WO2015048849A1 - Mask vent with side wall - Google Patents

Abstract

A vent arrangement for a mask system includes a mask component and a mask vent provided to the mask component. The mask vent includes a plurality of vent holes each extending through a thickness of the mask component and each including a vent exit, and a continuous side wall structured to surround the plurality of vent exits of the vent holes.

Description

MASK VENT WITH SIDE WALL

1 CROSS-REFERENCE TO RELATED APPLICATIONS

[1] Not Applicable

2 STATEMENT REGARDING FEDERALLY SPONSORED

RESEARCH OR DEVELOPMENT

[2] Not Applicable

3 THE NAMES OF PARTIES TO A JOINT RESEARCH

DEVELOPMENT

[3] Not Applicable

4 SEQUENCE LISTING

[4] Not Applicable

5 BACKGROUND OF THE INVENTION

5.1 FIELD OF THE INVENTION

[5] The present technology relates to one or more of the diagnosis, treatment, prevention, and amelioration of respiratory disorders. In particular, the present technology relates to medical devices, and their use for treating respiratory disorders and for preventing respiratory disorders.

5.2 DESCRIPTION OF THE RELATED ART

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

[7] 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 me ah' into the venous blood and carbon dioxide to move out. 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 t 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 West, Respiratory Physiology- the Essentials.

[8] A range of respiratory disorders exist,

[9] Obstructive S leep Apnea (OS A), a form of S leep Disordered Breathing

(SDB), is. characterised by occlusion or obstruction of the upper air passag during sleep. It results from a combination of an abnormally small upper airway and the normal loss of muscle tone in the region of the tongue, soft palate and posterior oropharyngeal wall during sleep. The condition causes the affected patient to stop breathing for periods typically of 30 to 120 seconds 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. See US Patent 4,944310 (Sullivan).

[10] Cheyne-Stokes Respiration (CSR) is a disorder of a patient's respiratory controller in which there are rhythmic alternating periods of waxing and waning ventilation during sleep, causing 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. See US Patent 6,532,959 (Berthon-Joiies).

1.1 1 ] Obesity Hyperventilation Syndrome (OHS) is defined as the combination of severe obesity and awake chronic hvpercapnia, in the absence of other known causes for hypoventilation. Symptoms include dyspnea, morning headache and excessive daytime sleepiness,

[12] Chronic Obstructive Pulmonary Disease (CQPD) 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.

[ 13] Neuromuscular Disease (HMD) is a broad term that encompasses many diseases and ailments that impair the functioning of the muscles either directly vi intrinsic muscle pathology, or indirectly via nerve pathology. Some NMD patients are characterised by progressive muscular impairment leading to loss of

ambulation, being wheelchair-bound, swallowing difficulties, respiratory muscle weakness and, eventually, . death from respiratory failure. Neuromuscular disorders can be divided into rapidly progressive and slowly progressive: (i) Rapidly progressive disorders: Characterised by muscle impairment that worsens over months and results in death within a few years (e.g. Amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers); (ii) Variable or slowly progressive disorders; Characterised by muscle impairment that worsens over years and only mildly reduces life expectancy (e.g. Limb girdle,

Facioscapulohumeral and Myotonic muscular dystrophy). Symptoms of

respiratory failure in NMD include: increasing generalised weakness, dysphagia, dyspnea on exertion and at rest fatigue, sleepiness, morning headache, and difficulties with .concentration and mood changes.

[14] 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 respirator 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.

[15] Otherwise healthy individuals ma take advantage of systems and devices to prevent respiratory disorders from arising. 5,2, ί Systems

[16] One known product used for treating sleep disordered breathing is the S9

Sleep Therapy System, manufactured by ResMed.

5.2.2 Therapy

[17] Nasal Continuous Positive Airway Pressure (CPAP) therapy has been used to treat Obstructive Sleep Apnea (OSA). The hypothesis is that continuous positive airwa pressure acts as a pneumatic splint and may prevent upper airway occlusion by pushing the soft palate and tongue forward and away from the posterior oropharyngeal wall .

[18] Non-invasive ventilation (NIV) has been used to treat QHS, COFD, MD and Chest Wall disorders.

5.2.3 Patient Interface

[19] The application of a supply of air at positi ve pressure to the entrance of the airways of a patient is facilitated by the use of a patient interf ce, such as a nasal mask, full-face mask or nasal pillows. A range of patient interface devices are known, however a number of them suffer from being one or more of obtrusi ve, aesthetically undesirable, poorly fitting, difficult to use, and uncomfortable especially when worn for long periods of time or when a patient is unfamiliar with a system. Masks designed solely for aviators a part of personal protection equipment or for the administration of anaesthetic may be tolerable for their original application, but nevertheless be undesirably uncomfortable to be worn for extended periods, for example, while sleeping.

5.2.3.1 Seal-forming portion

[20] Patient interfaces typically include a seal-forming portion.

[21] One type of seal-forming portion extends .around the periphery of the

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

[22] Another type of seal-forming portion incorporates a Hap seal of thin

material so positioned about the peripher of the mask so as to provide a self- sealing action against the face of the user when positive pressure i applied within the mask. Like the previous style of seal forming portion, if the match between the face and the mask is not good, additional force may be required to effect a seal, or the mask may leak. Furthermore, if the shape of the seal-forming portion does not match that of the patient, it may crease or buckle in use, giving rise to leaks.

[23] Another form of seal-forming portion may use adhesive to effect a seal.

Some patients may find it inconvenient to constantly apply and remove an adhesive to their face.

124] A range of patient interface seal-forming portion technologies are

disclosed in the following patent applications, assigned to ResMed Limited: WO 1998/004,3 0; WO 2006/074,513; WO 2010/1 5,785.

5.2.3.2 Positioning and stabilising

[25] A seal-forming portion of a patient interface used for positive air pressure therapy is subjec to the corresponding force of the ai pressure to disrupt a seal. Thus a variety of techniques have been used to position the seal-forming portion, and to maintain it in sealing relation with the appropriate portion of the face,

[26] One technique is the use of adhesives. See for example US Patent

publication US 201 /0000534.

[27] Another technique is the use of one or more straps and stabilising

harnesses. Many such harnesses suffer from being one or more of ill-fitting, bulky, uncomfortable and awkward to use. 5.2_*3.3 Vent technologies

[28] Some forms of patient interface systems may include a vent to allow the washout of exhaled carbon dioxide. Many such vents are noisy. Others may block in use and provide insufficient wasshout. Some vents may be disruptive of the sleep of a bed-partner 1 100 of the patient 1000, e.g. through noise or foeussed airflow.

[29] ResMed Limited has developed a number of improved mask vent

technologies. See WO 1998/034,665; WO 2000/078,381 ; US 6,58.1 ,594; US Patent Application; US 2009/0050156; US Patent Application 2009/0044808.

