Gas washout vent for patient interface

Abstract

A gas washout vent includes a housing having a first wall with one or more passages through the wall, the passages configured to be in fluid communication with a portion of a patient interface system exposed to therapeutic pressure. The passages include respective first openings on a first surface of the first wall. The housing at least partially defines a second opening in communication with ambient atmosphere. A diffusing material is at least partially located within the housing to be adjacent the first surface. A surface of the diffusing material facing the first surface is spaced apart from the first surface by a gap that extends to provide fluid communication between all of the first openings and between all of the first openings and the second opening. The housing is configured such that air is prevented from flowing out of the housing at all areas directly opposite each of the first openings.

Description

[0001] This application is a divisional application of patent application number 201780079694.4, filed on November 9, 2017, entitled "Gas washout vent for patient interface".

[0002] This application claims the benefit of U.S. provisional application number 62 / 420,678 filed on November 11, 2016, the contents of which are incorporated by reference herein in its entirety. 1BACKGROUND 1.1TECHNICAL 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 apparatuses, and their use.

[0005] 1.2DESCRIPTION OF RELATED ART

[0006] 1.2.1The human respiratory system and its disorders

[0007] The respiratory system of the body facilitates gas exchange. The nose and mouth form the entrance to the airways of the patient.

[0008] The airways include a sequence of branching air tubes, which become narrower, shorter and more numerous as they penetrate more deeply into the lung. The main function of the lung is gas exchange, allowing oxygen to enter and carbon dioxide to leave the venous blood. The trachea divides to form the left and right bronchial tubes, which in turn divide further to form the bronchioles. The bronchi are conductive airways, but do not participate in gas exchange. Other branches of the airways lead to the respiratory bronchioles and ultimately the pulmonary alveoli. The pulmonary alveoli region of the lung is where gas exchange occurs and is known as the respiratory zone. See West, John B. Respiratory Physiology, 9thedition, Lippincott Williams & Wilkins, 2012.

[0009] There is a range of respiratory disorders. Certain disorders can be characterised by particular events, such as apneas, hypopneas, and hyperpneas.

[0010] Examples of respiratory disorders include obstructive sleep apnea (OSA), Cheyne-Stokes Respiration (CSR), hypoxia, obesity hypoventilation syndrome (OHS), chronic obstructive pulmonary disease (COPD), neuromuscular disease (NMD), and chest wall disorders.

[0011] Obstructive Sleep Apnea (OSA) is a form of Sleep Disordered Breathing (SDB) that involves partial or complete obstruction of the upper airway. This form of SDB is characterized by abnormalities in the neuromuscular control of the upper airway. The condition results in repetitive episodes of complete or partial obstruction of the upper airway during sleep. The obstruction causes an absence of breathing (apnea) or a significant reduction in breathing (hypopnea). The condition is a common disorder that often, but not always, goes unrecognized or untreated. See U.S. Patent No. 4,944,310 (Sullivan).

[0012] Cheyne-Stokes Respiration (CSR) is another form of Sleep Disordered Breathing. CSR is a disorder of central origin in which there is a periodic rhythm of increasing and decreasing ventilation. CSR is characterized by a washing-in and washing-out of breath-by-breath fluctuations in ventilation. The CSR cycle typically ends either in hypopneas or apneas. CSR is distinct from OSA in that the repetitive decrease in ventilation is central in origin rather than obstructive. See U.S. Patent No. 6,532,959 (Berthon-Jones).

[0013] Respiratory failure is an encompassing term for disorders of breathing in which the lungs are unable to take in sufficient oxygen or expel sufficient CO2 to meet the needs of the patient. Respiratory failure can include some or all of the following disorders.

[0014] A patient with respiratory insufficiency, a form of respiratory failure, can experience abnormally shortness of breath on exercise.

[0015] Obesity Hyperventilation Syndrome (OHS) is defined as the combination of severe obesity and chronic hypercapnia in the absence of other known causes of hyperventilation. 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 have certain characteristics in common. These include increased resistance to air movement, prolonged expiratory phase, and loss of the normal elasticity of the lung. Examples of COPD are emphysema and chronic bronchitis. COPD is caused by chronic tobacco smoking (the single most important risk factor), occupational exposures, air pollution, and genetic factors. Symptoms include: dyspnea on exertion, chronic cough, and sputum production.

[0017] Neuromuscular Disease (NMD) is a broad term that encompasses many diseases and disorders affecting the muscles and nervous system. Some NMD patients can present with progressive muscular impairment, leading to loss of ambulation, being wheelchair-bound, swallowing difficulties, respiratory muscle weakness, and eventually death from respiratory failure. Neuromuscular disorders can be divided into rapidly progressive and slowly progressive: (i) Rapidly progressive disorders: Characterized by muscle impairment that progresses over months and results in death within a few years (e.g., Amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers). (ii) Variable or slowly progressive disorders: Characterized by muscle impairment that worsens over years and only modestly shortens life expectancy (e.g., Limb girdle, Facioscapulohumeral, and Myotonic muscular dystrophy). Symptoms of respiratory failure in NMD include: increasing general muscle weakness, dysphagia, dyspnea on exertion and at rest, fatigue, sleepiness, morning headache, and difficulties with concentration and mood changes.

[0018] Chest wall disorders are a group of conditions that cause inefficient coupling between the respiratory muscles and the thoracic cage. The disorders often share restrictive defects and the potential to cause chronic hypercapnic respiratory failure. Scoliosis and / or kyphoscoliosis can cause severe respiratory failure. Symptoms of respiratory failure include: dyspnea on exertion and at rest, peripheral oedema, orthopnea, repeated chest infections, morning headache, fatigue, poor sleep quality, and loss of appetite.

[0019] A range of therapies have been used to treat or alleviate such conditions. In addition, these therapies can be utilised on otherwise healthy individuals in order to prevent respiratory disorders from occurring. However, these therapies have a number of drawbacks.

[0020] 1.2.2 Treatment

[0021] Various therapies such as continuous positive airway pressure (CPAP) therapy, non-invasive ventilation (NIV) and invasive ventilation (IV) have been used to treat one or more of the above respiratory disorders.

[0022] Continuous positive airway pressure (CPAP) therapy has been used to treat obstructive sleep apnea (OSA). The mechanism of action is that continuous positive airway pressure acts as a pneumatic splint and can prevent upper airway occlusion by pushing the soft palate and tongue forward and away from the posterior oropharyngeal wall. Treatment of OSA by CPAP therapy can be voluntary, and thus patients can elect not to comply with therapy if they find the device used to provide such therapy: uncomfortable, difficult to use, expensive, and unattractive for any one or more of a number of reasons.

[0023] Non-invasive ventilation (NIV) provides ventilatory support to a patient through the upper airways to assist the patient's breathing and / or to maintain adequate oxygen levels in the body by doing some or all of the work of breathing. The ventilatory support is provided via a non-invasive patient interface. NIV has been used to treat CSR and respiratory failure, which takes the form of conditions such as OHS, COPD, NMD and Chest Wall disorders. In some forms, the comfort and effectiveness of these therapies can be improved.

[0024] Invasive ventilation (IV) provides ventilatory support to a patient who is unable to breathe effectively on their own, and can be provided using an tracheostomy tube. In some forms, the comfort and effectiveness of these therapies can be improved.

[0025] 1.2.3 Therapy system

[0026] These therapies can be provided by a therapy system or device. Such systems and devices can also be used to diagnose a disorder without treating the disorder.

[0027] A therapy system can include a respiratory pressure therapy device (RPT device), an air circuit, a humidifier, a patient interface, and data management.

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

[0029] 1.2.3.1 Patient interface

[0030] A patient interface can be used to interface a respiratory treatment device to its wearer, such as by providing a flow of air to the entrance of the airways. The flow of air can be provided via a mask to the nose and / or mouth of a patient, via a tube to the mouth, or via a tracheal tube to the trachea of a patient. Depending on the treatment to be applied, the patient interface can form a seal with the region around, for example, the patient's face, to facilitate the delivery of gas pressure at a sufficiently different level to ambient pressure to effect therapy, such as positive pressure of about 10 cmH20 relative to ambient pressure. For other forms of therapy, such as the delivery of oxygen, the patient interface can not include a seal sufficient to deliver gas pressure about 10 cmH20 above ambient pressure to the airways.

[0031] Certain other mask systems can not be functionally suitable for the art. For example, masks that are purely decorative can not be able to maintain a suitable pressure. Masks used for swimming or diving underwater can be configured to prevent water from flowing in from the outside at high pressure, rather than to maintain air at a higher pressure than ambient inside.

[0032] Certain masks can be clinically disadvantageous to the art, such as where they block airflow via the nose and only allow it past the mouth.

[0033] Certain masks can be uncomfortable or unachievable for the art if they require the patient to insert a portion of the mask structure into their mouth to form and maintain a seal past their lips.

[0034] Certain masks can be unachievable for use while sleeping, such as when lying on one's side in bed with one's head on a pillow.

[0035] The design of patient interfaces presents several challenges. The face has a complex three-dimensional shape. The size and shape of the nose and head varies significantly from person to person. As the head includes bone, cartilage, and soft tissue, different regions of the face react differently to mechanical forces. The mandible, or lower jaw, can move relative to other bones of the skull. The entire head can move over the course of a respiratory therapy session.

[0036] Due to these challenges, some masks face one or more of the following problems: protrusion, unattractiveness, expense, disproportion, difficulty of use, and discomfort, particularly when worn for a long period of time or when the patient is not familiar with the system. Masks that are incorrectly sized result in reduced compliance, reduced comfort, and poorer patient outcomes. Masks designed only for pilots, masks designed to be part of personal protection equipment, such as filtering masks, SCUBA masks, or masks designed for the administration of anaesthetics, can be acceptable for their original purpose, but are not ideally comfortable for long periods of wear, such as hours. This discomfort can result in reduced patient compliance with therapy. This is particularly true if the mask is worn during sleep.

[0037] CPAP therapy is very effective for treating certain respiratory disorders, assuming patient compliance. If the mask is uncomfortable or difficult to use, the patient can not comply with therapy. Since it is typically recommended that patients clean their masks on a regular basis, if the mask is difficult to clean (e.g., difficult to assemble or disassemble), the patient can not clean their mask, which can impact patient compliance.

[0038] While masks for other applications (e.g., pilots) can not be suitable for treating sleep disordered breathing, masks designed for treating sleep disordered breathing can be suitable for other applications.

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

[0040] 1.2.3.1.1 Seal-forming structure

[0041] A patient interface can include a seal-forming structure. Because of its direct contact with the patient’s face, the shape and configuration of the seal-forming structure can directly impact the effectiveness and comfort of the patient interface.

[0042] A patient interface is characterized, in part, by the design intent of the seal-forming structure in use to interface with the face. In one form of patient interface, the seal-forming structure can include a first sub-portion to form a seal around the left nare and a second sub-portion to form a seal around the right nare. In one form of patient interface, the seal-forming structure can include a single element that surrounds both nare in use. Such a single element can be designed to cover, for example, the upper lip region and the bridge of the nose region of the face. In one form of patient interface, the seal-forming structure can include an element that surrounds the mouth region in use, for example, by forming a seal on the lower lip region of the face. In one form of patient interface, the seal-forming structure can include a single element that surrounds both nare and the mouth region in use. These different types of patient interfaces can be given various names by their manufacturers, including nasal masks, full-face masks, nasal pillows, nasal puffs, and mouth-nose masks.

[0043] A seal-forming structure that can be effective in one region of a patient’s face can not be suitable in another region, for example, because of different shapes, structures, variations, and sensitive areas of a patient’s face. For example, a seal on a swimming goggle that covers a patient’s forehead can not be suitable for use on a patient’s nose.

[0044] Certain seal-forming structures can be designed for mass production, such that one design is suitable, comfortable, and effective for a large range of different face shapes and sizes. To the extent there is a mismatch between the shape of a patient’s face and the seal-forming structure of a mass-produced patient interface, one or both must accommodate to form a seal.

[0045] One type of seal-forming structure extends around the periphery of the patient interface and is used to seal against the patient's face when a force is applied to the patient interface while the seal-forming structure is in facing engagement with the patient's face. The seal-forming structure can comprise an air or fluid-filled cushion, or a molded or formed surface of a resilient seal element made of an elastomer such as rubber. With this type of seal-forming structure, if the fit is not adequate, there will be gaps between the seal-forming structure and the face, and additional force will be required to force the patient interface against the face to achieve a seal.

[0046] Another type of seal-forming structure includes a thin walled piece of material positioned 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. Similar to the previous form of seal-forming structure, if the fit between the face and the mask is not good, additional force can be required to achieve a seal, or the mask can leak. Furthermore, if the shape of the seal-forming structure does not match the shape of the patient, it can wrinkle or buckle in use, leading to leaks.

[0047] Another type of seal-forming structure can include a friction fit element, such as for insertion into the nares, however some patients find these uncomfortable.

[0048] Another form of seal-forming structure can use an adhesive to achieve a seal. Some patients can find it inconvenient to continually apply and remove adhesive to their face.

[0049] A range of patient interface seal-forming structure technologies are disclosed in the following patent applications assigned to ResMed Limited: WO 1998 / 004,310; WO 2006 / 074,513; WO 2010 / 135,785.

[0050] One form of nasal pillow is found in the Adam Circuit, manufactured by Puritan Bennett. Another nasal pillow or nasal prong is the subject of US Patent 4,782,832 (Trimble et al.) assigned to Puritan-Bennett Corporation.

