Heat and moisture exchanger

Abstract

A heat and moisture exchanger (HMX) is disclosed. The HMX comprises a folded HMX material, wherein the HMX material comprises a plurality of parallel first fold lines and a plurality of second fold lines. The second fold lines are zig-zag lines which intersect each of the first fold lines, wherein the second fold lines change direction at each intersection with the first fold lines. The first and second fold lines define a plurality of tessellating parallelogram shaped panels. The first fold lines alternate between mountain folds and valley folds at each intersection with the second fold lines, wherein the second fold lines comprise alternate mountain folds and valley folds.

Description

HEAT AND MOISTURE EXCHANGER1 BACKGROUND OF THE TECHNOLOGY1.1 FIELD OF THE TECHNOLOGY

[0001] The present technology relates to one or more of the screening, diagnosis, monitoring, treatment, prevention and amelioration of respiratory-related disorders. The present technology also relates to medical devices or apparatus, and their use.1.2 DESCRIPTION OF THE RELATED ART1.2.1 Human Respiratory System and its Disorders

[0002] The respiratory system of the body facilitates gas exchange. The nose and mouth form the entrance to the airways of a patient.

[0003] 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.

[0004] A range of respiratory disorders exist. Certain disorders may be characterised by particular events, e.g. apneas, hypopneas, and hyperpneas.

[0005] Examples of respiratory disorders include Obstructive Sleep Apnea (OSA), Cheyne-Stokes Respiration (CSR), respiratory insufficiency, Obesity Hypoventilation Syndrome (OHS), Chronic Obstructive Pulmonary Disease (COPD), Neuromuscular Disease (NMD) and Chest wall disorders.

[0006] Obstructive Sleep Apnea (OSA), a form of Sleep Disordered Breathing (SDB), is characterised by events including occlusion or obstruction of the upper air passage during sleep. It results from a combination of an abnormally small upper airway and the normal loss of muscle tone in the region of the tongue, soft palate and posterior oropharyngeal wall during sleep. The condition causes the affected patient to stop breathing for periods typically of 30 to 120 seconds in duration, sometimes 200 to 300 times per night. It often causes excessive daytime somnolence, and it mayA2578192 12.0 1cause cardiovascular disease and brain damage. The syndrome is a common disorder, particularly in middle aged overweight males, although a person affected may have no awareness of the problem, e.g. see US Patent No. 4,944,310 (Sullivan).

[0007] Cheyne-Stokes Respiration (CSR) is another form of sleep disordered breathing. CSR is a disorder of a patient's respiratory controller in which there are rhythmic alternating periods of waxing and waning ventilation known as CSR cycles. CSR is characterised by repetitive de-oxygenation and re-oxygenation of the arterial blood. It is possible that CSR is harmful because of the repetitive hypoxia. In some patients CSR is associated with repetitive arousal from sleep, which causes severe sleep disruption, increased sympathetic activity, and increased afterload, e.g. see US Patent No. 6,532,959 (Berthon- Jones).

[0008] Respiratory failure is an umbrella term for respiratory disorders in which the lungs are unable to inspire sufficient oxygen or exhale sufficient CO2 to meet the patient’s needs. Respiratory failure may encompass some or all of the following disorders.

[0009] A patient with respiratory insufficiency (a form of respiratory failure) may experience abnormal shortness of breath on exercise.

[0010] Obesity Hypoventilation Syndrome (OHS) is defined as the combination of severe obesity and awake chronic hypercapnia, in the absence of other known causes for hypoventilation. Symptoms include dyspnea, morning headache and excessive daytime sleepiness.

[0011] Chronic Obstructive Pulmonary Disease (COPD) encompasses any of a group of lower airway diseases that have certain characteristics in common. These include increased resistance to air movement, extended expiratory phase of respiration, and loss of the normal elasticity of the lung. Examples of COPD are emphysema and chronic bronchitis. COPD is caused by chronic tobacco smoking (primary risk factor), occupational exposures, air pollution and genetic factors. Symptoms include: dyspnea on exertion, chronic cough and sputum production.

[0012] Neuromuscular Disease (NMD) is a broad term that encompasses many diseases and ailments that impair the functioning of the muscles either directly via intrinsic muscle pathology, or indirectly via nerve pathology. Some NMD patients are characterised by progressive muscular impairment leading to loss of ambulation, being wheelchair-bound, swallowing difficulties, respiratory muscle weakness and, eventually, death from respiratory failure. Neuromuscular disorders can be dividedA2578192 12.0 2into rapidly progressive and slowly progressive: (i) Rapidly progressive disorders: Characterised by muscle impairment that worsens over months and results in death within a few years (e.g. Amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers); (ii) Variable or slowly progressive disorders: Characterised by muscle impairment that worsens over years and only mildly reduces life expectancy (e.g. Limb girdle, Facioscapulohumeral and Myotonic muscular dystrophy). Symptoms of respiratory failure in NMD include: increasing generalised weakness, dysphagia, dyspnea on exertion and at rest, fatigue, sleepiness, morning headache, and difficulties with concentration and mood changes.

[0013] Chest wall disorders are a group of thoracic deformities that result in inefficient coupling between the respiratory muscles and the thoracic cage. The disorders are usually characterised by a restrictive defect and share the potential of long term hypercapnic respiratory failure. Scoliosis and / or kyphoscoliosis may cause severe respiratory failure. Symptoms of respiratory failure include: dyspnea on exertion, peripheral oedema, orthopnea, repeated chest infections, morning headaches, fatigue, poor sleep quality and loss of appetite.

[0014] A range of therapies have been used to treat or ameliorate such conditions. Furthermore, otherwise healthy individuals may take advantage of such therapies to prevent respiratory disorders from arising. However, these have a number of shortcomings.1.2.2 Therapies

[0015] Various respiratory therapies, such as Continuous Positive Airway Pressure (CPAP) therapy, Non-invasive ventilation (NIV), Invasive ventilation (IV), and High Flow Therapy (HFT) have been used to treat one or more of the above respiratory disorders.1.2.2.1 Respiratory pressure therapies

[0016] 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).

[0017] Continuous Positive Airway Pressure (CPAP) therapy has been used to treat Obstructive Sleep Apnea (OSA). The mechanism of action is that continuous positive airway pressure acts as a pneumatic splint and may prevent upper airwayA2578192 12.0 3occlusion, such as by pushing the soft palate and tongue forward and away from the posterior oropharyngeal wall. Treatment of OSA by CPAP therapy may be voluntary, and hence patients may elect not to comply with therapy if they find devices used to provide such therapy one or more of: uncomfortable, difficult to use, expensive and aesthetically unappealing.

[0018] Non-invasive ventilation (NIV) provides ventilatory support to a patient through the upper airways to assist the patient breathing and / or maintain adequate oxygen levels in the body by doing some or all of the work of breathing. The ventilatory support is provided via a non-invasive patient interface. NIV has been used to treat CSR and respiratory failure, in forms such as OHS, COPD, NMD and Chest Wall disorders. In some forms, the comfort and effectiveness of these therapies may be improved.

[0019] Invasive ventilation (IV) provides ventilatory support to patients that are no longer able to effectively breathe themselves and may be provided using a tracheostomy tube or endotracheal tube. In some forms, the comfort and effectiveness of these therapies may be improved.1.2.2.2 Flow therapies

[0020] Not all respiratory therapies aim to deliver a prescribed therapeutic pressure. Some respiratory therapies aim to deliver a prescribed respiratory volume, by delivering an inspiratory flow rate profile over a targeted duration, possibly superimposed on a positive baseline pressure. In other cases, the interface to the patient’s airways is ‘open’ (unsealed) and the respiratory therapy may only supplement the patient’s own spontaneous breathing with a flow of conditioned or enriched gas. In one example, High Flow therapy (HFT) is the provision of a continuous, heated, humidified flow of air to an entrance to the airway through an unsealed or open patient interface at a “treatment flow rate” that may be held approximately constant throughout the respiratory cycle. The treatment flow rate is nominally set to exceed the patient’s peak inspiratory flow rate. HFT has been used to treat OSA, CSR, respiratory failure, COPD, and other respiratory disorders. One mechanism of action is that the high flow rate of air at the airway entrance improves ventilation efficiency by flushing, or washing out, expired CO2 from the patient’s anatomical deadspace. Hence, HFT is thus sometimes referred to as a deadspace therapy (DST). Other benefits may include the elevated warmth and humidification (possibly of benefit in secretion management) and the potential for modest elevationA2578192 12.0 4of airway pressures. As an alternative to constant flow rate, the treatment flow rate may follow a profile that varies over the respiratory cycle.