[30] Table of noise of prior masks (ISO 17510-2:2007, 10 cmHiO pressure at 1 metre):

Mask name Mask type A- weighted A-weighted Year (approx.) J

sound power sound pressure

level dbA dbA

{uncertainly) (uncertainty)

Glue-on (*) nasal 50.9 42. 198.1

ResCare nasal 31.5 23.5 1993

standard (*)

ResMed nasal 29.5 21.5 1998

Mirage (*)

ResMed nasal 36 (3) 28 (3 ) 2000

UltraMirage

ResMed nasal 32 (3) 24 (3) 2002

Mirage Aetiva

ResMed nasal 30 (3) 22 (3) 2008

Mirage Micro

ResMed nasal 2 (3) 22 (3) 2008

Mirage S ftGei

ResMed nasal 26 (3) 1.8 (3) 20.1.0

Mirage FX

ResMed nasal pillows 37 29 2004

Mirage Swift

(*)

ResMed nasal pillows 28 (3) 20 (3) 200

Mirage S wift II ResMed nasal pi llows 25 (3) 17 (3) 2008

Mirage S ift

LT

(* one specimen only, measured using test method specified in IS03744 CPAP mode at 10cmB₃O)

Sound pressure values of a variety of objects are listed belo w:

5.2.3.4 Nasal pillow technologies

[33] One form of nasal pillow is found in the Adam Circuit manufactured by

Purita Bennett. Another nasal pillow, or nasal puf f is the subject of US Patent 4,782,832 (Trimble et al.), assigned to Puritan-Bennett Corporation.

[34] ResMed Limited has manufactured the following^' products that

incorporate nasal pillows: SWIFT nasal pillows mask, SWIFT II nasal pillows mask. SWIFT LT nasal pillow's mask, SWIFT FX nasal pillows mask and LIBERTY full-face mask, The following patent applications, as igned to ResMed Limited, describe nasal pillows masks: International Patent Application

WO2004/073,778 (describing amongst other things aspects of ResMed SWIFT nasal pillows), US Patent Application 2009/0044808 (describing amongst other things aspects of ResMed SWIFT LT nasal pillows); International Patent

Applications WO 2005/063,328 and WO 2006/1 0,903 (describing amongst other things aspects of ResMed LIBERTY full-face mask); International Patent Application WO 2009/052,560 (describing amongst other things aspects of ResMed SWIFT FX nasal pillows).

5.2.4 PAP Device

[35] The air at positive pressure is typically supplied to the airway of a patient by a PAP device- such as a motor-driven blower. The outlet of the blower is connected via a flexible delivery conduit to a patient interface as described above.

5.2.5 Mandibular repositioning

[36] A mandibular repositioning device (MRD) is one of the treatment options for sleep apnea. It is a custom made, adjustable oral appliance available from a dentist that holds the lower jaw in a forward position during sleep. This mechanical protrusio expands the space behind the tongue, puts tension on the pharyngeal walls to reduce coilapse of the airway and diminishes palate vibration.

6 BRIEF SUMMARY OF THE TECHNOLOGY

[37] The present technology is directed towards providing medical devices used in the diagnosis, .amelioration,, treatment,, or prevention of respiratory disorders having one or more of improved comfort, cost, efficacy, ease of use and man u cturabi lit .

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

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

[40] Another aspect of the present technology relates to a gas washout vent for a mask system structured to disperse r diffuse the exhaust vent flow, e.g., to reduce air jetting and noise.

[41 ] Another aspect of the present technology relates to a gas washout vent including a side wall or hood at least partly surrounding one or more vent holes to disperse or diffuse the exhaust vent flow. [42] Another aspect of the present technology relates to a vent arrangement for a mask system including a mask component and a mask vent provided to the mask component. The mask vent includes a plurality of vent holes each extending through a thickness of the mask component and each including a vent exit, and continuous side wall structured to surround the plurality of vent exits of the vent holes.

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

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

7 BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE

DRAWINGS

[45] The present technology is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in whic like reference numerals refer to similar element including:

7.1 TREATMENT SYSTEMS

[46] Fig. la shows a system in accordance with the present technology. A

patient 1000 wearing a patient interface 3000, receives a suppl of air at positive pressure from a PAP device 4000. Air from the PAP device is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000.

[47] Fig, lb shows a PAP device 4000 in use on a patient 1000 with a nasal mask 3000.

[48] Fig. l.c shows a PAP device 4000 in use on a patient ί 000 with a full-face mask 3000. 1.0

7.2 THERAPY

7.2.1 Respiratory system

[49] 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.

[50] Fig. 2b shows a view of a human upper airwa including the nasal cavity, nasal bone, lateral nasal cartilage, greater alar cartilage, nostril, lip superior, lip inferior, larynx., hard palate, soft palate, oropharynx, tongue, epiglottis, vocal folds, oesophagus and trachea.

7.2.2 Facial anatomy

[51] Fig, 2c is a front view of a face with several features of surface anatomy identified including the lip superior, upper vermillion, lower vemullion, li inferior, mouth width, endocanthion, a nasal ala, nasolabial sulcus and cheilion,

[52] Fig. 2d is a side view of a head with several features of surface anatomy identified including glabella, sellion, pronasaie, suhnasaie, lip superior, lip inferior, suprarnenton, nasal ridge, otobasion superior and otobasion inferior. Also indicated are the directions superior & inferior, and anteri r & posterior.

[53] Fig. 2e is a further side view of a head. The approximate locations of the

Frankfort horizontal and nasolabial angle are indicated.

[54] Fig, 2f shows a base view of a nose.

[55 ] Fig. 2g shows a side view of the superficial features of a nose .

[56] Fig. 2h shows subcutaneai structures of the nose, including lateral

cartilage, septum cartilage, greater alar cartilage, lesser alar cartilage and fibrofatty tissue.

[57] Fig. 2i shows a medial dissection of a nose, approximately se veral

millimeters from a sagittal plane, amongst other things showing the septum cartilage and medial cms of greater alar cartilage. [58] Fig, 2j shows a front view of the hones of a skull including the frontal, temporal, nasal and zygomatic bones. Nasal concha are indicated, as are the maxilla, mandible and mental protuberance,

[59] Fig. 2k sho s a lateral view of a skull with the outline of the surface of a head, as well as several muscles. The following bones are shown: frontal, sphenoid, nasal, zygomatic, maxilla, mandible, parietal, temporal and occipital. The mental protuberance is indicated. The following muscles are shown;

digastricus, masseter sternocleidomastoid and trapezius.

[60] Fig. 21 shows an anterolateral view of a nose.

7.3 PATIENT INTERFACE

[61] Fig. 3-1 shows mask system including a mask vent according to an

example of the present technology,

[62] Fig. 3-2 shows a mask vent according to an example of the present

technology.

[63] Fig. 3-3 shows a mask vent according to an example of the present

technology.

[64] Fig. 3-4 shows a mask vent according to an example of the present

technology.

[65] Figs. 3-5-1 to 3-5-7 show various views of an elbow assembly including a mask, vent according to an example of the present technology.

[66] Figs. 3-6-1 to 3-6-2 show various views of an elbo w assembly including a mask vent according to an example of the present technology.

[67] Figs. 3-6-3 to 3-6-9 show various views of the mask vent of Figs. 3-6-1 to 3-6-2 removed from the elbow assembly.

[68] Figs. 3-7-1 to 3-7-5 show a mask system including the elbow assembly of

Figs. 3-6-1 to 3-6-2 according to an example of the present technology. [69] Figs. 3-8-1 to 3-8-2 show various views of an elbow assembly including a mask vent according to an example of the present technology.

[70] Figs. 3-9-1 to 3-9-2 show various views of an elbow assembly including mask vent according to an example of the present technology,

[71] Figs, 3-10-1 to 3-10-2 show various views of an elbow assembly

including a mask vent according t an example of the present technology.

