Patent Application
20240390627
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.
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).
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.
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. An assembly of straps comprised as part of a patient interface may be referred to as headgear.
In one type of treatment system, a flow of pressurised air is provided to a patient interface through a conduit in an air circuit that fluidly connects to the patient interface so that, when the patient interface is positioned on the patient's face during use, the conduit extends out of the patient interface forwards away from the patient's face. This may sometimes be referred to as a “tube down” configuration.
An alternative type of treatment system comprises a patient interface in which a tube that delivers pressurised air to the patient's airways also functions as part of the headgear to position and stabilise the seal-forming portion of the patient interface at the appropriate part of the patient's face. This type of patient interface may be referred to as having “conduit headgear” or “headgear tubing”. Such patient interfaces allow the conduit in the air circuit providing the flow of pressurised air from a respiratory pressure therapy device to connect to the patient interface in a position other than in front of the patient's face. One example of such a treatment system is disclosed in US Patent Publication No. US 2007/0246043, the contents of which are incorporated herein by reference, in which the conduit connects to a tube in the patient interface through a port positioned in use on top of the patient's head.
Patient interfaces incorporating headgear tubing may provide some advantages, for example avoiding a conduit connecting to the patient interface at the front of a patient's face, which may be unsightly and obtrusive.
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.
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 focused 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.
Table of noise of prior masks (ISO 17510-2:2007, 10 cmH2O pressure at 1 m)
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.
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 vent assembly for a respiratory therapy system, the vent assembly being configured in use to convey a vent flow of gases exhaled by a patient from a first volume interior to the respiratory pressure therapy system to ambient.
In one form, the vent assembly may comprise a membrane configured to flex thereby varying a position of the membrane in order to control the vent flow through one or more vent outlets to ambient. The membrane may comprise a non-planar portion contoured inwardly in the direction of vent flow, for example the non-planar portion may be substantially dome-shaped.
In certain forms the vent assembly may comprise a vent base having formed therein a vent base aperture. The vent assembly may further comprise a flexible membrane mounted within the vent assembly (for example to the vent base) and spanning across the vent base aperture, wherein the membrane has formed therein a membrane aperture to allow the vent flow to pass therethrough. The vent assembly may further comprise a vent cap connected to the vent base, wherein the vent cap is located downstream of the membrane relative to the vent flow, and wherein the vent cap is positioned in the path of the vent flow through the membrane aperture. In use, the pressure of gas in the first volume may act on the membrane such that changes in the pressure of the gas in the first volume causes the membrane to flex thereby varying a position of the membrane relative to the vent cap in order to control the vent flow through one or more vent outlets to ambient.
In examples: a) the membrane comprises a non-planar portion contoured inwardly in the direction of vent flow; b) the non-planar portion is substantially dome-shaped; c) a central region of the membrane comprises the membrane aperture and non-central regions of the membrane are impermeable to gas; d) the vent cap is mounted to the vent base to form the one or more vent outlets between the vent cap and the vent base around a periphery of the vent cap; e) the one or more vent outlets are formed as a plurality of apertures in the vent cap and wherein the membrane and vent cap are configured so that varying flex of the membrane varies the number of the plurality of apertures that are blocked by the membrane to restrict the vent flow of gas to ambient therethrough; f) the membrane and vent cap are configured so that, as the flex of the membrane increases, apertures of the plurality of apertures located closer to a periphery of the vent cap are blocked by the membrane prior to apertures of the plurality of apertures located further from the periphery of the vent cap; g) the membrane has formed therein a plurality of membrane apertures to allow the vent flow to pass therethrough; h) the vent cap is sealingly mounted to the vent base around a periphery of the vent cap; i) a side of the vent cap facing towards the membrane has a shape corresponding to a shape of the membrane when flexed; j) the membrane is mounted to the vent base around a perimeter of the membrane; k) the membrane is sealingly mounted to the vent base around the perimeter of the membrane; l) the vent assembly is configured to form part of a patient interface; m) the vent base is configured to connect to a portion of a plenum chamber of the patient interface; and/or n) the vent assembly is configured such that a vent flow rate of the vent flow of gases from the first volume to ambient is substantially constant for a range of pressures inside the first volume.
In certain forms, the vent assembly may comprise a plurality of flaps forming an aperture through which a flow of air can pass in use from an internal volume of the respiratory therapy system to surrounding ambient air. The plurality of flaps may be configured such that, in use, when the pressure inside the internal volume increases, the plurality of flaps move to a first configuration, and when the pressure inside the internal volume decreases, the plurality of flaps move to a second configuration. An area of the aperture may be greater in the second configuration compared to the first configuration.
Another aspect of the present technology comprises a vent assembly for a respiratory therapy system.
In certain forms, the vent assembly may comprise a membrane. The vent assembly may further comprise a plurality of flaps located at a central region of the membrane and forming an aperture through which a flow of air can pass in use from an internal volume of the respiratory therapy system to surrounding ambient air. The membrane and the plurality of flaps may be configured such that, in use when the pressure inside the internal volume increases, the plurality of flaps move relative to the membrane to a first configuration, and when the pressure inside the internal volume decreases, the plurality of flaps move relative to the membrane to a second configuration. An area of the aperture may be greater in the second configuration compared to the first configuration.
In certain forms, the vent assembly may comprise a membrane having a concave inner surface and a convex outer surface. The vent assembly may further comprise a plurality of flaps located at a central region of the membrane and forming an aperture through which a flow of air can pass in use from an internal volume of the respiratory therapy system to surrounding ambient air. The membrane may be arranged with the concave inner surface facing the internal volume of the respiratory therapy system and the convex outer surface facing the surrounding ambient air. The membrane and the plurality of flaps may be configured such that, in use when the pressure inside the internal volume increases, the plurality of flaps move relative to the membrane to a first configuration, and when the pressure inside the internal volume decreases, the plurality of flaps move relative to the membrane to a second configuration. An area of the aperture may be greater in the second configuration compared to the first configuration. At least an upstream portion of the membrane may be positioned further from the centre of the aperture compared to a downstream portion of the membrane, the upstream portion being located upstream in relation to the flow of air and the downstream portion being located downstream in relation to the flow of air.
In examples: a) the plurality of flaps extend from the membrane in a radially inwards direction towards the aperture; b) the plurality of flaps are located around an outer circumference of the central aperture; c) the plurality of flaps have a curved shape; d) the curvature of a surface of the flaps contiguous with the inner surface of the membrane is greater than a curvature of a surface of the flaps contiguous with the outer surface of the membrane; e) the flaps have a thickness that varies along its length; f) the flaps have a greater thickness at a radially outer region compared to a radially inner region; g) the downstream portions of the flaps have a greater thickness than the upstream portions; h) the membrane comprises the plurality of flaps; i) the membrane defines a plurality of slits forming the plurality of flaps therebetween; j) the slits are oriented radially with respect to the membrane; k) the flaps are formed from a flexible and resilient material; l) the membrane is formed from a flexible and resilient material; m) the membrane is substantially dome-shaped; n) an outer region of the membrane connects to a vent base; o) the vent assembly is comprised as a part of a patient interface and the vent base connects to a portion of the patient interface; p) the vent base connects to a portion of a plenum chamber of the patient interface; q) the vent base connects to a portion of an elbow; r) the vent base is formed from a material that is relatively inflexible compared to the membrane; s) the vent assembly further comprises a vent cap; t) the vent cap is located downstream of the membrane; u) an inner surface of the vent cap has a curvature that is similar to the curvature of the outer surface of the membrane; v) the vent cap is formed from a material that is relatively inflexible compared to the membrane; w) the vent assembly further comprises a vent outlet located adjacent a radially outer region of the vent cap; x) the vent outlet is formed by one or more gaps between the vent cap and the vent base; y) the vent assembly is configured so that the flow of air through the aperture in the second configuration is approximately equal to the flow of air through the aperture in the first configuration; and/or z) the vent assembly is configured so that the flow of air through the aperture is approximately equal for a range of pressures of air in the internal volume in use.
