Patent Application
20230263985
The present technology relates to one or more of the screening, diagnosis, monitoring, treatment, prevention and amelioration of respiratory-related disorders. The present technology also relates to medical devices or apparatus, and their use.
The respiratory system of the body facilitates gas exchange. The nose and mouth form the entrance to the airways of a patient.
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.
A range of respiratory disorders exist. Certain disorders may be characterised by particular events, e.g. apneas, hypopneas, and hyperpneas.
Examples of respiratory disorders include Obstructive Sleep Apnea (OSA), Cheyne-Stokes Respiration (CSR), respiratory insufficiency, Obesity Hyperventilation Syndrome (OHS), Chronic Obstructive Pulmonary Disease (COPD), Neuromuscular Disease (NMD) and Chest wall disorders.
Obstructive Sleep Apnea (OSA), a form of Sleep Disordered Breathing (SDB), is characterised by events including occlusion or obstruction of the upper air passage during sleep. It results from a combination of an abnormally small upper airway and the normal loss of muscle tone in the region of the tongue, soft palate and posterior oropharyngeal wall during sleep. The condition causes the affected patient to stop breathing for periods typically of 30 to 120 seconds in duration, sometimes 200 to 300 times per night. It often causes excessive daytime somnolence, and it may cause cardiovascular disease and brain damage. The syndrome is a common disorder, particularly in middle aged overweight males, although a person affected may have no awareness of the problem. See U.S. Pat. No. 4,944,310 (Sullivan).
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. See U.S. Pat. No. 6,532,959 (Berthon-Jones).
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.
A patient with respiratory insufficiency (a form of respiratory failure) may experience abnormal shortness of breath on exercise.
Obesity Hyperventilation 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.
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.
Neuromuscular Disease (NMD) is a broad term that encompasses many diseases and ailments that impair the functioning of the muscles either directly via intrinsic muscle pathology, or indirectly via nerve pathology. Some NMD patients are characterised by progressive muscular impairment leading to loss of ambulation, being wheelchair-bound, swallowing difficulties, respiratory muscle weakness and, eventually, death from respiratory failure. Neuromuscular disorders can be divided into rapidly progressive and slowly progressive: (i) Rapidly progressive disorders: Characterised by muscle impairment that worsens over months and results in death within a few years (e.g. Amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers); (ii) Variable or slowly progressive disorders: Characterised by muscle impairment that worsens over years and only mildly reduces life expectancy (e.g. Limb girdle, Facioscapulohumeral and Myotonic muscular dystrophy). Symptoms of respiratory failure in NMD include: increasing generalised weakness, dysphagia, dyspnea on exertion and at rest, fatigue, sleepiness, morning headache, and difficulties with concentration and mood changes.
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.
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.
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.
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).
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.
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.
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 is 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's anatomical 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.
Another form of flow therapy is long-term oxygen therapy (LTOT) or supplemental oxygen therapy. Doctors may prescribe a continuous flow of oxygen enriched gas 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.
For certain patients, oxygen therapy may be combined with a respiratory pressure therapy or HFT by adding supplementary oxygen to the pressurised flow of air. When oxygen is added to respiratory pressure therapy, this is referred to as RPT with supplementary oxygen. When oxygen is added to HFT, the resulting therapy is referred to as HFT with supplementary oxygen.
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.
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.
Another form of therapy system is a mandibular repositioning device.
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 cmH2O 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 cmH2O. 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.
Certain other mask systems may be functionally unsuitable for the present field. For example, purely ornamental masks may be unable to maintain a suitable pressure. Mask systems used for underwater swimming or diving may be configured to guard against ingress of water from an external higher pressure, but not to maintain air internally at a higher pressure than ambient.
Certain masks may be clinically unfavourable for the present technology e.g. if they block airflow via the nose and only allow it via the mouth.
Certain masks may be uncomfortable or impractical for the present technology if they require a patient to insert a portion of a mask structure in their mouth to create and maintain a seal via their lips.
Certain masks may be impractical for use while sleeping, e.g. for sleeping while lying on one's side in bed with a head on a pillow.
The design of a patient interface presents a number of challenges. The face has a complex three-dimensional shape. The size and shape of noses and heads varies considerably between individuals. Since the head includes bone, cartilage and soft tissue, different regions of the face respond differently to mechanical forces. The jaw or mandible may move relative to other bones of the skull. The whole head may move during the course of a period of respiratory therapy.
As a consequence of these challenges, some masks suffer from being one or more of obtrusive, aesthetically undesirable, costly, poorly fitting, difficult to use, and uncomfortable especially when worn for long periods of time or when a patient is unfamiliar with a system. Wrongly sized masks can give rise to reduced compliance, reduced comfort and poorer patient outcomes. Masks designed solely for aviators, masks designed as part of personal protection equipment (e.g. filter masks), SCUBA masks, or for the administration of anaesthetics may be tolerable for their original application, but nevertheless such masks may be undesirably uncomfortable to be worn for extended periods of time, e.g., several hours. This discomfort may lead to a reduction in patient compliance with therapy. This is even more so if the mask is to be worn during sleep.
CPAP therapy is highly effective to treat certain respiratory disorders, provided patients comply with therapy. If a mask is uncomfortable, or difficult to use a patient may not comply with therapy. Since it is often recommended that a patient regularly wash their mask, if a mask is difficult to clean (e.g., difficult to assemble or disassemble), patients may not clean their mask and this may impact on patient compliance.
While a mask for other applications (e.g. aviators) may not be suitable for use in treating sleep disordered breathing, a mask designed for use in treating sleep disordered breathing may be suitable for other applications.
For these reasons, patient interfaces for delivery of CPAP during sleep form a distinct field.
Patient interfaces may include a seal-forming structure. Since it is in direct contact with the patient's face, the shape and configuration of the seal-forming structure can have a direct impact the effectiveness and comfort of the patient interface.
A patient interface may be partly characterised according to the design intent of where the seal-forming structure is to engage with the face in use. In one form of patient interface, a seal-forming structure may comprise a first sub-portion to form a seal around the left naris and a second sub-portion to form a seal around the right naris. In one form of patient interface, a seal-forming structure may comprise a single element that surrounds both nares in use. Such single element may be designed to for example overlay an upper lip region and a nasal bridge region of a face. In one form of patient interface a seal-forming structure may comprise an element that surrounds a mouth region in use, e.g. by forming a seal on a lower lip region of a face. In one form of patient interface, a seal-forming structure may comprise a single element that surrounds both nares and a mouth region in use. These different types of patient interfaces may be known by a variety of names by their manufacturer including nasal masks, full-face masks, nasal pillows, nasal puffs and oro-nasal masks.
A seal-forming structure that may be effective in one region of a patient's face may be inappropriate in another region, e.g. because of the different shape, structure, variability and sensitivity regions of the patient's face. For example, a seal on swimming goggles that overlays a patient's forehead may not be appropriate to use on a patient's nose.
Certain seal-forming structures may be designed for mass manufacture such that one design fit and be comfortable and effective for a wide range of different face shapes and sizes. To the extent to which there is a mismatch between the shape of the patient's face, and the seal-forming structure of the mass-manufactured patient interface, one or both must adapt in order for a seal to form.
One type of seal-forming structure extends around the periphery of the patient interface, and is intended to seal against the patient's face when force is applied to the patient interface with the seal-forming structure in confronting engagement with the patient's face. The seal-forming structure may include an air or fluid filled cushion, or a moulded or formed surface of a resilient seal element made of an elastomer such as a rubber. With this type of seal-forming structure, if the fit is not adequate, there will be gaps between the seal-forming structure and the face, and additional force will be required to force the patient interface against the face in order to achieve a seal.
Another type of seal-forming structure incorporates a flap seal of thin material positioned about the periphery of the mask so as to provide a self-sealing action against the face of the patient when positive pressure is applied within the mask. Like the previous style of seal forming portion, if the match between the face and the mask is not good, additional force may be required to achieve a seal, or the mask may leak. Furthermore, if the shape of the seal-forming structure does not match that of the patient, it may crease or buckle in use, giving rise to leaks.
Another type of seal-forming structure may comprise a friction-fit element, e.g. for insertion into a naris, however some patients find these uncomfortable.
Another form of seal-forming structure may use adhesive to achieve a seal. Some patients may find it inconvenient to constantly apply and remove an adhesive to their face.
A range of patient interface seal-forming structure technologies are disclosed in the following patent applications, assigned to ResMed Limited: WO 1998/004,310; WO 2006/074,513; WO 2010/135,785.
One form of nasal pillow is found in the Adam Circuit manufactured by Puritan Bennett. Another nasal pillow, or nasal puff is the subject of U.S. Pat. No. 4,782,832 (Trimble et al.), assigned to Puritan-Bennett Corporation.
ResMed Limited has manufactured the following products that incorporate nasal pillows: SWIFT™ nasal pillows mask, SWIFT™ II nasal pillows mask, SWIFT™ LT nasal pillows mask, SWIFT™ FX nasal pillows mask and MIRAGE LIBERTY™ full-face mask. The following patent applications, assigned to ResMed Limited, describe examples of nasal pillows masks: International Patent Application WO2004/073,778 (describing amongst other things aspects of the ResMed Limited SWIFT™ nasal pillows), US Patent Application 2009/0044808 (describing amongst other things aspects of the ResMed Limited SWIFT™ LT nasal pillows); International Patent Applications WO 2005/063,328 and WO 2006/130,903 (describing amongst other things aspects of the ResMed Limited MIRAGE LIBERTY™ full-face mask); International Patent Application WO 2009/052,560 (describing amongst other things aspects of the ResMed Limited SWIFT™ FX nasal pillows).
A seal-forming structure of a patient interface used for positive air pressure therapy is subject to the corresponding force of the air pressure to disrupt a seal. Thus a variety of techniques have been used to position the seal-forming structure, and to maintain it in sealing relation with the appropriate portion of the face.
One technique is the use of adhesives. See for example US Patent Application Publication No. US 2010/0000534. However, the use of adhesives may be uncomfortable for some.
Another technique is the use of one or more straps and/or stabilising harnesses. Many such harnesses suffer from being one or more of ill-fitting, bulky, uncomfortable and awkward to use.
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.
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.
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. Humidifiers therefore often have the capacity to heat the flow of air was well as humidifying it.
Some forms of treatment systems may include a vent to allow the washout of exhaled carbon dioxide. The vent may allow a flow of gas from an interior space of a patient interface, e.g., the plenum chamber, to an exterior of the patient interface, e.g., to ambient.
The vent may comprise an orifice and gas may flow through the orifice in use of the mask. Many such vents are noisy. Others may become blocked in use and thus provide insufficient washout. Some vents may be disruptive of the sleep of a bed partner 1100 of the patient 1000, e.g. through noise or focussed airflow.
ResMed Limited has developed a number of improved mask vent technologies. See International Patent Application Publication No. WO 1998/034,665; International Patent Application Publication No. WO 2000/078,381; U.S. Pat. No. 6,581,594; US Patent Application Publication No. US 2009/0050156; US Patent Application Publication No. 2009/0044808.
Sound pressure values of a variety of objects are listed below
The present technology is directed towards providing medical devices used in the screening, diagnosis, monitoring, amelioration, treatment, or prevention of respiratory disorders having one or more of improved comfort, cost, efficacy, ease of use and manufacturability.
A first aspect of the present technology relates to apparatus used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respiratory disorder.
Another aspect of the present technology relates to methods used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respiratory disorder.
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.
An aspect of the present technology provides a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas to a patient.
An aspect of the present technology provides a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas to a patient, the connection member comprising a vent for venting gas exhaled by the patient to the ambient air and an anti-asphyxia valve (AAV).
An aspect of the present technology provides a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas to a patient, the connection member comprising a vent for venting gas exhaled by the patient to the ambient air and an anti-asphyxia valve (AAV), wherein in use the AAV is located closer to the patient than the vent.
An aspect of the present technology provides a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas to a patient, the connection member comprising a vent for venting gas exhaled by the patient to the ambient air and an anti-asphyxia valve (AAV), wherein the connection member is substantially straight and/or is compact in size.
An aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient-proximal end configured to connect to the patient interface and having a patient-distal end, the first tube portion having a first longitudinal central axis that is substantially straight between the patient-proximal end and the patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, the second tube portion having a second longitudinal central axis that is substantially straight between the patient-proximal end and the patient-distal end, wherein the first tube portion and the second tube portion are arranged with the first longitudinal central axis of the first tube portion substantially parallel to the second longitudinal central axis of the second tube portion and at least a portion of the patient-proximal end of the second tube portion positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion; and
an anti-asphyxia valve (AAV) comprising an opening to the ambient air and a closure configured to move between a first position in which the closure covers the opening and a second position in which the opening is uncovered.