[72] Figs, 3-11-1 to 3-1 1-2 show various views of an elbow assembly

including a mask vent according to an example of the present technology.

[73] Figs. 3-12-1 to 3-1.2-2 show various views of an elbow assembly

including a mask vent according to an example of the present technology.

[74] Figs. 3-13- 1 to 3-13-2 show various views of an elbow assembly

including a mask vent according to an example of the present technology.

7.4 PAP DEVICE

[75] Fig. 4a shows a PAP device in accordance with one form of the present technology,

8 DETAILED DESCRIPTION OF EXAMPLES OF THE

TECHNOLOGY

[76] Before the present technology is described in furthe 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.

8.1 TREATMENT S YSTEMS

[77] In one form, the present technology comprises apparatus for treating a respiratory disorder. The apparatus may comprise a PAP device 4000 for supplying pressurised respiratory gas, such as air, t the patien 1.000 vi an air deli very tube leading to a patient interface 3000. 1.3

8.2 THERAPY

[78] In one form, the present technology comprise a method for treating

respiratory disorder comprising the step of applying positive pressure to the entrance of the airways of a patient 1000.

8.2.1 Nasal CPAP for OSA

[7 J In one form, the present technology comprises a method of treating

Obstructive Sleep Apnea in a patient by applying nasal continuous positive airway pressure to the patient.

[80] In certain embodiments of the present technology, a supply of air at

positive pressure, is provided to the nasal passages of the patient vi one or both nares.

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

8.3 PATIENT INTERFACE 3000

[82] A non-invasive patient interface 3000 in accordance with one aspect of the present technolog comprise the following functional aspects: a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilising structure (e.g., headgear), and a connection port 3600 for connection to air circuit, e.g., see Fig. 3-7-5 for example. In some forms a functional aspect may be provided by one or more physical components. In some forms, one physical component ma provide one or more functional aspects. In use the seal-forming structure 3.100 is arranged to surround an entrance to the airways of the patient so as to facilitate the supply of air at positi ve pressure to the airways.

8.3.1 Seal-forming structure 3100

[83] In one form of the present technology, a seal -forming structure 3100

provides a sealing- orming surface, and may additionally provide a cushioning function.

[84] A seal-forming structure 3100 in accordance with the present technology may be constructed from a soft, flexible, resilient material such as silicone. 1.4

[85] In one form, the seaWbrming structure 3100 comprises a sealing flange

3110 and a support flange 3120, e.g., see Fig. 3-7-5 for example. In an example, the sealing flange 31 10 comprises a relatively thin member with a thickness of less than about 1mm, for example about. 0.25mm. to about, 0.45mm, that extends around the perimeter of the plenum chamber 3200. Support flange 3120 may be relatively thicker than the sealing flange 31 1.0. The support flange 3120 is disposed bet wee the sealing flange 31 10 and the marginal edge of the plenum chamber 3200, and extends at least part of the way around the perimeter. The support flange 120 is or includes a spring-like element and functions to support the sealin flange 3110 from buckling in use. In use the sealing flange 1 10 can readily respond to system pressure in the plenum chamber 3200 acting on it underside to urge it into tight sealing engagement with the face,

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

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

[88] in one form the non-invasive patient interface 3000 comprises a seal- forming portion that forms a seal in use on an upper lip region (that is, the Up superior) of the patient's face.

[89] In one form the non-invasive patient interface 3000 comprises a seal- forming portion that forms a seal in use on a chin-region of the patient's face. 8.3.2 Plenum chamber 3200

[90 J The plenum chamber 3200 may have a perimeter that is shaped to be complementary to the surface contour of the face of an average person in the region where a seal will form, in use. In use, a marginal edge of the plenum chamber 3200 is positioned in close proximity to an adjacent surface of the face. Actual contact with the face i provided by the seal-forming structure 3100, The seal -forming structure 3100 may extend in use about the entire perimeter of the plenum chamber 3200.

8.3.3 Positioning and stabilising structure 3300

[ 1] The seal-forming structure 3100 of the patient interface 3000 of the

present technology may be held in sealing position in use by the positioning and stabilising structure.

8.3.4 Vent 3400

[92] In one form, the patient interface 3000 may include a vent 3400

constructed and arranged to allow for the washout of exhaled carbon di xide, e.g., see Fig. 3-7-5.

[93] One form of vent 3400 in accordance with the presen technology

comprise a plurality of holes, for example, about 2 to about 40 holes, about 5 to about 20 holes, about 20 to about 80.holes, about 40 to about 60 holes, or about 45 to about 55 holes. In an alternative implementation, the vent 3400 can comprise a woven mesh structure comprising numerous microscopic holes.

[94] The vent 3400 may be located in the plenum chamber. Alternatively, the vent may be located in a decoupling structure, e.g. swiyeL

[95] Fig. 3-1 shows a patient interface in accordance with one form of the present technology including a mask system or mask 1 0 including a rigid or semi-rigid portion 110 (often referred to as a shel l or frame) and a soft, patient contacting portion 120 adapted to form a seal with the patient's nose and/or mouth (often referred to as the seal forming structure, cushion, or nasal prong

arrangement). An elbow assembly may be provided to the frame and adapted to 1.6 be connected to an air delivery tube that delivers breathable gas to the patient. However, it should be appreciated that other mask arrangements are possible, e.g., not rigid (e.g., constructed of cloth),

[96] One or more gas washout vents or vent arrangements 140 are provided to the mask or associated conduit to discharge exhaled gas from the mask to atmosphere. In examples, the one or more vents may be provided to a mask component of the mask, i.e., to the frame and/or to the elbow assembly of the mask. One or more vents in the associated conduit are also possible.

[97] It should be appreciated that each vent may be adapted for use with any suitable interface type, e.g., nasal masks, full-face masks, nose and mouth masks, nasal prongs, pillows, nozzles, eannulae, etc.

[98] The vent arrangements in accordance with example of the present

technology are structured to disperse or diffuse the exhaust vent flow. Increased dispersion or diffusion of exhaust vent flo reduces disturbing or unfavourable effects of vent airflow, e.g., air jetti ng onto bed clothes/pillows and bed partners, noise.

[99] In examples, one or more side walls are provided around the washout vents or holes to surround or enclose the vent outlet or vent exit of the vent holes and reduce the unfavourable effects of vent airflow.

[ lOOj In an example, venting flow at 12 cm¾0 pressure is about 40 L/m, and air velocity at each vent opening is about 45 m/s about (162 km/h). Such high velocity vent airflow will cause vent airflow from all the -adjacent vent holes to converge with one another and pull in additional air surrounding the venting area into the converged stream due to the Venturi effect. The amount of air pulled into the converged stream can be more than 10 times larger than the original flow in some examples. To prevent or at least reduce additional air from being pulled into the vent airflow, a side wall is provided around the venting area according to examples of the present technology . [1013 In an example, the side wall reduces negative pressure along the surface adjacent the vent outlet which reduces air being pulled into the vent stream. This al lows greater dispersion or diffusion of the vent airflow adjacent the vent outlet and at least reduces convergence of the air stream to reduce air velocity downstream from the vent outlet. In an example, the air velocity downstream from the venting area .(e,g., about 300 mm downstream from the venting area) provided with a side wall may be at least 1/2 or less (e.g., 1/3) of the ai velocity downstream from the venting area with no side wall. As a result venting noise (e.g., sound power (dB)) is reduced, as is disruption to an bed-partner 1100 of the patient 1000. in effect, the venting flow has been spread over a wider area, achieving a more even or uniform flow profile across the walled area, thereby decreasing its velocity. The amount of reduction of downstream air velocity increases with the height of the side wall up to the limit whic is reached wit uniform flow.