In certain forms, the vent assembly may comprise a plurality of flaps forming an aperture through which a flow of air can pass in use from an internal volume of the respiratory therapy system to surrounding ambient air. The plurality of flaps may be separated by a plurality of slits. The plurality of flaps may be configured such that, in use, when the pressure inside the internal volume increases, the plurality of flaps move to a first configuration, and when the pressure inside the internal volume decreases, the plurality of flaps move to a second configuration. An area of the aperture may be greater in the second configuration compared to the first configuration.
In certain forms, the vent assembly may comprise a membrane, and a plurality of flaps located at a central region of the membrane and forming an aperture through which a flow of air can pass in use from an internal volume of the respiratory therapy system to surrounding ambient air. The membrane may define a plurality of slits forming the plurality of flaps therebetween. The membrane and the plurality of flaps may be configured such that, in use when the pressure inside the internal volume increases, the plurality of flaps move relative to the membrane to a first configuration, and when the pressure inside the internal volume decreases, the plurality of flaps move relative to the membrane to a second configuration. An area of the aperture may be greater in the second configuration compared to the first configuration.
In examples: a) the slits are oriented radially with respect to the membrane; and/or b) the membrane has a concave inner surface and a convex outer surface, and wherein the membrane is arranged with the concave inner surface facing the internal volume of the respiratory therapy system and the convex outer surface facing the surrounding ambient air.
In certain forms, the vent assembly may comprise a membrane, having a concave inner surface and a convex outer surface. The vent assembly may further comprise a plurality of flaps located at a central region of the membrane and forming an aperture through which a flow of air can pass in use from an internal volume of the respiratory therapy system to surrounding ambient air. The membrane may be arranged with the concave inner surface facing the internal volume of the respiratory therapy system and the convex outer surface facing the surrounding ambient air. The membrane and the plurality of flaps may be configured such that, in use, when the pressure inside the internal volume increases, the plurality of flaps move relative to the membrane to a first configuration and when the pressure inside the internal volume decreases, the plurality of flaps move relative to the membrane to a second configuration. An area of the aperture may be greater in the second configuration compared to the first configuration. At least a portion of the membrane may be located upstream, in relation to the flow of air, of the aperture.
Another aspect of one form of the present technology comprises a vent assembly for a respiratory therapy system for providing respiratory pressure therapy to a patient, the vent assembly being configured in use to convey a vent flow of gases from a first volume interior to the respiratory therapy system to ambient, the vent assembly comprising:
In further examples:
In further examples:
In further examples:
Another aspect of one form of the present technology comprises a vent assembly for a respiratory therapy system for providing respiratory pressure therapy to a patient, the vent assembly being configured in use to convey a vent flow of gases from a first volume interior to the respiratory therapy system to ambient, the vent assembly comprising:
In examples:
Another aspect of one form of the present technology comprises a vent assembly for a respiratory therapy system for providing respiratory pressure therapy to a patient, the vent assembly being configured in use to convey a vent flow of gases from a first volume interior to the respiratory therapy system to ambient, the vent assembly comprising:
In examples:
Another aspect of one form of the present technology comprises a vent assembly for a respiratory therapy system for providing respiratory pressure therapy to a patient, the vent assembly being configured in use to convey a vent flow of gases from a first volume interior to the respiratory therapy system to ambient, the vent assembly comprising:
In examples:
Another aspect of one form of the present technology comprises a vent assembly for a respiratory therapy system for providing respiratory pressure therapy to a patient, the vent assembly being configured in use to convey a vent flow of gases from a first volume interior to the respiratory therapy system to ambient, the vent assembly comprising:
In examples:
Another aspect of certain forms of the technology is a patient interface for use in a respiratory therapy system. The patient interface may be configured to deliver a flow of gas at positive pressure to a patient's airways. The patient interface may comprise a vent assembly according to another aspect of the technology.
An aspect of one form of the present technology is a patient interface for use in a respiratory therapy system. The patient interface may comprise 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. The patient interface may further comprise 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. The patient interface may also comprise a vent assembly according to another aspect of the present technology. The vent assembly may allow a flow of gases exhaled by the patient from an interior of the plenum chamber to ambient, said vent assembly being sized and shaped to maintain the therapeutic pressure in the plenum chamber in use. The patient interface may also be configured to allow the patient to breath from ambient through their mouth in the absence of a flow of pressurised air through the plenum chamber inlet port, or the patient interface is configured to leave the patient's mouth uncovered.
In some forms, the plenum chamber comprises the vent assembly.
An aspect of one form of the present technology is a respiratory therapy system comprising a patient interface according to another aspect of the present technology. The respiratory therapy system may further comprise at least one air circuit for supplying the flow of gas at the therapeutic pressure to the patient interface.
Another aspect of the technology is an air circuit for use in a respiratory therapy system. The air circuit may be configured to deliver a supply of gas from an RPT device to a patient interface. The air circuit may comprise a vent assembly according to another aspect of the technology.
An aspect of one form of the present technology is a respiratory therapy system comprising a vent assembly according to another aspect of the present technology. The respiratory therapy system may further comprise at least one air circuit for supplying the flow of gas at the therapeutic pressure to the patient interface. The respiratory therapy system may further comprise a patient interface. The patient interface may comprise 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. The patient interface may further comprise 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. The patient interface may be configured to allow the patient to breath from ambient through their mouth in the absence of a flow of pressurised air through the plenum chamber inlet port, or the patient interface may be configured to leave the patient's mouth uncovered.
An aspect of one form of the present technology is a respiratory therapy system comprising at least one air circuit for supplying the flow of gas at the therapeutic pressure to the patient interface. The respiratory therapy system may further comprise a patient interface. The patient interface may comprise 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. The patient interface may further comprise 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. The patient interface may be configured to allow the patient to breath from ambient through their mouth in the absence of a flow of pressurised air through the plenum chamber inlet port, or the patient interface may be configured to leave the patient's mouth uncovered.
In some forms, the air circuit comprises a vent assembly according to another aspect of the present technology.
Another aspect of the technology is an elbow for use in a respiratory therapy system. The elbow may be configured to deliver a supply of gas from an air circuit to a plenum chamber of a patient interface. The elbow may be comprised as part of the patient interface or may connect to the patient interface in use. The elbow may comprise a vent assembly according to another aspect of the technology.
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, such as that shown in
As shown in
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, the non-invasive patient interface 3000 comprises a seal-forming structure 3100 that forms a seal in use to an upper lip region (e.g. the lip superior), to the patient's nose bridge or at least a portion of the nose ridge above the pronasale, and to the patient's face on each lateral side of the patient's nose, for example proximate the patient's nasolabial sulci. The patient interface 3000 shown in
In one form the patient interface 3000 comprises a seal-forming structure 3100 that forms a seal in use on a patient's chin-region (which may include the patient's lip inferior and/or a region directly inferior to the lip inferior), to the patient's nose bridge or at least a portion of the nose ridge superior to the pronasale, and to cheek regions of the patient's face. The patient interface 3000 shown in
In one form the patient interface 3000 comprises a seal-forming structure 3100 that forms a seal in use on a patient's chin region (which may include the patient's lip inferior and/or a region directly inferior to the lip inferior), to an inferior and or anterior surface of the patient's pronasale and to the patient's face on each lateral side of the patient's nose, for example proximate the nasolabial sulci. The seal-forming structure 3100 may also form a seal against a patient's lip superior. A patient interface 3000 having this type of seal-forming structure may have a single opening configured to deliver a flow of air or breathable gas to both nares and mouth of a patient, may have an oral hole configured to provide air or breathable gas to the mouth and a nasal hole configured to provide air or breathable gas to the nares, or may have an oral hole for delivering air to the patient's mouth and two nasal holes for delivering air to respective nares. This type of patient interface 3000 may be known as an ultra-compact full face mask and may comprise an ultra-compact full face cushion.
