Patient Interface Systems and Respiratory Treatment Systems

Abstract

To provide a patient interface for supplying a flow of breathable gas to the airways of a patient.SOLUTION: A patient interface for supplying a flow of breathable gas to the airways of a patient may comprise a heat and moisture exchanger (HME). The heat and moisture exchanger (HME) may be positioned in a flow path of the flow of breathable gas. The heat and moisture exchanger (HME) may absorb heat and moisture from gas exhaled by the patient, and the incoming flow of breathable gas to be supplied to the patient's airways may be heated and moisturized by the heat and moisture held in the heat and moisture exchanger (HME).SELECTED DRAWING: Figure 9A

Description

[Technical Field]

[0001] 1 Cross-reference to related applications This application claims priority to Australian Patent Application Publication No. 2013902810, filed July 29, 2013, and New Zealand Patent Application Publication No. 613874, filed August 7, 2013, each of which is incorporated by reference in its entirety. [Background technology]

[0002] 2. Technical Background 2.1 Technology field The present technology relates to one or more of the detection, diagnosis, treatment, prevention, and amelioration of respiratory-related disorders. In particular, the present technology relates to medical devices or instruments and uses thereof.

[0003] 2.2 Description of Related Art 2.2.1 Human respiratory system and its diseases The body's respiratory system facilitates gas exchange. The nose and mouth form the entrance to a patient's airways.

[0004] The airways consist of a series of branches that become narrower, shorter, and more numerous as they penetrate deeper into the lungs. The primary function of the lungs is gas exchange, allowing oxygen to move from the air into the venous blood and carbon dioxide to move out. The trachea divides into left and right main bronchi, which ultimately divide into terminal bronchioles. The bronchi form conducting airways and do not participate in gas exchange. Further division of the airways leads to respiratory bronchioles and ultimately to the alveoli. The alveolar region of the lung, where gas exchange occurs, is called the respiratory zone. See "Respiratory Physiology," 9th Edition, by John B. West, Lippincott Williams & Wilkins, 2011.

[0005] There are a variety of respiratory disorders, and specific disorders may be characterized by specific events, such as apneas, hypopneas, and hyperpneas.

[0006] Obstructive sleep apnea (OSA), a form of sleep-disordered breathing (SDB), is characterized by events involving the obstruction or closure of the upper airway during sleep. Obstructive sleep apnea (OSA) results from an abnormally small upper airway combined with the normal loss of muscle tone in the tongue, soft palate, and posterior oropharyngeal wall regions during sleep. The condition causes affected individuals to stop breathing, typically for periods lasting 30 to 120 seconds, sometimes 200 to 300 times per night. This often leads to excessive daytime somnolence and may lead to cardiovascular disease and brain damage. The syndrome is particularly common in middle-aged and elderly obese men, although sufferers may be unaware of the problem. See U.S. Pat. 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 rhythmic alternating periods of increased and decreased ventilation, known as CSR cycles, are present. CSR is characterized by repeated deoxygenation and reoxygenation of arterial blood. CSR is considered harmful due to repeated hypoxia. In some patients, CSR is associated with repeated arousals from sleep, causing severe sleep disruption, increased sympathetic activity, and increased afterload. See U.S. Patent No. 6,532,959 (Berthon-Jones).

[0008] Obesity hypoventilation syndrome (OHS) is defined as the combination of severe obesity and awake chronic hypercapnia in the absence of other known causes of hypoventilation. Symptoms include dyspnea, morning headache, and excessive daytime sleepiness.

[0009] Chronic obstructive pulmonary disease (COPD) encompasses any group of lower respiratory tract diseases that share certain characteristics. These characteristics include increased resistance to air movement, a prolonged expiratory phase of breathing, and loss of normal lung elasticity. Examples of COPD are emphysema and chronic bronchitis. COPD is caused by chronic tobacco smoking (the primary risk factor), occupational exposure, air pollution, and genetic factors. Symptoms include dyspnea on exertion, chronic cough, and sputum production.

[0010] Neuromuscular disease (NMD) is a broad term that encompasses many diseases and illnesses that impair muscle function directly through intrinsic muscle pathology or indirectly through nerve pathology. Some NMD patients are characterized by progressive muscle dysfunction resulting in loss of walking ability, wheelchair confinement, swallowing difficulties, respiratory muscle weakness, and ultimately death due to respiratory failure. Neuromuscular diseases are divided into rapidly progressive and slowly progressive diseases: (i) rapidly progressive diseases: characterized by muscle dysfunction that worsens over months and leads to death within years (e.g., amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers); (ii) variably progressive or slowly progressive diseases: characterized by muscle dysfunction that worsens over years and only slightly reduces life expectancy (e.g., limb-girdle muscular dystrophy, facioscapulohumeral muscular dystrophy, and myotonic dystrophy). Symptoms of respiratory failure in neuromuscular diseases (NMD) include increasing generalized weakness, difficulty swallowing, difficulty breathing on exertion and at rest, fatigue, drowsiness, morning headache, and difficulty concentrating and changing mood.

[0011] Chest wall disorders are a group of thoracic deformities that result in inefficient coupling between the respiratory muscles and the rib cage. The disorders are usually characterized by restrictive disorders and share the potential for long-term hypercapnic respiratory failure. Scoliosis and / or kyphoscoliosis can cause severe respiratory failure. Symptoms of respiratory failure include dyspnea on exertion, peripheral edema, orthopnea, recurrent pulmonary infections, morning headache, fatigue, poor sleep quality, and decreased appetite.

[0012] A range of treatments have been used to treat or ameliorate such conditions, and in other cases, healthy individuals have successfully used such treatments to prevent the onset of respiratory disease, but these have many drawbacks.

[0013] 2.2.2 Treatment Nasal continuous positive airway pressure (CPAP) therapy has been used to treat obstructive sleep apnea (OSA). The premise is that continuous positive airway pressure can prevent upper airway obstruction by acting as a pneumatic splint and forcing the soft palate and tongue forward and away from the posterior oropharyngeal wall. Treatment of obstructive sleep apnea (OSA) with nasal continuous positive airway pressure (CPAP) therapy can be voluntary, and thus patients may choose not to adhere to treatment if they find the devices used to deliver such therapy to be one or more of: uncomfortable, difficult to use, expensive, or aesthetically unappealing.

[0014] Noninvasive ventilation (NIV) provides ventilatory support to a patient through the upper airway to help the patient take a deep breath and / or maintain adequate oxygen levels in the body by performing some or all of the work of breathing. Ventilatory support is provided via a patient interface. Noninvasive ventilation (NIV) has been used to treat Cheyne-Stokes respiration (CSR), obesity hypoventilation syndrome (OHS), chronic obstructive pulmonary disease (COPD), MD, and chest wall disease. In some forms, the comfort and effectiveness of these treatments may be improved.

[0015] Invasive ventilation (IV) provides ventilatory support to patients who can no longer breathe effectively on their own and may be given using a tracheostomy tube. Some forms may improve the comfort and effectiveness of these treatments.

[0016] 2.2.3 Diagnostic and Therapeutic Systems These treatments may be provided by a treatment system or device. The systems and devices may be used to diagnose medical conditions without treating the medical conditions.

[0017] The therapy system may include a respiratory pressure therapy device (RPT device), an air circuit, a humidifier, a patient interface, and data management.

[0018] Another form of treatment system is a mandibular repositioning device.

[0019] 2.2.3.1 Patient Interface A patient interface may be used to connect a respiratory device to its user, for example, by providing a flow of air. The flow of air may be provided via a mask to the nose and / or mouth, via a tube to the mouth, or via a tracheostomy tube to the user's trachea. Depending on the treatment to be applied, the patient interface may form a seal with, for example, the patient's facial area to facilitate delivery of gas at a pressure sufficient to provide treatment, e.g., approximately 10 cmH2O of positive pressure. For other forms of treatment, such as delivery of oxygen, the patient interface may not include a seal sufficient to facilitate delivery of a predetermined amount of gas to the airways at approximately 10 cmH2O of positive pressure.

[0020] Designing a patient interface presents many challenges. The face has a complex three-dimensional shape. Nose size and shape vary considerably between individuals. Because the head contains bone, cartilage, and soft tissue, different regions of the face respond differently to mechanical forces. The jaw or mandible may move relative to other bones of the skull. The entire head may move during the course of a respiratory treatment session.

[0021] As a result of these challenges, some masks suffer from one or more of the following: being highly noticeable, aesthetically undesirable, expensive, fitting poorly, difficult to use, and uncomfortable, especially when worn for extended periods of time or when the patient is unfamiliar with the system. For example, masks designed only for aviators, masks designed as part of personal protective equipment, SCUBA masks, or masks designed for the administration of anesthetic agents may be acceptable in their original application, but are nevertheless uncomfortable and undesirable to wear for extended periods of time, such as for several hours. This discomfort can lead to a decrease in patient compliance with treatment, especially if the mask must be worn while sleeping.

[0022] Nasal continuous positive airway pressure (CPAP) therapy is highly effective in treating certain respiratory conditions if patients adhere to therapy. Patients may not adhere to therapy if the mask is uncomfortable or difficult to use. Because patients are often recommended to wash their masks regularly, if the mask is difficult to clean (e.g., difficult to assemble or disassemble), patients may not clean their mask, which may affect patient adherence.

[0023] Masks for other uses (e.g., aviators) may not be suitable for use in treating sleep-disordered breathing, but masks designed for use in treating sleep-disordered breathing may be suitable for other uses.

[0024] For these reasons, patient interfaces for delivering nasal continuous positive airway pressure (CPAP) during sleep represent a distinct field.

[0025] 2.2.3.1.1 Seal forming part The patient interface may include a seal-forming portion, and since the seal-forming portion is in direct contact with the patient's face, the shape and configuration of the seal-forming portion can directly affect the effectiveness and comfort of the patient interface.

[0026] Patient interfaces may be characterized in part according to the design intent of the seal-forming portion when it is intended to engage the face in use. In one form of patient interface, the seal-forming portion may comprise two dependent portions for engaging the respective left and right nostrils. In one form of patient interface, the seal-forming portion may comprise a single element that surrounds both nostrils in use. Such a single element may be adapted to overlap, for example, the upper lip region and the nasal bridge region of the face. In one form of patient interface, the seal-forming portion may comprise an element that surrounds the mouth region in use, for example, by forming a seal against the lower lip region of the face. In one form of patient interface, the seal-forming portion may comprise a single element that surrounds both the nostril and mouth regions in use. These different types of patient interfaces are known by various names depending on their manufacturer, including nasal masks, full-face masks, nasal pillows, nasal puffs, and oronasal masks.

[0027] A seal-forming portion that may be effective in one area of ​​a patient's face may not be suitable in other areas due to, for example, different shapes, structures, variations, and sensitive areas of the patient's face. For example, a seal in swim goggles that overlaps the patient's forehead may not be suitable for use on the patient's nose.

[0028] A particular seal-forming portion may be designed for mass production so that one configuration will fit a wide range of different facial shapes and sizes while being comfortable and effective. To the extent that there is a mismatch between the shape of the patient's face and the seal-forming portion of a mass-produced patient interface, one or both must match in order for a seal to occur.

[0029] One type of seal-forming portion extends around the periphery of the patient interface and is adapted to seal against the user's face when force is applied to the patient interface with the seal-forming portion in abutting engagement with the user's face. The seal-forming portion may include an air- or fluid-filled cushion or a molded or formed surface of a resilient sealing element formed from an elastomer such as rubber. With this type of seal-forming portion, if the fit is not proper, there will be gaps between the seal-forming portion and the face, and additional force will be required to press the patient interface against the face and achieve a seal.

[0030] Other types of seal-forming devices incorporate a flap seal of thin material positioned around the periphery of the mask to self-seal against the user's face when positive pressure is applied within the mask. As with previous styles of seal-forming devices, if the fit between the face and the mask is poor, additional force may be required to create a seal, or the mask may leak unintentionally. Also, if the shape of the seal-forming device does not match the shape of the patient, the seal-forming device may fold or buckle during use, resulting in unintentional leakage.

[0031] Other types of seal-forming portions may include friction-fit elements for insertion into the nostrils, for example, but some patients find these uncomfortable.

[0032] Other forms of seal-forming parts may use adhesives to create a seal, and some patients may find it inconvenient to constantly apply and remove adhesive from their face.

[0033] A range of patient interface seal forming technologies are disclosed in the following patent applications assigned to ResMed Limited: WO 1998 / 004,310; WO 2006 / 074,513; and WO 2010 / 135,785.

[0034] One form of nasal pillow is found in the Adam Circuit manufactured by Puritan Bennett. Another nasal pillow or nasal puff is the subject of U.S. Pat. No. 4,782,832 (Trimble et al.), assigned to Puritan Bennett Corporation.

[0035] ResMed Limited has manufactured the following products that incorporate nasal pillows: the SWIFT® Nasal Pillows Mask, the SWIFT® II Nasal Pillows Mask, the SWIFT® LT Nasal Pillows Mask, the SWIFT® FX Nasal Pillows Mask, and the LIBERTY Full Face Mask. The following patent applications assigned to ResMed Limited describe nasal pillow masks: WO 2004 / 073,778 (which describes, among other things, aspects of ResMed SWIFT® nasal pillows); U.S. Patent Application Publication No. 2009 / 0044808 (which describes, among other things, aspects of ResMed SWIFT® LT nasal pillows); WO 2005 / 063,328 and WO 2006 / 130,903 (which describe, among other things, aspects of ResMed LIBERTY full face masks); and WO 2009 / 052,560 (which describes, among other things, aspects of ResMed SWIFT® FX nasal pillows).

[0036] 2.2.3.1.2 Positioning stabilization The seal-forming portions of patient interfaces used for positive air pressure therapy are subjected to the corresponding forces of air pressure that can compromise the seal. Accordingly, various techniques have been used to position the seal-forming portion and maintain it in sealing relationship with the appropriate portion of the face.

[0037] One technique is the use of adhesives, see, for example, US Patent Application Publication No. 2010 / 0000534, however, these can be uncomfortable for some patients.

[0038] Another technique is the use of one or more straps and stabilizing harnesses. Many such harnesses suffer from one or more of the following: being ill-fitting, bulky, uncomfortable, and difficult to use.

[0039] 2.2.3.1.3 Venting Technology Some forms of patient interface systems may include a vent to allow the outflow of exhaled carbon dioxide. The vent may allow gas flow from an interior space of the patient interface, e.g., a plenum chamber, to an exterior of the patient interface, e.g., the ambient environment. The vent may include an orifice through which gas may flow when the mask is in use. Many such vents are noisy. Other vents may become blocked during use, resulting in insufficient outflow. Some vents may disrupt the sleep of the patient's 1000 bed partner 1100, for example, by noise or focused airflow.

[0040] ResMed Limited has developed many improved mask venting technologies, see International Patent Application Publication Nos. WO 1998 / 034,665; WO 2000 / 078,381; U.S. Patent No. 6,581,594; U.S. Patent Application Publication No. 2009 / 0050156; and U.S. Patent Application Publication No. 2009 / 0044808.

[0041] [Table 1]

[0042] Sound pressure level values ​​for various targets are listed below.

[0043] [Table 2]

[0044] 2.2.3.2 Respiratory Pressure Therapy (RPT) Devices Air pressure generators are known for a range of applications, for example, in industrial-scale ventilation systems. However, air pressure generators for medical applications have specific requirements that are not met by more common air pressure generators, such as the reliability, size, and weight requirements of medical devices. Furthermore, even devices designed for medical treatment may suffer from drawbacks including one or more of comfort, noise, ease of use, effectiveness, size, weight, manufacturability, cost, and reliability.

[0045] One example of a special requirement of a particular RPT device is acoustic noise.

[0046] [Table 3]

[0047] One known respiratory pressure therapy (RPT) device used to treat sleep-disordered breathing is the S9 Sleep Therapy System manufactured by ResMed. Another example of a respiratory pressure therapy (RPT) device is a ventilator. Ventilators, such as the ResMed Stellar™ series of adult and pediatric ventilators, can provide invasive and non-invasive independent ventilatory support for a range of patients to treat a number of conditions, including, but not limited to, neuromuscular diseases (NMD), obesity hypoventilation syndrome (OHS), and chronic obstructive pulmonary disease (COPD).

[0048] The ResMed Elisee™ 150 ventilator and ResMed VS III™ ventilators can provide invasive and non-invasive dependent ventilation support suitable for adult or pediatric patients to treat many medical conditions. These ventilators provide volume and pressure ventilation modes using single or dual limb circuits. Respiratory pressure therapy (RPT) devices generally include a pressure generator, such as a motor-driven blower or compressed gas reservoir, and are configured to deliver a flow of air to the patient's airway. In some cases, the air flow may be delivered to the patient's airway at positive pressure. The outlet of the RPT device is connected via an air circuit to a patient interface, such as the patient interface described above.

[0049] 2.2.3.3 Humidifier Delivery of airflow without humidification can cause drying of the airway. The use of a humidifier with a respiratory pressure therapy (RPT) device and patient interface produces humidified gas that minimizes drying of the nasal mucosa and increases comfort for the patient's airway. Also, in cooler climates, warm air applied to the facial area in and around the patient interface is generally more comfortable than cool air. A range of artificial humidifiers and humidification systems are known, but these may not meet the special requirements of a medical humidifier.

[0050] Medical humidifiers are used to increase the humidity and / or temperature of an airflow relative to ambient air when needed, typically while a patient is sleeping or resting (e.g., in a hospital). As a result, medical humidifiers may be small for bedside placement and may be configured to only humidify and / or heat the airflow delivered to a patient without humidifying and / or heating the patient's surrounding environment. For example, while room-based systems (e.g., saunas, air conditioners, evaporative coolers) can also humidify the air inhaled by a patient, these systems may also humidify and / or heat the entire room, which may cause discomfort to the occupants. Furthermore, medical humidifiers may have stricter safety constraints than industrial humidifiers.

[0051] Although many medical humidifiers are known, these humidifiers may suffer from one or more drawbacks: some medical humidifiers may provide insufficient humidification, and some humidifiers are difficult or inconvenient for patients to use.

[0052] 2.2.4 Heat Moisture Exchanger (HME) Heat and moisture exchangers are generally made from foam, paper, or materials that can act as condensing and absorbing surfaces. The materials may be accompanied by hygroscopic salts to improve their moisture-holding capacity. Suitable salts include calcium chloride.