[102] The greater the density of vent holes, the smaller the holes ma be made while maintaining the same venting flow rate. It may he shown that a greater density of smaller holes improves the amount of diffusion for the same height of surrounding side wall. In other words, as the density of vent holes increases, the side wall height may be reduced while preserving the same reduction in downstream air velocity at a given distance from the vent. In one example, 36 tapered vent holes of 0.75 mm diameter are disposed on a uniform hexagonal grid with inter-hole spacin of 2.5 mm. In thi example, the side wall height is 10 mm.

[1 3] In an example, as shown in Fig. 3-1, the mask vent 140 is provided to the mask frame 110 of the mask system 100. In the illustrated example, the mask, system includes the mask frame 1 10, the cushion 120 provided to the frame and adapted to form a seal with the patient's nose and mouth, and a shroud 1 0 provided t the frame and structured to attach headgear t the mask system. The lower portion of the frame includes an opening 1 1.2 adapted to receive or otherwise communicate with an elbow assembly, and the upper portion of the frarne includes the mask vent 140 fo gas washout. As illustrated, the bottom end of the shroud 130 includes an opening 132 to accommodate the elbow assembly and the top end of the shroud 130 includes an opening 134 to accommodate the 1.8 mask vent 140. Further examples and details of such mask system are disclosed in International. Publication No. WO 2009/108995, which is incorporated herein by reference in its entirety. However, it should be appreciated that the mask vent 140 may be adapted for use with other suitable interface types.

[1.04] As illustrated, the mask vent 140 includes a venting area 141 having a plurality of vent holes 142. Each vent hole extends through a thickness of the mask frame and each includes a vent exit. The mask vent 140 includes a continuous side wall 150 provided to the mask frame structured t surround the pluralit of vent exits of the vent holes 142, In an alternative example, the side wall may at least, partly surround one or more of the vent holes.

[105] The term "side wall" should be understood to include not only structures that project outwards from the mask component, such as the side wall 150, but also structures that project inwards from tile mask component, such as a wall surrounding a recess in the mask component. In an example of such a

configuration, as described below, the mask vent may be recessed within an interior of the mask, i.e., the side wall of the- vent supports the ventin area within an interior of the mask.

[1063 In an alternative example, the side wall may include a hood to at least partly surround, or enclose one or more of the vent holes.

[107] In the illustrated example, the side wail 150 extends in the direction of the vent airflow (e.g., perpendicular to the exterior surface 115 of the mask frame 10 and/or perpendicular to a longitudinal axis of eac vent hole 142). In alternative examples, the side wall may be angled with respect to the exterio surface of the mask frame and/or the longitudinal axis of each vent hole.

[ 108] In the illustrated example, the side wail 150 includes a uniform or

constant height along its perimeter, e.g., side wall includes substantially the same height from its connection to the frame to its free end. However, in an_. alternative example, the side wall may include one or more portions with different heights along its perimeter. 1.9

[109] In the illustrated example, the side wall 150 includes a uniform or

constant thicknes along its entire perimeter and from its connection to the frame to its free end. However, in an alternative example, the thickness of the side wall may be tapered along its height, e.g., tapered from its connection to the frame to its free end. Also, in an alternative example, the side wall may include different thicknesses along its perimeter.

[110] In the illustrated example, the vent holes 142 are arranged in columns, e.g., to allow mote holes to be fitted into a smaller space. As illustrated, the vent arrangement includes a center column including five holes which is flanked by inner intermediate columns each including five holes which is flanked by outer intermediate columns each including four holes which is flanked by outside columns each including four holes. The holes in the outside columns are aligned with holes in the inner intermediate columns, which are offset from, holes in the center column and outer intermediate column, forming a hexagonal grid arrangement. It should be appi-eciated that each column may include any suitable number of holes, and the columns may be arranged in other suitable manners with respect to one another.

[1 11] In the illustrated example, the vent holes 1.42 are arranged to provide a venting area 141 with a generally oblong, ovoid, or oval shape. As illustrated, the side wall 150 is continuous and is structured to surround the entire ventin area 141, e.g., side wall includes generally similar shape to the venting area, e.g., generally oblong, ovoid, or oval shaped side wall. However, in alternative examples, the side wall ma include a different shape than the venting area. Also, the side wall may be structured to only surround one or more portions of the venting area. In addition, it should be appreciated that the venting area and side wall may have other suitable shapes, e.g., depending on mask configuration, venting requirements, etc.

[112] For example, Figs. 3-2 to 3-4 illustrate alternative side wall arrangements.

In Fig. 3-2, the side wall 250 includes a hexagonal shape that surrounds the venting area 241 with vent holes 242. in Fig. 3-3, the side wall 350 include a circular shape that surrounds the venting area 341 with vent holes 342. In Fig. 3- 4, the side wall 450 includes a cireular shape that surrounds the venting area 441 with vent holes 442, and a plurality of truncated interior walls Or ribs 445 are provided within the side wall 450 and extend at least partially through the ventins area 441. As illustrated, the interior walls are arranged i a radial mariner from an axis of the circular side w ll However, it should be appreciated that the interior walls or ribs may have other suitable shapes, e,.g., arcuate or non-linear shape, and may be arranged within the ventin area in other suitable manners.

11 13] Each vent hole may have a generally part conic shape, including opposed walls that converge from a larger diameter to a. smaller diameter, as viewed in the direction of exhausted gas. Alternatively,, each vent hole may have a generally cylindrical shape with a substantially constant diameter along its length.

[ 114] In. an alternative example, the mask vent may be provided to the elbow assembly of the mask system. For example, the mask vent may be integrated or integrally formed in one piece with the elbow assembly. Alternatively, the mask vent may be retrofit to an existing elbow assembly, e.g., replace an original or existing mask vent on an elbow assembly.

[1.15] For example, Figs. 3-5-1 to 3-5-7 show the mask vent 540 integrall

formed (e.g.. molded) in one piece with the elbow assembl 580, The

arrangement provides a single piece elbow assembly with removable parts.

{ 1 16] As illustrated, the elbow assembly 580 includes a first end 581 structured to releasably engage with an opening in a mask frame and a second end 582 structured to releasably engage with an air delivery tube. In the illustrated example, the first end 581 includes a .flexible quick release mechanism including a T-shaped collar 583 structured to releasably engage a flange surrounding the opening in the mask frame with a snap-fit. Further examples and detail of such quick release mechanism are disclosed in U.S. Patent. No. 6,907,882, which is incorporated herein by reference in its entirety. However, it should be appreciated that the elbow assembly may be connected or otherwise communicated with the opening in the mask frame in other suitable manners. [117] A baffle 584 is provided within Che interior portion of the el ow assembly and separates the intake port 590 and the exhaust por 592, e.g., see Figs. 3-5-6 and 3-5-7, The mask vent 540 is provided at the outlet of the exhaust port 592. In this manner, exhalation gases from an interior of the mask can flow through exhaust port 592 of the elbow assembly 580, through the mask vent 540, and to the atmosphere.