In one form, for example as shown in
The shape of the seal-forming structure 3100 may be configured to match or closely follow the underside of the patient's nose and may not contact a nasal bridge region of the patient's nose or any portion of the patient's nose superior to the pronasale. In one form of nasal cradle cushion, the seal-forming structure 3100 comprises a bridge portion dividing the opening into two orifices, each of which, in use, supplies air or breathable gas to a respective one of the patient's nares. The bridge portion may be configured to contact or seal against the patient's columella in use. Alternatively, the seal-forming structure 3100 may comprise a single opening to provide a flow or air or breathable gas to both of the patient's nares.
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.
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. The positioning and stabilising structure 3300 may comprise and function as “headgear” since it engages the patient's head in order to hold the patient interface 3000 in a sealing position.
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 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 some forms of the present technology, the positioning and stabilising structure 3300 comprises one or more headgear tubes 3350 that deliver pressurised air received from a conduit forming part of the air circuit 4170 from the RPT device to the patient's airways, for example through the plenum chamber 3200 and seal-forming structure 3100. In the form of the present technology illustrated in
Since air can be contained and passed through headgear tubing in order to deliver pressurised air from the air circuit 4170 to the patient's airways, the positioning and stabilising structure 3300 may be described as being inflatable. It will be understood that an inflatable positioning and stabilising structure 3300 does not require all components of the positioning and stabilising structure 3300 to be inflatable. For example, in the example shown in
In the form of the present technology illustrated in
In the form of the technology shown in
The tubes 3350 may be formed from a flexible material, such as an elastomer, e.g. silicone or TPE, or from one or more textile and/or foam materials. The tubes 3350 may have a preformed shape and may be able to be bent or moved into another shape upon application of a force but may return to the original preformed shape in the absence of said force. The tubes 3350 may be generally arcuate or curved in a shape approximating the contours of a patient's head between the top of the head and the nasal or oral region.
As described in U.S. Pat. No. 6,044,844, the contents of which are incorporated herein, the tubes 3350 may be crush resistant to avoid the flow of breathable gas through the tubes being blocked if either is crushed during use, for example if it is squashed between a patient's head and pillow. Crush resistant tubes may not be necessary in all cases as the pressurised gas in the tubes may act as a splint to prevent or at least restrict crushing of the tubes 3350 during use. A crush resistant tube may be advantageous where only a single tube 3350 is present as if the single tube becomes blocked during use the flow of gas would be restricted and therapy will stop or reduce in efficacy. In some examples, the tubes 3350 may be sized such that each tube 3350 is able to provide sufficient flow of gas to the plenum chamber 3200 on its own should one of the tubes 3350 become blocked.
Each tube 3350 may be configured to receive a flow of air from the connection port 3600 on top of the patient's head and to deliver the flow of air to the seal-forming structure 3100 at the entrance of the patient's airways. In the example shown in
In certain forms of the present technology the patient interface 3000 is configured such that the connection port 3600 can be positioned in a range of positions across the top of the patient's head so that the patient interface 3000 can be positioned as appropriate for the comfort or fit of an individual patient. In some examples, the headgear tubes 3350 are configured to allow movement of an upper portion of the patient interface 3000 (e.g. a connection port 3600) with respect to a lower portion of the patient interface 3000 (e.g. a plenum chamber 3200). That is, the connection port 3600 may be at least partially decoupled from the plenum chamber 3200. In this way, the seal-forming structure 3100 may form an effective seal with the patient's face irrespective of the position of the connection port 3600 (at least within a predetermined range of positions) on the patient's head.
As described above, in some examples of the present technology the patient interface 3000 comprises a seal-forming structure 3100 in the form of a cradle cushion which lies generally under the nose and seals to an inferior periphery of the nose (e.g. an under-the-nose cushion). The positioning and stabilising structure 3300, including the tubes 3350 may be structured and arranged to pull the seal-forming structure 3100 into the patient's face under the nose with a sealing force vector in a posterior and superior direction (e.g. a posterosuperior direction). A sealing force vector with a posterosuperior direction may facilitate the seal-forming structure 3100 forming a good seal to both the inferior periphery of the patient's nose and the anterior-facing surfaces of the patient's face on either side of the patient's nose and the patient's lip superior.
In certain forms of the present technology, the patient interface 3000 may comprise a connection port 3600 located proximal to a superior, lateral or posterior portion of a patient's head. For example, in the form of the present technology illustrated in
In certain forms of the present technology, the positioning and stabilising structure 3300 comprises at least one headgear strap acting in addition to the tubes 3350 to position and stabilise the seal-forming structure 3100 at the entrance to the patient's airways. As shown in
In the example shown in
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.
In certain aspects of the present technology, a vent assembly 6000 is provided that is configured to form or provide a vent 3400 for the respiratory therapy system in use.
As is the case with the forms of the technology shown in
In some forms of the technology, the cushion module 3150 may be provided with a plurality of vent assemblies 6000. The plurality of vent assemblies 6000 may be arranged in a line, in a circular arrangement or along a plurality of lines, along one or more parts of the cushion module 3150, for example.
In one form of the present technology, the patient interface 3000 is configured so that, in use, the vent assembly 3400 is located proximate the airway entrance of a patient, for example proximate the nasal entrance as in the case of the patient interface 3000 of
It has been explained above that, in certain forms of the technology, for example the form of the technology shown in
In some forms of the technology, the vent assembly 6000 may be located in the air circuit 4170 or in a decoupling structure, e.g., a swivel or elbow.
The vent assembly 6000 for a respiratory pressure therapy system may be configured in use to convey a vent flow of gases exhaled by a patient from a first volume, which is interior to the respiratory pressure therapy system, to ambient. The first volume may be supplied with a pressurised flow of gas from the RPT device 4000 in use, and also may be a volume that receives exhaled gas from the patient. The first volume may depend on the location of the vent assembly 6000 within the respiratory pressure therapy system. For instance, in forms of the technology where the vent assembly 6000 is formed as part of the plenum chamber 3200, the first volume may be or at least include the volume inside the plenum chamber 3200. In other forms, the first volume may be formed, at least in part, by a volume inside, for example headgear tubes 3350, air circuit 4170, a decoupling structure or elbow, in addition to the volume inside the plenum chamber 3200.
In one form of the present technology, the vent assembly 6000 may comprise a vent base 6100 having formed therein a vent base aperture 6110. The vent assembly 6000 may further comprise a flexible membrane 6200 mounted within the vent assembly 6000, for example to the vent base 6100, and spanning across the vent base aperture 6110. The membrane 6200 may have formed therein a membrane aperture 6210 to allow the vent flow to pass through the membrane 6200. The vent assembly 6000 may also comprise a vent cap 6300 connected to the vent base 6100, for example mounted directly to the vent base 6100 or connected to it via one or more intermediate components. The vent cap 6300 may be located downstream of the membrane 6200 relative to the vent flow. The vent cap 6300 may be positioned in the path of the vent flow through the membrane aperture 6210.
In the case of both the vent assembly 3400 shown in
A patient interface 3000 may require a vent flow rate that is at least large enough to “wash out” exhalate from the plenum chamber 3200 (to prevent rebreathing of exhaled air and the associated carbon dioxide) for the lowest therapy pressure at which a patient interface 3000 may be used. This requirement may be based on the size of the plenum chamber 3200. In a vent with fixed size orifice(s) and no moving parts, when the pressure of the air entering the first volume of the vent assembly 6000 is higher, as may be required by some patients for appropriate treatment, more air is forced to exit the vent outlet(s) 6400 to ambient such that at higher treatment pressures, more air is typically lost by the system due to an increased vent flow rate. The respiratory pressure therapy device generating the flow of air needs to compensate for this loss, resulting in increased power consumption. Furthermore, the higher vent flow rates may be noisy or uncomfortable to the patient or a bed partner. In one form of the present technology, the configuration (e.g. shape, size, orientation and/or position) adopted by the membrane 6200 is based on the pressure of gas in the first volume. A higher regulated air pressure entering the first volume will exert more force on the membrane 6200, urging the membrane closer to the vent cap 6300, such that the vent outlet(s) 6400 are occluded to a greater extent, reducing what would otherwise have been an increased flow rate through the vent outlet(s) 6400 to ambient.