[0053] A heat and moisture exchanger (HME) may be utilized in RPT therapy, such as PAP therapy, to partially restore heat and moisture present in exhaled gases from the patient's airway. This heat and moisture can be passively retained and recirculated to the patient as the breathable gas flow passes through the HME before inspiration. Thus, the use of an HME can provide the moisture and humidity (typically recognized as >10 mg / L) required for most patients during PAP therapy, avoiding the need for a heated humidifier system while minimizing any adverse effects associated with PAP therapy using unhumidified ambient air. Using an HME rather than a heated humidifier can also reduce the likelihood of blockages caused by condensation in the air delivery tubing.

[0054] The use of a heat and moisture exchanger (HME) in PAP therapy avoids the additional power requirements associated with heated humidifiers and reduces the need for extraneous associated components, which can reduce manufacturing costs and the overall size of a continuous positive airway pressure (CPAP) therapy unit.

[0055] A common challenge with the use of heat and moisture exchangers (HMEs) in continuous positive airway pressure (CPAP) therapy relates to the HME's ability to deliver sufficient heat and moisture while also minimizing flow impedance and maintaining a comfortable and safe level of CO2 outflow. Flow impedance can affect patient respiratory effort (work of breathing) and can affect event (apnea, hypopnea, snoring) detection algorithms, and therefore is often desired to be minimized. Heat and moisture loss through ventilation should also be considered, and the HME should function to prevent this loss.

[0056] Current configurations of HMEs in RPT therapy have proven to provide negligible patient humidification and have problems with flow impedance and / or CO2 spillover. For example, placing an HME unit in the elbow around the exhaust vent or on the flow generator side of a therapy system has the advantage of negligible patient humidification (hygroscopicity), but has presented problems with impedance and / or CO2 spillover. In this configuration, vent flow is the primary flow through the HME. Vent flow is flow from the patient or flow generator that flows through the HME and exits directly through the vent. Additionally, current configurations of HMEs do not allow sufficient fluid exchange during patient exhalation to provide adequate humidification levels to the patient. Therefore, there is a need to provide a superior design and configuration for HME use in RPT therapy, such as PAP therapy, to achieve desired patient humidification while having acceptable impedance to therapy flow and acceptable CO2 spillover. Summary of the Invention [Problem to be solved by the invention]

[0057] 3. A brief overview of the technology The present technology is directed to providing medical devices for use in the diagnosis, amelioration, treatment, or prevention of respiratory disorders that have one or more of improved comfort, cost, effectiveness, ease of use, and manufacturability.

[0058] A first aspect of the present technology relates to devices for use in the diagnosis, amelioration, treatment or prevention of respiratory disease.

[0059] Another aspect of the present technology relates to methods for use in the diagnosis, amelioration, treatment, or prevention of respiratory disorders. [Means for solving the problem]

[0060] One form of the present technology comprises a patient interface for delivering a breathable gas flow to an entrance of a patient's airways, including at least the entrances of the patient's nares, the patient interface comprising a heat and moisture exchanger (HME) comprising at least one corrugated structure. The corrugated structure may comprise a plurality of corrugations or pleats penetrating the HME along a surface of the corrugated structure, the corrugated structure retaining moisture from the exhaled gas flow and providing the retained moisture to the breathable gas flow for humidification. The moisture may include both liquid and vapor forms. The term "corrugations" referred to herein is also commonly referred to as pleats and is used interchangeably. The plurality of corrugations increases the surface area of ​​the corrugated structure within a predetermined size range, thereby enhancing interaction between the surface of the HME and the air exhaled from the patient. This enhances heat and moisture exchange between the patient and the HME, ultimately improving the humidification performance of the HME in the patient interface to a desired level. Improved humidification performance also allows a smaller HME to function at the desired performance level, thereby occupying less volume within the patient interface. The volume occupied by the HME can affect flow impedance, which can affect CO2 outflow and / or result in a loss of therapeutic pressure delivered to the patient during PAP therapy. Therefore, increasing the surface area per unit volume of the corrugated HME material for moisture exchange can reduce the HME's effect on flow impedance. The corrugations also allow more access for the respiratory gas flow to the HME's heat and moisture exchange surface, thereby providing the HME with a high surface area per unit volume that can provide superior humidification to the patient.

[0061] Another aspect of one form of the present technology is an HME, wherein the HME has a plurality of channels defined partially or completely by the corrugations of the HME oriented substantially parallel to the flow path of the breathable gas flow, the channel orientation allowing the breathable gas flow through the HME directly along the surface of the moisture exchange layer, thereby reducing the effect of the HME on flow impedance.

[0062] Another aspect of one form of the present technology is an HME that may further include a generally flat bottom structure, and the corrugated structure may be engaged with the bottom structure to form a layer. The corrugated structure may include upper and lower folded portions, and each lower folded portion may be engaged with the bottom structure. The bottom structure may form a flat support base, in which case the corrugated structure may extend vertically from the bottom structure to form the layer. Alternatively, the layer may further include a generally flat top structure, in which case the corrugated structure is disposed between the top and bottom structures to form a concertina-shaped layer. The HME may be comprised of a single concertina-shaped layer. The top and bottom structures may provide structural support to the corrugated structure and maintain channels formed by the corrugations to allow breathable gas to flow through the HME along the surface of the corrugated structure. The top and / or bottom structures may be formed from a moisture-non-absorbent material. Alternatively, the top and / or bottom structures may be formed from the same material as the corrugated structure. Upper and / or lower structure weight 15-100g / m 2 The thickness of the top and / or bottom structures affects the stiffness of the structure and therefore its ability to provide structural support. However, there is a trade-off between maximizing the thickness of the top and / or bottom structures to provide support and minimizing the thickness to reduce the HME's effect on flow impedance. The overall thickness of the HME is a significant factor that alters the density and surface area per unit volume of the HME. These factors, in turn, affect the overall humidification performance of the HME.

[0063] In another form of the present technology, an HME may be formed from multiple layers that form a predetermined three-dimensional shape adapted to fit within a plenum chamber of a patient interface. Each layer includes a corrugated structure and at least one generally flat supportive lower end structure. Patient interfaces come in a variety of shapes and sizes. Therefore, the HME must adapt to the various internal volumes of the patient interface to fit within the patient interface's inner walls. Forming an HME into a desired three-dimensional shape to fit within a patient interface in the proper orientation is difficult. Furthermore, orienting the HME while maintaining the HME's humidification effectiveness and reducing the HME's effect on flow impedance adds another level of complexity. Generally, materials used in HME manufacturing cannot be molded to yield a desired three-dimensional shape while maintaining the ability to humidify the gas flow. Therefore, forming an HME from multiple layers into a desired three-dimensional shape provides flexibility in shaping the HME while maintaining the HME's humidification performance. The HME of the present technology may be formed by stacking multiple layers. The layers may be stacked vertically along the vertical axis of the HME. By stacking layers of HME material, the HME can be formed into a desired three-dimensional shape, with each layer properly oriented to maximize performance. The channels formed by the corrugated structures in each layer may be aligned substantially perpendicular to the channels of the corrugated structures in adjacent layers to maximize breathable gas flow through the channels for moisture exchange. Each layer may be formed by laser cutting a portion of the layer to form the layer into a predetermined three-dimensional shape. Alternatively, the entire HME may be formed by laser cutting it into a predetermined three-dimensional shape. Layers may be formed from different sizes and / or shapes and combined to form an HME with an overall desired three-dimensional shape. Having layers of different sizes and shapes allows the HME to be formed into an irregular shape to fit within the plenum chamber of a patient interface.

[0064] In other forms of the present technology, the HME may be shaped to avoid contact with the patient's face. The HME may include a portion that curves inward to avoid contact with the patient's nose or mouth. Positioning the HME close to the entrance of the patient's airways maximizes capture of exhaled moisture. However, contact with the patient's face must be avoided or at least minimized to prevent discomfort. Therefore, it is desirable to shape the HME to follow the shape of the patient's face to position the HME close to the entrance of the patient's airways while avoiding or at least minimizing contact with the patient. For example, the HME may be curved to avoid following the shape of the patient's face within the patient interface.

[0065] In another form of the technology, the HME is 4 to 14 m 2 / m 3 The HME is structured to have a predetermined surface area per unit volume. The surface area per unit volume is directly related to the humidification performance of the HME. That is, a high surface area per unit volume can enhance moisture exchange between the HME and the humidification source to capture moisture. An HME with a high surface area per unit volume can also minimize the volume the HME occupies in the plenum chamber. The volume occupied by the HME in the plenum chamber can affect flow impedance, which can affect CO2 outflow and therapeutic pressure delivery to the patient. Therefore, an HME with a high surface area per unit volume can reduce the HME's effect on flow impedance. One way to reduce the surface area per unit volume is to introduce corrugations into the HME. Alternatively, the HME may be formed from multiple layers, each with a corrugated structure. The corrugated structure forms multiple channels and allows breathable gas to flow along the surface of the HME through the channels. In effect, the corrugations and channels increase the surface area per unit volume of the HME.

[0066] In another form of the present technology, the HME is selected to have a water absorption rate of 50-100 mm / 10 min. A faster water absorption rate allows for faster fluid exchange by the HME. This can improve overall fluid uptake by the HME, which can then be re-delivered from the HME to the patient more quickly. The water absorption rate can be altered by varying the amount of HME material available within a given size range. The water absorption rate is also affected by the surface area of ​​the HME available for fluid exchange. Therefore, the HME may be selected to maximize the amount of HME material within a given size range while attempting to maximize the surface area per unit volume of the HME available for fluid exchange. The water absorption rate can also be increased by the addition of biocompatible additives, such as drying additives. For example, CaCl2 may be added to the HME.

[0067] Another aspect of one form of the present technology is directed to an HME structured to have a flow impedance of 0-2.5 cmH2O at a predetermined flow rate of 100 L / min. The flow impedance may be 0-1.6 cmH2O at the predetermined flow rate. The flow rate is the flow rate of breathable gas delivered to the patient interface. The HME includes at least one corrugated structure having a plurality of corrugations, the plurality of corrugations forming a plurality of channels to allow breathable gas flow through the HME along a surface of the corrugated structure. The plurality of channels may reduce the flow impedance of the HME to the breathable gas flow to a predetermined flow impedance level. The plurality of channels may reduce a sheet density of the corrugated structure to a predetermined sheet density to reduce the flow impedance within a predetermined range. The HME has a density of 0.02-0.4 g / cm 3The HME may be structured to have at least one corrugated structure having a predetermined density. Also, blockage may be reduced by increasing the number of channels to a predetermined number. Flow impedance may be reduced within a predetermined range by increasing the pitch of each corrugation or pleat to 1 to 4 mm. Pitch may be understood to mean the width of the channel defined by the corrugation. The pitch of each corrugation or pleat is 1.7 to 3.5 mm. Flow impedance may be reduced within a desired range by increasing the total volume of the multiple channels within the flow path of the breathable gas flow. It may also be advantageous to reduce the flow impedance of the HME for the expiratory gas flow to allow a CO2 outflow level from the patient interface sufficient to prevent significant CO2 inhalation, which may cause respiratory discomfort. However, it is also desirable to maintain the humidification performance of the HME for the breathable gas flow to enhance breathing comfort. Increasing humidification performance to a predetermined level may require minimizing the amount of HME material present within the HME. Therefore, it is desirable to strike a balance between reducing the level of flow impedance to expiratory gas flow caused by the HME and maintaining the humidification performance of the HME.

[0068] Another aspect of one form of the present technology is directed to an HME removably engaging with a patient interface for delivering a flow of breathable gas to an entrance of a patient's airway, including at least the entrances of the patient's nares. The HME may include a rigid frame circumferentially surrounding an outer periphery of the HME, the frame configured to removably engage an inner surface of a plenum chamber of the patient interface to position the HME within a flow path of the flow of breathable gas. The rigid HME frame may provide structural support for the HME and may include a removably engageable portion for engaging within the patient interface. The rigid frame may include at least one engagement member for engaging an inner surface of the plenum chamber of the patient interface. The engagement member may include a clip for engaging the inner surface of the plenum chamber. Alternatively, the engagement member may be in a form selected from the group consisting of an adhesively engageable portion, a clip, an elastic flange, and a hook and loop.

[0069] Another aspect of one form of the present technology is directed to an HME frame further comprising a moisture-retaining reservoir for retaining additional moisture and resupplying it to the HME material of the HME. For example, the reservoir may resupply the retained moisture to a layer of the HME. In addition to moisture retention by the HME, an additional reservoir for retaining moisture may be provided in the frame. For example, a portion of the HME frame may be formed from a moisture-absorbing material. This material may be a high-density sponge. Moisture may be absorbed from the HME by the high-density sponge through capillary action and resupplied to the HME for hydration.

[0070] Another aspect of one form of the present technology is directed to a patient interface for delivering a flow of breathable gas to an entrance of a patient's airways, including at least the entrances of the patient's nares, the patient interface including an HME configured to divide a plenum chamber of the patient interface into a first anterior chamber and a second posterior chamber. The HME may be positioned within the plenum chamber to humidify the flow of breathable gas flowing from the first anterior chamber to the second posterior chamber. The second posterior chamber may include a seal-forming structure for sealing with a portion of the patient's face. The first anterior chamber may include an inlet for receiving the flow of breathable gas into the first anterior chamber and a vent for the exit of the exhaled gas flow from the first anterior chamber. This location of the HME in this form can be beneficial because it allows exhaled gas from the patient to flow through the HME to retain moisture before exiting through the vent. The HME may also be positioned to allow the flow of breathable gas from the inlet to flow through the HME to re-deliver retained moisture to the patient. An additional vent can also be located in the rear plenum chamber to offset CO2 buildup within this volume. For example, in the case of a full-face mask, the additional volume (i.e., dead space volume) in the rear plenum chamber can result in undesirable excessive CO2 buildup within this space compared to a smaller mask. To mitigate this effect, an additional vent can be located near the patient's airway on the rear or patient side of the plenum chamber relative to the HME. Locating a vent on the rear side of the HME can aid in ventilation of the HME-humidified breathable gas flow before delivery to the patient. To compensate for this ventilation of humidified air, overall humidification performance may be maintained by increasing the HME's ability to humidify the breathable gas flow within a given volume of the plenum chamber. The inlet may be adapted to removably engage a conduit for delivering the breathable gas flow to the inlet. The vent may be configured to regulate the outflow of exhaled gas to a substantially constant flow rate. The patient interface may further include a vent adapter comprising a vent and an inlet.The vent adapter may be adapted to removably engage with the remainder of the patient interface to form a plenum chamber. The vent adapter may be removably engaged with the remainder of the patient interface by a resilient clip. A front portion of the vent adapter may form at least one wall of the first anterior chamber. The vent adapter may include a wall forming a housing portion for accommodating the HME. The housing portion may be configured to position the HME within the plenum chamber. The vent adapter may be such that, in use, the vent and inlet are located anteriorly of the HME, while an inlet to the patient's airway may be located posteriorly of the HME. The patient interface may also include a cushion assembly including an opening and a seal-forming structure.

[0071] Another aspect of one form of the present technology is a method of manufacturing an HME for humidifying a flow of breathable gas delivered by a patient interface, the HME having a desired flow impedance, the method comprising: corrugating at least a portion of the HME to form a plurality of channels to allow flow of breathable gas through the HME along surfaces of the corrugated structure; and adjusting the number of corrugations forming the channels to increase the flow rate of the breathable gas through the channels, thereby achieving the desired flow impedance.

[0072] Another aspect of one form of the present technology is a method of manufacturing a patient interface for delivering a flow of breathable gas to an entrance of a patient airway, the patient interface comprising an HME having a desired humidification performance for humidifying the flow of breathable gas. The method may further comprise the steps of manufacturing the patient interface, determining a volume of a plenum chamber of the patient interface for delivering the flow of breathable gas to a patient, corrugating at least a portion of the HME to form a plurality of channels to allow flow of breathable gas along surfaces of the corrugated structure through the HME, adjusting the number of corrugations forming the channels to increase the surface area per unit volume of the HME based on the volume of the plenum chamber to achieve a desired added absolute humidity, and / or removably or permanently securing the HME within the plenum chamber of the patient interface in a flow path of the flow of breathable gas.

[0073] Another aspect of one form of the present technology is a method for manufacturing an HME with an increased surface area per unit volume to obtain a desired humidification performance for humidifying a breathable gas flow, the method may include determining the desired humidification performance, corrugating at least a portion of the HME to form a plurality of channels to allow breathable gas flow along the surface of the corrugated structure through the HME, adjusting the number of corrugations that form the channels to increase the surface area per unit volume of the HME, and / or stacking the HME into corrugated layers to further increase the surface area per unit volume of the HME to obtain the desired humidification performance.

[0074] Another aspect of one form of the present technology is a manufacturing method for increasing the humidification performance of an HME for humidifying a flow of breathable gas delivered by a patient interface to a desired level, the method may include determining a required humidification performance of the HME, laser cutting a plurality of channels through the HME to increase the surface area per unit volume to increase the humidification performance of the HME, and / or increasing the number of channels by laser cutting until the desired humidification performance is achieved.

[0075] Another aspect of one form of the present technology is a patient interface that is molded or otherwise configured with a clearly defined circumferential shape that is adapted to match the circumferential shape of the intended wearer.

[0076] One aspect of one form of the present technology is a portable RPT device that may be carried by a person, for example, around their home.

[0077] An aspect of one form of the present technology is a patient interface that may be cleaned in the patient's home, for example, in soapy water, without the need for specialized cleaning equipment.An aspect of one form of the present technology is a humidifier tank that may be cleaned in the patient's home, for example, in soapy water, without the need for specialized cleaning equipment.

[0078] Of course, some of the aspects may form sub-aspects of the technology, and various of the sub-aspects and / or aspects may be combined in various ways and form further aspects or sub-aspects of the technology.

[0079] Other features of the present technology will become apparent from consideration of the information contained in the following detailed description, abstract, drawings, and claims.