[118] As illustrated, the mask vent 540 includes an inlet portion 544 to receive gas from the outlet of the exhaust port 592 of the elbow assembly, a vent portion 546 including the plurality of vent holes 542, and an outlet portion 548 to receive gas from the outlets of the vent holes 542. In the example, the inlet portion 544 includes a arcuate or otherwise angled side wall 545 to guide exhaust gas from the outlet towards the vent and outlet portions. In the illustrated example, as best shown in Fig. 3-5-7, the axes of the vent holes 542 and a longitudinal, axis al of the outlet portion 548 are oriented to direct exhaust gas in a .direction that is slightly offset or possibly parallel to a longitudinal axis a2 of the second end 582 of the elbow assembl (e.g., axes oriented about 0-45° from the axis of the second end), e.g., to ensure gas is vented in. a direction away from the mask system and the patient. In the example, the outlet portion 548 provides a continuous, side wail 550 around the vent portion and vent holes thereof to enhance dispersion or diffusion of exhaust vent flow as described above.

[ 119] I the illu trated example, the vent holes 542 are provided through an interior wall 549 of the mask vent 540 and arranged in columns of five vent holes, and the side wall 550 includes a generally rectangular shape thai surrounds the vent holes and extends in the direction of the vent airflow. However, as noted above, it should be appreciated that the vent holes and side wall may have other suitable arrangements.

[1203 Figs. 3-6-1 to 3-6-9 show an elbow assembly 680 and mask vent 640 according to another example of the present technology. In contrast to the example shown in Figs. 3-5-1 to 3-5-7, the mask vent 640 is provided as a vent cap that is formed separately from the elbow assembly 680 and attached thereto. In an example, the vent ca may be retrofit to an existing elbow assembly, e.g.. 2 vent cap replaces elastorneric vent cover on elbow assembly disclosed in U.S. Patent No. -6,907 $^'82 for example.

[121] As illustrated in Fig. 3-6-2. the elbow assembly 680 includes a flange 686 provided at a distal end of an annular wail 687 surrounding the outlet of the exhaust port 692. "The vent cap 640 is structured to releasably engage the .flange 686, e.g., with a snap-fit, to connect the vent cap 640 to the elbow assembly 680. Remaining aspects of the elbow assembly 680, e.g., first end 681 with flexible quick release mechanism, second end 682, baffle 684 separating intake port 690 and exhaust port 692 is similar to elbow assembly 580 described above.

[ 122] The vent cap 640 includes a main bod 643 providing an inlet portion 644 with arcuate or angled side wall 645 to guide exhaust gas from the outlet of the elbow assembly towards the vent, a vent portion 646 including interior wall 64 with the plurality of vent holes 642, and an outlet portion 648 including side wall 650 to diffuse vent flow as described above.

[ 123] A support wall 647 is provided to the inlet portion 644 along it inlet opening. As illustrated, the support wall 647 includes a non-continuous structure, e.g., first and second wall portions 647.1 and 647.2, e.g., see Figs. 3-6-3 and 3-6- 6. However, it. should be appreciated that the support wall may have other suitable structures, e.g.. continuous wall structure.

[ 124] An engagement or seal ring 660, e.g., constructed of a more flexible

material than the main body 643, is provided to the support wall 647. The engagement ring 660 includes grooves 661 through its thickness that are adapted to receive respective wall portions 647.1 and 647.2 of the support wall 647 (e.g., see Figs. 3-6-2, 3-6-3, 3-6-6, and 3-6-9) so as to attach the engagement ring to the support wall. The engagement ring 660 may be formed separately and attached to the support wall 647, or the engagement ring 660 may be integrally formed along with the main body 643 and support wall thereof, e.g., co-molded.

[125] As best shown in Fig, 3-6-9, the engagement, ring 660 includes an annular groove 662 along its inside surface. The .in-side surface may he ramped or tapered along it entry opening 664 to facilitate engagement and alignment of the engagement ring with the flange on the elbow assembly. Fig, 3-6-2 shows the vent cap 640 assembled to the elbow assembly 680, with the flange 686 on the elbow assembly 680 engaged within the groove 662 of the engagement ring 660 of the vent cap 640.

[1.26] Figs. 3-7-1 to 3-7-5 show the elbow assembly 680 and mask vent 640 of Figs, 3-6-1 to 3-6-9 provided to a mask system 600 according to an example of the present technology. The mask system 600 includes a. mask frame 610, cushion 620, and forehead support 625, further examples and detaiis of sueh mask system being disclosed in U.S. Patent No. 7,523,754, which is incorporated herein by reference in its entirety. However, it should be appreciated that the elbow assembly and mask vent thereof may be adapted for use with other suitable interface types. The elbow assembly 680 is structured to releasably engage a flange 617 surrounding the opening in the mask frame 610 of the mask system 600, e.g., with a snap-fit.

[127] Figs. 3-8-1 and 3-8-2 show an elbow assembly 780 and mask vent 740 according to another example of the present technology. In this example, the mask vent is integrally formed (e.g., molded) in one piece with the elbow assembly.

[128] As illustrated, the elbo assembly 780 includes a first end 781 structured to releasably engage with an opening in a mask frame and a second end 782 structured to releasably engage with an air delivery tube 798. In thi example, the interior of the elbow assembly is provided without a baffle. The mask vent provides inlet portion 744 with arcuate or angled side wall 745 to guide exhaust gas exiting from the first end 781 towards the vent, vent portion 746 including interior wall 749 with the plurality of vent holes 742, and outlet portion 748 including side wall 750 to diffuse vent flow and ensure gas is vented i a direction away from the mask system and the patient 1000 as described above. As illustrated, the side wall 750 includes a semi-circula configuration that overlaps with the cuff 799 of the air delivery tube 798 to establish the outlet portion 748 that surrounds the vent holes 742. [129] Figs. 3-9-1 and 3-9-2 show an elbow assembly 880 and mask vent 840 according to another example of the present technology. In this example, the vent holes 842 are provided to side wall 845 of the elbow assembly 880, and the outlet portion 848 including side wall 850 that surrounds the vent holes 842 is provided as a separate cover piece that is formed separately and attached to the side wall 845 of the elbow assembly 880, e.g., with a sna fit. In an example, the cover piece is provided as a retrofit to an existing elbow assembly. However, it should be appreciated that, the cover piece may be integrated or integrally formed in one- piece, e.g., co-molded, with the elbow assembly.

[ 130J In the illustrated example, the cover piece includes semi-circular arms or wings 852 extending from lateral sides of the side wall 850. The arms or wings 852 are resiliently flexible and structured to wrap around the perimeter of the elbo assembly t secure the cover piece in position.

[131] Figs. 3-10-1 and 3- 10-2 show an elbow assembly 980 and mask vent 940 according to another example of the present technology. In this example, the mask vent is integrally formed (e.g., molded) in one piece with the elbow assembly.