[0021] Another form of flow therapy is long-term oxygen therapy (LTOT) or supplemental oxygen therapy. Doctors may prescribe a continuous flow of oxygen enriched air at a specified oxygen concentration (from 21%, the oxygen fraction in ambient air, to 100%) at a specified flow rate (e.g., 1 litre per minute (LPM), 2 LPM, 3 LPM, etc.) to be delivered to the patient’s airway.1.2.2.3 Supplementary oxygen

[0022] For certain patients, oxygen therapy may be combined with a respiratory pressure therapy or HFT by adding supplementary oxygen to the pressurised flow of air. When oxygen is added to respiratory pressure therapy, this is referred to as RPT with supplementary oxygen. When oxygen is added to HFT, the resulting therapy is referred to as HFT with supplementary oxygen.1.2.3 Respiratory Therapy Systems

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

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

[0025] A patient interface may be used to interface respiratory equipment to its wearer, for example by providing a flow of air to an entrance to the airways. The flow of air may be provided via a mask to the nose and / or mouth, a tube to the mouth or a tracheostomy tube to the trachea of a patient. Depending upon the therapy to be applied, the patient interface may form a seal, e.g., with a region of the patient's face, to facilitate the delivery of gas at a pressure at sufficient variance with ambient pressure to effect therapy, e.g., at a positive pressure of about 10 cmH20 relative to ambient pressure. For other forms of therapy, such as the delivery of oxygen, the patient interface may not include a seal sufficient to facilitate delivery to the airways of a supply of gas at a positive pressure of about 10 cmH20. For flow therapies such as nasal HFT, the patient interface is configured to insufflate the nares but specifically to avoid a complete seal. One example of such a patient interface is a nasal cannula.A2578192 12.0 51.2.3.2 Respiratory Pressure Therapy (RPT) Device

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

[0027] The designer of a device may be presented with an infinite number of choices to make. Design criteria often conflict, meaning that certain design choices are far from routine or inevitable. Furthermore, the comfort and efficacy of certain aspects may be highly sensitive to small, subtle changes in one or more parameters.1.2.3.3 Air circuit

[0028] An air circuit is a conduit or a tube constructed and arranged to allow, in use, a flow of air to travel between two components of a respiratory therapy system such as the RPT device and the patient interface. In some cases, there may be separate limbs of the air circuit for inhalation and exhalation. In other cases, a single limb air circuit is used for both inhalation and exhalation.1.2.3.4 Humidifier

[0029] Delivery of a flow of air without humidification may cause drying of airways. The use of a humidifier with an RPT device and the patient interface produces humidified gas that minimizes drying of the nasal mucosa and increases patient airway comfort. In addition, in cooler climates, warm air applied generally to the face area in and about the patient interface is more comfortable than cold air.1.2.3.5 Data Management

[0030] There may be clinical reasons to obtain data to determine whether the patient prescribed with respiratory therapy has been “compliant”, e.g. that the patient has used their RPT device according to one or more “compliance rules”. One example of a compliance rule for CPAP therapy is that a patient, in order to be deemed compliant, is required to use the RPT device for at least four hours a night for at least 21 of 30 consecutive days. In order to determine a patient's compliance, a provider of the RPT device, such as a health care provider, may manually obtain data describing the patient's therapy using the RPT device, calculate the usage over a predeterminedA2578192 12.0 6time period, and compare with the compliance rule. Once the health care provider has determined that the patient has used their RPT device according to the compliance rule, the health care provider may notify a third party that the patient is compliant.

[0031] There may be other aspects of a patient’s therapy that would benefit from communication of therapy data to a third party or external system.

[0032] Existing processes to communicate and manage such data can be one or more of costly, time-consuming, and error-prone.1.2.3.6 Vent technologies

[0033] 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.1.2.4 Heat and Moisture Exchanger (HMX)

[0034] HMXs (sometimes also called HMEs) may be utilized in RPT therapy, such as in PAP therapy, to partially recover heat and moisture present in exhaled gas from a patient’s airways. This heat and moisture can be retained and recycled to the patient in a passive manner as a flow of breathable gas passes through the HMX prior to inspiration. Thus, the use of HMXs can provide the needed moisture and humidity (generally recognized as >10mg / l) to most patients during PAP therapy to minimize any detrimental effects associated with PAP therapy with non-humidified ambient air whilst avoiding the need for a heated humidifier system. The use of a HMX rather than a heated humidifier may also lower the possibility of occlusion caused by condensation in air delivery tubes.

[0035] The use of a HMX in PAP therapy can avoid the need for additional power required with heated humidifiers and may reduce the need for extra associated components. This may reduce the manufacturing costs and also reduce the overall size of the CPAP therapy unit.

[0036] Heat and moisture exchangers are generally made up of an exchanging material, such as foam, paper, or a substance capable of acting as a condensation and absorption surface. The material may carry hygroscopic salts to improve the waterretaining capacity. Suitable salts include calcium chloride.

[0037] A problem common with the use of HMXs in CPAP therapy relates to the ability of the HMX to provide sufficient heat and moisture while also minimizingA2578192 12.0 7flow impedance and maintaining comfortable and safe levels of CO2 washout, i.e. removing CO2 from the patient interface. Flow impedance may affect patient breathing effort (work of breathing) and also impacts event (apnoea, hypopnoea, snore) detection algorithms, so in many cases it is sought to be minimized. Furthermore, consideration should also be given to heat and moisture loss from venting to ensure that the HMX is functioning to counteract this loss.

[0038] It can be advantageous to design HMXs for use in RPT therapy which provide adequate patient humidification, while minimising issues with flow impedance and / or CO2 washout. For example, placing the HMX unit within the elbow, around the exhaust vent or on the flow generator side of the therapy system may result in issues with impedance, and / or CO2 washout with negligible patient humidification (hygroscopic) benefit. In this configuration the vent flow may be the dominant flow through the HME, the vent flow being the flow from the patient or the flow generator that flows through the HMX and directly out through the vent. Moreover, some current designs of HMXs do not allow for sufficient moisture exchange during patient exhalation to provide sufficient humidification levels to the patient. Thus, there is a need to provide superior configurations and designs for HMX use in RPT therapy, such as PAP therapy, to achieve desired patient humidification whilst having acceptable impedance on the flow of therapy and CO2 washout.

[0039] Many HMXs are made from paper since suitable biocompatible paper is available. The paper may be folded or fluted to increase the surface area which is in contact with the gasses exhaled by the patient.

[0040] One impediment to adequate CO2 washout and / or low flow impedance in an oronasal (full face) mask with a paper HMX may be that the direction of flow of gasses exhaled from the patient’s nares may be different to the direction of flow of gasses exhaled from the mouth. If an HMX is formed with a plurality of substantially parallel channels for the flow, then at least one of the nasal and the oral flows will impinge on the HMX at an angle to the channels, thereby increasing impedance to the flow and potentially increasing CO2 rebreathing rates. Alternatively, the openings to the channels may not be orthogonal to both flows which may also increase impedance.A2578192 12.0 81.2.5 Screening, Diagnosis, and Monitoring Systems

[0041] Polysomnography (PSG) is a conventional system for diagnosis and monitoring of cardio-pulmonary disorders, and typically involves expert clinical staff to apply the system. PSG typically involves the placement of 15 to 20 contact sensors on a patient in order to record various bodily signals such as electroencephalography (EEG), electrocardiography (ECG), electrooculograpy (EOG), electromyography (EMG), etc. PSG for sleep disordered breathing has involved two nights of observation of a patient in a clinic, one night of pure diagnosis and a second night of titration of treatment parameters by a clinician. PSG is therefore expensive and inconvenient. In particular, it is unsuitable for home screening / diagnosis / monitoring of sleep disordered breathing.

[0042] Screening and diagnosis generally describe the identification of a condition from its signs and symptoms. Screening typically gives a true / false result indicating whether or not a patient’s SDB is severe enough to warrant further investigation, while diagnosis may result in clinically actionable information. Screening and diagnosis tend to be one-off processes, whereas monitoring the progress of a condition can continue indefinitely. Some screening / diagnosis systems are suitable only for screening / diagnosis, whereas some may also be used for monitoring.

