between the first end 6025 and the second end 6030. The elastomeric wall thickness of the region 6010B may be thickest at the first end 6025 and thinnest at the second end 6030. For example, the elastomeric wall thickness at the first end 6025 may be about 1.35 mm and the elastomeric wall thickness at the second end 6030 may be about 0.9 mm. It is contemplated that the elastomeric wall thickness of the seal-forming structure 6010 in each region 6010B may taper from the first end 6025 to the second end 6030 or may change abruptly from the first end 6025 to the second end 6030. In any event, the elastomeric wall thickness of the seal-forming structure 6010 throughout each region 6010B may be thicker than the elastomeric wall thickness of the seal-forming structure 6010 in region 6010A.

[0224] The region 6010B may be separate from the ribs that are structured to provide overall support for the cushion. For example, the curvature of the seal-forming structure 6010 in the region 6010B may be different from the curvature (or lack of curvature) of the ribs. For each point in the region 6010B, the inner surface of the seal-forming structure 6010 (the surface facing and bounding the plenum chamber 3200) and the outer surface of the seal-forming structure 6010 (the surface facing the inner surface and facing away from the plenum chamber 3200) may have opposite types of curvature. For example, if the inner surface of the seal-forming structure 6010 at a particular point in the region 6010B has a positive curvature, the outer surface of the seal-forming structure 6010 at the same point in the region 6010B has a negative curvature. The same is true if the inner surface has a negative curvature. In other words, the curvature of the inner surface may follow the curvature of the outer surface.

[0225] The seal-forming structure 6010 may be constructed such that the radius of curvature of the seal-forming structure 6010 is reduced from a "neutral radius of curvature" in response to a compressive force acting on the seal-forming structure 6010. The seal-forming structure 6010 in each region 6010B may "bounce" back to the neutral radius of curvature in the absence of a compressive force.

[0226] The "spring action" of region 6010B may provide support for region 6000A, which may prevent or reduce wrinkling and / or folding at the site of the seal-forming structure 3110 in region 6010A. In particular, by reducing the elastomeric wall thickness in region 6010A, the seal-forming structure 6010 in region 6010A may not be able to provide resistance to wrinkling and / or folding when the seal-forming structure 6010 is pressed against the patient's face and / or when the seal-forming structure 6010 moves or rubs on the patient's face due to the patient's movements while sleeping. The "spring force" provided by region 6010B may act against the "plane of the patient's face" and / or against the sides of the patient's nose. Because region 6010B is positioned alongside region 6010A, the "spring force" generated by region 6010B may provide sufficient support to region 6010A to allow region 6010A to at least partially withstand wrinkles and / or folds. Region 6010B may also enable region 6010A to maintain a seal with the patient's face in the event that region 6010A has any wrinkles and / or folds, thereby allowing the cushion assembly 6000 to maintain a seal with the patient's face while providing increased comfort.

[0227] A pair of regions 6010C (which may be referred to as compliant regions) are positioned side-by-side with region 6010B such that each region 6010B is sandwiched between region 6010A and region 6010C. Similar to region 6010B, the elastomeric wall thickness of the seal-forming structure 6010 in each region 6010C may vary such that region 6010C tapers from the support structure 6015 to the central opening 6020. It should be understood that the elastomeric wall thickness of the seal-forming structure 6010 in region 6010C may be thicker toward the support structure 6015 and thinner toward the central opening 6020. For example, the elastomeric wall thickness in region 6010C may vary from about 0.25 mm adjacent the central opening 6020 to about 1.30 mm adjacent the support structure 6015. Where region 6010B meets region 6010C, the elastomeric wall thickness in region 6010B can always be thicker than the corresponding elastomeric wall thickness in region 6010C. Additionally, the transition from the thickest elastomeric wall thickness to the thinnest elastomeric wall thickness can be abrupt or gradual.

[0228] A pair of regions 6010D (which may be referred to as membrane regions) may be directly adjacent to the central opening 6020. Additionally, region 6010D may have the same thickness as region 6010A (i.e., approximately 0.25 mm) and thus may function as a biased (e.g., pressure activated) seal against the patient's face. The pair of regions 6010D may form approximately 1 / 3 of the seal-forming structure 6010 and may include the tether 3110.

[0229] Region 6010E (which may be referred to as the lip region) may be configured to engage the patient's face above the patient's upper lip. As shown, the cushion assembly 6000 in this region may be curved to avoid digging into the patient's upper lip. In addition, region 6010E may have the same thickness as regions 6010A and 6010D (i.e., about 0.25 mm). This allows the seal-forming structure 6010 to be more compliant with the region adjacent the patient's upper lip. In addition, similar to region 6010A, region 6010E may extend from the central opening 6020 to the support structure 6015. As such, regions 6010A, 6010D, and 6010E may together form a continuous membrane layer from the underside of the seal-forming structure 6010 to the top side of the seal-forming structure.

[0230] A pair of regions 6010F (which may be referred to as "undercushion" regions) may be the primary regions of the seal-forming structure 6010. Region 6010F may have the same function as the undercushion layer has in a "dual-wall" cushion (i.e., providing support for the membrane), in a "single-wall" cushion assembly 6000. In the case of the cushion assembly 6000, region 6010F may support regions 6010D and 6010E, where the elastomeric wall thickness is at its thinnest.

[0231] The elastomeric wall thickness of the seal-forming structure 6010 in region 6010F may vary. In particular, the elastomeric wall thickness may increase towards the support structure 6015. For example, the elastomeric wall thickness in region 6010F may be about 1.0 mm adjacent regions 6010D and 6010E and about 2.0 mm adjacent the support site 3125. The change in elastomeric wall thickness may be abrupt or gradual.

[0232] Region 6010G (which may be referred to as a side support region) may have the greatest elastomeric wall thickness of any region of seal-forming structure 6010. The elastomeric wall thickness of seal-forming structure 6010 may be between about 1.35 mm and 3.45 mm. For example, the elastomeric wall thickness may be between about 1.35 mm and about 2.00 mm. One or more sub-regions within region 6010G may have an elastomeric wall thickness between about 0.90 mm and about 1.80 mm. It is contemplated that region 6010G may have a constant elastomeric wall thickness or may have a variable elastomeric wall thickness that increases as it approaches support structure 6015. If the elastomeric wall thickness changes, the change in thickness may be abrupt or gradual. Region 6010G may provide support or a base for sealing flap 3125 and may provide or maintain the overall shape of seal-forming structure 6010.

[0233] 27A-27D, the cushion assembly 6000 may be divided into a left side 6035 and a right side 6040 by a sagittal plane 6045. The sagittal plane 6045 may include a line 6050 that is tangent to the seal-forming structure 6010 at only two points (i.e., a first tangent point (upper tangent point) 6055 and a second tangent point (lower tangent point) 6060).

[0234] The region 6010A can straddle the sagittal plane 6045 and can include the first contact point 6055. Also, comparing Figures 27A and 27B with Figures 25B-26G, it can be seen that the portion of the region 6010A that includes the first contact point 6055 can be saddle-shaped.

[0235] The regions 6010B may be symmetrical about the sagittal plane 6045. Additionally, each region 6010B may be furthest from the sagittal plane 6045 at the first end 6025 and closest to the sagittal plane 6045 at the second end 6030. Additionally, at least a portion of each region 6010B may be disposed within a region of the seal-forming structure 6010 that transitions from a saddle shape to a hemispherical shape. Additionally, the regions 6010B may be disposed on a cylindrical portion of the seal-forming structure 6010.

[0236] As can be seen by comparing Figures 25B-25G with Figures 27A and 27B, region 6010C may be hemispherical. Portions of regions 6010F and 6010G may also be hemispherical. The radius of curvature of the hemispherical shape in region 6010C may be smaller than the radius of curvature of the hemispherical shape in region 6010F. Also, portions of regions 6010F and 6010G may be cylindrical.

[0237] Region 6010D can straddle the sagittal plane 6045 and can include the second tangent point 6055. Also, comparing Figures 27A and 27B with Figures 25B-26G, it can be seen that the portion of region 6010D that includes the second tangent point 6055 can be saddle-shaped. It is contemplated that the radius of curvature in region 6010D can be greater than the radius of curvature of region 6010A.

[0238] As shown in FIG. 27E, the seal-forming structure 6010 can have a continuous surface around the central opening 6020. As such, the seal-forming structure 6010 can have a number of closed paths 6065 coaxial with the central opening 6020. For purposes of this disclosure, a path coaxial with the central opening 6020 can substantially follow the shape of the central opening 6020 and can be a particular distance from the central opening 6020 throughout the path when viewed from the front (i.e., when viewed from the perspective shown in FIG. 27E). FIG. 27E also shows one of a number of open paths 6070 extending from the central opening 6020 to the support site 6015.