[1323 As illustrated, the elbo assembly 980 includes a first end 981 structured to releasabl engage with an open ng in a mask frame and a second end 982 structured to releasably engage with an air delivery tube. In this example, the interi r of the elbow assembly i provided without a baffle. The mask vent provides inlet portion 944 with .arcuate or angled side wall 945 to guide exhaust gas exiting from the first end 981 towards the vent, vent portion 946 including interior wall 94 with the plurality of vent holes 942. and outlet portion 948 including side wall 950 to diffuse vent flow and ensure gas is vented in a direction away from the mask system and the patient 1000 as described above. As illustrated, the side wall 950 is spaced from the second end 982 by support wall 983.

[133 j Figs. 3-1.1- 1 and 3- 11.-2 show an elbow assembly 1080 and mask vent 1040 according to another example of the present technology. In this example, the mask vent is integrally formed (e.g., molded) in one piece with the elbow ■assembly.

1134] As illustrated, the elbow assembly 1080 includes a first end 1081

structured to releasably engage with an opening in a mask frame and a second end 1082 structured to releasably engage with an air deli very tube, in this example, the axes of the vent holes 1042 and a longitudinal axis al of the outlet portion 1048 are aligned or parallel with a longitudinal axis a2 of the first end 108 i of the elbow assembly . As illustrated, the side wall 1050 of the outlet portion 1048 supports the vent wall 1049 with the plurality of vent holes 1042 within an interior of the elbow assembl , and the side wall 1050 overlaps with side walls of the elbow assembly 1080. In an alternative implementation, the side wall 1050 coincides with the side walls of the elbow assembly 1080. In other words, the side walls of the elbow assembly 1080 also serve as the side wall 1050 of the outlet portion 1048.

[135] Figs, 3-12-1 and 3-12-2 show an elbow assembly 1180 and mask vent 1140 according to another example of the present technology. In this example, the mask vent is integrally formed (e.g., molded) in one piece with the elbow assembly.

[ 136 j As illustrated, the elbo assembly 11 0 include a first end 1181

structured to releasably engage with an opening in a mask frame and a second end 1 182 structured to releasably engage with an air delivery tube. In thi s example, the mask vent 140 is provided on lateral sides of the elbow assembly. Each mask vent 1140 includes a recessed configuration with the side wall 1 150 of the outlet portion 1 148 supporting the vent wall 1 149 with the plurality of vent holes 1142 within an interior of the elbow assembly.

[137] Figs, 3-13-1 and 3-13- show an elbow assembly 1280 and mask vent 1240 according to another example of the present technology. In this example, the mask vent is integrall formed (e.g., molded) in one piece with the elbow assembly. [138] Similar to the example of Figs. .3-11-1 and 3-11-2, the axes of the vent holes 1242 and a longitudinal axis al of the outlet portio 1.248 are aligned or paral lel with a longitudinal xis a2 of the first end 1281 of the elbow assembly, and the side wall 1250 supports the vent wall 1.249 with the pluralit of vent holes 1242 within a interior of the elbow assembly. In this example, the side wall 1.250 extends further into the interior of the elbow assembly so as to define at least a portion of a baffle wall that separates the intake port and the exhaust port. As a further benefit of this extension, during inspiration, the Venturi effect results in a relatively low pressure zone around the venting holes and thus reduces the venting flow through the vent 1240 during inspiration. Conversely, during expiration, the Venturi effect results in enhanced gas washout.

8.3.5 Decoupling stracture(s) 3500

[ 1 9] In one form the patient interface 3000 includes at least one decoupling structure, for example a swivel . or a ball and socket,

8.3.6 Connection port 3600

[ 1403 Connection port 3600 allows for connection to the air circuit.

8.3.7 Forehead support 3700

[141] In. one form, the patient interface 3000 includes a forehead support 3700, e.g. see Fig. 3-7-5.

8.3.8 Anti-asphyxia valve 3800

[142] In one form, the patient interface 3000 includes an anti-asphyxia valve 3800.

8.3.9 Ports 3900

[143] In one form of the present technology, a patient interface 3000 includes one or more ports, that allow access to the volume within the plenum chamber 3200. In one form this allows a clinician to supply supplemental oxygen. In one form this allows for the direct measurement of a property of gases within the plenum chamber 3200, such as the pressure. 8.4 PAP DEVICE 4000

[144] A preferred PAP device 4000 in accordance with one aspect of the present technology comprises mechanical and pneumatic components 4100, electrical components 4200 and i programmed to execute one or more algorithms, An exemplary PAP device has an external housing 4010., formed in two parts, an upper portion 4012 of the external housing 4010, and a lower portion 4014 of the external housing 4010. I alternative forms, the external housing 4010 may include one or more panel(s) 4015. The PAP device 4000 may comprise a chassis 4016 that supports one or more internal components of the PA device 4000. In one form a pneumatic block 4020 is supported by , or formed as part of the chassis 4016. The PAP device 4000 ma include a handle 4018.

[145] The pneumatic path of the PAP device 4000 may comprise an inlet air filter 4112, an inlet muffler, a controllable pressure device capable of supplyin air at positive pressure (e.g., a blower 4142), and an outlet muffler. The pneumatic block 4020 may comprise a portion of the pneumatic path that i s located within the external housing 4010.

[146] The PAP device 4000 may have an electrical power supply 4210, and one or mote input devices 4220. Electrical components 4200 may be mounted on a single Printed Circuit Board Assembly (PCB A) 4202. In an alternative form, the PAP device 4000 may include more than one PC.BA 4202.

8.5 GLOSSARY

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

8,5.1 General

[ 148] Air: In certain forms of the present technology, air supplied to a patient may be atmospheric air, and in other forms of the present technology atmospheric air may be supplemented with oxygen. [149] Continuous Positive Airway Pressur (CPAP); CPAP treatment will be taken to mean the application of a supply of air or breathable gas to the entrance to the airways at a pressure that is continuously positive with respect to atmosphere, and preferably approximately constant through a respiratory cycle of a patient. In some forms, the pressure at the entrance to the airways will vary by a few centimetres of water within a single respiratory cycle, for exam le being higher during inhalation and lower during exhalation. 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 indicatio s of partial upper airway obstruction.

8.5,2 Aspects of PAP devices

[150] Air circuit: A conduit or tube constructed and arranged in use to deli ve a supply of air or breathable gas between a PAP device and a patient interface. In particular, the air circuit may be in fluid connection with the outlet of the pneu atic block and the patient interface. The air circuit may be referred to as air delivery tube. In some cases there may be separate limbs of the circuit for inhalation and exhalation, i other case a single limb is used.

[151] APAP: Automatic Positive Airway Pressure. Positive airway pressure that is continually adjustable between minimum and maximum limits, depending on the presence or absence of indications of SDB events.

[152] Blower or flow generator: A device that delivers a flow of air at pressure above ambient pressure.

[ 153] Controller: A device, o portion of a device that adjusts an output based on an input. For example one form of controller has a variable that is under control - the control variable - that constitutes the input to the device. The output of the device is a function of the current value of the control variable, and a set point for the variable. A servo-ventilator may include a controller that has ventilation as an input, a target ventilation as the set point, and level of pressure support as an output. Other forms of input may be one or more of oxygen saturation (Sa€)_), partial pies sure of carbon dioxide (PC0₂), movement, a signal from a photopiethysmogram, and peak flow. The set point of the controller may be one or more of fixed, variable or learned. For example, the set point in a ventilator may be a long term average, of the measured ventilation of a patient. Another ventilator may have a ventilation set point thai changes with time, A pressure controller may be configured to control a blower or pump to deliver air at a particular pressure,

[ 154] Therapy: Therapy in the present context may be one or more of positive pressure therapy, oxygen therapy, carbon dioxide therapy, control of dead space, and the administration of a drug.