[0080] 4. Brief description of some of the figures in the drawing The present technology is illustrated by way of example, and not by way of limitation, in the following accompanying drawing figures, in which like reference numerals refer to like elements: Figures 1A-2L illustrate a treatment system, Figure 3A illustrates a patient interface, Figures 4A-4E illustrate an RPT device, Figures 5A-5C illustrate a humidifier, Figures 6A-6E illustrate a respiratory waveform, and Figures 7A-17 illustrate a heat and moisture exchanger. [Brief explanation of the drawings]

[0081] [Figure 1A]A system is shown including a patient 1000 wearing a patient interface 3000 in the form of nasal pillows that receives a predetermined amount of air at positive pressure from an RPT device 4000. The air from the RPT device is humidified in a humidifier 5000 and passed along an air circuit 4170 towards the patient 1000. A bed partner 1100 is also shown. [Figure 1B] The system is shown to include a patient 1000 wearing a patient interface 3000 in the form of a nasal mask that receives a predetermined amount of air at positive pressure from an RPT device 4000. The air from the RPT device is humidified in a humidifier 5000 and passed along an air circuit 4170 towards the patient 1000. [Figure 1C] The system is shown to include a patient 1000 wearing a patient interface 3000 in the form of a full face mask that receives a predetermined amount of air at positive pressure from an RPT device 4000. The air from the RPT device is humidified in a humidifier 5000 and passed along an air circuit 4170 towards the patient 1000. [Figure 1D] Shown is a patient 1000 undergoing polysomnography (PSG). 4.2 Respiratory System and Facial Anatomy [Figure 2A] 1 shows a general view of the human respiratory system, including the nasal and oral cavities, larynx, vocal cords, esophagus, trachea, bronchi, lungs, alveolar sacs, heart, and diaphragm. [Figure 2B] 1 shows a diagram of the human upper respiratory tract, including the nasal cavity, nasal bones, lateral nasal cartilages, alar cartilages, nostrils, upper lip, lower lip, larynx, hard palate, soft palate, oropharynx, tongue, epiglottis, vocal cords, esophagus, and trachea. [Figure 2C] FIG. 1 is a front view of a face with several features of the surface anatomy identified, including upper lip, vermilion, lower lip, mouth width, inner corners of the eyes, alae of the nose, nasolabial folds, and corners of the mouth, and also shows the directions of superior, inferior, radially inward, and radially outward. [Figure 2D] A side view of the head with several features of the surface anatomy identified, including the glabella, root of the nose, tip of the nose, nasal spine, upper lip, lower lip, maxilla, nasal ridge, apex of the nasal alar, superior ear base, and inferior ear base. Also shown are the superior and inferior, and anterior and posterior directions. [Figure 2E]1 is a further lateral view of the head, showing the approximate location of the Frankfort plane and the nasolabial angle. The coronal plane is also shown. [Figure 2F] Shown is a bottom view of the nose with several features identified including the nasolabial fold, lower lip, upper lip vermilion, nostrils, subnasal point, columella, tip point, major axis of the nostrils, and sagittal plane. [Figure 2G] 1 shows a side view of the surface features of the nose. [Figure 2H] Shown are the subcutaneous structures of the nose, including the lateral cartilages, nasal septum cartilage, greater alar cartilage, lesser alar cartilage, sesamoid cartilage, nasal bones, epidermis, adipose tissue, frontal process of the maxilla, and fibroadipose tissue. [Figure 2I] There is a medial nasal detachment of approximately a few millimeters from the sagittal plane, particularly showing the septal cartilage and the medial crus of the greater alar cartilage. [Figure 2J] 1 shows a frontal view of the bones of the skull, including the frontal, nasal, and cheekbones. The nasal turbinates are shown, as well as the maxilla and mandible. [Figure 2K] Shows a lateral view of the skull with the surface outline of the head and some muscles. The following bones are shown: frontal, sphenoid, nasal, zygomatic, maxilla, mandible, parietal, temporal, and occipital. The mental protuberance is shown. The following muscles are shown: digastric, masseter, sternocleidomastoid, and trapezius. [Figure 2L] An anterolateral view of the nose is shown. [Figure 3A] 14 shows a patient interface in the form of a nasal mask in accordance with one form of the present technology. [Figure 4A] 1 shows an RPT device in accordance with one form of the present technology. [Figure 4B]

[0023] Fig. 11 shows a schematic diagram of the pneumatic paths of an RPT device in accordance with one form of the present technology, with upstream and downstream directions indicated. [Figure 4C] FIG. 1 shows a schematic diagram of the electrical components of an RPT device in accordance with one aspect of the present technology. [Figure 4D] 1 shows a schematic diagram of an algorithm implemented in an RPT device according to one aspect of the present technology, in which solid arrows indicate the actual flow of information, e.g., via electronic signals. [Figure 4E]4d is a flowchart illustrating a method performed by the therapy engine module of FIG. 4d in accordance with one aspect of the present technology. [Figure 5A]

[0023] Fig. 1 shows a schematic diagram of a humidifier in accordance with one aspect of the present technology. [Figure 5B] FIG. 10 shows an isometric view of a humidifier in accordance with one aspect of the present technology, showing the humidifier reservoir 5110 removed from the humidifier reservoir dock 5130. [Figure 5C]

[0023] Fig. 1 shows a schematic diagram of a humidifier in accordance with one aspect of the present technology. [Figure 6A] 1 shows a model of a typical breathing waveform of a sleeping person. [Figure 6B] A patient is shown in non-REM sleep breathing normally for a period of approximately 90 seconds. [Figure 6C] 1 shows a polysomnogram of a patient before treatment. [Figure 6D] 1 shows patient flow data as the patient experiences a series of total obstructive apneas. [Figure 6E] 1 shows the scaled inspiratory portion of a breath when the patient is experiencing low frequency inspiratory snoring. [Figure 7A] FIG. 7 shows a cross-sectional view of a HME 7000 with a single layer 7001 according to one aspect of the present technology. [Figure 7B] 1 shows an example of a single waveform section 7030 of an HME 7000 in accordance with one aspect of the present technology. [Figure 7C] FIG. 7 is a schematic diagram showing an HME 7000 comprising multiple layers 7001 stacked along both vertical and horizontal axes. [Figure 7D] FIG. 7 shows an HME that is preloaded to compress the corrugations within a predetermined volume such that the number of layers 7001 is increased within a predetermined size range. [Figure 8A] A corrugated structure 7002 is shown comprising a plurality of corrugations 7030, where the corrugated structure is rolled to form the HME 7000. [Figure 8B] 1 shows an example of a patient interface 3000 with an HME 7000 positioned within a plenum chamber 3200 in accordance with the present technology. [Figure 8C]1 shows an example of a patient interface 3000 with an HME 7000 positioned within a plenum chamber 3200 in accordance with the present technology. [Figure 8D] 1 shows an example of a patient interface 3000 with an HME 7000 positioned within a plenum chamber 3200 in accordance with the present technology. [Figure 9A]

[0033] Fig. 13 shows an exploded view of another patient interface 3000 with an HME 7000 housed within a vent adapter 3410 in accordance with the present technology. [Figure 9B]

[0033] Fig. 13 shows an exploded view of another patient interface 3000 with an HME 7000 housed within a vent adapter 3410 in accordance with the present technology. [Figure 9C] 10 shows a top view of a further example of a patient interface 3000 in accordance with the present technology. [Figure 9D] 10 shows a perspective view of a further example of a patient interface 3000 in accordance with the present technology. [Figure 9E] 10 shows a rear view of a further example of a patient interface 3000 in accordance with the present technology. [Figure 9F] 10 shows a side view of a further example of a patient interface 3000 in accordance with the present technology. [Figure 9G] 30 shows a bottom view of a further example of a patient interface 3000 in accordance with the present technology. [Figure 9H] 10 shows a bottom perspective view of a further example of a patient interface 3000 in accordance with the present technology. [Figure 9I] 10 shows a bottom perspective view of a further example of a patient interface 3000 in accordance with the present technology. [Figure 9J] FIG. 9J shows a cross-sectional view of a further example of a patient interface 3000 taken through line 9J-9J of FIG. 9I in accordance with the present technology. [Figure 10A] A front view of the HME frame 7003 of the removable HME 7000 is shown. [Figure 10B] A rear view of the HME frame 7003 of the removable HME 7000 is shown. [Figure 10C] A side view of the HME frame 7003 of the removable HME 7000 is shown. [Figure 10D]A bottom view of the HME frame 7003 of the removable HME 7000 is shown. [Figure 10E] A first perspective view of the HME frame 7003 of the removable HME 7000 is shown. [Figure 10F] A second perspective view of the HME frame 7003 of the removable HME 7000 is shown. [Figure 11A] 7 shows a further example removable HME 7000 in which a close-up view of layer 7001 is shown. [Figure 11B] A front view of the detachable HME7000 is shown. [Figure 11C] A rear view of the detachable HME7000 is shown. [Figure 11D] A side view of the detachable HME7000 is shown. [Figure 11E] A bottom view of the detachable HME7000 is shown. [Figure 11F] FIG. 7I shows a first perspective view of the removable HME 7000. [Figure 11G] FIG. 7I shows a second perspective view of the removable HME 7000 of FIG. [Figure 12A] A front perspective view of the HME housing portion 3410 of the patient interface 3000 is shown. [Figure 12B] A rear perspective view of the HME housing portion 3410 of the patient interface 3000 is shown. [Figure 12C] A top perspective view of the HME housing portion 3410 of the patient interface 3000 is shown. [Figure 12D] A rear view of the HME housing portion 3410 of the patient interface 3000 is shown. [Figure 13A] 1 shows a flow diagram of a typical process that may be followed to select an appropriate heat and moisture exchanger (HME or HMX). [Figure 13B] 1 shows a chart of humidified lung weight loss with various types of humidification. [Figure 13C] 10A-10C illustrate various examples of corrugation or pleat configurations that form corrugated structures that may be utilized in HMEs in accordance with embodiments of the present technology. [Figure 13D] 1 illustrates various exemplary corrugation structure parameters according to embodiments of the present technology; [Figure 13E] The measurements used to provide the parameters listed in the chart of Figure 13D are shown. [Figure 14A]

[0033] Fig. 14 shows a rear view of a patient interface with an HME in accordance with an example of the present technology. [Figure 14B]

[0033] Fig. 14 shows a front perspective view of a patient interface with an HME according to an example of the present technology. [Figure 14C]

[0033] Fig. 14 shows a front perspective view of a patient interface with a HME and supporting membrane according to an example of the present technology. [Figure 14D]

[0033] Fig. 14 shows a front view of a patient interface with an HME in accordance with an example of the present technology. [Figure 14E]

[0033] Fig. 14 shows a front view of a patient interface with a HME and supporting membrane in accordance with an example of the present technology. [Figure 14F]

[0033] Fig. 14 shows a side view of a patient interface with an HME worn by a patient in accordance with an example of the present technology. [Figure 15A]

[0033] Fig. 14 shows a side view of a patient interface with an HME worn by a patient in accordance with an example of the present technology. [Figure 15B]

[0033] Fig. 14 shows a front view of a patient interface with an HME in accordance with an example of the present technology. [Figure 15C]

[0033] Fig. 14 shows a rear view of a patient interface with a HME and supporting membrane in accordance with an example of the present technology. [Figure 16]

[0033] Fig. 11 shows a rear view of a HME and supporting membrane according to an example of the present technology. [Figure 17] 1 is a graph comparing the humidity added above ambient humidity at different treatment pressures and flow rates when the HME is placed within a known mask (ResMed Quattro FX). DETAILED DESCRIPTION OF THE INVENTION

[0082] 5 Detailed Description of the Embodiments of the Present Technology Before describing the present technology in further detail, it is to be understood that the present technology is not limited to the specific embodiments, which may vary, described herein. It is also to be understood that the terminology used in this disclosure is for the purpose of describing only the specific embodiments discussed herein, and is not intended to be limiting.

[0083] The following description is provided in connection with various embodiments that may share one or more common characteristics and / or features. It should be understood that one or more features of any one embodiment may be combined with one or more features of another embodiment or embodiments. Also, any single feature or combination of features in any embodiment may constitute an additional embodiment.

[0084] 5.1 Treatment In one form, the present technology comprises a method for treating a respiratory disorder comprising applying positive pressure to an entrance to the airways of a patient 1000.

[0085] In certain embodiments of the present technology, a predetermined amount of air at positive pressure is delivered to a patient's nasal passages via one or both nostrils.

[0086] In certain embodiments of the present technology, mouth breathing is restricted, limited, or prevented.

[0087] 5.2 Treatment System In one form, the present technology comprises an apparatus or device for treating a respiratory disorder. The apparatus or device may comprise an RPT device 4000 for supplying pressurized respiratory gas, such as air, to a patient 1000 via an air circuit 4170 leading to a patient interface 3000.

[0088] 5.3 Patient Interface A non-invasive patient interface 3000 in accordance with one aspect of the present technology comprises the following functional aspects: a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilising structure 3300, and one form of a connection port 3600 for connection to an air circuit 4170. In some forms, the functional aspects may be provided by one or more physical components. In some forms, a single physical component may provide one or more functional aspects. In use, the seal-forming structure 3100 is positioned to surround an entrance to the patient's airways to facilitate the delivery of air at positive pressure to the airways.

[0089] 5.3.1 Seal-forming structure In one form of the present technology, the seal-forming structure 3100 provides a seal-forming surface and may also provide a cushioning function.

[0090] The seal-forming structure 3100 in accordance with the present technology may be constructed from a soft, flexible, resilient material such as silicone.

[0091] In one form, the seal-forming structure 3100 comprises a sealing flange 3110 and a support flange 3120. The sealing flange 3110 may comprise a relatively thin member having a thickness of less than about 1 mm, for example, about 0.25 mm to about 0.45 mm, extending around the outer periphery 3210 of the plenum chamber 3200. The support flange 3120 may be relatively thicker than the sealing flange 3110. The support flange 3120 is disposed between the sealing flange 3110 and the periphery 3220 of the plenum chamber 3200 and extends around at least a portion of the path of the outer periphery 3210. The support flange 3120 is or includes a spring-like element that functions to support the sealing flange 3110 against buckling during use. During use, the sealing flange 3110 is responsive to system pressure within the plenum chamber 3200 acting on an underside of the sealing flange to urge the sealing flange into tight sealing engagement with the face.

[0092] In one form, the seal-forming portion of the non-invasive patient interface 3000 comprises a pair of nasal puffs or a pair of nasal pillows, each nasal puff or nasal pillow constructed and arranged to form a seal with a respective nostril of the patient's nose.

[0093] Nasal pillows according to one aspect of the present technology include a truncated cone, at least a portion of which forms a seal with the underside of a patient's nose, a stem, and a flexible region on the underside of the truncated cone that connects the truncated cone to the stem. Additionally, the structure to which the nasal pillows of the present technology are connected includes a flexible region adjacent to the base of the stem. The flexible regions may cooperate to facilitate a universal joint structure that accommodates relative movement—both displacement and tilt—between the truncated cone and the structure to which the nasal pillows are connected. For example, the truncated cone may be moved axially toward the structure to which the stem is connected.

[0094] In one form, the non-invasive patient interface 3000 comprises a seal-forming portion that, in use, forms a seal with the patient's face in the upper lip region (ie, upper lip).

[0095] In one form, the non-invasive patient interface 3000 comprises a seal-forming portion that, in use, forms a seal with the chin region of the patient's face.

[0096] 5.3.2 Plenum chamber The plenum chamber 3200 has a perimeter 3210 that is shaped to be complimentary to the surface contours of an average human face in the area where a seal will occur in use. In use, the perimeter 3220 of the plenum chamber 3200 is positioned in close proximity to the adjacent surface of the face. Actual contact with the face is provided by the seal-forming structure 3100. The seal-forming structure 3100 may extend around the entire perimeter 3210 of the plenum chamber 3200 in use.

[0097] 5.3.3 Positioning and stabilising structures The seal-forming portion 3100 of the patient interface 3000 of the present technology is held in a sealing position by a positioning and stabilising structure 3300 in use.

[0098] 5.3.4 Venting In one form, the patient interface 3000 includes a vent 3400 constructed and arranged to allow the exit of exhaled carbon dioxide.

[0099] One form of a vent 3400 according to the present technology comprises a plurality of holes, for example, about 20 to about 80 holes, or about 40 to about 60 holes, or about 45 to about 55 holes.

[0100] The vent 3400 is located in the plenum chamber 3200. Alternatively, the vent 3400 is located in a tube separation structure 3500, such as a swivel 3510.

[0101] 5.3.5 Separate structures In one form, the patient interface 3000 includes at least one tube decoupling structure 3500, such as a swivel 3510 or a ball and socket 3520.

[0102] 5.3.6 Connection Port A connection port 3600 allows connection to the air circuit 4170 .

[0103] 5.3.7 Frontal support In one form, the patient interface 3000 includes a forehead support 3700 .

[0104] 5.3.8 Anti-asphyxiation valve In one form, the patient interface 3000 includes an anti-asphyxiation valve 3800 .

[0105] 5.3.9 Ports In one form of the present technology, the patient interface 3000 includes one or more ports that allow access to the volume within the plenum chamber 3200. In one form, this allows a physician to provide supplemental oxygen. In one form, this allows direct measurement of properties of the gas within the plenum chamber 3200, such as pressure.

[0106] 5.4 RPT device In accordance with one aspect of the present technology, an RPT device 4000 includes mechanical and pneumatic components 4100 and electrical components 4200 and is configured to execute one or more algorithms 4300. The RPT device may have an outer housing 4010, which may be formed in two parts, i.e., an upper portion 4012 and a lower portion 4014. The outer housing 4010 may also include one or more panels 4015. The RPT device 4000 includes a housing 4016 that supports one or more internal components of the RPT device 4000. The RPT device 4000 may include a handle 4018.

[0107] The air pressure path of the RPT device 4000 may include one or more air path components, such as an inlet air filter 4112, an inlet muffler 4122, a pressure generator 4140 (e.g., a blower 4142) capable of supplying air at positive pressure, an outlet muffler 4124, and one or more transducers 4270, such as a pressure sensor 4272 and a flow sensor 4274.

[0108] One or more of the air path components may be located within a removable, unitary structure referred to as a pneumatic block 4020. The pneumatic block 4020 may be located within the outer housing 4010. In one form, the pneumatic block 4020 is supported by or formed as part of a portion of the housing 4016.

[0109] The RPT device 4000 may include a power supply 4210, one or more input devices 4220, a central controller 4230, a therapy device controller 4240, a pressure generator 4140, one or more protection circuits 4250, a memory 4260, a transducer 4270, a data communication interface 4280, and one or more output devices 4290. The electrical components 4200 may be mounted on a single printed circuit board assembly (PCBA) 4202. In another form, the RPT device 4000 may include multiple PCBAs 4202.