[0239] 27F and 27L show an example cushion assembly 6000 including a shell 6005. As can be seen, at certain points within the cushion assembly 6000, the seal-forming structure 6010 may overhang the support structure 6015. In these areas, the seal-forming structure 6010 may have a "sickle" shape. This "sickle" shape is more clearly illustrated in the cross-sections shown in FIGS. 27M-R. It should be understood that a cross-section of the cushion along a line (e.g., a line extending through the central region of the cushion as shown in FIG. 27L) may have a closed loop shape in some areas and the cross-section may have an open shape in other areas. In a "closed loop" area, the edges of the cushion may both be fixed in place. In an "open" area, one end of the cushion may be fixed in place and the other end may be a free end, not fixed to anything and allowed to move freely.

[0240] The support structure 6015 may include a pair of flange portions 6075 on opposite sides of a sagittal plane 6045 toward the underside of the cushion assembly 6000. The flange portions 6075 may extend radially outward from the support structure 6015. Additionally, the seal-forming structure 6010 may be attached to an outer edge of the flange portions 6075 such that when a compressive force acts on the seal-forming structure 6010, the flange portions 6075 hinge about the base 6080 of each flange portion 6075. In this manner, each flange portion 6075 may act as a shock absorber when the seal-forming structure 6010 experiences a compressive force (e.g., due to the cushion assembly 6000 being compressed by the patient's head).

[0241] The flexibility of the support structure 6015 may be related to the distance between the front side of the support structure 6015 and the rear side of the support structure. For example, if the distance between the front side and the rear side is shorter, the support structure 6015 may be less flexible (FIGS. 27M and 27R). Conversely, if the distance between the front side and the rear side is longer, the support structure 6015 may be more flexible (FIGS. 27O and 27Q). In other words, because of the varying distance between the front side and the rear side of the support structure 6015, the support structure 6015 may provide more support to the seal-forming structure 6010 at the top and / or bottom of the cushion assembly 6000 than at other locations of the cushion assembly 6000.

[0242] 28A-28M show an exemplary full-face seal-forming structure 3100 including a tether 3110. As seen in FIG. 28K, for example, the tether 3110 can extend between a first inner surface region 3180 and a second inner surface region 3185. The first inner surface region 3180 can be understood to be on the opposite side of the sealing surface 3105 of the seal-forming structure. The second inner surface region 3185 can be understood to be elsewhere. In the embodiment shown in FIG. 28K, the second inner surface region 3185 is disposed on the interior of the seal-forming structure 3100. In other embodiments, the second inner surface region 3185 can be disposed on the interior of the plenum chamber 3200 such that the tether 3110 extends between the seal-forming structure 3100 and the plenum chamber 3200. The location of the second inner surface region 3185 can be selected based on a desired directional component of the tensile vector of the tether 3100 to withstand a burst force.

[0243] 28L and 28M are detailed cross-sectional views, specifically showing the connection point 3165 where the tether 3110 extends from the second inner surface region 3165. The connection point 3165 in this embodiment may be curved to reduce stress concentrations in this area, thereby reducing the tendency of the tether 3110 to break. Additionally, the tether 3110 may extend from the second inner surface region 3185 a distance from the bond area 3190 where the seal-forming structure 3100 is bonded to the plenum chamber 3200 during manufacture. This may prevent damage to the tether 3110 when bonding the seal-forming structure 3100 to the plenum chamber 3200. FIGS. 29C-29E also show how the tether 3110 extends from the second inner surface region 3185 a distance from the bond area 3190 and the plenum chamber 3200.

[0244] The cross-sectional views of Figures 28J-L also show that the tether 3110 can extend from the first inner surface region 3180. As can be seen in these examples, the tether 3110 extends from the first inner surface region 3110 at a location adjacent to, but not at, the closure flap 3125. However, in other examples, the tether 3110 can extend from the first inner surface region 3180 closer to or at the edge of the closure flap 3125.

[0245] 30A and 30B show an example of a full-face patient interface 3000 that includes a seal-forming structure 3100 incorporating features of the present technology and does not include the positioning and stabilizing structure 3300 described.

[0246] 31A-31M show another embodiment of the present technology which is a nose seal forming structure 3100. As can be seen in Fig. 31K, for example, the tether 3110 extends proximate to the sealing flap 3125. As such, there may not be a defined edge in this area. Furthermore, it should be appreciated that at least a portion of the tether 3110 in such an arrangement may form part of the sealing surface 3105 in use depending on the anthropometry of the patient's face.

[0247] 32C-32E illustrate that in an embodiment of a nasal patient interface 3000, the tether 3110 may extend from the second inner surface region 3185 a further distance from the bond region 3190 as compared to the full face patient interface 3000. FIG.

[0248] 33A-33C show that the frame (or shroud) 6085 can function as a hub for the entire patient interface system. In particular, the frame 6085 can be removably connected to the shell 6005, which in turn is removably connected to the stabilizing structure 3300. In addition, the frame 6085 can be removably connected to the air circuit 4170. In addition, the shell 6005 can include a flexible lip seal at the central opening. This flexible lip seal can seal the air path from the air circuit 4170 to the plenum chamber 3200. With the modular configuration using the frame 6085 as a focus, the cushion assembly 6000 and shell 6005 can be interchangeable with other cushion assemblies 6000 and shells 6005. In addition, the modular configuration allows for removal of the patient interface system without the need for adjustment of the support structure 3300.

[0249] 35 shows another exemplary sealing structure 7000. Region 7005A, referred to herein as the nasal region, may be approximately 0.5 mm thick, thereby preventing wrinkling and / or puckers of the seal-forming structure 7000 in this region.

[0250] Region 7005B, referred to herein as the base region, may be about 2.9 mm to 3.45 mm thick. For example, the thickness may be 2.9 mm in 7005B2, 3.0 mm in 7005B1 and 7005B3, and 3.45 mm in 7005B4. Region 7005B may provide support or a base for the sealing flap 3125 and may provide and maintain the overall shape of the seal-forming structure 7000.

[0251] Region 7005C, referred to herein as the undercushion zone, may have a thickness between 0.95 mm and 2.1 mm. As shown, this region may be the majority of the cushion. For example, region 7005C may be approximately 50% of the cushion. The thickness of the top of region 7005C1 may be between 0.95 mm and 1.6 mm, and the thickness of the bottom of region 7005C2 may be between 1.25 mm and 2.1 mm. The thickness may vary continuously between these values ​​to provide a smooth appearance.

[0252] Region 7005D, referred to herein as the membrane region, may form approximately one-third of the seal-forming structure 7000 and may include the tether 3110. The thickness may be approximately 0.35 mm. This region may be relatively thin so that it can act as a biased (e.g., pressure-activated) seal against the patient's face. Side 7005D1 may be substantially parallel to the patient's face so that the likelihood of puckers and resulting leakage is reduced. Such wrinkling is more likely in dynamic situations (e.g., when the seal is in motion).

[0253] Region 7005F, referred to herein as the spring zone, may have a thickness of 1.1 mm to 1.8 mm. This zone may act as a spring, allowing compression on the upper lip to reduce pressure on the upper lip. This region may be progressively stiffer from the center of the upper lip (where the stiffness of 7005F is highest from the center of the region) to the corners of the nose (e.g., the alar apex).

[0254] Region 7005G may be referred to herein as the nasal recess region and may be made deeper to better accommodate patients with a higher nasal bridge and / or to make the seal more comfortable. This region may have a similar thickness to region 6005D (e.g., about 0.35 mm) and may therefore be a sub-region of region 7005D.

[0255] The terms "soft" and "flexible" and their derivatives, when used herein to describe the first support clip 3812, are intended to have the meaning of the term "elastic", as specifically defined in the "Terminology Used in Relation to Patient Interfaces" section, i.e., a flexible support clip is substantially elastically deformable and can release substantially all of its energy rapidly upon unloading.

[0256] The seal-forming structure 3100 may be advantageous in one or more forms of the present technology. For example, human facial structure may vary from person to person, presenting a challenge in designing a seal for use with a multitude of different faces. Such differences include different shapes of facial structure (e.g., differently shaped noses and / or differently curved cheeks) and / or different tissue content (e.g., more or less adipose tissue). Due to these differences, a conventional seal-forming structure may work well for one person and not for another. Also, the perception of comfort may vary from person to person independent of the facial structure. With the seal-forming structure 3100 described herein, a higher percentage of users may effectively use the seal-forming structure 3100 (e.g., a higher percentage of users may have the seal-forming structure 3100 to form an effective seal and / or a higher percentage of users may perceive the seal-forming structure 3100 as comfortable) compared to a conventional seal-forming structure.

[0257] 5.3.2 Plenum chamber

[0258] The plenum chamber 3200 has edges shaped to be complimentary to the surface contours of an average human face in the area where a seal is formed in use. In use, the peripheral edges of the plenum chamber 3200 are positioned proximate to the 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 around the entire edge of the plenum chamber 3200 in use.

[0259] In certain forms of the present technology, the plenum chamber 3200 is constructed from a transparent material (e.g., clear polycarbonate). The use of a transparent material may reduce the intrusiveness of the patient interface and aid in improved compliance with treatment. The use of a transparent material may aid the clinician in seeing the placement and function of the patient interface.

[0260] In certain forms of the present technology, the plenum chamber 3200 is constructed from a translucent material. The use of a translucent material can make the patient interface less intrusive and can help improve compliance with treatment.

