Breathable gas flow-generators with sound abatement device

Abstract

The technology relates an apparatus for gas flow generation comprising a housing having an inlet and an outlet, a blower comprising a motor and an impeller to draw ambient gases into the housing through the inlet and out of the housing through the outlet, and at least one sound abatement device lining one or more surfaces of the housing and / or blower. Also disclosed is a sound abatement device comprising a nonwoven textile configured to absorb sound waves for reducing noise in an apparatus for supplying a flow of breathable gas at a positive pressure for respiratory therapy.

Description

BREATHABLE GAS FLOW-GENERATORS WITH SOUND ABATEMENT DEVICE1 BACKGROUND OF THE TECHNOLOGY1.1 FIELD OF THE TECHNOLOGY

[0001] The present technology relates to one or more of the screening, diagnosis, monitoring, treatment, prevention and amelioration of respiratory-related disorders.

[0002] The present technology also relates to medical or household devices or apparatus, and their use.1.2 DESCRIPTION OF THE RELATED ART1.2.1 Human Respiratory System and its Disorders

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

[0004] The airways include a series of branching tubes, which become narrower, shorter and more numerous as they penetrate deeper into the lung. The prime function of the lung is gas exchange, allowing oxygen to move from the inhaled air into the venous blood and carbon dioxide to move in the opposite direction. The trachea divides into right and left main bronchi, which further divide eventually into terminal bronchioles. The bronchi make up the conducting airways, and do not take part in gas exchange. Further divisions of the airways lead to the respiratory bronchioles, and eventually to the alveoli. The alveolated region of the lung is where the gas exchange takes place, and is referred to as the respiratory zone. See “ Respiratory Physiology” , by John B. West, Lippincott Williams & Wilkins, 9th edition published 2012.

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

[0006] Examples of respiratory disorders include Obstructive Sleep Apnea (OSA), Cheyne-Stokes Respiration (CSR), respiratory insufficiency, Obesity Hypoventilation Syndrome (OHS), Chronic Obstructive Pulmonary Disease (COPD), Neuromuscular Disease (NMD) and Chest wall disorders.

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

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

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

[0010] A patient with respiratory insufficiency (a form of respiratory failure) may experience abnormal shortness of breath on exercise.

[0011] Obesity Hypoventilation Syndrome (OHS) is defined as the combination of severe obesity and awake chronic hypercapnia, in the absence of other known causes for hypoventilation. Symptoms include dyspnea, morning headache and excessive daytime sleepiness.

[0012] 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, extended expiratory phase of respiration, and loss of the normal elasticity of the lung. Examples of COPD are emphysema and chronic bronchitis. COPD is caused by chronic tobacco smoking (primary risk factor), occupational exposures, air pollution and genetic factors. Symptoms include: dyspnea on exertion, chronic cough and sputum production.

[0013] Neuromuscular Disease (NMD) is a broad term that encompasses many diseases and ailments that impair the functioning of the muscles either directly via intrinsic muscle pathology, or indirectly via nerve pathology. Some NMD patients arecharacterised by progressive muscular impairment leading to loss of ambulation, being wheelchair-bound, swallowing difficulties, respiratory muscle weakness and, eventually, death from respiratory failure. Neuromuscular disorders can be divided into rapidly progressive and slowly progressive: (i) Rapidly progressive disorders: Characterised by muscle impairment that worsens over months and results in death within a few years (e.g. Amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers); (ii) Variable or slowly progressive disorders: Characterised by muscle impairment that worsens over years and only mildly reduces life expectancy (e.g. Limb girdle, Facioscapulohumeral and Myotonic muscular dystrophy). Symptoms of respiratory failure in NMD include: increasing generalised weakness, dysphagia, dyspnea on exertion and at rest, fatigue, sleepiness, morning headache, and difficulties with concentration and mood changes.

[0014] Chest wall disorders are a group of thoracic deformities that result in inefficient coupling between the respiratory muscles and the thoracic cage. The disorders are usually characterised by a restrictive defect and share the potential of long term hypercapnic respiratory failure. Scoliosis and / or kyphoscoliosis may cause severe respiratory failure. Symptoms of respiratory failure include: dyspnea on exertion, peripheral oedema, orthopnea, repeated chest infections, morning headaches, fatigue, poor sleep quality and loss of appetite.

[0015] A range of therapies have been used to treat or ameliorate such conditions. Furthermore, otherwise healthy individuals may take advantage of such therapies to prevent respiratory disorders from arising. However, these have a number of shortcomings.1.2.2 Therapies

[0016] Various respiratory therapies, such as Continuous Positive Airway Pressure (CPAP) therapy, Non-invasive ventilation (NIV), Invasive ventilation (IV), and High Flow Therapy (HFT) have been used to treat one or more of the above respiratory disorders.1.2.2.1 Respiratory pressure therapies

[0017] Respiratory pressure therapy is the application of a supply of air to an entrance to the airways at a controlled target pressure that is nominally positive with respect to atmosphere throughout the patient’s breathing cycle (in contrast to negative pressure therapies such as the tank ventilator or cuirass).

[0018] Continuous Positive Airway Pressure (CPAP) therapy has been used to treat Obstructive Sleep Apnea (OSA). The mechanism of action is that continuous positive airway pressure acts as a pneumatic splint and may prevent upper airway occlusion, such as by pushing the soft palate and tongue forward and away from the posterior oropharyngeal wall. Treatment of OSA by CPAP therapy may be voluntary, and hence patients may elect not to comply with therapy if they find devices used to provide such therapy one or more of: uncomfortable, difficult to use, expensive and aesthetically unappealing.

[0019] Non-invasive ventilation (NIV) provides ventilatory support to a patient through the upper airways to assist the patient breathing and / or maintain adequate oxygen levels in the body by doing some or all of the work of breathing. The ventilatory support is provided via a non-invasive patient interface. NIV has been used to treat CSR and respiratory failure, in forms such as OHS, COPD, NMD and Chest Wall disorders. In some forms, the comfort and effectiveness of these therapies may be improved.

[0020] Invasive ventilation (IV) provides ventilatory support to patients that are no longer able to effectively breathe themselves and may be provided using a tracheostomy tube or endotracheal tube. In some forms, the comfort and effectiveness of these therapies may be improved.1.2.2.2 Flow therapies

[0021] Not all respiratory therapies aim to deliver a prescribed therapeutic pressure. Some respiratory therapies aim to deliver a prescribed respiratory volume, by delivering an inspiratory flow rate profile over a targeted duration, possibly superimposed on a positive baseline pressure. In other cases, the interface to the patient’s airways is ‘open’ (unsealed) and the respiratory therapy may only supplement the patient’s own spontaneous breathing with a flow of conditioned or enriched gas. In one example, High Flow therapy (HFT) is the provision of a continuous, heated, humidified flow of air to an entrance to the airway through an unsealed or open patient interface at a “treatment flow rate” that may be held approximately constant throughout the respiratory cycle. The treatment flow rate is nominally set to exceed the patient’s peak inspiratory flow rate. HFT has been used to treat OSA, CSR, respiratory failure, COPD, and other respiratory disorders. One mechanism of action is that the high flow rate of air at the airway entrance improves ventilation efficiency by flushing, or washing out, expired CO2 from the patient’sanatomical deadspace. Hence, HFT is thus sometimes referred to as a deadspace therapy (DST). Other benefits may include the elevated warmth and humidification (possibly of benefit in secretion management) and the potential for modest elevation of airway pressures. As an alternative to constant flow rate, the treatment flow rate may follow a profile that varies over the respiratory cycle.

[0022] Another form of flow therapy is long-term oxygen therapy (LTOT) or supplemental oxygen therapy. Doctors may prescribe a continuous flow of oxygen enriched air at a specified oxygen concentration (from 21%, the oxygen fraction in ambient air, to 100%) at a specified flow rate (e.g., 1 litre per minute (LPM), 2 LPM, 3 LPM, etc.) to be delivered to the patient’s airway.1.2.3 Respiratory Therapy Systems

[0023] These respiratory therapies may be provided by a respiratory therapy system or device. Such systems and devices may also be used to screen, diagnose, or monitor a condition without treating it.

[0024] A respiratory therapy system may comprise a Respiratory Pressure Therapy Device (RPT device), an air circuit, a humidifier, a patient interface, an oxygen source, and data management.1.2.3.1 Patient Interface

[0025] A patient interface may be used to interface respiratory equipment to its wearer, for example by providing a flow of air to an entrance to the airways. The flow of air may be provided via a mask to the nose and / or mouth, a tube to the mouth or a tracheostomy tube to the trachea of a patient. Depending upon the therapy to be applied, the patient interface may form a seal, e.g., with a region of the patient's face, to facilitate the delivery of gas at a pressure at sufficient variance with ambient pressure to effect therapy, e.g., at a positive pressure of about 10 cmH20 relative to ambient pressure. For other forms of therapy, such as the delivery of oxygen, the patient interface may not include a seal sufficient to facilitate delivery to the airways of a supply of gas at a positive pressure of about 10 cmH20. For flow therapies such as nasal HFT, the patient interface is configured to insufflate the nares but specifically to avoid a complete seal. One example of such a patient interface is a nasal cannula.1.2.3.2 Respiratory Pressure Therapy (RPT) Device

[0026] A respiratory pressure therapy (RPT) device may be used individually or as part of a system to deliver one or more of a number of therapies described above, such as by operating the device to generate a flow of air for delivery to an interface to the airways. The flow of air may be pressure-controlled (for respiratory pressure therapies) or flow-controlled (for flow therapies such as HFT). Thus RPT devices may also act as flow therapy devices. Examples of RPT devices include a CPAP device and a ventilator.

[0027] Air pressure generators are known in a range of applications, e.g. industrial-scale ventilation systems. However, air pressure generators for medical applications have particular requirements not fulfilled by more generalised air pressure generators, such as the reliability, size and weight requirements of medical devices. In addition, even devices designed for medical treatment may suffer from shortcomings, pertaining to one or more of: comfort, noise, ease of use, efficacy, size, weight, manufacturability, cost, and reliability.

[0028] An example of the special requirements of certain RPT devices is acoustic noise.

[0029] Table of noise output levels of prior RPT devices (one specimen only, measured using test method specified in ISO 3744 in CPAP mode at 10 cmH20).

[0030] One known RPT device used for treating sleep disordered breathing is the S9 Sleep Therapy System, manufactured by ResMed Inc. Another example of an RPT device is a ventilator. Ventilators such as the ResMed Stellar™ Series of Adult and Paediatric Ventilators may provide support for invasive and non-invasive non-dependent ventilation for a range of patients for treating a number of conditions such as but not limited to NMD, OHS and COPD.

[0031] The ResMed Elisee™ 150 ventilator and ResMed VS III™ ventilator may provide support for invasive and non-invasive dependent ventilation suitable for adult or paediatric patients for treating a number of conditions. These ventilators provide volumetric and barometric ventilation modes with a single or double limb circuit.RPT devices typically comprise a pressure generator, such as a motor-driven blower or a compressed gas reservoir, and are configured to supply a flow of air to the airway of a patient. In some cases, the flow of air may be supplied to the airway of the patient at positive pressure. The outlet of the RPT device is connected via an air circuit to a patient interface such as those described above.

[0032] Some known RPT devices use foam components at various locations within an RPT device to reduce noise while the RPT system is in use. Due to the manufacturing methods required to produce foam, there can be inconsistency in the structure and composition of the foam. This leads to difficulties in assembly.

[0033] The flexible nature of a foam component also results in restrictions as to the strength and shape-ability of any components formed from foam materials.