[0110] 5.4.1 Mechanical and pneumatic components of RPT devices The RPT device may comprise one or more of the following components in an integral unit: Alternatively, one or more of the following components may be located as respective separate units:

[0111] 5.4.1.1 Air filters An RPT device in accordance with one form of the present technology may include one air filter 4110 or multiple air filters 4110.

[0112] In one form, an inlet air filter 4112 is located at the beginning of the air pressure path upstream of the pressure generator 4140. See Figure 4B.

[0113] In one form, an outlet air filter 4114, for example an antibacterial filter, is located between the outlet of the pneumatic block 4020 and the patient interface 3000. See Figure 4B.

[0114] 5.4.1.2 Muffler In one form of the present technology, an inlet muffler 4122 is positioned in the air pressure path upstream of a pressure generator 4140. See Figure 4B.

[0115] In one form of the present technology, an outlet muffler 4124 is located in the pneumatic path between the pressure generator 4140 and the patient interface 3000. See Figure 4B.

[0116] 5.4.1.3 Pressure generator In one form of the present technology, the pressure generator 4140 for generating the flow or supply of air at positive pressure is a controllable blower 4142. For example, the blower 4142 may include a brushless DC motor 4144 having one or more impellers housed in a volute. The blower may be capable of delivering a volume of air at a positive pressure in the range of about 4 cmH2O to about 20 cmH2O, or in other forms up to about 30 cmH2O, at a rate of, for example, up to about 120 liters / minute. Blowers are described in any one of the following patents or patent applications: U.S. Patent No. 7,866,944; U.S. Patent No. 8,638,014; U.S. Patent No. 8,636,479; and PCT International Patent Application Publication No. 2013 / 020167, the contents of which are incorporated herein in their entireties.

[0117] The pressure generator 4140 is under the control of the therapy device controller 4240 .

[0118] In one form, pressure generator 4140 may be a piston-driven pump, a pressure regulator connected to a high pressure source (eg, a compressed air reservoir), or a bellows.

[0119] 5.4.1.4 Transducers The transducer may be internal to the RPT device or external to the RPT device. An external transducer may, for example, be located in or form part of the air circuit, e.g., the patient interface. An external transducer may take the form of a non-contact sensor, such as a Doppler radar motion sensor, that transmits or communicates data to the RPT device.

[0120] In one form of the present technology, 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 measure a property of that point in the pneumatic path, such as flow rate, pressure, or temperature.

[0121] In one form of the present technology, one or more transducers 4270 may be positioned proximate to the patient interface 3000.

[0122] In one form, the signal from the transducer 4270 may be filtered, such as by low-pass filtering, high-pass filtering, or band-pass filtering.

[0123] 5.4.1.4.1 Flow Transducers The flow transducer 4274 in accordance with the present technology may be based on a differential pressure transducer, such as the SDP600 series differential pressure transducers offered by SENSIRION.

[0124] In one form, a signal representing a flow rate, such as total flow rate Qt, from the flow transducer 4274 is received by the central controller 4230.

[0125] 5.4.1.4.2 Pressure Transducers A pressure transducer 4272 according to the present technology is positioned in fluid communication with the pneumatic path. One example of a suitable pressure transducer is a sensor from the HONEYWELL ASDX series. Another suitable pressure transducer is a sensor from the NPA series offered by GENERAL ELECTRIC.

[0126] In one form, the signal from the pressure transducer 4272 is received by the central controller 4230 .

[0127] 5.4.1.4.3 Motor Speed ​​Transducers In one form of the present technology, a motor speed transducer 4276 is used to determine the rotational speed of the motor 4144 and / or blower 4142. A motor speed signal from the motor speed transducer 4276 may be provided to the therapy device controller 4240. The motor speed transducer 4276 may be, for example, a speed sensor such as a Hall effect sensor.

[0128] 5.4.1.5 Check valve In one form of the present technology, a non-return valve is located between the humidifier 5000 and the pneumatic block 4020. The non-return valve is constructed and arranged to reduce the risk of water flowing upstream from the humidifier 5000, for example towards the motor 4144.

[0129] 5.4.1.6 Air Circuit The air circuit 4170 according to one aspect of the present technology is a conduit or tube constructed and arranged to allow air flow to travel between two components, such as the pneumatic block 4020 and the patient interface 3000, in use.

[0130] In particular, the air circuit 4170 may be fluidly connected to the outlet of the pneumatic block and the patient interface. The air circuit may also be referred to as an air delivery tube. In some cases, there may be separate limbs of the circuit for inhalation and exhalation. In other cases, a single limb is used.

[0131] 5.4.1.7 Oxygen delivery In one form of the present technology, supplemental oxygen 4180 is delivered to one or more points in the pneumatic path, such as upstream of the pneumatic block 4020, to the pneumatic circuit 4170, and / or to the patient interface 3000.

[0132] 5.4.2 RPT Device Electrical Components 5.4.2.1 Power supply The power supply 4210 may be located inside or outside the external housing 4010 of the RPT device 4000 .

[0133] In one form of the present technology, the power supply 4210 provides power only to the RPT device 4000. In another form of the present technology, the power supply 4210 provides power to both the RPT device 4000 and the humidifier 5000.

[0134] 5.4.2.2 Input Devices In one form of the present technology, the 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 may be 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 in other forms may be in wireless communication with a receiver that is in electrical connection to the central controller 4230.

[0135] In one form, the input device 4220 may be constructed and arranged to allow a person to select values ​​and / or menu options.

[0136] 5.4.2.3 Central Controller In one form of the present technology, the central controller 4230 is one or more processors suitable for controlling the RPT device 4000.

[0137] Suitable processors may include x86 INTEL processors, processors based on ARM Cortex-M processors offered by ARM Holdings, such as the STM32 series microcontrollers offered by ST MICROELECTRONIC, etc. In certain alternative forms of the present technology, 32-bit RISC CPUs such as the STR9 series microcontrollers offered by ST MICROELECTRONICS, or 16-bit RISC CPUs such as processors from the MSP430 family of microcontrollers manufactured by TEXAS INSTRUMENTS may also be suitable.

[0138] In one form of the present technology, the central controller 4230 is a dedicated electronic circuit.

[0139] In one form, the central controller 4230 is an application specific integrated circuit. In another form, the central controller 4230 comprises separate electronic components.

[0140] The central controller 4230 may be configured to receive input signals from one or more transducers 4270 and one or more input devices 4220 .

[0141] The central controller 4230 may be configured to provide output signals to one or more of the output device 4290, the therapy device controller 4240, the data communication interface 4280, and the humidifier controller 5250.

[0142] In some forms of the present technology, the central controller 4230 is configured to implement one or more methodologies described herein, such as one or more algorithms 4300 represented as a computer program stored on a non-transitory computer-readable storage medium such as the memory 4260. In some forms of the present technology, the central controller 4230 may be integrated with the 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 ventilation device or detect respiration-related events by analysis of stored data from, for example, any of the sensors described herein.

[0143] 5.4.2.4 Clock The RPT device 4000 may include a clock 4232 connected to the central controller 4230 .

[0144] 5.4.2.5 Therapy Device Controller In one form of the present technology, the therapy device controller 4240 is a control module 4330 that forms part of the algorithm 4300 executed by the central controller 4230 .

[0145] In one form of the present technology, the therapy device controller 4240 is a dedicated motor control integrated circuit, for example, in one form the MC33035 brushless DC motor controller manufactured by ONSEMI is used.

[0146] 5.4.2.6 Protection circuit The one or more protection circuits 4250 in accordance with the present technology may include electrical protection circuits, temperature and / or pressure safety circuits.

[0147] 5.4.2.7 Memory In accordance with one form of the present technology, the RPT device 4000 includes memory 4260, such as non-volatile memory. In some forms, the memory 4260 may include battery-powered static RAM. In some forms, the memory 4260 may include volatile RAM.

[0148] Memory 4260 may be located on PCBA 4202. Memory 4260 may be in the form of EEPROM or NAND flash.

[0149] Additionally or alternatively, the RPT device 4000 includes a removable form of memory 4260, such as a memory card formed in accordance with the Secure Digital (SD) standard.

[0150] In one form of the present technology, the memory 4260 acts as a non-transitory computer-readable storage medium on which are stored computer program instructions representing one or more methodologies described herein, such as one or more algorithms 4300.

[0151] 5.4.2.8 Data communication systems In one form of the present technology, a data communications interface 4280 is provided and connected to the central controller 4230. The data communications interface 4280 may be connectable to a remote external communications network 4282 and / or a local external communications network 4284. The remote external communications network 4282 may be connectable to a remote external device 4286. The local external communications network 4284 may be connectable to a local external device 4288.

[0152] In one form, the data communication interface 4280 is part of the central controller 4230. In another form, the data communication interface 4280 is separate from the central controller 4230 and may comprise an integrated circuit or processor.

[0153] In one form, the remote external communications network 4282 is the Internet. The data communications interface 4280 may use wired communications (e.g., Ethernet or fiber optic) or wireless protocols (e.g., CDMA, GSM, LTE) to connect to the Internet.

[0154] In one form, the local external communications network 4284 utilizes one or more communications standards such as Bluetooth or consumer infrared protocols.

[0155] In one form, the remote external device 4286 is one or more computers, such as a group of networked computers. In one form, the remote external device 4286 may be a virtual computer rather than a physical computer. In either case, such a remote external device 4286 may be accessible to an appropriately authorized person, such as a physician.

[0156] The local external device 4288 may be a personal computer, a mobile phone, a tablet, or a remote control.

[0157] 5.4.2.9 Output devices, including optional displays and alarms The output device 4290 of the present technology may take the form of one or more of a visual unit, an audio unit, and a tactile unit. The visual display may be a liquid crystal display (LCD) or a light emitting diode (LED) display.

[0158] 5.4.2.9.1 Display Driver The display driver 4292 receives as input characters, symbols or images to be displayed on the display 4294 and converts them into commands that cause the display 4294 to display those characters, symbols or images.

[0159] 5.4.2.9.2 Display Display 4294 is configured to visually display characters, symbols, or images in response to commands received from display driver 4292. For example, display 4294 may be an eight-segment display, in which case display driver 4292 converts each character or symbol, such as the digit "0," into eight logic signals indicating whether each of the eight segments is activated to display a particular character or symbol.

[0160] 5.4.3 RPT Device Algorithm 5.4.3.1 Preprocessing Module A pre-processing module 4310 according to one form of the present technology receives signals as inputs from a transducer 4270, such as a flow transducer 4274 or a pressure transducer 4272, and performs one or more process steps to calculate one or more output values ​​that are used as inputs to other modules, such as a therapy engine module 4320.

[0161] In one form of the present technology, the output values ​​include interface or mask pressure Pm, respiratory flow Qr, and unintentional leak flow Ql.

[0162] In various forms of the present technology, the pre-processing module 4310 comprises one or more of the following algorithms: pressure compensation 4312, vent flow 4314 (e.g., intended leak), leak flow 4316 (e.g., unintentional leak), and respiratory flow 4318.

[0163] 5.4.3.1.1 Pressure compensation In one form of the present technology, a pressure compensation algorithm 4312 receives as an input a signal indicative of the pressure in the pneumatic path near the outlet of the pneumatic block. The pressure compensation algorithm 4312 estimates the pressure drop through the pneumatic circuit 4170 and provides as an output the estimated pressure Pm in the patient interface 3000.

[0164] 5.4.3.1.2 Vent flow rate In one form of the present technology, a vent flow calculation algorithm 4314 takes as input an estimated pressure Pm within the patient interface 3000 and estimates the vent flow Qv of air from the vents 3400 in the patient interface 3000.

[0165] 5.4.3.1.3 Leakage flow rate In one form of the present technology, the leak flow algorithm 4316 receives as input the total flow Qt and the vent flow Qv and provides as output an estimate of the unintentional leak, i.e., the leak flow Ql, by calculating the average of the difference between the total flow Qt and the vent flow Qv over a period long enough to include several respiratory cycles, for example about 10 seconds.

[0166] In one form, the leak flow algorithm 4316 receives as inputs the total flow Qt, the vent flow Qv, and the estimated pressure Pm in the patient interface 3000, and provides as output the leak flow Ql by calculating the leak conductance to determine the leak flow Ql as a function of the leak conductance and the pressure Pm. The leak conductance may be calculated as the quotient of a low pass filtered unvented flow equal to the difference between the total flow Qt and the vent flow Qv and a low pass filtered square root of the pressure Pm, where the low pass filter time constant has a value long enough to include several respiratory cycles, for example about 10 seconds.

[0167] 5.4.3.1.4 Respiratory flow rate In one form of the present technology, the respiratory flow algorithm 4318 receives as inputs the total flow Qt, the vent flow Qv, and the leak flow Ql, and estimates the respiratory flow Qr of air going to the patient by subtracting the vent flow Qv and the leak flow Ql from the total flow Qt.

[0168] 5.4.3.2 Treatment Engine Module In one form of the present technology, the therapy engine module 4320 receives as input one or more of the pressure Pm in the patient interface 3000 and the respiratory flow of air towards the patient and provides one or more therapy parameters as output.

[0169] In one form of the present technology, the treatment parameter is a continuous positive airway pressure (CPAP) treatment pressure, Pt.

[0170] In one form of the present technology, the therapy parameters are one or more of a level of pressure support and a target ventilation.

[0171] In various embodiments, the therapy engine module 4320 comprises one or more of the following algorithms: phase determination 4321, waveform determination 4322, ventilation determination 4323, inspiratory flow limit determination 4324, apnea / hypopnea determination 4325, snoring determination 4326, airway patency determination 4327, and therapy parameter determination 4328.

[0172] 5.4.3.2.1 Phase determination In one form of the present technology, the RPT device 4000 does not determine the phase.

[0173] In one form of the present technology, a phase determination algorithm 4321 receives as input a signal indicative of respiratory flow Qr and provides as output the phase Φ of the patient's 1000 respiratory cycle.

[0174] In one form, the phase output is a discrete variable that varies with the value of either inspiration or expiration. In one implementation of this form, phase Φ is determined to have a discrete value of inspiration when respiratory flow Qr has a positive value that exceeds a positive threshold, and phase Φ is determined to have a discrete value of expiration when respiratory flow Qr has a negative value that is greater than a negative threshold. By convention in this implementation, the phase value during inspiration may be set to 0, while the phase value during inspiration may be set to 1.

[0175] In one form, the phase output is a discrete variable that varies with the value of one of inspiration, mid-inspiration pause, and expiration.

[0176] In one form, the phase output is a continuous variable, for example varying from 0 to 1 or from 0 to 2π radians.

[0177] 5.4.3.2.2 Waveform determination In one form of the present technology, the therapy engine module 4320 provides a substantially constant therapy pressure throughout the patient's breathing cycle.

[0178] In one form of the present technology, the therapy engine module 4320 provides a therapy pressure that varies over the respiratory cycle according to a pressure versus phase waveform.

[0179] In one form of the present technology, the waveform determination algorithm 4322 provides as an output the pressure-phase waveform P(Φ), which may take on values ​​between 0 and 1.

[0180] The predetermined waveform P(Φ) may be provided as a look-up table of values ​​P as a function of phase value Φ, or alternatively, the predetermined waveform P(Φ) may be provided as one or more parameters that characterize the waveform P(Φ) according to a predetermined parametric description.

[0181] In one form, the waveform is maintained at a substantially constant level for all values ​​of phase.

[0182] In one form, the waveform is a square wave with a constant high value for some values ​​of phase and a constant low value for other values ​​of phase, in this form the parameter returned may be a phase threshold above which the waveform rises from a low level to a high level.

[0183] In one form, the waveform P(Φ) has two exponential sections: an exponential increase according to one time constant in phase values ​​up to a threshold, and an exponential decrease in phase values ​​above the threshold. In this form, the returned parameters may be the two time constants and the threshold.

[0184] 5.4.3.2.3 Ventilation determination In one form of the present technology, a ventilation determination algorithm 4323 receives respiratory flow Qr as input and determines an index indicative of patient ventilation Vent.

[0185] In one form, the ventilation determination algorithm 4323 determines the current value of the patient ventilation, Vent, as half the low-pass filtered absolute value of the respiratory flow, Qr.

[0186] 5.4.3.2.4 Determining inspiratory flow limitations In one form of the present technology, a central controller 4230 executes one or more algorithms 4324 for the detection of inspiratory flow limitation.

[0187] In one form, the algorithm 4324 receives as input the respiratory flow signal Qr and provides as output an indication of the extent to which the inspiratory portion of the breath is inspiratory flow limited.

[0188] In one form of this technology, the inspiration portion of each breath is identified by a zero-crossing detector. A number of equally spaced points (e.g., 65 points) representing time points are interpolated along the inspiration flow-time curve for each breath by an interpolator. The curve described by the points is then scaled by a scaler to have a length (duration / period) and area of ​​1 to remove the effects of changes in breathing rate and depth. The scaled breath is then compared in a comparator to a pre-stored template representing a normal, non-obstructive breath similar to the inspiration portion of the breath shown in FIG. 6A. Breaths that deviate from this template by more than a certain threshold (typically 1 scale unit) at any time during inspiration, such as breaths due to coughs, sighs, swallows, and hiccups as determined by the test element, are rejected. For data that is not rejected, a running average of the first such scaled point is calculated by the central controller 4230 over the previous several inspiration events. This is repeated for the second such point, and so on, over the same inspiration event. Thus, for example, 65 scaled data points may be provided by the central controller 4230 and represent a moving average of several previous inspiratory events, e.g., three events. This moving average of continuously updated values ​​of (e.g., 65) points is referred to as the "scaled flow rate," hereinafter denoted as Qs(t). Alternatively, a single inspiratory event may be utilized rather than a moving average.

[0189] From the scale flow rate, two shape factors may be formed that are relevant to determining partial blockage.

[0190] A shape factor of 1 is the ratio of the average of the middle (e.g., 32) scale flow points to the average whole (e.g., 65) scale flow points. If this ratio exceeds 1, the breath is interpreted as normal. If the ratio is less than or equal to 1, the breath is interpreted as obstructed. A ratio of approximately 1.17 is interpreted as the threshold between partially obstructed and non-obstructed breathing, and equates to an adequate degree of obstruction that allows for the maintenance of adequate oxygenation in a typical user.

[0191] Shape factor 2 is calculated as the RMS deviation from unit scale flow taken over an intermediate (e.g., 32) point. An RMS deviation of approximately 0.2 units is interpreted as normal. An RMS deviation of zero is interpreted as a totally flow-limited breath. The closer the RMS deviation is to zero, the more flow-limited the breath is interpreted to be.