[0261] 5.3.3 Positioning and stabilizing structures

[0262] The seal-forming structure 3100 of the patient interface 3000 of the present technology may be held in a sealed position by the positioning and stabilising structure 3300 in use.

[0263] In one form, the positioning and stabilizing structure 3300 provides at least enough retention force to overcome the effect of the positive pressure in the plenum chamber 3200 to lift off the face.

[0264] In one form, the positioning and stabilising structure 3300 provides a retaining force sufficient to overcome the attractive force on the patient interface 3000.

[0265] In one form, the positioning and stabilizing structure 3300 provides a retention force as a safety margin to eliminate the possibility of destructive action on the patient interface 3000 (e.g., due to tube drag or inadvertent interference with the patient interface).

[0266] In one form of the present technology, a positioning and stabilizing structure 3300 is provided that is configured to be worn by a patient while sleeping. In one embodiment, the positioning and stabilizing structure 3300 has a low profile or cross-sectional thickness to reduce the perceived or actual bulk of the device. In one embodiment, the positioning and stabilizing structure 3300 includes at least one strap having a rectangular cross-section. In one embodiment, the positioning and stabilizing structure 3300 includes at least one flat strap.

[0267] In one form of the present technology, a positioning and stabilizing structure 3300 is provided that is configured so as not to be excessively large or bulky in size that would interfere with a patient sleeping in a supine sleep position with the posterior region of the patient's head resting on a pillow.

[0268] In one form of the present technology, a positioning and stabilizing structure 3300 is provided that is configured so as not to be excessively large or bulky in size that would interfere with a patient sleeping in a lateral sleep position with the side region of the patient's head resting on a pillow.

[0269] In one form of the present technology, the positioning and stabilizing structure 3300 includes a strap constructed from a laminate of a textile patient-contacting layer, a foam material inner layer, and a textile outer layer. In one form, the foam material is porous to allow moisture (e.g., sweat) to pass through the strap. In one form, the textile outer layer includes a tie material that engages with a hook material portion.

[0270] In certain forms of the present technology, the positioning and stabilizing structure 3300 includes a stretchable (e.g., stretchable with elasticity) strap. For example, the strap can be configured to be tensioned in use to direct a force that causes the cushion to seal against a portion of the patient's face. In one example, the strap can be configured as a tie.

[0271] In certain forms of the present technology, the positioning and stabilizing structure 3300 includes straps that are bendable, e.g., non-rigid. An advantage of this embodiment is that the straps are more comfortable when the patient lies down to sleep.

[0272] In a particular form of the present technology, the positioning and stabilizing structure 3300 includes straps configured to be breathable to allow water vapor to pass therethrough.

[0273] In certain forms of the present technology, a system is provided that includes more than one positioning and stabilizing structure 3300. Each positioning and stabilizing structure 3300 is configured to provide a holding force to accommodate a range of different sizes and / or shapes. For example, a system may include one form of positioning and stabilizing structure 3300 that is suitable for a large sized head but not a small sized head and another that is suitable for a small sized head but not a large sized head.

[0274] 5.3.4 Ventilation

[0275] In one form, the patient interface 3000 includes a vent 3400 constructed and arranged to allow for the expulsion of exhaled gases (eg, carbon dioxide).

[0276] The ventilation portion 3400 in one embodiment according to the present technology includes a plurality of holes (eg, about 20 to about 80 holes, or about 40 to about 60 holes, or about 45 to about 55 holes).

[0277] The vent 3400 may be disposed within the plenum chamber 3200. Alternatively, the vent 3400 is disposed within a decoupling structure (e.g., a swivel).

[0278] 5.3.5 Decoupling structures(multiple)

[0279] One form of the patient interface 3000 includes at least one decoupling structure (eg, a swivel or a ball and socket).

[0280] 5.3.6 Connection Ports

[0281] The connection port 3600 allows connection to the air circuit 4170 .

[0282] 5.3.7 Forehead support

[0283] In one form, the patient interface 3000 includes a forehead support 3700.

[0284] 5.3.8 Anti-asphyxiation valves

[0285] In one form, the patient interface 3000 includes an anti-asphyxiation valve.

[0286] 5.3.9 Ports

[0287] In one form of the present technology, the patient interface 3000 includes one or more ports that allow access to the volume within the plenum chamber 3200. In one form, this allows a clinician to provide supplemental oxygen. In one form, this allows a characteristic of the gas (e.g., pressure) within the plenum chamber 3200 to be directly measured.

[0288] 5.4 RPT Devices

[0289] An RPT device 4000 according to one aspect of the present technology includes mechanical, pneumatic, and / or electrical components and is configured to execute one or more algorithms 4300. The RPT device 4000 may be configured to generate an airflow that is delivered to a patient's airway for treatment of one or more of the respiratory conditions described anywhere herein, for example.

[0290] The RPT device may have an outer housing 4010 formed as two parts, an upper portion 4012 and a lower portion 4014. Further, the outer housing 4010 may include one or more panel(s) 4015. The RPT device 4000 includes a chassis 4016 that supports one or more internal components of the RPT device 4000. The RPT device 4000 may include a handle 4018.

[0291] The air pressure path of the pneumatic RPT device 4000 may include one or more air circuit items (e.g., an inlet air filter 4112, an inlet muffler 4122, a pressure generator 4140 (e.g., a blower 4142) capable of supplying air at positive pressure, an outlet muffler 4124) and one or more transducers 4270 (e.g., a pressure sensor 4272 and a flow sensor 4274).

[0292] One or more of the pneumatic circuit items may be disposed within a removable unitary structure referred to herein as a pneumatic block 4020. The pneumatic block 4020 may be disposed within the outer housing 4010. In one form, the pneumatic block 4020 is supported by or formed as part of the chassis 4016.

[0293] The RPT device 4000 can have a power supply 4210, one or more input devices 4220, a central controller 4230, a therapy device controller 4240, a pressure generator 4140, one or more protection circuits 4250, a memory 4260, a transducer 4270, a data communication interface 4280, and one or more output devices 4290. The electrical components 4200 can be mounted on a single printed circuit board assembly (PCBA) 4202. In an alternative, the RPT device 4000 can include more than one PCBA 4202.

[0294] 5.4.1 RPT Device Mechanical and Pneumatic Components

[0295] The RPT device may include one or more of the following components in an integral unit: In one alternative, one or more of the following components may be disposed as their own separate units.

[0296] 5.4.1.1 Air filters

[0297] An RPT device according to one form of the present technology may include an air filter 4110 or multiple air filters 4110.

[0298] In one form, the inlet air filter 4112 is positioned at the beginning of the air pressure path upstream of the pressure generator 4140 .

[0299] In one form, an outlet air filter 4114 (eg, antibacterial factor) is located between the outlet of the pneumatic block 4020 and the patient interface 3000.

[0300] 5.4.1.2 Mufflers

[0301] An RPT device according to one form of the present technology may include a muffler 4120 or multiple mufflers 4120.

[0302] In one form of the present technology, an inlet muffler 4122 is positioned above a pressure generator 4140 in the pneumatic path.

[0303] In one form of the present technology, the outlet muffler 4124 is positioned in the pneumatic path between the pressure generator 4140 and the patient interface 3000.

[0304] 5.4.1.3 Pressure generator

[0305] In one form of the present technology, the pressure generator 4140 that generates the air flow or supply 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 housed in a volute. The blower may deliver the air supply at a rate of, for example, up to about 120 liters / min, at a positive pressure ranging from about 4 cmH2O to about 20 cmH2O, or in other forms up to about 30 cmH2O. The blower may be described in any one of the following patents or patent applications, which are incorporated herein by reference in their entirety: U.S. Pat. No. 7,866,944; U.S. Pat. No. 8,638,014; U.S. Pat. No. 8,636,479; and PCT Patent Application Publication WO 2013 / 020167.

[0306] The pressure generator 4140 is under the control of the treatment device controller 4240 .

[0307] In other forms, pressure generator 4140 can be a piston-driven pump, a pressure regulator connected to a high pressure source (eg, a compressed air reservoir), or a bellows.

[0308] 5.4.1.4 Converters

[0309] The transducer may be internal to the RPT device or external to the RPT device. An external transducer may, for example, be located on the air circuit or form part of the air circuit (e.g., a patient interface). An external transducer may take the form of a non-contact sensor (e.g., a Doppler radar movement sensor that transmits or moves data RPT device).

[0310] 5.4.2 RPT Device Electrical Components

[0311] 5.4.2.1 Power supply

[0312] The power supply 4210 may be located inside or outside the external housing 4010 of the RPT device 4000.

[0313] In one form of the present technology, the power supply 4210 powers only the RPT device 4000. In another form of the present technology, power is provided from the power supply 4210 to both the RPT device 4000 and the humidifier 5000.

[0314] 5.4.2.2 Input Devices

[0315] In one form of the present technology, the RPT device 4000 includes one or more input devices 4220 in the form of buttons, switches or dials to allow a human to interact with the device. The buttons, switches or dials may be physical or software devices accessible via a touch screen. The buttons, switches or dials may be physically connected to the external housing 4010 in one form or may communicate wirelessly with a receiver electrically connected to a central controller in another form.