In examples: a) the AAV is located in a position on the connection member closer to the patient-proximal end of the first tube portion than the vent; b) the AAV is located proximate the patient-proximal end of the first tube portion; c) the vent is located proximate the patient-distal end of the first tube portion; d) the closure comprises a hingedly mounted flap; e) the flap is mounted to the first tube portion; f) the flap comprises a base portion configured to fit into a first aperture in the first tube portion; g) the base portion is configured to fit into the first aperture via a snap-fit connection; h) the opening is positioned to face an anterior direction when in use; i) the connection member further comprises a tube connector configured to connect the second tube portion to an outer surface of the first tube portion; j) the tube connector comprises a third tube portion mounted to an outer surface of the second tube portion, wherein the third tube portion surrounds the patient-distal end of the first tube portion; k) the first tube portion comprises a connecting portion configured to fit into a second aperture in the third tube portion; l) the third tube portion comprises a connecting portion configured to fit into a second aperture in the first tube portion; m) the connecting portion fits into the second aperture via a snap-fit connection; n) the vent comprises a plurality of vent slots arranged in a region between the first tube portion and the second tube portion; o) the plurality of vent slots are arranged around the second tube portion; p) the vent slots are formed between a plurality of ribs extending between an outer surface of the second tube portion and an inner surface of the first tube portion; q) the vent comprises four vent slots; r) the plurality of vent slots are equally spaced apart; s) a plane of the patient-proximal end of the first tube portion is arranged at a substantially non-perpendicular angle to the first longitudinal central axis; t) the plane of the patient-proximal end of the first tube portion is angled with respect to the first longitudinal central axis so that, in use, the connection member is directed in an anterior-inferior direction; u) the first tube portion is cylindrical in shape; v) the second tube portion is cylindrical in shape; w) the vent slots are arranged around an annular region between the first and second tube portions; x) the first longitudinal central axis and the second longitudinal central axis are axially aligned; y) when the closure is in the second position, the closure substantially covers the patient-proximal end of the second tube portion thereby preventing flow of gas between the first tube portion and the second tube portion during use; z) in the second position the hingedly mounted flap contacts the patient-proximal end of the second tube portion; and/or aa) the patient-proximal end of the second tube portion is at a second tube angle to the second longitudinal central axis and, when the hingedly mounted flap contacts the patient-proximal end of the second tube portion, the hingedly mounted flap is oriented at substantially the second tube angle to the second longitudinal central axis, the second tube angle being substantially non-perpendicular.
Another aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient-proximal end configured to connect to the patient interface and having a patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, wherein at least a portion of the patient-proximal end of the second tube portion is positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion; and
an anti-asphyxia valve (AAV) comprising an opening to the ambient air and a closure configured to move between a first position in which the closure covers the opening and a second position in which the opening is uncovered;
wherein the AAV is located in a position on the connection member closer to the patient interface than the vent.
In examples: a) the AAV is located proximate the patient-proximal end of the first tube portion; b) the closure comprises a hingedly mounted flap; c) the flap is mounted to the first tube portion; d) the flap comprises a base portion configured to fit into a first aperture in the first tube portion; e) the base portion is configured to fit into the first aperture via a snap-fit connection; f) the opening is positioned to face an anterior direction when in use; g) the connection member further comprises a tube connector configured to connect the second tube portion to an outer surface of the first tube portion; h) the tube connector comprises a third tube portion mounted to an outer surface of the second tube portion, wherein the third tube portion surrounds the patient-distal end of the first tube portion; i) the first tube portion comprises a connecting portion configured to fit into a second aperture in the third tube portion; j) the third tube portion comprises a connecting portion configured to fit into a second aperture in the first tube portion; k) the connecting portion fits into the second aperture via a snap-fit connection; l) the vent comprises a plurality of vent slots arranged in a region between the first tube portion and the second tube portion; m) the plurality of vent slots are arranged around the second tube portion; n) the vent slots are formed between a plurality of ribs extending between an outer surface of the second tube portion and an inner surface of the first tube portion; o) the vent comprises four vent slots; p) the plurality of vent slots are equally spaced apart; q) a plane of the patient-proximal end of the first tube portion is arranged at a substantially non-perpendicular angle to the first longitudinal central axis; r) the plane of the patient-proximal end of the first tube portion is angled with respect to the first longitudinal central axis so that, in use, the connection member is directed in an anterior-inferior direction; s) the first tube portion is cylindrical in shape; t) the second tube portion is cylindrical in shape; u) the vent slots are arranged around an annular region between the first and second tube portions; v) the first longitudinal central axis and the second longitudinal central axis are axially aligned; w) when the closure is in the second position, the closure substantially covers the patient-proximal end of the second tube portion thereby preventing flow of gas between the first tube portion and the second tube portion during use; x) in the second position the hingedly mounted flap contacts the patient-proximal end of the second tube portion; and/or y) the patient-proximal end of the second tube portion is at a second tube angle to the second longitudinal central axis and, when the hingedly mounted flap contacts the patient-proximal end of the second tube portion, the hingedly mounted flap is oriented at substantially the second tube angle to the second longitudinal central axis, the second tube angle being substantially non-perpendicular.
Another aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient proximal end configured to connect to the patient interface and having a patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, wherein at least a portion of the patient-proximal end of the second tube portion is positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion; and
an AAV comprising an opening to the ambient air and a closure configured to move between a first position in which the closure covers the opening and a second position in which the opening is uncovered;
wherein the connection member has a substantially straight central longitudinal axis.
Another aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient proximal end configured to connect to the patient interface and having a patient-distal end, the first tube portion having a first longitudinal central axis that is substantially straight between the patient-proximal end and the patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, the second tube portion having a second longitudinal central axis that is substantially straight between the patient-proximal end and the patient end, wherein at least a portion of the patient-proximal end of the second tube portion is positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion; and
an AAV comprising an opening to the ambient air and a closure configured to move between a first position in which the closure covers the opening and a second position in which the opening is uncovered;
wherein the first longitudinal central axis passes through an opening of the second tube portion and the second longitudinal central axis passes through an opening of the first tube portion.
Another aspect of one form of the present technology is an air circuit assembly configured to fluidly connect a respiratory therapy device to a patient interface, the air circuit assembly comprising
an air circuit; and
a connection member as described in any one of the other aspects of the technology above.
Another aspect of one form of the present technology is a patient interface assembly comprising:
a connection member as described in any one of the other aspects of the technology above; and
a patient interface, comprising:
a plenum chamber pressurisable to a therapeutic pressure of at least 6 cmH2O above ambient air pressure, said plenum chamber including a plenum chamber inlet port sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient; and
a seal-forming structure constructed and arranged to form a seal with a region of the patient's face surrounding an entrance to the patient's airways, said seal-forming structure having 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 constructed and arranged to maintain said therapeutic pressure in the plenum chamber throughout the patient's respiratory cycle in use.
In examples: a) the plenum chamber is formed from a flexible material; b) the plenum chamber is formed from silicone; c) the seal-forming structure is configured to form a seal around both the patient's nose and mouth in use; d) the seal-forming structure is configured to form a seal over the bridge of the patient's nose in use; e) the seal-forming structure comprises an oral portion and a nasal portion; f) the nasal portion comprises a lip superior portion which contacts the lip superior of the patient in use; g) the nasal portion comprises a superior-facing medial portion which contacts the inferior and partially anterior surfaces of the patient's pronasale in use; h) the oral portion comprises a lip inferior portion which contacts the chin region of the patient in use; and/or i) the oral portion comprises an oral hole peripheral portion which contacts the cheeks of the patient in use.
An aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient-proximal end configured to connect to the patient interface and having a patient-distal end, the first tube portion having a first longitudinal central axis that is substantially straight between the patient-proximal end and the patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, the second tube portion having a second longitudinal central axis that is substantially straight between the patient-proximal end and the patient-distal end, wherein the first tube portion and the second tube portion are arranged with the first longitudinal central axis of the first tube portion substantially parallel to the second longitudinal central axis of the second tube portion and at least a portion of the patient-proximal end of the second tube portion positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
an anti-asphyxia valve (AAV) comprising an opening to the ambient air and a closure configured to move between a first position in which the closure covers the opening and a second position in which the opening is uncovered;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion; wherein the vent comprises a vent structure comprising:
An aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient-proximal end configured to connect to the patient interface and having a patient-distal end, the first tube portion having a first longitudinal central axis that is substantially straight between the patient-proximal end and the patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, the second tube portion having a second longitudinal central axis that is substantially straight between the patient-proximal end and the patient-distal end, wherein the first tube portion and the second tube portion are arranged with the first longitudinal central axis of the first tube portion substantially parallel to the second longitudinal central axis of the second tube portion and at least a portion of the patient-proximal end of the second tube portion positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
an anti-asphyxia valve (AAV) comprising an opening to the ambient air and a closure configured to move between a first position in which the closure covers the opening and a second position in which the opening is uncovered;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion; wherein the vent comprises a vent structure comprising:
a plurality of deflectors configured to deflect the air flow through each vent slot towards a part of the vent housing and/or another component in the respiratory system.
An aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient-proximal end configured to connect to the patient interface and having a patient-distal end, the first tube portion having a first longitudinal central axis that is substantially straight between the patient-proximal end and the patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, the second tube portion having a second longitudinal central axis that is substantially straight between the patient-proximal end and the patient-distal end, wherein the first tube portion and the second tube portion are arranged with the first longitudinal central axis of the first tube portion substantially parallel to the second longitudinal central axis of the second tube portion and at least a portion of the patient-proximal end of the second tube portion positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
an anti-asphyxia valve (AAV) comprising an opening to the ambient air and a closure configured to move between a first position in which the closure covers the opening and a second position in which the opening is uncovered;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion; wherein the vent comprises a vent structure comprising:
a vent housing defining a plurality of vent slots, the vent slots comprising:
Another aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient-proximal end configured to connect to the patient interface and having a patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, wherein at least a portion of the patient-proximal end of the second tube portion is positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion; wherein the vent comprises a vent structure comprising:
wherein the connection member further comprises an anti-asphyxia valve (AAV) comprising an opening to the ambient air and a closure configured to move between a first position in which the closure covers the opening and a second position in which the opening is uncovered;
wherein the AAV is located in a position on the connection member closer to the patient interface than the vent.
Another aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient-proximal end configured to connect to the patient interface and having a patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, wherein at least a portion of the patient-proximal end of the second tube portion is positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion; wherein the vent comprises a vent structure comprising:
a plurality of deflectors configured to deflect the air flow through each vent slot towards a part of the vent housing and/or another component in the respiratory system; and
wherein the connection member further comprises an anti-asphyxia valve (AAV) comprising an opening to the ambient air and a closure configured to move between a first position in which the closure covers the opening and a second position in which the opening is uncovered;
wherein the AAV is located in a position on the connection member closer to the patient interface than the vent.
Another aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient-proximal end configured to connect to the patient interface and having a patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, wherein at least a portion of the patient-proximal end of the second tube portion is positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion; wherein the vent comprises a vent structure comprising:
Another aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient proximal end configured to connect to the patient interface and having a patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, wherein at least a portion of the patient-proximal end of the second tube portion is positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion, the vent comprising a vent structure comprising:
wherein the connection member further comprises an AAV comprising an opening to the ambient air and a closure configured to move between a first position in which the closure covers the opening and a second position in which the opening is uncovered;
wherein the connection member has a substantially straight central longitudinal axis.
Another aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient proximal end configured to connect to the patient interface and having a patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, wherein at least a portion of the patient-proximal end of the second tube portion is positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion, the vent comprising a vent structure comprising:
a plurality of deflectors configured to deflect the air flow through each vent slot towards a part of the vent housing and/or another component in the respiratory system; and
wherein the connection member further comprises an AAV comprising an opening to the ambient air and a closure configured to move between a first position in which the closure covers the opening and a second position in which the opening is uncovered;
wherein the connection member has a substantially straight central longitudinal axis.
Another aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient proximal end configured to connect to the patient interface and having a patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, wherein at least a portion of the patient-proximal end of the second tube portion is positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion, the vent comprising a vent structure comprising:
a vent housing defining a plurality of vent slots, the vent slots comprising:
a vent inlet configured to receive an air flow; and
a vent outlet configured to allow the air flow to exit into the surrounding ambient air; and
a projecting portion structured and arranged to inhibit generation of flow layer instabilities, the projecting portion extending outwardly from the vent outlet; and
wherein the connection member further comprises an AAV comprising an opening to the ambient air and a closure configured to move between a first position in which the closure covers the opening and a second position in which the opening is uncovered;
wherein the connection member has a substantially straight central longitudinal axis.
Another aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient proximal end configured to connect to the patient interface and having a patient-distal end, the first tube portion having a first longitudinal central axis that is substantially straight between the patient-proximal end and the patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, the second tube portion having a second longitudinal central axis that is substantially straight between the patient-proximal end and the patient end, wherein at least a portion of the patient-proximal end of the second tube portion is positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion, the vent comprising a vent structure comprising:
wherein the connection member further comprises an AAV comprising an opening to the ambient air and a closure configured to move between a first position in which the closure covers the opening and a second position in which the opening is uncovered;
wherein the first longitudinal central axis passes through an opening of the second tube portion and the second longitudinal central axis passes through an opening of the first tube portion.