[0192] Shape factors 1 and 2 may be used alternatively or in combination. In other forms of the present technology, the number of sampled points, number of breaths, and number of intermediate points may be different from those previously described, and the thresholds may be other than those previously described.

[0193] 5.4.3.2.5 Apnea and hypopnea determination In one form of the present technology, a central controller 4230 executes one or more algorithms 4325 for determining the presence of apnea / hypopnea.

[0194] One or more algorithms 4325 may receive the respiratory flow signal Qr as an input and provide as an output a flag indicating that an apnea or hypopnea has been detected.

[0195] In one form, apnea is said to be detected when a function of respiratory flow Qr falls below a flow threshold for a predetermined period of time. The function may determine peak flow, a relatively short-term average flow, or a flow intermediate between the relatively short-term average flow and the peak flow, e.g., RMS flow. The flow threshold may be a relatively long-term measure of flow.

[0196] In one form, hypopnea is said to be detected when a function of respiratory flow Qr falls below a second flow threshold for a predetermined period of time. The function may determine peak flow, a relatively short-term average flow, or a flow intermediate the relatively short-term average and peak flow, e.g., RMS flow. The second flow threshold may be a relatively long-term indicator of flow. The second flow threshold is greater than the flow threshold used to detect apnea.

[0197] 5.4.3.2.6 Snoring Determination In one form of the present technology, a central controller 4230 executes one or more snore algorithms 4326 for the detection of snoring.

[0198] In one form, the snore algorithm 4326 receives as an input the respiratory flow signal Qr and provides as an output an indication of the degree to which snoring is present.

[0199] Algorithm 4326 may include determining the strength of the flow signal within the range of 30-300 Hz. Algorithm 4326 may also include filtering the respiratory flow signal Qr to reduce background noise, for example the sound of airflow in the system from a blower.

[0200] 5.4.3.2.7 Determining Airway Patency In one form of the present technology, a central controller 4230 executes one or more algorithms 4327 for determining airway patency.

[0201] In one form, the airway patency algorithm 4327 receives as input the respiratory flow signal Qr and determines the power of the signal within a frequency range of about 0.75 Hz to about 3 Hz. The presence of a peak within this frequency range is interpreted as indicating an open airway. The absence of a peak is interpreted as being indicative of a closed airway.

[0202] In one form, the frequency range in which the peak is sought is the frequency of a small forced oscillation at the treatment pressure Pt. In one implementation, the forced oscillation has a frequency of 2 Hz with an amplitude of about 1 cmH2O.

[0203] In one form, the airway patency algorithm 4327 receives the respiratory flow signal Qr as an input and determines the presence or absence of a cardiogenic signal, the absence of which is interpreted as an indication of a closed airway.

[0204] 5.4.3.2.8 Determining Treatment Parameters In one form of the present technology, the central controller 4230 executes one or more algorithms 4328 for the determination of one or more treatment parameters using values ​​returned by one or more of the other algorithms in the treatment engine module 4320.

[0205] In one form of the present technology, the treatment parameter is the instantaneous treatment pressure Pt. In one implementation of this form, the treatment pressure Pt is given by the following equation: Pt = AP(Φ) + P0(1)

[0206] where A is the pressure support, P(Φ) is the pressure-phase waveform value (in the range 0-1) at the current value of phase Φ, and P0 is the base pressure.

[0207] Depending on the values ​​of the parameters A and P, different treatment modes may be defined. In some implementations of this form of the technology, the pressure support A is exactly zero, and therefore the treatment pressure Pt is exactly equal to the base pressure P0 throughout the respiratory cycle. Such implementations are generally grouped under the heading of continuous positive airway pressure (CPAP) treatment.

[0208] The base pressure P0 may be a fixed value that is prescribed and / or manually entered into the RPT device 4000. This alternative method is sometimes referred to as constant continuous positive airway pressure (CPAP) therapy. Alternatively, the base pressure P0 may be continuously calculated as a function of one or more indices or indicators of flow limitation, apnea, hypopnea, patency, and sleep disordered breathing events such as snoring returned by respective algorithms in the therapy engine module 4320. This alternative method is sometimes referred to as APAP therapy.

[0209] In other implementations of this form, referred to as positive pressure ventilation, the pressure support A is non-zero. In some such implementations in which the RPT device 4000 acts as a servo-ventilator, the therapy parameter determination algorithm 4328 takes as input the current measure of ventilation, Vent, and the target ventilation value, Vtgt, and calculates a value for pressure support A to bring the current measure of ventilation, Vent, towards the target value of ventilation, Vtgt. In such implementations, the pressure-phase waveform P(Φ) is configured to achieve a high value during the inspiratory portion of the respiratory cycle and a low value during the expiratory portion of the respiratory cycle.

[0210] In such implementations, the therapy parameter determination algorithm 4328 may apply a continuous control methodology to calculate the pressure support A. One such continuous control methodology is proportional-integral (PI) control according to which the pressure support is calculated as follows:

[0211]

number

[0212] Here, G is the gain of the PI control.

[0213] Other continuous control methodologies that may be applied by the therapy parameter determination algorithm 4328 include proportional (P) control, proportional-differential (PD) control, and proportional-integral-differential (PID) control.

[0214] Another control methodology, referred to as a discrete control methodology, returns a pressure support A that is one of a discrete set of predetermined values.

[0215] 4E is a flow chart illustrating a method 4500 performed by the central controller 4230 as one implementation of the algorithm 4328. Method 4500 begins at step 4520, in which the central controller 4230 compares the indicator of the presence of apnea / hypopnea to a first threshold and determines whether the indicator of the presence of apnea / hypopnea has exceeded the first threshold for a predetermined period of time, thereby indicating that apnea / hypopnea is occurring. If so, method 4500 proceeds to step 4540; otherwise, method 4500 proceeds to step 4530. In step 4540, the central controller 4230 compares the indicator of airway patency to a second threshold. If the indicator of airway patency exceeds a second threshold, thereby indicating that the airway is patent, the detected apnea / hypopnea is deemed to be central and method 4500 proceeds to step 4560; otherwise, the apnea / hypopnea is deemed to be obstructive and method 4500 proceeds to step 4550.

[0216] The central controller 4230 compares the indicator of flow limitation to a third threshold in step 4530. If the indicator of flow limitation exceeds the third threshold, thereby indicating that respiratory flow is limited, then the method 4500 proceeds to step 4550;

[0217] In step 4550, the central controller 4230 increases the treatment pressure Pt by a predetermined pressure increment ΔP, provided that the increased treatment pressure Pt does not exceed the upper limit Pmax. In one implementation, the predetermined pressure increment ΔP and the upper limit Pmax are 1 cmH2O and 20 cmH2O, respectively. The method 4500 then returns to step 4520.

[0218] In step 4560, the central controller 4230 decreases the therapeutic pressure Pt by a decrement, provided that the decreased therapeutic pressure Pt does not fall below the lower limit Pmin. Method 4500 then returns to step 4520. In one implementation, the decrement is proportional to the value of Pt-Pmin, such that the decrease of Pt to the lower limit Pmin in the absence of any detected event is exponential. In one implementation, the proportionality constant is set so that the time constant τ of the exponential decrease of Pt is 60 minutes and the lower limit Pmin is 4 cmH2O. In other implementations, the time constant τ can be as low as 1 minute to as high as 300 minutes, or as low as 5 minutes to as high as 180 minutes. Alternatively, the decrease of Pt can be predetermined so that the decrease of Pt to the lower limit Pmin in the absence of any detected event is linear.

[0219] 5.4.3.3 Control Module A therapy control module 4330 in accordance with one aspect of the present technology receives therapy parameters as input from the therapy engine module 4320 and controls the pressure generator 4140 to deliver a gas flow in accordance with the therapy parameters.

[0220] In one form of the present technology, the treatment parameter is a treatment pressure Pt, and the treatment control module 4330 controls the treatment device 4245 to deliver a gas flow whose mask pressure Pm at the patient interface 3000 is equal to the treatment pressure Pt.

[0221] 5.4.3.4 Fault Condition Detection In one form of the present technology, the central controller 4230 implements one or more methods for detecting a fault condition. The fault condition detected by the one or more methods includes at least one of the following: Power failure (no power or insufficient power) Transducer failure detection Inability to detect the presence of components Operating parameters outside the recommended range (e.g., pressure, flow, temperature, PaO2) Test alarm failure to generate a detectable alarm signal

[0222] Upon detection of a fault condition, the corresponding algorithm signals the presence of a fault by one or more of the following: Initiation of an audible, visual, and / or dynamic (e.g., vibrating) alarm Sending messages to external devices Accident records

[0223] 5.5 Humidifier 5.5.1 Humidifier In one form of the present technology, a humidifier 5000 (for example as shown in Figure 5A) is provided to alter the absolute humidity of air or gas for delivery to a patient relative to ambient air. Generally, the humidifier 5000 is used to increase the absolute humidity and temperature (relative to ambient air) of the airflow before delivery to the patient's airways.

[0224] The humidifier 5000 may comprise a humidifier reservoir 5110, a humidifier inlet 5002 for receiving the airflow, and a humidifier outlet 5004 for delivering the humidified airflow. In some configurations shown in Figures 5A and 5B, the inlet and 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 may comprise a heating element 5240.

[0225] 5.5.2 Humidifier Mechanical Components 5.5.2.1 Water reservoir According to one configuration, the humidifier 5000 may include a water reservoir 5110 configured to hold or maintain a predetermined amount of liquid (e.g., water) to be used to humidify the airflow. The water reservoir 5110 is configured to hold a predetermined maximum amount of water to provide adequate humidification for at least the duration of a respiratory treatment, such as a night's sleep. Typically, the reservoir 5110 is configured to hold several hundred milliliters of water, for example, 300 milliliters (ml), 325 ml, 350 ml, or 400 ml of water. In another form, the humidifier 5000 may be configured to receive the predetermined amount of water from an external water source, such as a building's water system.

[0226] According to one embodiment, the water reservoir 5110 is configured to add humidity to the airflow from the RPT device 4000 as the airflow moves through the RPT device 4000. In one form, the water reservoir 5110 may be configured to encourage the airflow to move in a tortuous path through the reservoir 5110 while coming into contact with a predetermined amount of water within the reservoir.

[0227] According to one form, the reservoir 5110 may be laterally removable from the humidifier 5000, for example as shown in Figures 5A and 5B.

[0228] The reservoir 5110 may be configured to prevent liquid from exiting the reservoir, for example, through any openings and / or between its subcomponents, for example, when the reservoir 5110 is moved and / or rotated from its normal operating orientation. Because the airflow to be humidified by the humidifier 5000 is generally pressurized, the reservoir 5110 may be configured to prevent loss of air pressure due to leakage and / or flow impedance.

[0229] 5.5.2.2 Conductive parts According to one configuration, the reservoir 5110 includes a conductive portion 5120 configured to allow efficient transfer of heat from the heating element 5240 to the volume of water within the reservoir 5110. In one form, the conductive portion 5120 may be arranged as a plate, although other shapes may be suitable. All or part of the conductive portion 5120 may be formed from a thermally conductive material such as aluminum (e.g., about 2 mm thick, e.g., 1 mm, 1.5 mm, 2.5 mm, or 3 mm thick), other thermally conductive metal, or some plastic. In some cases, suitable thermal conductivity may be achieved using a less conductive material with a suitable shape.

[0230] 5.5.2.3 Humidifier Reservoir Dock In one form, the humidifier 5000 may include a humidifier reservoir dock 5130 (as shown in FIG. 5B) configured to receive the humidifier reservoir 5110. In some configurations, the humidifier reservoir dock 5130 may include a locking feature, such as a locking lever 5135, configured to retain the reservoir 5110 within the reservoir dock 5130.

[0231] 5.5.2.4 Water Level Indicator The humidifier reservoir 5110 may include a water level indicator 5150 as shown in Figures 5A-5B. In some forms, the water level indicator 5150 may provide one or more indications to a user, such as the patient 1000 or a caregiver, regarding the amount of predetermined amount of water in the humidifier reservoir 5110. The one or more indications provided by the water level indicator 5150 may include an indication of a maximum, predetermined amount of water, any portion of water, such as 25%, 50%, or 75%, or 200 ml, 300 ml, or 400 ml.

[0232] 5.5.3 Humidifier electrical and thermal components The humidifier 5000 may include a number of electrical and / or thermal components, such as the components listed below.

[0233] 5.5.3.1 Humidifier Transducer The humidifier 5000 may include one or more humidifier transducers (sensors) 5210 instead of or in addition to the transducer 4270 described above. As shown in FIG. 5C , the humidifier transducer 5210 may include one or more of an air pressure sensor 5212, an air flow sensor 5214, a temperature sensor 5216, or a humidity sensor 5218. The humidifier transducer 5210 may provide one or more output signals that may be communicated to a controller, such as the central controller 4230 and / or the humidifier controller 5250. In some forms, the humidifier transducer may be located external to the humidifier 5000 (e.g., in the air circuit 4170) while communicating the output signal to the controller.

[0234] 5.5.3.1.1 Pressure Transducers One or more pressure transducers 5212 may be provided in the humidifier 5000 in addition to or instead of the pressure transducer 4272 provided in the RPT device 4000.

[0235] 5.5.3.1.2 Flow Transducers One or more flow transducers 5214 may be provided in the humidifier 5000 in addition to or instead of the flow transducer 4274 provided in the RPT device 4000.

[0236] 5.5.3.1.3 Temperature Transducers The humidifier 5000 may include one or more temperature transducers 5216. The one or more temperature transducers 5216 may be configured to measure one or more temperatures, such as the temperature of the heating element 5240 and / or the temperature of the airflow downstream of the humidifier outlet 5004. In some forms, the humidifier 5000 may further include a temperature sensor 5216 to detect the temperature of the outside air.

[0237] 5.5.3.1.4 Humidity Transducer In one form, the humidifier 5000 may include one or more humidity sensors 5218 to detect the humidity of a gas, such as outside air. The humidity sensor 5218 may, in some forms, be positioned toward the humidifier outlet 5004 to measure the humidity of the gas being delivered from the humidifier 5000. The humidity sensor may be an absolute humidity sensor or a relative humidity sensor.

[0238] 5.5.3.2 Heating elements A heating element 5240 may, in some cases, be provided in the humidifier 5000 to provide heat input to one or more of the volume of water and / or airflow in the humidifier reservoir 5110. The heating element 5240 may comprise a heat-generating component such as an electrical resistance heating track. One suitable example of a heating element 5240 is a layered heating element as described in PCT International Patent Application Publication No. WO 2012 / 171072, the entire document of which is incorporated herein by reference.

[0239] In some forms, a heating element 5240 may be provided in the humidifier base 5006 as shown in FIG. 5B where heat may be provided to the humidifier reservoir 5110 primarily by conduction.

[0240] 5.5.3.3 Humidifier Controller According to one configuration of the present technology, the humidifier 5000 may include a humidifier controller 5250 as shown in Fig. 5C. In one form, the humidifier controller 5250 may be part of the central controller 4230. In other forms, the humidifier controller 5250 may be a separate controller that may be in communication with the central controller 4230.

[0241] In one form, the humidifier controller 5250 may receive as inputs, for example, indicators of airflow, water in the reservoir 5110, and / or characteristics (e.g., temperature, humidity, pressure, and / or flow rate) of the humidifier 5000. The humidifier controller 5250 may be configured to run or implement a humidifier algorithm and / or provide one or more output signals.

[0242] As shown in FIG. 5C, the humidifier controller may include one or more controllers, such as a central humidifier controller 5251, a heated air circuit controller 5254 configured to control the temperature of the heated air circuit 4171, and / or a heating element controller 5252 configured to control the temperature of the heating element 5240.

[0243] 5.6 Respiratory waveform Figure 6B shows a typical respiratory waveform model for a sleeping person. The horizontal axis is time, and the vertical axis is respiratory flow. Although parameter values ​​may vary, a typical breath may have the following approximate values: tidal volume Vt, 0.5 L; inspiratory time Ti, 1.6 s; peak inspiratory flow Qpeak, 0.4 L / s; expiratory time Te, 2.4 s; peak expiratory flow Qpeak, -0.5 L / s. The total duration of the breath Ttot is approximately 4 s. People typically breathe at a respiratory rate of approximately 15 breaths per minute (BPM) with a ventilation volume Vent of approximately 7.5 L / min. A typical duty cycle, i.e., the ratio of Ti to Ttot, is approximately 40%.

[0244] Figure 6B shows a patient in non-REM sleep who normally breathes over a period of approximately 90 seconds, in this case with approximately 34 inspirations, treated with auto-PAP and a mask pressure of approximately 11 cmH2O. The top channel shows oxygen saturation (SpO2), with the scale ranging from 90 to 99% saturation vertically. The patient maintained approximately 95% saturation throughout the period shown. The second channel shows quantitative respiratory airflow, with the scale ranging from -1 to +1 LPS vertically, also with positive inspiration. The third and fourth channels show chest and abdominal movement.

[0245] Figure 6C shows a patient's pretreatment polysomnography. There are 11 signal channels, spanning a horizontal length of 6 minutes from top to bottom. The top two channels are EEGs (electroencephalograms) from different scalp locations. Periodic spikes in the second EEG represent cortical arousals and associated activity. The bottom third channel is a submandibular EMG (electromyogram). Increased activity around the time of arousal represents genioglossus recovery. The fourth and fifth channels are electrooculograms (EOGs). The sixth channel is an electrocardiogram. The seventh channel shows pulse oximetry (SpO2) with repetitive desaturations ranging from less than 70% to more than 90%. The eighth channel is respiratory airflow measurement using a nasal cannula connected to a differential pressure transducer. Repetitive apneas of 25–35 seconds alternate with 10–15 second bursts of recovery breathing, consistent with increased EEG arousals and EMG activity. The ninth channel shows chest movement, and the tenth channel shows abdominal movement. The abdomen shows a crescendo of movement over the length of the apnea that leads to arousal. Both are chaotic during arousal due to the rough body movements during recovery hyperventilation. Therefore, the apnea is obstructive and the condition is severe. The lowest channel is postural and shows no change in this example.

[0246] Figure 6D shows patient flow data as the patient experiences a series of total obstructive apneas. The duration of the recording is approximately 160 seconds. Flow rates range from approximately +1 L / s to approximately -1.5 L / s. Each apnea lasts approximately 10-15 seconds.