[0043] Clinical experts may be able to screen, diagnose, or monitor patients adequately based on visual observation of PSG signals. However, there are circumstances where a clinical expert may not be available, or a clinical expert may not be affordable. Different clinical experts may disagree on a patient’s condition. In addition, a given clinical expert may apply a different standard at different times.2 BRIEF SUMMARY OF THE TECHNOLOGY

[0044] 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.

[0045] A first aspect of the present technology relates to apparatus used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respiratory disorder.A2578192 12.0 9

[0046] Another aspect of the present technology relates to methods used in the screening, diagnosis, monitoring, amelioration, treatment or prevention of a respiratory disorder.

[0047] An aspect of certain forms of the present technology is to provide methods and / or apparatus that improve the compliance of patients with respiratory therapy.

[0048] One form of the present technology comprises a positioning and stabilising structure configured to provide a force to hold the seal-forming structure in a therapeutically effective position on the patient’s head. The positioning and stabilising structure includes at least one strap.

[0049] One form of the present technology comprises a patient interface comprising a plenum chamber, a seal-forming structure, and a positioning and stabilising structure.

[0050] One form of the present technology comprises patient interface comprising a plenum chamber pressurisable to a therapeutic pressure of at least 4 cmH20 above ambient air pressure. The plenum chamber includes at least one plenum chamber inlet port sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient. The patient interface also comprises a seal-forming structure that is constructed and arranged to form a seal with a region of the patient’s face surrounding an entrance to the patient’s airways. The seal-forming structure has a hole therein such that the flow of air at said therapeutic pressure is delivered to at least an entrance to the patient’s nares. The seal-forming structure is constructed and arranged to maintain said therapeutic pressure in the plenum chamber throughout the patient’s respiratory cycle in use. The patient interface also comprises a positioning and stabilising structure to provide a force to hold the seal-forming structure in a therapeutically effective position on the patient’s head.

[0051] Another aspect of one form of the present technology is a series of modular elements that may be interconnected in order to form different styles of patient interfaces.

[0052] In one form, there are at least two versions or styles of each modular element. The versions or styles may be interchangeably used with one another in order to form different modular assemblies.

[0053] One form of the present technology comprises a heat and moisture exchanger (HMX) comprising a folded HMX material, wherein the HMX material comprises a plurality of parallel first fold lines and a plurality of second fold lines, theA2578192 12.0 10second fold lines being zig-zag lines which intersect each of the first fold lines, wherein the second fold lines change direction at each intersection with the first fold lines, the first and second fold lines defining a plurality of tessellating parallelogram shaped panels, wherein the first fold lines alternate between mountain folds and valley folds at each intersection with the second fold lines, and wherein the second fold lines comprise alternate mountain folds and valley folds.

[0054] In examples: a) the HMX material comprises a plurality of unit cells, each unit cell having a first pair of adjacent panels and a second pair of adjacent panels, wherein a boundary between the panels of each pair of panels is defined by one of the first fold lines, wherein the first fold line between the first pair of panels is arranged as a valley fold and the first fold line between the second pair of panels is arranged as a mountain fold, and wherein a boundary between the first pair of panels and the second pair of adjacent panels is defined by one of the second fold lines which is arranged as a mountain fold, and wherein the HMX material is arranged such that the angle between the first pair of panels is less than 45 degrees; b) the angle between the first pair of panels is less than 35 degrees; c) an aperture is provided at each end of each mountain fold or each valley fold; and / or d) additional apertures are provided mid way along a plurality of the mountain folds and / or a plurality of the valley folds.

[0055] Another form of the present technology comprise a heat and moisture exchanger (HMX) comprising an HMX material folded in a Miura-ori configuration.

[0056] In examples: a) the HMX material comprises a plurality of unit cells, each unit cell having a first pair of adjacent panels and a second pair of adjacent panels, wherein aA2578192 12.0 11boundary between the panels of each pair of panels is defined by a first fold line, wherein the first fold line between the first pair of panels is arranged as a valley fold and the first fold line between the second pair of panels is arranged as a mountain fold, and wherein a boundary between the first pair of panels and the second pair of adjacent panels is defined by a second fold line which is arranged as a mountain fold, and wherein the HMX material is arranged such that the angle between the first pair of panels is less than 45 degrees; b) the angle between the first pair of panels is less than 35 degrees; c) an aperture is provided at each end of each mountain fold or each valley fold; and / or d) additional apertures are provided mid way along a plurality of the mountain folds and / or a plurality of the valley folds.

[0057] Another form of the present technology comprises a heat and moisture exchanger (HMX) comprising an HMX material folded in a Miura-ori configuration comprising a plurality of pairs of unit cells, each unit cell comprising: a first pair of adjacent panels and a second pair of adjacent panels, wherein a boundary between each panel in each pair of panels is defined by a first fold line, wherein the first fold line between the first pair of panels is arranged as a valley fold and the first fold line between the second pair of panels is arranged as a mountain fold, wherein a boundary between the first pair of panels and the second pair of panels is defined by a second fold line which is arranged as a mountain fold, wherein the unit cells in each pair of unit cells are connected together such that they share a common first fold line, wherein the lateral ends of the second fold lines of each unit cell in each pair of unit cells lie on a common surface, andA2578192 12.0 12wherein the HMX material is arranged such that the surface of one of the pairs of unit cells is non-planar with the surface of another of the pairs of unit cells.

[0058] Another aspect of one form of the present technology is a patient interface that is moulded or otherwise constructed with a perimeter shape which is complementary to that of an intended wearer.

[0059] An aspect of one form of the present technology is a method of manufacturing apparatus.

[0060] Another aspect of one form of the present technology is a method of assembling a modular system comprising selecting a positioning and stabilising structure, and connecting the positioning and stabilising structure to either a first cushion or a second cushion.

[0061] 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.

[0062] An aspect of one form of the present technology is a portable RPT device that may be carried by a person, e.g., around the home of the person.

[0063] An aspect of one form of the present technology is a patient interface that may be washed in a home of a patient, e.g., in soapy water, without requiring specialised cleaning equipment. An aspect of one form of the present technology is a humidifier tank that may be washed in a home of a patient, e.g., in soapy water, without requiring specialised cleaning equipment.

[0064] The methods, systems, devices and apparatus described may be implemented so as to improve the functionality of a processor, such as a processor of a specific purpose computer, respiratory monitor and / or a respiratory therapy apparatus. Moreover, the described methods, systems, devices and apparatus can provide improvements in the technological field of automated management, monitoring and / or treatment of respiratory conditions, including, for example, sleep disordered breathing.

[0065] 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.A2578192 12.0 13

[0066] Other features of the technology will be apparent from consideration of the information contained in the following detailed description, abstract, drawings and claims.3 BRIEF DESCRIPTION OF THE DRAWINGS

[0067] The present technology is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which like reference numerals refer to similar elements including:3.1 RESPIRATORY THERAPY SYSTEMS

[0068] Fig. 1 A shows a system including a patient 1000 wearing a patient interface 3000, in the form of nasal pillows, receiving a supply of air at positive pressure from an RPT device 4000. Air from the RPT device 4000 is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000. A bed partner 1100 is also shown. The patient is sleeping in a supine sleeping position.

[0069] Fig. IB shows a system including a patient 1000 wearing a patient interface 3000, in the form of a nasal mask, receiving a supply of air at positive pressure from an RPT device 4000. Air from the RPT device is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000.

[0070] Fig. 1C shows a system including a patient 1000 wearing a patient interface 3000, in the form of a full -face mask, receiving a supply of air at positive pressure from an RPT device 4000. Air from the RPT device is humidified in a humidifier 5000, and passes along an air circuit 4170 to the patient 1000. The patient is sleeping in a side sleeping position.3.2 RESPIRATORY SYSTEM AND FACIAL ANATOMY

[0071] Fig. 2 A shows an overview of a human respiratory system including the nasal and oral cavities, the larynx, vocal folds, oesophagus, trachea, bronchus, lung, alveolar sacs, heart and diaphragm.3.3 PATIENT INTERFACE

[0072] Fig. 3 A shows a patient interface in the form of a nasal mask in accordance with one form of the present technology.

[0073] Fig. 3B shows a schematic of a cross-section through a structure at a point. An outward normal at the point is indicated. The curvature at the point has a positive sign, and a relatively large magnitude when compared to the magnitude of the curvature shown in Fig. 3C.A2578192 12.0 14

[0074] Fig. 3C shows a schematic of a cross-section through a structure at a point. An outward normal at the point is indicated. The curvature at the point has a positive sign, and a relatively small magnitude when compared to the magnitude of the curvature shown in Fig. 3B.