Another aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient proximal end configured to connect to the patient interface and having a patient-distal end, the first tube portion having a first longitudinal central axis that is substantially straight between the patient-proximal end and the patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, the second tube portion having a second longitudinal central axis that is substantially straight between the patient-proximal end and the patient end, wherein at least a portion of the patient-proximal end of the second tube portion is positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion, the vent comprising a vent structure comprising:
a plurality of deflectors configured to deflect the air flow through each vent slot towards a part of the vent housing and/or another component in the respiratory system; and
wherein the connection member further comprises an AAV comprising an opening to the ambient air and a closure configured to move between a first position in which the closure covers the opening and a second position in which the opening is uncovered;
wherein the first longitudinal central axis passes through an opening of the second tube portion and the second longitudinal central axis passes through an opening of the first tube portion.
Another aspect of one form of the present technology is a connection member configured to connect an air circuit to a patient interface to convey a flow of pressurised breathable gas from the air circuit to the patient interface for breathing by a patient, the connection member comprising:
a first tube portion having a patient proximal end configured to connect to the patient interface and having a patient-distal end, the first tube portion having a first longitudinal central axis that is substantially straight between the patient-proximal end and the patient-distal end;
a second tube portion having a patient-proximal end and a patient-distal end configured to connect to the air circuit, the second tube portion having a second longitudinal central axis that is substantially straight between the patient-proximal end and the patient end, wherein at least a portion of the patient-proximal end of the second tube portion is positioned inside at least a portion of the patient-distal end of the first tube portion, the flow of breathable gas being conveyed from the air circuit to the patient interface through the first tube portion and the second tube portion;
a vent for venting gas exhaled by the patient to the ambient air, the vent formed between the first tube portion and the second tube portion, the vent comprising a vent structure comprising:
a projecting portion structured and arranged to inhibit generation of flow layer instabilities, the projecting portion extending outwardly from the vent outlet; and
wherein the connection member further comprises an AAV comprising an opening to the ambient air and a closure configured to move between a first position in which the closure covers the opening and a second position in which the opening is uncovered;
wherein the first longitudinal central axis passes through an opening of the second tube portion and the second longitudinal central axis passes through an opening of the first tube portion.
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.
An aspect of one form of the present technology is a method of manufacturing apparatus.
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.
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.
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.
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.
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.
Other features of the technology will be apparent from consideration of the information contained in the following detailed description, abstract, drawings and claims.
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:
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.
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.
In one form, the present technology comprises a method for treating a respiratory disorder comprising applying positive pressure to the entrance of the airways of a patient 1000.
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.
In certain examples of the present technology, mouth breathing is limited, restricted or prevented.
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.
A non-invasive patient interface 3000 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.
An unsealed patient interface 3800, in the form of a nasal cannula, includes nasal prongs 3810a, 3810b which can deliver air to respective nares of the patient 1000 via respective orifices in their tips. Such nasal prongs do not generally form a seal with the inner or outer skin surface of the nares. The air to the nasal prongs may be delivered by one or more air supply lumens 3820a, 3820b that are coupled with the nasal cannula 3800. The lumens 3820a, 3820b lead from the nasal cannula 3800 to a respiratory therapy device via an air circuit. The unsealed patient interface 3800 is particularly suitable for delivery of flow therapies, in which the RPT device generates the flow of air at controlled flow rates rather than controlled pressures. The “vent” at the unsealed patient interface 3800, through which excess airflow escapes to ambient, is the passage between the end of the prongs 3810a and 3810b of the cannula 3800 via the patient's nares to atmosphere.
If a patient interface is unable to comfortably deliver a minimum level of positive pressure to the airways, the patient interface may be unsuitable for respiratory pressure therapy.
The patient interface 3000 in accordance with one form of the present technology is constructed and arranged to be able to provide a supply of air at a positive pressure of at least 6 cmH2O with respect to ambient.
The patient interface 3000 in accordance with one form of the present technology is constructed and arranged to be able to provide a supply of air at a positive pressure of at least 10 cmH2O with respect to ambient.
The patient interface 3000 in accordance with one form of the present technology is constructed and arranged to be able to provide a supply of air at a positive pressure of at least 20 cmH2O with respect to ambient.
In one form of the present technology, a seal-forming structure 3100 provides a target seal-forming region, and may additionally provide a cushioning function. The target seal-forming region is a region on the seal-forming structure 3100 where sealing may occur. The region where sealing actually occurs—the actual sealing surface—may change within a given treatment session, from day to day, and from patient to patient, depending on a range of factors including for example, where the patient interface was placed on the face, tension in the positioning and stabilising structure and the shape of a patient's face.
In one form the target seal-forming region is located on an outside surface of the seal-forming structure 3100.
In certain forms of the present technology, the seal-forming structure 3100 is constructed from a biocompatible material, e.g. silicone rubber.
A seal-forming structure 3100 in accordance with the present technology may be constructed from a soft, flexible, resilient material such as silicone.
In certain forms of the present technology, a system is provided comprising more than one a seal-forming structure 3100, each being configured to correspond to a different size and/or shape range. For example, the system may comprise one form of a seal-forming structure 3100 suitable for a large sized head, but not a small sized head and another suitable for a small sized head, but not a large sized head.
In one form, the seal-forming structure includes a sealing flange utilizing a pressure assisted sealing mechanism. In use, the sealing flange can readily respond to a system positive pressure in the interior of the plenum chamber 3200 acting on its underside to urge it into tight sealing engagement with the face. The pressure assisted mechanism may act in conjunction with elastic tension in the positioning and stabilising structure.
In one form, the seal-forming structure 3100 comprises a sealing flange and a support flange. The sealing flange comprises a relatively thin member with a thickness of less than about 1 mm, for example about 0.25 mm to about 0.45 mm, which extends around the perimeter of the plenum chamber 3200. Support flange may be relatively thicker than the sealing flange. The support flange is disposed between the sealing flange and the marginal edge of the plenum chamber 3200 and extends at least part of the way around the perimeter. The support flange is or includes a spring-like element and functions to support the sealing flange from buckling in use.
In one form, the seal-forming structure may comprise a compression sealing portion or a gasket sealing portion. In use the compression sealing portion, or the gasket sealing portion is constructed and arranged to be in compression, e.g. as a result of elastic tension in the positioning and stabilising structure.
In one form, the seal-forming structure comprises a tension portion. In use, the tension portion is held in tension, e.g. by adjacent regions of the sealing flange.
In one form, the seal-forming structure comprises a region having a tacky or adhesive surface.
In certain forms of the present technology, a seal-forming structure may comprise one or more of a pressure-assisted sealing flange, a compression sealing portion, a gasket sealing portion, a tension portion, and a portion having a tacky or adhesive surface.
In one form, the non-invasive patient interface 3000 comprises a seal-forming structure that forms a seal in use on a nose bridge region or on a nose-ridge region of the patient's face.
In one form, the seal-forming structure includes a saddle-shaped region constructed to form a seal in use on a nose bridge region or on a nose-ridge region of the patient's face.
In one form, the non-invasive patient interface 3000 comprises a seal-forming structure that forms a seal in use on an upper lip region (that is, the lip superior) of the patient's face.
In one form, the seal-forming structure includes a saddle-shaped region constructed to form a seal in use on an upper lip region of the patient's face.
In one form the non-invasive patient interface 3000 comprises a seal-forming structure that forms a seal in use on a chin-region of the patient's face.
In one form, the seal-forming structure includes a saddle-shaped region constructed to form a seal in use on a chin-region of the patient's face.
In one form, the seal-forming structure that forms a seal in use on a forehead region of the patient's face. In such a form, the plenum chamber may cover the eyes in use.
In one form the seal-forming structure of the non-invasive patient interface 3000 comprises a pair of nasal puffs, or nasal pillows, each nasal puff or nasal pillow being constructed and arranged to form a seal with a respective naris of the nose of a patient.
Nasal pillows in accordance with an aspect of the present technology include: a frusto-cone, at least a portion of which forms a seal on an underside of the patient's nose, a stalk, a flexible region on the underside of the frusto-cone and connecting the frusto-cone to the stalk. In addition, the structure to which the nasal pillow of the present technology is connected includes a flexible region adjacent the base of the stalk. The flexible regions can act in concert to facilitate a universal joint structure that is accommodating of relative movement both displacement and angular of the frusto-cone and the structure to which the nasal pillow is connected. For example, the frusto-cone may be axially displaced towards the structure to which the stalk is connected.
In one form of the technology the patient interface 3000 may be an oro-nasal mask. The patient interface 3000 of an oro-nasal mask comprises a seal-forming structure 3100 having an oral portion 3260 configured to form a seal around the patient's mouth and a nasal portion configured to form a seal around the patient's nasal openings. The oral portion 3260 and the nasal portion may be attached, for example they may be integrally formed.
In one form of the technology the patient interface 3000 may be a type of oro-nasal mask that may be referred to as an “ultra-compact full face mask” (UCFFM). A UCFFM mask is disclosed in Australian Provisional Patent Application No. 2019903948, the contents of which are hereby incorporated by reference.
In certain forms of the present technology, a seal-forming structure 3100 of an UCFFM comprises a nasal portion configured to form a seal to inferior surfaces of the patient's nose. The nasal portion may seal to an inferior periphery of the patient's nose (e.g., surrounding the patient's nares and to the patient's lip superior). In examples, the nasal portion of the seal-forming structure 3100 may be configured to contact the patient's face below the bridge of the nose or below the pronasale.
The nasal portion of the seal-forming structure 3100 may also comprise a medial portion configured to form a seal with an inferior surface of the patient's nose between the patient's nares, for example the columella. The medial portion may be configured so that it is substantially superior-facing in use.
In some examples a majority of the seal formed by the seal-forming surface 3100 to the inferior periphery of the patient's nose may be made by the superior-facing medial portion and lip superior portion. The superior-facing medial portion superior and anterior to the nasal holes of the seal-forming structure may seal against the inferior and partially anterior surfaces of the patient's pronasale. A lip superior portion of the seal-forming structure 3100 may seal against the lip superior. The lip superior portion is provided medially and inferior and posterior to the nasal holes.
In one form of an UCFFM the patient interface 3000 comprises a seal-forming structure 3100 that forms a seal in use around the patient's mouth at an oral portion 3260. The oral portion 3260 comprises a lip inferior portion which forms a seal against the chin region of the patient in use. The lip inferior portion of the seal-forming structure may seal against the lip inferior and supramenton of the patient. Additionally, the oral portion 3260 may comprise an oral hole peripheral portion which contacts the patient's cheeks. The lip inferior portion may be connected to (e.g., contiguous with) the lip superior portion via the oral hole peripheral portion.
The plenum chamber 3200 has a perimeter that is shaped to be complementary to the surface contour of the face of an average person in the region where a seal will form in use. In use, a marginal edge of the plenum chamber 3200 is positioned in close proximity to an adjacent surface of the face. Actual contact with the face is provided by the seal-forming structure 3100. The seal-forming structure 3100 may extend in use about the entire perimeter of the plenum chamber 3200. In some forms, the plenum chamber 3200 and the seal-forming structure 3100 are formed from a single homogeneous piece of material.
In certain forms of the present technology, the plenum chamber 3200 does not cover the eyes of the patient in use. In other words, the eyes are outside the pressurised volume defined by the plenum chamber. Such forms tend to be less obtrusive and/or more comfortable for the wearer, which can improve compliance with therapy.
In certain forms of the present technology, the plenum chamber 3200 is constructed from a transparent material, e.g. a transparent polycarbonate. The use of a transparent material can reduce the obtrusiveness of the patient interface and help improve compliance with therapy. The use of a transparent material can aid a clinician to observe how the patient interface is located and functioning.
In certain forms of the present technology, the plenum chamber 3200 is constructed from a translucent material. The use of a translucent material can reduce the obtrusiveness of the patient interface and help improve compliance with therapy.
In certain forms of the present technology, the plenum chamber 3200 is constructed at least in part from a flexible material, e.g. silicone. In certain forms, the entire plenum chamber 3200 is formed from a flexible material. In certain forms a part of the plenum chamber 3200 comprising a connection port 3600 (allowing for connection to the air circuit 4170) is constructed from a flexible material. For example, an anterior portion of the plenum chamber 3200 may be constructed from a flexible material.
The seal-forming structure 3100 of the patient interface 3000 of the present technology may be held in sealing position in use by the positioning and stabilising structure 3300.
In one form the positioning and stabilising structure 3300 provides a retention force at least sufficient to overcome the effect of the positive pressure in the plenum chamber 3200 to lift off the face.
In one form the positioning and stabilising structure 3300 provides a retention force to overcome the effect of the gravitational force on the patient interface 3000.
In one form the positioning and stabilising structure 3300 provides a retention force as a safety margin to overcome the potential effect of disrupting forces on the patient interface 3000, such as from tube drag, or accidental interference with the patient interface.