[0034] The designer of a device may be presented with an infinite number of choices to make. Design criteria often conflict, meaning that certain design choices are far from routine or inevitable. Furthermore, the comfort and efficacy of certain aspects may be highly sensitive to small, subtle changes in one or more parameters.1.2.3.3 Air circuit

[0035] An air circuit is a conduit or a tube constructed and arranged to allow, in use, a flow of air to travel between two components of a respiratory therapy system such as the RPT device and the patient interface. In some cases, there may be separate limbs of the air circuit for inhalation and exhalation. In other cases, a single limb air circuit is used for both inhalation and exhalation.1.2.3.4 Humidifier

[0036] Delivery of a flow of air without humidification may cause drying of airways. The use of a humidifier with an RPT device and the patient interface produces humidified gas that minimizes drying of the nasal mucosa and increases patient airway comfort. In addition, in cooler climates, warm air applied generally to the face area in and about the patient interface is more comfortable than cold air.1.2.3.5 Data Management

[0037] There may be clinical reasons to obtain data to determine whether the patient prescribed with respiratory therapy has been “compliant”, e.g. that the patient has used their RPT device according to one or more “compliance rules”. One example of a compliance rule for CPAP therapy is that a patient, in order to be deemed compliant, is required to use the RPT device for at least four hours a night for at least 21 of 30 consecutive days. In order to determine a patient's compliance, a provider of the RPT device, such as a health care provider, may manually obtain data describing the patient's therapy using the RPT device, calculate the usage over a predetermined time period, and compare with the compliance rule. Once the health care provider has determined that the patient has used their RPT device according to the compliance rule, the health care provider may notify a third party that the patient is compliant.

[0038] There may be other aspects of a patient’s therapy that would benefit from communication of therapy data to a third party or external system.

[0039] Existing processes to communicate and manage such data can be one or more of costly, time-consuming, and error-prone.2 BRIEF SUMMARY OF THE TECHNOLOGY

[0040] The present technology is directed towards providing gas flow generation apparatus, including a sound abatement device that results in one or more of improved auditory characteristics, ease of manufacturability, cost or efficacy of the apparatus.

[0041] The present technology is also directed towards providing medical devices used in the screening, diagnosis, monitoring, amelioration, treatment, or prevention of respiratory disorders having one or more of improved comfort, cost, efficacy, ease of use and manufacturability.

[0042] A first aspect of the present technology relates to gas flow generation apparatus having improved noise reduction capabilities.

[0043] Another aspect relates to sound abatement devices suitable for use in apparatus for gas flow generation.

[0044] Another aspect of the present technology relates to apparatus used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respiratory disorder.

[0045] Another aspect of the present technology relates to methods used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respiratory disorder.

[0046] An aspect of certain forms of the present technology is to provide methods and / or apparatus that improve the compliance of patients with respiratory therapy.

[0047] One form of the present technology comprises a positioning and stabilising structure configured to provide a force to hold a seal-forming structure in a therapeutically effective position on the patient’s head. The positioning and stabilising structure includes at least one strap.

[0048] One form of the present technology comprises a patient interface comprising a plenum chamber, a seal-forming structure, and a positioning and stabilising structure.

[0049] One form of the present technology comprises patient interface comprising a plenum chamber pressurisable to a therapeutic pressure of at least 4 cmH20 above ambient air pressure. The plenum chamber includes at least one plenum chamber inlet port sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient. The patient interface also comprises a seal-forming structure that is constructed and arranged to form a seal with a region of the patient’s face surrounding an entrance to the patient’s airways. The seal-forming structure has a hole therein such that the flow of air at said therapeutic pressure is delivered to at least an entrance to the patient’s nares. The seal-forming structure is constructed and arranged to maintain said therapeutic pressure in the plenum chamber throughout the patient’s respiratory cycle in use. The patient interface also comprises a positioning and stabilising structure to provide a force to hold the seal-forming structure in a therapeutically effective position on the patient’s head.

[0050] One form of the present technology comprises a flow generation apparatus for generating a flow of breathable gas at a positive pressure for respiratory therapy comprising: a housing having an inlet and an outlet; a blower comprising a motor and an impeller to draw ambient gases into the housing through the inlet and out of the housing through the outlet; and at least one nonwoven textile lining or partially lining one or more internal surfaces of or within the housing.

[0051] One form of the present technology comprises a flow generation apparatus for generating a flow of breathable gas at a positive pressure for respiratory therapy comprising: a housing having an inlet and an outlet; a blower comprising a motor and an impeller to draw ambient gases into the housing through the inlet and out of the housing through the outlet; and at least one sound abatement device comprising a synthetic nonwoven textile, the sound abatement device lining or partially lining one or more internal surfaces of or within the housing.

[0052] A further form of the technology comprises a sound abatement device suitable for use in a gas flow generation apparatus. In some examples, the sound abatement device comprises a nonwoven textile, and in some examples, a synthetic nonwoven textile.

[0053] A further form of the present technology comprises a sound abatement device comprising a nonwoven textile configured to absorb and / or deflect sound waves inside a housing of an apparatus for supplying a flow of breathable gas at a positive pressure for respiratory therapy. In one example, the nonwoven textile is a synthetic nonwoven textile.

[0054] In further examples, the sound abatement device is formed entirely of synthetic materials or a single synthetic material.

[0055] In further examples the sound abatement device or nonwoven textile fully or partially lines one more outer surfaces of the motor.

[0056] In further examples the housing comprises multiple chambers, one or more of the chambers comprising at least one sound abatement device.

[0057] In further examples, the housing comprises multiple chambers, at least one of the chambers comprising at least one sound abatement device.

[0058] In further examples, the apparatus is configured to define a gas flow path between the inlet and outlet of the housing, and the sound abatement device is positioned at least partially within the gas flow path.

[0059] In further examples, an internal surface of the housing comprises one or more flanges, recesses, apertures, channels, notches or hooks configured to receive the at least one sound abatement device.

[0060] In further examples, the nonwoven textile of the sound abatement device is configured to comprise at least two opposing outer surfaces, the two opposing outer surfaces spaced apart and connected by at least one side wall.

[0061] In further examples, the nonwoven textile of the sound abatement device is configured to be curved in shape around an axis parallel to one outer surface of the synthetic nonwoven textile.

[0062] In further examples, the nonwoven textile of the sound abatement device is configured to be curved in shape around an axis perpendicular to a surface of the synthetic nonwoven textile.

[0063] In further examples, the sound abatement device comprises at least one integrally formed flange, recess, aperture, channel, notch, hook or adhesive configured to enable connection of the sound abatement device to an internal surface of the housing of the apparatus.

[0064] In further examples, the sound abatement device comprises at least one connection member incorporated within or attached to the nonwoven textile. In some examples, the connection member may be one half of a male-female connection member, with the opposing half of the connection member attached to or incorporated within the housing of the apparatus.

[0065] In further examples, the sound abatement device is molded or partially molded directly into or onto an internal wall of the housing of the apparatus.

[0066] In further examples, the sound abatement device is encapsulated or partially encapsulated by a frame portion.

[0067] In further examples, the frame portion is an overmolded edging.

[0068] In further examples, the frame portion comprises a porous scaffold.

[0069] In further examples, the frame portion comprises a front panel of porous scaffold and an opposing back panel of porous scaffold, the front and back panels of porous scaffold connected and spaced apart by at least one side wall, the nonwoven textile located between the front panel and back panel of the porous scaffold, a perimeter of the nonwoven textile surrounded by the at least one side wall of the frame portion.

[0070] In further examples, the porous scaffold is configured to define apertures in the scaffold having a cross-sectional area of 4mm2- 10000mm2, when the crosssection is measured substantially parallel to the nonwoven-textile.

[0071] In further examples, the frame portion comprises at least one retention feature configured to releasably retain the sound abatement device within the housing.

[0072] In further examples, the sound abatement device is formed from a single material. In further examples, the frame portion and the nonwoven textile are formed from the same material. In some examples the frame portion and the nonwoven textile are formed from polypropylene.

[0073] In further examples, the nonwoven textile is a needle-punched nonwoven textile, melt-blown nonwoven textile, spunbond nonwoven textile, spunlace nonwoven textile and / or flashspun nonwoven textile.

[0074] In further examples, the nonwoven textile is formed using thermal bonding, hydroentanglement, ultrasonic pattern bonding, needle-punching and / or chemical bonding.

[0075] In further examples, the nonwoven textile of the sound abatement device comprises at least one treated surface to reduce fibre migration from the nonwoven textile.

[0076] In further examples, the nonwoven textile includes two opposing treated surfaces.

[0077] In further examples, the surfaces are thermally and / or mechanically treated.

[0078] In further examples, the thermally treated surface is formed by glazing the at least one surface of the nonwoven textile at 120 - 170°C.

[0079] In further examples, the nonwoven textile comprises a scrim layer on at least one surface of the nonwoven textile. In some forms, the scrim layer is formed from a nonwoven textile. In some forms the scrim layer is formed from a spun-bond nonwoven.

[0080] In further examples, the scrim coating is bonded to the nonwoven textile using thermal adhesion, mechanical adhesion and / or using an adhesive.

[0081] In further examples, the nonwoven textile comprises two opposing outer surfaces, the two opposing outer surfaces having a different surface texture, surface roughness or contour from each other.

[0082] In further examples, the nonwoven textile has a fibre denier (D) of 3 - 15.

[0083] In further examples, the nonwoven textile has a density of 50 - 200kg / m3.

[0084] In further examples, wherein the porosity of the nonwoven textile is between 50% - 90%.

[0085] In further examples, the housing comprises multiple chambers, at least one of the chambers comprising at least one sound abatement device.

[0086] In further examples, the housing comprises multiple chambers, at least one of the chambers comprising at least one sound abatement device positioned within the same chamber as a flow element.

[0087] In further examples, the apparatus is configured to define a gas flow path between the inlet and outlet of the housing, and the sound abatement device is positioned at least partially within the gas flow path.

[0088] In further examples, the nonwoven textile is formed from one or more sheets or pieces of nonwoven textile between 1 - 20mm thick.

[0089] In further examples the synthetic nonwoven textile is polypropylene or polyethylene terephthalate (PET).

[0090] In further examples the nonwoven textile is formed from hollow fibres.

[0091] In further examples the nonwoven textile has a tensile strength of 20 kN / m - lOOkN / m

[0092] In further examples the nonwoven textile has a mass per unit area of 200 - 1200g / m2.

[0093] In further examples the nonwoven textile has a sound absorption coefficient of 0.4 - 0.95 for sound in the 1 - 6kHz range.

[0094] In further examples the nonwoven textile is positioned within the housing such that the nonwoven textile absorbs sound waves as gas passes adjacent or at an angle to the nonwoven textile as it moves through the housing.

[0095] In further examples the sound abatement device includes integrally formed flanges, recesses, apertures, channels, notches or hooks configured to enable connection of the sound abatement device to a / the housing of the apparatus.

[0096] In further examples the sound abatement device is configured to be slidably receivable by a / the housing of the apparatus.

[0097] In further examples the device comprises multiple layers of connected nonwoven textile.

[0098] In further examples the nonwoven textile includes multiple layers of differently sized nonwoven textile laminated together to form an irregularly shaped sound abatement device.

[0099] In further examples the device comprises one or more areas of shaped, moulded or textured outer surface to increase the surface area of the sound abatement device.

[0100] In further examples the sound abatement device is shaped to correspond to an internal surface of a / the housing.

[0101] In further examples the nonwoven textile is shaped via thermoforming.

[0102] In further examples the nonwoven textile is inelastic.

[0103] Another aspect of one form of the present technology is a patient interface that is moulded or otherwise constructed with a perimeter shape which is complementary to that of an intended wearer.

[0104] An aspect of one form of the present technology is a method of manufacturing apparatus.

[0105] Another aspect of one form of the present technology is a method of assembling a modular system comprising selecting a positioning and stabilising structure, and connecting the positioning and stabilising structure to either a first cushion or a second cushion.

[0106] An aspect of certain forms of the present technology is a medical device that is easy to use, e.g. by a person who does not have medical training, by a person who has limited dexterity, vision or by a person with limited experience in using this type of medical device.

[0107] An aspect of one form of the present technology is a portable RPT device that may be carried by a person, e.g., around the home of the person.

[0108] An aspect of one form of the present technology is a patient interface that may be washed in a home of a patient, e.g., in soapy water, without requiring specialised cleaning equipment. An aspect of one form of the present technology is a humidifier tank that may be washed in a home of a patient, e.g., in soapy water, without requiring specialised cleaning equipment.

[0109] The methods, systems, devices and apparatus described may be implemented so as to improve the functionality of a processor, such as a processor of a specific purpose computer, respiratory monitor and / or a respiratory therapy apparatus. Moreover, the described methods, systems, devices and apparatus can provide improvements in the technological field of automated management, monitoring and / or treatment of respiratory conditions, including, for example, sleep disordered breathing.

[0110] Of course, portions of the aspects may form sub-aspects of the present technology. Also, various ones of the sub-aspects and / or aspects may be combined in various manners and also constitute additional aspects or sub-aspects of the present technology.