[0247] 5.7 Heat Moisture Exchanger (HME) 5.7.1 Overview of HME 7A-7D illustrate an example of an HME in accordance with the present technology. FIG. 7A shows a cross section of an HME 7000 comprising a corrugated structure 7002 comprising a plurality of corrugations 7030 between a generally flat upper substrate structure 7010 and a generally flat lower substrate structure 7020 to form a concertina-shaped layer 7001. Layer 7001 comprises a plurality of upper channels 7012 formed between the upper surface of corrugated structure 7002 and upper structure 7010. Layer 7001 also comprises a plurality of lower channels 7022 formed between the lower surface of corrugated structure 7002 and lower structure 7020. HME 7000 allows the flow of breathable and exhaled gases along the surface of the corrugated structure through the plurality of upper channels 7012 and lower channels 7022 for the exchange of heat and moisture. Moisture is absorbed from the exhaled gases exhaled by the patient and retained in the material of corrugated structure 7002. The material of the corrugations 7030, the top structure 7010, and / or the bottom structure 7020 may comprise paper or a paper-based material capable of absorbing water and / or heat. The material of the corrugations 7030, the top structure 7010, and / or the bottom structure 7020 may be porous, water-permeable, and / or air-permeable. The retained moisture may then be re-delivered to the patient by humidifying the breathable gas flow delivered to the patient's airway. In other words, the breathable gas flow delivered to the patient's airway may absorb moisture from the HME 7000. Figure 7B depicts various dimensions of an HME according to these examples.

[0248] The plurality of corrugations 7030 increases the surface area of ​​the corrugated structure 7002 allowing for increased active surface area for heat and moisture exchange to occur between the corrugated structure 7002 and the surrounding volume provided by the plurality of upper and lower channels 7012, 7022. The top and bottom end structures 7010, 7020 may be formed from the same heat and moisture exchange material as the corrugated structure 7030. Alternatively, the top and / or bottom end structures 7010, 7020 may be formed from a rigid or semi-rigid material that does not absorb moisture to support the corrugated structure 7002.

[0249] The humidification performance of the HME 7000 depends on the effective surface area of ​​the HME 7000 within a given volume of space. The effective surface area is the surface area of ​​the HME 7000 exposed to the breathable gas flowing along the surface of the HME where heat and moisture exchange occurs. The surface area per unit volume of the HME 7000 can be adjusted by incorporating corrugations 7030 within the HME 7000's heat and moisture exchange section. The surface area per unit volume may also be adjusted by varying at least one of the fin thickness, pitch, or height of the corrugations or pleats, which affect the surface area per unit volume of the HME 7000.

[0250] The HME 7000 may include multiple layers 7001 stacked along the vertical axis of the HME 7000, as shown in FIG. 7C. The layers 7001 may be stacked vertically, with the bottom structure 7020 stacked on top of the corrugated structure 7002 of the adjacent layer 7001 below. There may also be several layers 7001 of HME stacked horizontally. Having many layers 7001 with corrugated structures 7002 stacked along the vertical axis of the HME 7000 further increases the surface area per unit volume of the HME. This increase in surface area within a given size range can increase the efficiency of the HME 7000 in heat and moisture exchange. The layers 7001 may also be compressed under a preload, as depicted in FIG. 7D, to increase the number of layers within a given size range and thereby increase the surface area per unit volume. The preload is calculated according to the following formula:

[0251]

number

[0252] where P is the preload and h start is the height of the corrugations or pleats before compression, where h final is the height of the corrugation after compression.

[0253] Alternatively, the final three-dimensional shape of the HME 7000 may be formed by combining layers 7001 of different sizes and shapes to create an irregularly shaped HME 7000 that is adapted to fit within the plenum chamber 3200 of the patient interface 3000. The layers 7001 may be laser cut to form the desired shape and size.

[0254] 8A-8D, which shows another example, the HME 7000 may be rolled from a single strip layer 7001 with corrugations 7002 extending from a surface of a bottom structure 7020 to form a plurality of corrugations 7030. The single strip layer 7001 may be rolled such that the upper folds 7031 of the corrugations 7030 engage the lower surface of the bottom structure 7020. This configuration ensures that a plurality of channels 7012 are maintained between each roll of the single strip layer 7001. The HME 7000 may be positioned within the plenum chamber 3200 of the patient interface 3000.

[0255] 9A-9J show another example of the present technology. In this example, the patient interface 3000 has a releasably engageable cushion assembly 3130 comprising a plurality of cushion assembly engagement members 3135 in the form of clips with resilient flanges that releasably engage a mask frame 3250. The mask frame 3250 comprises mask frame engagement members 3255 in the form of recesses or holes that allow the resilient flanges of the cushion assembly engagement members 3135 to pass through and releasably engage the mask frame engagement members. Alternatively, the cushion assembly 3130 may engage the mask frame by other methods, such as hooks, adhesive, interference, or frictional engagement. The cushion assembly 3130 comprises a seal-forming structure 3100. The seal-forming structure 3100 may form a seal with an entrance to the patient's airway. The seal-forming structure 3100 of the patient interface 3000 may also comprise a pair of nasal puffs or nasal pillows, each constructed and arranged to form a seal with a respective nostril of the patient's nose, or alternatively, the seal-forming structure may form a seal with a nostril and the mouth.

[0256] The exemplary patient interface 3000 further includes a removable HME 7000 that removably engages the patient interface 3000, and the HME 7000 may be positioned within an HME housing portion 3420 of a vent adapter 3410. The HME 7000 may include at least one HME engaging member 7004 positioned on an HME frame 7003. The at least one HME engaging member 7004 may include a clip, and each clip may removably engage with a corresponding vent adapter engaging member 3415. The vent adapter 3410 may include a vent 3400 and a mask inlet 3260 positioned in front of the vent. The vent adapter 3410 may removably engage with the remainder of the patient interface 3000 to position the removably engaged HME 7000 within its HME housing portion 3420. The vent adapter 3410 may position the HME 7000 in the flow path of breathable gas within the plenum chamber 3200 of the patient interface 3000, or may orient the HME's channels 7012, 7022 to be generally aligned or parallel to the flow path of the breathable gas stream, thereby permitting flow through the HME via the channels 7012, 7022. Positioning the HME 7000 close to the entrance of the patient's airway may maximize moisture capture and retention provided to the HME 7000 material during exhalation. The orientation of the channels 7012, 7022 may also allow the humidified gas stream exhaled by the patient to flow in the opposite direction through the HME's channels 7012, 7022.

[0257] The vent adapter 3410 shown in FIGS. 12A-12D may position the HME 7000 within the plenum chamber 3200 and may separate the plenum chamber 3200 into a forward plenum chamber 3240 and a rear plenum chamber 3230. This positioning of the HME 7000 may position the vent 3400 and inlet 3260 on the front side of the HME 7000 as part of the forward plenum chamber 3240, with the entrance to the patient's airway located on the rear side of the HME 7000 adjacent to the rear plenum chamber 3230. This configuration may allow the patient's exhaled gas flow to flow into the rear plenum chamber 3240 before ventilation, thereby allowing any moisture to be retained within the HME 7000 before loss through the vent 3400. This configuration may also allow the breathable gas flow to flow through the HME 7000 before re-delivery of trapped moisture to the patient. Thus, the housing portion 3410 may be configured to redirect humidified air to the patient via an HME 7000 positioned within the flow path of the patient interface 3000.

[0258] The vent adapter 3410 may include a receiving portion 3440 for receiving a respective engaging member 7004 of the HME frame 7003. The receiving portion 3440 may releasably couple with the engaging member 7004 in a snap-fit ​​manner. The vent adapter 3410 may include an attachment member 3450 for releasably coupling the vent adapter 3410 to the mask frame 3250. The attachment member 3450 may attach the vent adapter 3410 to the mask frame using a snap-fit.

[0259] The auxiliary vent 3401 may also be located at the rear of the HME in the rear plenum chamber 3240 to offset CO2 buildup within this volume. For example, in the case of a full-face mask, the additional volume (i.e., dead space volume) within the rear plenum chamber 3240 may result in undesirable and / or excessive CO2 buildup occurring within this space compared to a smaller mask. To mitigate this effect, the auxiliary vent 3401 may be located on the rear or patient side of the HME 7000 near the patient's airway. Locating the auxiliary vent 3401 at the rear of the HME 7000 provides some ventilation of the humidified breathable gas flow prior to delivery to the patient. To compensate for this ventilation of humidified air, overall humidification performance may be maintained by increasing the HME 7000's ability to humidify the breathable gas flow within a given volume of the plenum chamber 3200.

[0260] The vent adapter 3410 may include a baffle 3430 to separate the incoming flow of breathable gas from the outgoing flow of CO2. The baffle 3430 may separate these gas flows from one another so that they do not interfere with one another. U.S. Patent No. 7,934,501, incorporated herein by reference in its entirety, describes further examples and features of baffles that may be applicable to the exemplary patient interface 3000.

[0261] 10-10F depict an example of an HME frame 7003 in accordance with the present technology. The HME frame 7003 may include one or more engagement members 7004. The engagement members 7004 may releasably engage with a vent adapter 3410. Alternatively, the engagement members 7004 may orient the HME frame 7003 to releasably engage with the plenum chamber 3200 or the mask frame 3250 of the patient interface 3000. The HME frame may include one or more frame openings 7006 that allow breathable and / or exhaled gas flow through the frame openings 7006 and the HME layer 7001. The HME frame 7003 may include one or more HME retention members 7005. The HME retention members 7005 may hold the HME layer 7001 in place and may also provide structural support for the HME frame 7003. The HME retention member 7005 may be provided on the front and / or rear surfaces of the HME frame 7003. In the front and rear views shown in FIGS. 10A and 10B, respectively, the HME frame 7003 has a generally rectangular shape. It should be understood that the HME frame 7003 may have other shapes as well to provide the most efficient use of space within the patient interface 3000. For example, the HME frame 7003 may have a square, oval, circular, triangular, or other polygonal shape. Thus, the HME layer 7001 may be shaped to fit the interior shape of the HME frame 7003 depending on the shape of the HME frame 7003. FIG. 10D shows a top view of the HME frame 7003, in which it can be seen that the HME frame 7003 according to this example of the present technology is curved backward at its side edges to correspond to the shape of the patient interface 3000. Of course, the HME frame 7003 may have a shape that is equally flat or curved forward from this view, depending on the shape of the patient interface 3000.

[0262] As shown in FIGS. 11A-11G, the HME 7000 may be stacked in layers 7001 and may further comprise a rigid portion supporting the HME frame 7003. The HME layers 7001 may be held within the HME frame 7003 by one or more HME retention members 7005. The HME frame 7003 may comprise frame openings 7006 defined by corrugations 7030 and aligned with multiple channels 7012, 7022 extending through the layer 7001 of the HME 7000. The frame openings 7006 allow gas flow in both directions through the HME, thereby retaining heat and moisture exchange for re-delivery to the patient. The inwardly curved, predetermined three-dimensional shape of the HME frame 7003 fits within the plenum chamber 3200 of the patient interface 3000 to avoid contact with the patient's face when the patient interface 3000 is positioned on the face. Other predetermined three-dimensional shapes may be provided to avoid contact with the patient's face while maintaining the ability of the HME 7000 to fit within the plenum chamber 3200 of the patient interface 3000.

[0263] FIG. 13A shows a flow diagram of an exemplary process that may be followed to select an appropriate heat and moisture exchanger (HME or HMX). The exemplary process may be used to test whether an HME can obtain desired parameters for humidification performance. The process is adapted from ISO 9360. The process involves simulating humidified lungs and placing the lungs in fluid communication with a patient interface under various test conditions. The test conditions may include: i) No humidification ii) Passive humidification using an in-mask HME. A multi-layer corrugated HME was used with the F-pleat corrugation structure shown in Figure 13C with the properties listed in the "HME tested (pleat F)" column in Figure 13D. iii) Active humidification using a powered humidifier H5i at 23°C and 80% RH iv) Active humidification using a powered humidifier H5i at 30°C and 80% RH

[0264] As shown in the typical results presented in Figure 13B, the weight loss of humidified lungs was used as an indicator to simulate the humidity lost in the lungs of patients undergoing RPT treatment. As expected, no humidification (i) showed the highest weight loss, simulating the humidity lost by patients undergoing RPT treatment without any additional humidification. This may ultimately lead to respiratory discomfort. Passive humidification performed better than active humidification with the H5i at 23°C and 80% RH. Passive humidification also approached the performance of extreme humidification using a powered humidifier H5i at 30°C and 80% RH. Testing was performed under ambient conditions of 15.5°C and 30% RH. The HME used in the test had a surface area per unit volume of 5.4 m, as listed in the "Tested HME (Pleated F)" column in Figure 13D. 2 / m 3 It was subjected to a 6% preload.

[0265] 13C shows various corrugation or pleat configurations that form a corrugated structure included in an unpreloaded HME. F-pleats may be used to form a corrugated structure with multiple corrugated layers of the HME. In the unpreloaded assembled configuration, the corrugated structure may be formed from corrugated paper having a height of 0.9 mm and a paper grade of 65 gsm.

[0266] FIG. 13D shows various corrugated structure parameters according to an embodiment of the present technology. A "tested HME" with multiple layers in pleat F configuration was subjected to a 6% preload. This configuration was measured at 8360 mm 3 with a total volume of 5.42m 2 / m 3 The HME was given a surface area per unit volume of 4560 mm. The overall flow impedance was found to be 0.47 cmH2O. Under optimal conditions, the HME had a diameter of 4560 mm. 3 with a total volume of 7.5m 2 / m 3The HME may comprise 26 layers stacked under a 32% preload to provide a surface area per unit volume of 1.6 cmH2O. The HME has a flow impedance of 1.6 cmH2O, which may provide improved humidification performance within an acceptable impedance range relative to smaller HMEs. Figure 13E shows the dimensions measured to provide the parameters listed in Figure 13D. The corrugation perimeter is the length of paper material forming a single corrugation or pleat. As listed in Figure 13D, this length is maintained between the tested and optimal HMEs as the preload is increased to compress the corrugations into an even smaller volume. A compressive force under preload is applied to the corrugation folds to reduce the pleat height while maintaining the pleat pitch. The stack corresponds to multiple layers stacked vertically into the three-dimensional shape shown, where the stack height is reduced as the preload is increased, thereby increasing the surface area per unit volume of the HME.

[0267] Embodiments of the present technology are directed to an HME 7000 positioned within the functional dead space of various full-face patient interfaces 3000 (see FIGS. 14A-14F, 15A-15, and 16). The HME 7000 may be positioned within the plenum chamber 3200 so that it remains between the patient's 1000 airway and the mask vent 3400 / inlet 3260 of the patient interface 3000. The HME 7000 may be supported and held in place by a support membrane 7050, which may be connected to the inner wall of the plenum chamber 3200. The HME 7000 in these embodiments is circular in shape and has a thickness of approximately 5-10 mm. Alternatively, the HME material may be molded into a contoured shape that directly fits the interior shape of the plenum chamber 3200, in which case the HME forms a complementary shape to the interior of the plenum chamber 3200. In this case, the shape may be a three-dimensional surface with a thickness of approximately 1-10 mm.

[0268] In an example of a non-invasive patient interface 3000 in accordance with one aspect of the present technology, the patient interface 3000 may comprise the following functional aspects: a seal-forming structure 3100, a plenum chamber 3200, an HME 7000 positioned within a functional dead space within the plenum chamber 3200, a support membrane 7050 structure for holding the HME 7000 in place, a positioning and stabilising structure 3300, and a connection port or inlet 3260 for connecting to an air circuit 4170. In some forms, the functional aspects may be provided by one or more physical components. In some forms, a single physical component may provide one or more functional aspects. In use, the seal-forming structure 3100 is positioned to surround an entrance to the patient's airways to facilitate the delivery of air at positive pressure to the airways.

[0269] A positioning and stabilising structure 3300 may be provided for releasably securing the patient interface 3000 to the patient 1000. The positioning and stabilising structure 3300 may include a plurality of length adjustable straps to allow the patient interface to fit comfortably and securely on the patient 1000 so that a pneumatic seal is formed around the patient's airway by the seal-forming structure 3100. Strap connectors 3301 may be provided for releasably securing the straps of the positioning and stabilising structure 3300 to the patient interface 3000. The straps of the positioning and stabilising structure 3300 may include hook and loop material for length adjustment and to allow the straps of the positioning and stabilising structure 3300 to be attached to and detached from the strap connectors 3301. It should be understood that the strap connectors 3301 may be releasably attached to the patient interface 3000 or alternatively the strap connectors may be integrally formed with the patient interface.

[0270] The positioning of the HME 7000 within the patient interface may be altered to adjust moisture absorption performance. For example, the distance between the HME and the patient's 1000 airway may be adjusted. Also, the distance between the HME 7000 and the vent 3400 and / or the inlet 3260 may be adjusted. Adjusting the positioning of the HME 7000 can change the moisture absorption performance of the HME by adjusting the position of the HME 7000 relative to the patient's 1000 airway. That is, the closer the HME 7000 is positioned to the patient's 1000 airway, the closer the HME 7000 is to the moisture source during exhalation and the closer it is to the humidification target during inhalation. However, the HME 7000 may be positioned such that it avoids contact with the patient's face. Similarly, adjusting the position of the HME 7000 can affect flow impedance due to its position relative to the inlet 3260 and its effect on CO2 outflow, which is affected by its position relative to the vent 3400. By locating the HME 7000 within the functional dead space of the patient interface 3000, the HME can occupy a larger volume compared to the volume the HME 7000 occupies within the air delivery conduit or elbow. This, in turn, allows for greater flexibility in locating the HME 7000 within a larger volume to minimize impedance to therapy flow and CO2 outflow while maximizing moisture absorption performance. While all of the aforementioned advantages also apply to a molded HME insert, the HME insert concept may offer greater design control and reduce trade-offs between conflicting functions. Similarly, the thickness and area of ​​the HME 7000 may be varied to adjust these properties. For example, an HME 7000 with increased surface area will have improved moisture absorption performance. Additionally, a thinner HME 7000 can increase its permeability and therefore reduce impedance.