In one form of the present technology, a positioning and stabilising structure 3300 is provided that is configured in a manner consistent with being worn by a patient while sleeping. In one example the positioning and stabilising structure 3300 has a low profile, or cross-sectional thickness, to reduce the perceived or actual bulk of the apparatus. In one example, the positioning and stabilising structure 3300 comprises at least one strap having a rectangular cross-section. In one example the positioning and stabilising structure 3300 comprises at least one flat strap.
In one form of the present technology, a positioning and stabilising structure 3300 is provided that is configured so as not to be too large and bulky to prevent the patient from lying in a supine sleeping position with a back region of the patient's head on a pillow.
In one form of the present technology, a positioning and stabilising structure 3300 is provided that is configured so as not to be too large and bulky to prevent the patient from lying in a side sleeping position with a side region of the patient's head on a pillow.
In one form of the present technology, a positioning and stabilising structure 3300 is provided with a decoupling portion located between an anterior portion of the positioning and stabilising structure 3300, and a posterior portion of the positioning and stabilising structure 3300. The decoupling portion does not resist compression and may be, e.g. a flexible or floppy strap. The decoupling portion is constructed and arranged so that when the patient lies with their head on a pillow, the presence of the decoupling portion prevents a force on the posterior portion from being transmitted along the positioning and stabilising structure 3300 and disrupting the seal.
In one form of the present technology, a positioning and stabilising structure 3300 comprises a strap constructed from a laminate of a fabric patient-contacting layer, a foam inner layer and a fabric outer layer. In one form, the foam is porous to allow moisture, (e.g., sweat), to pass through the strap. In one form, the fabric outer layer comprises loop material to engage with a hook material portion.
In certain forms of the present technology, a positioning and stabilising structure 3300 comprises a strap that is extensible, e.g. resiliently extensible. For example, the strap may be configured in use to be in tension, and to direct a force to draw a seal-forming structure into sealing contact with a portion of a patient's face. In an example the strap may be configured as a tie.
In one form of the present technology, the positioning and stabilising structure comprises a first tie, the first tie being constructed and arranged so that in use at least a portion of an inferior edge thereof passes superior to an otobasion superior of the patient's head and overlays a portion of a parietal bone without overlaying the occipital bone.
In one form of the present technology suitable for a nasal-only mask or for a full-face mask, the positioning and stabilising structure includes a second tie, the second tie being constructed and arranged so that in use at least a portion of a superior edge thereof passes inferior to an otobasion inferior of the patient's head and overlays or lies inferior to the occipital bone of the patient's head.
In one form of the present technology suitable for a nasal-only mask or for a full-face mask, the positioning and stabilising structure includes a third tie that is constructed and arranged to interconnect the first tie and the second tie to reduce a tendency of the first tie and the second tie to move apart from one another.
In certain forms of the present technology, a positioning and stabilising structure 3300 comprises a strap that is bendable and e.g. non-rigid. An advantage of this aspect is that the strap is more comfortable for a patient to lie upon while the patient is sleeping.
In certain forms of the present technology, a positioning and stabilising structure 3300 comprises a strap constructed to be breathable to allow moisture vapour to be transmitted through the strap,
In certain forms of the present technology, a system is provided comprising more than one positioning and stabilizing structure 3300, each being configured to provide a retaining force to correspond to a different size and/or shape range. For example, the system may comprise one form of positioning and stabilizing structure 3300 suitable for a large sized head, but not a small sized head, and another. suitable for a small sized head, but not a large sized head.
In one form, the patient interface 3000 includes a vent 3400 constructed and arranged to allow for the washout of exhaled gases, e.g. carbon dioxide.
In certain forms the vent 3400 is configured to allow a continuous vent flow from an interior of the plenum chamber 3200 to ambient whilst the pressure within the plenum chamber is positive with respect to ambient. The vent 3400 is configured such that the vent flow rate has a magnitude sufficient to reduce rebreathing of exhaled CO2 by the patient while maintaining the therapeutic pressure in the plenum chamber in use.
One form of vent 3400 in accordance with the present technology comprises a plurality of holes, for example, about 20 to about 80 holes, or about 40 to about 60 holes, or about 45 to about 55 holes.
The vent 3400 may be located in the plenum chamber 3200. Alternatively, the vent 3400 is located in a decoupling structure, e.g., a swivel.
In one form the vent 3400 is located in a connection member 6000 as described in section 4.6 and shown in
Connection port 3600 allows for connection to the air circuit 4170.
In one form, the patient interface 3000 includes a forehead support 3700.
In certain forms of the technology, the patient interface assembly comprises an anti-asphyxia valve (AAV) 6200.
As explained in section 4.10.4, an anti-asphyxia valve (AAV) 6200 provides a mechanism to enable the patient 1000 to breathe in situations where the blower 4142 stops providing a flow of pressurised air. In certain forms, the AAV 6200 comprises an opening which forms an airflow path between the patient 1000 and the ambient air to provide the patient 1000 with a supply of fresh air. This reduces the risk of excessive CO2 rebreathing by a patient.
In one form, the patient interface 3000 includes an anti-asphyxia valve. Alternatively, in one form the AAV 6200 is located in a connection member 6000 as described in section 4.6 herein.
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 supplementary oxygen. In one form, this allows for the direct measurement of a property of gases within the plenum chamber 3200, such as the pressure.
In some forms of the technology, a patient interface 3000 together with a connection member 6000 form a patient interface assembly.
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 to generate a flow of air for delivery to a patient's airways, such as to treat one or more of the respiratory conditions described elsewhere in the present document.
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 6 cmH2O, or at least 10cmH2O, or at least 20 cmH2O.
As mentioned above, in some forms of the present technology, the central controller 4230 may be configured to implement one or more algorithms 4300 expressed as computer programs stored in a non-transitory computer readable storage medium, such as memory 4260. The algorithms 4300 are generally grouped into groups referred to as modules.
In other forms of the present technology, some portion or all of the algorithms 4300 may be implemented by a controller of an external device such as the local external device 4288 or the remote external device 4286. In such forms, data representing the input signals and/or intermediate algorithm outputs necessary for the portion of the algorithms 4300 to be executed at the external device may be communicated to the external device via the local external communication network 4284 or the remote external communication network 4282. In such forms, the portion of the algorithms 4300 to be executed at the external device may be expressed as computer programs stored in a non-transitory computer readable storage medium accessible to the controller of the external device. Such programs configure the controller of the external device to execute the portion of the algorithms 4300.
In such forms, the therapy parameters generated by the external device via the therapy engine module 4320 (if such forms part of the portion of the algorithms 4300 executed by the external device) may be communicated to the central controller 4230 to be passed to the therapy control module 4330.
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.
In particular, the air circuit 4170 may be in fluid connection with the outlet of the pneumatic block 4020 and/or 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.
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 central controller 4230. One example of an air circuit 4170 comprising a heated wire circuit is described in U.S. Pat. No. 8,733,349, which is incorporated here within in its entirety by reference.
In some forms of the technology, an air circuit 4170 together with a connection member 6000, as described in section 4.6, may form an air circuit assembly that is configured to fluidly connect RPT device 4000 to patient interface 3000.
In some forms of the technology the patient interface assembly comprises a connection member 6000 configured to connect an air circuit 4170 to a patient interface 3000 to convey a flow of pressurised breathable gas from the air circuit 4170 to the patient interface 3000 for breathing by a patient 1000.
To create a compact design for the patient interface assembly the connection member 6000 comprises both a vent structure 6100 and an anti-asphyxia valve (AAV) 6200. A further advantage of the connection member 6000 comprising a vent structure 6100, rather than providing the vent as part of the plenum chamber 3200, is that the patient interface 3000 may have a lower manufacturing cost due to the reduced complexity of this component. This may be especially beneficial as the patient interface 3000, or parts thereof (for example, a cushion formed by the plenum chamber 3200 and seal-forming structure 3100), is typically a frequently replaced product.
In some forms of the technology the connection member 6000 is formed from a substantially rigid material, for instance a polycarbonate.
In one form of the technology, the connection member 6000 comprises a vent structure 6100 to vent a flow of air exhaled from the patient 1000 to the surrounding ambient air. An example of a connection member with a vent structure 6100 is shown in
The connection member 6000 comprises a first tube portion 6110 and a second tube portion 6120. The first tube portion 6110 has a patient-proximal end 6111 and a patient-distal end 6112. In use, the patient-proximal end 6111 is located closer to the patient than the patient-distal end 6112. The second tube portion 6120 has a patient-proximal end 6121 and a patient-distal end 6122. In use, the patient-proximal end 6121 is located closer to the patient than the patient-distal end 6122.
In use, the flow of breathable gas is conveyed from the air circuit 4170 to the patient interface 3000 through the first tube portion 6110 and the second tube portion 6120.
At least a portion of the patient-proximal end 6121 of the second tube portion 6120 is positioned inside at least a portion of the patient-distal end 6112 of the first tube portion 6110.
A vent structure 6100 for venting gas exhaled by the patient 1000 to the ambient air is formed between the first tube portion 6110 and the second tube portion 6120. The vent structure 6100 may be located around the outer periphery of the patient-proximal end 6121 of the second tube portion 6120 in the region where at least a portion of the patient-proximal end 6121 of the second tube portion 6120 is positioned inside at least a portion of the first tube portion 6110.
The vent structure 6100 may comprise a plurality of vent slots 6130 arranged in a region between the first tube portion 6110 and the second tube portion 6120. Some of the air that is exhaled by the patient 1000 flows into the connection member 6000 from the plenum chamber 3200, through the vent slots 6130 and into the surrounding ambient air. The vent slots 6130 may be arranged around the second tube portion 6120. The vent slots may be formed between a plurality of ribs 6140 extending between an outer surface 6125 of the second tube portion 6120 and an inner surface 6115 of the first tube portion 6110. In one form the ribs 6140 are provided on the outer surface 6125 of the second tube portion 6120, for example integrally formed (e.g. moulded) to the outer surface 6125. In another form the ribs 6140 are provided on the inner surface 6115 of the first tube portion 6110, for example integrally formed (e.g. moulded) to the inner surface 6115.
In the form of the technology shown in
In the form of the technology shown in
The connection member 6000 may comprise a tube connector 6150 configured to connect the second tube portion 6120 to the first tube portion 6110. The tube connector 6150 may connect the second tube portion 6120 to the outer surface 6118 of the first tube portion 6110, although in other forms the tube connector 6150 may connect the second tube portion 6120 to another part of the first tube portion 6110. In the embodiment shown in
In alternative forms of the technology the first tube portion 6110 and second tube portion 6120 may be integrally formed, for example co-moulded.
The vent structure 6100 according to forms of the technology described above may provide a number of benefits. For example, the vent structure 6100 may be low cost to manufacture compared to some prior art vent structures. The vent structure 6000 may provide a sufficient level of quietness so as to not disturb the patient 1000 or bed partner 1100. The vent structure 6100 may be configured so that the vent slots 6130 are orientated so that vented gases flow adjacent to the outside of the second tube portion 6120 after exiting the vent structure 6100. This may mean the vented gases are unlikely to be directed towards the patient 1000 or bed partner 1100.
In some forms the Coanda effect may act to assist in ensuring that the air flow of vented gases attaches to the air circuit 4170 downstream of the vent structure 6100, even if the air circuit 4170 is bent. If there is a bend in the air circuit 4170 the air flowing along the outer curve of the bend will continue to follow the air circuit 4170 under the Coanda effect rather than continuing along a straight path in a direction away from the air circuit 4170. This effect may provide a number of advantages. It may help to avoid air flowing towards the patient 1000 or bed partner 1100 as the flow of air exiting the vent structure 6100 tends to stay attached to the outer surface of the air circuit 4170. The attachment of the flow to the outer surface of the air circuit 4170 where it is subject to friction from the air circuit 4170 may also help to further slow the flow of air, reducing noise.
4.6.1.1.1 Vent with Noise Reducing Features
In alternative forms of the technology, the vent structure 6100 may comprise one or more features to reduce the noise caused by the flow of air through the vent and/or reduce the force of the air flow exiting the vent which may disturb, or be uncomfortable for, the patient 1000 and/or bed partner 1100. Examples of such vent features are disclosed in PCT Patent Application No. PCT/AU2020/051211, published as PCT Publication No. WO2021/087570 on 14 May 2021, which is incorporated herein in its entirety by reference. The relevant sections of PCT Publication No. WO2021/087570 have been reproduced below.
It should be appreciated that the concepts and/or features of the vents described in the proceeding sections and illustrated by way of example in
In other forms of the technology, the inner surface 6115 of the first tube portion 6110 of the form of the technology shown in
In other forms of the technology, the vent structure 6100 of the form of the technology shown in
As noted above a vent 3400 may be provided to a part of the respiratory system to allow for the washout of exhaled gases, e.g. carbon dioxide. Venting of the exhaled gas may result in noise caused by the flow of air through the vent 3400 which can disturb the patient 1000 and/or the bed partner 1100. Furthermore, the force of the air flow exiting the vent may disrupt, or be uncomfortable for, the patient 1000 and/or bed partner 1100. Air exiting the vent directly into the surrounding ambient air may also result in flow separation, particularly at high velocities. Flow separation causes an increase in turbulence in the flow of air and therefore noise. The faster the flow of air exiting the vent, the louder the noise associated with the vent 3400. Slowing down the flow of air in the vent will therefore reduce the noise associated with the vent 3400.