[0051] ResMed Limited has manufactured the following products including nasal pillows: SWIFT® LT TM Nasal pillow mask, SWIFT® LT TM II Nasal pillow mask, SWIFT® LT TM Nasal pillow mask, SWIFT® LT TM Nasal pillow mask, SWIFT® LT TMThe following patent applications assigned to ResMed Limited describe examples of nasal pillow masks: International Patent Application WO 2004 / 073,778 (which describes the ResMed Limited SWIFT® LT nasal TM pillow mask), US Patent Application 2009 / 0044808 (which describes the ResMed Limited SWIFT TM LT nasal pillow mask), International Patent Application WO 2005 / 063,328 and WO 2006 / 130,903 (which describe the ResMed Limited MIRAGE LIBERTY™ full face mask), International Patent Application WO 2009 / 052,560 (which describes the ResMed Limited SWIFT® FX nasal TM pillow mask), International Patent Application WO 2010 / 063,234 (which describes the ResMed Limited ULTRASWIFT™ nasal pillow mask), and International Patent Application WO 201 1 / 100170 (which describes the ResMed Limited ULTRASWIFT™ nasal pillow mask). TM

[0052] 1.2.3.1.2 Positioning and stabilisation

[0053] Seal-forming structures of patient interfaces for positive air pressure therapy are subject to corresponding forces of air pressure to disrupt the seal. Accordingly, various techniques have been used to position the seal-forming structure, and maintain it in a sealing relationship with appropriate portions of the face.

[0054] One technique is to use adhesive. See, for example, US Patent Application Publication No. US 2010 / 0000534. However, the use of adhesive can be uncomfortable for some people.

[0055] Another technique is to use one or more straps and / or stabilising straps. Many such straps suffer from one or more of being ill-fitting, bulky, uncomfortable and difficult to use.

[0056] 1.2.3.2 Respiratory pressure therapy (RPT) devices

[0057] Respiratory pressure therapy (RPT) devices can be used to deliver one or more of the above therapies, such as by generating a flow of air for delivery to an entrance to the airways. The flow of air can be pressurised. Examples of RPT devices include CPAP devices and ventilators.

[0058] Air pressure generators are known in a range of applications, for example industrial scale ventilation systems. However, medical air pressure generators have particular requirements that are not met by more general air pressure generators, for example reliability, size and weight requirements of medical devices. In addition, even devices designed for medical use can have shortcomings with respect to one or more of: comfort, noise, ease of use, efficacy, size, weight, manufacturability, cost and reliability.

[0059] An example of a particular requirement of certain RPT apparatus is noise.​

[0060] Noise output level table for existing RPT devices (only one sample, measured in CPAP mode using the test method specified in ISO 3744 at 10 cmH2O).

[0061] RPT device name A-weighted sound pressure level dB(A) Years (approx.) C Series Tango TM ]] 31.9 2007 C Series Tango with humidifier TM ]] 33.1 2007 [SCS8 Escape TM II]] 30.5 2005 H4i TM S8 Escape TM ]] 31.1 2005 [S9 AutoSet TM ]]> 26.5 2010 S9 AutoSet with H5i humidifier TM ]] 28.6 2010

[0062] One known RPT device for treating sleep-disordered breathing is the ResMed S9 Sleep Therapy System. Another example of an RPT device is a ventilator, such as the ResMed Stellar. TM The series of adult and pediatric ventilation machines can provide invasive and non-invasive, non-dependent ventilation support for a range of patients to treat a variety of conditions, such as, but not limited to, NMD, OHS, and COPD.

[0063] Elisée TM 150 ventilator and ResMed VS III TM Ventilators provide support for invasive and non-invasive dependent ventilation suitable for adult or pediatric patients to treat a variety of conditions. These ventilators offer volumetric and pressure-based ventilation modes with single-channel or dual-channel circuits. RPT devices typically include a pressure generator, such as an electric blower or a compressed gas reservoir, and are configured to supply airflow to the patient's airway. In some cases, airflow to the patient's airway can be supplied under positive pressure. The outlet of the RPT device is connected to a patient interface, such as the one described above, via an air circuit.

[0064] The designer of the device may have provided an almost limitless number of options to make. Design standards often conflict, meaning that some design choices are far from conventional or unavoidable. In addition, certain aspects of comfort and efficiency may be highly sensitive to small and subtle changes in one or more parameters.

[0065] 1.2.3.3 Humidifier

[0066] Delivering an unhumidified airflow can lead to airway dryness. Using a humidifier with an RPT device and patient interface produces humidified gas, minimizing dryness of the nasal mucosa and increasing patient airway comfort. Furthermore, in colder climates, warm air applied to the patient interface and the facial area around the patient interface is generally more comfortable than cold air.

[0067] A range of artificial humidification devices and systems are known, however they may not meet the specific requirements of medical humidifiers.

[0068] Medical humidifiers are used to increase the humidity and / or temperature of an air flow relative to ambient air when required, typically at a location where a patient can be sleeping or resting, such as in a hospital. Medical humidifiers for bedside placement can be small. Medical humidifiers can be configured to humidify and / or heat only the air flow delivered to a patient, without humidifying and / or heating the patient's surroundings. Room-based systems, such as a sauna, air conditioner, or evaporative cooler, for example, can also humidify air for a patient to breathe, however these systems also humidify and / or heat the entire room, which can cause discomfort to the occupants. In addition, medical humidifiers can have more stringent safety limitations than industrial humidifiers.

[0069] While many medical humidifiers are known, they can have one or more shortcomings. Some medical humidifiers can provide inadequate humidification, some can be difficult or inconvenient for a patient to use.

[0070] 1.2.3.4 Vent Technologies

[0071] Some forms of patient interface systems can include a vent to allow flushing of exhaled carbon dioxide. The vent can allow gas to flow from an interior space of the patient interface, such as a plenum chamber, to an exterior space of the patient interface, such as to ambient.

[0072] The vent can include an orifice, and gas can flow through the orifice when the mask is in use. Many such vents are noisy. Others can become obstructed, providing inadequate flushing. Some vents can disrupt the sleep of a bed partner 1100 of the patient 1000, for example, by noise or concentrated gas flow.

[0073] ResMed Limited has developed a number of improved mask vent technologies. See International Patent Application Publication No. WO 1998 / 034,665; International Patent Application Publication No. WO 2000 / 078,381; U.S. Patent No. 6,581,594; U.S. Patent Application Publication No. US 2009 / 0050156; U.S. Patent Application Publication No. US 2009 / 0044808.

[0074] Noise table for existing masks (ISO 17510-2:2007, 10 cm H20 pressure at 1 m)

[0075]

[0076] (* only sample, measured at 10 cm H20 using test method specified in ISO 3744 in CPAP mode)

[0077] Sound pressure values for various objects are shown below

[0078] 2SUMMARY

[0079] The present technology is directed towards providing a medical device for the diagnosis, amelioration, treatment or prevention of a respiratory disorder having one or more of improved comfort, cost, efficacy, ease of use, and manufacturability.

[0080] A first aspect of the present technology relates to apparatus for the diagnosis, amelioration, treatment or prevention of a respiratory disorder.

[0081] A further aspect of the present technology relates to methods for the diagnosis, amelioration, treatment or prevention of a respiratory disorder.

[0082] One aspect of certain forms of the present technology is to provide methods and / or apparatus to improve patient compliance with respiratory therapy.

[0083] One aspect of the present technology includes a gas washout vent for a patient interface system, the gas washout vent comprising: a housing comprising a first wall having one or more passages therethrough, the one or more passages configured to be in fluid communication with a portion of the patient interface system, the portion of the patient interface system configured to be exposed to a therapeutic pressure, the housing at least partially defining a second opening in communication with ambient atmosphere; and a diffusing material at least partially located within the housing.

[0084] One aspect of the present technology includes a gas washout vent for a patient interface system, the gas washout vent configured, in use, to maintain a therapeutic pressure in a range of about 4 cmH20 to about 30 cmH20 above ambient pressure throughout a patient’s respiratory cycle while the patient is sleeping to ameliorate a respiratory or sleep disordered breathing condition, the gas washout vent comprising: a housing comprising a first wall having one or more passages therethrough, the one or more passages configured to be in fluid communication with a portion of the patient interface system, the portion of the patient interface system configured to be exposed to a therapeutic pressure, the passages comprising respective first openings on a first surface of the first wall, the housing at least partially defining a second opening in communication with ambient atmosphere; and a diffusing material at least partially located within the housing to be adjacent the first surface, a surface of the diffusing material facing the first surface being spaced apart from the first surface by a gap, the gap extending to provide fluid communication between all of the first openings and to provide fluid communication between all of the first openings and the second opening; wherein the housing is configured such that air is prevented from flowing out of the housing at all areas directly opposite each of the first openings.

[0085] In examples, (a) the housing further comprises a third opening in communication with the ambient atmosphere, wherein the third opening does not overlap an outlet region of any of the passageways projecting along a central axis of the respective passageway, and is positioned such that the at least partially diffusing material is located between each of the first openings and the third opening; (b) the third opening is oriented such that a central axis through the third opening is at an angle relative to a central axis of any of the passageways; (c) the third opening is sized such that complete occlusion of the third opening does not significantly reduce the flow of gas through the gas washout vent when a portion of the patient interface is exposed to the therapeutic pressure; (d) the flow of gas through the gas washout vent does not reduce by more than three percent; (e) the third opening is one of a number of third openings; (f) the third opening is configured to exclude water; (g) the second opening comprises a number of second openings; (h) at least one of the one or more passageways is sized such that at least a portion of the air exiting the respective first opening penetrates into the diffusing material when a portion of the patient interface is exposed to the therapeutic pressure; (i) the gas washout vent is configured to cause a portion of the air that penetrates into the diffusing material to exit the diffusing material and re-enter the gap prior to flowing out of the second opening; (j) the gas washout vent is configured to cause a portion of the air exiting the respective first opening to penetrate through the surface and exit the diffusing material; (k) the noise generated by the portion of the patient interface being exposed to the therapeutic pressure does not exceed 28 decibels (A) when the air exits the second opening; (l) the diffusing material comprises uncompressed fibres; (m) the diffusing material comprises a moisture absorbing material; (n) the moisture absorbing material is a sintered plastic; (o) the diffusing material comprises a hydrophobic material; (p) the diffusing material has antibacterial properties; (q) the first wall is fixed within the housing in a non-releasable manner; (r) the gap is at least partially defined by the first wall from the first opening to the second opening; (s) the gap is formed by a surface of a portion of the diffusing material from a location opposite the first opening to closest to the second opening; (t) the gap narrows in a radial direction; (u) the gap narrows gradually in a radially outward direction; (v) the surface of the diffusing material is parallel to the first surface; (x) the surface of the diffusing material is inclined to the first surface; (z) a portion of the housing is detachable to allow replacement of the diffusing material; (aa) the second opening and the gap are sized such that a majority of the pressure is dropped in the air before it exits the passageway when the air flows through the passageway, the gap and the second opening; and / or (bb) the gas washout vent comprises a separate device configured to engage with the patient interface or the air circuit.

[0086] Another aspect of the present technology includes a system for treating a respiratory disorder in a patient, the system comprising a respiratory pressure therapy device; a humidifier; an air circuit; and a patient interface, and at least one of the air circuit and the patient interface comprises a gas washout vent according to any preceding aspect or example.

[0087] Of course, portions of aspects can form sub-aspects of the present technology. Additionally, sub-aspects and / or individual aspects within aspects can be combined in any manner and also constitute further aspects or sub-aspects of the present technology.

[0088] Other features of the present technology will be apparent from consideration of the information contained in the following detailed description, abstract, examples and claims. 3 BRIEF DESCRIPTION OF DRAWINGS

[0089] The technology is illustrated in the drawings in which like reference designators

[0090] 3.1 Treatment system

[0091] Figure 1A A system is shown including a patient 1000 wearing a patient interface 3000 as a nasal pillows receives a supply of air at positive pressure from an RPT device 4000. Air from the RPT device 4000 is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000. A bed partner 1100 is also shown. The patient is sleeping in a supine sleeping position.

[0092] Figure 1B A system is shown including a patient 1000 wearing a patient interface 3000 as a nasal mask receives a supply of air at positive pressure from an RPT device 4000. Air from the RPT device is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000.

[0093] Figure 1C A system is shown including a patient 1000 wearing a patient interface 3000 as a full face mask receives a supply of air at positive pressure from an RPT device 4000. Air from the RPT device is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000. The patient is sleeping in a side sleeping position.

[0094] 3.2 Respiratory system and facial anatomy

[0095] Figure 2A A diagrammatic view of the human respiratory system is shown including nasal cavities and oral cavity, larynx, vocal folds, oesophagus, trachea, bronchi, lungs, alveolar sacs, heart and diaphragm.

[0096] Figure 2B A view of the upper airways of a human is shown including nasal cavities, nasal bones, nasal cartilages, greater alar cartilage, nostrils, upper lip, lower lip, larynx, hard palate, soft palate, pharynx, tongue, epiglottic cartilage, vocal folds, oesophagus and trachea.

[0097] Figure 2Cis a front view of a face with several surface anatomical features identified, including the upper lip, upper vermilion, lower vermilion, lower lip, mouth width, endocanthion, nasal ala, nasolabial sulcus, and the corners of the mouth. Superior, inferior, radially inward, and radially outward directions are also indicated.

[0098] Figure 2D is a side view of a head with several surface anatomical features identified, including the glabella, sellion, pronasale, subnasale, upper lip, lower lip, supramenton, nasal ridge, alar crest, otobasion superior, and otobasion inferior. Superior-inferior and anterior-posterior directions are also indicated.

[0099] Figure 2E is another side view of a head. The approximate locations of the Frankfort horizontal and nasolabial angle are indicated. The coronal plane is also indicated.

[0100] Figure 2F shows a bottom view of a nose with several features identified, including the nasolabial sulcus, lower lip, upper vermilion, nostril, subnasale, columella, pronasale, long axis of the nostril, and the sagittal plane.

[0101] Figure 2G shows a side view of the surface features of a nose.