[0316] 5.4.2.3 Optional displays and output devices, including alarms

[0317] Output devices according to the present technology may take the form of one or more of visual, audio and tactile units. The visual display may be a Liquid Crystal Display (LCD) or a Light Emitting Diode (LED) display.

[0318] 5.5 Air Circuit

[0319] An air circuit 4170, according to one aspect of the present technology, is a conduit or tube constructed and arranged such that, in use, air flow travels between two components (eg, the RPT device 4000 and the patient interface 3000).

[0320] In particular, the air circuit 4170 may be fluidly connected to the outlet of the pneumatic block 4020 and the patient interface. The air circuit may be referred to as an air delivery tube. In some cases, there may be separate limbs of the circuit for inhalation and exhalation. In other cases, a single limb is used.

[0321] In some forms, the air circuit 4170 may include one or more heating elements configured to heat the air in the air circuit (e.g., to maintain or increase the air temperature). The heating elements may take the form of a heated wire circuit and may include one or more transducers (e.g., temperature sensors). In one form, the heated wire circuit may be spirally wound around the axis of the air circuit 4170. The heating elements may be in communication with a controller (e.g., a central controller). One example of an air circuit 4170 including a heated wire circuit is described in U.S. Patent Application No. 8,733,349, which is incorporated by reference in its entirety.

[0322] 5.6 Humidifier

[0323] 5.6.1 Humidifier Overview

[0324] In one form of the present technology, a humidifier 5000 is provided for changing the absolute humidity of air or gas to be delivered to a patient relative to the ambient air (e.g., as shown in Fig. 3V and 3W). Typically, the humidifier 5000 is used to increase the absolute humidity (relative to ambient air) and increase the temperature of the air stream before delivery to the patient's airway.

[0325] The humidifier 5000 may include a humidifier reservoir 5110, a humidifier inlet 5002 for receiving an airflow, and a humidifier outlet 5004 for delivering a humidified airflow. In some forms, such as shown in Figures 3V and 3W, the inlet and outlet of the humidifier reservoir 5110 may be the humidifier inlet 5002 and the humidifier outlet 5004, respectively. The humidifier 5000 may further include a humidifier base 5006. The humidifier base 5006 may be adapted to receive the humidifier reservoir 5110 and may include a heating element 5240.

[0326] 5.6.2 Humidifier Components

[0327] 5.6.2.1 Water reservoir

[0328] According to one arrangement, the humidifier 5000 may include a water reservoir 5110 configured to contain or hold a quantity of liquid (e.g., water) to be evaporated for humidification of the air stream. The water reservoir 5110 may be configured to contain a predetermined maximum quantity of water to provide adequate humidification for at least the duration of a respiratory therapy session (e.g., a night's sleep). Typically, the reservoir 5110 is configured to contain several hundred milliliters of water (e.g., 300 milliliters (ml), 325 ml, 350 ml, or 400 ml). In another form, the humidifier 5000 may be configured to receive a water supply from an external water source (e.g., a building's water supply system).

[0329] According to one embodiment, the water reservoir 5110 is configured to humidify the air flow from the RPT device 4000 as the air flow passes through the RPT device 4000. In one form, the water reservoir 5110 may be configured to promote the air flow traveling a tortuous path through the reservoir 5110 while the air flow contacts a volume of water in the reservoir 5110.

[0330] According to one form, the reservoir 5110 may be removable from the humidifier 5000 laterally, for example as shown in Figures 3V and 3W.

[0331] The reservoir 5110 may also be configured to inhibit liquid release from the reservoir 5110, for example, when the reservoir 5110 is displaced and / or rotated from its normal operating orientation (e.g., through any aperture and / or between its subcomponents). Because the air flow to be humidified by the humidifier 5000 is often pressurized, the reservoir 5110 may also be configured to avoid loss of air pressure through leakage and / or flow impedance.

[0332] 5.6.2.2 Conductive Sites

[0333] According to one arrangement, the reservoir 5110 includes a conductive region 5120 configured to allow efficient heat transfer from the heating element 5240 to the volume of liquid in the reservoir 5110. In one form, the conductive region 5120 may be arranged as a plate, although other shapes may be suitable. All or part of the conductive region 5120 may be constructed of a thermally conductive material such as aluminum (e.g., approximately 2 mm (e.g., 1 mm, 1.5 mm, 2.5 mm, or 3 mm) thick), another thermally conductive metal, or some plastic. In some cases, adequate thermal conductivity may be achieved with a less conductive material of appropriate geometry.

[0334] 5.6.2.3 Humidifier Reservoir Dock

[0335] In one form, the humidifier 5000 may include a humidifier reservoir dock 5130 (as shown in FIG. 3V) configured to receive the humidifier reservoir 5110. In some arrangements, the humidifier reservoir dock 5130 may include a locking feature (e.g., a locking lever 5135 configured to hold the reservoir 5110 within the humidifier reservoir dock 5130).

[0336] 5.6.2.4 Water Level Indicator

[0337] The humidifier reservoir 5110 may include a water level indicator 5150 as shown in Figures 3V-3W. In some forms, the water level indicator 5150 may provide one or more indications to a user, such as the patient 1000 or a caregiver, about the amount of water in the humidifier reservoir 5110. These one or more indications provided by the water level indicator 5150 may include an indication of a maximum predetermined amount of water, any portion thereof (e.g., 25%, 50% or 75% or an amount (e.g., 200ml, 300ml or 400ml)).

[0338] 5.6.2.5 Heating elements

[0339] In some cases, a heating element 5240 may be provided to the humidifier 5000 to provide heat input to one or more of the volume of water in the humidifier reservoir 5110 and / or the volume of water to the airflow. The heating element 5240 may include a heat-generating component, such as an electrical resistance heating track. One suitable example of the heating element 5240 is a layered heating element, for example, as described in PCT Patent Application Publication No. WO2012 / 171072, the entirety of which is incorporated herein by reference.

[0340] In some forms, the heating element 5240 may be mounted in the humidifier base 5006. In the humidifier base 5006, heat may be transferred to the humidifier reservoir 5110 primarily by conduction, as shown in FIG.

[0341] 5.7 Glossary

[0342] For purposes of this disclosure, in certain aspects of the technology, one or more of the following definitions may apply. In other aspects of the technology, other definitions may apply.

[0343] 5.7.1 General

[0344] Air: In certain forms of the present technology, air may refer to atmospheric air, while in other forms of the present technology, air may refer to combinations of other breathable gases (e.g., oxygen-rich atmospheric air).

[0345] Atmosphere: In certain forms of the present technology, the term "atmosphere" should be taken to mean: (i) that which is external to the treatment system or patient, and (ii) that which immediately surrounds the treatment system or patient.

[0346] For example, the ambient humidity for a humidifier may be the humidity of the air immediately surrounding the humidifier (e.g., the humidity inside the room in which the patient sleeps). Such ambient humidity may differ from the humidity outside the room in which the patient sleeps.

[0347] In another example, the atmospheric pressure may be the pressure immediately surrounding or external to the body.

[0348] In certain embodiments, ambient (e.g., acoustic) noise can be considered the background noise level in the room the patient is in, other than noise emanating from, for example, the RPT device or from the mask or patient interface. Ambient noise can originate from sources outside the room.

[0349] Automatic Positive Airway Pressure (APAP) Therapy: A CPAP therapy that is capable of automatically adjusting therapeutic pressure between minimum and maximum limits, for example, between breaths, depending on the presence or absence of signs of an SDB episode.

[0350] Continuous Positive Airway Pressure (CPAP) Therapy: Respiratory pressure therapy in which the therapeutic pressure is approximately constant throughout the patient's respiratory cycle. In some forms, the pressure at the entrance to the airway increases slightly during expiration and decreases slightly during inspiration. In some forms, the pressure varies during different respiratory cycles of the patient (e.g., increased in response to detection of an indication of partial upper airway obstruction and decreased in the absence of notification of partial upper airway obstruction).

[0351] Flow Rate: The instantaneous amount (or mass) of air delivered per unit time. Flow rate may refer to an instantaneous quantity. In some cases, when referring to flow rate, it refers to a scalar quantity (i.e., a quantity that has only magnitude). In other cases, when referring to flow rate, it refers to a vector quantity (i.e., a quantity that has both magnitude and direction). Flow rate may be given the symbol Q. "Flow rate" may also be called "flow" for short.

[0352] In the example of a patient's breath, the flow rate may be nominally positive for the inhalation portion of the patient's breathing cycle, and therefore negative for the exhalation portion of the patient's breathing cycle. Total flow rate Qt is the flow rate of air exiting the RPT device. Ventilator flow rate Qv is the flow rate of air exiting the vent to allow for the outflow of exhaled gases. Leakage flow rate Ql is the flow rate of leakage from the patient interface system or elsewhere. Respiratory flow rate Qr is the flow rate of air received into the patient's respiratory system.

[0353] Humidifier: The word "humidifier" is to be construed as meaning a humidification device constructed, arranged or configured with a physical structure capable of providing a therapeutically beneficial quantity of water (H20) vapor to an air stream to improve the medical respiratory condition of a patient.