[0075] Fig. 3D shows a schematic of a cross-section through a structure at a point. An outward normal at the point is indicated. The curvature at the point has a value of zero.

[0076] Fig. 3E shows a schematic of a cross-section through a structure at a point. An outward normal at the point is indicated. The curvature at the point has a negative sign, and a relatively small magnitude when compared to the magnitude of the curvature shown in Fig. 3F.

[0077] Fig. 3F shows a schematic of a cross-section through a structure at a point. An outward normal at the point is indicated. The curvature at the point has a negative sign, and a relatively large magnitude when compared to the magnitude of the curvature shown in Fig. 3E.

[0078] Fig. 3G shows a cushion for a mask that includes two pillows. An exterior surface of the cushion is indicated. An edge of the surface is indicated. Dome and saddle regions are indicated.

[0079] Fig. 3H shows a cushion for a mask. An exterior surface of the cushion is indicated. An edge of the surface is indicated. A path on the surface between points A and B is indicated. A straight line distance between A and B is indicated. Two saddle regions and a dome region are indicated.

[0080] Fig. 31 shows the surface of a structure, with a one dimensional hole in the surface. The illustrated plane curve forms the boundary of a one dimensional hole.

[0081] Fig. 3J shows a cross-section through the structure of Fig.31. The illustrated surface bounds a two dimensional hole in the structure of Fig. 31.

[0082] Fig. 3K shows a perspective view of the structure of Fig. 31, including the two dimensional hole and the one dimensional hole. Also shown is the surface that bounds a two dimensional hole in the structure of Fig. 31.

[0083] Fig. 3L shows a mask having an inflatable bladder as a cushion.

[0084] Fig. 3M shows a cross-section through the mask of Fig. 3L, and shows the interior surface of the bladder. The interior surface bounds the two dimensional hole in the mask.A2578192 12.0 15

[0085] Fig. 3N shows a further cross-section through the mask of Fig. 3L. The interior surface is also indicated.

[0086] Fig. 30 illustrates a left-hand rule.

[0087] Fig. 3P illustrates a right-hand rule.

[0088] Fig. 3Q shows a left ear, including the left ear helix.

[0089] Fig. 3R shows a right ear, including the right ear helix.

[0090] Fig. 3S shows a right-hand helix.

[0091] Fig. 3T shows a view of a mask, including the sign of the torsion of the space curve defined by the edge of the sealing membrane in different regions of the mask.3.4 RPT DEVICE

[0092] Fig. 4A shows an RPT device in accordance with one form of the present technology.

[0093] Fig. 4B is a schematic diagram of the pneumatic path of an RPT device in accordance with one form of the present technology. The directions of upstream and downstream are indicated with reference to the blower and the patient interface. The blower is defined to be upstream of the patient interface and the patient interface is defined to be downstream of the blower, regardless of the actual flow direction at any particular moment. Items which are located within the pneumatic path between the blower and the patient interface are downstream of the blower and upstream of the patient interface.3.5 HUMIDIFIER

[0094] Fig. 5A shows an isometric view of a humidifier in accordance with one form of the present technology.

[0095] Fig. 5B shows an isometric view of a humidifier in accordance with one form of the present technology, showing a humidifier reservoir 5110 removed from the humidifier reservoir dock 5130.3.6 BREATHING WAVEFORMS

[0096] Fig. 6 shows a model typical breath waveform of a person while sleeping.3.7 HEAT AND MOISTURE EXCHANGERS

[0097] Fig. 7 shows a plan view of HMX material folded in a Miura-ori configuration according to one form of the technology.

[0098] Fig. 8 is a diagram showing Miura-ori configuration fold lines.A2578192 12.0 16

[0099] Fig. 9A shows a perspective diagrammatic view from above of a piece of HMX material in a Miura-ori configuration, partially folded.

[0100] Fig. 9B shows a diagrammatic side view of the HMX material shown in Fig. 9A.

[0101] Fig. 9C shows a diagrammatic perspective view of a single cell of the HMX material of Fig. 9 A.

[0102] Fig. 10 shows a piece of perforated HMX material which has been folded in a Miura-ori configuration.

[0103] Fig. 11 shows another piece of perforated HMX material which has been folded in a Miura-ori configuration.

[0104] Fig. 12A shows a view of a non-patient facing side of an HMX according to one form of the technology.

[0105] Fig. 12B shows a view of a patient facing side of the HMX of Fig. 12A.

[0106] Fig. 12C shows a perspective view of the HMX of Fig. 12A in a deformed configuration.

[0107] Fig. 13 A shows a view from behind of an anterior portion of one form of patient interface with the HMX of Fig. 12A mounted to it.

[0108] Fig. 13B shows a view from in front of the patient interface and HMX of Fig. 13A.

[0109] Fig. 14 shows an end view of an HMX according to one form of the technology.

[0110] Fig. 15A shows an end view of an HMX according to one form of the technology.

[0111] Fig. 15B shows an opposite end view of the HMX of Fig. 15 A.4 DETAILED DESCRIPTION OF EXAMPLES OF THETECHNOLOGY

[0112] 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.

[0113] The following description is provided in relation to various examples which may share one or more common characteristics and / or features. It is to beA2578192 12.0 17understood 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.4.1 THERAPY

[0114] 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.

[0115] 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.

[0116] In certain examples of the present technology, mouth breathing is limited, restricted or prevented.4.2 RESPIRATORY THERAPY SYSTEMS

[0117] 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 3000.4.3 PATIENT INTERFACE

[0118] A non-invasive patient interface 3000, such as that shown in Fig. 3A, in accordance with one aspect of the present technology comprises the following functional aspects: a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilising structure 3300, a vent 3400, one form of connection port 3600 for connection to air circuit 4170, and a forehead support 3700. In some forms a functional aspect may be provided by one or more physical components. In some forms, one physical component may provide one or more functional aspects. In use the seal -forming structure 3100 is arranged to surround an entrance to the airways of the patient so as to maintain positive pressure at the entrance(s) to the airways of the patient 1000. The sealed patient interface 3000 is therefore suitable for delivery of positive pressure therapy.4.4 RPT DEVICE

[0119] 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, such as any of the methods, in whole or in part, described herein. The RPT device 4000 may be configured to generate aA2578192 12.0 18flow 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.

[0120] In one form, the RPT device 4000 is constructed and arranged to be capable of delivering a flow of air in a range of -20 L / min to +150 L / min while maintaining a positive pressure of at least 4 cmH20, or at least 10cmH2O, or at least 20 cmH20.

[0121] The RPT device may have an external housing 4010, formed in two parts, an upper portion 4012 and a lower portion 4014. Furthermore, the external housing 4010 may include one or more panel(s) 4015. The RPT device 4000 comprises a chassis 4016 that supports one or more internal components of the RPT device 4000. The RPT device 4000 may include a handle 4018.

[0122] The pneumatic path of the RPT device 4000 may comprise one or more air path items, e.g., an inlet air filter 4112, an inlet muffler 4122, a pressure generator 4140 capable of supplying air at positive pressure (e.g., a blower 4142), an outlet muffler 4124 and one or more transducers 4270, such as pressure sensors and flow rate sensors.

[0123] One or more of the air path items may be located within a removable unitary structure which will be referred to as a pneumatic block 4020. The pneumatic block 4020 may be located within the external housing 4010. In one form a pneumatic block 4020 is supported by, or formed as part of the chassis 4016.

[0124] Electrical components 4200 may be mounted on a single Printed Circuit Board Assembly (PCBA) 4202. In an alternative form, the RPT device 4000 may include more than one PCBA 4202.4.4.1 RPT device mechanical & pneumatic components

[0125] An RPT device may comprise one or more of the following components in an integral unit. In an alternative form, one or more of the following components may be located as respective separate units.4.4.1.1 Air filter (s)

[0126] An RPT device in accordance with one form of the present technology may include an air filter 4110, or a plurality of air filters 4110.

[0127] In one form illustrated in Fig. 4B, an inlet air filter 4112 is located at the beginning of the pneumatic path upstream of a pressure generator 4140.A2578192 12.0 19

[0128] In one form illustrated in Fig. 4B, an outlet air filter 4114, for example an antibacterial filter, is located between an outlet of the pneumatic block 4020 and a patient interface 3000.4.4.1.2 Muffler(s)

[0129] An RPT device in accordance with one form of the present technology may include a muffler 4120, or a plurality of mufflers 4120.