[0102] Figure 2H shows the subdermal structure of a nose, including the lateral cartilages, septal cartilage, greater alar cartilage, lesser alar cartilage, sesamoid cartilage, nasal bone, dermis, adipose tissue, frontal process of the maxilla, and fibrofatty tissue.

[0103] Figure 2I shows the internal anatomy of a nose, about several millimeters medial to the sagittal plane, showing, among other things, the medial crura of the septal cartilage and greater alar cartilages.

[0104] Figure 2J shows a front view of a skull, including the frontal bone, nasal bone, and zygomatic bone. Also indicated are the concha, as well as the maxilla and mandible.

[0105] Figure 2K shows a lateral view of a skull with the surface contours of the head, as well as several muscles. The following bones are shown: frontal, sphenoid, nasal, zygomatic, maxilla, mandible, parietal, temporal, and occipital. The mental protuberance is also indicated. The following muscles are shown: digastric, masseter, sternocleidomastoid, and trapezius.

[0106] Figure 2L shows a front-lateral view of a nose.

[0107] 3.3 Patient interface

[0108] Figure 3A shows a patient interface in the form of a nasal mask in accordance with one form of the present technology.

[0109] Figure 3B A schematic view of a cross-section through the structure at a point is shown. The outward normal at the point is indicated. The curvature at the point has a positive sign and has a relatively large magnitude when compared to the curvature magnitude shown. Figure 3C

[0110] Figure 3C A schematic view of a cross-section through the structure at a point is shown. The outward normal at the point is indicated. The curvature at the point has a positive sign and has a relatively large magnitude when compared to the curvature magnitude shown. Figure 3B

[0111] Figure 3D A schematic view of a cross-section through the structure at a point is shown. The outward normal at the point is indicated. The curvature at the point has a zero value.

[0112] Figure 3E A schematic view of a cross-section through the structure at a point is shown. The outward normal at the point is indicated. The curvature at the point has a negative sign and has a relatively small magnitude when compared to the curvature magnitude shown. Figure 3F

[0113] Figure 3F A schematic view of a cross-section through the structure at a point is shown. The outward normal at the point is indicated. The curvature at the point has a negative sign and has a relatively large magnitude when compared to the curvature magnitude shown. Figure 3E

[0114] Figure 3G A cushion for a mask comprising two pillows is shown. The outer surface of the cushion is indicated. The edge of the surface is indicated. A domed region and a saddle region are indicated.

[0115] Figure 3H A cushion for a mask is shown. The outer surface of the cushion is indicated. The edge of the surface is indicated. A path on the surface between point A and point B is indicated. The straight-line distance between point A and point B is indicated. Two saddle regions and one domed region are indicated.

[0116] Figure 3I A surface of a structure having a one-dimensional hole on it is shown. The planar curve shown forms the boundary of the one-dimensional hole.

[0117] Figure 3J A cross-section through the structure of Figure 3I is shown. The surface shown bounds a two-dimensional hole in the structure of Figure 3I .

[0118] Figure 3K A perspective view of the structure of Figure 3I is shown, the structure comprising a two-dimensional hole and a one-dimensional hole. The surface shown bounds a two-dimensional hole in the structure of Figure 3I ​​​​the surface of the two-dimensional hole in the structure.

[0119] Figure 3L A mask is shown with an inflatable bladder as a bumper.

[0120] Figure 3M A cross-section through Figure 3L a mask is shown, and the interior surface of the bladder is shown. The interior surface bounds the two-dimensional hole in the mask.

[0121] Figure 3N A cross-section through Figure 3L a mask is shown. The interior surface is also indicated.

[0122] Figure 3O The left-hand rule is shown.

[0123] Figure 3P The right-hand rule is shown.

[0124] Figure 3Q The left ear is shown, including the left-ear spiral.

[0125] Figure 3R The right ear is shown, including the right-ear spiral.

[0126] Figure 3S The right-hand spiral is shown.

[0127] Figure 3T A mask view is shown, including the torque sign of a space curve defined by the edges of the sealing film in different regions of the mask.

[0128] 3.4 Breather port

[0129] Figure 4A A breather port according to one form of the technology is shown.

[0130] Figure 4B A breather port according to another form of the technology is shown.

[0131] Figure 4C A breather port according to another form of the technology is shown.

[0132] Figure 4D A breather port according to another form of the technology is shown.

[0133] Figure 4E A breather port according to another form of the technology is shown.

[0134] Figure 4F A breather port according to another form of the technology is shown.

[0135] Figure 4G A breather port according to another form of the technology is shown.

[0136] Figure 4H A vent in a patient interface is shown with its top removed so that the internal structure can be seen. Figure 4G

[0137] Figure 4I A cross-section of a patient interface is shown, but including the top. Figure 4H

[0138] A first alternative cross-section of a patient interface is shown, including additional components. Figure 4J Figure 4H A second alternative cross-section of a patient interface is shown, including additional components.

[0139] 4DETAILED DESCRIPTION Figure 4K Figure 4H Before this technology is described in further detail, it is to be understood that this technology is not limited in scope to the particular examples described herein, which can vary. It is also to be understood that the terminology used in this disclosure is for the purpose of describing the particular examples described herein only and is not intended to be limiting. The following description provides various examples of what can be shared with one or more common characteristics and / or features. It should be understood that one or more features of any one example can be combinable with one or more features of another or other examples. In addition, any single feature or combination of features in any of the examples can constitute further examples.

[0140] 4.1 Treatment

[0141] In one form, the technology comprises 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.

[0142] In certain embodiments of the technology, a supply of air at positive pressure is provided to the nares of a patient via one or both nares.

[0143] In certain embodiments of the technology, mouth breathing is limited, restricted or prevented.

[0144]

[0145] In one form, the technology comprises 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.

[0146] 4.2 Treatment system

[0147] In one form, the technology comprises an apparatus or device for treating a respiratory disorder. The apparatus or device can comprise an RPT device 4000 for supplying pressurized air to a patient 1000 via an air circuit 4170 to a patient interface 3000.

[0148] 4.3 Patient interface

[0149] ​​​The non-invasive patient interface 3000 according to an aspect of the present technology includes the following functional aspects: a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilising structure 3300, a vent 3400, a form of connection port 3600 for connection to a gas circuit 4170, and a forehead support 3700. In some forms, a functional aspect can be provided by one or more physical components. In some forms, one physical component can provide one or more functional aspects. In use, the seal-forming structure 3100 is arranged to surround the entrance to the airways of the patient so as to facilitate the supply of positive pressure air to the airways.

[0150] A patient interface can not be suitable for respiratory pressure therapy if it does not comfortably deliver a minimum level of positive pressure to the airways.

[0151] A patient interface 3000 according to one form of the present technology is constructed and arranged to be capable of providing a supply of air at positive pressure of at least 6 cmH20 relative to ambient.

[0152] A patient interface 3000 according to one form of the present technology is constructed and arranged to be capable of providing a supply of air at positive pressure of at least 10 cmH20 relative to ambient.

[0153] A patient interface 3000 according to one form of the present technology is constructed and arranged to be capable of providing a supply of air at positive pressure of at least 20 cmH20 relative to ambient.

[0154] 4.3.1 Seal-forming structure

[0155] In one form of the present technology, the seal-forming structure 3100 provides a target seal-forming region, and can additionally provide a cushioning function. The target seal-forming region is the region of the seal-forming structure 3100 where a seal is intended to occur. The region where a seal actually occurs - the actual sealing surface - can vary from day to day for a given treatment regime, depending on a range of factors including, for example, the position of the patient interface on the face, the tension of the positioning and stabilising structure, and the shape of the patient's face.

[0156] In one form, the target seal-forming region is located on an external surface of the seal-forming structure 3100.

[0157] In certain forms of the present technology, the seal-forming structure 3100 is constructed from a biocompatible material, such as silicone rubber.

[0158] The seal-forming structure 3100 according to the present technology can be constructed from a soft, pliable and resilient material such as silicone rubber.

[0159] In certain forms of the present technology, a system is provided that includes more than one seal-forming structure 3100, each configured to correspond to a different size and / or shape range. For example, the system can include one form of seal-forming structure 3100 suitable for use with large size heads but not small size heads and another form of seal-forming structure suitable for use with small size heads but not large size heads.

[0160] 4.3.1.1 Sealing mechanism

[0161] In one form, the seal-forming structure includes a sealing flange that uses a pressure-assisted sealing mechanism. In use, the sealing flange can be rapidly responsive to system positive pressure inside the plenum chamber 3200, acting on the underside of the plenum chamber to bring it into sealing engagement with the face. The pressure-assisted mechanism can work in conjunction with the resilient tension in the positioning and stabilising structure.

[0162] In one form, the seal-forming structure 3100 includes a sealing flange and a support flange. The sealing flange includes a relatively thin member having a thickness of less than about 1 mm, for example about 0.25 mm to about 0.45 mm, that extends around the circumference of the plenum chamber 3200. The support flange can be relatively thicker compared to the sealing flange. The support flange is disposed between the sealing flange and the perimeter edge of the plenum chamber 3200 and extends around at least a portion of the perimeter. The support flange is or includes a spring-like element and functions to support the sealing flange from buckling in use.

[0163] In one form, the seal-forming structure can include a compression seal portion or a gasket seal portion. In use, the compression seal portion or gasket seal portion is configured and arranged to be in a compressed state, for example due to the resilient tension in the positioning and stabilising structure.

[0164] In one form, the seal-forming structure includes a tension portion. In use, the tension portion, for example by an adjacent region of the sealing flange, is held in a tensioned state.

[0165] In one form, the seal-forming structure includes a region having a tacky or adhesive surface.

[0166] In certain forms of the present technology, the seal-forming structure can include one or more of a pressure-assisted sealing flange, a compression seal portion, a gasket seal portion, a tension portion, and a portion having a tacky or adhesive surface.

[0167] 4.3.1.2 Nasal bridge or nasal ridge region

[0168] In one form, the non-invasive patient interface 3000 includes a seal-forming structure that forms a seal on the nasal bridge region or the nasal ridge region of the patient's face in use.

[0169] In one form, the seal-forming structure comprises a saddle region configured to form a seal on the nasal bridge region or the nasal ridge region of the patient's face in use.

[0170] 4.3.1.3 Upper lip region

[0171] In one form, the non-invasive patient interface 3000 comprises a seal-forming structure which forms a seal on the upper lip region (i.e. the upper lip) of the patient's face in use.

[0172] In one form, the seal-forming structure comprises a saddle region configured to form a seal on the upper lip region of the patient's face in use.

[0173] 4.3.1.4 Chin region

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

[0175] In one form, the seal-forming structure comprises a saddle region configured to form a seal on the chin region of the patient's face in use.

[0176] 4.3.1.5 Forehead region

[0177] In one form, the seal-forming structure forms a seal on the forehead region of the patient's face in use. In this form, the plenum chamber can cover the eyes in use.

[0178] 4.3.1.6 Nasal pillows

[0179] In one form, the seal-forming structure of the non-invasive patient interface 3000 comprises a pair of nasal puffs or nasal pillows, each constructed and arranged to form a seal with a respective naris of the patient's nose.

[0180] A nasal pillow according to one aspect of the present technology comprises a frusto-conical portion that forms a seal on the underside of the patient's nose, a stem, a flexible region on the underside of the frusto-conical portion and connecting the frusto-conical portion to the stem. In addition, the structure to which the nasal pillow of the present technology is connected comprises a flexible region adjacent the base of the stem. The flexible regions can act in concert to facilitate a universal joint structure that accommodates displacement and angular movement of the frusto-conical portion relative to the structure to which the nasal pillow is connected. For example, the frusto-conical portion can be displaced axially towards the structure to which the stem is connected.

[0181] 4.3.2 Plenum chamber

[0182] In use, the plenum chamber 3200 has a perimeter that is complementary in shape to the surface contours of an average human face. In use, the bounding edges of the plenum chamber 3200 are in close proximity to the adjacent surfaces of the face. Actual contact with the face is provided by the seal-forming structure 3100. The seal-forming structure 3100 can extend around the entire perimeter of the plenum chamber 3200 in use. In certain forms, the plenum chamber 3200 and the seal-forming structure 3100 are composed of a single, uniform material.

[0183] In certain forms of the present technology, the plenum chamber 3200 does not cover the eyes of the patient in use. In other words, the eyes are outside the pressurised volume defined by the plenum chamber. Such forms tend to be less obtrusive and / or more comfortable for the wearer, which can improve compliance with therapy.

[0184] In certain forms of the present technology, the plenum chamber 3200 is constructed from a transparent material (e.g. transparent polycarbonate). The use of a transparent material can reduce the obtrusiveness of the patient interface and help improve compliance with therapy. The use of a transparent material can assist a clinician to observe how the patient interface is positioned and functioning.

[0185] In certain forms of the present technology, the plenum chamber 3200 is constructed from a translucent material. The use of a translucent material can reduce the obtrusiveness of the patient interface and help improve compliance with therapy.

[0186] 4.3.3 Positioning and stabilising structure

[0187] The seal-forming structure 3100 of the patient interface 3000 of the present technology can be held in a sealing position in use by the positioning and stabilising structure 3300.

[0188] In one form, the positioning and stabilising structure 3300 provides a retention force that is at least sufficient to overcome the effect of positive pressure in the plenum chamber 3200 to lift off the face.

[0189] In one form, the positioning and stabilising structure 3300 provides a retention force that is sufficient to overcome the effect of gravity on the patient interface 3000.

[0190] In one form, the positioning and stabilising structure 3300 provides a retention force that is sufficient to overcome the potential effect of disruptive forces (such as from tube drag or incidental interference with use of the patient interface) on the patient interface 3000 as a safety margin.