[0111] Other features of the technology will be apparent from consideration of the information contained in the following detailed description, abstract, drawings and claims.3 BRIEF DESCRIPTION OF THE DRAWINGS

[0112] The present technology is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which like reference numerals refer to similar elements including:3.1 RESPIRATORY THERAPY SYSTEMSFig. 1A shows a system including a patient 1000 wearing a patient interface 3000, in the form of nasal pillows, receiving a supply of air at positive pressure from a respiratory therapy (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.Fig. IB shows a system including a patient 1000 wearing a patient interface 3000, in the form of a nasal mask, receiving a supply of air at positive pressure from an RPT device 4000. Air from the RPT device is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000.Fig. 1C shows a system including a patient 1000 wearing a patient interface 3000, in the form of a full-face mask, receiving a supply of air at positive pressure from an RPT device 4000. Air from the RPT device is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000. The patient is sleeping in a side sleeping position.Fig. 2A shows an overview of a human respiratory system including the nasal and oral cavities, the larynx, vocal folds, oesophagus, trachea, bronchus, lung, alveolar sacs, heart and diaphragm.Fig. 3A shows a patient interface in the form of a nasal mask in accordance with one form of the present technology.Fig. 4A shows an RPT device in accordance with one form of the present technology.Fig. 4B is a schematic diagram of the pneumatic path of an RPT device in accordance with one form of the present technology. The directions of upstream and downstream are indicated with reference to the blower and the patient interface. The blower is defined to be upstream of the patient interface and the patient interface is defined to be downstream of the blower, regardless of the actual flow direction at any particular moment. Items which are located within the pneumatic path between the blower and the patient interface are downstream of the blower and upstream of the patient interface.Fig. 4C is a schematic diagram of the electrical components of an RPT device in accordance with one form of the present technology.Fig. 4D shows a partial housing of a pneumatic block of a gas-flow generation apparatus including a sound abatement device in accordance with one form of the present technology.Fig. 4E shows a sound abatement device formed for lining a region of a housing or blower in a gas-flow generation apparatus in accordance with one form of the technology.Fig. 4F shows a partial housing of a gas-flow generation apparatus comprising multiple sound abatement devices lining the walls of the housing in accordance with one form of the technology.Fig. 4F-1 shows a partial housing of a gas-flow generation apparatus of Fig. 4F, indicating a gas flow path within the housing.Fig. 4G shows an alternative gas-flow generation apparatus, including sound abatement devices adapted for inclusion within the housing of a gas-flow generation apparatus in accordance with one form of the technology.Fig. 4H shows a sound abatement device in accordance with one form of the technology.Fig. 41 shows a cross section of a sound abatement device with an overmolded edge potion in accordance with one form of the technology.Fig. 4J shows a top view of a sound abatement device with an overmolded edge potion in accordance with one form of the technology.Fig. 4K shows the surface of a nonwoven textile prior to surface treatment in accordance with one form of the technology.Fig. 4L shows the surface of a nonwoven textile following surface treatment in accordance with one form of the technology.Fig. 4M shows a microscopic surface view of a region of nonwoven textile following thermal treatment of the nonwoven surface.Fig. 4N shows scrim and nonwoven textile layers of a sound abatement material prior to connection in accordance with one form of the technology.Fig. 5A shows an isometric view of a humidifier in accordance with one form of the present technology.Fig. 5B shows an isometric view of a humidifier in accordance with one form of the present technology, showing a humidifier reservoir 5110 removed from the humidifier reservoir dock 5130.Fig. 6A shows a model typical breath waveform of a person while sleeping.Fig. 7A shows a perspective view of a cushion of a patient interface configured to be worn by a patient and convey pressurized air to the patient’s nose and the patient’s mouth.4 DETAILED DESCRIPTION OF EXAMPLES OF THETECHNOLOGY

[0113] Before the present technology is described in further detail, it is to be understood that the technology is not limited to the particular examples described herein, which may vary. It is also to be understood that the terminology used in this disclosure is for the purpose of describing only the particular examples discussed herein, and is not intended to be limiting.

[0114] The following description is provided in relation to various examples which may share one or more common characteristics and / or features. It is to be understood that one or more features of any one example may be combinable with one or more features of another example or other examples. In addition, any single feature or combination of features in any of the examples may constitute a further example.

[0115] The term denier ( / 'deniar / ) or den (abbreviated D) is used as a unit of measure for the linear mass density of fibers, is the mass in grams per 9,000 metres of the fiber.4.1 THERAPY

[0116] In another form, the present technology comprises a method for treating a respiratory disorder comprising applying positive pressure to the entrance of the airways of a patient 1000.

[0117] In certain examples of the present technology, a supply of air at positive pressure is provided to the nasal passages of the patient via one or both nares.

[0118] In certain examples of the present technology, mouth breathing is limited, restricted or prevented.4.2 RESPIRATORY THERAPY SYSTEMS

[0119] In one form, the present technology comprises a respiratory therapy system for treating a respiratory disorder. The respiratory therapy system may comprise an RPT device 4000 for supplying a flow of air to the patient 1000 via an air circuit 4170 and a patient interface 3000 or 3800.4.3 PATIENT INTERFACE

[0120] A non-invasive patient interface 3000, such as that shown in Fig. 3A, in accordance with one aspect of the present technology comprises the following functional aspects: a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilising structure 3300, a vent 3400, one form of connection port 3600 for connection to air circuit 4170, and a forehead support 3700. In some forms a functional aspect may be provided by one or more physical components. In some forms, one physical component may provide one or more functional aspects. In use the seal-forming structure 3100 is arranged to surround an entrance to the airways of the patient so as to maintain positive pressure at the entrance(s) to the airways of the patient 1000. The sealed patient interface 3000 is therefore suitable for delivery of positive pressure therapy.4.4 RPT DEVICE

[0121] An RPT device 4000 in accordance with one aspect of the present technology comprises mechanical, pneumatic, and / or electrical components and is configured to execute one or more algorithms 4300, such as any of the methods, in whole or in part, described herein. The RPT device 4000 may be configured togenerate a flow of air for delivery to a patient’s airways, such as to treat one or more of the respiratory conditions described elsewhere in the present document.

[0122] In one form, the RPT device 4000 is constructed and arranged to be capable of delivering a flow of air in a range of -20 L / min to +150 L / min while maintaining a positive pressure of at least 4 cmH20, or at least 10cmH2O, or at least 20 cmH20.

[0123] The RPT device may have an external housing 4010, formed in two parts, an upper portion 4012 and a lower portion 4014. Furthermore, the external housing 4010 may include one or more panel(s) 4015. The RPT device 4000 comprises a chassis 4016 that supports one or more internal components of the RPT device 4000. The RPT device 4000 may include a handle 4018.

[0124] The pneumatic path of the RPT device 4000 may comprise one or more air path items, e.g., an inlet air filter 4112, an inlet muffler 4122, a pressure generator 4140 capable of supplying air at positive pressure (e.g., a blower 4142), an outlet muffler 4124 and one or more transducers 4270, such as pressure sensors 4272 and flow rate sensors 4274.

[0125] One or more of the air path items may be located within a removable unitary structure which will be referred to as a pneumatic block 4020. The pneumatic block 4020 may be located within the external housing 4010. In one form a pneumatic block 4020 is supported by, or formed as part of the chassis 4016.

[0126] As shown in Fig. 4C, the RPT device 4000 may have an electrical power supply 4210, one or more input devices 4220, a central controller 4230, a therapy device controller 4240, a pressure generator 4140, one or more protection circuits 4250, memory 4260, transducers 4270, data communication interface 4280 and one or more output devices 4290. Electrical components 4200 may be mounted on a single Printed Circuit Board Assembly (PCBA) 4202. In an alternative form, the RPT device 4000 may include more than one PCBA 4202.4.4.1 RPT device mechanical & pneumatic components

[0127] An RPT device may comprise one or more of the following components in an integral unit. In an alternative form, one or more of the following components may be located as respective separate units.4.4.1.1 Air filter (s)

[0128] An RPT device in accordance with one form of the present technology may include an air filter 4110, or a plurality of air filters 4110.

[0129] In one form illustrated in Fig. 4B, an inlet air filter 4112 is located at the beginning of the pneumatic path upstream of a pressure generator 4140.

[0130] In one form illustrated in Fig. 4B, an outlet air filter 4114, for example an antibacterial filter, is located between an outlet of the pneumatic block 4020 and a patient interface 3000 or 3800.4.4.1.2 Muffler(s)

[0131] An RPT device in accordance with one form of the present technology may include a muffler 4120, or a plurality of mufflers 4120.

[0132] In one form of the present technology (see e.g., Fig. 4B), an inlet muffler 4122 is located in the pneumatic path upstream of a pressure generator 4140.

[0133] In one form of the present technology, an outlet muffler 4124 is located in the pneumatic path between the pressure generator 4140 and a patient interface 3000 or 3800.4.4.1.3 Pressure generator

[0134] In one form of the present technology, a pressure generator 4140 for producing a flow, or a supply, of air at positive pressure is a controllable blower 4142. For example, the blower 4142 may include a brushless DC motor 4144 with one or more impellers. The impellers may be located in a volute. The blower may be capable of delivering a supply of air, for example at a rate of up to about 120 litres / minute, at a positive pressure in a range from about 4 cmH20 to about 20 cmH20, or in other forms up to about 30 cmH20 when delivering respiratory pressure therapy. The blower may be as described in any one of the following patents or patent applications the contents of which are incorporated herein by reference in their entirety: U.S.Patent No. 7,866,944; U.S. Patent No. 8,638,014; U.S. Patent No. 8,636,479; and PCT Patent Application Publication No. WO 2013 / 020167.

[0135] The pressure generator 4140 may be under the control of the therapy device controller 4240.

[0136] In other forms, a pressure generator 4140 may be a piston-driven pump, a pressure regulator connected to a high pressure source (e.g. compressed air reservoir), or a bellows.4.4.1.4 Transducer(s)

[0137] Transducers may be internal of the RPT device, or external of the RPT device. External transducers may be located for example on or form part of the air circuit, e.g., the patient interface. External transducers may be in the form of noncontact sensors such as a Doppler radar movement sensor that transmit or transfer data to the RPT device.

[0138] In one form of the present technology (see e.g., Fig. 4B), one or more transducers 4270 are located upstream and / or downstream of the pressure generator 4140. The one or more transducers 4270 may be constructed and arranged to generate signals representing properties of the flow of air such as a flow rate, a pressure or a temperature at that point in the pneumatic path.

[0139] In one form of the present technology, one or more transducers 4270 may be located proximate to the patient interface 3000 or 3800.

[0140] In one form, a signal from a transducer 4270 may be filtered, such as by low-pass, high-pass or band-pass filtering.4.4.1.4.1 Plow rate sensor

[0141] A flow rate sensor 4274 in accordance with the present technology may be based on a differential pressure transducer, for example, an SDP600 Series differential pressure transducer from SENSIRION.

[0142] In one form, a signal generated by the flow rate sensor 4274 and representing a flow rate is received by the central controller 4230.4.4.1.4.2 Pressure sensor

[0143] A pressure sensor 4272 in accordance with the present technology is located in fluid communication with the pneumatic path. An example of a suitable pressure sensor is a transducer from the HONEYWELL ASDX series. An alternative suitable pressure sensor is a transducer from the NPA Series from GENERAL ELECTRIC.

[0144] In one form, a signal generated by the pressure sensor 4272 and representing a pressure is received by the central controller 4230.4.4.1.4.3 Motor speed transducer

[0145] In one form of the present technology a motor speed transducer 4276 is used to determine a rotational velocity of the motor 4144 and / or the blower 4142. A motor speed signal from the motor speed transducer 4276 may be provided to thetherapy device controller 4240. The motor speed transducer 4276 may, for example, be a speed sensor, such as a Hall effect sensor.4.4.1.5 Anti-spill back valve

[0146] As shown in Fig. 4B, one form of the present technology, an anti-spill back valve 4160 is located between the humidifier 5000 and the pneumatic block 4020. The anti-spill back valve is constructed and arranged to reduce the risk that water will flow upstream from the humidifier 5000, for example to the motor 4144.4.4.2 Flow restrictors

[0147] In many devices, flow restrictors are included in the airflow path. The restrictors facilitate noise reduction and provide a pressure differential for flow and pressure measurements.4.4.3 Sound Abatement Device

[0148] In one form, the present technology comprises the use of a nonwoven textile to create a sound abatement device for reducing noise created in a gas flow generation apparatus. A wide range of apparatus are known that use the generation of a gas / air flow as a key operational component of the apparatus, for example vacuum cleaners, hairdryers, heating and cooling fans, air blow guns and compressed air dusters to name a few. Typically, high volumes of gas / air can be produced through the use of a blower within a housing, with a rotating impeller to create a vacuum. The vacuum forces ambient air into the blower through an inlet, where it is divided by the rotating impeller blades. As the pressure increases within the housing, the volume of the gas stream increases, before being discharged through a housing outlet. This process creates noise as air / gas flows past an object, edges, voids or cavities as it moves through the blower and housing.