The way in which the configuration of the membrane 6200 varies with changes in pressure, and consequently the way in which the vent flow rate changes with pressure, may be determined based on certain characteristics of the membrane 6200. Examples of such characteristics and how they may be varied will be discussed further below. In certain forms, the vent assembly 6000 may be configured so that, in use, the vent flow rate of exhaled air from the first volume through the vent assembly 6000 to ambient is substantially constant for a range of pressures inside the first volume. In some forms the vent assembly 6000 is configured such that in use the vent flow rate from the first volume increases with increasing pressure to a lesser extent than it would increase in a fixed-size aperture vent.
In the example shown in
In certain forms of the present technology, since the plurality of flaps 6700 are in contact with the first volume, the pressurised air in the first volume is able to act on the flaps 6700 and cause them to move. The movement of the flaps 6700 may change the area of the central aperture 6800. Consequently, the configuration adopted by the plurality of flaps 6700 is based on the pressure of gas in the first volume. The central aperture 6800 may in some forms be the vent outlet to ambient, such that changing the area of the central aperture 6800 changes the flow rate through the vent outlet to ambient.
The plurality of flaps 6700, along with the membrane 6200 in forms of the technology comprising a membrane 6200, may be configured such that, in use when the pressure inside the first volume increases, the plurality of flaps 6700 move to a first configuration and when the pressure inside the first volume decreases, the plurality of flaps move to a second configuration. An area of the central aperture 6800 is greater in the second configuration compared to the first configuration. The movement of the flaps 6700 may be movement relative to the membrane 6200. Alternatively, in some forms, the membrane 6200 may move, at least in part, with the flaps 6700.
The way in which the configuration of the plurality of flaps 6700 varies with changes in pressure, and consequently the way in which the vent flow rate changes with pressure, may be determined based on certain characteristics of the plurality of flaps 6700. Examples of such characteristics and how they may be varied will be discussed further below. In certain forms, the vent assembly 6000 may be configured so that, in use, the vent flow rate of exhaled air from the first volume through the vent assembly 6000 to ambient is substantially constant for a range of pressures inside the first volume. Operation of the vent assembly 6000 and the configuration of the plurality of flaps 6700 is discussed further below.
The membrane 6200 may be constructed and arranged to allow the regulation of a vent flow of exhaled gas from the airway of a patient leaving the vent assembly 6000 to ambient.
In the example of the technology shown in
In certain forms, the membrane 6200 spans across the vent base aperture 6110. The membrane 6200 may be positioned such that it bridges the vent base aperture 6110, for instance the periphery of the membrane 6200 may be mounted to the vent base 6100 around the vent base aperture 6110 such that the central region of the membrane 6200 is positioned over the vent base aperture 6110. The membrane 6200 may therefore at least partially cover the vent base aperture 6110 such that it at least partially blocks or obstructs the flow path of the vent flow of gas from the vent base aperture 6110.
In the forms of the technology illustrated, the membrane 6200 is formed to be flexible such that it can flex or bend as the pressure in the first volume increases and decreases. For example, the membrane 6200 may be formed from a flexible material. The material may also be impermeable to gas. Examples of suitable materials include silicone or rubber. The flexibility of the membrane 6200 may be affected by a variety of factors, including the material of the membrane and/or the thickness of the membrane, which in some forms may be in the range 0.45 mm-0.55 mm and in some forms may be approximately 0.5 mm. In some forms, as described below, where the membrane moves as pressure in the first volume changes, the flexibility may be a characteristic of the membrane 6200 that affects the rate of vent flow through the vent assembly 6000.
In some forms, the membrane 6200 may be entirely or substantially planar. In alternative forms, the membrane 6200 may comprise a non-planar portion 6220. The non-planar portion 6220 may be contoured inwardly in the direction of vent flow. That is, the side of the non-planar portion 6220 facing towards the first volume may be positively curved (i.e. concave) and the side of the non-planar portion 6220 facing away from the first volume may be negatively curved (i.e. convex). The central region of the membrane 6200 may comprise the non-planar portion 6220. The membrane may have a concave inner surface and a convex outer surface. In the illustrated forms, the concave inner surface is on the side of the non-planar portion 6220 facing towards the first volume, e.g. the internal volume of the respiratory therapy system, and the convex outer surface is on the side of the non-planar portion 6220 facing away from the first volume, i.e. facing the surrounding ambient air. In this way, the non-planar portion 6220 may be substantially dome-shaped, as is the case in the forms of the technology shown in
The membrane 6200 may comprise the non-planar portion 6220 even when there is no pressure difference between the first volume on one side of the membrane 6200 and ambient on the opposite side of the membrane 6200, i.e. the resting position of the membrane 6200 when not in use comprises the non-planar portion 6220. The non-planar portion 6220 may substantially span the vent base aperture 6110. The size of the non-planar portion 6220 may therefore correspond to the size of the vent base aperture 6110.
The non-planar portion 6220 may be the portion of the membrane 6200 that flexes when the pressure of the gas in the first volume acts on the membrane 6200. The non-planar portion 6220 may therefore flex in a direction away from the first volume and towards the cap 6300.
In other forms, the membrane 6200 may be substantially planar in the absence of forces on the membrane, and the force exerted by the pressure of the gas in the first volume may cause the membrane 6200 to flex in a direction away from the first volume and towards the cap 6300.
As explained above, the membrane 6200 may have formed therein a membrane aperture 6210 to allow the vent flow to pass through the membrane 6200. In the form of the technology shown in
In the form of the technology shown in
In the embodiment shown in
The shape and structure in combination with the material of the membrane 6200 may be configured such the membrane 6200 is flexible and/or resilient. For example, the membrane 6200 may be formed from a relatively soft material such as silicone or rubber.
In vent assemblies 6000 having one or more flaps 6700, the membrane 6200 and the plurality of flaps 6700 may be integrally formed, as shown in the examples shown in
The plurality of flaps 6700 may be constructed and arranged to allow the regulation of a vent flow of exhaled gas from the airway of a patient that passes through the vent assembly 6000 to ambient.
In the examples shown in
In the examples shown in
The plurality of flaps 6700 may each be shaped like a sheet, such that they are relatively thin in one direction. The plurality of flaps 6700 may have a curved shape, i.e. a non-planar shape. The plane of the sheet of the plurality of flaps 6700 may be curved in one or more direction, for instance it may curve towards the first volume, i.e. the inner surface of the flaps 6700 (located on an upstream side of the flaps 6700 and facing the first volume) may be concave and the outer surface of the flaps (opposite the inner surface, located on a downstream side of the flaps 6700 and facing away from the first volume) may be convex. The curved shape of the plurality of flaps is shown in cross-section in
The thickness of the flaps 6700 may be similar to that of the membrane 6200 and, in some forms the inner surface of the flaps 6700 may be contiguous with the inner surface of the membrane 6200 and the outer surface of the flaps 6700 may be contiguous with the outer surface of the membrane 6200. In the illustrated forms, the inner and outer surfaces of the plurality of flaps 6700 have a shape of a sector of an annulus in plan view (e.g. when projected onto a plane), while in other forms they may have another shape, for instance square, trapezoidal, triangular or rectangular when projected onto a plane.