[0191] In one form of the present technology, a positioning and stabilising structure 3300 is provided that is configured in a manner that is consistent with being worn by a patient while sleeping. In one example, the positioning and stabilising structure 3300 has a small side or cross-sectional thickness to reduce the perceived or actual bulk of the apparatus. In one embodiment, the positioning and stabilising structure 3300 comprises at least one strap that is rectangular in cross-section. In one embodiment, the positioning and stabilising structure 3300 comprises at least one flat strap.

[0192] In one form of the present technology, a positioning and stabilising structure 3300 is provided that is configured to not be too large and bulky to prevent a patient from sleeping in a supine sleeping position with the posterior region of the patient's head on a pillow.

[0193] In one form of the present technology, a positioning and stabilising structure 3300 is provided that is configured to not be too large and bulky to prevent a patient from sleeping in a supine sleeping position with the posterior region of the patient's head on a pillow.

[0194] In one form of the present technology, a positioning and stabilising structure 3300 has a decoupling portion between an anterior portion of the positioning and stabilising structure 3300 and a posterior portion of the positioning and stabilising structure 3300. The decoupling portion does not resist compression and can be, for example, a flexible or floppy strap. The decoupling portion is constructed and arranged so that when the patient's head is lying on a pillow, the presence of the decoupling portion prevents forces at the posterior portion from being transmitted along the positioning and stabilising structure 3300 and disrupting the seal.

[0195] In one form of the present technology, a positioning and stabilising structure 3300 comprises a strap constructed from a laminate of a fabric patient contact layer, a foam inner layer and a fabric outer layer. In one form, the foam is porous to enable moisture (e.g. sweat) to pass through the strap. In one form, the fabric outer layer comprises loop material for partial engagement with hook material.

[0196] In certain forms of the present technology, a positioning and stabilising structure 3300 comprises a strap that is extendable, for example elastically extendable. For example, the strap can be configured in use to bear a tensile force and direct the force to cause the seal-forming structure to be in sealing contact with a portion of the patient's face. In one example, the strap can be configured as a tie.

[0197] In one form of the present technology, a positioning and stabilising structure comprises a first tie configured and arranged so that in use at least a portion of a lower edge thereof passes superiorly to an otobasion superior of the patient's head and covers a portion of the parietal bone without covering the occipital bone.

[0198] In one form of the present technology suitable for use with a nasal mask or a full-face mask, the positioning and stabilising structure includes a second tie, the second tie being constructed and arranged so that at least a portion of its upper edge passes inferiorly to the infra-auricular points of the patient's head and overlies or lies inferior to the patient's occipital bone in use.

[0199] In one form of the present technology suitable for use with a nasal mask or a full-face mask, the positioning and stabilising structure includes a third tie, the third tie being constructed and arranged so that the first tie and the second tie are interconnected to reduce the tendency of the first tie and the second tie to move apart from each other.

[0200] In certain forms of the present technology, the positioning and stabilising structure 3300 includes a strap that is flexible, e.g. non-rigid. An advantage of this aspect is that the strap is more comfortable for the patient to lie on while sleeping.

[0201] In certain forms of the present technology, the positioning and stabilising structure 3300 includes a strap that is constructed to be breathable to allow the transmission of moisture vapour across the strap.

[0202] In certain forms of the present technology, there is provided a system that includes more than one positioning and stabilising structure 3300, each configured to provide a holding force to correspond to a different size and / or shape range. For example, the system can include one form of positioning and stabilising structure 3300 suitable for use with large size heads but not small size heads and another form of positioning and stabilising structure suitable for use with small size heads but not large size heads.

[0203] 4.3.4 Vent

[0204] In one form, the patient interface 3000 includes a vent 3400 constructed and arranged to allow washout of exhaled gases, e.g. carbon dioxide.

[0205] In certain forms, the vent 3400 is configured to allow continuous ventilation from the interior of the plenum chamber 3200 to ambient while the pressure within the plenum chamber is positive relative to ambient. The vent 3400 is configured so that the magnitude of the ventilation flow rate is sufficient to reduce rebreathing of exhaled C02 by the patient while maintaining the therapeutic pressure of the plenum chamber in use.

[0206] The ventilation port 3400 can take various forms. In one form, the ventilation port 3400 according to the present technology includes a plurality of holes, for example, about 20 to about 80 holes, or about 40 to about 60 holes, or about 45 to about 55 holes. The size of each hole can be between 0.5 mm and 1 mm, preferably between 0.6 mm and 0.9 mm, more preferably between 0.7 mm and 0.8 mm. Although the holes are generally formed with circular openings, other shapes are also possible. Some smaller holes can be replaced by one or more larger holes. Some larger holes can be in the form of slits.

[0207] The vent 3400 may be located on or integrated into the inflation chamber 3200 or within the bend 3600. Alternatively, the vent 3400 may be formed separately as a decoupled structure, for example, it may be configured as a pivot of the air circuit 4170 or the portion between the air circuit 4170 and the inflation chamber 3200.

[0208] Figure 4A One implementation of the vent 3400 is shown (e.g., a gas flushing vent). Figure 4A The cross-section shown is a cross-section passing through channel 3402, wall 3404, diffuser material 3406, and housing 3408, each of which surrounds the central airway 3410. Airway 3410 may be part of the inlet of inflation chamber 3200 (e.g., part of a decoupling structure) or may be part of air circuit 4170. The illustrated cross-section includes some symmetry about the central airway 3410, but symmetry is not required.

[0209] The diffuse material 3406 is separated from the wall 3404 by a gap 3412, thereby providing a channel with uninterrupted fluid communication between 3402 and the opening 3416. This is provided by positioning the diffuse material at least partially within the housing, such that the surface 3414 of the diffuse material 3406 faces the surface of the opening 3420. The surface 3414 of the diffuse material is a substantially flat surface and is spaced apart from the surface of the opening 3420 by the gap 3412. This configuration allows the gap to extend to provide fluid communication between all openings 3420 and between all openings 3420 and the opening 3416.

[0210] The opening 3416 provides communication with ambient atmosphere. The size of the gap should be such that any dust that accumulates in the gap can be cleared and any accumulated water will dry out. Thus, the depth of the gap 3412 can be between 1 mm and 3 mm, preferably between 1.5 mm and 2.5 mm, even more preferably about 2 mm. As will be discussed later in this document, this arrangement is such that at least some of the pressurized air (e.g., a jet or pressure wave) exiting the passageway 3402 bridges the gap 3412 and enters the diffusing material 3406 during standard operation of the patient interface. Once the air flow enters the diffusing material, the properties of the material force the air flow to flow to a tortuous path. Even though there is a lower resistance path through the gap 3412, if the air jet, which can be at or near the speed of sound, exerts enough momentum on the air such that at least some of the molecules enter the diffusing material, then air can enter the diffusing material 3406.

[0211] The properties of the diffusing material 3412, such as thickness or density, and the size of the opening 3424 are selected such that the effect of the opening 3424 on the overall air flow is negligible. Also, the second wall 3428 is directly opposite the passageway 3402 with respect to the diffusing material 3406. Thus, the housing 3408 is substantially closed for air flow on the opposite side. As such, the air flow that enters the diffusing material 3406 is forced to eventually return into the gap 3412 and out to ambient air via the opening 3416. The tortuous path imposed on the air flow by the above-described vent configuration greatly reduces the spitting effect and / or the noise produced by the spitting effect associated with the vent. Alternatively or additionally, because the diffusing material 3406 bounds at least one side of the gap 3412, any sound waves that propagate through the gap 3412 are able to expand into the diffusing material 3406 and reduce the sound level, even in the case of little or no net air flow through the diffusing material 3406 itself.

[0212] As shown, the gap 3412 extends all the way along the surface 3414 of the diffusing material 3406 to the opening 3416, but the gap 3412 need not extend along the entire length. For example, there can be no gap at portion 3418 (e.g., the interior of the passageway 3402 closest to the airway 3410, radially inward in the illustrated embodiment). Other configurations of the gap 3412 that provide an uninterrupted path from the passageway 3402 to the passageway 3416 can also be provided.

[0213] With the gap 3412, performance characteristics of the vent 3400 can be improved compared to a vent without a gap. For example, some materials suitable for the diffusing material 3406 can be difficult to manufacture with a consistent density and air permeability. This can result in undesirable variations in washout flow of the vent of different patient interfaces. The introduction of the gap provides a permanent escape path and results in a more consistent and / or predictable washout flow. The gap provides another advantage when air flow through the diffusing material 3406 is reduced or prevented for any reason, such as if the material 3406 has become wet. In this case, the gap 3412 provides an escape path for air to the ambient atmosphere.

[0214] The wall 3404 separates the diffusing material 3406 from the interior of the patient interface 3000 that is exposed to therapeutic pressure during use. The passages 3402 are shown as passing through the wall 3404 and including respective openings 3420 adjacent to and facing the diffusing material 3406. The passages 3402 can be any number and any geometric configuration that provides the desired flow characteristics of the vent 3400. For example, the passages can be cylindrical passages, frustoconical passages, and / or any other three-dimensional shape (such as a slot) that provides the desired performance characteristics of the vent 3400. While in the example shown in FIG. 34, the passages 3402 are shown as being straight, the passages can be curved or otherwise shaped to provide the desired performance characteristics of the vent 3400. Figure 4AIn this particular case, the passage is frustoconical, with a tapering opening downward and toward the diffusing material, although this need not be the case, and the frustoconical tapering opening downward can point in the opposite direction. Any or all of these configurations can provide fluid communication with the interior of the patient interface 3000, which is configured to be exposed to therapeutic pressure. A single passage 3402 or multiple passages can be provided, although providing multiple passages can reduce any audible sound produced. The passage 3402 can be passive or part of a valve system (not shown) that regulates airflow through the passage based on conditions such as therapeutic pressure. The opening 3420 and / or the passage 3402 are sized, and the opening 3420 and diffusing material 3406 are oriented, so that air exiting the opening 3420 can impinge on the diffusing material 3406 at the surface 3414 when the interior of the patient interface 3000 is exposed to therapeutic pressure. Air exiting the opening 3420 can also impinge when the interior is exposed to pressure below therapeutic pressure. With this configuration, at least a portion of the air exiting the opening 3420 can penetrate the diffusing material 3406 when the interior portion of the patient interface 3000 is exposed to therapeutic pressure, then exit from the surface 3414 before exiting the vent via the opening 3416. Any portion of the air that penetrates the diffusing material 3406 but does not exit the surface 3414 can exit elsewhere from the diffusing material 3406, possibly due to leakage of the housing 3408. This flow configuration can result in a more tortuous overall flow path for the gas exiting the vent 3400, thus more likely to dampen or eliminate generated noise. Air can produce impingement but not penetration if the velocity is sufficiently low and the porosity of the surface 3414 is such that surface effects prevent air penetration. In this scenario, the diffusing material 3406 can still reduce the jet effect, as well as reduce noise by allowing sound waves to propagate into the diffusing material 3406 and dissipate.

[0215] The diffusing material 3406 can cause diffusion of the air as it passes through the material, which can absorb energy and / or reduce air velocity. Reducing flow velocity reduces associated noise, often due to turbulence of the flow or impingement of the air jet on a hard surface. The diffusing material 3406 can be a fibrous material similar to that used in filter media (e.g., uncompressed fibers such as polyester fibers) or an open-cell foam. Any material that allows air flow to penetrate at least partially and provides a tortuous path for air flowing through the material can be used for the diffusing material 3406. The diffusing material can be a hygroscopic material such as sintered plastic. The diffusing material can also be hydrophobic and can be processed to have antibacterial properties. One or more of these configurations can be helpful in removing moisture, which can be beneficial in a cleaning process.

[0216] The housing 3408 can have any shape that helps to hold the diffusing material 3406 in place while also providing the desired flow characteristics of the vent 3400. The housing 3408 is illustrated as including a wall configuration that prevents air from flowing out of the housing at all areas directly opposite each of the openings 3420. The housing 3408 can include all structural components that surround the diffusing material 3406, such as the wall 3404 and the wall 3428. The centerlines 3430 are shown along the center axis of each of the channels 3402 and extend to the second wall 3428. If the channels are long enough relative to the intake flow conditions, fully developed flow occurs and the arrows 3422 will be an approximation of the flow vectors through and out of the channels 3402. As the air stream moves away from the channels 3402, the chaotic nature of fluid flow can cause the actual flow to diverge and dissipate. However, vectors (e.g., magnitude and direction) can be used to characterize the flow at a given point. If these vectors were extended, they would eventually intersect a portion of the housing 3408 that has no openings. However, this is not simply the flow vectors that extend generally along the center axis of the respective openings, which, if extended, would encounter a solid wall in the direction of flow. If the cross-sectional area of each of the openings 3420 extends along the respective centerline 3430, an image of this area would extend onto the solid portion of the wall 3428 above the openings in the wall 3428, rather than above the openings in the wall 3428. Thus, there is no opening (e.g., the second opening 3424) in the housing 3408 or the vent 3400 that is in line with the exit vectors or overlaps with the extended area from any of the channels 3402, and air that exits the channels 3402 cannot exit the vent 3400 from the portion of the second wall 3428 that is directly opposite the channels 3402. Instead, the exit 3416 extends in a direction that is at an angle relative to the flow vectors of the channels 3402. This angle can be acute, but in some examples is a right angle (e.g., at a right angle to the exit vectors) or even an obtuse angle. This configuration increases the likelihood that air that exits the channels 3402 will exit the vent 3400 via the opening 3416 along a tortuous path through the diffusing material 3406. As previously mentioned, the exit 3416 can be defined by one or more of the following: a wall of the housing 3408, a surface of the diffusing material, or a surface of another component. The exit 3416 can be directed in any direction as long as it releases air into the environment along a path that does not pass through the diffusing material 3406. In one alternative example, the air stream that exits the exit 3416 can be parallel to the arrows 3422, but can be offset therefrom.