In certain forms of the present technology a vent 3400 may be provided in the form of a vent structure 7000 provided to a part of the respiratory system and configured to reduce the noise produced by venting gases and/or to reduce the speed of the air flow as it exits the vent. In some forms, the vent structure 7000 may be formed from a plastics material, for example polycarbonate. In some forms the vent structure 7000 is formed from an assembly of different materials.
In certain forms, the vent structure 7000 may have the advantage of not requiring any diffuser material as is present in prior art vents to reduce jetting of the air flow. Diffuser material is an additional component to a patient interface so adds complexity in manufacture, assembly and use, and may need to be cleaned and/or replaced regularly.
In certain forms of the present technology the vent structure 7000 may be formed as part of a connection member 8000.
In some forms of the technology the connection member 8000 may be a separate or separable component to the circuit 4170 and/or the patient interface 3000. In other forms of the technology the air circuit 4170 or the patient interface 3000 comprises the connection member 8000.
In one form the connection member 8000 may comprise a tube portion 8100 configured to fluidly connect the air circuit 4170 to the patient interface 3000. The tube portion 8100 is typically a circular hollow cylinder or assembly of components forming a generally cylindrical shape with an air path through it to convey air from the air circuit 4170 to the patient interface 3000. In other forms of the technology the tube portion may have a different cross-sectional shape, for example oval, D-shaped or polygonal.
The connection member 8000 may further comprise a vent structure 7000 comprising a vent housing 7100 and a plurality of partitions 7200 inside the vent housing 7100. The plurality of partitions 7200 form therebetween a plurality of vent slots 6300 through which exhaled air can flow. The vent slots 7300 may be partly defined by the vent housing 7100, for example parts of the vent housing 7100 may define the upper and lower walls of each vent slot 7300 while the partitions 7200 define the side walls of each vent slot 7300. The vent slots 7300 comprise a vent inlet 7310 configured to receive an air flow, for example air exhaled by the patient 1000. The vent slots 7300 also comprise a vent outlet 7320 configured to allow the air flow to exit into the surrounding ambient air. Exhaled air passing through the vent slots flows in a direction from the vent inlet 7310 to the vent outlet 7320. The parts of the vent housing 7100 forming the vent slots 7300 and the partitions 7200 may be substantially rigid and fixed in position relative to each other such that the shape of the vent slots does not change during use.
The number of vent slots 7300 in the vent structure 7000 may vary between different forms of the technology. Design features that may be varied to alter the number of vent slots 7300 include the size of the vent structure 7000, the number of partitions 7200 and the thickness of the partitions 7200 forming the vent slots 7300.
As mentioned above a vent 3400 according to forms of the technology is constructed and arranged to allow for the washout of exhaled gases, e.g. carbon dioxide from the patient interface 3000. The vent structure 7000 prevents rebreathing of the exhaled gases while maintaining the therapeutic pressure in the plenum chamber in use. The total size of the vent structure 7000 in particular the vent slots 7300 is therefore formed to be sufficient to allow for washout of the exhaled gases and also to maintain the therapeutic pressure in the plenum chamber 3200. In exemplary forms of the technology in which the vent structure 7000 is formed as part of a connection member 8000, the cross-sectional area of each vent inlet 7310 may be between 1.8 mm2 and 2.5 mm2, for example approximately 2.2 mm2. The total cross-sectional area of the vent outlets may be between 45 mm2 and 50 mm2. In the form of the technology shown in
As the air flows along the vent slots 7300 the air contacts the partitions 7200 and the vent housing 7100 and reduces in speed due to friction of the air flow with the partitions 7200 and walls of the vent housing 7100. Changes in the design of the vent structure 7000 may alter the amount of friction experienced by the air flow, and therefore the speed at which air exits the vent structure 7000.
The higher the total surface area of the vent slots 7300 that the air flow comes into contact with, the lower the speed of the air flow because of the greater frictional or drag forces when there is higher surface area. In general, the more vent slots 7300 there are the greater the overall surface area of the vent structure 7000 that contacts the air flow and therefore the greater the reduction in speed of the venting air. Therefore, forms of the technology having a relatively high number of vent slots 7300 may be more effective in reducing the speed of flow, and therefore reducing the amount of noise created by the air flow, than forms of the technology having a relatively low number of vent slots. However, forms of the technology having more vent slots 7300 may be more complex and costly to manufacture.
The longer the vent slots 7300, the greater the total surface area of the vent structure 7000 that contacts the air flow. Therefore, forms of the technology having relatively long vent slots 7300 may be more effective in reducing the speed of flow, and therefore reducing the amount of noise created by the air flow, than forms of the technology having relatively short vent slots. However, in some forms it may be advantageous for the connection member 8000 to have a relatively compact design. Also, since in some forms of the technology the connection member 8000 may be formed from a rigid material, the connection member 8000 therefore adds further rigidity to the overall rigidity of the mask system, and the longer the vent slots 7300, the greater the size of the rigid connection member 8000. Therefore, vent slots 7300 longer than a certain length will result in a connection member 8000 having a length that may make it difficult for the patient to move or position the patient interface 3000 or air circuit 4170. It will be appreciated that the “certain length” that makes the connection member 8000 too long for a patient's comfort or convenient use will depend on a variety of factors, including the patient's personal preference, the type of respiratory system the connection member 8000 is used with, and the context in which it is used. Nevertheless, it is to be understood that there may, in some circumstances, be an advantage in generally keeping the connection member 8000 relatively short. In certain forms of the technology, for example where the diameter of the air circuit 4170 is 19 mm, the connection member 8000 may be approximately 25 mm or less in length, and in some forms of the technology it may have a length of approximately 15 mm. In other forms of the technology, for example where the diameter of the air circuit 4170 is 15 mm, the connection member 8000 may have a length in the range of 10 mm to 20 mm.
In the forms of the technology shown in
In some forms of the technology (not illustrated), the outer tube portion 7110 may be configured to connect to the patient interface 3000 by a ball and socket arrangement or a swivel ring arrangement to allow a wide range of motion between the patient interface 3000 and the connection member 8000. This decoupling arrangement assists in hindering forces applied to the air circuit from being applied to the patient interface and disrupting the seal with the patient's face. In other forms of the technology, the first end portion of the outer tube portion 8110 may be integrally formed as part of the patient interface 3000, for instance integrally formed with the plenum chamber 3200. In other forms of the technology, the outer tube portion 8110 may be removably connected to the patient interface 3000. This connection may be achieved through a clip arrangement, a screw and thread arrangement, or a snap-fit arrangement. Similarly, in some forms of the technology the first end portion of the inner tube portion 8120 may be configured to connect to an end of the air circuit 4170 via a decoupling arrangement including a ball and socket or a swivel ring arrangement. In other forms of the technology the inner tube portion 8120 may be integrally formed with an end of the air circuit 4170. Alternatively, the inner tube portion 8120 may be removably connected by a clip arrangement, a screw and thread arrangement, or a snap-fit arrangement.
In some forms of the technology, as shown in
In certain forms of the technology the vent housing 7100 comprises the outer tube portion 8110 and the inner tube portion 8120 and the partitions 7200 and vent slots 7300 are located between the outer tube portion 8110 and the inner tube portion 8120. For example, in the forms of the technology illustrated in
In some forms of the technology the partitions 7200 are formed on, or connected to, the outer surface 8125 of the inner tube portion 8120. For example, the partitions 7200 may be integrally formed as part of the inner tube portion 8120, for example in a moulding process. In alternative forms of the technology the partitions 7200 are formed on the inner surface 8115 of the outer tube portion 8110. In alternative forms of the technology the partitions may be formed as a separate component that is positioned between the inner tube portion 8120 and the outer tube portion 8110. In certain forms of the technology, the connection member 8000 is integrally formed in one-piece, for example by a moulding process.
When used with a full-face mask, the connection member 8000 may comprise, or be connected to, an AAV. The connection member 8000 may alternatively be used with other types of masks, examples of which are described herein.
The vent structure 7000 may comprise one or more of a number of sound reducing features as described below. These sound reducing features assist in reducing the sound associated with air flowing through and exiting the vent structure 7000.
In some forms of the technology the connection member 8000 further comprises a sealing member 8200 configured to form a seal to reduce any unwanted flow of air through any gaps or spaces (besides through the vent slots 7300) between the partitions 7200 and the vent housing 7100. Flow of air through such gaps or spaces may generate noise which may disturb the patient. The sealing member 8200 may form a seal at or proximate the vent inlet 7310 to hinder the flow of air through these gaps or spaces thereby preventing the generation of any additional noise. In forms of the technology where the partitions 7200 are formed as part of the inner tube portion 8120, the sealing member 8200 seals the space at the vent inlet 7310 between the partitions 7200 and the inner surface 8115 of the outer tube portion 8110. In forms of the technology where the partitions 7200 are formed as part of the outer tube portion 8110, the sealing member 8200 seals the space at the vent inlet 7310 between the partitions 7200 and the outer surface 8125 of the inner tube portion 8120.
The sealing member 8200 as shown in
The sealing member 8200 comprises a plurality of apertures 8210. The number of apertures corresponds to the number of vent slots 7300. The shape and position of the apertures 8210 may correspond to the shape and position of the vent inlets 7310. For example, the apertures 8210 shown in
In the form of the technology shown in
As can be seen in
The sealing member 8200 may be formed from a flexible material, for instance a silicone or rubber. The sealing member 8200 may be friction fit or interference fit between the inner tube portion 8120 and the outer tube portion 8110. In other forms of the technology the sealing member may comprise a snap fit connection between the inner tube portion 8120 and/or the outer tube portion. In other forms of the technology the sealing member may be adhered to or integrally formed with the inner tube portion 8120 and/or the outer tube portion 8110.
In certain forms of the technology the vent structure 7000 comprises partitions 7200 which are formed such that each vent slot 7300 has a cross-sectional area at a first region 7330 of the vent slots 7300 that is smaller than a cross-sectional area at a second region 7340 of the vent slots 7300, the first region 7330 being closer to the vent inlet 7310 than the second region 7340. In some forms of the technology the first region 7330 is proximate the vent inlet 7310 and/or the second region 7340 is proximate the vent outlet 7320. For example, the partitions 7200 may be formed such that the vent inlet 7310 has a smaller cross-sectional area than the vent outlet 7320.
Each of the vent slots 7300 has a longitudinal axis along the length of the respective vent slot 7300, i.e. in the inlet-outlet direction. In
In the forms of the present technology shown in
In some forms of the technology, as shown in
As seen in
In some forms of the present technology, for example as illustrated in
In
In any given application or location of the vent structure 7000 (for example in a connection member 8000 between an air circuit 4170 and patient interface 3000), it may have an overall size that, irrespective of how the configuration of the vent slots 7300 are varied in other forms of the vent structure 7000 in the same application or location, the vent structure has the same or similar overall size. For example, in the case of the vent structure 7000 forming part of a connection member 8000 as shown in
In some forms of the present technology, as can be seen in
In some forms of the technology, as can be seen in
In some forms of the technology, as can be seen in
In some forms of the technology (not illustrated), each of the partitions 7200 may comprise a curved portion extending between the first region 7330 and the second region 7340. The curved portion may comprise a convex portion and a concave portion joined together such that the curve is continuous. The point of inflection, i.e. where the curved portion changes from convex to concave, may be located at substantially midway between the first region 7330 and the second region 7340. The concave portion may be closer to the vent inlet 7310 and the convex portion may be closer to the vent outlet 7320. The gradient of the concave and convex portions may be similar to the negatively curved portion 7230 and the positively curved portion 7240 as described above and shown in
As shown in
In the forms of the technology shown in
As seen in
In some forms of the technology, as seen in
In some forms of the technology, as shown in
The inner surface 8115 of the outer tube portion 8110 may reduce in diameter along the vent slot 7300 in order to form part of a deflector 7400, as described below.
In alternative forms (not illustrated) the increase in height along the vent slot 7300 is achieved by increasing the diameter of the inner surface 8115 of the outer tube portion 8110 between the third region 7335 and fourth region 7345 whilst the inner tube portion 8120 remains unchanged. In alternative forms the increase in height along the vent slot 7300 is achieved by decreasing the diameter of the outer surface 8125 of the outer tube portion 8120 between the third region 7335 and the fourth region 7345 whilst the outer tube portion 8120 remains unchanged. In alternative forms, as described above and shown in
In some forms of the technology, as shown in
In the forms of the technology shown in
The chamber 7370 may be formed as an enlarged region of the vent slot 7300, for example a region having a greater height and/or width than adjacent regions of the vent slot 7300. For example, in the forms of the technology shown in
The chamber 7370 may be a form of acoustic attenuation chamber. The acoustic attenuation chamber reduces the noise of the air flow. In use, acoustic waves created by the air flowing through the vent slot reflect off the walls of the chamber 7370 and can interfere with other acoustic waves. For example, the acoustic chamber 7370 in the exemplary forms of the technology illustrated has an upper wall at an angle of approximately 15° to 20° from the axis of the tube portion A2. Interference of the acoustic waves reflected off this wall with the source of the acoustic waves (for example those generated on the lower wall) may result in the cancellation of some of the acoustic waves at certain wavelengths or frequencies. This will assist in reducing the noise of the air flow in the vent structure 7000.