[0130] In one form of the present technology (see e.g., Fig. 4B), an inlet muffler 4122 is located in the pneumatic path upstream of a pressure generator 4140.

[0131] In one form of the present technology, an outlet muffler 4124 is located in the pneumatic path between the pressure generator 4140 and a patient interface 3000.4.4.1.3 Pressure generator

[0132] In one form of the present technology, a pressure generator 4140 for producing a flow, or a supply, of air at positive pressure is a controllable blower 4142. For example, the blower 4142 may include a brushless DC motor 4144 with one or more impellers. The impellers may be located in a volute. The blower may be capable of delivering a supply of air, for example at a rate of up to about 120 litres / minute, at a positive pressure in a range from about 4 cmH20 to about 20 cmH20, or in other forms up to about 30 cmH20 when delivering respiratory pressure therapy. The blower may be as described in any one of the following patents or patent applications the contents of which are incorporated herein by reference in their entirety: U.S.Patent No. 7,866,944; U.S. Patent No. 8,638,014; U.S. Patent No. 8,636,479; and PCT Patent Application Publication No. WO 2013 / 020167.

[0133] The pressure generator 4140 may be under the control of the therapy device controller.

[0134] In other forms, a pressure generator 4140 may be a piston-driven pump, a pressure regulator connected to a high pressure source (e.g. compressed air reservoir), or a bellows.4.4.1.4 Transducer(s)

[0135] Transducers may be internal of the RPT device, or external of the RPT device. External transducers may be located for example on or form part of the air circuit, e.g., the patient interface. External transducers may be in the form of non-A2578192 12.0 20contact sensors such as a Doppler radar movement sensor that transmit or transfer data to the RPT device.

[0136] In one form of the present technology (see e.g., Fig. 4B), one or more transducers 4270 are located upstream and / or downstream of the pressure generator 4140. The one or more transducers 4270 may be constructed and arranged to generate signals representing properties of the flow of air such as a flow rate, a pressure or a temperature at that point in the pneumatic path.

[0137] In one form of the present technology, one or more transducers 4270 may be located proximate to the patient interface 3000.

[0138] In one form, a signal from a transducer 4270 may be filtered, such as by low-pass, high-pass or band-pass filtering.4.4.1.5 Flow rate sensor

[0139] A flow rate sensor in accordance with the present technology may be based on a differential pressure transducer, for example, an SDP600 Series differential pressure transducer from SENSIRION.

[0140] In one form, a signal generated by the flow rate sensor and representing a flow rate is received by the central controller.4.4.1.6 Pressure sensor

[0141] A pressure sensor in accordance with the present technology is located in fluid communication with the pneumatic path. An example of a suitable pressure sensor is a transducer from the HONEYWELL ASDX series. An alternative suitable pressure sensor is a transducer from the NPA Series from GENERAL ELECTRIC.

[0142] In one form, a signal generated by the pressure sensor and representing a pressure is received by the central controller.4.4.1.7 Motor speed transducer

[0143] In one form of the present technology a motor speed transducer is used to determine a rotational velocity of the motor 4144 and / or the blower 4142. A motor speed signal from the motor speed transducer may be provided to the therapy device controller. The motor speed transducer may, for example, be a speed sensor, such as a Hall effect sensor.A2578192 12.0 214.4.1.8 Anti-spill back valve

[0144] As shown in Fig. 4B, one form of the present technology, an anti-spill back valve 4160 is located between the humidifier 5000 and the pneumatic block 4020. The anti-spill back valve is constructed and arranged to reduce the risk that water will flow upstream from the humidifier 5000, for example to the motor 4144.4.4.2 RPT device electrical components4.4.2.1 Power supply

[0145] A power supply 4210 may be located internal or external of the external housing 4010 of the RPT device 4000.

[0146] In one form of the present technology, power supply 4210 provides electrical power to the RPT device 4000 only. In another form of the present technology, power supply 4210 provides electrical power to both RPT device 4000 and humidifier 5000.4.4.2.1 Input devices

[0147] In one form of the present technology, an RPT device 4000 includes one or more input devices 4220 in the form of buttons, switches or dials to allow a person to interact with the device. The buttons, switches or dials may be physical devices, or software devices accessible via a touch screen. The buttons, switches or dials may, in one form, be physically connected to the external housing 4010, or may, in another form, be in wireless communication with a receiver that is in electrical connection to the central controller.

[0148] In one form, the input device 4220 may be constructed and arranged to allow a person to select a value and / or a menu option.4.4.2.3 Central controller

[0149] In one form of the present technology, the central controller is one or a plurality of processors suitable to control an RPT device 4000.

[0150] Suitable processors may include an x86 INTEL processor, a processor based on ARM® Cortex®-M processor from ARM Holdings such as an STM32 series microcontroller from ST MICROELECTRONIC. In certain alternative forms of the present technology, a 32-bit RISC CPU, such as an STR9 series microcontroller from ST MICROELECTRONICS or a 16-bit RISC CPU such as a processor from theA2578192 12.0 22MSP430 family of microcontrollers, manufactured by TEXAS INSTRUMENTS may also be suitable.

[0151] In one form of the present technology, the central controller is a dedicated electronic circuit.

[0152] In one form, the central controller is an application-specific integrated circuit. In another form, the central controller comprises discrete electronic components.

[0153] The central controller may be configured to receive input signal(s) from one or more transducers 4270, one or more input devices 4220, and / or the humidifier 5000.

[0154] The central controller may be configured to provide output signal(s) to one or more of an output device, a pressure generator 4140, a therapy device controller, a data communication interface, and / or the humidifier 5000.

[0155] In some forms of the present technology, the central controller is configured to implement the one or more methodologies described herein, such as the one or more algorithms which may be implemented with processor-control instructions, expressed as computer programs stored in a non-transitory computer readable storage medium, such as memory. In some forms of the present technology, the central controller may be integrated with an RPT device 4000. However, in some forms of the present technology, some methodologies may be performed by a remotely located device. For example, the remotely located device may determine control settings for a ventilator or detect respiratory related events by analysis of stored data such as from any of the sensors described herein.

[0156] In one form of the present technology, supplementary gas, e.g. oxygen, 4180 is delivered to one or more points in the pneumatic path, such as upstream of the pneumatic block 4020, to the air circuit 4170, and / or to the patient interface 3000.4.5 HUMIDIFIER4.5.1 Humidifier overview

[0157] In one form of the present technology there is provided a humidifier 5000 (e.g. as shown in Fig. 5A) to change the absolute humidity of air or gas for delivery to a patient relative to ambient air. Typically, the humidifier 5000 is used to increase the absolute humidity and increase the temperature of the flow of air (relative to ambient air) before delivery to the patient’s airways.A2578192 12.0 23

[0158] The humidifier 5000 may comprise a humidifier reservoir 5110, a humidifier inlet 5002 to receive a flow of air, and a humidifier outlet 5004 to deliver a humidified flow of air. In some forms, as shown in Fig. 5A and Fig. 5B, an inlet and an outlet of the humidifier reservoir 5110 may be the humidifier inlet 5002 and the humidifier outlet 5004 respectively. The humidifier 5000 may further comprise a humidifier base 5006, which may be adapted to receive the humidifier reservoir 5110 and comprise a heating element 5240.

[0159] In examples the humidifier reservoir further comprises a conductive portion 5120, a locking lever 5135 and a water level indicator 5150.

[0160] In one form of the present technology, an anti-spill back valve 4160 is located between the humidifier 5000 and the pneumatic block 4020.

[0161] In some forms of the technology an RPT for use with a patient interface of the present technology may not require a humidifier.4.6 HEAT AND MOISTURE EXCHANGERS (HMX)

[0162] Fig. 7 shows a sheet of HMX material 6010 folded in a Miura-ori configuration according to one form of the technology. The HMX material 6010 may comprise paper, although non-woven fabrics or thin foams may also be used.

[0163] Referring next to Fig. 8, a heat and moisture exchanger, referred to herein as an HMX 6000, may be manufactured from a flat sheet of HMX material 6010.

[0164] The material 6010 may have mountain folds 6020 (shown as solid lines) and valley folds 6030 (shown as dashed lines) which define parallelogram panels 6040 in a tessellating pattern. As used herein, the term “fold line” refers to a notional line along which one or more folds have been or will be made, or to the fold(s) themselves. A “fold” can be either a mountain fold 6020 or a valley fold 6030, but a single fold line may comprise a mountain fold, a valley fold, or a combination of mountain and valley folds.