[ 155] Positive Airway Pressure (PAP) device: A device for providing a suppl of air at positive pressure to the airways.

[156] Transducers A device for converting one form of energy or signal into another. A transducer may be a sensor or detector for con erting mechanical energy (such as movement) into an electrical signal. Examples of transducers include pressure sensors, flow sensors, carbon dioxide (CO?) sensors, oxygen (0₂) sensors, effort sensors, movement sensors, noise sensors, a plethysmograph, and cameras.

8,5.3 PAP device parameters

[ 157] flow rate: The instantaneous volume (or mass) of air delivered per unit time. While flow rate and ventilation have the same dimensions of volume or mass per unit time, flow rate is measured over a much shorter period of time. Flow may be nominally positive for the inspiratory portion of a breathing cycle of a patient, and hence negative for the expiratory portion of the breathi ng cycle of a patient. In some eases, a reference to flow rate will be a reference to a scalar quantity, namely a quantity having magnitude only, in other eases, a reference to flow rate will be a reference to a vector quantity, namely a quantity having both magnitude and direction. Flow will be given the symbol Q. Total flow, QL is the flow of air leaving the PAP device. Vent flow, Qv, is the flow of air leaving a vent to allow was out of exhaled gases. Leak flow, QL is the flow rale of unintentional leak from a patient interface system. Respiratory flow, Qr, is the flow of air that i received in o the patient's respiratory system,

1158] Leak: Preferably, the word leak will be taken to be a flow of air to the ambient. Leak may be intentional, for example to allow for the washout of exhaled 0¾. Leak may be unintentional, for example, as the result of an incomplete seal between a mask and a patient's face.

[159] Pressure: Force per unit area. Pressure may be measured in a range of units, including cml¾Q, g-f/cm², hectopascal. IcmHiO is equal to I g-f/cm² and is approximately 0.98 hectopascal. In this specification, unless otherwise stated, pressure is given in units of crnl¾0. For nasal CPAP treatment of OS A, a reference to treatment pressure is a reference to a pressure in the range of about 4- 20 cmHjO, or about 4-30 cm¾0. The pressure in the patient interface is given the symbol Pm.

1160] Sound Power: The energy per unit time carried by a sound wave. The sound power is proportional to the square of sound pressure multiplied by the area of the wavefront. Sound power is usually given in decibel SWL, that is, decibels relati e to a reference power, normally taken as 10^{" "} watt.

[ 161 ] Sound Pressure: The local deviation from ambient pressure at a given time instant as a result of a sound wave travelling through a medium, Sound pressure is usually given in decibels SPL, that is, decibels relative to a reference pressure, normally taken as 20 x 10 ⁶ pascal (Pa), considered the threshold of huma hearing.

8.5.4 Anatomy of the respiratory system

[162] Diaphragm: A sheet of muscle that extends across the bottom of the rib cage. The diaphragm separates the thoracic cavity, containing the heart, lungs and ribs, from the abdominal cavity, As the diaphragm contracts the volume of the thoracic cavity increases and air is drawn into the lungs. [163] Larynx: The larynx, or voiee box houses the vocal folds and connects the inferior part of the pharynx (hypopharynx) with the trachea.

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

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

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

8.5.5 Materials

[167. J 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 SILASTI (included in the range of products sold under this trademark), manufactured by Dow Corning, Another manufacture of LSR is W acker. Unless otherwise specified to the contrary, a preferred form of LSR has a Shore A (or Type A) indentation hardness in the range of about 35 to about 45 as measured using ASTM D2240,

[168] Polycarbonate: typically transparent thermoplastic polymer of

Bisphenol-A Carbonate. 8,5.6 Aspects of a patient interface

[169] Anti-asphyxia valve (AA V): The component or sub-assembly of a mask system that, by opening to atmosphere in a failsafe manner, reduces the risk of excessive CCh rebreathing by a patient.

1170] Elbow: A conduit that directs an axis of flow of air to change direction through an angle. In one form, the angle may be approximately 90 degrees. In another form, the angle may be less than 90 degrees. The conduit may have an approximately circular cross-section, h another form the conduit may have an oval or rectangular cross- sect ion.

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

[ 172] Headgear: Headgear will be taken to mean a form of positioning and stabilizing structure designed for use o a head. Preferably the headgear comprises a collection of one or more struts, ties and stiffeners configured to locate and retain a patient interface in position on a patient's face for delivery of respirator therapy. Some ties are formed of a soft, flexible, elastic material such as laminated composite of foam and fabric.

[173] Membrane: Membrane will be taken to mean a typically thin element that has, preferably, substantially no resistance to bending, but has resistance to being stretched.

[174] Plenum chambe a mask plenum chamber will be taken to a mean portion of a patient interface having walls enclosing a volume of space, the volume having air therein pressurised above atmospheric pressure in use. A shell may form part of the walls of a mask plenum chamber. In one form, a region of the patien t's face forms one of the lls of the plenum chamber. [175] Seat The noun form ("a seal") will be taken to mean a structure or barrier that intentionally resists the flow of air through the interface of two surfaces. The verb form ("to sea ') will be taken to mean to resist a flow of air,

1176] Shell: A shell will preferably be taken to mean a curved structure having bending, tensile and compressive stiffness, for example, a portion of a mask that forms a curved structural wall of the mask. Preferably, compared to its overall dimensions it is relatively thin. In some forms, a shell may be faceted. Preferably such walls are airtight, although i some forms they may not be airtight.

1177] Stiff enen A stiff ener will be taken to mean a structural component

designed to increase the bending resistance of another component in at least one direction,

[178 J Strut: A strut will be taken to be a structural component designed to

increase the compression resistance of another component in at least one direction.

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

[180] Tie: A tie will be taken to be a structural component designed to resist tension.

1.181] Vent: (noun) the structure that allows a deliberate controlled rate leak of air from an interior of the ma sk, or conduit to ambient air, to allow washout of exhaled carbon dioxide (C⁽¾) a d supply of oxyge (O r).

8.5.7 Terms used in relation to patient interface

[182] Curvature (of a surface) A region of a surface-having a saddle shape, which curves up in one direction and curves down in a different direction, will be said to have a negative curvature. A region of a surface having a dome shape, w ich curves the same way in two principle directions, will be said to have a positive curvature. A flat surface will be taken to have zero curvature,

[183] Floppy: A quality of a material, structure or composite that, is the

combination of features of:

• Readily conforming to finger pressure.

• Unable to retain its shape when caused to support, its own weight.

• Not rigid.

• Able to be stretched or bent elastically with little effort,

[184] The quality of being floppy may have an associated direction, hence a particular material, structure or composite may be floppy in a first direction, but stiff or rigid in a second direction, for example a second direction that is orthogonal to the first direction.

[185] Resilient. Able to deform substantially elastically, and t release

substantially all of the energy upon unloading, within a relativel short period of time such as 1 second.

1186] Rigid: Not readily deforming to finger pressure, and/or the tensions or loads typically encountered when setting up and maintaining a patient interface in sealing relationship with an entrance to a patient's airways.