[0217] As shown, the housing 3408 partially defines the opening 3416, and the wall 3404 also partially defines the opening 3416, although the opening 3416 can be entirely defined by the housing 3408 or not defined by the housing 3408 at all. For example, in the latter case, the opening 3416 can be defined by a component other than the housing 3408. Any configuration and location of the opening 3416 that provides an appropriate flow path, including the gap 3412, can be utilized. As shown, the opening 3416 is an annular gap around the periphery of the vent 3400, although the opening 3416 can be any number of openings. For example, it can be desirable to divide the opening 3416 into several openings to increase the stability of the resulting opening. As shown, the opening 3416 can be described as a direct outlet to the environment, although the opening 3416 can be a less direct, or more tortuous, path to the environment. For example, there can be additional structural elements that create a flow path that includes one or more turns before exiting to the environment. Further, the opening 3416 can be in a different orientation relative to the gap 3412 or the wall 3404 than shown. As shown, the flow path through the opening 3416 is substantially at a right angle to the channel 3402 and / or the arrow 3422, although the opening can be at other angles or orientations. For example, the flow path through the opening can be at an obtuse or acute angle to the channel 3402, or can be parallel to the channel 3402 and offset.

[0218] The housing 3408 can also include openings 3424 that are not in line with the passageway 3402. The openings 3424 are shown as having a centerline 3432 on a center axis of the openings 3424 to visually illustrate the orientation of the openings 3424. The centerline 3430 of the passageway 3402 is not aligned with the centerline 3432 of the openings 3424. The openings 3424 (0, 1 or more) can optionally be included to facilitate water removal after the vent 3400 is washed. The openings 3424 can allow water to oscillate out of the vent 3400 and / or allow water to more likely evaporate and exit the vent 3400, where both oscillation and evaporation aid in drying the vent 3400. If included, the openings 3424 are preferably positioned and sized in combination with the diffusing material 3406, the openings 3416 and the gap 3412 such that substantially no air exits the openings 3424 when a therapeutic pressure is applied to the patient interface 3000. To determine the outflow of the openings 3424, a pressure can be applied to the patient interface 3000 and the flow rate through the vent 3400 measured. The openings 3424 can then be completely blocked and the flow rate re-measured. If the flow rate decreases by less than a predetermined percentage, then the air flow through the vent 3400 has not substantially decreased. Preferably, the flow decreases by no more than 5%, more preferably the flow decreases by no more than 3%. In fact, blocking the openings 3424 can not cause a change in the flow rate through the vent 3400. The vent 3400 is designed such that completely blocking the openings 3424 does not substantially change the flow through the vent 3400, even if the diffusing material 3406 is completely blocked, perhaps due to the buildup of water or mucus, the vent 3400 should provide sufficient gaseous flushing.

[0219] The openings 3424 can be formed in a region adjacent to a side of the diffusing material 3406 opposite the side facing the openings 3420. However, the size and position of the openings 3424 can vary. The openings 3424 can have at least two uses - to allow for washing and drying of the vent. First, the openings 3424 can allow a user to wash the diffusing material 3406 by placing the entire vent 3400 under a faucet of running water. To be effective, the openings 3424 are preferably large enough to allow liquid water (e.g., droplets) to enter the housing. Second, the openings 3424 can allow for removal of accumulated liquid after washing or after liquid (e.g., mucus, water, etc.) is inadvertently accumulated during use of the vent. The size of each individual opening 3424 is related to the ability to allow liquid, such as water, to enter and exit the vent. The combined size of all of the openings can determine the washing and drying efficiency of the vent. A combined area of between 20 mm 2 and 80 mm 2 is believed to be capable of sufficient washing and drying. In some examples, the total opening area is preferably between 30 mm 2 and 60 mm2 Between, or even more preferably at 50mm 2 The location of the opening may also be important. Preferably, opening 3424 is spaced apart from and at least partially opposite to opening 3416 relative to the diffuse material 3406. This provides a path for water or liquid flow between opening 3416 and opening 3424, improving the ability to clean and dry the diffuse material 3406. At least in Figure 4A In the embodiment shown, water can be removed at least through the second opening 3424 by shaking or applying centripetal force to the vent 3400.

[0220] The housing 3408 may contain the diffuse material 3406 by any suitable method. For example, the housing 3408 and the diffuse material 3406 may be bonded together (e.g., glued or melted together) or mechanically fixed (e.g., by friction, interference, braking, etc.).

[0221] The housing 3408 can be a single integral piece or multiple pieces joined together to form a single piece. The wall 3404 can be permanently attached to the housing 3408 or integrally formed with the housing 3408. The housing can be attached to the vent 3400 in a non-releasable manner, an attachment not intended to be removed without damage. Non-releasable attachments can include adhesive, ultrasonic welding, hot ironing, one-time snap-fit ​​(e.g., snap-fit ​​designed to break upon separation), initially formed as a single piece, etc. Several benefits can be achieved if the housing 3408 is formed such that the housing 3408 and / or the diffuser 3406 cannot be removed. For example, if the housing 3408 and / or the diffuser 3406 cannot be removed, incorrect user installation or accidental detachment of the vent can be prevented.

[0222] Figure 4B Another configuration of the ventilation port 3400 is shown. (Compared to...) Figure 4A The relevant descriptions of the reference figures also apply here, so they will not be repeated. This configuration of the 3400 ventilation port is similar to... Figure 4A The configuration shown is different except that the air passage 3410 is omitted. Therefore, the gap 3412 extends from one side of the air vent 3400 to the other side.

[0223] Figure 4C Another configuration of the ventilation port 3400 is shown. (Compared to...) Figure 4A The descriptions related to the reference figures also apply here, and therefore will not be repeated. Here, the air passage 3410 is omitted, and instead, component 3426 is shown, which can fix the diffuse material 3406 and / or the housing 3408.

[0224] Figure 4DAnother configuration of an air exchange 3400 is shown. The description associated with reference numerals of Figure 4A apply here as well, and are not repeated. This figure differs from Figure 4A in the location of the openings 3424. This figure also shows that the openings 3416 can be continuous around the periphery of the air exchange 3400. The openings 3424 can also be continuous, but are preferably discontinuous from each other and / or from the openings 3416.

[0225] Figure 4E Another configuration of an air exchange 3400 is shown. The description associated with reference numerals of Figure 4A apply here as well, and are not repeated. In this configuration, the channels 3402 communicate with and are arrayed around the air channels 3410, resulting in an overall toroidal structure for the air exchange 3400 as compared to the planar structure of Figure 4A-4D . In other words, Figure 4A-4D the channels 3402 in Figure 4E are in a planar or near-planar wall 3404, while the wall 3404 is cylindrical, and the gas exiting the air exchange 3400 exits along a cylindrical axis, indicated by a dashed line.

[0226] Figure 4F Another configuration of an air exchange 3400 is shown. The description associated with reference numerals of Figure 4A apply here as well, and are not repeated. Figure 4F Similar to Figure 4E except that in Figure 4F the openings 3416 are provided at both ends of the diffusing material 3406, but in Figure 4E the openings 3416 are provided at only one end of the diffusing material 3406.

[0227] In each of Figure 4A-4F the arrows shown through the diffusing material 3406 are conceptual illustrations of air flow through the diffusing material 3406, and can not represent actual air flow through the diffusing material 3406. In general, each of these arrows shows air exiting the channels 3402, entering the diffusing material 3406 via the surface 3414, exiting the diffusing material via the surface 3414, flowing through the gap 3412, and then flowing to the environment via the openings 3416.

[0228] Figure 4G-4I Another configuration of an air exchange 3400 is shown. The description associated with reference numerals of Figure 4A apply here as well, and are not repeated, unless otherwise noted. Figure 4G An example of an air exchange 3400 is shown in perspective view, where the air exchange 3400 is an insertable and / or removable component.Figure 4H is a top view with the top cover 3440 omitted so that the internal structure is visible. Figure 4I is Figure 4H is a cross-sectional view of Figure 4B but with the top cover included. This configuration of the air exchange 3400 is similar to that shown in Figure 4I where the air channel 3410 is omitted (but can be included if desired). As best seen in Figure 4H and Figure 4I the support 3434 is shown as a continuous wall that bisects the gap 3412, extending uninterrupted from one side to the other. However, the support 3434 need not be continuous and can be formed of one or more discontinuous supports (one or more gaps can be provided in the support 3434).

[0229] Another difference is the location of the openings 3416. The openings 3416 are offset in a direction away from the surface that includes the openings 3420, rather than being substantially in line with the gap 3412, which results in a second portion 3412A of the gap 3412 that surrounds the periphery of the diffusing material 3406. With this arrangement, air can flow into the surface 3414 and out the side surface 3436 of the diffusing material 3406 before flowing out the openings 3416. Air can also flow through the gap 3412 and the second portion 3412A without passing through the diffusing material 3406. Due to the chaotic and unpredictable nature of single molecule flow, the actual air flow can be a combination of the two flow paths. However, by providing two flow paths, the air exchange 3400 can provide sufficient flow even if the diffusing material 3406 is clogged.

[0230] Figure 4G and Figure 4I shows a groove 3438 around the perimeter of the air exchange 3400. Such a groove can allow the air exchange 3400 to be retained in a mating hole, preferably in a replaceable manner. For example, if the hole is made of a relatively flexible material such as silicone, the air exchange 3400 can be easily removed for cleaning or replacement in a simple manner.

[0231] Figure 4J and Figure 4K shows aspects similar to Figure 4I but with a deflector 3442 added. In Figure 4J the deflector 3442 is shown as a solid, flat barrier that prevents air from flowing directly through the diffusing material 3406 to the wall 3428 (e.g., out from the opposite side of the surface 3414). In Figure 4K the deflector 3442 is curved in such a way that it can create a vortex with Figure 4JThe flat deflectors shown in FIGS. 34A and 34B provide a smoother transition beyond the sides of the diffusing material 3406 than the curved deflectors shown in FIGS. 33A and 33B. Although the deflectors 3442 are shown in FIGS. 34A and 34B as being flat, they can be curved or otherwise shaped as desired to achieve the desired flow characteristics. For both forms of the deflectors 3442, any suitable method of creating the deflectors 3442 within the diffusing material 3406 can be used. For example, appropriately shaped cutouts in the sides of the diffusing material 3406 can allow the deflectors 3442 to be inserted. Alternatively, the diffusing material 3406 can be composed of multiple pieces that are then joined around the diffusing material 3406. Figure 4K

[0232] In one aspect, the diffusing material 3406 can be removable. For example, if the cover 3440 is releasably attached, the diffusing material 3406 can be held by the cover 3440 by mechanical retention. If the cover 3440 is removed, the diffusing material 3406 can also be removed. However, in another aspect, the diffusing material 3406 can be non-removable. For example, if the cover 3440 is attached to the vent 3400 such that the cover can only be removed by damaging the vent 3400, the diffusing material 3406 can be considered non-removable. Alternatively, the diffusing material 3406 can be permanently attached within the vent 3400, such as by an adhesive, such that the diffusing material 3406 would be damaged in the process of removal. Even if the cover 3440 is removable without damage, the diffusing material 3406 can be secured in a manner that would damage or destroy the diffusing material 3406 if removed, thereby making the diffusing material 3406 non-removable.

[0233] Although the boundary of the diffusing material 3406 is described as the surface 3414, it can be different than a surface of a solid. The diffusing material 3406 can have a number of openings or gaps that allow the curved flow to pass through the diffusing material. Thus, the surface 3414 can also be considered a boundary of the diffusing material 3406.

[0234] The vent 3400 can produce a relatively low noise level or dampen the noise produced before it propagates to the user. Preferably, the sound produced is less than 28 dB(A). For example, the sound can be 20-28 dB(A), 22-26 dB(A), or about 24 dB(A). These sound levels can be low enough that neither the user nor a bed partner is disturbed.

[0235] 4.3.5 Decoupling structure

[0236] In one form, the patient interface 3000 includes at least one decoupling structure, such as a swivel or ball joint.

[0237] 4.3.6 Connection port

[0238] ​Connection port 3600 allows connection to air circuit 4170.

[0239] 4.3.7 Forehead support

[0240] In one form, the patient interface 3000 includes a forehead support 3700.

[0241] 4.3.8 Anti-asphyxia valve

[0242] In one form, the patient interface 3000 includes an anti-asphyxia valve.

[0243] 4.3.9 Port

[0244] In one form of the 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 direct measurement of a property of the gas within the plenum chamber 3200, such as pressure.

[0245] 4.4 Glossary

[0246] To achieve the purposes of the present technology, one or more of the following definitions can apply in some forms of the present technology. In other forms of the present technology, alternative definitions can apply.

[0247] 4.4.1 General

[0248] Air: In some forms of the technology, air can be taken to mean atmospheric air, and in other forms of the technology, air can be taken to mean some other combination of breathable gas, for example atmospheric air enriched with oxygen.

[0249] Ambient: In some forms of the present technology, the term ambient can have the following meanings (i) the exterior of the therapy system or patient, and (ii) the immediate surroundings of the therapy system or patient.

[0250] For example, the ambient humidity with respect to a humidifier can be the humidity of the air immediately surrounding the humidifier, for example the humidity in the room in which the patient is sleeping. This ambient humidity can be different to the humidity outside the room in which the patient is sleeping.

[0251] In another example, the ambient pressure can be the pressure immediately surrounding or outside the body.

[0252] In some forms, ambient (e.g. acoustic) noise can be taken to mean the background noise level in the room in which the patient is located, other than noise produced for example by the RPT device or from the mask or patient interface. Ambient noise can be produced by sound sources outside the room.

[0253] Auto-Positive Airway Pressure (APAP) therapy: CPAP therapy in which the therapy pressure is automatically adjustable between a minimum and a maximum, e.g. different for each breath, depending on whether or not there are indications of SBD events.