The plurality of flaps 6700 may have a substantially arc-shaped cross-section as shown in
Each flap 6700 may have a thickness that varies along its length. For example, the flaps 6700 may taper towards their radially inner end, i.e. they may have a greater thickness at a radially outer region compared to a radially inner region. Due to the orientation of the flaps, this means that the downstream portions of the flaps 6700 may have a greater thickness than the upstream portions. The taper of the flaps 6700 may assist flaps 6700, in particular the radially inner end of the flaps 6700, to be more responsive to pressure changes in the first volume compared to the thicker, radially outer portions of the flaps, i.e. the radially inner end of the flaps 6700 may move more easily in response to pressure changes in the first volume than the radially outer portions of the flaps. The Durometer hardness of the material forming the flaps 6700 may also affect how responsive the flaps 6700, or portions of the flaps 6700, are to pressure changes. For instance a harder flap 6700, or portion of the flap 6700, may be stiffer and therefore less responsive to pressure changes in the first volume compared to a less hard flap 6700, or portion of the flap 6700.
In different forms of the technology, the shape, including the thickness and arc shape, of the plurality of flaps 6700 may be selected based on the amount the flaps 6700 are desired to move as pressure changes. This is discussed further below.
In certain forms, each of the plurality of flaps 6700 may have the same shape and size as the other flaps, as in the illustrated examples, while in other forms of the technology the flaps may have different shapes and/or sizes to alter the function of the flaps 6700 and therefore the flow of air through the vent assembly 6000.
In certain forms, the plurality of flaps 6700 are arranged to form the central aperture 6800 between their radially inward free ends (which may take the form of a tip), and may be located around an outer circumference of the central aperture 6800. The central aperture 6800 may be substantially circular in cross-section in some forms, while in other forms it may have an alternate shape, for instance square, rectangular, or oval. The shape of the central aperture 6800 may be determined by the shape of the plurality of flaps 6700, particularly their free ends. In the forms of the technology illustrated, the portion of the plurality of flaps 6700 adjacent the central aperture may have an arc-shape, curved circumferentially around the longitudinal central axis of the membrane 6200. The arc-shape can be seen in
Each of the plurality of flaps 6700 may have a fixed end 6701 that is connected to the membrane 6200, for example to an inner surface of a radially inner region of the membrane 6200, or to another portion of the respiratory therapy system for instance the inner surface in a wall of the plenum chamber 3200 or seal-forming structure 3100. That is, in some forms, the vent structure 3400 may be absent a membrane and the flaps 6700 may be mounted directly in an aperture of another component of the patient interface 3000. Each of the plurality of flaps 6700 may also have a free end 6702 that is opposite the fixed end 6701 and is not connected to anything. The fixed end 6701 may be a downstream portion of the flaps 6700 and the free end 6702 may be an upstream portion of the flaps 6700 relative to the straight arrows of
In some forms, alternatively or in addition to the rotation about the fixed ends 6701, the shape of the flaps 6700 may change between the first configuration and the second configuration, for example through elastic deformation of the flaps 6700. In some forms the curvature of the plurality of flaps 6700 may decrease as they move from the second configuration to the first configuration, i.e. the flaps 6700 may become less arched or may flatten due to the action of the pressurised air in the first volume.
In use when there is no pressurised flow of air provided to the first volume, the plurality of flaps 6700 may be in a rest configuration. In use the plurality of flaps 6700 may be able to move between a plurality of configurations, or a continuum of configurations, as the pressure in the first volume changes, whereby each of the different configurations provide a different area of the central aperture 3800 and therefore vary the amount of flow of air exiting the vent 3400. The first and second configurations described earlier are configurations of the plurality of configurations.
In some forms the shape and the structure in combination with the material of the plurality of flaps 6700 may be configured such that the flaps 6700 are resilient such that they return towards the rest position when the pressure in the first volume decreases. In other forms, a spring mechanism may act on the flaps such that they return towards the rest position when the pressure in the first volume decreases.
In the example shown in
The shape and structure of the flaps 6700, in combination with the material of the plurality of flaps 6700 may be configured such the plurality of flaps 6700 are flexible and/or resilient. In certain forms, the plurality of flaps 6700 may be formed from a silicone or rubber, for example.
In certain forms of the technology, the vent assembly 6000 may also comprise a vent cap 6300 mounted to the vent base. The vent cap 6300 may be located downstream of the membrane 6200 and the plurality of flaps 6700 relative to the vent flow. The vent cap 6300 may be positioned in the path of the vent flow after it has passed through the central aperture 6800.
In other forms, for example the form shown in
In examples of the present technology in which the vent assembly 6000 comprises a vent cap 6300, the vent cap 6300 may be mounted to the vent base 6100 and located downstream of the membrane 6200 relative to the vent flow. The vent cap 6300 may be positioned in the path of the vent flow through the membrane aperture 6210. The vent cap 6300 may therefore be configured to direct vent flow through at least a part of the vent assembly 6000. In some forms, a first surface, inner surface 6310 of the vent cap 6300 faces towards the membrane 6200. The first surface 6310 may be in contact with vent flow that has passed through the membrane aperture 6210 and flows through the space between the vent cap 6300 and the membrane 6200. In some forms, as shown in
As shown in the embodiments in
In some forms, the second, outer surface 6320 has a different shape to the first surface 6310. In some forms, for instance that shown in
In certain forms of the technology, the first, inner surface 6310 may be a substantially smooth surface, such that it reduces the amount of turbulence created in the vent flow as it passes along adjacent to the first surface 6310 towards the vent outlet(s) 6400 compared to forms in which the first surface 6310 has protrusions or ridges. In some forms, the vent flow is directed by the vent cap towards an outer periphery of the vent cap 6300 where the vent outlet(s) 6400 are located. In some forms, as shown in
In some forms, the vent flow exits the vent assembly 6000 in a direction perpendicular to the direction of vent flow entering the vent base aperture 6110. This direction may be parallel to the surface of the surrounding patient interface 3000, for instance the plenum chamber 3200. In other forms, like that shown in
The vent cap 6300 may substantially cover the membrane 6200 forming a vent gap 6600 therebetween, discussed further below. In alternative embodiments, the vent cap 6300 may be substantially planar and have a recess in the surface of the vent cap 6300 facing the membrane 6200. The recess may have a shape that substantially corresponds to the non-planar portion 6220 of the membrane 6200.
The vent cap 6300 is formed from a substantially hard material and constructed in a shape that results in the vent cap being substantially inflexible when subject to the forces encountered during typical use, and in some forms may be formed from a polycarbonate. The vent cap 6300 therefore may have a constant shape during pressure changes in the first volume. The vent base 6100 may also be formed from the same material as the vent cap 6100 or another material and in a shape that renders the vent base 6100 similarly inflexible during typical use.
The vent cap 6300 may be mounted to the vent base 6100 at a region around the periphery of the vent cap 6300. In some forms of the technology the vent cap 6300 is mounted at a single region on the periphery of the vent cap 6300. In other forms the vent cap 6300 may be mounted at a plurality of regions on the periphery of the vent cap 6300. The vent cap 6300 may be mounted to the base by several struts between the periphery of the vent cap 6300 and the upper region 6120 of the vent base 6100 to form gaps between the outer periphery of the vent cap 6300 and the vent base 6100. The gaps formed between these struts may form vent outlets 6400. In the form of the technology as shown in
In some forms of the vent assembly 3400, in use, the membrane 6200 may be sufficiently flexible that the pressure of the gas in the first volume acts on the membrane 6200 and causes the membrane 6200 to flex, e.g. bulge outwardly, particularly the non-planar portion of the membrane, particularly at higher pressures. The varying flex in the membrane 6200 varies a position of the membrane 6200 or a portion or portions thereof relative to the vent cap 6300, which changes the height of the vent gap 6600. As described above, this mechanism (in addition to or combination with the movement of any flaps 6700 that may be present) may be used to control the vent flow through one or more vent outlets to ambient, e.g. the rate of vent flow. Generally, when the pressure of the gas in the first volume increases the membrane 6200 flexes into a position closer to the vent cap 6300 and such that there is a reduced vent flow through the vent outlet(s) than would be the case at the same pressure if the membrane did not move closer to the vent cap.