[0271] In these examples, the flexible support membrane 7050 may be positioned to connect into the interior wall of the plenum chamber 3200 and may support the HME 7000 within the functional dead space of the patient interface 3000. The flexible support membrane 7050 may be formed from a flexible material such as silicone, but may also be formed from an HME material. The flexibility allows the flexible support membrane 7050, which holds the HME 7000, to be easily manipulated and moved. The flexible support membrane 7050 may also be impermeable to humidified air exhaled from the patient's 1000 airway to avoid any humidification loss through the vent 3400. The impermeability of the flexible support membrane 7050 may allow exhaled humidified air to pass through the HME 7000 to maximize moisture absorption performance.

[0272] In another example, the HME 7000 may be positioned within a functional dead space within the plenum chamber 3200 of a patient interface 3000 in the form of a nasal mask supported by a support membrane 7050.

[0273] In one example of the present technology, the added humidity above ambient humidity is 10 cm 3 The measurements were performed using a Humiflo HME, as shown in Figure 17, with a diameter of 35 cm and a volume of 1000 psi. The HME was positioned within the functional dead space of the ResMed Quattro FX patient interface. Note that leaks in the patient interface can result in an increase in the average flow rate through the plenum chamber of the patient interface, which ultimately has a negative effect by reducing humidity within the patient interface due to losses through the system. Added humidity was measured at therapeutic pressures ranging from 4 cmH2O to 20 cmH2O (flow rates ranging from 20 L / min to 50 L / min). Figure 17 shows an added absolute humidity of approximately 5 mg / L to 18 mg / L. More specifically, the graph shows an added absolute humidity of 9.5 mg / L to 17.5 mg / L at the same flow rates. Humidity over time at a particular pressure ranges from the minimum humidity occurring during inspiration to the maximum humidity during expiration. Average humidity was measured throughout the respiratory cycle as a comparative indicator.

[0274] 5.8 Glossary For purposes of this disclosure, in certain aspects of the technology, one or more of the following definitions may apply. In other aspects of the technology, other definitions may apply.

[0275] 5.8.1 General Provisions 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 atmospheric air mixed with some other combination of breathing gases, for example oxygen.

[0276] Ambient: In certain forms of the present technology, the term ambient is interpreted to mean (i) the area outside the treatment system or patient, and (ii) the environment immediately surrounding the treatment system or patient.

[0277] For example, the ambient humidity for a humidifier may be the humidity of the air immediately surrounding the humidifier, such as the humidity in the room the patient is sleeping in. Such ambient humidity may be different from the humidity outside the room in which the patient is sleeping.

[0278] In other examples, the ambient pressure may be the pressure immediately surrounding the body or pressure outside the body.

[0279] In certain embodiments, ambient (e.g., acoustic) noise may be considered to be the background noise level in the room in which the patient is located, excluding, for example, noise generated by the RPT device or noise emanating from a mask or patient interface. Ambient noise may also be generated by noise sources outside the room.

[0280] Continuous Positive Airway Pressure (CPAP): Continuous positive airway pressure (CPAP) therapy is understood to mean the application of a predetermined volume of air to the entrance to the airways at a pressure that is continuously positive relative to the atmosphere and preferably substantially constant over the patient's respiratory cycle. In some forms, the pressure at the entrance to the airways is slightly higher during expiration and slightly lower during inspiration. In some forms, the pressure varies during different respiratory cycles of the patient, for example, being increased in response to the detection of an indication of partial upper airway obstruction and decreased in the absence of an indication of partial upper airway obstruction.

[0281] 5.8.2 Aspects of the respiratory cycle Apnea: An apnea is said to occur when the flow rate drops below a predetermined threshold for a predetermined duration, e.g., 10 seconds. Obstructive apnea is said to occur when some obstruction of the airway does not allow airflow despite patient effort. Central apnea is said to occur when apnea is detected due to reduced or absent respiratory effort despite a patent airway. Mixed apnea occurs when reduced or absent respiratory effort coincides with airway obstruction.

[0282] Respiratory rate: The rate at which a patient is spontaneously breathing, usually measured in breaths per minute.

[0283] Duty cycle: The ratio of inspiratory time Ti to total breathing time Ttot.

[0284] Effort (breathing): Respiratory effort is said to be the work done by a spontaneous breather trying to breathe.

[0285] Expiratory portion of the respiratory cycle: the period from the start of expiratory flow to the start of inspiratory flow.

[0286] Flow Limitation: Flow limitation is understood to be a state of affairs in a patient's breathing where an increase in effort by the patient does not result in a corresponding increase in flow. If flow limitation occurs during the inspiratory portion of the respiratory cycle, it may be considered inspiratory flow limitation. If flow limitation occurs during the expiratory portion of the respiratory cycle, it may be considered expiratory flow limitation.

[0287] The types of flow-limiting inspiratory waveforms are as follows: (i) Flat: A rise followed by a relatively flat section, then a fall. (ii) M-shape: It has two local peaks, one in the rising section and one in the falling section, and there is a relatively flat area between the two peaks. (iii) Chair shape: has a single local peak in the rising section, followed by a relatively flat section. (iv) Inverted chair shape: a relatively flat section followed by a single local peak, which is on the trailing edge.

[0288] Hypopnea: Hypopnea is interpreted as a reduction in flow rate, rather than an interruption of flow. In one form, hypopnea may be said to occur when there is a reduction in flow rate below a threshold for a given duration. Central hypopnea is said to occur when hypopnea is detected due to a reduction in respiratory effort. In one form in adults, a hypopnea is considered to occur when either of the following occurs: (i) a 30% reduction in breathing in the patient for at least 10 seconds plus an associated 4% desaturation, or (ii) a reduction in breathing in the patient for at least 10 seconds (but less than 50%) with an associated desaturation or arousal of at least 3%.

[0289] Hyperventilation: An increase in flow to a level higher than normal.

[0290] Inspiratory portion of the respiratory cycle: The period from the start of inspiratory flow to the start of expiratory flow is taken to be the inspiratory portion of the respiratory cycle.

[0291] Patency (Airway): The degree to which the airway is open, or the extent to which the airway is open. A patent airway is open. Airway patency may be quantified, for example, using a value of one (1) for open and a value of zero (0) for closed (obstructed).

[0292] Positive end-expiratory pressure (PEEP): Pressure above atmospheric pressure within the lungs that exists at the end of expiration.

[0293] Peak flow (Qpeak): The maximum value of flow during the inspiratory portion of the respiratory flow waveform.

[0294] Respiratory flow, airflow, patient airflow, respiratory airflow (Qr): These synonyms may be understood to refer to an RPT device's estimate of respiratory airflow, as opposed to "true respiratory flow" or "true respiratory airflow," which is the actual respiratory flow experienced by the patient, usually expressed in units of liters per minute.

[0295] Tidal Volume (Vt): The amount of air inhaled or exhaled during normal breathing when no extra effort is exerted.

[0296] (Inspiratory) Time (Ti): The duration of the inspiratory portion of the respiratory flow waveform.

[0297] (Expiratory) Time (Te): The duration of the expiratory portion of the respiratory flow waveform.

[0298] (Total) Time (Ttot): The total duration between the start of the inspiratory portion of one respiratory flow waveform and the start of the inspiratory portion of the subsequent respiratory flow waveform.

[0299] Typical Recent Ventilation: The ventilation value around which recent values ​​over some given timescale tend to cluster, i.e., a measure of the central tendency of recent values ​​of ventilation.

[0300] Upper Airway Obstruction (UAO): Includes both partial and complete upper airway obstruction. This may be associated with a flow-limited state (Starling resistance behavior) in which the level of flow increases only slightly or may even decrease as the pressure difference across the upper airway increases.

[0301] Vent: A measure of the total amount of gas exchanged by a patient's respiratory system per unit time, including both inspiratory and expiratory flow. When expressed as a volume per minute, this volume is often referred to as "minute ventilation." Minute ventilation is sometimes given simply as volume, which is understood to be the volume per minute.

[0302] 5.8.3 RPT Device Parameters Flow (or flow): The instantaneous volume (or mass) of air delivered per unit time. Flow and ventilation have the same magnitude of volume or mass per unit time, but flow is measured over a much shorter period of time. In some cases, reference to flow is to a scalar quantity, i.e., a quantity having only magnitude. In other cases, reference to flow is to a vector quantity, i.e., a quantity having both magnitude and direction. When referred to as a signed quantity, flow may be nominally positive for the inspiratory portion of the patient's respiratory cycle and therefore negative for the expiratory portion of the patient's respiratory cycle. Flow is given the symbol Q. Total flow, Qt, is the flow of air exiting the RPT device. Vent flow, Qv, is the flow of air exiting the vent to allow the outflow of exhaled gases. Leak flow, Ql, is the flow of unintentional leakage from the patient interface system. Respiratory flow, Qr, is the flow of air received into the patient's respiratory system.

[0303] Leak: The term leak is understood to be the flow of air into the surroundings. A leak may be intentional, for example to allow the escape of exhaled CO2. A leak may also be unintentional, for example as a result of an imperfect seal between the mask and the patient's face. In one example, a leak may occur at a swivel elbow.

[0304] Conducted noise (acoustic): In this document, conducted noise refers to noise transmitted to the patient by air pressure pathways, such as the air circuit and patient interface, and the air within them. In one form, conducted noise may be quantified by measuring the sound pressure level at the end of the air circuit.

[0305] Radiated noise (acoustic): In this document, radiated noise refers to the noise transmitted to the patient by the ambient air. In one form, radiated noise may be quantified by measuring the sound power level / sound pressure level of the target object according to ISO 3744.

[0306] Vent noise (acoustic): In this document, vent noise refers to the noise generated by air flow through any vents, such as vent holes in the patient interface.

[0307] Pressure: Force per unit area. Pressure is measured in cmH2O or gf / cm 2 It may be measured in a range of units, including hectopascals. 1 cmH2O is 1 g-f / cm 2 and is approximately 0.98 hectopascals. Throughout this specification, pressures are given in units of cmH2O unless otherwise stated. The pressure in the patient interface is given the symbol Pm, while the therapeutic pressure, which represents the target value to be achieved by the mask pressure Pm at the current time instant, is given the symbol Pt.

[0308] Sound power: The energy per unit time transmitted by a sound wave. Sound power is proportional to the square of the sound pressure times the area of ​​the wavefront. Sound power is usually measured in decibels (SWL), i.e., usually in units of 10 -12 It is given in units of decibels relative to a reference power, interpreted as watts.

[0309] Sound pressure: the local deviation from ambient pressure at a given time as a result of sound waves traveling through a medium. Sound pressure is usually measured in units of decibels SPL, i.e., the unit taken to be the threshold of human hearing, typically 20 x 10-6 It is given in units of decibels relative to a reference pressure, interpreted as pascals (Pa).

[0310] 5.8.4 Ventilation Terminology Adaptive servo-ventilator: A ventilator that has a variable ventilation rather than a predetermined target ventilation. The variable target ventilation may be learned from some characteristics of the patient, for example the patient's respiratory characteristics.

[0311] Backup Rate: A ventilator parameter that defines the minimum respiratory rate (typically in breaths / minute) that will be delivered to the patient if the ventilator is not otherwise activated.

[0312] Cycling: End of the inspiratory phase of a ventilator. When a ventilator delivers breaths to a spontaneously breathing patient, the ventilator is said to be cycled to stop delivering breaths at the end of the inspiratory portion of the breathing cycle.

[0313] EPAP (or EEP): The base pressure to which varying pressure during expiration is added to produce the desired mask pressure the ventilator attempts to achieve at a given time.

[0314] IPAP: The desired mask pressure that the ventilator attempts to achieve during the inspiratory portion of the breath.

[0315] Pressure Support: A number indicating the increase in pressure during ventilator inspiration over the pressure during ventilator expiration, generally referring to the difference in pressure between maximum during inspiration and minimum during expiration (e.g., PS = IPAP - EPAP). In some contexts, pressure support refers to the difference the ventilator attempts to achieve, rather than the difference it actually achieves.

[0316] Servo-ventilator: A ventilator that measures patient ventilation with a target ventilation and adjusts the level of pressure support to bring patient ventilation towards the target ventilation.

[0317] Spontaneous / Timed (S / T) - A mode of a ventilator or other device that attempts to detect the onset of a breath in a spontaneously breathing patient. However, if the device does not detect a breath within a predetermined period of time, the device automatically begins delivering a breath.

[0318] Runout: A term equivalent to pressure support.

[0319] Triggered Condition: When a ventilator delivers a breath of air to a spontaneously breathing patient, the ventilator is said to be triggered to do so at the start of the respiratory portion of the breathing cycle by the patient's efforts.

[0320] Ventilator: A mechanical device that provides pressure support to a patient to perform some or all of the work of breathing.

[0321] 5.8.5 Facial Anatomy The outer walls or "wings" (plural: alae) of each nostril

[0322] Alar outermost point: The outermost point of the nasal ala.

[0323] Alar curvature (or alar tip) point: The most posterior point on the curvature baseline of each alar, found at the crease formed by the attachment of the alar to the cheek.

[0324] Auricle: the entire visible outer part of the ear.

[0325] (Nasal) skeleton: The nasal skeleton comprises the nasal bones, the frontal process of the maxilla, and the nasal part of the frontal bone.

[0326] (Nasal) Cartilaginous Skeleton: The cartilaginous skeleton of the nose comprises the nasal septum, lateral cartilages, greater alar cartilages, and lesser alar cartilages.

[0327] Columella: the piece of skin that separates the nostrils and extends from the tip of the nose to the upper lip.

[0328] Columella angle: The angle between a line drawn through the midpoint of the nostril opening and a line drawn perpendicular to the Frankfort horizontal while crossing the nasal spine.

[0329] Frankfort horizontal plane: A line extending from the lowest point of the orbital rim to the left tragus point, which is the deepest point of the notch above the auricle of the pinna.

[0330] Glabellar: The most prominent point in the midsagittal plane of the forehead, located on the soft tissue.

[0331] Lateral nasal cartilage: roughly triangular plate of cartilage, the superior margin of which is attached to the nasal bone and the frontal process of the maxilla, and the inferior margin of which is connected to the greater alar cartilage.

[0332] Greater alar cartilage: a plate of cartilage located below the lateral nasal cartilage. The greater alar cartilage curves around the anterior part of the nostril. The posterior end of the greater alar cartilage is attached to the frontal process of the maxilla by a tough fibrous membrane that contains three or four small cartilages of the alar.

[0333] Nostrils (nostrils): roughly oval openings that form the entrance to the nasal cavity. The singular form of nares is naris (nostril). The nostrils are separated by the nasal septum.

[0334] Naso-labial sulcus or naso-labial fold: a fold or groove of skin that separates the cheek from the upper lip and runs from either side of the nose to the corners of the mouth.

[0335] Nasolabial angle: the angle between the columella and upper lip across the nasal spine.

[0336] Lower ear base: lowest point of attachment of the pinna to the skin of the face.

[0337] Superior ear base: the uppermost point of attachment of the pinna to the skin of the face.

[0338] Nasal tip: the most prominent point or apex of the nose that can be identified in a lateral view of the rest of the head.

[0339] Philtrum: a median groove extending from the lower edge of the nasal septum to the upper edge of the lip in the upper lip region.

[0340] Pogonion: The anterior midpoint of the jaw, located on the soft tissue.

[0341] Nasal ridge: The nasal ridge is a midline protrusion of the nose that extends from the root to the tip.

[0342] Sagittal plane: vertical plane passing from front to back dividing the body into right and left halves.

[0343] Nasal root: Located on the soft tissue, the most concave point lying on the area of ​​the frontonasal suture.

[0344] Septal cartilage (nasal septum cartilage): The nasal septum cartilage forms part of the septum and separates the front of the nasal cavity.

[0345] Lowest point of the alar: The lower edge of the base of the alar where it joins the skin of the upper (upper) lip.

[0346] Nasal spine point: located on the soft tissue, the point where the columella meets the upper lip in the midsagittal plane.

[0347] Supramental point: The most concave point on the midline of the lower lip between the midpoint of the lower lip and the soft tissue pogonion.

[0348] 5.8.6 Skull anatomy Frontal bone: The frontal bone includes the greater vertical part, the scales frontalis, which corresponds to the area known as the forehead.

[0349] Mandible: The mandible forms the lower jaw. The mental protuberance is the bony protuberance of the jaw that forms the chin.

[0350] Maxilla: The maxilla forms the upper jaw and is located superior to the mandible and inferior to the orbit. The frontal process of the maxilla projects upwards by the side of the nose and forms part of the lateral border of the nose.

[0351] Nasal bones: The nasal bones are two small, oval bones that vary in size and shape in different individuals. They are located side by side in the middle and lower parts of the face and their junction forms the "bridge" of the nose.

[0352] Nasion: the intersection of the frontal bone and the two nasal bones, a concave area just between the eyes and the top of the bridge of the nose.

[0353] Occipital bone: The occipital bone is located at the lower back of the skull. It contains an oval opening, the foramen magnum, through which the cranial cavity communicates with the spinal canal. The curved plate behind the foramen magnum is the squama occipitalis.

[0354] Orbit: cavity in the skull to house the eyeball.

[0355] Parietal bones: The parietal bones are bones that, when joined together, form the roof and sides of the skull.

[0356] Temporal bone: The temporal bone is located at the base and sides of the skull and supports parts of the face known as the temples.

[0357] Cheekbones: The face includes two cheekbones that are located on the top and sides of the face and form the cheek ridges.

[0358] 5.8.7 Respiratory system structure Diaphragm: A layer of muscle that extends across the base of the rib cage. The diaphragm separates the thoracic cavity, which contains the heart, lungs, and ribs, from the abdominal cavity. When the diaphragm contracts, the volume of the thoracic cavity increases, drawing air into the lungs.

[0359] Larynx: The larynx, or voice box, houses the vocal cords and connects the lower part of the pharynx (hypopharynx) with the trachea.

[0360] Lung: Human respiratory system. The conducting region of the lung includes the trachea, bronchi, bronchioles, and terminal bronchioles. The respiratory region includes the respiratory bronchioles, alveolar ducts, and alveoli.

[0361] Nasal cavity: The nasal cavity (or nasal fossa) is a large air-filled space in the center of the face above and behind the nose. The nasal cavity is divided into two by a vertical fin called the nasal septum. On either side of the nasal cavity are three horizontal extensions called nasal conchae (singular "concha") or turbinates. At the front of the nasal cavity is the nose, which merges dorsally into the nasopharynx via the choanae.

[0362] Pharynx: the part of the throat located just below (inferior to) the nasal cavity and above the esophagus and larynx. The larynx is usually divided into three parts: the nasopharynx (upper pharynx) (nasal part of the pharynx), the oropharynx (mesopharynx) (oral part of the pharynx), and the laryngopharynx (lower pharynx).