[0254] Continuous Positive Airway Pressure (CPAP) therapy: respiratory pressure therapy in which the therapy pressure can be approximately constant throughout the patient's respiratory cycle. In some forms, the pressure at the entrance to the airways will be slightly higher during exhalation and slightly lower during inhalation. In some forms, the pressure will vary between different breath cycles of the patient, e.g. increase in response to detection of indications of partial airway obstruction, and decrease in the absence of indications of partial airway obstruction.

[0255] Flow: volume (or mass) of air delivered per unit of time. Flow can refer to an instantaneous quantity. In some cases, reference to flow will be reference to a scalar quantity, i.e. a quantity having only magnitude. In other cases, reference to flow will be reference to a vector quantity, i.e. a quantity having both magnitude and direction. Flow can be given the symbol Q. 'Flow' is sometimes simply abbreviated to 'flow' or "air flow".

[0256] In the example of a patient breathing, flow can be nominally positive for the inhalation portion of the patient's respiratory cycle, and thus negative for the exhalation portion of the patient's respiratory cycle. Total flow (Qt) is the flow of air leaving the RPT device. Ventilation flow (Qv) is the flow of air leaving the vent to allow washout of exhaled gases. Leak flow (Ql) is the flow of air leaking from the patient interface system. Respiratory flow (Qr) is the flow of air received into the patient's respiratory system.

[0257] Humidifier: the word humidifier will mean a humidification apparatus constructed and arranged or configured to have the ability to provide a therapeutic beneficial amount of water (H20) vapour to an air flow to relieve a patient's medical respiratory condition.

[0258] Leak: the word leak will be taken to mean an undesirable flow of air. In one example, a leak can occur due to an imperfect seal between a mask and a patient's face. In another example, a leak can occur in a swivel elbow to ambient.

[0259] Noise, conducted (acoustic): conducted noise herein refers to noise brought to the patient through the pneumatic path, such as the air circuit and 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.

[0260] Noise, Radiated (acoustic): Radiated noise herein refers to noise imparted to the patient through the surrounding air. In one form, radiated noise can be quantified by measuring the sound power / pressure level of the object in question according to ISO 3744.

[0261] Noise, Ventilatory (acoustic): Ventilatory noise herein refers to noise produced by the flow of air through any vent (e.g. a vent in a patient interface).

[0262] Patient: A human, whether or not they suffer from a respiratory disease.

[0263] Pressure: Force per unit area. Pressure can be measured in units including cm H20, g-f / cm 2 and hectopascals. 1 cm H20 is equivalent to 1 g-f / cm 2 and is approximately 0.98 hectopascals. In this specification, pressure is given in units of cm H20 unless otherwise stated.

[0264] Pressure in a patient interface is given the symbol Pmand pressure in therapy is given the symbol Pt, which represents the target value achieved by the mask pressure Pmat the current instant in time.

[0265] Respiratory Pressure Therapy (RPT): Application of a supply of air at a therapeutic pressure, which is typically positive with respect to atmospheric pressure, to the entrance of the airways.

[0266] Ventilator: A mechanical device that provides pressure support to a patient to perform some or all of the work of breathing.

[0267] 4.4.1.1 Materials

[0268] Silicone or Silicone Elastomer: A synthetic rubber. In this specification, reference to silicone refers to Liquid Silicone Rubber (LSR) or Compression Molded Silicone Rubber (CMSR). One form of LSR that is commercially available is SILASTIC (including the range of products sold under this trademark) manufactured by Dow Corning. Another manufacturer of LSR is Wacker. Unless otherwise specified to the contrary, an exemplary form of LSR has a Shore A (or Type A) indentation hardness in the range of about 35 to about 45 as measured using ASTM D2240.

[0269] Polycarbonate: A thermoplastic polymer of bisphenol A carbonate.

[0270] 4.4.1.2 Mechanical Properties

[0271] Resilience: The ability of a material to absorb energy when elastically deformed and to release the energy when unloaded.

[0272] Resilient: will release substantially all of its energy when deflated. Includes certain silicones and thermoplastic elastomers.

[0273] Hardness: the ability of a material to resist deformation by itself (e.g. by Young's modulus, or the indentation hardness scale measured on a standard sample size).

[0274] • 'Soft' materials can include silicones or thermoplastic elastomers (TPEs), and can deform easily, e.g. under finger pressure.

[0275] • 'Hard' materials can include polycarbonate, polypropylene, steel or aluminium, and can not deform easily, e.g. under finger pressure.

[0276] Hardness (or stiffness) of a structure or component: the ability of a structure or assembly to resist deformation in response to an applied load. The load can be a force or a moment, e.g. compression, tension, bending or torsion. A structure or assembly can provide different resistance in different directions.

[0277] Soft structure or component: a structure or assembly that will change shape, e.g. bend, when left to support its own weight over a relatively short period of time, such as 1 second.

[0278] Rigid structure or component: a structure or assembly that will not substantially change shape when subjected to loads typically encountered in use. One example of such use can be to set up and maintain a patient interface in a sealing relation with an entrance to a patient's airways, e.g. under loads of about 20 to 30 cm H20 pressure.

[0279] As one example, an I-beam can comprise different bending stiffness (resistance to bending loads) in a first direction compared to a second, orthogonal direction. In another example, a structure or assembly is soft in a first direction and rigid in a second direction.

[0280] 4.4.2 Respiratory cycle

[0281] Apnoea: according to some definitions, an apnoea is considered to occur when the flow rate falls below a predetermined threshold for a sustained period of time, e.g. 10 seconds. An apnoea is said to have occurred when some obstruction of the airways is such that air cannot flow despite efforts of the patient. A central apnoea is said to have occurred when a cessation of breathing is detected due to a reduction or absence of breathing efforts despite the airways being open. A mixed apnoea is considered to occur when a reduction or absence of breathing efforts coincides with an obstructed airway.

[0282] Respiratory rate: the patient's spontaneous respiratory rate, usually measured in breaths per minute.

[0283] Duty cycle: the ratio of the inspiration time (Ti) to the total breath time (Ttot).

[0284] Effort (breathing): the work done by a spontaneously breathing subject in attempting to breathe.

[0285] Exhalation portion of the breath cycle: the time period from the start of the exhalation flow to the start of the inhalation flow.

[0286] Flow limitation: flow limitation will be taken to mean a condition in the patient's breathing in which an increase in the patient's effort does not produce a corresponding increase in flow. Flow limitation occurs during the inspiratory portion of the breath cycle, it can be described as inspiratory flow limitation. Flow limitation occurs during the expiratory portion of the breath cycle, it can be described as expiratory flow limitation.

[0287] Inspiratory waveform of the type:

[0288] (i) flat: with an ascending followed by a relatively flat portion, followed by a descending.

[0289] (ii) M-shaped: with two local peaks, one at the leading edge and one at the trailing edge, and a relatively flat portion between the two peaks.

[0290] (iii) chair-shaped: with a single local peak, the peak being at the leading edge, followed by a relatively flat portion.

[0291] (iv) reverse chair-shaped: with a relatively flat portion, followed by a single local peak, the peak being at the trailing edge.

[0292] Hypopnea: according to some definitions, a hypopnea will be taken to mean a decrease in flow, but not a cessation of flow. In one form, a hypopnea will be said to have occurred when the flow falls below a threshold value for a period of time. A central hypopnea will be said to have occurred when a hypopnea is detected due to a decrease in respiratory effort. In one form for an adult, either of the following can be taken to mean a hypopnea:

[0293] (i) a 30% reduction in the patient's breathing for at least 10 seconds plus an associated 4% desaturation; or

[0294] (ii) a reduction in the patient's breathing (but at least 50%) for at least 10 seconds, accompanied by an associated at least 3% desaturation or arousal.

[0295] Hyperpnea: an increase in flow to a level above normal flow.

[0296] Inspiratory portion of the breath cycle: the time period from the start of the inhalation flow to the start of the exhalation flow will be taken to mean the inspiratory portion of the breath cycle.

[0297] Open (airway): The degree to which the airway is open, or the degree to which the airway is open. An open airway is open. Airway openness can be quantified, for example with a value of one (1) for open, and a value of zero (0) for closed (obstructed).

[0298] Positive end-expiratory pressure ventilation (PEEP): The pressure above atmospheric pressure in the lungs present at the end of expiration.

[0299] Leak flow (Qpeak): The maximum value of flow during the expiratory portion of the breath flow waveform.

[0300] Breath flow, patient air flow, breath air flow (Qr): These terms are to be understood to mean the RPT device's estimate of the breath flow, as opposed to the "true breath flow" or "true breath flow" which is the actual breath flow experienced by the patient, typically expressed in litres per minute.

[0301] Tidal volume (Vt): The volume of air inhaled or exhaled during normal breathing when no extra effort is applied.

[0302] (Inspiration) time (Ti): The duration of the inspiratory portion of the breath flow waveform.

[0303] (Exhalation) time (Te): The duration of the expiratory portion of the breath flow waveform.

[0304] (Overall) time (Ttot): The total duration between the start of the inspiratory portion of the breath flow waveform and the start of the subsequent inspiratory portion of the breath flow waveform.

[0305] Typical recent ventilation: The ventilation values around which recent values on some predetermined timescale tend to cluster, that is, a measure of the tendency of recent ventilation values to cluster.

[0306] Upper airway obstruction (UAO): Includes both partial and total upper airway obstruction. This can be associated with a state of flow limitation in which flow increases only slightly or can even decrease as the pressure difference across the upper airway increases (Starling resistance behaviour).

[0307] Ventilation (Vent): A measure of the flow of gas exchanged by the patient's respiratory system. The measure of ventilation can include one or both of the inspiratory and expiratory flow per unit time. When expressed in volume / minute, this quantity is often referred to as "minute ventilation". Minute ventilation is sometimes given simply as volume, understood to be volume / minute.

[0308] 4.4.3 Ventilation

[0309] Adaptive Servo Ventilation (ASV): A servo ventilator with a variable target ventilation rather than a fixed target ventilation. The variable target ventilation can be derived from some characteristics of the patient, such as the patient's breathing characteristics.

[0310] Backup Frequency: A ventilator parameter that establishes the minimum respiratory frequency (typically in breaths per minute) that the ventilator will deliver to the patient if not caused by spontaneous respiratory effort.

[0311] Cycle: The termination of the inspiratory phase of a breath by a ventilator. When a ventilator will deliver breaths to a spontaneously breathing patient, the ventilator is said to cycle to stop delivering breaths at the end of the inspiratory portion of the breathing cycle.

[0312] Expiratory Positive Airway Pressure (EPAP): The base pressure to which a varying pressure in a breath is added to produce the desired mask pressure that the ventilator will attempt to obtain at a given time.

[0313] End Expiratory Pressure (EEP): The desired mask pressure that the ventilator will attempt to obtain at the end of the expiratory portion of a breath. If the pressure waveform template (Φ) is zero at the end of expiration, i.e., when Φ = 1 (Φ) = 0, then the EEP is equal to the EPAP.

[0314] Inspiratory Positive Airway Pressure (IPAP): The maximum desired mask pressure that the ventilator will attempt to obtain during the inspiratory portion of a breath.

[0315] Pressure Support: A number that indicates the increase in pressure during inspiration by a ventilator over the pressure during expiration by the ventilator, and generally means the difference in pressure between the maximum during inspiration and the base pressure (e.g., PS = IPAP - EPAP). In some cases, pressure support means the difference that the ventilator plans to obtain, rather than the difference that it actually obtains.

[0316] Servo Ventilator: A ventilator that measures the patient's ventilation, has a target ventilation, and adjusts the pressure support level to bring the patient's ventilation toward the target ventilation.

[0317] Spontaneous / Timed (S / T): A mode of a ventilator or other device that attempts to detect the onset of a breath by a spontaneously breathing patient. However, if the device cannot detect a breath within a predetermined time period, the device will automatically initiate the delivery of a breath.

[0318] Swing: An equivalent term for pressure support.

[0319] Triggered: When a ventilator delivers an air breath to a spontaneously breathing patient, it is said to be triggered to do so by the patient's effort at the onset of the inspiratory portion of the breathing cycle.

[0320] Typical recent ventilation: The typical recent ventilation Vtyp is a recent measurement of ventilation that tends to cluster around a value. For example, a measure of the tendency of ventilation measurements to cluster in the recent history can be a suitable value for the typical recent ventilation.

[0321] 4.4.4 Anatomy

[0322] 4.4.4.1 Anatomy of the face

[0323] Ala: The outer lateral wall or "wing" of each nostril (plural: alae)

[0324] Alar angle:

[0325] Alar crest: The most lateral point on the ala.

[0326] Alar curve (or alar crest) point: The point at the last part of the curved base of each ala, found in the fold formed by the junction of the ala with the cheek.

[0327] Auricle: The entire externally visible part of the ear.

[0328] (Nasal) skeletal framework: The skeletal framework of the nose includes the nasal bones, frontal process of the maxilla, and nasal part of the frontal bone.

[0329] (Nasal) cartilaginous framework: The cartilaginous framework of the nose includes the septum, lateral, greater, and lesser cartilages.

[0330] Columella: The skin strip separating the nostrils and extending from the tip of the nose to the upper lip.

[0331] Columellar angle: The angle between a line drawn through the midpoint of the nostril and a line drawn perpendicular to the Frankfort horizontal (both lines intersect at the subnasal point).

[0332] Frankfort horizontal: A line extending from the lowest point of the orbital margin to the left ear canal. The ear canal is the deepest point in the notch on the upper part of the tragus of the auricle.

[0333] Glabella: The most prominent point in the median sagittal plane of the forehead, located on the soft tissue.

[0334] Lateral nasal cartilage: A generally triangular cartilaginous plate. Its superior border is attached to the nasal bone and frontal process of the maxilla, and its inferior border is connected to the greater alar cartilage.