[0165] The material 6010 may comprise a plurality of first fold lines 6050 comprising parallel straight lines and a plurality of second fold lines 6060 which are parallel zig-zag lines which intersect each of the first fold lines which change direction at each intersection with the first fold lines 6050. The second fold lines form non-orthogonal angles close to 90 degrees with the first fold lines, e.g. 86 degrees and 94 degrees. Each of the second fold lines 6060 is either a mountain fold 6020 or a valley fold 6030 along its entire length, with the mountain and valley folds alternating in the direction of the first fold lines 6050. Each of the first fold lines 6050 comprisesA2578192 12.0 24mountain folds 6020 and valley folds 6030 which alternate where the respective first fold line 6050 intersects the second fold lines 6060.

[0166] Figs. 9A-9C show views of the HMX material 6010 folded in a Miura-ori configuration. When folded, the originally substantially planar material 6010 forms a three-dimensional structure. Notably, in an idealised example, the only deformation of the material 6010 is at the fold lines 6050, 6060, i.e. the panels 6040 themselves remain substantially undeformed as the material 6010 moves from a flat to a fully folded configuration (as described further below).

[0167] Fig. 9C shows a unit cell U of the folded HMX material 6010. The cell has a first pair of adjacent panels 6040A separated by a first valley fold 6030A and a second pair of adjacent panels 6040B separated by a first mountain fold 6020A. The first valley fold 6030 A intersects the first mountain fold 6020 A. The first pair of panels 6040A is connected to the second pair of panels 6040B by a pair of second mountain folds 6020B.

[0168] Referring next to Fig. 9B, when in a partially or fully folded configuration, the lowermost fold lines may all lie on a base plane B. In this configuration, the folded structure has an overall thickness dimension T which is orthogonal to the base plane B. The thickness dimension T may increase as angle A, the angle between the first pair of panels 6040A, decreases (see Fig. 9C). Typically, HMX devices 6000 incorporating HMX material 6010 folded in this way are arranged such that the direction of the net fluid flow F impinging on the HMX material 6010 is substantially parallel to the thickness dimension T in use. The overall thickness T of an HMX 6000 is typically as small as possible while meeting a specified humidification requirement. In one example, the thickness is around 5 mm.

[0169] Referring back to Fig. 9A, the lateral ends 6020C of the second mountain folds 6020B (e.g. the ends distal the respective first mountain folds 6020A) of a pair of adjacent unit cells Ul, U2, which are connected by valley folds 6030 on the base plane B (and thus share a common first fold line), lie on a surface S.

[0170] The surface S forms an “opening” in the folded HMX material 6010. In examples, the HMX material 6010 is arranged such that each surface S is substantially orthogonal to the direction of fluid flow impinging on the HMX 6000 from the patient, in use. As can be seen in Fig. 12C, the HMX 6000 can be deformed or arranged such that the openings lie in different planes. For example, the surfaces SIA2578192 12.0 25defining openings toward the superior end of the HMX 6000 may be orthogonal to fluid flowing in an anterior and inferior direction (e.g. from the patient’s nares), while surfaces S2 defining openings toward the inferior end may be orthogonal to fluid flowing in a generally anterior direction (e.g. from the patient’s mouth). Ensuring that the openings are generally orthogonal to the local direction of fluid flow F reduces the impedance of the HMX 6000 to fluid flow and therefore may reduce rebreathing of CO2.

[0171] In the example shown in Fig. 12C the HMX is arranged in a cylindrical curve, that is, it has a single principal curvature. In other examples, the HMX material 6010 may be deformed or arranged with two principal curvatures (e.g. in a dome shape), e.g. such that openings on one lateral side of the HMX 6000 are at a different angle to openings on the opposite lateral side of the HMX, as well as the superior and inferior openings being at different angles.

[0172] In examples, the thickness of the HMX may remain substantially constant when the HMX is deformed about one or two axes, as described above.

[0173] In the examples shown in Figs. 12A-13B, the HMX material 6010 is in a fully folded configuration. The HMX material 6010 is considered to be in the fully folded configuration when angle A is less than 45 degrees, for example, 35 degrees or less. Typically, angle A cannot reach zero degrees since the second pair of panels 6040B of an adjacent unit cell impinge into the space between the first pair of panels 6040A.

[0174] Referring next to Figs. 7 and 10, in some examples a plurality of apertures 6070 are formed in the HMX material 6010. As shown in Fig. 10, in examples, the apertures 6070 are located such as to be at intersections of first and second fold lines 6050, 6060. As shown in Fig. 11 and 15 A, in examples, apertures 6070 may also be provided in positions which are between adjacent pairs of first fold lines 6050 and between adjacent pairs of second fold lines 6060. In other examples the additional apertures may be on a first fold line 6050 but between adjacent pairs of second fold lines 6060. In examples the apertures may have diameters between 0.2 mm and 5mm.

[0175] The apertures 6070 are preferably spaced apart in a regular pattern. In examples, apertures 6070 are provided at the end of every second segment of the (zigzag) second fold lines 6060, as shown in Fig. 10. The apertures 6070 may be substantially circular (when the material is unfolded). In another example at least some of the apertures 6070 are in the form of slits.A2578192 12.0 26

[0176] Figs. 12A-12C show one form of an HMX 6000 made from HMX material 6010 that has been folded in a Miura-ori pattern. A flange 6080 may be provide to an outer periphery of the folded material 6010 to hold the HMX material 6010 in the fully folded configuration, and to assist in locating or mounting the HMX 6000. In this example, the HMX 6000 has an approximately rectangular shape.

[0177] Referring next to Figs. 13 A and 13B, the HMX 6000 may be connected to an anterior face of a patient interface 3000. In one example the HMX 6000 has a rigid frame which connects to the patient interface 3000 in a clip fit or snap fit manner. In another example, the rigid frame may engage the patient interface in a friction fit.

[0178] Referring next to Fig. 14, in one example an HMX 6000 comprises fully folded HMX material 6010 provided within a substantially cylindrical housing 7000. The housing 7000 may have substantially open ends to allow air to flow through the HMX material 6010. Figs. 15A and 15B show another form of an HMX 6000 with a cylindrical housing 7000.4.7 BREATHING WAVEFORMS

[0179] Fig. 6 shows a model typical breath waveform of a person while sleeping. The horizontal axis is time, and the vertical axis is respiratory flow rate. While the parameter values may vary, a typical breath may have the following approximate values: tidal volume Vt 0.5L, inhalation time Ti 1.6s, peak inspiratory flow rate Qpeak 0.4 L / s, exhalation time Te 2.4s, peak expiratory flow rate Qpeak -0.5 L / s. The total duration of the breath, Ttot, is about 4s. The person typically breathes at a rate of about 15 breaths per minute (BPM), with Ventilation Vent about 7.5 L / min. A typical duty cycle, the ratio of Ti to Ttot, is about 40%.4.8 GLOSSARY

[0180] For the purposes of the present technology disclosure, in certain forms of the present technology, one or more of the following definitions may apply. In other forms of the present technology, alternative definitions may apply.4.8.1 General

[0181] 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.A2578192 12.0 27

[0182] 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.

[0183] 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.

[0184] In another example, ambient pressure may be the pressure immediately surrounding or external to the body.

[0185] 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.

[0186] Automatic Positive Airway Pressure (APAP) therapy: CP AP 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.

[0187] 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.

[0188] 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’.

[0189] 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 flowA2578192 12.0 28rate, Qd, is the flow rate of air leaving the RPT device. Total flow rate, Qt, is the flow rate of air and any supplementary gas reaching the patient interface via the air circuit. Vent flow rate, Qv, is the flow rate of air leaving a vent to allow washout of exhaled gases. Leak flow rate, QI, is the flow rate of leak from a patient interface system or elsewhere. Respiratory flow rate, Qr, is the flow rate of air that is received into the patient's respiratory system.

[0190] 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.

[0191] 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.

[0192] 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.

[0193] 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.

[0194] 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.

[0195] 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.

[0196] 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”.

[0197] Medical Oxygen: Medical oxygen is defined as oxygen enriched air with an oxygen concentration of 80% or greater.A2578192 12.0 29

[0198] Patient: A person, whether or not they are suffering from a respiratory condition.