[0149] In respiratory therapy devices, sound suppression may be achieved dividing the air path into a series of chambers connected via inertance tubes, ultimately forming an expansion muffler arrangement. Use of a sound abatement device greatly improves the performance of such an arrangement by (a) absorbing sound and (b) dampening the effects of air cavity resonances.

[0150] As devices are made to a smaller scale, gas-flow path sizes decrease, and may become more convoluted, resulting in increased noise created as gas passes through the housing. 1

[0151] The use of a nonwoven textile for sound abatement in an RPT device introduces a number of advantages compared to traditional foam, particularly in smaller devices where decreased space within the flow-generation apparatus both increases the noise created during use and decreases the available space for sound reduction. Nonwoven fabrics of the present technology may be manufactured with greater precision and consistency than foam, with characteristics such as porosity, density, dimensionality, surface texture and contours able to be controlled and consistently replicated during the manufacturing process, reducing waste, providing consistent sound abatement efficacy during mass manufacturing and ensuring constant airflow.

[0152] The use of a single material to form the synthetic nonwoven textile, frame or connection portions, and / or any surface treatments of the sound abatement device allows for creation of a fully -recyclable device, reducing waste following the end of the product life and increasing product sustainability.

[0153] In the present technology the nonwoven textile lines or partially lines one or more regions on the inside surface of the housing of a flow-generation apparatus, or against a surface of another component itself held within and / or surrounded by the housing. This introduces at least one surface to absorb sound waves as gas passes adjacent or at an angle to the nonwoven, or through it. This is opposed to a hard, smooth housing surface reflecting the sound waves, which may lead to increased noise. Nonwoven textiles provide a porous or semi-porous and web-like structure that decreases the amplitude of sound waves as they move through and are absorbed by the nonwoven structure.

[0154] The close proximity of one surface of the nonwoven to the internal surface it is held against results in reduced or no air / gas flow passing entirely through the nonwoven textile. In this respect the nonwoven acts as a sound absorber, rather than a filter. Both air / gas flow and sound waves travelling through the nonwoven textile that penetrate the nonwoven and contact the internal housing wall are deflected back through the nonwoven, further increasing the sound absorption abilities of the nonwoven textile.

[0155] A sound abatement device 4130 is shown in Figs. 4D to 4N, both as an individual component and incorporated within one or more styles of pneumatic block 4020 of a gas generation apparatus in one example of the technology. Pneumatic block 4020 comprises a housing in the form of a hollow chassis 4016, chassis 4016housing within the cavity a pressure generator 4140 for producing a flow, or a supply, of gas at positive pressure, the pressure generator 4140 being a controllable blower 4142. Chassis 4016 comprises an inlet 4017 and outlet 4019. The gas flow path in one example is shown by arrows in Figure 4F-1, whereby gas flows into housing 4016 through inlet 4017 through flow restrictor 4111, around a central chamber 4016C of housing 4016 and through a second flow restrictor 4112, into adjacent chamber 4016D. The gas flow path exits chamber 4016D via aperture 4116 to return to central chamber 4016C, passing through central chamber 4016C to exit via aperture 4117 into chamber 4016E before exiting housing 4016 through outlet 4019. Flow restrictors are provided and / or shaped to facilitate noise reduction and provide a pressure differential for flow and pressure measurements within a housing.

[0156] Nonwoven textile 4130 is shown in a number of locations within chassis 4016 lining the internal surfaces of chambers 4016C, D and E of chassis 4016 in a number of locations.

[0157] As seen in Fig 4D - 4F-1, the housing comprises a cylindrical chassis 4016, with chassis cover 4016A (Fig. 4D) connectable with chassis base 4016B (Fig. 4F) to form chassis 4016. Chassis housing 4016 comprises internal walls defining chambers 4016C, D and E. Multiple sound abatement devices 4130 are mounted within the interior of chassis 4016, lining the internal surfaces 4040. In some regions, sound abatement device 4130 comprises a nonwoven textile 4131 sized to directly correspond to the boundaries of an internal chassis wall defined by the internal components of the pneumatic block. Fig. 4E shows three separate sound abatement devices 4130A formed from nonwoven textile 4131, with the shape of sound abatement devices 4130A being thermoformed such that the sound abatement devices 4130A are held in a curved form to mimic the shape of the internal housing wall they are designed to be received against. In the example shown, chamber 4016E is lined with curved sound abatement devices 4130A in the form of non-woven textiles. The nonwoven textile 4131 forming sound abatement device 4130A is in some examples is configured to comprise at least two opposing outer surfaces 4136 and 4137, the two opposing outer surfaces spaced apart and connected by at least one side wall 4138. In the example of Fig. 4E, the nonwoven textile 4161 is configured to be curved in shape around an axis X parallel to outer surface 4136, such that surface 4136 is concave and opposing surface 4137 is convex. Sound abatement devices 4130A may include anynumber or shape of curves as required to enable a close fit or connection with the internal walls of chassis 4161.

[0158] In other examples, the sound abatement devices 4130A may be flexible and able to adapt to any curved surface against which they are mounted.

[0159] Sound abatement devices 4130A may be formed to include connection regions 4133 that may take the form of flanges, notches, grooves, protrusions or slits that allow the sound abatement device 4130A to be held in position within a housing, when connection regions 4133 cooperate with a corresponding feature inside the internal walls of the chassis 4016.

[0160] As seen if Fig. 4D and 4F and 4G, sound abatement devices 4013 A are releasably received within chassis 4016 and mounted flush against internal surface(s) 4040 to line the housing interior walls. Sound abatement devices 4130 may be mounted perpendicular to a gas flow in a housing, parallel to a gas flow in a housing or any angle therebetween, providing a material for sound to attenuate, pass through or reflect off, depending on mounting location. As sound abatement devices of the present technology may be consistently produced to specific dimensions and compositions, therefore ensuring consistent airflow, sound abatement devices 4103 may be positioned within the same chamber as flow restrictors 4111 or 4112, may be adjacent, proximate or directly abut flow restrictors.

[0161] Fig. 4F-1 shows arrows depicting and example of a gas flow path through pneumatic block. In an example, the housing and internal components cooperate to form an air flow path having at least one generally U-shape path from the housing inlet 4017 to the housing outlet 4019. For example, the U-shape air flow path may include an inlet leg extending from the housing inlet 4017, an outlet leg extending from the housing outlet 4019, and a connecting leg that interconnects the inlet leg and the outlet leg. In an example, the inlet leg and outlet leg are substantially parallel to one another. In an example, one or more flow restrictors and sound abatement devices are provided along the inlet-leg. In an example one or more sound abatement devices and flow restrictors are provided along the connecting leg. In an example one or more sound abatement devices and flow restrictors are provided along the outlet leg.

[0162] Depending on the shape of the pneumatic block, there may be one or multiple different sound abatement devices required to effectively line or cover internal surfaces 4040, with the sound abatement devices shaped to avoid or fit snuglyagainst internal components including but not limited to baffles, flanges, internal walls or connection means for example.

[0163] As seen in Fig. 4G, one sound abatement device 4130D is formed from a nonwoven textile 4161 as a substantially planar sheet with a thickness of 5-10mm, the nonwoven textile 4161 shaped around its perimeter to line an internal surface 4040 of chassis 4016. In the example of Fig 4G, this shaping includes a curved wall 4162, shaped to provide spacing for and surround blower 4142. Multiple layers of individual sound abatement devices 4130D may be placed on top of each other, either separately, or the may be connected or laminated together using mechanical means / thermal means. Fig.4G provides a further example of a smaller sound abatement device 4130E, shaped to surround and be retained by internal features of the chassis 4016. Any number of individual sound abatement devices may be included within a housing of a gas flow generation apparatus to absorb sound, the devices ranging and size and shape as required to enable lining of the internal surfaces 4040.

[0164] Fig. 4F shows sound abatement devices 4130B and 4130C in further examples of a sound abatement device that comprises a nonwoven textile 4131 held in a fixed dimension by a frame portion 4700. In examples, frame 4131 or 4700 may be overmolded with nonwoven textile 4131 or formed as an accessible cage type structure that allows for removal or replacement of an internally housed nonwoven textile.

[0165] In other examples not shown, sound abatement device 4130 may be molded directly onto the internal wall of the housing. The molding may be configured such that the internal housing wall forms at least a portion of a frame 4131 that provides support to sound abatement device 4130. Any examples of frame portions described herein may be formed or partially formed with the internal housing walls in some examples.

[0166] Frame portion 4700 supports a nonwoven textile 4161 at a fixed dimension ensuring any sound abatement device 4130B / 4130C held within the chassis 4016 or within any gas flow path of the gas generation device, does not move with use, providing a consistent quality of sound absorption and consistent sizing that can be readily replicated during mass manufacturing.

[0167] In some examples seen in Fig. 4F, frame portion 4700 is configured as a scaffold structure surrounding a substantially planar portion of nonwoven textile 4161, the scaffold having a front panel 4701 (and optionally an opposing back panel(not shown)) configured to cover at least one planar surface of the nonwoven textile and defining at least one aperture 4800, exposing nonwoven textile 4161 to the internal housing space defined by hollow chassis 4161, and subsequently providing the nonwoven textile 4161 for sound absorption. Frame portion 4700 may also comprise a frame edging 4702 connected to and supporting the perimeter or part thereof of non woven textile 4161.

[0168] In some examples, the frame portion comprises an edging 4203 surrounding a front and / or rear panel 4702, front and / or rear panel 4702 configured to define multiple apertures 4800 which in one example may have a hexagonal perimeter, forming a honeycomb style scaffold structure. Frame portion 4700 may be configured to define apertures 4800 of a range of sizes and shapes, such as circular, triangular, octagonal, oval, rectangular, square or irregular polygons, with larger apertures exposing more of the nonwoven textile size or shape. In one example of sound abatement device 4130C, a honeycomb scaffold structure is formed in a front panel 4702 and opposing rear panel (not shown) of frame portion 4700, the honeycomb structure incorporating multiple hexagonal or partially hexagonal walls defining apertures 4135 and a circular wall defining a larger aperture 4136. Frame portion 4700 may be configured such that front panel 4702 and / or an opposing rear panel is 40 - 95% porous, with the amount of porosity dictated by mounting location and exposure to a gas flow path.

[0169] In the example provided, aperture 4136 is dimension to expose a greater surface area of non-woven textile 4161 exposed to a passing gas flow, while still providing strength and dimension control to the sound abatement device.. Frame portion 4700 enables a region of nonwoven textile 4161 to be firmly supported across the gas path of gas moving through chassis 4016, ensuring rigidity and dimension control under pressure from a moving gas flow.

[0170] Frame portion 4700 may be configured to cover an edge portion or surface region of a nonwoven textile, with examples further seen in Figs 4H, 41 and 4J. Fig. 41 shows a cross-sectional view of nonwoven textile 4161 having frame portion 4700 formed as an overmolded edge, providing rigidity to the nonwoven textile by surrounding or partially surrounding the perimeter of the nonwoven textile 4161. Frame portion 4700 when formed as an edging 4720 may have a substantially U- shaped cross section, with the base of the “U” 4719 abutting an edge region of nonwoven textile 4161 and opposing side walls 4715 of the “U” shape 4716 moldedaround the side edges of front 4163 and rear 4164 surfaces of the nonwoven textile 4161. In some forms, side walls 4715 may configured or sized between 2mm - 10mm, framing the front and rear surfaces of the nonwoven textile 4161, with the size of side wall 4215 optionally differing on each surface, optionally changing at different regions around the perimeter of the nonwoven textile and sized to enable and facilitate incorporation on the non woven textile into the chassis 4016.