In the forms of the technology shown in
An increased steepness of the walls of the chamber 7370 (i.e. the angle of the walls of the chamber 7370 relative to central axis A2) results in a more drastic change in the direction of the air flow compared to forms of the technology with shallower such angles. This enhances the acoustic attenuation effects of the chamber and reduces the flow velocity. In some forms of the technology, this may be achieved by providing a relatively steep outer surface 8125 of the inner tube portion 8120 and/or a relatively steep inner surface 8115 or the outer tube portion 8110. The need to balance this consideration against the advantages of a compact design may limit the steepness that the walls of the chamber 7370 are given in practice.
In the form of the technology shown in
In some forms of the technology the inlet 7371 to the chamber 7370 is offset from the outlet 7372 to the chamber 7370. The offset between the inlet 7371 and the outlet 7372 results in a vent slot 7300 that is not straight, i.e. one longitudinal section of the vent slot 7300 has an axis that is offset from the axis of another longitudinal section of the vent slot 7300. This assists in preventing noise generated upstream of the chamber 7370 propagating downstream of the chamber 7370. If the inlet 7371 and the outlet 7372 are offset any acoustic waves travelling through the vent slots 7300 are more likely to encounter at least a portion of a wall of the vent slot 7300 which may result in interference of the acoustic waves as discussed above and therefore a reduction in noise.
In the forms of the technology shown in
In the form of the technology shown in
In
In certain forms of the technology the vent structure 7000 comprises a plurality of deflectors 7400 configured to deflect the flow of air through each vent slot 7300 towards a part of the vent housing 7100 and/or another component in the respiratory system. In the forms of the technology shown in
The deflector 7400 in each vent slot 7300 may be a wall of the vent slot 7300, or a separate component positioned in the path of the air flow through the vent slot 7300, positioned and arranged at an angle to the general direction of the air flow through the vent to cause the air flow to change direction when it contacts the deflector 7400. The deflector 7400 acts as a brake to slow down the flow through friction caused by the flow contacting the deflector 7400.
Each deflector 7400 is positioned and arranged to cause the exiting air flow to flow against a component downstream of the deflector 7400 and, in some forms of the technology, a component downstream of the vent outlet 7320. That downstream component may be another part of the vent structure 7000 or another part of the respiratory system. If the air exiting the vent outlet 7320 is directed towards another component, that component will apply frictional or drag forces to the flow of air, reducing the speed of the flow of air, and therefore the level of noise it creates. Directing the flow of air exiting the vent outlet 7320 towards a component that is, for example part of the vent structure 7000 or respiratory system, will also reduce jets of air being directed towards, and therefore disturbing, the patient 1000 or the bed partner 1100. Additionally, a reduction in the speed of the air flow will also reduce the disruptions to the patient 1000 or bed partner 1100.
The plurality of deflectors 7400 may be provided to, for example formed on or connected to, an inner surface 7110 of the vent housing 7100. In the form of the technology shown in
In the form of the technology shown in
In the form of the technology shown in
In the form of the technology shown in
In the form of the technology shown in
The step down region 8130 may be formed by the outer surface 8125 of the inner tube portion 8120 comprising a radially inward step 8131 having an upstream end 8132 and a downstream end 8133, wherein the upstream end 8132 of the radially inwards step 8131 is at a greater radial distance from the central axis than the downstream end 8133 of the radially inward step 8131. In the forms of the technology shown in
In certain forms of the technology, such as shown in
As noted above, in the form of the technology shown in
The step down region 8130 may form, or contribute to forming, a number of the sound reducing features already described, including any one or more of the expanding height portion 7360, the acoustic attenuation chamber 7370 and the deflector 7400.
In the forms of the technology shown in
In the form of the technology shown in
In other forms of the technology the outer surface of the outer tube portion 8110 may maintain a constant diameter along the length of the connection member 8000.
In other words, any bend or change in orientation of the vent slots 7300 may, in some forms of the technology, also be associated with corresponding bends or changes in direction of the outer and inner surfaces of the respective tube portions forming the vents slots 7300 while, in other forms of the technology, the bends or changes in orientation of the vent slots 7300 are internal features only and the outer surfaces of the respective tube portions have a constant diameter along their length, or have some other shape or configuration that is not sympathetic to the shape of the vent slots 7300. Generally speaking, thicker walls of components such as tube portions results in greater weight. A lighter tube portion 8100 will result in a lighter connection member 8000. A lighter connection member 8000 may be more comfortable for the patient 1000 and may be cheaper to manufacture if it has less material.
In some forms of the technology the deflectors 7400 result in the air flow exiting the vent flowing in adjacent the outer surface of the air circuit 4170 and in a direction that is along (i.e. parallel to) the outer surface of the air circuit 4170. This may either be because the deflectors are located adjacent the air circuit 4170 or because the outer surface of the connection member 8000 or inner tube portion 8120 is aligned with the outer surface of the air circuit 4170. The air circuit 4170 may be formed from a flexible tube that can bend during use. In some forms the Coanda effect may act to assist in ensuring that the air flow attaches to the air circuit even if the tube is bent. If there is a bend in the tube the air flowing along the outer curve of the bend will continue to follow the tube under the Coanda effect rather than continuing along a straight path in a direction away from the tube. This effect provides a number of advantages. It helps to avoid air flowing towards the patient 1000 or bed partner 1100 as the flow of air exiting the vent 3400 tends to stay attached to the outer surface of the air circuit 4170. The attachment of the flow to the outer surface of the air circuit 4170 where it is subject to friction from the air circuit 4170 also helps to further slow down the flow of air, reducing noise.
In one form of the technology shown in
In the example shown in
In the forms of the technology shown in
In the form of the technology shown in
In other forms of the technology, the shape of the projecting portion 7500, including the size and shape of the wave-shaped profile, may be different. In some examples the wave shapes may be shallower or deeper, i.e. the difference between the first length, L1, and the second length, L2, may be greater or less than that shown in
Testing of the form of the technology shown in
The forms of the technology illustrated in
In some examples the axis A1 of the vent slots 7300 may not be parallel to the longitudinal central axis A2 of the connection member 8000. For example, the vent slots 7300 may be oriented on the tube portion 8100 to direct the flow of air exiting the vent outlet 7320 in a certain direction that, during typical use of the connection member 8000, may be likely to be away from the patient 1000 or bed partner 1100.
The preceding sections describe forms of the technology where the vent 3400 in the respiratory system is formed in, or as part of, a connection member 8000 connecting the air circuit 4170 to the patient interface 3000. In other forms of the technology, the vent 3400 may be comprised as part of another part of the respiratory system. When comprised in other parts of the respiratory system, the vent 3400 may include many of the same, or similar features to those described above. While the following paragraphs describe some features of exemplary vents 3400 formed as part of a patient interface 3000 and a positioning and stabilising structure 3300, it will be understood that any one or more of the features of a vent 3400 described above in the context of a connection member 8000 may be part of a vent 3400 forming part of a patient interface 3000 or a positioning and stabilising structure 3300, where suitable.
In some forms of the technology, a patient interface 3000 comprising a plenum chamber 3200 and a seal-forming structure 3100 as described above may further comprise a vent structure 7000. The vent structure 7000 allows a continuous flow of gases exhaled by the patient 1000 from an interior of the plenum chamber to ambient. The vent structure 7000 is sized and shaped to maintain the therapeutic pressure in the plenum chamber 3200 in use. The vent structure 7000 may comprise a vent housing 7100 and a plurality of partitions 7200 forming a plurality of vent slots 7300. In these forms, the vent structure 7000 may be structured and arranged in a form that is specifically adapted to the geometry of the patient interface 3000. The vent structure 7000 may comprise at least one of the noise reduction features, i.e. the increase in cross-sectional area, the deflector, or the projecting portion, as described above.
In some forms of the technology the vent structure 7000 is provided to a portion of the plenum chamber 3200, for example a portion that is on an anterior side of the plenum chamber 3200 when the patient interface 3000 is donned by a patient 1000. The vent structure 7000 may comprise a vent housing 7100 provided to the surface of the plenum chamber 3200 and vent slots 7300 that are arranged side-by-side and adopt a similar geometry to the surface of the plenum chamber 3200 proximate the vent structure 7000. The outer surface of the plenum chamber 3200 may form part of the vent housing 7100. The vent housing 7100 and the vent slots 7300 may be configured to follow the general shape, i.e. curvature, of the plenum chamber 3200. In some forms of the technology the vent structure 7000 may be provided to a central region of the plenum chamber 3200 and in alternative embodiments it may be located in a peripheral region of the plenum chamber 3200.
It has previously been described that the vent structure 7000 may comprise a plurality of deflectors 7400 configured to deflect the flow of air through each vent slot 7300 towards a part of the vent housing 7100 and/or another component in the respiratory system. In forms of the technology where the vent structure 7000 forms part of the patient interface 3000, the downstream component that the air flow is deflected towards may be part of the plenum chamber 3200, part of the air circuit 4170 or part of a component connecting the air circuit 4170 to a connection port 3600 in the patient interface 3000, for example an elbow.
In some forms of the technology, a positioning and stabilising structure 3300 is configured to provide a force to hold a seal-forming structure 3100 in a therapeutically effective position on a patient's head in use. The positioning and stabilising structure 3300 comprises at least one gas delivery tube being constructed and arranged to contact at least a region of the patient's head superior to an otobasion superior of the patient's head. An end of the at least one gas delivery tube is configured to fluidly connect to a plenum chamber 3200. The positioning and stabilising structure 3300 further comprises a connection port to receive a flow of air from an air circuit 4170 and to deliver the flow of air to the entrance of the patient's airways via the seal-forming structure 3100, wherein the connection port is provided to a portion of the gas delivery tube superior to the otobasion superior of the patient's head. The positioning and stabilising structure 3300 further comprises a vent structure 7000 comprising a vent housing 7100 and a plurality of partitions 7200 forming a plurality of vent slots 7300. The vent structure 7000 preferably comprises at least one of the noise reduction features described above, i.e. the increase in cross-sectional area, the deflector, or the projecting portion, adapted into a form that is suitable within the overall arrangement and geometry of a vent structure in a positioning and stabilising structure 3300.
In certain forms, the vent structure 7000 may be comprised as part of a gas delivery tube in a positioning and stabilising structure 3300 and have a similar configuration to the connection member 8000 described above. In such forms, the outer tube portion 8110 and the inner tube portion 8120 may be configured to connect to upstream and downstream portions of the gas delivery tube respectively. In some forms of the technology the vent slots 7300 may be provided to a side of the connection member 8000 that faces away from the patient's face in use and a side of the connection member 8000 facing towards the patient's face in use has no vent slots 7300. In alternative forms of the technology, the vent structure 7000 may be provided to a region of the outer surface of the gas delivery tube.
The vent outlet 7320 may have a corresponding outlet in the positioning and stabilising structure 3300 to allow the flow of air to exit into the surrounding ambient air. In some forms of the technology, the outlet in the positioning and stabilising structure may be a hole or a plurality of holes in the region where the vent outlet 7320 is located. In other forms of the technology, the outlet in the positioning and stabilising structure may be a region with a reduced thickness, for example with only a thin layer of material, where the vent outlet 7320 is located.
In some forms of the technology the vent structure 7000 may be provided to a portion of the gas delivery tube that is positioned over the cheek region of the patient's face in use. This may reduce the amount of deadspace in the system by reducing the distance between the vent structure 7000 and the patient's mouth/nose where the air is exhaled compared to forms of the technology in which the vent structure 7000 is provided to a portion of the gas delivery tube further from the patient's mouth/nose, for example a portion positioned superior to the otobasion superior in use.
It has previously been described that the vent structure 7000 may comprise a plurality of deflectors 7400 configured to deflect the flow of air through each vent slot 7300 towards a part of the vent housing 7100 and/or another component in the respiratory system. In forms of the technology where the vent structure 7000 forms part of a positioning and stabilising structure 3300, as described above, the downstream component that the air flow is deflected towards may be another part of the positioning and stabilising structure 3300, for example a part of the gas delivery tube that is positioned in use superior to the vent structure 7000.
In some forms of the technology in addition to the vent 3400 constructed and arranged to allow for the washout of exhaled gases there may be a further second vent (not illustrated) configured to vent air received from the RPT device 4000 before the air is received by the patient 1000. The second vent may be configured and arranged to reduce the flow rate of air from the RPT device 4000 that is received by the patient 1000 whilst maintaining the pressure of the flow of air to the patient 1000. The second vent may be at a different location in the respiratory therapy system to vent 3400.