In these forms of the technology, as the vent membrane 6200 flexes the size (e.g. cross sectional area) of the vent gap 6600 changes which varies the amount of vent flow through the vent gap 6600 and therefore the rate of vent flow exiting the vent outlet. The vent cap 6300 and the membrane 6200 may be positioned far enough apart such that the membrane 6200 never fully closes or blocks the vent gap 6600, even at relatively high pressures typically encountered during use in the first volume. Similarly, the central aperture 6800 may never fully close or be blocked off by the plurality of flaps 6700.
The way in which the configuration of the membrane 6200 varies with changes in pressure, and consequently the way in which the vent flow rate changes with pressure, may be determined based on certain characteristics of the membrane 6200. Examples of such characteristics and how they may be varied will be discussed further below. In certain forms, the vent assembly 6000 may be configured so that, in use, the vent flow rate of exhaled air from the first volume through the vent assembly 6000 to ambient is substantially constant for a range of pressures inside the first volume.
In some forms, the membrane 6200 may be substantially planar in the absence of forces on the membrane, and the force exerted by the pressure of the gas in the first volume may cause the membrane 6200 to flex such that the size and shape of the membrane aperture and/or the vent gap 6600, as the case may be, changes.
The vent structure 3400 may comprise or define one or more vent outlets where the vent flow from the respiratory pressure therapy system leaves the vent structure 3400 to ambient.
In the form of the technology shown in
In some forms of the technology, a single vent outlet 6400 is formed around at least a portion of the periphery of the vent cap 6300. In other forms of the technology, one or more struts may be formed between the vent cap 6300 and the vent base 6100 around the periphery of the vent cap 6300 to form a plurality of vent outlets 6400. The struts may be equally spaced around the periphery of the vent cap 6300. The struts may help to separate the flow paths of the vent flow and the struts may have a streamlined cross-sectional shape, which may assist in reducing turbulence and noise of vent flow exiting the vent assembly 6000. The vent flow of gas may additionally or alternatively be discharged form vent cap holes 6301 or from a central hole 6302 shown in
In the example shown in
In the form of the technology shown in
In some forms of the technology, as shown in
In the form of the technology shown in
As the pressure of the gas in the first volume increases, the membrane 6200 flexes in the direction of the vent flow to reduce the size of the vent gap 6600 to reduce the vent flow exiting the vent outlet 6400. Similarly, as the pressure of gas in the first volume decreases, the membrane 6200 relaxes, increasing the size of the vent gap 6600. This allows the vent assembly 6000 to be configured in a manner that means the vent flow at a given pressure can be controlled. For example, in some forms, the vent assembly 6000 may be configured so that a relatively constant flow exiting the vent assembly 6000 may be achieved for a variety of pressures in the first volume. The pressure-flow relationship of the form of the technology in
In the form of the technology shown in
In the form of the technology shown in
In the forms of the technology shown in
As mentioned above,
In some forms, the flange 6240 may connect directly to the positioning and stabilising structure 3300, and in some forms directly to the rigidiser arms 3310. A portion of the flange 6240 may connect to an end region of the rigidiser arms 3310.
In the form of the technology shown in
It has already been explained that the vent flow rate of a vent assembly 6000 according to certain forms of the technology may depend on the pressure of the gas within the first volume. The manner in which the vent flow rate depends on the pressure may be known as the pressure-flow relationship of the vent assembly 6000. The pressure-flow relationship for any vent assembly 6000 may be determined by certain aspects of the configuration of the membrane 6200 of that vent assembly 6000. When designing or manufacturing a vent assembly 6000, any one or more of those aspects of the configuration may be selected in order to provide the desired pressure-flow relationship. The selection of these characteristics, and configuring the membrane 6200 accordingly, may be referred to as tuning the vent assembly 6000. Tuning a vent assembly 6000 enables the vent flow rate for any given air pressure inside the first volume to be selected as desired.
In some forms, tuning the vent assembly 6000 may involve configuring the vent assembly 6000 to provide the desired pressure-flow relationship during inhalation and, separately, the desired pressure-flow relationship during exhalation.
The desired pressure-flow relationship may be determined based on various factors including, but not limited to: the nature of the patient interface 3000; the nature of the RPT device 4000; a patient's treatment preferences; a clinician's treatment preferences; and/or the nature of the respiratory treatment.
One factor that affects the vent flow rate at a given pressure, and therefore the overall pressure-flow relationship of the vent assembly 6000, is the degree that the vent outlet(s) 6400 are occluded at the given pressure. Two non-limiting examples of design characteristics that can affect the level of occlusion of the vent outlet(s) 6400 at a given pressure include: the ratio between the effective vent opening area when the membrane 6200 is flexed compared to when it is in a neutral position; and the resistance of the membrane 6200 to flexing. Exemplary ways in which these characteristics may be varied in different forms of the technology will now be described. These design variants, as well as others not described herein, may be used separately or in any combination together.
It will be understood that the term “effective vent opening area” as used herein may refer to the effective area through which the vent flow may pass in order to escape the vent assembly 6000 to ambient. This area may be affected by the number, size, shape and positioning of the vent outlets 6400 and also the degree to which the vent outlet(s) 6400 or the vent gap 6600 are occluded. For example, in the forms of the technology shown in
In forms of the technology where the membrane moves, a high level of occlusion (e.g. by the vent membrane 6200 flexing to a greater extent) reduces the number of vent outlet(s) or cap apertures 6330 that are open to the ambient, thus reducing the effective area of the vent. In some forms, the effective area of the vent may also be affected by the membrane apertures 6210. The number, shape, size and/or positioning of these apertures may be selected to achieve the desired pressure-flow characteristics.
The effective area of the vent may also be affected by the size of the vent gap 6600, i.e. the distance between the vent cap 6300 and the membrane 6200. Increasing this distance will generally increase the size of the effective area of the vent. The size of the vent gap 6600 may be selected to achieve the desired pressure-flow characteristics.
Characteristics of the membrane 6200 and/or the plurality of flaps 6700 may also be selected to achieve the desired pressure-flow characteristics. These characteristics of the membrane 6200 include but are not limited to: the material the membrane 6200 and/or the plurality of flaps 6700 is formed from, in particular the stiffness and/or hardness of the material; the thickness of the membrane 6200 and/or and the plurality of flaps 6700, in particular the thickness of the non-planar region 6220; and the shape of the membrane 6200 and/or and the plurality of flaps 6700, for instance the maximum height of the dome region in forms of the technology where the non-planar region 6220 is dome shaped and the curvature of the plurality of flaps 6700.
As has been explained, in certain forms of the technology, characteristics of the vent assembly 6300 may be selected in order to achieve a pressure-flow relationship in which the vent flow rate of the flow of exhaled air from the first volume through the vent assembly 6300 to ambient is substantially constant for a range of pressures inside the first volume or at least increases with increased pressure to a lesser extent than it would in a vent assembly with no moving parts. In some forms, the vent structure 3400 may be configured so that the pressure-flow relationship may remain between 8 to 13 L/min for pressures from 4 cmH2O to 25 cmH2O.
Vents in some forms of the present technology comprise a plunger 6140 moveably positioned with respect to a vent body 6130 to define a regulated vent flow passage 6132. The plunger 6140 may also be identified as a moveable portion. The plunger 6140 may be a moveable portion of the vent assembly 6000 that moves relative to another portion of the vent assembly 6000, for example the vent body 6130 or a portion thereof, for example to change a size or cross section of a passage through which gas can flow. In some examples, the plunger 6140 may move in translation, for example along a central axis of the vent assembly 6000 or a portion thereof. In some examples the plunger 6140 may move towards or into a vent body aperture 6138 in use. Some or all of the plunger 6140, for example a portion of the plunger 6140 that defines the regulated vent flow passage 6132, may be substantially rigid. The plunger 6140 may be connected to a flexible portion which is connected to a portion of the vent assembly 6000, the flexible portion allowing the plunger 6140 to move within the vent assembly 6000. As will be described, in some examples the flexible portion may be a membrane 6200.