[0171] In some forms a retention feature 4717 may be incorporated into the frame portion in the form of a channel, protrusion, rim, flange or one half of a connection member, the retention feature designed to enable a fixed connection of the sound abatement device to the inside of the hollow cavity, reducing any rattling or movement that may increase sound int eh device rather than reduce it. Retention features 4717 may be formed on any surface of frame portion 4700 and in one example is a thin protrusion extending from base 4717 of edging 4720 and extending around or partially around the length of edging 4720. Retention feature 4717 enables sound abatement device 4130 to be slidably retained in a corresponding groove formed in an internal surface 4040 of chassis 4016.

[0172] Fig. 4J shows a top view of sound abatement device 4130D with an overmolded edging 4720 surrounding the perimeter of the nonwoven textile 4161.

[0173] Nonwoven textile 4161 is shaped with a perimeter that corresponds to a region of the internal chassis surface and a specific thickness that enables a snug fit within the chassis 4016 without disrupting air flow. The perimeter of nonwoven textile 4161 may be shaped to include connection portions that receive or connect to / abut ribs, flanges or protrusions formed on the internal surfaces of chassis 4016.

[0174] In some examples, sound abatement device 4130 is formed in substantially rectangular sheets of textile, curved around a transverse axis, perpendicular to the longitudinal axis of the rectangular nonwoven textile, and may include grooves 4131 or recesses 4132 that aid in connection. These connection portions may be formed using thermoforming or precision cutting for example. The curvature of the nonwoven textile may be fixed prior to assembly using techniques such as thermoforming, or a substantially flat piece of nonwoven textile may be used that conforms to the curved surface once inserted. The nonwoven textile may be any shape as required to effectively line at least a portion of the internal surface of a blower housing.

[0175] When sound abatement device 4130 is utilised in a gas flow generation device, reducing fibre migration from the nonwoven textile 4161 is beneficial to prevent small microfibres being released into the gas stream as air passes through or by the nonwoven textile, which may be detrimental to patient health if such fibres are inhaled into a patient’s lungs or airways.

[0176] Many nonwoven textiles in their raw state have a fluffy or fuzzy outer surface, with some fibres not fully adhered to the nonwoven textile web extending from the outer surface of the product. By treating the surface of the nonwoven textile, fibres can be more effectively retained within the nonwoven textile and not released when the sound abatement device is subject to friction, either by a passing air current or during installation and removal of the sound abatement device.

[0177] Fig 4K shows a close-up view of a nonwoven textile 4161 with a fluffy surface with fibres 4162 extending from the surface, prior to further surface treatment, with Fig. 4L demonstrating the smoother surface achieved following surface treatment.

[0178] A number of surface treatments may be applied to the nonwoven textile to form smooth surfaces that reduce or are resistant to fibre migration. Incorporation of the nonwoven textile with a frame portion as described in further detail above may also assist in the reduction of fibre migration.

[0179] Nonwoven textiles used in the present invention may be formed from a recyclable, synthetic material such as polypropylene, polyethylene terephthalate (PET), nylon, polyester or viscose for example. For medical applications in particular, the use of a synthetic nonwoven is preferred to meet the required regulatory requirements around hygiene, safety and quality of materials. In alternative examples, a combination of both natural and synthetic fibres may be used, or a combination of fibres having different lengths, strength, structure (hollow or solid, different cross- sectional shape such as round, trilobal, grooved, crimped) or origin may be used to create a nonwoven having optimised sound absorption capabilities.

[0180] The nonwoven textile used in the present invention may be needle- punched staple nonwoven textile, meltblown nonwoven textile, spunbond nonwoven textile manufactured using a thermal bonding process, spunlace nonwoven textile manufactured using hydroentanglement or flashspun nonwoven textile.

[0181] Surface finishing techniques on the nonwoven textiles may include mechanical / thermal-mechanical finishes such as splitting and winding, calendaring,glazing and heavy glazing, compressive finishing, singeing, nano-finishing, drying, shearing, flocking, perforating, polishing, softening and heat setting or chemical finishing including the use of coating agents.

[0182] Different manufacturing methods are suited to different fibre type and length and result in nonwovens with different acoustic absorption properties.

[0183] Increased ability to absorb sound is a preferred characteristic of the nonwoven used in the present invention, however different characteristics such as the ability of the nonwoven to hold a shape, respond to precision cutting, different surface textures may all be considered when selecting the optimum nonwoven for a particular application.

[0184] Referring to the figures, when sound abatement device 4130 is utilised in a gas flow generation device, reducing fibre migration from the nonwoven textile 4161 is beneficial to prevent small microfibres being released into the gas stream as air passes through or by the nonwoven textile, which may be detrimental to patient health if such fibres are inhaled into a patient’s lungs or airways.

[0185] Many nonwoven textiles in their raw state have a fluffy or fuzzy outer surface, with some fibres not fully adhered to the nonwoven textile web extending from the outer surface of the product. By treating the surface of the nonwoven textile, fibres can be more effectively retained within the nonwoven textile and not released when the sound abatement device is subject to friction, either by a passing air current or during installation and removal of the sound abatement device.

[0186] In one example, the non woven textile 4161 is polypropylene nonwoven and the surfaces of the nonwoven are glazed at 120 - 170°C to improve bonding of the nonwoven fibres. Surface glazing of nonwovens creates a smooth, polished surface on fabrics and can also impart stiffness to the product and is achieved by passing the nonwoven through smooth, heated rollers. Fig. 4M shows a sound abatement device 4130 with a glazed surface, with a microscopic view demonstrating the smooth areas 4400 imparted to the nonwoven fibres following glazing. In addition to smoothing the outer surface of the nonwoven fibres, applying the glazing process at a temperature that corresponds to the melting point of the nonwoven fibre encourages the fibres on the surface of the nonwoven to melt together, such that when cooled, a cohesive web is formed.

[0187] In some examples, the nonwoven textile is formed from polypropylene, polyester or combinations thereof. Surface glazing at temperatures that correspond tothe melting point of these compounds produce effective surface structures that reduce fibre migration in the sound abatement devices.

[0188]

[0189] Fig 4K shows a close up view of a nonwoven textile with a fluffy surface, prior to further surface treatment, with Fig. 4L demonstrating the smoother surface achieved following surface treatment.

[0190] In a further example, surface treatment to reduce fibre migration of the nonwoven may also be achieved by the addition of a scrim layer to one or more of the nonwoven surfaces. A scrim layer is an additional layer fused to the nonwoven to add stability, strength and / or improve surface smoothness and reduce fibre migration.

[0191] The scrim layer may be in the form of a synthetic such as polyester, polypropylene or polyethylene and is applied or laminated onto the surface of the nonwoven using thermal mechanical bonding, with or without an adhesive or resin binder added. The sound abatement devices of the present technology may use a spun-bond nonwoven scrim layer, and example of which is seen in Fig. 4N as an unbonded scrim layer 4500 shaped to conform to the surface of nonwoven textile 4161. A scrim layer may be laminated to the one or both surfaces of the non woven textile.

[0192] Incorporation of the nonwoven textile with a frame portion as described in further detail above may also assist in the reduction of fibre migration.

[0193] In some aspect of the present technology, the nonwoven textile is a formed as a member shaped to be received against an inner surface of a housing in a gas-flow generation apparatus. The shape may be a flat sheet having a regular or irregular edge shape to accommodate flanges, ridges channels or internal walls within the housing.

[0194] In some examples, the nonwoven is inelastic to encourage retention of a desired shape of the nonwoven textile.

[0195] The non wo ven textile may be formed from a single layer 1, 2, 3, 4, 5, 6, 7,8, 9, 10, 11, 12, 13, 14, 15, 16,17, 18, 19 or 20 - 25mm thick and in some examples2mm - 8mm thick. Alternatively, multiple layers of the nonwoven may be mounted to the housing on top or partially on top of each other, or may be mechanically or chemically bonded / laminated together to create a multi-layer member.

[0196] The nonwoven textile may be shaped to create a regular or irregular three dimensional polygonal or curved shape. One such method to create the shaped nonwovens is using thermoforming or pressure forming, ultrasonic cutting and welding, radio frequency cutting and welding, hot or cold die cutting or laser cutting. The use of such techniques provide for nonwovens having for example curved shapes to closely match the shape of a housing component, shaped surfaces that increase surface area of the nonwoven to improve sound absorption capabilities, or recesses, hooks or flanges to facilitate connection between two or more nonwoven textile members or between the nonwoven and a surface of the apparatus.

[0197] The surface roughness, texture or contour may differ across different regions of the nonwoven textile, for example one face of the textile may be relatively smooth to abut or line a housing wall and an opposing second face may have a rougher or textured surface to improve sound absorption.

[0198] In some examples of the present invention, a range of different nonwoven textile samples are used in the gas flow generation apparatus. Different properties of the three sample textiles are detailed in the table below:Table 1

[0199] The above properties are examples of a small range of nonwovens suitable for use in the present technology.

[0200] Characteristics of nonwovens that may be suitable for use in the present technology include one or more of;

[0201] - tensile strength of 20 kN / m - lOOkN / m;

[0202] - mass per unit area of 200 - 1200g / m2;

[0203] - sound absorption coefficient of 0.4 - 0.95 for sound in the 1 - 6kHz range;

[0204] - porosity of the nonwoven textile is between 50% - 90%;

[0205] - density of the nonwoven textile being 50-200kg / m3;

[0206] - fibre denier (D) being within the range of 1 - 20D.

[0207] The denier of the fibre used in the nonwoven textile may be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 1, 18, 19, 20 or fractions thereof denier fibre. In some examples a 6 denier fibre and a 15 denier fibre was used to create a nonwoven textile, with limited differences in acoustic performance identified between the different denier fibres based on initial objective and subjective testing.

[0208] The combination of the fibre denier together with the density of the nonwoven textile allows the manufacture of nonwoven with specific porosity characteristics. Following initial testing, high density materials offer better sound performance, however above approximately 170kg / m3 there were no notable improvements in sound attenuation. The desired density may be achieved by layering and bonding of nonwoven textiles during the manufacturing process.4.4.4 RPT device electrical components4.4.4.1 Power supply

[0209] A power supply 4210 may be located internal or external of the external housing 4010 of the RPT device 4000.

[0210] In one form of the present technology, power supply 4210 provides electrical power to the RPT device 4000 only. In another form of the present technology, power supply 4210 provides electrical power to both RPT device 4000 and humidifier 5000.4.4.4.2 Input devices

[0211] In one form of the present technology, an RPT device 4000 includes one or more input devices 4220 in the form of buttons, switches or dials to allow a person to interact with the device. The buttons, switches or dials may be physical devices, or software devices accessible via a touch screen. The buttons, switches or dials may, in one form, be physically connected to the external housing 4010, or may, in another form, be in wireless communication with a receiver that is in electrical connection to the central controller 4230.

[0212] In one form, the input device 4220 may be constructed and arranged to allow a person to select a value and / or a menu option.4.4.4.3 Central controller

[0213] In one form of the present technology, the central controller 4230 is one or a plurality of processors suitable to control an RPT device 4000. The central controller 4230 is show in Figs. 4C and 4C-1.

[0214] Suitable processors may include an x86 INTEL processor, a processor based on ARM® Cortex®-M processor from ARM Holdings such as an STM32 series microcontroller from ST MICROELECTRONIC. In certain alternative forms of the present technology, a 32-bit RISC CPU, such as an STR9 series microcontroller from ST MICROELECTRONICS or a 16-bit RISC CPU such as a processor from the MSP430 family of microcontrollers, manufactured by TEXAS INSTRUMENTS may also be suitable.

[0215] In one form of the present technology, the central controller 4230 is a dedicated electronic circuit.

[0216] In one form, the central controller 4230 is an application- specific integrated circuit. In another form, the central controller 4230 comprises discrete electronic components.

[0217] The central controller 4230 may be configured to receive input signal(s) from one or more transducers 4270, one or more input devices 4220, and / or the humidifier 5000.

[0218] The central controller 4230 may be configured to provide output signal(s) to one or more of an output device 4290, a pressure generator 4140, a therapy device controller 4240, a data communication interface 4280, and / or the humidifier 5000.