[0199] Pressure: Force per unit area. Pressure may be expressed in a range of units, including cmFhO, g-f / cm2and hectopascal. 1 cmFFO is equal to 1 g-f / cm2and is approximately 0.98 hectopascal (1 hectopascal = 100 Pa = 100 N / m2= 1 millibar ~ 0.001 atm). In this specification, unless otherwise stated, pressure is given in units of cmFFO.

[0200] 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.

[0201] 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.

[0202] Ventilator: A mechanical device that provides pressure support to a patient to perform some or all of the work of breathing.4.8.1.1 Materials & their properties

[0203] Hardness: Refers to durometer or indentation hardness, which is a material property measured by indentation of an indentor (e.g., as measured in accordance with ASTM D2240).• ‘Soft’ materials may include silicone or thermo-plastic elastomer (TPE), and may, e.g. readily deform under finger pressure.• ‘Hard’ materials may include polycarbonate, polypropylene, and may not e.g. readily deform under finger pressure.

[0204] 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.

[0205] Polycarbonate: a thermoplastic polymer of Bisphenol-A Carbonate.A2578192 12.0 304.8.1.2 Mechanics

[0206] Axes: a. Neutral axis: An axis in the cross-section of a beam or plate along which there are no longitudinal stresses or strains. b. Longitudinal axis: An axis extending along the length of a shape. The axis generally passes through a center of the shape. c. Circumferential axis: An axis oriented perpendicularly with respect to the longitudinal axis. The axis may be specifically present in pipes, tubes, cylinders, or similar shapes with a circular and / or elliptical cross section.

[0207] Deformation: The process where the original geometry of a member changes when subjected to forces, e.g. a force in a direction with respect to an axis. The process may include stretching or compressing, bending and, twisting.

[0208] Elasticity: The ability of a material to return to its original geometry after deformation.

[0209] Floppy structure or component: A structure or component that will change shape, e.g. bend, when caused to support its own weight, within a relatively short period of time such as 1 second.

[0210] Resilience: Ability of a material to absorb energy when deformed elastically and to release the energy upon unloading.

[0211] Resilient: Will release substantially all of the energy when unloaded. Includes e.g. certain silicones, and thermoplastic elastomers.

[0212] Rigid structure or component: A structure or component that will not substantially change shape when subject to the loads typically encountered in use. An example of such a use may be setting up and maintaining a patient interface in sealing relationship with an entrance to a patient's airways, e.g. at a load of approximately 20 to 30 cmH20 pressure.

[0213] As an example, an I-beam may comprise a different bending stiffness (resistance to a bending load) in a first direction in comparison to a second, orthogonal direction. In another example, a structure or component may be floppy in a first direction and rigid in a second direction.

[0214] Stiffness (or rigidity) of a structure or component: The ability of the structure or component to resist deformation in response to an applied load. The load may be a force or a moment, e.g. compression, tension, bending or torsion. TheA2578192 12.0 31structure or component may offer different resistances in different directions. The inverse of stiffness is flexibility.

[0215] Viscous: The ability of a material to resist flow.

[0216] Visco-elasticity: The ability of a material to display both elastic and viscous behaviour in deformation.

[0217] Yield: The situation when a material can no longer return back to its original geometry after deformation.4.8.1.3 Structural Elements

[0218] Compression member: A structural element that resists compression forces.

[0219] 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.

[0220] 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.

[0221] 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.

[0222] Tie (noun): A structure designed to resist tension.

[0223] Thin structures: a. Beams, i. A beam may be relatively long in one dimension compared to the other two dimensions such that the smaller dimensions are comparatively thin compared to the long dimension b. Membranes,A2578192 12.0 32i. Relatively long in two dimensions, with one thin dimension. Readily deforms in response to bending forces. Resists being stretched, (might also resist compression). c. Plates & Shells i. These may be relatively long in two directions, with one thin dimension. They may have bending, tensile, and / or compressive stiffness.

[0224] Thick structures: Solids

[0225] 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.

[0226] 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.

[0227] 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.

[0228] 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.

[0229] 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.4.8.2 Shape of structures

[0230] Products in accordance with the present technology may comprise one or more three-dimensional mechanical structures, for example a mask cushion or an impeller. The three-dimensional structures may be bounded by two-dimensional surfaces. These surfaces may be distinguished using a label to describe an associatedA2578192 12.0 33surface orientation, location, function, or some other characteristic. For example a structure may comprise one or more of an anterior surface, a posterior surface, an interior surface and an exterior surface. In another example, a seal-forming structure may comprise a face-contacting (e.g. outer) surface, and a separate non-facecontacting (e.g. underside or inner) surface. In another example, a structure may comprise a first surface and a second surface.

[0231] To facilitate describing the shape of the three-dimensional structures and the surfaces, we first consider a cross-section through a surface of the structure at a point, p. See Fig. 3B to Fig. 3F, which illustrate examples of cross-sections at point p on a surface, and the resulting plane curves. Figs. 3B to 3F also illustrate an outward normal vector at p. The outward normal vector at p points away from the surface. In some examples we describe the surface from the point of view of an imaginary small person standing upright on the surface.4.8.2.1 Curvature in one dimension

[0232] The curvature of a plane curve at p may be described as having a sign (e.g. positive, negative) and a magnitude (e.g. 1 / radius of a circle that just touches the curve at p).

[0233] Positive curvature: If the curve at p turns towards the outward normal, the curvature at that point will be taken to be positive (if the imaginary small person leaves the point p they must walk uphill). See Fig. 3B (relatively large positive curvature compared to Fig. 3C) and Fig. 3C (relatively small positive curvature compared to Fig. 3B). Such curves are often referred to as concave.

[0234] Zero curvature: If the curve at p is a straight line, the curvature will be taken to be zero (if the imaginary small person leaves the point p, they can walk on a level, neither up nor down). See Fig. 3D.

[0235] Negative curvature: If the curve at p turns away from the outward normal, the curvature in that direction at that point will be taken to be negative (if the imaginary small person leaves the point p they must walk downhill). See Fig. 3E (relatively small negative curvature compared to Fig. 3F) and Fig. 3F (relatively large negative curvature compared to Fig. 3E). Such curves are often referred to as convex.4.8.2.1 Curvature of two dimensional surfaces

[0236] A description of the shape at a given point on a two-dimensional surface in accordance with the present technology may include multiple normal crosssections. The multiple cross-sections may cut the surface in a plane that includes theA2578192 12.0 34outward normal (a “normal plane”), and each cross-section may be taken in a different direction. Each cross-section results in a plane curve with a corresponding curvature. The different curvatures at that point may have the same sign, or a different sign.Each of the curvatures at that point has a magnitude, e.g. relatively small. The plane curves in Figs. 3B to 3F could be examples of such multiple cross-sections at a particular point.

[0237] Principal curvatures and directions: The directions of the normal planes where the curvature of the curve takes its maximum and minimum values are called the principal directions. In the examples of Fig. 3B to Fig. 3F, the maximum curvature occurs in Fig. 3B, and the minimum occurs in Fig. 3F, hence Fig. 3B and Fig. 3F are cross sections in the principal directions. The principal curvatures at p are the curvatures in the principal directions.

[0238] Region of a surface: A connected set of points on a surface. The set of points in a region may have similar characteristics, e.g. curvatures or signs.

[0239] Saddle region: A region where at each point, the principal curvatures have opposite signs, that is, one is positive, and the other is negative (depending on the direction to which the imaginary person turns, they may walk uphill or downhill).

[0240] Dome region: A region where at each point the principal curvatures have the same sign, e.g. both positive (a “concave dome”) or both negative (a “convex dome”).

[0241] Cylindrical region: A region where one principal curvature is zero (or, for example, zero within manufacturing tolerances) and the other principal curvature is non-zero.

[0242] Planar region: A region of a surface where both of the principal curvatures are zero (or, for example, zero within manufacturing tolerances).

[0243] Edge of a surface: A boundary or limit of a surface or region.

[0244] Path: In certain forms of the present technology, ‘path’ will be taken to mean a path in the mathematical - topological sense, e.g. a continuous space curve from f(0) to f(l) on a surface. In certain forms of the present technology, a ‘path’ may be described as a route or course, including e.g. a set of points on a surface. (The path for the imaginary person is where they walk on the surface, and is analogous to a garden path).

[0245] Path length: In certain forms of the present technology, ‘path length’ will be taken to mean the distance along the surface from f(0) to f(l), that is, the distanceA2578192 12.0 35along the path on the surface. There may be more than one path between two points on a surface and such paths may have different path lengths. (The path length for the imaginary person would be the distance they have to walk on the surface along the path).