[187] Semi-rigid: means being sufficiently rigid to not substantially distort under the effects of mechanical forces typically applied during positive airway pressure therapy;

8.6 OTHER REMARKS

[188] 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 the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. [189] Unless the context clearly dictates otherwise and where a range of values is provided, it is understood that eac intervening value, to the tenth of the unit of the lower limit, between the upper and tower 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 inciudes one or bot of the limits, ranges excluding either or both of those included limits are also included in the technology.

[190] Furthermore, where a value or values are stated herein as being

implemented as pail of the technology, it is understood that such values may be approximated, unless otherwise stated, and such values may be utilized t any suitable significant digit to the extent that a practical technical implementation may permit or require it .

[1 1] 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 he used in the practice or testing of the present technology, a limited number of the exemplary methods and materials are described herein,

[192] When a particular material is identified as being preferably 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.

[193] 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.

[ 194] All publications mentioned herein are incorporated by reference t

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 pubiication dates, which may need to be independently confirmed.

[195] Moreover, in interpretin the disclosure, all terms should be interpreted in the broadest reasonable manner consistent with the context. In particular, 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.

[1 6] 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.

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

[198 J It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements maybe devised without departing from the spirit and scope of the technology. REFERENCE SIGNS LIST

100 mask system

110 mask frame

112 opening

115 exterior surface

120 patient contacting portion

130 shroud

132 opening

134 opening

140 mask vent

141 venting area

142 vent hole

150 continuous side waif

241 venting area

242 vent hole

250 side wall

341 venting area

342 vent hole

350 side wall

441 venting area

442 vent hole

445 rib

450 side wall

540 mask vent

542 vent hole

544 inlet portion

545 side wall

546 vent portion

548 outlet portion

54S interior wall

550 side wall

580 elbow assembly

581 first end

582 second end

583 collar

584 baffle

590 intake port

592 exhaust port

600 mask system

610 mask frame

617 flange

620 cushion

625 forehead support

640 vent cap vent hole main body inlet portion side wall vent portion support wail wall portion wall portion outlet portion interior wall side wall engagement ring groove groove entry opening elbow assembly first end second end baffle flange annular wall intake port exhaust port mask vent vent hole inlet portion side wall vent portion outlet portion interior wall side wall elbow assembly first end second end air delivery tube cuff mask vent vent hole side wall outlet portion side wall wing elbow assembly mask vent vent hole 945 side wail

946 vent portion

948 outlet portion

949 interior wall

950 side wail

980 elbow assembly

981 first end

982 second end

983 support wall

1000 patient

1040 mask vent

1042 vent hole

1048 outlet portion

1049 vent wall

1050 side wall

1080 elbow assembly

1081 first end

1082 second end

1100 partner

1140 mask vent

1142 vent hole

1148 outlet portion

1149 vent wall

1150 side wail

1180 elbow assembly

1181 first end

1182 second end

1240 vent

1242 vent hole

1248 outlet portion

1249 vent wall

1250 side wail

1280 elbow assembly

1281 first end

3000 patient interface

3100 seal-forming structure

3110 sealing flange

3120 support flange

3200 plenum chamber

3300 stabilising structure

3400 vent

3500 decou ling structure

3600 connection port

3700 forehead support

3800 anti-asphyxia valve 3900 port

4000 PAP device

4010 external housing

4012 upper portion

4014 portion

4015 panel

4016 chassis

4018 handle

4020 pneumatic block

4100 pneumatic component

4112 inlet air filter

4142 blower

4170 air circuit

4200 electrical component

4202 board assembly

4210 electrical power supply

4220 input device

5000 humidifier

Claims

9 CLAIMS

1. A vent arrangement for a mask system, comprising; a mask component; and a mask vent provided to the mask component, the mask vent including: a plurality of vent holes each extending through a thickness of the mask component and each including a vent exit, and a continuous side wall structured to surround the plurality of vent exits of the vent holes,

2. A vent arrangement according to claim 3 , wherein the side wall extends in a direction of the vent airflow.

3. A vent arrangement according to any one of claims 1 to 2, wherein the side wall includes a uniform or constant height along its perimeter.

4. A vent arrangement according to any one of claims 1 to 3, wherein the side wall includes a uniform or constant thickness along its perimeter.

5. A vent arrangement according to any one of claims 1 to 4, wherein the vent holes are arranged in columns.

6. A vent arrangement according to any one of claims 1 to 5,. wherein the vent holes are arranged to provide a venting area, and the side wall is structured to surround the entire venting area.

?. A vent arrangement according to claim 6, wherein the side wall includes a generally similar shape to the venting area.

8. A vent arrangement according to any one of claims 6 to 7, further comprising a. plurality of interior wall or ribs within the side wall and structured to extend at least partially through the venting area.

9. A vent arrangement according to any one of claim 1 to 8,. wherein each vent hole includes a generally part conic shape.

10. A vent arrangement according to any one of claims 1 to 8,. wherein each vent hole includes a generally cylindrical shape.

11. A vent arrangement according to any one of claims 1 to 10, wherein the mask component is a mask frame.

12 , A vent arrangement according to any one of claims 1 to 10, wherein the mask component is an elbow assembly.

13. A vent arrangement according to claim 12, wherein the mask vent is integrally formed in one piece with the elbow assembly.

14. A vent arrangement according to claim 12, wherein at least a portion of the mask vent is formed separately from the elbow assembly and attached thereto.

15. A vent arrangement accordin to claim 14, wherein the- mask vent is a vent cap structured to attach to the elbow assembly.

16. A vent arrangement according to claim 3 , wherein the vent holes are provided to the elbow assembl and the side wall i provided as a cover piece structured to attac to the elbow assembly.

.

17. A vent arrangement according to any one of claims 12 to 16, wherein the elbow includes a baffle that _.separates an intake port- from an exhaust port, and the mask vent is provided at an outlet of the exhaust port.

18. A vent arrangement according to any one of claims 1 to 17, wherein the mask vent is recessed within an interior of the- mask system.

19. A mask system comprising-: a frame; a cushion provided to the frame and adapted to form a seal with a patient's nose and/or mouth; an. elbow assembly provided to the frame and adapted to be connected to an air delivery tube that delivers breathable gas t the patient: and a mask vent including a plurality of vent holes each extending through a thickness of the frame and each includin a vent exit, and a continuous side wall structured to surround the plurality of vent exits of the vent holes.

20. A mask system comprising: a frame; a cushion provided to the frame mid adapted to form a seal with a patient's nose and/or mouth; an elbow assembly provided to the frame and adapted to be connected to an air delivery tube that delivers breathable gas to the patient; and a mask vent including a plurality of vent holes each extending through a thickness of the elbow assembly and each including a vent exit, and a continuous side wall structured to surround the plurality of vent exits of the vent holes.

21. A mask system according to claim 20, wherein the mask vent is integrally formed with the elbow assembly.

22. A mask system according to claim 20, wherein the mask vent is recessed within an interior of the elbow assembly.

23. A mask vent including: an, interior wall extending transversely across a vent portion of the mask vent; a plurality of vent holes each extending through a thickness of the interior wall and each including a vent exit; and a continuous side wall structured to surround the plurality of vent exits of the vent holes,

wherein the -mask vent is. structured, to he attached to an elbo w assembly of a mask system..