[0335] Greater alar cartilage: A cartilaginous plate located inferior to the lateral nasal cartilage. It curves around the anterior part of the nostril. Its posterior end is connected to the frontal process of the maxilla by a tough fibrous membrane containing three or four small cartilages that comprise the alar crease.

[0336] Naris (nose eye): The approximately elliptical aperture that forms the entrance to the nasal cavity. The singular form of the naris is naris (nose eye). The nares are separated by the nasal septum.

[0337] Nasolabial groove or nasolabial fold: Skin fold or groove extending from each side of the nose to the corner of the mouth, which separates the cheeks from the upper lip.

[0338] Nasolabial angle: The angle between the columella and the upper lip (while intersecting at the subnasale point).

[0339] Infralobular point: The lowest point at which the helix attaches to the facial skin.

[0340] Supralobular point: The highest point at which the helix attaches to the facial skin.

[0341] Nasal tip point: The most protruding point or tip of the nose, which can be identified in a side view of the head.

[0342] Philtrum: Midline groove extending from the lower border of the nasal septum to the lip superior in the region of the upper lip.

[0343] Prementale: Midpoint of the most forward part of the chin, located on soft tissue.

[0344] Ridge (nose): The midline protrusion of the nose extending from the sellion to the tip of the nose.

[0345] Sagittal plane: Vertical plane passing from the front (anterior) to the back (posterior) that divides the body into right and left halves.

[0346] Sellaion: The most concave point, located on soft tissue, covering the region of the frontonasal suture.

[0347] Septal cartilage (nose): The nasal septal cartilage forms part of the septum and divides the anterior part of the nasal cavity.

[0348] Superior lateral triangle: Point at the lower margin of the alar base where the alar base meets the skin of the upper (superior) lip.

[0349] Subnasale: Point, located on soft tissue, where the columella meets the upper lip in the median sagittal plane.

[0350] Submental pogonion: Point on the midline of the lower lip at the greatest concavity between the midpoint of the lower lip and the soft tissue prementale.

[0351] 4.4.4.2 Anatomy of the skull

[0352] Frontal bone: The frontal bone includes a large vertical part (frontal squama) which corresponds to the region called the forehead.

[0353] Mandible: The mandible forms the lower jaw. The mental protuberance is the bony protuberance of the lower jaw that forms the chin.

[0354] Maxilla: The maxilla forms the upper jaw and is located above the mandible and below the eye sockets. The frontal process of the maxilla projects upward from the sides of the nose and forms part of the lateral border.

[0355] Nasal bone: The nasal bone is an oval-shaped bone that varies in size and form among individuals; it is located side by side in the middle and upper part of the face and forms the "bridge" of the nose with its junction.

[0356] Nasion: The junction of the frontal bone and the two nasal bones, directly between the eyes and in the depressed area of the upper part of the bridge of the nose.

[0357] Occipital bone: The occipital bone is located at the back and lower part of the skull. It includes an oval foramen (foramen magnum) through which the cranial cavity communicates with the spinal canal. The curved plate behind the foramen magnum is the squama occipitalis.

[0358] Orbital: The bony cavity in the skull that houses the eyeball.

[0359] Parietal bone: The parietal bone is the bone that, when joined together, forms the roof of the skull and the sides.

[0360] Temporal bone: The temporal bone is located at the bottom and on the sides of the skull and supports the part of the face known as the temple.

[0361] Zygomatic bone: The face includes two zygomatic bones, which are located on the upper and lateral parts of the face and form the protruding parts of the cheeks.

[0362] 4.4.4.3 Anatomy of the respiratory system

[0363] Diaphragm: A muscle sheet that extends across the bottom of the rib cage. The diaphragm separates the thoracic cavity, which contains the heart, lungs, and ribs, from the abdominal cavity. As the diaphragm contracts, the volume of the thoracic cavity increases and air is drawn into the lungs.

[0364] Larynx: The larynx or voice box houses the vocal cords and connects the lower part of the pharynx (hypopharynx) to the trachea.

[0365] Lungs: The respiratory organs of humans. The conducting region of the lungs includes the trachea, bronchi, bronchioles, and terminal bronchioles. The respiratory region includes respiratory bronchioles, alveolar ducts, and alveoli.

[0366] Nasal cavity: The nasal cavity (or nasal fossa) is the large, air-filled space in the middle of the face, above and behind the nose. The nasal cavity is divided into two by a vertical wing called the nasal septum. On the sides of the nasal cavity are three horizontal branches, which are called conchae (singular "concha"). The front of the nasal cavity is the nose, while the back joins into the nasopharynx via the internal naris.

[0367] Pharynx: The part of the laryngopharynx located immediately below (inferior to) the nasal cavity and above the esophagus and larynx. The pharynx is conventionally divided into three parts: the nasopharynx (superior pharynx) (the nasal part of the pharynx), the oropharynx (middle pharynx) (the oral part of the larynx), and the laryngopharynx (inferior pharynx).

[0368] 4.4.5 Patient interface

[0369] Anti-asphyxia valve (AAV): A component or subassembly of a mask system that reduces the risk of excessive C02 rebreathing by the patient by venting to atmosphere in a failsafe manner.

[0370] Elbow: An elbow is an example of a structure that changes the direction of the axis of air flow by a certain angle. In one form, the angle can be approximately 90 degrees. In another form, the angle can be greater or less than 90 degrees. The elbow can have an approximately circular cross-section. In another form, the elbow can have an elliptical or rectangular cross-section. In certain forms, the elbow can be rotatable relative to the mating component, for example, by about 360 degrees. In certain forms, the elbow can be detachable from the mating component, for example, by a snap connection. In certain forms, the elbow can be assembled to the mating component by a snap connection during manufacture, but can not be detachable by the patient.

[0371] Frame: A frame will be taken to mean a mask structure that carries the tensile load between two or more connection points with headgear. A mask frame can be a non-airtight load carrying structure in a mask. However, some forms of mask frame can also be airtight.

[0372] Headgear: Headgear will be taken to mean a form of positioning and stabilising structure designed for use on the head. For example, headgear can comprise a set of one or more support poles, straps and stiffening rods configured to position and hold a patient interface on the face of a patient in a position for use in the delivery of respiratory therapy. Some straps are formed from soft, pliable, elastic materials such as foams and fabric laminates.

[0373] Membrane: A membrane will be taken to mean a typically thin element that is preferably substantially inelastic against bending but is elastic against stretching.

[0374] Plenum chamber: A mask plenum chamber will be taken to mean a portion of a patient interface having walls that enclose a volume of space that in use has air pressurised within it to above atmospheric pressure. A shell can form part of the walls of a mask plenum chamber.

[0375] Seal: Can be a noun form of the term (a "seal") or a verb form of the term (to "seal"). Two elements can be constructed and / or arranged to seal between them or achieve a "seal" between them without a separate "seal" element per se.

[0376] Shell: A shell will be considered to mean a curved and relatively thin structure with bendable, stretchable, and compressible rigidity. For example, a curved structural wall of a face mask can be a shell. In some forms, the shell can be multi-faceted. In some forms, the shell can be multi-faceted. In some forms, the shell can be air-tight. In some forms, the shell can not be air-tight.

[0377] Reinforcement: A reinforcement will be considered to mean a structural component designed to increase the bending resistance of another component in at least one direction.

[0378] Support: A support will be considered to mean a structural component designed to increase the compressive resistance of another component in at least one direction.

[0379] Swivel (noun): A subcomponent of an assembly configured to rotate about a common axis, preferably independently, preferably at low torque. In one form, the swivel can be configured to rotate through an angle of at least 360 degrees. In another form, the swivel can be configured to rotate through an angle of less than 360 degrees. When used in the context of an air delivery conduit, the subcomponent of the assembly preferably comprises a pair of mating cylindrical conduits. There can be little or no air leakage from the swivel in use.

[0380] Tie (noun): A structure designed to resist tension.

[0381] Vent (noun): A structure that allows air flow from the interior of a face mask or conduit to ambient air to allow clinically effective flushing of exhaled gases. For example, clinically effective flushing can involve flow rates of about 10 liters per minute to about 100 liters per minute, depending on the face mask design and treatment pressure.

[0382] 4.4.6 Shape of a structure

[0383] A product according to the present technology can include one or more three-dimensional mechanical structures, such as a face mask cushion or a propeller. Three-dimensional structures can be joined by two-dimensional surfaces. These surfaces can be distinguished using labels to describe the relevant surface orientation, location, function, or some other characteristic. For example, a structure can include one or more of an anterior surface, a posterior surface, an interior surface, and an exterior surface. In another example, a seal-forming structure can include a (e.g., external) surface that contacts the face and a separate (e.g., underside or internal) surface that does not contact the face. In another example, a structure can include a first surface and a second surface.

[0384] To aid in describing the shape of three-dimensional structures and surfaces, first consider a cross-section through a point p of a surface. See Figure 3B-3F , which show examples of cross-sections at a point p on a surface and the resulting planar profile. Figure 3B-3FThe outward normal vector at point p is also shown. The outward normal vector at point p is away from the surface. In some instances, the surface is described from the viewpoint of an imaginary little person standing upright on the surface.

[0385] 4.4.6.1 Curvature in one dimension

[0386] The curvature of a plane curve at p can be described with a sign (e.g., positive, negative) and a quantity (e.g., the reciprocal of the radius of the circle that only touches the curve at p).

[0387] Positive curvature: If the curve at point p turns outward toward the normal, then the curvature at that point will be positive (if the imagined figures leave point p, they must walk uphill). See also Figure 3B (and Figure 3C Compared to relatively large positive curvature) and Figure 3C (and Figure 3B (Compared to relatively small positive curvature). Such curves are often referred to as concave surfaces.

[0388] Zero curvature: If the curve at point p is a straight line, then the curvature will be zero (if you imagine a little person leaving point p, they can walk horizontally without going up or down). See also Figure 3D .

[0389] Negative curvature: If the curve at point p deviates from the outward normal, then the curvature in that direction at that point will be negative (if you imagine little figures leaving point p, they must go downhill). See also Figure 3E (and Figure 3F Compared to relatively small negative curvature) and Figure 3F (and Figure 3E (Compared to relatively large negative curvature). Such curves are often referred to as convex surfaces.

[0390] 4.4.6.2 Curvature of Two-Dimensional Surfaces

[0391] A description of the shape at a given point on a two-dimensional surface according to the present technology may include multiple normal cross sections. These cross sections may cut through the surface in a plane including an outward normal (“normal plane”), and each cross section may be cut in a different direction. Each cross section produces a planar curve with a corresponding curvature. The different curvatures at that point may have the same sign or different signs. Each curvature at that point has a quantity, for example, a relatively small quantity. Figure 3B-3F A planar curve in a plane can be an instance of multiple cross-sections at a specific point.

[0392] Principal curvature and principal direction: The direction of the normal plane to which the curvature of the curve reaches its maximum and minimum values ​​is called the principal direction. Figure 3B-3F In the example, the maximum curvature occurs Figure 3BThe minimum occurs at p and the maximum at q. Figure 3F Thus Figure 3B and Figure 3F is the cross-section in the principal direction. The principal curvature at p is the curvature in the principal direction.

[0393] Region of a surface: a set of points connected on a surface. The set of points in a region can have similar characteristics, e.g. curvature or sign.

[0394] Saddle region: a region in which the principal curvatures have opposite signs at each point, i.e. one sign is positive and the other sign is negative (according to the direction in which the imaginary individual turns, they can walk up or down).

[0395] Dome region: a region in which the principal curvatures have the same sign at each point, e.g. both positive (“concave dome”) or both negative (“convex dome”).

[0396] Cylindrical region: a region in which one principal curvature is zero (or, e.g. within manufacturing tolerances, zero) and the other principal curvature is non-zero.

[0397] Planar region: a region of a surface in which both principal curvatures are zero (or, e.g. within manufacturing tolerances, zero).

[0398] Edge of a surface: the boundary or limit of a surface or region.

[0399] Path: in certain forms of the technology, ‘path’ will mean a path in the mathematical-topological sense, e.g. a continuous space curve on a surface from f(0) to f(l). In certain forms of the technology, ‘path’ can be described as a route or course, including e.g. a set of points on a surface. (The path of an imaginary individual is a path in which they walk on the surface and is analogous to a garden path).

[0400] Path length: in certain forms of the technology, ‘path length’ will be the distance along a surface from f(0) to f(l), i.e. the distance along a path on a surface. There can be more than one path between two points on a surface and such paths can have different path lengths. (The path length of an imaginary individual will be the distance they walk along a path on a surface).

[0401] Straight-line distance: the straight-line distance is the distance between two points on a surface, but without regard to the surface. In a planar region, there can be a path on the surface with the same path length as the straight-line distance between two points on the surface. In a non-planar surface, there can not be a path with the same path length as the straight-line distance between two points. (For an imaginary individual, the straight-line distance will correspond to the distance as a ‘straight line’).

[0402] 4.4.6.3 Space Curve

[0403] Space Curve: Unlike a planar curve, a space curve does not have to lie in any particular plane. A space curve can be closed, i.e., have no endpoints. A space curve can be thought of as a one-dimensional slice of three-dimensional space. An imaginary person walking on a DNA helix chain walks along a space curve. A typical human left ear includes a helix, whose left-hand helix, see Figure 3Q , a typical human right ear includes a helix, whose right-hand helix, see Figure 3R . Figure 3S A right-hand helix is shown. The edges of a structure, e.g., the edges of a membrane or thruster, can follow a space curve. In general, a space curve can be described by the curvature and torsion at each point on the space curve. Torsion is a measure of how the curve deviates from a surface. Torsion has a sign and a magnitude. The torsion at a point on a space curve can be characterized with reference to the tangent, normal, and binormal vectors at that point.