As illustrated in
In use, changes in pressure of gas in the first volume cause changes in the position of the plunger 6140 relative to the vent body 6130. The pressure of gas in the first volume may act directly on the plunger 6140 or on another component attached to the plunger 6140, such as a membrane 6200, which will be described below. The plunger 6140 may begin to move when the pressure in the first volume becomes greater than the pressure acting on an opposing side of the plunger 6140, which may be ambient/atmospheric pressure or otherwise a lower pressure than the pressure of the first volume. The plunger 6140 may stop moving towards the vent body 6130 when biasing forces acting on the plunger 6140 (e.g. caused by elastic deformation of a membrane 6200 or other biasing means, to be described below), become sufficiently large to balance the force on the plunger 6140 caused by the pressure difference on opposing sides of the plunger 6140.
The vent assembly may be structured and arranged such that changes in pressure of gas in the first volume cause changes in a position of the plunger 6140 relative to the vent body 6130 to regulate the vent flow of gases through the regulated vent flow passage 6132 throughout a therapeutic pressure range. With increased pressure in the first volume, the plunger 6140 moves towards the vent body to reduce a cross sectional area within the regulated vent flow passage 6132, preventing a corresponding increase in volumetric vent flow rate or causing a lesser increase in volumetric vent flow rate than would otherwise be produced by a vent flow passage of fixed size. Regulation of vent flow rate and its advantages is discussed in detail above with reference to the vent assemblies shown in
The therapeutic pressure range throughout which a vent assembly 6000 regulates the vent flow of gases may be, in some examples, between 2 and 30 cmH2O or, in some examples, between 4 and 20 cmH2O.
As shown in
In the example shown in
In the example shown in
The vent assembly 6000 shown in
As shown in
In some examples of the present technology, the vent assembly 6000 may comprise one or more fixed size apertures 6135 defining one or more unregulated vent flow passages 6133 in addition to the regulated vent flow passages 6132. The provision of one or more unregulated vent flow passages 6133 in parallel with the regulated vent flow passages 6132 may advantageously help to tune the vent assembly 6000 to convey gases according to a desired pressure-flow relationship. In some examples the vent assembly 6000 may be tuned to allow a slowly rising flow rate with an increase in pressure. In further examples the vent assembly 6000 may be tuned to allow little or no increase in flow rate corresponding to an increase in pressure.
Furthermore, the fixed sizes apertures 6135 may ensure there are apertures through which gas can flow in the event the regulated gas flow passages 6132 inadvertently become closed or became stuck in a flow-restricting position. In the examples shown in
4.3.4.10.1 Plunger Vent with Diverging Flow Path
The vent body 6130 may comprise an upstream body portion 6133 and a downstream body portion 6134. The upstream body portion 6133 may define the vent body aperture 6138 and the downstream body portion 6134 may at least partially define the downstream portion 6162 of the regulated vent flow passage 6132. The upstream portion 6163 of the vent body 6130 may also partially define the downstream portion 6162 of the regulated vent flow passage 6132. In particular, the vent body 6130 comprises opposing divergent surfaces defining the downstream portion 6162 of the regulated vent flow passage 6132. The divergent surfaces may diverge in the downstream direction such that the cross-sectional area of the downstream portion 6162 of the regulated vent flow passage 6132 increases in the downstream direction. A vent flow passage with an enlarging cross-sectional area prior to release of the flow of gas may advantageously increase the vent flow diffusivity even without the use of a diffuser 6150. The absence of a diffuser 6150 may allow for the vent assembly 6000 to be multi-patient multi-use (MPMU) and may allow for the vent assembly 6000 to be shorter, since there is no space required for housing a diffuser 6150, while the shape of the downstream portion 6162 of the regulated vent flow passage 6132 still provides a diffusing effect. In other examples the vent assembly 6000 may also comprise a diffuser 6150 positioned downstream of the regulated vent flow passage 6132 to provide for additional diffusing.
In the example shown in
Furthermore, in the upstream portion 6161 of the regulated vent flow passage 6132 the gas flows partially radially inwardly and in the downstream portion 6162 the gas flows partially radially outwardly. This inward and then outward flow increases the length of the passage through which the gas flows in comparison to a straight passage from one end of the vent assembly 6000 to the other, which may advantageously further reduce velocity of the vent flow and/or noise. Furthermore, the directing the vent flow of gas to flow radially outward after leaving the vent outlets 6400 may advantageously cause further dispersal/diffusing of the vent flow, providing for a quiet vent and low flow velocities after venting of gas.
Further description of vent assemblies 6000 with diverging vent flow of gas is provided below in the Divergent Flow Vent section and is to be read together with the above. Likewise, the disclosure above with reference to
In the example shown in
In this example, the vent body 6130 encloses the upstream membrane 6201 and the downstream membrane 6202. The vent body 6130 differs from other examples described thus far in that it is formed in two lateral parts. The vent body 6130 comprises a first lateral side portion 6136 and a second lateral side portion 6137 opposing and connected to the first lateral side portion 6136. The first lateral side portion 6136 and the second lateral side portion 6137 may together define the vent body aperture 6138. The first lateral side portion 6136 and the second lateral side portion 6137 may also together define a circumferential outer surface of the vent body 6130, which may be a substantially cylindrical surface.
The first lateral side portion 6136 and the second lateral side portion 6137 may fit together with dowel pins and corresponding holes, as shown in
In some examples the first lateral side portion 6136 and the second lateral side portion 6137 may snap fit connect together.
As shown in
4.3.4.10.3 Plunger Vent with Spring
As an alternative to a membrane 6200, a vent assembly 6000 according to one form of the present technology may comprise a spring 6170.
The spring 6170 in this example comprises a coil spring 6170. The coil spring 6170 may be configured to be compressed in use. As shown in
In this example the spring 6170 is able to be compressed to allow the plunger 6140 to move towards the vent body 6130, and provides a restoring force to prevent the plunger 6140 from completely occluding the passage and to restore the plunger 6140 to a rest position when there is no longer pressure in the first volume.
As illustrated in
The downstream portion 6162 is shaped to have a cross-sectional area that enlarges in the downstream direction independent of movement or position of the plunger 6140. In this particular example, the bellows spring 6170 partially defines the downstream portion 6162 of the regulated vent flow passage 6132. Other features and advantages of a downstream portion 6162 of a regulated vent flow passage 6132 are describe elsewhere herein.
Also as shown in
In the example shown in
The vent assembly 6000 may comprise a first magnetic portion 6175 and a second magnetic portion 6175. One of the first magnetic portion 6175 and the second magnetic portion 6175 may comprise a magnet and the other of the first magnetic portion 6175 and the second magnetic portion 6175 may comprise a magnet or may comprise a ferromagnetic material. In the example shown in
With reference to
Referring again to
For avoidance of doubt, a first magnetic portion 6175 and a second magnetic portion 6175 may be provided in a vent assembly 6000 which has a moveable portion which moves to regulate a vent flow of gases, regardless of the form that the moveable portion takes (e.g. it may be a sleeve, membrane or another component). In such an example the moveable portion may be positioned with respect to a vent body 6130 to define a regulated vent flow passage 6132 for the vent flow of gases between the moveable portion and the vent body 6130. The moveable portion may be moveable with respect to the vent body 6130 and may be biased towards a rest position in which the regulated vent flow passage 6132 is open. A first magnetic portion 6175 may be supported within the vent assembly 6000 and a second magnetic portion 6175 may be provided to the moveable portion, a magnetic force acting between the first magnetic portion 6175 and the second magnetic portion 6175 biasing the moveable portion towards a rest position in which the regulated vent flow passage 6132 is open.
The use of magnetic attraction or repulsion to bias a moveable portion advantageously may help keep the moveable portion (e.g. plunger 6140 in the illustrated example) positioned correctly (e.g. centred within the vent assembly 6000). Furthermore, the force of magnetic attraction or repulsion is inversely proportional to the square of the separation of the magnetic portions, whereas the force of a spring or membrane may be directly proportional to displacement of the moveable portion. The use of magnetic forces may allow for the moveable portion to not move at low therapy pressures and instead only begin moving at higher therapy pressure. The vent assembly 6000 may only begin to move upon pressure in the first volume (e.g. a plenum chamber 3200) being reached. This may advantageously keep the regulated vent flow passage as open as possible at lower pressures to ensure ample gas washout when a patient uses only a low therapeutic pressure.