[0246] Straight-line distance: The straight-line distance is the distance between two points on a surface, but without regard to the surface. On planar regions, there would be a path on the surface having the same path length as the straight-line distance between two points on the surface. On non-planar surfaces, there may be no paths having the same path length as the straight-line distance between two points. (For the imaginary person, the straight-line distance would correspond to the distance ‘as the crow flies’.)4.8.1.3 Space curves

[0247] Space curves: Unlike a plane curve, a space curve does not necessarily lie in any particular plane. A space curve may be closed, that is, having no endpoints. A space curve may be considered to be a one-dimensional piece of three-dimensional space. An imaginary person walking on a strand of the DNA helix walks along a space curve. A typical human left ear comprises a helix, which is a left-hand helix, see Fig. 3Q. A typical human right ear comprises a helix, which is a right-hand helix, see Fig. 3R. Fig. 3S shows a right-hand helix. The edge of a structure, e.g. the edge of a membrane or impeller, may follow a space curve. In general, a space curve may be described by a curvature and a torsion at each point on the space curve. Torsion is a measure of how the curve turns out of a plane. Torsion has a sign and a magnitude. The torsion at a point on a space curve may be characterised with reference to the tangent, normal and binormal vectors at that point.

[0248] Tangent unit vector (or unit tangent vector): For each point on a curve, a vector at the point specifies a direction from that point, as well as a magnitude. A tangent unit vector is a unit vector pointing in the same direction as the curve at that point. If an imaginary person were flying along the curve and fell off her vehicle at a particular point, the direction of the tangent vector is the direction she would be travelling.

[0249] Unit normal vector: As the imaginary person moves along the curve, this tangent vector itself changes. The unit vector pointing in the same direction that the tangent vector is changing is called the unit principal normal vector. It is perpendicular to the tangent vector.A2578192 12.0 36

[0250] Binormal unit vector: The binormal unit vector is perpendicular to both the tangent vector and the principal normal vector. Its direction may be determined by a right-hand rule (see e.g. Fig. 3P), or alternatively by a left-hand rule (Fig. 30).

[0251] Osculating plane: The plane containing the unit tangent vector and the unit principal normal vector. See Figures 30 and 3P.

[0252] Torsion of a space curve: The torsion at a point of a space curve is the magnitude of the rate of change of the binormal unit vector at that point. It measures how much the curve deviates from the osculating plane. A space curve which lies in a plane has zero torsion. A space curve which deviates a relatively small amount from the osculating plane will have a relatively small magnitude of torsion (e.g. a gently sloping helical path). A space curve which deviates a relatively large amount from the osculating plane will have a relatively large magnitude of torsion (e.g. a steeply sloping helical path). With reference to Fig. 3S, since T2>T1, the magnitude of the torsion near the top coils of the helix of Fig. 3S is greater than the magnitude of the torsion of the bottom coils of the helix of Fig. 3S

[0253] With reference to the right-hand rule of Fig. 3P, a space curve turning towards the direction of the right-hand binormal may be considered as having a righthand positive torsion (e.g. a right-hand helix as shown in Fig. 3S). A space curve turning away from the direction of the right-hand binormal may be considered as having a right-hand negative torsion (e.g. a left-hand helix).

[0254] Equivalently, and with reference to a left-hand rule (see Fig. 30), a space curve turning towards the direction of the left-hand binormal may be considered as having a left-hand positive torsion (e.g. a left-hand helix). Hence left-hand positive is equivalent to right-hand negative. See Fig. 3T.4.8.1.4 Holes

[0255] A surface may have a one-dimensional hole, e.g. a hole bounded by a plane curve or by a space curve. Thin structures (e.g. a membrane) with a hole, may be described as having a one-dimensional hole. See for example the one dimensional hole in the surface of structure shown in Fig. 31, bounded by a plane curve.

[0256] A structure may have a two-dimensional hole, e.g. a hole bounded by a surface. For example, an inflatable tyre has a two dimensional hole bounded by the interior surface of the tyre. In another example, a bladder with a cavity for air or gel could have a two-dimensional hole. See for example the cushion of Fig. 3L and the example cross-sections therethrough in Fig. 3M and Fig. 3N, with the interior surfaceA2578192 12.0 37bounding a two dimensional hole indicated. In a yet another example, a conduit may comprise a one-dimension hole (e.g. at its entrance or at its exit), and a two-dimension hole bounded by the inside surface of the conduit. See also the two dimensional hole through the structure shown in Fig. 3K, bounded by a surface as shown.4.9 OTHER REMARKS

[0257] 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.

[0258] 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.

[0259] 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.

[0260] Furthermore, “approximately”, “substantially”, “about”, or any similar term used herein means + / - 5-10% of the recited value.

[0261] 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.

[0262] When a particular material is identified as being used to construct a component, obvious alternative materials with similar properties may be used as aA2578192 12.0 38substitute. 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.

[0263] 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.

[0264] 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.

[0265] 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.

[0266] 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.

[0267] 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.A2578192 12.0 39

[0268] 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.A2578192 12.0 40

Claims

5 CLAIMS1. A heat and moisture exchanger (HMX) comprising a folded HMX material, wherein the HMX material comprises a plurality of parallel first fold lines and a plurality of second fold lines, the second fold lines being zig-zag lines which intersect each of the first fold lines, wherein the second fold lines change direction at each intersection with the first fold lines, the first and second fold lines defining a plurality of tessellating parallelogram shaped panels, wherein the first fold lines alternate between mountain folds and valley folds at each intersection with the second fold lines. wherein the second fold lines comprise alternate mountain folds and valley folds.

2. The HMX of claim 1, wherein the HMX material comprises a plurality of unit cells, each unit cell having a first pair of adjacent panels and a second pair of adjacent panels, wherein a boundary between the panels of each pair of panels is defined by one of the first fold lines, wherein the first fold line between the first pair of panels is arranged as a valley fold and the first fold line between the second pair of panels is arranged as a mountain fold, and wherein a boundary between the first pair of panels and the second pair of adjacent panels is defined by one of the second fold lines which is arranged as a mountain fold, and wherein the HMX material is arranged such that the angle between the first pair of panels is less than 45 degrees.

3. The HMX of claim 2, wherein the angle between the first pair of panels is less than 35 degrees.

4. The HMX of claim 2 or 3, wherein an aperture is provided at each end of each mountain fold or each valley fold.A2578192 12.0 415. The HMX of claim 4, wherein additional apertures are provided mid way along a plurality of the mountain folds and / or a plurality of the valley folds.

6. A heat and moisture exchanger (HMX) comprising an HMX material folded in a Miura-ori configuration.

7. The HMX of claim 6, wherein the HMX material comprises a plurality of unit cells, each unit cell having a first pair of adjacent panels and a second pair of adjacent panels, wherein a boundary between the panels of each pair of panels is defined by a first fold line, wherein the first fold line between the first pair of panels is arranged as a valley fold and the first fold line between the second pair of panels is arranged as a mountain fold, and wherein a boundary between the first pair of panels and the second pair of adjacent panels is defined by a second fold line which is arranged as a mountain fold, and wherein the HMX material is arranged such that the angle between the first pair of panels is less than 45 degrees.

8. The HMX of claim 6, wherein the angle between the first pair of panels is less than 35 degrees.

9. The HMX of claim 7 or 8, wherein an aperture is provided at each end of each mountain fold or each valley fold.

10. The HMX of claim 9, wherein additional apertures are provided mid way along a plurality of the mountain folds and / or a plurality of the valley folds.

11. A heat and moisture exchanger (HMX) comprising an HMX material folded in a Miura-ori configuration comprising a plurality of pairs of unit cells, each unit cell comprising:A2578192 12.0 42a first pair of adjacent panels and a second pair of adjacent panels, wherein a boundary between each panel in each pair of panels is defined by a first fold line, wherein the first fold line between the first pair of panels is arranged as a valley fold and the first fold line between the second pair of panels is arranged as a mountain fold, wherein a boundary between the first pair of panels and the second pair of panels is defined by a second fold line which is arranged as a mountain fold, wherein the unit cells in each pair of unit cells are connected together such that they share a common first fold line, wherein the lateral ends of the second fold lines of each unit cell in each pair of unit cells lie on a common surface, and wherein the HMX material is arranged such that the surface of one of the pairs of unit cells is non-planar with the surface of another of the pairs of unit cells.A2578192 12.0 43

Images