[0219] In some forms of the present technology, the central controller 4230 is configured to implement the one or more methodologies described herein, such as the one or more algorithms 4300 which may be implemented with processor-control instructions, expressed as computer programs stored in a non-transitory computer readable storage medium, such as memory 4260. In some forms of the present technology, the central controller 4230 may be integrated with an RPT device 4000. However, in some forms of the present technology, some methodologies may be performed by a remotely located device. For example, the remotely located device may determine control settings for a ventilator or detect respiratory related events by analysis of stored data such as from any of the sensors described herein.4.4.4.4 Protection circuits

[0220] The one or more protection circuits 4250 in accordance with the present technology may comprise an electrical protection circuit, a temperature and / or pressure safety circuit.4.4.4.5 Memory

[0221] In accordance with one form of the present technology the RPT device 4000 includes memory 4260, e.g., non-volatile memory. In some forms, memory 4260 may include battery powered static RAM. In some forms, memory 4260 may include volatile RAM.

[0222] Memory 4260 may be located on the PCBA 4202. Memory 4260 may be in the form of EEPROM, or NAND flash.

[0223] Additionally, or alternatively, RPT device 4000 includes a removable form of memory 4260, for example a memory card made in accordance with the Secure Digital (SD) standard.

[0224] In one form of the present technology, the memory 4260 acts as a non- transitory computer readable storage medium on which is stored computer program instructions expressing the one or more methodologies described herein, such as the one or more algorithms 4300.4.4.4.6 Data communication systems

[0225] In one form of the present technology, a data communication interface 4280 is provided, and is connected to the central controller 4230 (see e.g., Fig. 4C). Data communication interface 4280 may be connectable to a remote external communication network 4282 and / or a local external communication network 4284. The remote external communication network 4282 may be connectable to a remote external device 4286. The local external communication network 4284 may be connectable to a local external device 4288.

[0226] In one form, data communication interface 4280 is part of the central controller 4230. In another form, data communication interface 4280 is separate from the central controller 4230, and may comprise an integrated circuit or a processor.

[0227] In one form, remote external communication network 4282 is the Internet. The data communication interface 4280 may use wired communication (e.g. via Ethernet, or optical fibre) or a wireless protocol (e.g. CDMA, GSM, LTE) to connect to the Internet.

[0228] In one form, local external communication network 4284 utilises one or more communication standards, such as Bluetooth, or a consumer infrared protocol.

[0229] In one form, remote external device 4286 is one or more computers, for example a cluster of networked computers. In one form, remote external device 4286 may be virtual computers, rather than physical computers. In either case, such aremote external device 4286 may be accessible to an appropriately authorised person such as a clinician.

[0230] The local external device 4288 may be a personal computer, mobile phone, tablet or remote control.4.4.4.7 Output devices including optional display, alarms

[0231] An output device 4290 in accordance with the present technology may take the form of one or more of a visual, audio and haptic unit. A visual display may be a Liquid Crystal Display (LCD) or Light Emitting Diode (LED) display.4.4.4.7.1 Display driver

[0232] A display driver 4292 receives as an input the characters, symbols, or images intended for display on the display 4294, and converts them to commands that cause the display 4294 to display those characters, symbols, or images.4.4.4.7.2 Display

[0233] A display 4294 is configured to visually display characters, symbols, or images in response to commands received from the display driver 4292. For example, the display 4294 may be an eight-segment display, in which case the display driver 4292 converts each character or symbol, such as the figure “0”, to eight logical signals indicating whether the eight respective segments are to be activated to display a particular character or symbol.4.5 AIR CIRCUIT

[0234] An air circuit 4170 in accordance with an aspect of the present technology is a conduit or a tube constructed and arranged to allow, in use, a flow of air to travel between two components such as RPT device 4000 and the patient interface 3000 or 3800.

[0235] In particular, the air circuit 4170 may be in fluid connection with the outlet of the pneumatic block 4020 and the patient interface. The air circuit may be referred to as an air delivery tube. In some cases there may be separate limbs of the circuit for inhalation and exhalation. In other cases a single limb is used.

[0236] In some forms, the air circuit 4170 may comprise one or more heating elements configured to heat air in the air circuit, for example to maintain or raise the temperature of the air. The heating element may be in a form of a heated wire circuit, and may comprise one or more transducers, such as temperature sensors. In one form, the heated wire circuit may be helically wound around the axis of the air circuit 4170. The heating element may be in communication with a controller such as a centralcontroller 4230. One example of an air circuit 4170 comprising a heated wire circuit is described in United States Patent 8,733,349, which is incorporated herewithin in its entirety by reference.4.5.1 HUMIDIFIER4.5.2 Humidifier overview

[0237] In one form of the present technology there is provided a humidifier 5000 (e.g. as shown in Fig. 5A) to change the absolute humidity of air or gas for delivery to a patient relative to ambient air. Typically, the humidifier 5000 is used to increase the absolute humidity and increase the temperature of the flow of air (relative to ambient air) before delivery to the patient’s airways.

[0238] The humidifier 5000 may comprise a humidifier reservoir 5110, a humidifier inlet 5002 to receive a flow of air, and a humidifier outlet 5004 to deliver a humidified flow of air. In some forms, as shown in Fig. 5 A and Fig. 5B, an inlet and an outlet of the humidifier reservoir 5110 may be the humidifier inlet 5002 and the humidifier outlet 5004 respectively. The humidifier 5000 may further comprise a humidifier base 5006, which may be adapted to receive the humidifier reservoir 5110 and comprise a heating element 5240.4.5.2.1 BREATHING WAVEFORMS

[0239] Fig. 6A shows a model typical breath waveform of a person while sleeping. The horizontal axis is time, and the vertical axis is respiratory flow rate. While the parameter values may vary, a typical breath may have the following approximate values: tidal volume Vt 0.5L, inhalation time Ti 1.6s, peak inspiratory flow rate Qpeak 0.4 L / s, exhalation time Te 2.4s, peak expiratory flow rate Qpeak -0.5 L / s. The total duration of the breath, Ttot, is about 4s. The person typically breathes at a rate of about 15 breaths per minute (BPM), with Ventilation Vent about 7.5 L / min. A typical duty cycle, the ratio of Ti to Ttot, is about 40%.4.6 GLOSSARY

[0240] For the purposes of the present technology disclosure, in certain forms of the present technology, one or more of the following definitions may apply. In other forms of the present technology, alternative definitions may apply.4.6.1.1 General

[0241] Air: In certain forms of the present technology, air may be taken to mean atmospheric air, and in other forms of the present technology air may be taken to mean some other combination of breathable gases, e.g. oxygen enriched air.

[0242] Ambient: In certain forms of the present technology, the term ambient will be taken to mean (i) external of the treatment system or patient, and (ii) immediately surrounding the treatment system or patient.

[0243] For example, ambient humidity with respect to a humidifier may be the humidity of air immediately surrounding the humidifier, e.g. the humidity in the room where a patient is sleeping. Such ambient humidity may be different to the humidity outside the room where a patient is sleeping.

[0244] In another example, ambient pressure may be the pressure immediately surrounding or external to the body.

[0245] In certain forms, ambient (e.g., acoustic) noise may be considered to be the background noise level in the room where a patient is located, other than for example, noise generated by an RPT device or emanating from a mask or patient interface. Ambient noise may be generated by sources outside the room.

[0246] Automatic Positive Airway Pressure (APAP) therapy: CPAP therapy in which the treatment pressure is automatically adjustable, e.g. from breath to breath, between minimum and maximum limits, depending on the presence or absence of indications of SDB events.

[0247] Continuous Positive Airway Pressure (CPAP) therapy: Respiratory pressure therapy in which the treatment pressure is approximately constant through a respiratory cycle of a patient. In some forms, the pressure at the entrance to the airways will be slightly higher during exhalation, and slightly lower during inhalation. In some forms, the pressure will vary between different respiratory cycles of the patient, for example, being increased in response to detection of indications of partial upper airway obstruction, and decreased in the absence of indications of partial upper airway obstruction.

[0248] Flow rate: The volume (or mass) of air delivered per unit time. Flow rate may refer to an instantaneous quantity. In some cases, a reference to flow rate will be a reference to a scalar quantity, namely a quantity having magnitude only. In other cases, a reference to flow rate will be a reference to a vector quantity, namely aquantity having both magnitude and direction. Flow rate may be given the symbol Q. ‘Flow rate’ is sometimes shortened to simply ‘flow’ or ‘airflow’.

[0249] In the example of patient respiration, a flow rate may be nominally positive for the inspiratory portion of a breathing cycle of a patient, and hence negative for the expiratory portion of the breathing cycle of a patient. Device flow rate, Qd, is the flow rate of air leaving the RPT device. Total flow rate, Qt, is the flow rate of air and any supplementary gas reaching the patient interface via the air circuit. Vent flow rate, Qv, is the flow rate of air leaving a vent to allow washout of exhaled gases. Leak flow rate, QI, is the flow rate of leak from a patient interface system or elsewhere. Respiratory flow rate, Qr, is the flow rate of air that is received into the patient's respiratory system.

[0250] Flow therapy. Respiratory therapy comprising the delivery of a flow of air to an entrance to the airways at a controlled flow rate referred to as the treatment flow rate that is typically positive throughout the patient’s breathing cycle.

[0251] Humidifier. The word humidifier will be taken to mean a humidifying apparatus constructed and arranged, or configured with a physical structure to be capable of providing a therapeutically beneficial amount of water (H2O) vapour to a flow of air to ameliorate a medical respiratory condition of a patient.

[0252] Leak'. The word leak will be taken to be an unintended flow of air. In one example, leak may occur as the result of an incomplete seal between a mask and a patient's face. In another example leak may occur in a swivel elbow to the ambient.

[0253] Noise, conducted (acoustic)'. Conducted noise in the present document refers to noise which is carried to the patient by the pneumatic path, such as the air circuit and the patient interface as well as the air therein. In one form, conducted noise may be quantified by measuring sound pressure levels at the end of an air circuit.

[0254] Noise, radiated (acoustic): Radiated noise in the present document refers to noise which is carried to the patient by the ambient air. In one form, radiated noise may be quantified by measuring sound power / pressure levels of the object in question according to ISO 3744.

[0255] Noise, vent (acoustic): Vent noise in the present document refers to noise which is generated by the flow of air through any vents such as vent holes of the patient interface.

[0256] Oxygen enriched air: Air with a concentration of oxygen greater than that of atmospheric air (21%), for example at least about 50% oxygen, at least about 60%oxygen, at least about 70% oxygen, at least about 80% oxygen, at least about 90% oxygen, at least about 95% oxygen, at least about 98% oxygen, or at least about 99% oxygen. “Oxygen enriched air” is sometimes shortened to “oxygen”.

[0257] Medical Oxygen-. Medical oxygen is defined as oxygen enriched air with an oxygen concentration of 80% or greater. Patient-. A person, whether or not they are suffering from a respiratory condition.

[0258] Pressure: Force per unit area. Pressure may be expressed in a range of units, including cmHiO, g-f / cm2and hectopascal. 1 cmbhO is equal to 1 g-f / cm2and is approximately 0.98 hectopascal (1 hectopascal = 100 Pa = 100 N / m2= 1 millibar ~ 0.001 atm). In this specification, unless otherwise stated, pressure is given in units of cmHiO.

[0259] The pressure in the patient interface is given the symbol Pm, while the treatment pressure, which represents a target value to be achieved by the interface pressure Pm at the current instant of time, is given the symbol Pt.

[0260] Respiratory Pressure Therapy. The application of a supply of air to an entrance to the airways at a treatment pressure that is typically positive with respect to atmosphere.

[0261] Ventilator: A mechanical device that provides pressure support to a patient to perform some or all of the work of breathing.4.6.1.2 Materials & their properties

[0262] Hardness: Refers to durometer or indentation hardness, which is a material property measured by indentation of an indentor (e.g., as measured in accordance with ASTM D2240).• ‘Soft’ materials may include silicone or thermo-plastic elastomer (TPE), and may, e.g. readily deform under finger pressure.• ‘Hard’ materials may include polycarbonate, polypropylene, and may not e.g. readily deform under finger pressure.

[0263] Silicone or Silicone Elastomer: A synthetic rubber. In this specification, a reference to silicone is a reference to liquid silicone rubber (LSR) or a compression moulded silicone rubber (CMSR). One form of commercially available LSR is SILASTIC (included in the range of products sold under this trademark), manufactured by Dow Corning. Another manufacturer of LSR is Wacker. Unless otherwise specified to the contrary, an exemplary form of LSR has a Shore A (orType A) indentation hardness in the range of about 35 to about 45 as measured using ASTM D2240.