[0354] Leakage: The term "leakage" is taken as an unintended air flow. In one embodiment, a leak may occur due to an imperfect seal between the mask and the patient's face. In another embodiment, a leak may occur at the elbow to the perimeter.

[0355] Noise Conduction (Acoustic): In this document, conducted noise refers to noise that is carried to the patient by the pneumatic path (e.g., the air circuit and the patient interface and the air therein). In one form, conducted noise can be quantified by measuring the sound pressure level at the end of the air circuit.

[0356] Noise Emission (Acoustic): In this document, radiated noise refers to noise that is carried by the surrounding air to the patient. In one form, radiated noise can be quantified by measuring the sound power / pressure level of the target according to ISO 3744.

[0357] Ventilation Noise (Acoustic): In this document, ventilation noise refers to the noise generated by airflow through any vents (eg, vent holes in the patient interface).

[0358] Patient: A person with or without respiratory disease.

[0359] Pressure: Force per unit area. Pressure can be expressed and measured in a variety of units (e.g., cmH2O, gf / cm 2 , and hectopascals). 1cmH2O is 1g-f / cm 2 which is approximately 0.98 hectopascals. In this specification, pressure is given in units of cmH2O unless otherwise specified.

[0360] The pressure in the patient interface is given the symbol Pm, and the therapeutic pressure, which represents the target value that the mask pressure Pm should achieve at this moment, is given the symbol Pt.

[0361] Respiratory Pressure Therapy (RPT): The application to the airway inlet of an air supply at therapeutic pressure, typically a positive pressure relative to the atmosphere.

[0362] Ventilator: A mechanical device that provides pressure support to a patient during some or all of the work of breathing.

[0363] 5.7.1.1 Materials

[0364] Silicone or Silicone Elastomer: Synthetic rubber. In this specification, when silicone is mentioned, it refers to liquid silicone rubber (LSR) or compression molded silicone rubber (CMSR). One form of commercially available LSR is SILASTIC (in a family of products sold under this trademark) manufactured by Dow Corning. Another LSR manufacturer is Wacker. Unless otherwise specified to the contrary, exemplary forms of LSR have a Shore A (or Type A) indentation hardness of about 35 to about 45 as measured by ASTM D2240.

[0365] Polycarbonate: A thermoplastic polymer of bisphenol A carbonate.

[0366] 5.7.1.2 Mechanical properties

[0367] Elasticity: The ability of a material to absorb energy during elastic deformation and to release the energy when unloaded.

[0368] Elastic: Releases substantially all of the energy upon unloading. Examples include certain silicone and thermoplastic elastomers.

[0369] Hardness: The ability of a material to resist deformation within itself (as described, for example, by Young's Modulus or the indentation hardness scale measured over a standardized sample size). "Soft" materials may include silicone or thermoplastic elastomers (TPEs) and may easily deform under finger pressure, for example. "Hard" materials may include polycarbonate, polypropylene, steel or aluminum, and do not easily deform under finger pressure, for example.

[0370] Stiffness (or rigidity) of a structure or component: The ability of a structure or component to resist deformation when subjected to a load. The load can be a force or a moment (e.g., compression, extension, bending, or torsion). A structure or component may offer different resistance in different directions.

[0371] Floppy Structure or Component: A structure or component that changes shape (e.g., flexes) within a relatively short period of time (e.g., 1 second) when forced to support its own weight.

[0372] Rigid Structure or Component: A structure or component that does not substantially change shape when subjected to loads typically encountered in use. An example of such an application may be setting up and maintaining a patient interface in a sealed manner against a patient airway entrance under a pressure load of, for example, approximately 20-30 cmH2O.

[0373] As one example, an I-beam may include a different bending stiffness (resistance to bending load) in a first direction compared to a second, orthogonal direction, hi another example, a structure or component may be floppy in a first direction and stiff in a second direction.

[0374] 5.7.2 Breathing cycle

[0375] Apnea: According to some definitions, apnea is said to occur when flow below a certain threshold continues for a duration of, for example, 10 seconds. Obstructive apnea is said to occur when some airway obstruction does not allow airflow despite patient effort. Central apnea is said to refer to a condition in which apnea is detected due to reduced or absent respiratory effort despite a patent airway. Mixed apnea is said to refer to a condition in which reduced or absent respiratory effort occurs simultaneously with airway obstruction.

[0376] Respiratory Rate: The patient's spontaneous breathing rate, usually measured in breaths per minute.

[0377] Duty Cycle: The ratio of inspiration time Ti to total breathing time Ttot.

[0378] Effort (Respiration): Respiratory effort is said to refer to the movement made by a person's spontaneous breathing in an attempt to breathe.

[0379] Expiratory portion of the respiratory cycle: the period from the start of the expiratory flow to the start of the inspiratory flow.

[0380] Flow limitation: Flow limitation is understood to be a situation in a patient's breathing where an increase in effort by the patient does not cause a corresponding increase in flow. If the flow limitation occurs during the inhalation portion of the respiratory cycle, the flow limitation may be referred to as inhalation flow limitation. If the flow limitation occurs during the exhalation portion of the respiratory cycle, the flow limitation may be referred to as expiratory flow limitation.

[0381] Flow-limited inspiration waveform types: (i) Flattening: An upswing followed by a relatively flat area and then a downswing. (ii) M-shaped: It has two local peaks, one at the rise and one at the fall, with a relatively flat region between the two peaks. (iii) Chair-like: Has a single local peak that occurs at the rising edge and is followed by a relatively flat region. (iv) Inverted chair shape: A relatively flat region is followed by a single local peak, which occurs on the trailing edge.

[0382] Hypopnea: By some definitions, hypopnea refers to a reduction in flow, rather than an interruption of flow. In one form, hypopnea is said to occur when there is a sustained period of reduced flow below a threshold rate. When hypopnea is detected due to a reduction in respiratory effort, central hypopnea is said to occur. In one form in adults, hypopnea may be considered when any of the following occur: (i) A 30% decrease in patient respiration for at least 10 seconds plus an associated 4% desaturation, or (ii) A reduction in patient respiration (less than 50%) lasting for at least 10 seconds and associated with at least 3% desaturation or arousal occurs.

[0383] Hyperventilation: An increase in flow to a level higher than normal.

[0384] Inspiration portion of the respiratory cycle: The period from the start of the inspiratory flow to the start of the expiratory flow is taken as the inspiration portion of the respiratory cycle.

[0385] Patency (Airway): The degree to which the airway is open or the extent to which the airway is open. Airway patency is an opening. Airway patency may be quantified, for example, with a value of 1 indicating open and a value of 0 indicating closed (obstructed).

[0386] Positive end-expiratory pressure (PEEP): The pressure above atmosphere in the lungs that exists at the end of expiration.

[0387] Peak flow (Qpeak): The maximum value of flow during the inspiratory portion of the respiratory flow waveform.

[0388] Respiratory airflow, airflow, patient airflow, respiratory airflow (Qr): these terms may be understood to refer to the RPT device's estimate of respiratory airflow and are used in contrast to "true respiratory flow" or "true respiratory airflow", which is the patient's actual respiratory flow, usually expressed in liters / minute.

[0389] Tidal Volume (Vt): The volume of air inhaled or exhaled during normal breathing without extra effort.

[0390] (Inspiration) Time (Ti): The duration of the inspiratory portion of the respiratory flow waveform.

[0391] (Expiratory) Time (Te): The duration of the expiratory portion of the respiratory flow waveform.

[0392] (Total) Time (Ttot): The total duration between the start of one inspiratory portion of the respiratory flow waveform and the start of the next inspiratory portion of the respiratory flow waveform.

[0393] Typical Recent Ventilation: The ventilation value around which the most recent values ​​of ventilationVent tend to cluster over a given time scale (i.e., the degree to which the most recent values ​​of ventilation tend to be central).

[0394] Upper Airway Obstruction (UAO): Includes both partial and total upper airway obstruction. Can be associated with a state of flow limitation in which flow may increase or decrease slightly with increasing pressure differential across the upper airway (Starling resistor behavior).

[0395] Vent: A measurement of the rate of gas exchange performed by a patient's respiratory system. Measurements of ventilation may include either or both inhaled and exhaled airflow per unit of time. When expressed as volume per minute, this amount is often referred to as "minute ventilation." Minute ventilation is sometimes simply given as volume and is understood as volume per minute.

[0396] 5.7.3 Ventilation

[0397] Adaptive servo-ventilator (ASV): A servo-ventilator that does not have a fixed target ventilation, but rather is variable. The variable target ventilation can be learned from some characteristics of the patient (e.g., the patient's breathing characteristics).

[0398] Backup Rate: A ventilator parameter that establishes the minimum respiratory rate (typically in breaths per minute) that will be delivered from the ventilator to the patient (when not triggered by spontaneous breathing efforts).

[0399] Cycle: The end of the inspiratory phase of a ventilator. When a ventilator delivers breaths to a spontaneously breathing patient, at the end of the inspiratory portion of the breathing cycle, the ventilator is said to be cycled to stop breath delivery.