In some forms of the technology the second vent may be located along the air circuit 4170. In forms in which both the vent 3400 and the second vent are located along the air circuit 4170, the second vent may be provided to the air circuit 4170 at a different location to vent 3400, for example the second vent may be located on the air circuit 4170 at a distance closer to the RPT device 4000 than vent 3400.
In some forms of the technology the second vent may be in the form of a vent structure 7000 according to any of the forms of technology as described above. In some forms of the technology the vent structure may be in the form of a connection member 8000 as described above. The connection member 8000 may be provided to the air circuit 4170 such that the connection member 8000 is connected at respective ends to upstream and downstream sections of the air circuit 4170. The air circuit 4170 and the connection member 8000 may be connected in a similar manner as described above.
In one form of the technology, the connection member 6000 comprises an anti-asphyxia valve (AAV) 6200 to provide a flow of air to the patient 1000 from the ambient air when the blower 4142 is not working. An example of a connection member 6000 with an AAV 6200 is shown in
The connection member 6000 comprises an AAV 6200 comprising an opening 6210 to the ambient air and a closure 6220 that is configured to move between a first position in which the closure 6220 covers the opening 6210 and a second position in which the opening 6210 is uncovered. The AAV 6200 is configured so that, when a flow of pressurised gas is being supplied to the patient interface 3000 from the air circuit 4170, the closure 6220 is in the first position. For example, the flow of pressurised gas may exert a force on the closure 6220, moving it into the first position. The AAV 6200 is also configured so that, when there is no pressurised flow of gas being supplied to the patient interface 3000, the closure 6220 is in the second position. For example, the flow of gas caused by the patient's breathing may exert a force on the closure 6220, moving it into the second position. In the form of the technology shown in
In the form of the technology shown in
In the form of the technology shown in
In the form of the technology shown in
In the form of the technology shown in
When the closure 6220 is in the second position the flap 6221 substantially covers the patient-proximal end 6121 of the second tube portion 6120 thereby preventing flow of gas between the first tube portion 6110 and the second tube portion 6120 during use. This assists in directing the flow of exhaled air from the patient 1000 through the opening 6210 and provides an air flow path for the patient 1000 to breathe the surrounding ambient air through the opening 6210, preventing the patient rebreathing exhaled CO2. In the form of the technology shown in
In use, when the blower 4142 is supplying a flow of pressurised air, the supply of pressurised air through the second tube portion 6120 pushes the hingedly mounted flap 6221 from the second position into the first position where it covers the opening 6210. When the blower 4142 does not supply a flow of pressurised air, the patient's breathing draws air through opening 6210 from ambient, pushing the hingedly mounted flap 6221 against the patient-proximal end 6121 of the second tube portion 6120. In some forms of the technology, the hingedly mounted flap 6221 may be biased to the second position.
In use, the opening 6210 of the AAV 6200 is positioned on a side of the connection member 6000 facing generally away from the patient, e.g. in an anterior direction. By facing away from the patient 1000, the flow of air through the opening 6210 when in the second position will be less likely to disturb the patient 1000 than if the opening 6210 was on a side of the connection member 6000 facing towards the patient.
The first tube portion 6110 has a patient-proximal end 6111 configured to connect to the patient interface 3000, for example to the connection port 3600. In some forms of the technology, this is a removable connection such that the patient interface 3000 and the connection member 6000 can be disconnected from each other, for instance to assist in cleaning or replacing parts.
In the form of the technology shown in
In the form of the technology shown in
The connection member 6000 may be configured to be relatively short and may be as short as possible to minimise the amount of bulk and stiffness added to the patient interface by the connection member 6000. For example, in some forms, the connection member 6000 may have a length of between 35 mm and 50 mm, for example in some forms the length of the connection member 6000 may be approximately 40 mm. In other forms the connection member 6000 may have a different length.
In some forms of the technology a short, compact connection member 6000 connected to a plenum chamber 3200 that is at least partly formed of a flexible material may mean that the patient interface assembly is configured to decouple forces between the air circuit 4170 and the patient interface 3000 sufficiently without other decoupling mechanisms being used, for example a rotatable elbow connecting the air circuit 4170 to the plenum chamber 3200. The connection member 6000 may be able to rotate to a sufficient extent, for example through angles up to approximately 10° from the normal, due to the flexibility and compliance in the plenum chamber 3200 to adequately decouple most forces likely to be exerted on the air circuit 4170 during use.
The patient-distal end 6122 of the second tube portion 6120 is configured to connect to the air circuit 4170. In some forms of the technology, this may be a removable connection such that the air circuit 4170 and the connection member 6000 can be disconnected. Examples of suitable removable connections include a screw-and-thread connection or a snap-fit connection. In other forms this may be a fixed or permanent connection for instance via an adhesive. In the form of the technology shown in
In some forms of the technology, the connection member 6000 may also include a passive heat-moisture exchanger that may absorb heat and moisture from gas exhaled by the patient. The incoming flow of breathable gas to be supplied to the patient's airways may be heated and humidified by the heat and moisture held in the heat-moisture exchanger. An example of a heat-moisture exchanger is disclosed in Australian Patent Application No. 2014295910 which is incorporated here within in its entirety by reference.
In some forms of the technology, a heat-moisture exchanger may be positioned on a region of the connection member 6000 that is close to the patient 1000 in use, for instance adjacent the patient-proximal end 6111 of the first tube portion 6110. In other forms of the technology, a heat-moisture exchanger may be positioned within the connection member 6000 between the AAV 6200 and the vent structure 6100. This may increase the length of the connection member by approximately the length of the heat-moisture exchanger, which may be approximately at least 20 mm in some forms.
In some forms of the technology, the connection member 6000 is substantially straight. The connection member 6000 may have a substantially straight central longitudinal axis.
In one form of the technology the first tube portion 6110 has a first longitudinal central axis D-D that is substantially straight between the patient-proximal end 6111 and the patient-distal end 6112. The second tube portion 6120 has a second longitudinal central axis C-C that is substantially straight between the patient-proximal end 6121 and the patient-distal end 6122. The first tube portion 6110 and the second tube portion 6120 are arranged with the first longitudinal central axis D-D of the first tube portion 6110 substantially parallel to the second longitudinal central axis C-C of the second tube portion 6120. In some forms of the technology the first longitudinal central axis D-D and the second longitudinal central axis C-C are axially aligned. In such forms, the first tube portion 6110 and the second tube portion 6120 are arranged concentrically with regard their circular cross-sections. Similarly, the third tube portion 6155 may also be arranged concentrically with the first tube portion 6110 and the second tube portion 6120. In other forms, the first tube portion 6110 and the second tube portion 6120 may be arranged with the first longitudinal central axis D-D substantially parallel to, but offset from, the second longitudinal central axis C-C.
The first tube portion 6110 and the second tube portion 6120 may be arranged with their respective longitudinal central axes parallel or close-to-parallel. For example, in some forms of the technology the first tube portion 6110 and the second tube portion 6120 may be arranged so that the first longitudinal central axis D-D, when extended beyond the ends of the first tube portion 6110, passes through the opening 6127 at the patient-distal end 6122 of the second tube portion 6120, and the second longitudinal central axis C-C, when extended beyond the ends of the second tube portion 6110, passes through the opening at the patient-proximal end 6111 of the first tube portion 6110.
Having a substantially straight connection member 6000 may make the patient interface assembly less bulky and obtrusive to the patient 1000 compared to a patient interface assembly that includes an elbow. As the mask is less bulky and obtrusive to the patient 1000 it may also make the mask easier, more comfortable and less claustrophobic for the patient to wear. A substantially straight connection member may also be easier to manufacture and therefore cheaper to produce than an elbow.
In some forms of the technology the AAV 6200 is located in a position on the connection member 6000 closer to the patient interface 3000 than the vent structure 6100 is to the patient interface 3000 when in use. Equivalently, the AAV 6200 is closer to the patient-proximal end 6111 of the first tube portion 6110 than the vent structure 6100 is to the patient-proximal end 6111 of the first tube portion 6110. That is, the AAV 6100 is located upstream, when considering the direction of the flow of air as the patient exhales, of the vent structure 6100.
An advantage of providing the AAV 6200 relatively close to the patient's airways is that this arrangement reduces the amount of exhaled air that is re-breathed by the patient 1000 compared to if the AAV 6200 is further from the patient's airways. In some jurisdictions, the patient interface assembly must pass a re-breath test, which requires that only a certain amount of exhaled air can be re-breathed by the patient 1000. By providing the AAV 6200 relatively close to the patient's airways, for example closer to the patient interface 3000 than the vent structure 6100 in the form of connection member 6000 shown in the figures, the volume between the patient's airways and the AAV 6200 is reduced. This may help patient interface assemblies comprising the connection member 6000 pass such re-breath tests.
The connection member 6000 may be configured for use with a patient interface 3000 having a relatively small plenum chamber 3200. Such a patient interface assembly has a relatively small functional dead space. Functional dead space may be defined as the volume of exhaled air that is trapped within the system and that the patient subsequently re-breathes. It is desirable that functional dead space is kept within a safe range, or in the most extreme cases this could lead to patient suffocation. In circumstances where the functional dead space is small, the vent structure 6100 can be located further from the patient's airways while still venting the necessary amount of exhaled air compared to if the connection member 6000 is used with a patient interface 3000 having a larger plenum chamber 3200. Therefore, the connection member 6000 according to the forms of the technology described herein is suitable for use with a patient interface 3000 having a relatively small plenum chamber 3200 because the vent structure 6100 is located at a position on the connection member 6000 further from the patient interface 3000 than the AAV 6200 in use.
Another advantage of the AAV 6200 being positioned relatively close to the patient interface 3000 (e.g. proximal the patient-proximal end 6111 of the first tube portion 6110) is that a relatively small opening 6210 still enables sufficient exhaled air to vent from the patient interface assembly when the AAV 6200 is open for the patient interface assembly to pass a re-breath test. An opening 6210 of an AAV 6200 generally needs to be larger the further the AAV 6200 is located in use from the patient's airways to be able to vent a sufficient amount of exhaled air. The smaller the opening 6210, the smaller the connection member 6000 may be made overall. Additionally, having a smaller opening 6210 makes the AAV 6200 less visually obtrusive to the overall design of the connection member 6000 and the patient interface assembly as a whole. In certain forms of the technology the area of the opening 6210 of the AAV 6200 may be between 70 mm2 and 90 mm2 and in some forms may be approximately 80 mm2. In other forms the opening 6210 may have a different area.
A further advantage of locating the AAV 6200 closer to the patient in use than the vent structure 6100 is that the flow of air exiting the vent structure 6100 may be able to remain attached to the air circuit 4170 (through the Coanda effect as described earlier) without any interruption to the flow of air that may be caused by passing any components forming the AAV 6200. Any disruption to the flow of air may deflect the flow of air towards the patient 1000 or bed partner 1100 causing discomfort. The flow of air remaining attached to the air circuit 4170 also reduces the speed and turbulence of the flow of air, which reduces the noise of the vent in use.
In one form of the present technology there is provided a humidifier 5000 (e.g. as shown in
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
Various respiratory therapy modes may be implemented by the disclosed respiratory therapy system.
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.
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. atmospheric air enriched with oxygen.
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.
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.
In another example, ambient pressure may be the pressure immediately surrounding or external to the body.
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.
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.
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.
Flow rate: The volume (or mass) of air delivered per unit time. Flow rate may refer to an instantaneous quantity. In some cases, a reference to flow rate will be a reference to a scalar quantity, namely a quantity having magnitude only. In other cases, a reference to flow rate will be a reference to a vector quantity, namely a quantity having both magnitude and direction. Flow rate may be given the symbol Q. ‘Flow rate’ is sometimes shortened to simply ‘flow’ or ‘airflow’.
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.
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.
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.
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.
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.
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.
Patient: A person, whether or not they are suffering from a respiratory condition.
Pressure: Force per unit area. Pressure may be expressed in a range of units, including cmH2O, g-f/cm2 and hectopascal. 1 cmH2O is equal to 1 g-f/cm2 and is approximately 0.98 hectopascal (1 hectopascal=100 Pa=100 N/m2=1 millibar 0.001 atm). In this specification, unless otherwise stated, pressure is given in units of cmH2O.
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.
Respiratory Pressure Therapy (RPT): 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.
Ventilator: A mechanical device that provides pressure support to a patient to perform some or all of the work of breathing.
Silicone or Silicone Elastomer: A synthetic rubber. In this specification, a reference to silicone is a reference to liquid silicone rubber (LSR) or a compression moulded silicone rubber (CMSR). One form of commercially available LSR is SILASTIC (included in the range of products sold under this trademark), manufactured by Dow Corning. Another manufacturer of LSR is Wacker. Unless otherwise specified to the contrary, an exemplary form of LSR has a Shore A (or Type A) indentation hardness in the range of about 35 to about 45 as measured using ASTM D2240.
Polycarbonate: a thermoplastic polymer of Bisphenol-A Carbonate.
Resilience: Ability of a material to absorb energy when deformed elastically and to release the energy upon unloading.