[0264] Polycarbonate-, a thermoplastic polymer of Bisphenol-A Carbonate.4.6.1.3 Mechanics

[0265] Axes: a. Neutral axis: An axis in the cross-section of a beam or plate along which there are no longitudinal stresses or strains. b. Longitudinal axis: An axis extending along the length of a shape. The axis generally passes through a center of the shape. c. Circumferential axis: An axis oriented perpendicularly with respect to the longitudinal axis. The axis may be specifically present in pipes, tubes, cylinders, or similar shapes with a circular and / or elliptical cross section.

[0266] Deformation: The process where the original geometry of a member changes when subjected to forces, e.g. a force in a direction with respect to an axis. The process may include stretching or compressing, bending and, twisting.

[0267] Elasticity: The ability of a material to return to its original geometry after deformation.

[0268] Floppy structure or component: A structure or component that will change shape, e.g. bend, when caused to support its own weight, within a relatively short period of time such as 1 second.

[0269] Resilience: Ability of a material to absorb energy when deformed elastically and to release the energy upon unloading.

[0270] Resilient: Will release substantially all of the energy when unloaded. Includes e.g. certain silicones, and thermoplastic elastomers.

[0271] Rigid structure or component: A structure or component that will not substantially change shape when subject to the loads typically encountered in use. An example of such a use may be setting up and maintaining a patient interface in sealing relationship with an entrance to a patient's airways, e.g. at a load of approximately 20 to 30 cmH20 pressure.

[0272] As an example, an I-beam may comprise a different bending stiffness (resistance to a bending load) in a first direction in comparison to a second, orthogonal direction. In another example, a structure or component may be floppy in a first direction and rigid in a second direction.

[0273] Stiffness (or rigidity) of a structure or component: The ability of the structure or component to resist deformation in response to an applied load. The load may be a force or a moment, e.g. compression, tension, bending or torsion. The structure or component may offer different resistances in different directions. The inverse of stiffness is flexibility.

[0274] Viscous: The ability of a material to resist flow.

[0275] Visco-elasticity: The ability of a material to display both elastic and viscous behaviour in deformation.

[0276] Yield: The situation when a material can no longer return back to its original geometry after deformation.4.6.1.4 Respiratory cycle

[0277] Apnea: According to some definitions, an apnea is said to have occurred when flow falls below a predetermined threshold for a duration, e.g. 10 seconds. An obstructive apnea will be said to have occurred when, despite patient effort, some obstruction of the airway does not allow air to flow. A central apnea will be said to have occurred when an apnea is detected that is due to a reduction in breathing effort, or the absence of breathing effort, despite the airway being patent. A mixed apnea occurs when a reduction or absence of breathing effort coincides with an obstructed airway.

[0278] Breathing rate: The rate of spontaneous respiration of a patient, usually measured in breaths per minute.

[0279] Duty cycle: The ratio of inhalation time, Ti to total breath time, Ttot.

[0280] Effort (breathing): The work done by a spontaneously breathing person attempting to breathe.

[0281] Expiratory portion of a breathing cycle: The period from the start of expiratory flow to the start of inspiratory flow.

[0282] Flow limitation: Flow limitation will be taken to be the state of affairs in a patient's respiration where an increase in effort by the patient does not give rise to a corresponding increase in flow. Where flow limitation occurs during an inspiratory portion of the breathing cycle it may be described as inspiratory flow limitation. Where flow limitation occurs during an expiratory portion of the breathing cycle it may be described as expiratory flow limitation.

[0283] Types of flow limited inspiratory waveforms:(i) Flattened: Having a rise followed by a relatively flat portion, followed by a fall.(ii) M-shaped: Having two local peaks, one at the leading edge, and one at the trailing edge, and a relatively flat portion between the two peaks.(iii) Chair-shaped: Having a single local peak, the peak being at the leading edge, followed by a relatively flat portion.(iv) Reverse-chair shaped: Having a relatively flat portion followed by single local peak, the peak being at the trailing edge.

[0284] Hypopnea: According to some definitions, a hypopnea is taken to be a reduction in flow, but not a cessation of flow. In one form, a hypopnea may be said to have occurred when there is a reduction in flow below a threshold rate for a duration. A central hypopnea will be said to have occurred when a hypopnea is detected that is due to a reduction in breathing effort. In one form in adults, either of the following may be regarded as being hypopneas:(i) a 30% reduction in patient breathing for at least 10 seconds plus an associated 4% desaturation; or(ii) a reduction in patient breathing (but less than 50%) for at least 10 seconds, with an associated desaturation of at least 3% or an arousal.

[0285] Hyperpnea: An increase in flow to a level higher than normal.

[0286] Inspiratory portion of a breathing cycle: The period from the start of inspiratory flow to the start of expiratory flow will be taken to be the inspiratory portion of a breathing cycle.

[0287] Patency (airway): The degree of the airway being open, or the extent to which the airway is open. A patent airway is open. Airway patency may be quantified, for example with a value of one (1) being patent, and a value of zero (0), being closed (obstructed).

[0288] Positive End-Expiratory Pressure (PEEP): The pressure above atmosphere in the lungs that exists at the end of expiration.

[0289] Peak flow rate (Qpeak): The maximum value of flow rate during the inspiratory portion of the respiratory flow waveform.

[0290] Respiratory flow rate, patient airflow rate, respiratory airflow rate (Qr): These terms may be understood to refer to the RPT device’s estimate of respiratory flow rate, as opposed to “true respiratory flow rate” or “true respiratory flow rate”,which is the actual respiratory flow rate experienced by the patient, usually expressed in litres per minute.

[0291] Tidal volume (Vt): The volume of air inhaled or exhaled during normal breathing, when extra effort is not applied. In principle the inspiratory volume Vi (the volume of air inhaled) is equal to the expiratory volume Ve (the volume of air exhaled), and therefore a single tidal volume Vt may be defined as equal to either quantity. In practice the tidal volume Vt is estimated as some combination, e.g. the mean, of the inspiratory volume Vi and the expiratory volume Ve.

[0292] Inhalation Time (Ti): The duration of the inspiratory portion of the respiratory flow rate waveform.

[0293] Exhalation Time (Te): The duration of the expiratory portion of the respiratory flow rate waveform.

[0294] Total Time (Ttot): The total duration between the start of one inspiratory portion of a respiratory flow rate waveform and the start of the following inspiratory portion of the respiratory flow rate waveform.

[0295] Typical recent ventilation: The value of ventilation around which recent values of ventilation Vent over some predetermined timescale tend to cluster, that is, a measure of the central tendency of the recent values of ventilation.

[0296] Upper airway obstruction (UAO): includes both partial and total upper airway obstruction. This may be associated with a state of flow limitation, in which the flow rate increases only slightly or may even decrease as the pressure difference across the upper airway increases (Starling resistor behaviour).

[0297] Ventilation (Vent): A measure of a rate of gas being exchanged by the patient’s respiratory system. Measures of ventilation may include one or both of inspiratory and expiratory flow, per unit time. When expressed as a volume per minute, this quantity is often referred to as “minute ventilation”. Minute ventilation is sometimes given simply as a volume, understood to be the volume per minute.4.6.1.5 Ventilation

[0298] Adaptive Servo- Ventilator (ASV): A servo-ventilator that has a changeable, rather than fixed target ventilation. The changeable target ventilation may be learned from some characteristic of the patient, for example, a respiratory characteristic of the patient.

[0299] Backup rate: A parameter of a ventilator that establishes the minimum breathing rate (typically in number of breaths per minute) that the ventilator will deliver to the patient, if not triggered by spontaneous respiratory effort.

[0300] Cycled: The termination of a ventilator's inspiratory phase. When a ventilator delivers a breath to a spontaneously breathing patient, at the end of the inspiratory portion of the breathing cycle, the ventilator is said to be cycled to stop delivering the breath.

[0301] Expiratory positive airway pressure (EPAP): a base pressure, to which a pressure varying within the breath is added to produce the desired interface pressure which the ventilator will attempt to achieve at a given time.

[0302] End expiratory pressure (EEP): Desired interface pressure which the ventilator will attempt to achieve at the end of the expiratory portion of the breath. If the pressure waveform template □(□) is zero-valued at the end of expiration, i.e.> (□) = 0 when > = 1, the EEP is equal to the EPAP.

[0303] Inspiratory positive airway pressure (IPAP): Maximum desired interface pressure which the ventilator will attempt to achieve during the inspiratory portion of the breath.

[0304] Pressure support: A number that is indicative of the increase in pressure during ventilator inspiration over that during ventilator expiration, and generally means the difference in pressure between the maximum value during inspiration and the base pressure (e.g., PS = IPAP - EPAP). In some contexts, pressure support means the difference which the ventilator aims to achieve, rather than what it actually achieves.

[0305] Servo-ventilator: A ventilator that measures patient ventilation, has a target ventilation, and which adjusts the level of pressure support to bring the patient ventilation towards the target ventilation.

[0306] Spontaneous / Timed (S / T): A mode of a ventilator or other device that attempts to detect the initiation of a breath of a spontaneously breathing patient. If however, the device is unable to detect a breath within a predetermined period of time, the device will automatically initiate delivery of the breath.

[0307] Swing: Equivalent term to pressure support.

[0308] Triggered: When a ventilator, or other respiratory therapy device such as an RPT device or portable oxygen concentrator, delivers a volume of breathable gas to a spontaneously breathing patient, it is said to be triggered to do so. Triggeringusually takes place at or near the initiation of the respiratory portion of the breathing cycle by the patient's efforts.4.6.1.6 Shape of structures

[0309] Products in accordance with the present technology may comprise one or more three-dimensional mechanical structures, for example a mask cushion or an impeller. The three-dimensional structures may be bounded by two-dimensional surfaces. These surfaces may be distinguished using a label to describe an associated surface orientation, location, function, or some other characteristic. For example a structure may comprise one or more of an anterior surface, a posterior surface, an interior surface and an exterior surface. In another example, a seal-forming structure may comprise a face-contacting (e.g. outer) surface, and a separate non-facecontacting (e.g. underside or inner) surface. In another example, a structure may comprise a first surface and a second surface.4.6.1.7 Curvature of two dimensional surfaces

[0310] A description of the shape at a given point on a two-dimensional surface in accordance with the present technology may include multiple normal crosssections. The multiple cross-sections may cut the surface in a plane that includes the outward normal (a “normal plane”), and each cross-section may be taken in a different direction. Each cross-section results in a plane curve with a corresponding curvature. The different curvatures at that point may have the same sign, or a different sign. Each of the curvatures at that point has a magnitude, e.g. relatively small.

[0311] Principal curvatures and directions: The directions of the normal planes where the curvature of the curve takes its maximum and minimum values are called the principal directions.

[0312] Region of a surface: A connected set of points on a surface. The set of points in a region may have similar characteristics, e.g. curvatures or signs.

[0313] Saddle region: A region where at each point, the principal curvatures have opposite signs, that is, one is positive, and the other is negative (depending on the direction to which the imaginary person turns, they may walk uphill or downhill).

[0314] Dome region: A region where at each point the principal curvatures have the same sign, e.g. both positive (a “concave dome”) or both negative (a “convex dome”).

[0315] Cylindrical region: A region where one principal curvature is zero (or, for example, zero within manufacturing tolerances) and the other principal curvature is non-zero.

[0316] Planar region: A region of a surface where both of the principal curvatures are zero (or, for example, zero within manufacturing tolerances).

[0317] Edge of a surface: A boundary or limit of a surface or region.

[0318] Path: In certain forms of the present technology, ‘path’ will be taken to mean a path in the mathematical - topological sense, e.g. a continuous space curve from f(0) to f(l) on a surface. In certain forms of the present technology, a ‘path’ may be described as a route or course, including e.g. a set of points on a surface. (The path for the imaginary person is where they walk on the surface, and is analogous to a garden path).

[0319] Path length: In certain forms of the present technology, ‘path length’ will be taken to mean the distance along the surface from f(0) to f( 1 ), that is, the distance along the path on the surface. There may be more than one path between two points on a surface and such paths may have different path lengths. (The path length for the imaginary person would be the distance they have to walk on the surface along the path).

[0320] Straight-line distance: The straight-line distance is the distance between two points on a surface, but without regard to the surface. On planar regions, there would be a path on the surface having the same path length as the straight-line distance between two points on the surface. On non-planar surfaces, there may be no paths having the same path length as the straight-line distance between two points. (For the imaginary person, the straight-line distance would correspond to the distance ‘as the crow flies’.)