[0404] Tangent Unit Vector (or Unit Tangent Vector): For each point on a curve, the vector at that point indicates the direction and magnitude from that point. The tangent unit vector is a unit vector pointed in the same direction as the curve at that point. If an imaginary person were to fly along the curve and stop at a particular point, the direction of the tangent vector is the direction it would be heading.

[0405] Unit Normal Vector: As the imaginary person moves along the curve, the tangent vector itself changes. The unit vector pointed in the same direction as the tangent vector is changing is called the unit principal normal vector. It is perpendicular to the tangent vector.

[0406] Binormal Unit Vector: The binormal unit vector is perpendicular to the tangent vector and the principal normal vector. Its direction can be determined by the right-hand rule (see, e.g., Figure 3P ) or, alternatively, by the left-hand rule ( Figure 3O ).

[0407] Osculating Plane: The plane containing the unit tangent vector and the unit principal normal vector. See Figure 3O and 3P .

[0408] Torsion of a Space Curve: The torsion at a point on a space curve is the rate of change of the binormal vector at that point. It measures how much the curve deviates from the osculating plane. A space curve lying on a plane has zero torsion. A space curve that deviates relatively little from the osculating plane will have a relatively small torsion magnitude (e.g., a helical path that is slightly tilted). A space curve that deviates relatively much from the osculating plane will have a relatively large torsion magnitude (e.g., a helical path that is sharply tilted). See Figure 3S , although T2> T1, at Figure 3Sthe top spiral coil of the right-hand helix. The torque magnitude of the bottom spiral coil of the right-hand helix is greater than Figure 3S the top spiral coil of the right-hand helix. The torque magnitude of the bottom spiral coil of the right-hand helix is greater than

[0409] Reference is made to Figure 3P the right-hand rule, a spatial curve turning in the direction of the right-hand binormal can be considered to have a right-hand positive torque (e.g., a right-hand helix as shown in Figure 3S . A spatial curve turning away from the direction of the right-hand binormal can be considered to have a right-hand negative torque (e.g., a left-hand helix).

[0410] Also and with reference to the left-hand rule (see Figure 3O ), a spatial curve turning in the direction of the left-hand binormal can be considered to have a left-hand positive torque (e.g., a left-hand helix). Thus, a left-hand positive torque is equivalent to a right-hand negative torque. See Figure 3T

[0411] 4.4.6.4 Holes

[0412] A surface can have a one-dimensional hole, e.g., a hole defined by a planar curve or by a spatial curve. A thin structure (e.g., a membrane) having a hole can be described as having a one-dimensional hole. See, e.g., the one-dimensional hole in the surface of the structure shown in Figure 3I , which is defined by a planar curve.

[0413] A structure can have a two-dimensional hole, e.g., a hole defined by a surface. For example, an inflatable tire has a two-dimensional hole defined by the inner surface of the tire. In another example, a bladder having a cavity for air or gel has a two-dimensional hole. See, e.g., the cushion of Figure 3L and the catheter of Figure 3M passing through it in Figure 3N , where the inner surface defines the indicated two-dimensional hole. In another example, a catheter can include a one-dimensional hole (e.g., at its inlet or at its outlet) and a two-dimensional hole defined by the inner surface of the catheter. See also the two-dimensional hole of the structure shown in Figure 3K , which is defined by the surface as shown.

[0414] 4.5 Other Notes

[0415] A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.

[0416] ​Unless otherwise stated in the context, and where a range of values is provided, it is to be understood that each intervening value, to the tenth of the unit of the lower limit, and any other stated or intervening value in that stated range is encompassed within the present technology. The upper and lower limits of these intervening ranges can independently be included in the smaller ranges, and are also encompassed within the technology, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the technology.

[0417] Further, where any of the one or more values of the present technology are implemented to be a part of the present technology as part of the present technology, it is to be understood that such values can be approximate unless otherwise specified, and that the values can be implemented to the degree of precision permitted or required by the technology implementing the same.

[0418] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this technology belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present technology, a limited number of the exemplary methods and materials are described herein.

[0419] Where a particular material is identified as being useful for configuring a component, obvious alternative materials with similar properties are a substitute therefor. Further, unless specified to the contrary, any and all components herein are understood to be capable of being manufactured and thus can be manufactured together or separately.

[0420] It must be noted that, as used herein and in the appended claims, the singular form "a", "an", and "the" include plural references unless the context clearly dictates otherwise.

[0421] All publications mentioned herein are incorporated by reference to disclose and describe the methods and / or materials in connection with which the publications are cited. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present technology is not entitled to antedate such publication by virtue of prior application. Further, the dates of publication provided can be different from the dates that can appear on the publications that were published by the U.S. Patent and Trademark Office.

[0422] The terms "comprises" and "comprising" should be interpreted as not excluding the presence of other elements, components, or steps that are not expressly mentioned.

[0423] The main headings used in the detailed description are included for ease of reference only and shall not be construed as limiting the subject matter found in the entire disclosure or in the claims. The subject headings shall not be used to construe the scope of the claims or the claims limitations.

[0424] While the present technology has been described with reference to specific examples, it will be appreciated that various modifications can be made to the described examples, and that the present technology can be practiced without using all the features and benefits fixed only on the particular embodiments described herein. For example, although terminology from the field of medical devices and procedures has been used to describe the present technology, the present technology has application in other fields. One of ordinary skill in the art will recognize other permutations, combinations, and the like. For example, although the terms "first" and "second" can be used, they are not intended to denote any order, unless otherwise specified, but are used to distinguish one element from another. Additionally, although process steps within a method can be described or illustrated in a particular order, this order is not required. One skilled in the art will recognize that the order of steps can be modified, and / or other steps can be added, removed, or combined.

[0425] Thus, it is to be understood that numerous modifications can be made to the illustrative examples and that other arrangements can be devised without departing from the spirit and scope of the present technology.

[0426] 4.6 List of Reference Numerals

[0427] 1000 Patient

[0428] 1100 Bed Partner

[0429] 3000 Patient Interface

[0430] 3100 Seal-forming Structure

[0431] 3200 Plenum Chamber

[0432] 3300 Structure

[0433] 3400 Breather Port

[0434] 3402 Passage

[0435] 3404 Wall

[0436] 3406 Diffusing Material

[0437] 3408 Housing

[0438] 3410 Air Passage

[0439] 3412 Gap

[0440] 3412A Second Portion

[0441] 3414 Surface

[0442] 3416 Opening

[0443] 3418 portion

[0444] 3420 opening

[0445] 3422 arrow

[0446] 3424 opening

[0447] 3426 feature

[0448] 3428 wall

[0449] 3430 centreline

[0450] 3432 centreline

[0451] 3434 support

[0452] 3436 side surface

[0453] 3438 recess

[0454] 3440 cover

[0455] 3442 deflector

[0456] 3600 connection port

[0457] 3700 forehead support

[0458] 4000 RPT device

[0459] 4170 air circuit

[0460] 5000 humidifier.

Claims

1. A gas flushing vent for a patient interface system, configured to maintain a treatment pressure within a range of 4 cmH2O to 30 cmH2O above ambient pressure during use throughout the patient's respiratory cycle, while the patient is asleep, to improve respiratory or sleep-disordered breathing, said gas flushing vent comprising: A housing comprising a cylindrical wall having one or more channels extending through the cylindrical wall, the one or more channels being configured to provide fluid communication with a portion of the patient interface system configured to be exposed to the therapeutic pressure. Each of the one or more channels includes a corresponding first opening on a first surface of the cylindrical wall, and the housing at least partially forms a second opening communicating with the ambient atmosphere; as well as A diffuse material, at least partially located within the housing adjacent to the first surface, the surface of the diffuse material facing the first surface being spaced apart from the first surface by a gap extending to provide fluid communication between all the first openings and between all the first openings and the second opening; The diffuser material includes a side surface that is transverse to the surface of the diffuser material facing the first surface, and the diffuser material is at least partially located within the housing such that a portion of the housing includes a wall configuration configured to at least partially surround the side surface. The size of at least one of the one or more channels is configured such that when a portion of the patient interface system is exposed to the treatment pressure, at least a portion of the air exiting the corresponding first opening permeates into the diffuse material. The gas flushing vent is configured such that a portion of the air exiting the corresponding first opening permeates through the surface and exits the diffuser material. The housing is configured to prevent air from escaping from the housing in all areas directly opposite each of the first openings. The diffuser material and the cylindrical wall material are different materials.

2. The gas flushing vent according to claim 1, wherein the cylindrical wall forms a central airway, the central airway forms part of an inlet, the inlet being configured to provide a positive-pressure air supply to a portion of the patient interface system configured to be exposed to the treatment pressure.

3. The gas flushing vent according to claim 1, wherein the one or more channels are arranged in a ring along the cylindrical wall to radially separate the air flowing out of the one or more channels.

4. The gas flushing vent according to claim 1, wherein the second opening is provided only at one end of the diffuse material.

5. The gas flushing vent according to claim 1, wherein the second opening is disposed at each of the two ends of the diffuse material.

6. The gas flushing vent of claim 1, wherein the gas flushing vent is configured such that a portion of the air that has permeated into the diffuser material leaves the diffuser material and re-enters the gap before flowing out from the second opening.

7. The gas flushing vent according to any one of claims 1 to 6, wherein when air leaves the second opening, noise of no more than 28 dB(A) is generated due to the portion of the patient interface being exposed to the treatment pressure.

8. The gas flushing vent according to any one of claims 1 to 6, wherein the diffuser material comprises uncompressed fibers.

9. The gas flushing vent according to any one of claims 1 to 6, wherein the diffuser material comprises a moisture-absorbing material.

10. The gas flushing vent according to claim 9, wherein the moisture-absorbing material is sintered plastic.

11. The gas flushing vent according to any one of claims 1 to 6, wherein the diffuser material comprises a hydrophobic material.

12. The gas flushing vent according to any one of claims 1 to 6, wherein the diffuser material has antibacterial properties.

13. The gas flushing vent according to any one of claims 1 to 6, wherein the cylindrical wall is fixed within the housing in a non-releasable manner.

14. The gas flushing vent according to any one of claims 1 to 6, wherein the gap is at least partially defined by the cylindrical wall from the first opening to the second opening.

15. The gas flushing vent of claim 14, wherein the gap is formed by the surface of the diffuse material from a position opposite to the first opening to the portion of the second opening closest to the first opening.

16. The gas flushing vent according to any one of claims 1 to 6, wherein the gap narrows in the radial direction.

17. The gas flushing vent according to any one of claims 1 to 6, wherein the surface of the diffuser material is parallel to the first surface.

18. The gas flushing vent according to any one of claims 1 to 6, wherein a portion of the housing is removable to allow replacement of the diffuser material.

19. The gas flushing vent according to any one of claims 1 to 6, wherein the dimensions of the second opening and the gap are configured such that during air flow through the channel, the gap and the second opening, most of the pressure decreases before the air leaves the channel.

20. The gas flushing vent according to any one of claims 1 to 6, wherein the gas flushing vent includes a separate device for engaging with a patient interface or air circuit.

21. The gas flushing vent according to any one of claims 1 to 6, wherein the second opening faces the side surface of the diffuse material.

22. The gas flushing vent according to any one of claims 1 to 6, wherein, A portion of the housing includes a wall configuration configured to surround the diffuse material and prevent air from flowing out of the housing in all areas directly opposite each of the one or more channels.

23. The gas flushing vent according to any one of claims 1 to 6, wherein the flow path through the second opening is substantially perpendicular to the one or more channels.

24. A gas flushing vent for a patient interface system, configured to maintain a treatment pressure within a range of 4 cmH2O to 30 cmH2O above ambient pressure during use throughout the patient's respiratory cycle, while the patient is asleep, to improve respiratory or sleep-disordered breathing, said gas flushing vent comprising: A cylindrical wall forms an air passage along the cylindrical axis of the cylindrical wall, and the gas flushing and ventilation port has an integral annular structure, so that the gas leaving the gas flushing and ventilation port is discharged along the cylindrical axis. One or more channels passing through the cylindrical wall, the one or more channels being configured to provide fluid communication with a patient interface system configured to be exposed to a portion of the therapeutic pressure, the one or more channels communicating with and arranging around the airway, each of the one or more channels including a corresponding first opening on a first surface of the cylindrical wall; An annular shell surrounding the cylindrical wall, the annular shell at least partially forming a second opening communicating with the ambient atmosphere; and A diffuse material, which is at least partially located within the annular housing adjacent to the first surface, wherein the surface of the diffuse material facing the first surface is spaced apart from the first surface by a gap that extends to provide fluid communication between all the first openings and the second opening; The diffuser material includes a side surface that is transverse to the surface of the diffuser material facing the first surface, and the diffuser material is at least partially located within the annular housing such that a portion of the annular housing includes a wall configuration configured to at least partially surround the side surface. The size of at least one of the one or more channels is configured such that when a portion of the patient interface system is exposed to the treatment pressure, at least a portion of the air exiting the corresponding first opening permeates into the diffuse material. The gas flushing vent is configured such that a portion of the air exiting the corresponding first opening permeates through the surface and exits the diffuser material. The annular housing is configured to prevent air from flowing out of the annular housing in all areas directly opposite each of the first openings; The diffuser material is different from the material of the cylindrical wall, and The diffuse material and the annular shell are different materials.

25. The gas flushing vent according to claim 24, wherein the second opening is disposed at both ends of the diffuse material relative to the cylindrical axis.

26. The gas flushing vent according to claim 24, wherein the second opening is provided only at one end of the diffuse material relative to the cylindrical axis.

27. A patient interface for treating a patient’s respiratory distress, the patient interface comprising a gas flushing vent according to any one of claims 1 to 26.

28. A system for treating respiratory disturbances in a patient, comprising: Respiratory pressure therapy device; humidifier; Air circuit; as well as Patient interface At least one of the air circuit and the patient interface includes a gas flushing vent according to any one of claims 1 to 26.

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