[0400] Expiratory Positive Airway Pressure (EPAP): The base pressure to which varying pressures are added during a breath to produce the desired mask pressure that the ventilator is attempting to achieve at a given time.

[0401] End Expiratory Pressure (EEP): The desired mask pressure that the ventilator attempts to achieve at the end of the expiratory portion of the breath. If the pressure waveform template Π(Φ) has a value of zero at the end of expiration (i.e., Π(Φ)=0 when Φ=1), then EEP is equal to EPAP.

[0402] Inspiratory Positive Airway Pressure (IPAP): The maximum desired mask pressure that the ventilator attempts to achieve during the inspiratory portion of the breath.

[0403] Pressure Support: A number indicating the increase in pressure during ventilator inhalation followed by exhalation of the same ventilator, and generally refers to the pressure difference between the maximum inhalation pressure and the base pressure (e.g., PS=IPAP-EPAP). In some contexts, pressure support refers to the difference the ventilator tries to achieve (rather than the difference it actually achieves).

[0404] Servo-ventilator: a ventilator that has patient ventilation and has target ventilation, and adjusts the level of pressure support to approximate the patient ventilation to the target ventilation.

[0405] Spontaneous / Timed (S / T): A mode of a ventilator or other device that attempts to detect the onset of a breath in a spontaneously breathing patient. However, if the device fails to detect a breath within a predetermined period of time, the device automatically begins breath delivery.

[0406] Swing: A term equivalent to pressure assistance.

[0407] Triggered: When a ventilator delivers a breath of air to a spontaneously breathing patient, the ventilator is said to be triggered to deliver a breath when the patient himself initiates the breathing portion of the breathing cycle.

[0408] Typical Recent Ventilation: Typical recent ventilation Vtyp is a range of values ​​around which recent ventilation measurements tend to cluster over a given time scale. For example, a measure of the central tendency of ventilation measurements over the recent history may be an appropriate value of typical recent ventilation.

[0409] 5.7.4 Anatomy

[0410] 5.7.4.1 Facial anatomy

[0411] Alar: the outer wall or "wing" of each nostril (plural: alar)

[0412] Alare: The outermost point on the ala of the nose.

[0413] Wing curvature (or apex) point: the rearmost point on the curved baseline of each wing, found at the crease formed by the union of the wing and cheek.

[0414] Pinna: the entire visible part of the ear.

[0415] (Nasal) Skeleton: The nasal skeleton includes the nasal bones, the frontal process of the maxilla, and the nasal part of the frontal bone.

[0416] (Nasal) Cartilaginous folds: The nasal cartilaginous folds include the septal cartilage, lateral cartilage, greater cartilage and lesser cartilage.

[0417] Columella: The piece of skin that separates the nostrils and extends from the tip of the nose to the upper lip.

[0418] Columella angle: the angle between a line drawn through the midpoint of the nostrils and a line drawn perpendicular to the Frankfurt horizontal intersecting the subnasal point.

[0419] Frankfort horizontal plane: A line extending from the inferiormost point of the orbital rim to the left auricular point, which is the deepest point above the notch to the tragus of the pinna.

[0420] Glabellar: Located in the soft tissue, the most prominent point on the midsagittal portion of the forehead.

[0421] Lateral nasal cartilage: a generally triangular plate of cartilage whose upper margin is attached to the nasal bone and the frontal process of the maxilla and whose lower margin is connected to the greater alar cartilage.

[0422] Greater alar cartilage: a plate of cartilage located beneath the lateral nasal cartilage. It curves around the anterior part of the nostril. Its posterior end is attached to the frontal process of the maxilla by a tough fibrous membrane containing three or four alar cartilages.

[0423] Nostrils (alanopsia): roughly ellipsoidal alar openings that form the entrance to the nasal cavity. The singular form of nostril is nostril (alanopsia). The nostrils are separated by the nasal septum.

[0424] Nasolabial fold or nasolabial crease: a fold or groove of skin that runs from each side of the nose to the corners of the mouth and separates the cheeks from the upper lip.

[0425] Nasolabial angle: the angle between the bridge of the nose and the upper lip, intersecting with the subnasal point.

[0426] Inferior tympanic point: lowest point of attachment of the pinna to the facial skin.

[0427] Inferior auricular margin: the highest point of attachment of the pinna to the facial skin.

[0428] Nasal tip: the most prominent point or tip of the nose, which can be seen in a lateral view of the rest of the head section.

[0429] Philtrum: midline groove extending from the lower border of the nasal septum to the top of the lip in the upper lip area.

[0430] Pogonion: The most anterior midpoint of the jaw, located on the soft tissue.

[0431] (Nasal) ridge: The nasal ridge is the midline prominence of the nose, extending from the serion to the apex.

[0432] Sagittal plane: a vertical plane running from anterior (front) to posterior (back) that divides the body into right and left halves.

[0433] Cerion: Located on the soft tissue, it is the most concave point on the area of ​​the frontonasal suture.

[0434] Septal cartilage (nose): The nasal septal cartilage is part of the septum, which divides the anterior part of the nasal cavity.

[0435] Nasal Alar Lowest Point: The point on the lower margin of the alar base where it joins with the skin of the upper (top) lip.

[0436] Subnasal point: located on the soft tissue where the columella joins the upper lip in the midsagittal direction.

[0437] Supramentale: the most concave point in the midline of the lower lip between the lower lip midpoint and the soft tissue pogonion.

[0438] 5.7.4.2 Skull anatomy

[0439] Frontal bone: The frontal bone contains the large vertical portion, the scales frontalis, which correspond to the area known as the forehead.

[0440] Mandible: The mandible forms the lower jaw. The mental eminence is a bony protuberance in the jaw, forming the chin.

[0441] Maxilla: The maxilla forms the upper jaw and is located below the mandible and below the eye socket. The frontal process of the maxilla projects upwards by the side of the nose and forms part of its lateral border.

[0442] Nasal bones: The nasal bones are two small rectangular bones that vary in size and shape from one individual to another. They lie side by side in the middle and upper parts of the face and their junction forms the "bridge" of the nose.

[0443] Nasion: the intersection of the frontal bone and the two nasal bones; it is the concave area directly between the eyes and the upper side of the bridge of the nose.

[0444] Occipital bone: The occipital bone is located at the back and lower part of the skull. It contains an oval hole, the foramen magnum, through which the intracranial cavity communicates with the vertebral canal. The curved plate posterior to the foramen magnum is the squama occipitalis.

[0445] Orbit: bony cavity in the skull that contains the eyeball.

[0446] Parietal bones: The parietal bones are the bones that, when joined together, form the top and sides of the skull.

[0447] Temporal Bone: The temporal bone is located at the base and on the side of the skull and supports parts of the face known as the temples.

[0448] Cheekbones: The two cheekbones in the face are located in the upper and outer parts of the face and form the cheek ridges.

[0449] 5.7.4.3 Respiratory system anatomy

[0450] Diaphragm: A sheet of muscle that runs over the lower rib cage. It separates the thoracic cavity, which contains the heart, lungs, and ribs, from the abdominal cavity. When the diaphragm contracts, it increases the volume of the thoracic cavity and draws air into the lungs.

[0451] Larynx: The larynx or voice box that contains the vocal folds and connects the lower part of the pharynx (hypopharynx) to the trachea.

[0452] Lung: respiratory organ in humans. The conductive zone of the lung includes the trachea, bronchi, bronchiole, and terminal bronchioles. The respiratory zone includes the respiratory bronchioles, alveolar ducts, and alveoli.

[0453] Nasal Cavity: The nasal cavity (or nasal fossa) is a large air-filled space in the center of the face above and behind the nose. The nasal cavity is divided into two by a vertical fin called the nasal septum. On the sides of the nasal cavity are three horizontal extensions called the turbinates or nasal bones. At the front of the nasal cavity is the nose, and at the back it opens into the nasopharynx via the choanae.

[0454] Pharynx: The part of the throat located immediately below (inferior to) the nasal cavity and above the esophagus and larynx. The pharynx is traditionally divided into three parts: the nasopharynx (upper pharynx) (nasal part of the pharynx), the oropharynx (middle pharynx) (oral part of the pharynx), and the hypopharynx (lower pharynx).

[0455] 5.7.5 Patient Interface

[0456] Anti-asphyxiation valve (AAV): A component or subassembly of a mask system that reduces the risk of excessive rebreathing of CO2 by the patient by venting to atmosphere in a fail-safe manner.

[0457] Elbows Elbows are examples of structures that direct the axis of airflow moving therethrough to change direction through an angle. In one form, the angle can be approximately 90 degrees. In another form, the angle can be greater than or less than 90 degrees. The elbow can have a generally circular cross section. In another form, the elbow can have an oval or rectangular cross section. In certain forms, the elbow can be rotatable, for example, about 360 degrees, relative to the mating component. In certain forms, the elbow can be removable from the mating component, for example, via a snap connection. In certain forms, the elbow can be assembled to the mating component via a one-time snap at the time of manufacture, but cannot be removed by the patient.

[0458] Frame: Frame is taken to mean a mask structure that supports a tensile load between two or more points that connect the headgear. A mask frame may be a non-airtight load-bearing structure in the mask. However, some forms of mask frames may be airtight.