Resilient: Will release substantially all of the energy when unloaded. Includes e.g. certain silicones, and thermoplastic elastomers.
Hardness: The ability of a material per se to resist deformation (e.g. described by a Young's Modulus, or an indentation hardness scale measured on a standardised sample size).
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.
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.
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 cmH2O pressure.
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.
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.
Breathing rate: The rate of spontaneous respiration of a patient, usually measured in breaths per minute.
Duty cycle: The ratio of inhalation time, Ti to total breath time, Ttot.
Effort (breathing): The work done by a spontaneously breathing person attempting to breathe.
Expiratory portion of a breathing cycle: The period from the start of expiratory flow to the start of inspiratory flow.
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.
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:
Hyperpnea: An increase in flow to a level higher than normal.
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.
Ala: the external outer wall or “wing” of each nostril (plural: alar)
Alar angle:
Alare: The most lateral point on the nasal ala.
Alar curvature (or alar crest) point: The most posterior point in the curved base line of each ala, found in the crease formed by the union of the ala with the cheek.
Auricle: The whole external visible part of the ear.
(nose) Bony framework: The bony framework of the nose comprises the nasal bones, the frontal process of the maxillae and the nasal part of the frontal bone.
(nose) Cartilaginous framework: The cartilaginous framework of the nose comprises the septal, lateral, major and minor cartilages.
Columella: the strip of skin that separates the nares and which runs from the pronasale to the upper lip.
Columella angle: The angle between the line drawn through the midpoint of the nostril aperture and a line drawn perpendicular to the Frankfort horizontal while intersecting subnasale.
Frankfort horizontal plane: A line extending from the most inferior point of the orbital margin to the left tragion. The tragion is the deepest point in the notch superior to the tragus of the auricle.
Glabella: Located on the soft tissue, the most prominent point in the midsagittal plane of the forehead.
Lateral nasal cartilage: A generally triangular plate of cartilage. Its superior margin is attached to the nasal bone and frontal process of the maxilla, and its inferior margin is connected to the greater alar cartilage.
Lip, lower (labrale inferius):
Lip, upper (labrale superius):
Greater alar cartilage: A plate of cartilage lying below the lateral nasal cartilage. It is curved around the anterior part of the naris. Its posterior end is connected to the frontal process of the maxilla by a tough fibrous membrane containing three or four minor cartilages of the ala.
Nares (Nostrils): Approximately ellipsoidal apertures forming the entrance to the nasal cavity. The singular form of nares is naris (nostril). The nares are separated by the nasal septum.
Naso-labial sulcus or Naso-labial fold: The skin fold or groove that runs from each side of the nose to the corners of the mouth, separating the cheeks from the upper lip.
Naso-labial angle: The angle between the columella and the upper lip, while intersecting subnasale.
Otobasion inferior: The lowest point of attachment of the auricle to the skin of the face.
Otobasion superior: The highest point of attachment of the auricle to the skin of the face.
Pronasale: the most protruded point or tip of the nose, which can be identified in lateral view of the rest of the portion of the head.
Philtrum: the midline groove that runs from lower border of the nasal septum to the top of the lip in the upper lip region.
Pogonion: Located on the soft tissue, the most anterior midpoint of the chin.
Ridge (nasal): The nasal ridge is the midline prominence of the nose, extending from the Sellion to the Pronasale.
Sagittal plane: A vertical plane that passes from anterior (front) to posterior (rear). The midsagittal plane is a sagittal plane that divides the body into right and left halves.
Sellion: Located on the soft tissue, the most concave point overlying the area of the frontonasal suture.
Septal cartilage (nasal): The nasal septal cartilage forms part of the septum and divides the front part of the nasal cavity.
Subalare: The point at the lower margin of the alar base, where the alar base joins with the skin of the superior (upper) lip.
Subnasal point: Located on the soft tissue, the point at which the columella merges with the upper lip in the midsagittal plane.
Supramenton: The point of greatest concavity in the midline of the lower lip between labrale inferius and soft tissue pogonion
Frontal bone: The frontal bone includes a large vertical portion, the squama frontalis, corresponding to the region known as the forehead.
Mandible: The mandible forms the lower jaw. The mental protuberance is the bony protuberance of the jaw that forms the chin.
Maxilla: The maxilla forms the upper jaw and is located above the mandible and below the orbits. The frontal process of the maxilla projects upwards by the side of the nose, and forms part of its lateral boundary.
Nasal bones: The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face, and form, by their junction, the “bridge” of the nose.
Nasion: The intersection of the frontal bone and the two nasal bones, a depressed area directly between the eyes and superior to the bridge of the nose.
Occipital bone: The occipital bone is situated at the back and lower part of the cranium. It includes an oval aperture, the foramen magnum, through which the cranial cavity communicates with the vertebral canal. The curved plate behind the foramen magnum is the squama occipitalis.
Orbit: The bony cavity in the skull to contain the eyeball.
Parietal bones: The parietal bones are the bones that, when joined together, form the roof and sides of the cranium.
Temporal bones: The temporal bones are situated on the bases and sides of the skull and support that part of the face known as the temple.
Zygomatic bones: The face includes two zygomatic bones, located in the upper and lateral parts of the face and forming the prominence of the cheek.
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.
Larynx: The larynx, or voice box houses the vocal folds and connects the inferior part of the pharynx (hypopharynx) with the trachea.
Lungs: The organs of respiration in humans. The conducting zone of the lungs contains the trachea, the bronchi, the bronchioles, and the terminal bronchioles. The respiratory zone contains the respiratory bronchioles, the alveolar ducts, and the alveoli.
Nasal cavity: The nasal cavity (or nasal fossa) is a large air filled space above and behind the nose in the middle of the face. The nasal cavity is divided in two by a vertical fin called the nasal septum. On the sides of the nasal cavity are three horizontal outgrowths called nasal conchae (singular “concha”) or turbinates. To the front of the nasal cavity is the nose, while the back blends, via the choanae, into the nasopharynx.
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).
Anti-asphyxia valve (AAV): The component or sub-assembly of a mask system that, by opening to atmosphere in a failsafe manner, reduces the risk of excessive CO2 rebreathing by a patient.
Elbow: An elbow is an example of a structure that directs an axis of flow of air travelling therethrough to change direction through an angle. In one form, the angle may be approximately 90 degrees. In another form, the angle may be more, or less than 90 degrees. The elbow may have an approximately circular cross-section. In another form the elbow may have an oval or a rectangular cross-section. In certain forms an elbow may be rotatable with respect to a mating component, e.g. about 360 degrees. In certain forms an elbow may be removable from a mating component, e.g. via a snap connection. In certain forms, an elbow may be assembled to a mating component via a one-time snap during manufacture, but not removable by a patient.
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.
Headgear: Headgear will be taken to mean a form of positioning and stabilizing structure designed for use on a head. For example, the headgear may comprise 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 respiratory therapy. Some ties are formed of a soft, flexible, elastic material such as a laminated composite of foam and fabric.
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.
Plenum chamber: a mask plenum chamber will be taken to mean a portion of a patient interface having walls at least partially enclosing a volume of space, the volume having air therein pressurised above atmospheric pressure in use. A shell may form part of the walls of a mask plenum chamber.
Seal: May be a noun form (“a seal”) which refers to a structure, or a verb form (“to seal”) which refers to the effect. Two elements may be constructed and/or arranged to ‘seal’ or to effect ‘sealing’ therebetween without requiring a separate ‘seal’ element per se.
Shell: A shell will be taken to mean a curved, relatively thin structure having bending, tensile and compressive stiffness. For example, a curved structural wall of a mask may be a shell. In some forms, a shell may be faceted. In some forms a shell may be airtight. In some forms a shell may not be airtight.
Swivel (noun): A subassembly of components configured to rotate about a common axis, preferably independently, preferably under low torque. In one form, the swivel may be constructed to rotate through an angle of at least 360 degrees. In another form, the swivel may be constructed to rotate through an angle less than 360 degrees. When used in the context of an air delivery conduit, the sub-assembly of components preferably comprises a matched pair of cylindrical conduits. There may be little or no leak flow of air from the swivel in use.
Tie (noun): A structure designed to resist tension.
Vent: (noun): A structure that allows a flow of air from an interior of the mask, or conduit, to ambient air for clinically effective washout of exhaled gases. For example, a clinically effective washout may involve a flow rate of about 10 litres per minute to about 100 litres per minute, depending on the mask design and treatment pressure.
Products in accordance with the present technology may comprise one or more three-dimensional mechanical structures, for example a mask cushion or an impeller. The three-dimensional structures may be bounded by two-dimensional surfaces. These surfaces may be distinguished using a label to describe an associated surface orientation, location, function, or some other characteristic. For example, a structure may comprise one or more of an anterior surface, a posterior surface, an interior surface and an exterior surface. In another example, a seal-forming structure may comprise a face-contacting (e.g. outer) surface, and a separate non-face-contacting (e.g. underside or inner) surface. In another example, a structure may comprise a first surface and a second surface.
To facilitate describing the shape of the three-dimensional structures and the surfaces, we first consider a cross-section through a surface of the structure at a point, p. See
The curvature of a plane curve at p may be described as having a sign (e.g. positive, negative) and a magnitude (e.g. 1/radius of a circle that just touches the curve at p).
Positive curvature: If the curve at p turns towards the outward normal, the curvature at that point will be taken to be positive (if the imaginary small person leaves the point p they must walk uphill). See
Zero curvature: If the curve at p is a straight line, the curvature will be taken to be zero (if the imaginary small person leaves the point p, they can walk on a level, neither up nor down). See
Negative curvature: If the curve at p turns away from the outward normal, the curvature in that direction at that point will be taken to be negative (if the imaginary small person leaves the point p they must walk downhill). See
A description of the shape at a given point on a two-dimensional surface in accordance with the present technology may include multiple normal cross-sections. The multiple cross-sections may cut the surface in a plane that includes the outward normal (a “normal plane”), and each cross-section may be taken in a different direction. Each cross-section results in a plane curve with a corresponding curvature. The different curvatures at that point may have the same sign, or a different sign. Each of the curvatures at that point has a magnitude, e.g. relatively small. The plane curves in
Principal curvatures and directions: The directions of the normal planes where the curvature of the curve takes its maximum and minimum values are called the principal directions. In the examples of
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.
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).
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”).
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.
Planar region: A region of a surface where both of the principal curvatures are zero (or, for example, zero within manufacturing tolerances).
Edge of a surface: A boundary or limit of a surface or region.
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(1) 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).
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).
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’.)
Space curves: Unlike a plane curve, a space curve does not necessarily lie in any particular plane. A space curve may be closed, that is, having no endpoints. A space curve may be considered to be a one-dimensional piece of three-dimensional space. An imaginary person walking on a strand of the DNA helix walks along a space curve. A typical human left ear comprises a helix, which is a left-hand helix, see
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.
Unit normal vector: As the imaginary person moves along the curve, this tangent vector itself changes. The unit vector pointing in the same direction that the tangent vector is changing is called the unit principal normal vector. It is perpendicular to the tangent vector.
Binormal unit vector: The binormal unit vector is perpendicular to both the tangent vector and the principal normal vector. Its direction may be determined by a right-hand rule (see e.g.
Osculating plane: The plane containing the unit tangent vector and the unit principal normal vector. See
Torsion of a space curve: The torsion at a point of a space curve is the magnitude of the rate of change of the binormal unit vector at that point. It measures how much the curve deviates from the osculating plane. A space curve which lies in a plane has zero torsion. A space curve which deviates a relatively small amount from the osculating plane will have a relatively small magnitude of torsion (e.g. a gently sloping helical path). A space curve which deviates a relatively large amount from the osculating plane will have a relatively large magnitude of torsion (e.g. a steeply sloping helical path). With reference to
With reference to the right-hand rule of
Equivalently, and with reference to a left-hand rule (see
A surface may have a one-dimensional hole, e.g. a hole bounded by a plane curve or by a space curve. Thin structures (e.g. a membrane) with a hole, may be described as having a one-dimensional hole. See for example the one-dimensional hole in the surface of structure shown in
A structure may have a two-dimensional hole, e.g. a hole bounded by a surface. For example, an inflatable tyre has a two-dimensional hole bounded by the interior surface of the tyre. In another example, a bladder with a cavity for air or gel could have a two-dimensional hole. See for example the cushion of
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.
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.
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.
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.
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.
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.
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.
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.
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.
Although the technology herein has been described with reference to particular examples, it is to be understood that these examples are merely illustrative of the principles and applications of the technology. In some instances, the terminology and symbols may imply specific details that are not required to practice the technology. For example, although the terms “first” and “second” may be used, unless otherwise specified, they are not intended to indicate any order but may be utilised to distinguish between distinct elements. Furthermore, although process steps in the methodologies may be described or illustrated in an order, such an ordering is not required. Those skilled in the art will recognize that such ordering may be modified and/or aspects thereof may be conducted concurrently or even synchronously.
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020902667 | Jul 2020 | AU | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/AU2021/050825 | 7/29/2021 | WO |