4.3.4.11 Washer Vent with Moveable Edge
Another form of the present technology is shown in
As shown in
In the example shown in
The vent flow being able to flow along a straight-line path from the regulated vent flow passage 6132 to and through one or more vent outlets 6400 unimpeded or impede only by one or more diffusers 6150 may advantageously provide for a quiet vent, since vent flow being caused to flow onto surfaces forcing a sudden change in direction of the vent flow at the surface may result in noise. A direct unimpeded path (or impeded only by a diffuser) to ambient may result in less noise than a path which is forced to change to direction. The straight-line path may be to one or more vent outlets 6400 from a “pinch point”, being a location at which the cross-sectional area of the vent flow passage is varied due to movement of a membrane 6200. This “pinch point” may be identified as a restriction in the regulated vent flow passage 6132 and may be location along the regulated vent flow passage 6132 at which the cross-sectional area of the flow passage is at a minimum. The vent flow of gas (or at least some of it) may be able to travel in a straight line from location having the smallest cross-sectional area to a vent outlet 4600 unimpeded or impeded only by a diffuser 6150.
In some examples, and as shown in
In the example shown in
As shown in particular in
The membrane may also comprise a bead formed at the moveable edge 6205. The bead may advantageously have a stabilising effect on the moveable edge 6205, for example by stiffening it. Additionally, or alternatively, as exemplified in
The vent body 6130 in the examples shown in
In many examples described herein the vent assembly 6000 comprises a plurality of vent outlets 6400, some of which may open radially outwards as shown in
As described above, the vent assembly 6000 may comprise a diffuser 6150. Each of the vent assemblies 6000 shown in
It is to be understood that the straight-line path may in practice be a plurality of straight line paths around a circumference of the vent assembly 6000 due to multiple vent outlets 6400. In some examples the straight-line path may in practice be continuous radially outward flow which can be described as forming straight-line paths due to being a straight line when depicted in cross section.
The membrane retainer portion 6180 in this example forms the membrane-adjacent portion 6206 of the vent body 6130. In particular, the membrane-adjacent portion 6206 may be formed by an inner peripheral edge of the membrane retainer portion 6180. In this example, the membrane retainer portion 6180 comprises a cylindrical portion forming the periphery of the membrane retainer portion 6180 (and also forming the periphery of the vent body 6130) and, as shown in
In the example shown in
As shown in
Another feature of the vent assembly 6000 shown in
4.3.4.12 Washer Vent Having Membrane with Apertures
In this example the vent assembly 6000 comprises an annular membrane 6200. The annular membrane 6200 may be mounted within the vent assembly 6000 and may comprise an inner edge 6207 and an outer edge 6208. The membrane 6200 may further comprise at least one membrane aperture 6210 formed in the membrane 6200 between the inner edge 6207 and the outer edge 6208. As shown in
In the example shown in
The one or more vent outlets 6400 may comprise at least one annular vent outlet 6400. As shown in
The membrane 6200 may comprise a plurality of membrane apertures 6200 spaced along a circumference of the membrane 6200. As shown in
In some alternative examples, the membrane apertures 6210 may circular, ovals, or any other shapes. For example, each membrane aperture 6210 may in some examples be a circular hole.
In some examples, in addition to one or more membrane apertures 6210 which move with respect to a membrane-adjacent portion 6206, one of the inner edge 6208 and the outer edge 6207 may be a moveable edge 6205 of the membrane 6200. The vent assembly 6000 in
The moveable edge 6205 and second membrane-adjacent portion 6206b may function in the same or a similar manner to the moveable edge 6205 and membrane-adjacent portion 6206 in other examples of vent assemblies 6000 disclosed herein having annular membranes 6200 without membrane apertures 6210, such as shown in
At least below a predetermined pressure, the vent flow of gas may pass through the first regulated vent flow passage 6132a and the second regulated vent flow passage 6132b in parallel. However, in some examples upon pressure in the first volume exceeding the predetermined pressure, the second regulated vent flow passage 6132b closes. This is because the moveable edge 6205 may contact and seal against the second-membrane adjacent portion 6206b of the vent body 6130 and prevent flow. This two-stage regulation of vent flow may advantageously allow for ample vent flow rate at lower therapeutic pressures, ensuring the vent assembly 6000 is at least sufficiently open to maintain sufficient gas washout even at low therapeutic pressures, but may also allow for complete closing of the first regulated vent flow passage 6132a at higher therapeutic pressures when only a single (second) regulated vent flow passage 6132b is required.
Referring to
In a variation of the example shown in
As mentioned above, a vent assembly 6000 with forming a regulated vent flow passage 6132 may also comprise one or more fixed size apertures defining one or more unregulated vent flow passages 6213. As shown in
With reference to
In the
The downstream portion 6192 of the vent flow passage 6131 is defined by opposing non-parallel surfaces 6195. Each of the non-parallel surfaces 6195 in the illustrated example extends radially outwardly in the downstream direction, which helps to discharge the vent flow of gas outwardly from the vent assembly 6000, encouraging further diffusivity. In this example each of the non-parallel surfaces 6195 is frustoconical.
In the example shown in
In one form the patient interface 3000 includes at least one decoupling structure, for example, a swivel or a ball and socket. In some forms, the decoupling structure may be part of an elbow structure or connection member located between, and configured to fluidly connect, the plenum chamber 3200 and the air circuit 4170.
Connection port 3600 allows for connection to the air circuit 4170.
In one form, the patient interface 3000 includes a forehead support 3700.
In one form, the patient interface 3000 includes an anti-asphyxia valve (AAV). In other forms, the AAV may be located in an elbow structure or connection member located between the plenum chamber 3200 and the air circuit 4170. Alternatively, the AAV may be located in a part of the conduit headgear, for example tubes 3350. An AAV may alternatively be referred to as a non-rebreathing valve (NRV).
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.
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.
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, such as with processor control instructions to be executed by one or more processor(s), 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 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 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. oxygen enriched air.
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’.
In the example of patient respiration, a flow rate may be nominally positive for the inspiratory portion of a breathing cycle of a patient, and hence negative for the expiratory portion of the breathing cycle of a patient. Device flow rate, Qd, is the flow rate of air leaving the RPT device. Total flow rate, Qt, is the flow rate of air and any supplementary gas reaching the patient interface via the air circuit. Vent flow rate, Qv, is the flow rate of air leaving a vent to allow washout of exhaled gases. Leak flow rate, Ql, is the flow rate of leak from a patient interface system or elsewhere. Respiratory flow rate, Qr, is the flow rate of air that is received into the patient's respiratory system.
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.
Oxygen enriched air: Air with a concentration of oxygen greater than that of atmospheric air (21%), for example at least about 50% oxygen, at least about 60% oxygen, at least about 70% oxygen, at least about 80% oxygen, at least about 90% oxygen, at least about 95% oxygen, at least about 98% oxygen, or at least about 99% oxygen. “Oxygen enriched air” is sometimes shortened to “oxygen”.
Medical Oxygen: Medical oxygen is defined as oxygen enriched air with an oxygen concentration of 80% or greater.
Patient: A person, whether or not they are suffering from a respiratory condition.
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: 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.
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.
Stiffener: A stiffener will be taken to mean a structural component designed to increase the bending resistance of another component in at least one direction.
Strut: A strut will be taken to be a structural component designed to increase the compression resistance of another component in at least one direction.
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.
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 |
|---|---|---|---|
| 2021903140 | Oct 2021 | AU | national |
| 2022901050 | Apr 2022 | AU | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/AU2022/051170 | 9/30/2022 | WO |