[0459] Headgear: Headgear is taken to mean a form of positioning and stabilizing structure designed to be used on the head. For example, the headgear may include a collection of one or more posts, ties and stiffeners configured to position and hold the patient interface in place on the patient's face for delivery of respiratory therapy. Some ties are formed from a soft, flexible, elastic material (e.g., a layered composite of foam and fabric).

[0460] Membrane: Membrane is taken to mean a typically thin-walled element, preferably offering substantially no resistance to bending and resistance to stretching.

[0461] Plenum Chamber: Mask plenum chamber is taken to mean a part of a patient interface having a wall that at least partially encloses a volume of space, the air in the volume being pressurized to exceed atmospheric pressure in use. The shell may form part of the wall of the mask plenum chamber.

[0462] Seal: When used as a noun ("seal") it can refer to a structure, and when used as a verb ("seal") it can refer to an effect. Two elements can be constructed and / or arranged to "seal" or achieve a "sealing" effect between them without the need for a separate "sealing" element itself.

[0463] Shell: A shell is taken to mean a curved, relatively thin structure that has bending, tensile and compressive stiffness. For example, the curved structural wall of a mask may be a shell. In some forms, the shell may be faceted. In some forms, the shell may be airtight. In some forms, the shell may not be airtight.

[0464] Stiffener: A stiffener is taken to mean a structural component designed to increase the bending stiffness of another component in at least one direction.

[0465] Strut: A strut is taken to mean a structural component designed to increase the compressive resistance of another component in at least one direction.

[0466] Swivel (noun) A subassembly of components configured to rotate, preferably independently, about a common axis, preferably under low torque. In one form, the swivel may be configured to rotate through an angle of at least 360 degrees. In another form, the swivel may be configured to rotate through an angle of less than 360 degrees. When used in the context of an air delivery conduit, the subassembly of components preferably includes a mating cylindrical conduit. In use, there is little or no air leakage from the swivel.

[0467] Tie (noun): A structure designed to resist tension.

[0468] Venting: (noun): A structure that allows airflow to the ambient air inside a mask or conduit, allowing clinically effective flushing of exhaled gases. For example, flow rates of about 10 liters / minute to about 100 liters / minute may be used for clinically effective flushing, depending on mask design and treatment pressure.

[0469] 5.7.6 Shape of structure

[0470] A product of the present technology may include one or more three-dimensional mechanical structures (e.g., a mask cushion or impeller). The three-dimensional structures may be bounded by two-dimensional surfaces. These surfaces may be differentiated with labels to describe the orientation, location, function, or some other characteristic of the associated surfaces. For example, the structure may include one or more of a front surface, a back surface, an inner surface, and an outer surface. In another example, the cushion structure may include a face-containing (e.g., outer) surface and a separate face-free (e.g., lower or inner) surface. In another example, the structure may include a first surface and a second surface.

[0471] To facilitate the description of the shape and surface of a three-dimensional structure, a cross section at a point p through the surface of the structure is first considered. See Figures 3B-3F. Figures 3B-3F show an example cross section at a point p on the surface, and an example of the resulting planar curve. Figures 3B-3F also show the outward normal vector at p. The outward normal vector at p points away from the surface. In some examples, the surface is described from the perspective of a fictional little person standing upright on the surface.

[0472] 5.7.6.1 Curvature in one dimension

[0473] The curvature of a plane curve at p can be described as having a sign (eg, positive, negative) and a magnitude (eg, 1 / radius of the circle tangent to the curve at p).

[0474] Positive curvature: If the curve at p bends towards the outward normal, the curvature at that point is taken to have a positive value (if this imaginary little person walks away from point p, he or she would have to walk uphill). See Figure 3B (relatively large positive curvature compared to Figure 3C) and Figure 3C (relatively small positive curvature compared to Figure 3B). Such curves are often called concave.

[0475] Zero curvature: If the curve at p is a straight line, the curvature is taken as zero (if this imaginary little person walks away from point p, he can walk on a horizontal plane that is neither pointing up nor down). See Figure 3D.

[0476] Negative curvature: If the curve at p bends away from the outward normal, the curvature at that point and in that direction is taken to have a negative value (if this imaginary little person were to walk away from point p, he would have to walk downhill). See Figure 3E (relatively small negative curvature compared to Figure 3F) and Figure 3F (relatively large negative curvature compared to Figure 3E). Such curves are often called convex.

[0477] 5.7.6.2 Two-dimensional surface curvature

[0478] The description of a shape at a given point on a two-dimensional surface according to the present technology may include multiple perpendicular cross sections. The multiple cross sections may cut the surface in a plane that includes the outward normal (the "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 the point may have the same sign or different signs. Each of the curvatures at the point has a (e.g., relatively small) magnitude. The plane curves in Figures 3B-3F may be examples of such multiple cross sections at a particular point.

[0479] Principal curvature and direction: The directions of the normal plane in which the curvature of the curve has a maximum and a minimum value are called the principal directions. In the example of Figures 3B-3F, the maximum curvature occurs in Figure 3B and the minimum occurs in Figure 3F, so Figures 3B and 3F are cross sections in the principal directions. The principal curvature at p is the curvature in the principal direction.

[0480] Surface region: A collection of connected points on a surface. This set of points within a region may have similar properties (e.g., curvature or sign).

[0481] Saddle Region: A region where the principal curvatures at each point have opposite signs (i.e., one positive sign and the other negative sign) (depending on the direction a hypothetical person who may be walking uphill or downhill is facing).

[0482] Dome Area: A region where the principal curvatures at every point have the same sign: both positive ("concave dome") or both negative ("convex dome").

[0483] Cylindrical domain: A domain in which one principal curvature is zero (or, for example, zero within manufacturing tolerances) and the other principal curvature is non-zero.

[0484] Planar Region: Region of a surface where both principal curvatures are zero (or are zero within a manufacturing tolerance, for example).

[0485] Surface Edge: the boundary or limit of a surface or area.

[0486] Path: In certain forms of the technology, a "path" is taken to mean a path in the mathematical-topological sense (e.g., a continuous space curve from f(0) to f(1) on a surface). In certain forms of the technology, a "path" may be described as a route or course that includes, for example, a set of points on a surface. (A fictional person's path is a place to walk on a surface, similar to a path in a garden.)

[0487] Path Length: In certain forms of the present technology, "path length" is taken to refer to the distance along a surface from f(0) to f(1) (i.e., the distance along a 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 of a fictional person is the distance walked along a path on the surface.)

[0488] Straight-line distance: Straight-line distance is the distance between two points on a surface, but does not take the surface into account. On a planar area, there is a distance on the surface edge that has the same path length as the straight-line distance between two points on the surface. On a non-planar surface, there cannot be a path that has the same path length as the straight-line distance between two points. (For a fictional person, straight-line distance corresponds to the distance "as the crow flies.")

[0489] 5.7.6.3 Space curve

[0490] Space Curve: Unlike a plane curve, a space curve does not necessarily exist in any particular plane. A space curve may be considered a one-dimensional piece of three-dimensional space. A fictional character walking on a strand of DNA helix walks along a space curve. A typical human left ear includes a left-handed helix (see FIG. 3Q). A typical human right ear includes a right-handed helix (see FIG. 3R). FIG. 3S shows a right-handed helix. The edge of a structure (e.g., the edge of a membrane or impeller) may trace a space curve. In general, a space curve may be described by the curvature and twist at each point on the space curve. Twist is a measure of the way the curve emanates from the plane. Twist has a sign and a magnitude. The twist at a point on a space curve may be characterized with respect to the tangent, normal, and binormal vectors at that point.

[0491] Tangent unit vector (or unit tangent vector): For each point on a curve, the vector at that point specifies the direction and magnitude from that point. A tangent unit vector is a unit vector that points in the same direction as the curve at that point. If a fictional character was flying along a curve and fell off his vehicle at a particular point, the direction of the tangent vector is the direction he would be traveling.

[0492] Unit normal vector: If a fictional character is moving along a curve, this tangent vector itself changes. The unit vector that points in the same direction as the tangent vector is changing is called the unit principal normal vector. It is perpendicular to the tangent vector.

[0493] Binormal unit vector: The binormal unit vector is perpendicular to both the tangent vector and the principal normal vector. Its direction can be determined by the right-hand rule (see, for example, Figure 3P) or the left-hand rule (Figure 3O).

[0494] Tangent plane: the plane containing the unit tangent vector and the unit principal normal vector, see Figures 3O and 3P.

[0495] 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 the degree of deviation of the curve from the tangential plane. The torsion of a space curve that lies within the plane is zero. If the space curve deviates from the tangential plane by a relatively small amount, the magnitude of torsion of the space curve is relatively small (e.g., a gently sloping spiral path). If the space curve deviates from the tangential plane by a relatively large amount, the magnitude of torsion of the space curve is relatively large (e.g., a steeply sloping spiral path). With reference to FIG. 3S, the magnitude of torsion of the neighbors of the top coil of the spiral in FIG. 3S is greater than the magnitude of torsion of the bottom coil of the spiral in FIG. 3S because T2>T1.