[0321] Tangent unit vector (or unit tangent vector): For each point on a curve, a vector at the point specifies a direction from that point, as well as a magnitude. A tangent unit vector is a unit vector pointing in the same direction as the curve at that point. If an imaginary person were flying along the curve and fell off her vehicle at a particular point, the direction of the tangent vector is the direction she would be travelling.

[0322] Unit normal vector: As the imaginary person moves along the curve, this tangent vector itself changes. The unit vector pointing in the same direction that thetangent vector is changing is called the unit principal normal vector. It is perpendicular to the tangent vector.

[0323] Binormal unit vector: The binormal unit vector is perpendicular to both the tangent vector and the principal normal vector.

[0324] Osculating plane: The plane containing the unit tangent vector and the unit principal normal vector.

[0325] Torsion of a space curve: The torsion at a point of a space curve is the magnitude of the rate of change of the binormal unit vector at that point. It measures how much the curve deviates from the osculating plane. A space curve which lies in a plane has zero torsion. A space curve which deviates a relatively small amount from the osculating plane will have a relatively small magnitude of torsion (e.g. a gently sloping helical path). A space curve which deviates a relatively large amount from the osculating plane will have a relatively large magnitude of torsion (e.g. a steeply sloping helical path).4.7 OTHER REMARKS

[0326] A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in Patent Office patent files or records, but otherwise reserves all copyright rights whatsoever.

[0327] Unless the context clearly dictates otherwise and where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit, between the upper and lower limit of that range, and any other stated or intervening value in that stated range is encompassed within the technology. The upper and lower limits of these intervening ranges, which may be independently included in the intervening ranges, are also encompassed within the technology, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the technology.

[0328] Furthermore, where a value or values are stated herein as being implemented as part of the technology, it is understood that such values may be approximated, unless otherwise stated, and such values may be utilized to any suitable significant digit to the extent that a practical technical implementation may permit or require it.

[0329] Furthermore, “approximately”, “substantially”, “about”, or any similar term used herein means + / - 5-10% of the recited value.

[0330] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this technology belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present technology, a limited number of the exemplary methods and materials are described herein.

[0331] When a particular material is identified as being used to construct a component, obvious alternative materials with similar properties may be used as a substitute. Furthermore, unless specified to the contrary, any and all components herein described are understood to be capable of being manufactured and, as such, may be manufactured together or separately.

[0332] It must be noted that as used herein and in the appended claims, the singular forms "a", "an", and "the" include their plural equivalents, unless the context clearly dictates otherwise.

[0333] All publications mentioned herein are incorporated herein by reference in their entirety to disclose and describe the methods and / or materials which are the subject of those publications. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present technology is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates, which may need to be independently confirmed.

[0334] The terms "comprises" and "comprising" should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.

[0335] The subject headings used in the detailed description are included only for the ease of reference of the reader and should not be used to limit the subject matter found throughout the disclosure or the claims. The subject headings should not be used in construing the scope of the claims or the claim limitations.

[0336] Although the technology herein has been described with reference to particular examples, it is to be understood that these examples are merely illustrativeof the principles and applications of the technology. In some instances, the terminology and symbols may imply specific details that are not required to practice the technology. For example, although the terms "first" and "second" may be used, unless otherwise specified, they are not intended to indicate any order but may be utilised to distinguish between distinct elements. Furthermore, although process steps in the methodologies may be described or illustrated in an order, such an ordering is not required. Those skilled in the art will recognize that such ordering may be modified and / or aspects thereof may be conducted concurrently or even synchronously.

[0337] It is therefore to be understood that numerous modifications may be made to the illustrative examples and that other arrangements may be devised without departing from the spirit and scope of the technology.

Claims

5 CLAIMS1. A flow generation apparatus for generating a flow of breathable gas at a positive pressure for respiratory therapy comprising: a housing having an inlet and an outlet; a blower comprising a motor and an impeller to draw ambient gases into the housing through the inlet and out of the housing through the outlet; and at least one sound abatement device comprising a nonwoven textile, the sound abatement device lining or partially lining one or more internal surfaces of or within the housing.

2. The flow generation apparatus of claim 1, wherein the sound abatement device is formed entirely of synthetic materials.

3. The flow generation apparatus of any one of claims 1 or 2, wherein the nonwoven textile of the sound abatement device is configured to comprise at least two opposing outer surfaces, the two opposing outer surfaces spaced apart and connected by at least one side wall.

4. The flow generation apparatus of claim 3, wherein the nonwoven textile is configured to be curved in shape around an axis parallel to one outer surface of the nonwoven textile.

5. The flow generation apparatus of claim 3, wherein the nonwoven textile is configured to be curved in shape around an axis perpendicular to a surface of the nonwoven textile.

6. The flow generation apparatus of any one of claims 1 to 5, wherein the housing comprises multiple chambers, at least one of the chambers comprising at least one sound abatement and at least one flow restrictor.

7. The flow generation apparatus of any one of claims 1 to 6, wherein the apparatus is configured to define a gas flow path between the inlet and outlet of the housing, and the sound abatement device is positioned at least partially within the gas flow path.

8. The flow generation apparatus of any one of claims 1 to 7, wherein an internal surface of the housing comprises one or more flanges, recesses, apertures, channels, notches or hooks configured to receive the at least one sound abatement device.

9. The flow generation apparatus of any one of claims 1 to 8, wherein the sound abatement device comprises at least one integrally formed flange, recess, aperture, channel, notch, hook or adhesive configured to enable connection of the sound abatement device to an internal surface of the housing of the apparatus.

10. The flow generation apparatus of any one of claims 1 to 9, wherein the sound abatement device is encapsulated or partially encapsulated by a frame portion.

11. The flow generation apparatus of claim 10, wherein the frame portion is an overmolded edging.

12. The flow generation apparatus of claim 11, wherein the frame portion comprises a porous scaffold.

13. The flow generation apparatus of claim 12, where in the frame portion comprises a front panel of porous scaffold and an opposing back panel of porous scaffold, the front and back panels of porous scaffold connected and spaced apart by at least one side wall, the nonwoven textile located between the front panel and back panel of the porous scaffold, a perimeter of the nonwoven textile surrounded by the at least one side wall of the frame portion.

14. The flow generation apparatus of claim 13, wherein the porous scaffold is configured to define apertures in the scaffold having a cross-sectional area of 4mm2- 10000mm2, when the cross-section is measured substantially parallel to the nonwoven textile.

15. The flow generation apparatus of any one of claims 10-14, wherein the frame portion comprises at least one retention feature configured to releasably retain the sound abatement device within the housing.

16. The flow generation apparatus of any one of claims Ito 15, wherein the sound abatement device is formed from a single material.

17. The flow generation apparatus of any one of claims 1 to 16, wherein the nonwoven textile is a needle-punched nonwoven textile, melt-blown nonwoven textile, spunbond nonwoven textile, spunlace nonwoven textile and / or flashspun nonwoven textile.

18. The flow generation apparatus of any one of claims 1 to 17, wherein the nonwoven textile is formed using thermal bonding, hydroentanglement, ultrasonic pattern bonding, needle-punching and / or chemical bonding.

19. The flow generation apparatus of any one of claims 1 to 18, wherein the nonwoven textile of the sound abatement device comprises at least one thermally treated surface to reduce fibre migration from the nonwoven textile.

20. The flow generation apparatus of claim 19, wherein the nonwoven textile includes two opposing thermally treated surfaces.

21. The flow generation apparatus of claim 19 or claim 20, wherein a thermally treated surface is formed by glazing the a surface of the nonwoven textile at 120 - 170°C.

22. The flow generation apparatus of any one of claims 1 to 21, wherein the nonwoven textile comprises two opposing outer surfaces, the two opposing outer surfaces having a different surface texture, surface roughness or contour from each other.

23. The flow generation apparatus of any one of claims 1 to 22, wherein the nonwoven textile has a fibre denier (D) of 3 - 15.

24. The flow generation apparatus of any one of claims 1 to 23, wherein the nonwoven textile has a density of 50 - 200kg / m3.

25. The flow generation apparatus of any one of claims 1 to 24, wherein the porosity of the nonwoven textile is between 50% - 90%.

26. The flow generation apparatus of any one of claims 1 to 25, wherein the nonwoven textile is formed from one or more sheets or pieces of nonwoven textile between 1 - 20mm thick.

27. A sound abatement device comprising a nonwoven textile suitable for attenuating and / or deflecting sound waves inside a housing of an apparatus for supplying a flow of breathable gas at a positive pressure for respiratory therapy.

28. The sound abatement device of claim 27, wherein the nonwoven textile of the sound abatement device is configured to comprise at least two opposing outer surfaces, the two opposing outer surfaces spaced apart and connected by at least one side wall.

29. The sound abatement device of claim 28, wherein the nonwoven textile is configured to be curved in shape around an axis parallel to one outer surface of the nonwoven textile.

30. The sound abatement device of claim 28, wherein the nonwoven textile is configured to be curved in shape around an axis perpendicular to a surface of the nonwoven textile.

31. The sound abatement device of any one of claims 27 to 30, wherein the sound abatement device comprises or is shaped to define at least one integrally formed flange, recess, aperture, channel, notch, hook or adhesive.

32. The sound abatement device of any one of claims 27 to 31, wherein the sound abatement device is encapsulated or partially encapsulated by a frame portion.

33. The sound abatement device of claim 32, wherein the frame portion comprises an overmolded edging.

34. The sound abatement device of claim 32 or 33, wherein the frame portion comprises a porous scaffold.

35. The sound abatement device of claim 34, where in the frame portion comprises a front panel of porous scaffold and an opposing back panel of porous scaffold, the front and back panels of porous scaffold connected and spaced apart by at least one side wall, the nonwoven textile located between the front panel and back panel of the porous scaffold, a perimeter of the nonwoven textile surrounded by the at least one side wall of the frame portion.

36. The sound abatement device of claim 34 or 35, wherein the porous scaffold is configured to define apertures in the scaffold having a cross-sectional area of 2mm2- 20mm2,when the cross-section is measured substantially parallel to the nonwoven- textile.

37. The sound abatement device of any one of claims 32 to 36, wherein the frame portion comprises at least one retention feature connectable to a connection member on a separate device or apparatus.

38. The sound abatement device of any one of claim 27 to 37, wherein the sound abatement device is formed from a single material.

39. The sound abatement device of any one of claims 27 to 38, wherein the nonwoven textile is a needle-punched nonwoven textile, melt-blown nonwoven textile, spunbond nonwoven textile, spun-lace nonwoven textile and / or flashspun nonwoven textile.

40. The sound abatement device of any one of claims 27 to 39, wherein the nonwoven textile is formed using thermal bonding, hydroentanglement, ultrasonic pattern bonding, needle-punching and / or chemical bonding.

41. The sound abatement device of any one of claims 27 to 40, wherein the nonwoven textile of the sound abatement device comprises at least one glazed surface.

42. The sound abatement device of claim 41, wherein the nonwoven textile includes two opposing glazed surfaces to reduce fibre migration from the nonwoven textile.

43. The sound abatement device of claim 41, wherein the at least one glazed surface is formed by glazing the a surface of the nonwoven textile at 120 - 170°C.

44. The sound abatement device of any one of claims 27 to 43, wherein the sound abatement device comprises two opposing surfaces, the two opposing surfaces having a different surface texture, surface roughness or contour from each other.

45. The sound abatement device of any one of claims 27 to 44, wherein the nonwoven textile has a fibre denier (D) of 3 - 15.

46. The sound abatement device of any one of claims 27 to 45, wherein the nonwoven textile has a density of 50 - 200kg / m3.

47. The sound abatement device of any one of claims 27 to 46, wherein the porosity of the nonwoven textile is between 50% - 90%.

48. The sound abatement device of any one of claims 27 to 47, wherein the nonwoven textile is formed from one or more sheets or pieces of nonwoven textile between 1 - 20mm thick.

49. The sound abatement device of claim 48, wherein the nonwoven textile includes multiple layers of differently sized nonwoven textile laminated together to form an irregularly shaped sound abatement device.

50. The sound abatement device of any one of claims 27 to 49, wherein the device comprises one or more areas of shaped, moulded or textured outer surface to increase a surface area of the sound abatement device.

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