[0496] Referring to the right-hand rule in Figure 3P, a space curve that bends towards the right-hand binormal can be considered to have a positive twist in the right-hand direction (e.g., a right-hand spiral as shown in Figure 3S). A space curve that bends away from the right-hand binormal can be considered to have a negative twist in the right-hand direction (e.g., a left-hand spiral).

[0497] Similarly, with reference to the left-hand rule (see Figure 3O), a space curve with a left-handed binormal direction can be considered as having a left-handed positive twist (e.g., a left-handed spiral), where a left-handed positive direction thus corresponds to a right-handed negative direction, see Figure 3T.

[0498] 5.7.6.4 Holes

[0499] A surface may have one-dimensional holes (e.g., holes bounded by a plane or space curve). In the case of a thin structure (e.g., a membrane) that contains holes, the structure may be described as having one-dimensional holes. See, for example, how the one-dimensional holes in the surface of the structure shown in Figure 3I are bounded by a plane curve.

[0500] A structure may have a two-dimensional hole (e.g., a hole bounded by a surface). For example, an inflatable tire has a two-dimensional hole bounded by the tire inner surface. In another example, a bladder with a cavity for air or gel may have a two-dimensional hole. See, for example, the cushion in FIG. 3L and the exemplary cross-section of FIG. 3L in FIG. 3M and FIG. 3N, where the inner surface bounding the two-dimensional hole is shown. In yet another example, a conduit may include a one-dimensional hole (e.g., at its inlet or its outlet) and may include a two-dimensional hole bounded by the inner surface of the conduit. See also the two-dimensional hole through the structure shown in FIG. 3K and bounded by a surface as shown.

[0501] 5.8 Other Notes

[0502] 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 reproduction by any person of this patent document or the patent disclosure by facsimile, for purposes of disclosure in the Patent and Trademark Office patent file or records, but reserves all copyright rights thereto for all other purposes.

[0503] Unless otherwise clearly indicated from the context and unless a range of values ​​is provided, it is understood that each intervening value between the upper and lower limits of the range, the unit of the lower limit, and any other stated or intervening value of the stated range is encompassed by the technology. The upper and lower limits of these intervening ranges, which are independently included in the intervening range, are also encompassed by the technology if they specifically exceed the limits in the stated range. If the stated range includes one or both of these limits, then ranges exceeding either or both of these stated limits are also encompassed by the technology.

[0504] Furthermore, when a value or values ​​are embodied herein as part of the present technology, unless otherwise indicated, it is understood that such values ​​may be approximated and may be used to any appropriate significant figures to the extent practical technical practice permits or requires.

[0505] Unless otherwise specified, all technical and scientific terms 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 be used in the practice or testing of this technology, a limited number of exemplary methods and materials are described herein.

[0506] Although particular materials are described as being preferred for use in the construction of components, obvious alternative materials having similar properties may be substituted. Further, unless stated to the contrary, any and all components described herein are understood to be manufacturable and therefore may be manufactured collectively or separately.

[0507] Please note 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.

[0508] All publications mentioned herein are incorporated by reference to disclose and describe the methods and / or materials that are the subject of these publications. Publications mentioned herein are provided solely for their disclosure prior to the filing date of this application. Nothing herein should be construed as an admission that the present technology does not antedate such publications by virtue of prior patents. Furthermore, the dates of publications mentioned may differ from the actual publication dates, which may require independent confirmation.

[0509] The terms "comprises" and "comprising" should be construed as referring to elements, components, or steps in a non-exclusive sense, indicating that a described element, component, or step may be present in, utilized with, or combined with other elements, components, or steps that are not specifically described.

[0510] The headings used in the detailed description are for the convenience of the reader and should not be used to limit the content found in the disclosure or claims as a whole. These headings should not be used in interpreting the scope of the claims or the limitations of the claims.

[0511] Although the technology herein has been described with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the technology. In some cases, terms and symbols may indicate specific details that are not necessary for the practice of the technology. For example, the terms "first" and "second" (and the like) are used, but unless otherwise specified, these terms are not intended to indicate any order, but are used to distinguish separate elements. Furthermore, although the description or illustration of the process steps in the method may be described in an order, such order is not required. Those skilled in the art will recognize that such order can be changed and / or aspects can be performed simultaneously or even synchronously.

[0512] It is therefore to be understood that numerous modifications may be made in the illustrative embodiments and other arrangements may be devised without departing from the spirit and scope of the present technology. [Explanation of symbols]

[0513] 5.9 List of References 1000 patients 1100 Bedmate 3000 Patient Interface 3100 Seal forming structure 3105 Sealed surface 3110 Joint material 3111 Edge 3115 Outer circumference 3120 Tubular Structure 3125 Sealing flap 3130 Thick Part 3135 Thin Part 3140 Hinge structure 3145 Mounting location 3150 Flap 3155 Rib 3160 Flap 3165 Connection Point 3170 angle 3175 area 3175A area 3175B area 3175C area 3175D area 3175E Area 3175F area 3200 Plenum Chamber 3210 Edge 3220 Peripheral edge 3300 Structure 3400 Ventilation 3600 Connection Port 3700 Forehead support 3800 Cushion Assembly 3810 Cushion 3810 Foam cushion 3812 Flexible Support Clip 3814 Second Clip 3816 Mask Shell 4000 RPT Devices 4170 Air Circuit 5000 humidifier 6000 Cushion Assembly 6005 Shell 6010 Seal forming structure 6010A area 6010B area 6010C area 6010D area 6010E area 6010F area 6015 Support structure 6020 Central opening 6025 First end 6030 Second end 6035 Left side 6040 Right side 6045 sagittal plane 6050 line 6055 First Contact 6060 Second Contact 6065 Closed Path 6070 Open Route 6075 flange section 6080 Base 6085 Frame

Claims

1. 1. A cushion assembly for a patient interface for delivering airflow at a continuous positive pressure relative to ambient air pressure in a sealed manner to an entrance to a patient's airways including at least the entrance to the patient's nares, said patient interface having a pressure of approximately 4 cmH2H higher than ambient air pressure during the patient's entire respiratory cycle while the patient is asleep. ２ O~about 30cmH ２ 10. The cushion assembly is configured to maintain a therapeutic pressure in the range of 100 to 1500 and improve sleep disordered breathing, the cushion assembly comprising: an elastomeric seal-forming structure shaped to be bisected by a sagittal plane having tangents to the elastomeric seal-forming structure at upper and lower tangent points; the curvature of the elastomeric seal-forming structure is saddle-shaped within a first saddle region, the first saddle region straddling the sagittal plane and including an upper tangent point; the curvature of the elastomeric seal-forming structure is dome-shaped within a first dome region and offset from the sagittal plane; the curvature of the elastomeric seal-forming structure transitions in a first transition region from the saddle shape in the first saddle region to the dome shape in the first dome region; the first transition region is between the first saddle region and the first dome region; the curvature of the elastomeric seal-forming structure is cylindrical in the first transition region; an elastomeric wall thickness of the elastomeric seal-forming structure is greater in the first transition region than in the first saddle region and the first dome region; The elastomeric seal-forming structure defines a front central opening in front of the cushion assembly.

2. The cushion assembly of claim 1 , wherein the elastomeric wall thickness in the first transition region increases in a direction away from the front central opening.

3. The cushion assembly of any one of claims 1 to 2, wherein the elastomeric wall thickness in the first dome region increases in a direction away from the front central opening.

4. 4. The cushion assembly of claim 1, wherein the curvature of the elastomeric seal-forming structure is saddle-shaped in a second saddle region, the second saddle region straddling the sagittal plane and including the lower contact point.

5. A cushion assembly as described in claim 4, wherein the second saddle region is configured to contact the patient's upper lip when in use.

6. The cushion assembly of any one of claims 4 to 5, wherein the first saddle region and the second saddle region have the same elastomeric wall thickness.

7. The cushion assembly of any one of claims 4 to 6, wherein the elastomeric wall thickness of the elastomeric seal-forming structure is consistent within a membrane region of the elastomeric seal-forming structure extending from the second saddle region to the first saddle region.

8. 8. The cushion assembly of claim 4, wherein the curvature of the elastomeric seal-forming structure is dome-shaped in a second dome region, the second dome region being located below the first dome region and between the second saddle region and the first dome region.

9. The cushion assembly of claim 8 , wherein the curvature of the elastomeric seal-forming structure is cylindrical in a second transition region connecting the second dome region to the first dome region.

10. 10. The cushion assembly of claim 9, wherein an elastomeric wall thickness in the second transition region and the second dome region is greater than an elastomeric wall thickness in the first saddle region and the second saddle region.

11. The cushion assembly of any one of claims 9 to 10, wherein the cushion assembly in the first dome region and the second transition region loops back onto itself.

12. 1. A patient interface, comprising: A cushion assembly according to any one of claims 1 to 11; a rigid shell removably connected to the cushion assembly; and headgear removably attached to the rigid shell.

13. 1. A CPAP system comprising: A patient interface according to claim 12; a flow generator configured to pressurize the gas flow; an air delivery conduit configured to deliver the pressurized gas to the patient interface.

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