[0363] 5.8.8 Materials Silicone or silicone elastomer: Synthetic rubber. In this specification, reference to silicone is a reference to liquid silicone rubber (LSR) or compression molded silicone rubber (CMSR). One form of commercially available LSR is SILASTIC (included in the line of products sold under this trademark) manufactured by Dow Corning. Another manufacturer of LSR is Wacker. Unless otherwise stated to the contrary, preferred forms of LSR have a Shore A (or Type A) indentation hardness in the range of about 35 to about 45, measured using ASTM D2240.

[0364] Polycarbonate: A generally transparent thermoplastic polymer of bisphenol A carbonate.

[0365] 5.8.9 Patient Interface Aspects Anti-Asphyxiation Valve (AAV): A component or subassembly of a mask system that reduces the risk of excessive CO2 rebreathing by the patient by venting to atmosphere in a fail-safe manner.

[0366] Elbow: A conduit that directs the axis of airflow to change direction through a predetermined angle. In one form, the angle may be approximately 90°. In other forms, the angle may be less than 90°. The conduit may have a generally circular cross section. In other forms, the conduit may have an oval or rectangular cross section.

[0367] Mask Frame: Mask frame is understood to mean the mask structure that supports the tension load between two or more connection points with the headgear. The mask frame may be a non-airtight load-bearing structure in the mask. However, some forms of mask frames may be airtight.

[0368] Headgear: Headgear is taken to mean a form of positioning and stabilizing structure adapted for use on the head. The headgear may comprise an assembly of one or more posts, straps, and reinforcements configured to position and hold a patient interface in place on a patient's face to deliver respiratory therapy. Some straps are formed from a soft, flexible, elastic material, such as a laminated composite of foam and fabric.

[0369] Membrane: Membrane is understood to mean a generally thin element that is substantially not resistant to bending but is resistant to elongation.

[0370] Plenum chamber: Mask plenum chamber is taken to mean that part of a patient interface having walls enclosing a volume of space, said volume having air therein that is pressurized above atmospheric pressure in use. An outer shell may form part of the wall of the mask plenum chamber.

[0371] Seal: The noun form ("seal") is taken to mean a structure or barrier that intentionally resists the flow of air through the interface of two surfaces. The verb form ("to seal") is taken to mean to resist the flow of air.

[0372] Shell: Shell is understood to mean a curved, two-dimensional structure having bending, tensile, and compressive stiffness, e.g., the portion of the mask that forms the curved structural wall of the mask. The shell is relatively thin compared to its overall dimensions. In some embodiments, the shell may be chamfered. Such walls are airtight, but in some embodiments, they may not be airtight.

[0373] Reinforcement: Reinforcement is taken to mean a structural component adapted to increase the bending resistance of another component in at least one direction.

[0374] Strut: A strut is understood to be a structural component adapted to increase the compressive resistance of another component in at least one direction.

[0375] Swivel: (noun) A subassembly of components configured to rotate independently about a common axis under low torque. In one form, the swivel may be configured to rotate through an angle of at least 360°. In another form, the swivel may be configured to rotate through an angle less than 360°. The subassembly of components, when used in conjunction with an air delivery conduit, comprises a matched pair of cylindrical conduits. There is little or no airflow leakage from the swivel when in use.

[0376] String: A string is understood to be a structural component adapted to resist tension.

[0377] Vent: (noun) A structure that allows the intentional flow of air from within a mask, e.g., to allow the escape of exhaled gases, or a conduit to the outside air.

[0378] 5.8.10 Terminology used in relation to patient interfaces Curvature (of a surface): A region of a surface that has a saddle shape, curving upward in one direction and downward in a different direction, is said to have negative curvature. A region of a surface that has a dome shape, curving equally in both major directions, is said to have positive curvature. A flat surface is interpreted as having zero curvature.

[0379] Soft: The quality of a material, structure, or composite that is one or more of the following: · Easily adapts to acupressure. · It is unable to maintain its shape when forced to support its own weight. -Not rigid. · Can be stretched or bent elastically with little effort.

[0380] The quality of being flexible may have an associated direction, so that a particular material, structure, or composite may be flexible in a first direction, but stiff or rigid in a second direction, for example, a second direction perpendicular to the first direction.

[0381] Elasticity: Able to deform substantially elastically within a relatively short time, such as one second, and to release substantially all of the energy when the load is removed.

[0382] Rigid: Does not easily deform in response to finger pressure and / or tensions or loads typically encountered when placing and maintaining a patient interface in sealing relationship with the entrance to a patient's airway.

[0383] Semi-rigid: means sufficiently rigid so as not to substantially distort under the mechanical forces typically applied during positive airway pressure therapy.

[0384] 5.9 Other findings A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the reproduction by any person of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.

[0385] Unless the context clearly dictates otherwise, when a range of values ​​is given, it is understood that each value between the upper and lower limits of that range, to the tenth of the unit of the lower limit, and any other stated value or value within that stated range, is included within the technology. The upper and lower limits of these intervening ranges, which may independently be included within the intervening ranges, are also included within the technology, subject to any specifically excluded limit in the stated range. When a stated range includes one or both of its limits, ranges excluding either or both of those included limits are also included within the technology.

[0386] Additionally, where one or more values ​​are set forth herein as implemented as part of the present technology, it is understood that such values ​​may be approximated unless otherwise stated, and such values ​​may be utilized to any suitable significant figure, provided that practical technical implementation permits or requires it.

[0387] Unless otherwise defined, 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 exemplary methods and materials are described herein.

[0388] Where a particular material is deemed preferred for use in constructing a component, obvious alternative materials having similar properties may be used as substitutes, and unless expressly stated to the contrary, it is understood that any and all components described herein may be, and thus may be, manufactured together or separately.

[0389] 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.

[0390] All publications mentioned herein are incorporated by reference to disclose and describe the methods and / or materials that are the subject of such publications. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein should be construed as an admission that the present technology is not entitled to antedate such publication by virtue of prior invention. Also, the dates of publication provided may be different from the actual publication dates, which may need to be independently confirmed.

[0391] The terms "comprises" and "comprising" should be interpreted as referring to elements, components, or steps in a non-exclusive manner, and thus as suggesting that a mentioned element, component, or step may be present or utilized or may be combined with other elements, components, or steps not expressly mentioned.

[0392] The subject headings used in the detailed description are included for ease of reference only and should not be used to limit the subject matter found throughout the disclosure or claims. The subject headings should not be used to limit the scope of one or more claims.

[0393] Although the technology herein has been described with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the technology. In some cases, terminology and symbols may suggest specific details that are not required to practice the technology. For example, while the terms "first" and "second" may be used, unless otherwise specified, these terms are not intended to indicate any order and may be utilized to distinguish between separate elements. Also, while process steps in a methodology may be described or illustrated in a certain order, such ordering is not required. As will be appreciated by those skilled in the art, such ordering may be changed and / or aspects may occur simultaneously or even synchronously.

[0394] It is therefore to be understood that numerous modifications may be made to the illustrated embodiments and other arrangements may be devised without departing from the spirit and scope of the present technology.

[0395] Furthermore, the present invention preferably includes the following examples. [Additional note 1] 1. A patient interface for delivering a flow of breathable gas to an entrance of a patient's airways including at least the entrances of the patient's nares, said patient interface comprising: a heat and moisture exchanger (HME) comprising at least one corrugated structure for moisture exchange, the corrugated structure comprising a plurality of corrugations, the corrugations forming a plurality of channels for permitting the flow of breathable gas through the HME along a surface of the corrugated structure; the corrugated structure retains moisture from the exhaled gas stream; A patient interface wherein the retained moisture is provided to a flow of breathing gas for humidification. [Additional note 2] 10. The patient interface of claim 1, wherein the heat and moisture exchanger (HME) is oriented such that the plurality of channels are generally parallel to a flow path of a breathable gas flow. [Additional note 3] the HME further comprising a generally flat bottom structure; 3. A patient interface according to claim 1 or claim 2, wherein the corrugated structure is engaged with the bottom structure to form a layer. [Additional note 4] each corrugation of the corrugated structure comprises an upper fold and a lower fold; 4. A patient interface according to claim 3, wherein each lower fold engages a surface of the lower end structure. [Additional note 5] 5. A patient interface as described in claim 4, wherein the layer further comprises a generally planar top structure, the upper folded portion of each corrugation engaging a surface of the top structure such that the corrugation structure is disposed between the top structure and the bottom structure to form a concertina-shaped layer. [Additional note 6] 6. A patient interface according to claim 4 or claim 5, wherein the upper end structure and / or the lower end structure are non-moisture absorbing. [Additional note 7] 7. The patient interface of claim 6, wherein the thickness of the upper end structure and / or the lower end structure is 0.03 to 0.12 mm. [Additional note 8] 8. The patient interface of claim 3, wherein the heat and moisture exchanger (HME) comprises multiple layers forming a predetermined three-dimensional shape configured to fit within a plenum chamber of the patient interface. [Additional note 9] 10. The patient interface of claim 8, wherein the plurality of layers are laser cut to form a predetermined three-dimensional shape. [Additional Note 10] 10. A patient interface according to claim 8 or claim 9, wherein the plurality of layers are stacked to form a predetermined three-dimensional shape. [Additional Note 11] 11. A patient interface according to any one of claims 8 to 10, wherein at least one of the layers comprises a different size and / or shape than the other layers. [Additional Note 12] 12. A patient interface according to any one of claims 8 to 11, wherein the predetermined three-dimensional shape comprises portions that are curved inward to avoid contact with the patient's face. [Additional Note 13] 13. A patient interface according to any one of claims 8 to 12, wherein the predetermined three-dimensional shape is an irregular shape. [Additional Note 14] The heat and moisture exchanger (HME) is 4 to 14 m 2 / m 3 14. A patient interface according to any one of claims 1 to 13, structured to have a predetermined surface area per unit volume of [Additional Note 15] 15. The patient interface of any one of claims 1 to 14, wherein the heat and moisture exchanger (HME) is structured to have a predetermined water absorption rate of 50 to 100 mm / 10 min. [Additional Note 16] 16. The patient interface of any one of claims 1 to 15, wherein the heat and moisture exchanger (HME) further comprises a biocompatible additive. [Additional Note 17] 17. The patient interface of claim 16, wherein the biocompatible additive is CaCl2. [Additional Note 18] 18. The patient interface of any one of claims 1 to 17, wherein the heat and moisture exchanger (HME) has a flow impedance of 0 to 2.5 cmH2O at a predetermined flow rate of 100 L / min. [Additional Note 19] 19. The patient interface of claim 18, wherein the flow impedance is between 0 and 1.6 cmH2O at a predetermined flow rate of 100 L / min. [Additional Note 20] 20. The patient interface of claim 19, wherein the flow impedance is reduced by reducing a density of the heat and moisture exchanger (HME) to a predetermined density. [Additional Note 21] The predetermined sheet density of the corrugated structure is 0.02 to 0.4 g / cm 3 21. A patient interface according to claim 20, wherein: [Additional Note 22] 22. A patient interface according to any one of claims 18 to 21, wherein the flow impedance is reduced by increasing the pitch of each corrugation by 1 to 4 mm. [Additional Note 23] 23. A patient interface according to any one of claims 18 to 22, wherein the flow impedance is reduced by increasing the number of channels. [Additional note 24] 24. A patient interface according to any one of claims 18 to 23, wherein the flow impedance is reduced by increasing the total volume of the plurality of channels within a flow path of a flow of breathable gas. [Additional note 25] 1. A patient interface for delivering a flow of breathable gas to an entrance of a patient's airways, the entrance including at least the entrances of the patient's nostrils, said patient interface comprising: A patient interface comprising a heat and moisture exchanger (HME) comprising multiple layers, the layers stacked into a predetermined three-dimensional shape. [Additional note 26] 26. A patient interface according to claim 25, wherein the predetermined three-dimensional shape is an irregular shape. [Additional note 27] each layer comprising a corrugated structure having a plurality of corrugations, the corrugations forming a plurality of channels for permitting the flow of breathable gas along a surface of the corrugated structure for moisture exchange; 27. A patient interface according to claim 26, wherein the corrugated structure retains moisture from the exhaled gas stream and provides the retained moisture to the breathing gas stream for humidification. [Additional note 28] the HME further comprising a generally flat bottom structure; 28. A patient interface according to any one of claims 25 to 27, wherein the corrugated structure is engaged with the bottom structure to form a layer. [Additional note 29] 30. A patient interface according to claim 28, wherein each corrugation comprises an upper fold and a lower fold, the lower fold engaging a surface of the bottom structure. [Additional note 30] 30. A patient interface as described in claim 29, wherein the layer further comprises a generally planar top structure, the upper folded portion of each corrugation engaging a surface of the top structure such that the corrugation structure is disposed between the top structure and the bottom structure to form a concertina-shaped layer. [Additional note 31] 30. The patient interface of claim 29, wherein the HME comprises multiple layers stacked vertically along a vertical axis of the HME. [Additional note 32] 32. A patient interface according to claim 30 or claim 31, wherein the upper end structure and / or the lower end structure has a weight of between 15 and 100 gsm. [Additional note 33] 1. A heat and moisture exchanger (HME) for removably engaging a patient interface for delivering a flow of breathable gas to an entrance of a patient's airways including at least the entrances of the patient's nares, the HME comprising: a rigid frame that circumferentially surrounds an outer circumferential surface of the heat and moisture exchanger (HME); The rigid frame is configured to removably engage an inner surface of a plenum chamber of the patient interface to position the HME within a flow path of a breathable gas flow. [Additional note 34] 34. The heat and moisture exchanger (HME) of claim 33, wherein the rigid frame comprises at least one engagement member for engaging an inner surface of the plenum chamber. [Additional note 35] 35. The HME of claim 34, wherein the engagement member comprises a clip for engaging an inner surface of the plenum chamber. [Additional note 36] the heat and moisture exchanger (HME) comprises at least one corrugated structure for moisture exchange, the corrugated structure comprising a plurality of corrugations, the corrugations forming a plurality of channels for allowing a flow of breathable gas along a surface of the corrugated structure for moisture exchange; the corrugated structure retains moisture from the exhaled gas stream; 36. A heat and moisture exchanger (HME) according to any one of claims 33 to 35, wherein the retained moisture is provided to a breathing gas flow for humidification. [Additional note 37] the HME further comprising a generally flat bottom structure; 37. The HME of claim 36, wherein the corrugated structure is engaged with the bottom structure to form a layer. [Additional note 38] each corrugation of the corrugated structure comprises a lower fold; 38. The HME of claim 37, wherein each lower fold engages a surface of the bottom structure. [Additional note 39] 39. The heat and moisture exchanger (HME) of claim 38, wherein the thickness of the lower end structure is 0.03 to 0.12 mm. [Additional note 40] 40. The heat and moisture exchanger (HME) of any one of claims 33 to 39, wherein the HME comprises a plurality of layers forming a predetermined three-dimensional shape configured to fit within a plenum chamber of the patient interface. [Additional note 41] 40. The heat and moisture exchanger (HME) of claim 39, wherein the plurality of layers are laser cut to form a predetermined three-dimensional shape. [Additional note 42] 42. The HME of claim 40 or claim 41, wherein the plurality of layers are stacked to form a predetermined three-dimensional shape. [Additional note 43] 43. The HME of any one of claims 40 to 42, wherein the predetermined three-dimensional shape comprises a portion that is curved inward to avoid contact with the patient's face. [Additional note 44] 44. The HME of any one of claims 40 to 43, wherein the predetermined three-dimensional shape is an irregular shape. [Additional note 45] The heat and moisture exchanger (HME) is 4 to 14 m 2 / m 3 45. The heat and moisture exchanger (HME) of any one of claims 33 to 44, structured to have a predetermined surface area per unit volume of . [Additional note 46] 46. ​​The heat and moisture exchanger (HME) of any one of claims 33 to 45, wherein the HME is structured to have a predetermined water absorption rate of 50 to 100 mm / 10 min. [Additional note 47] 47. The heat and moisture exchanger (HME) of any one of claims 33 to 46, wherein the HME further comprises a drying additive. [Additional note 48] 48. The heat and moisture exchanger (HME) of claim 47, wherein the dry additive is CaCl. [Additional note 49] 49. The heat and moisture exchanger (HME) of any one of claims 33 to 48, wherein the flow impedance of the HME is between 0 and 2.5 cmH2O at a predetermined flow rate of 100 L / min. [Additional Note 50] 50. The heat and moisture exchanger (HME) of claim 49, wherein the flow impedance is between 0 and 1.6 cmH2O at a predetermined flow rate of 100 L / min. [Additional note 51] The heat and moisture exchanger (HME) has a density of 0.02 to 0.4 g / cm 3 51. The heat and moisture exchanger (HME) of any one of claims 33 to 50, structured to have a sheet density of [Additional note 52] 52. The heat and moisture exchanger (HME) of any one of claims 34 to 51, wherein the corrugated structure has a pitch of 1 to 4 mm. [Additional note 53] 1. A patient interface for delivering a flow of breathable gas to an entrance of a patient's airways including at least the entrances of the patient's nares, said patient interface comprising: a heat and moisture exchanger (HME) configured to divide a plenum chamber of the patient interface into a first anterior chamber and a second posterior chamber, the HME being positioned within the plenum chamber to humidify a flow of breathable gas passing from the first anterior chamber to the second posterior chamber, the second posterior chamber comprising a seal-forming structure for sealing with a portion of a patient's face; A patient interface, wherein the first anterior chamber comprises an inlet for receiving a flow of breathable gas into the first anterior chamber and a vent for the exit of a flow of exhaled gas from the first anterior chamber. [Additional note 54] 54. A patient interface according to claim 53, wherein the vent is configured to regulate the outflow of exhaled gases at a substantially constant rate. [Additional note 55] The patient interface includes: a vent adapter comprising the vent and the inlet; a cushion assembly having an opening and the seal-forming structure; Further provided with 55. A patient interface according to claim 53 or claim 54, wherein the vent adapter is configured to removably engage the cushion assembly to form the plenum chamber. [Additional note 56] 56. A patient interface according to claim 55, wherein a front portion of the vent adapter forms at least one wall of the first anterior chamber. [Additional note 57] 57. A patient interface according to claim 56, wherein the vent adapter comprises a wall forming a housing portion for containing the heat and moisture exchanger (HME). [Additional note 58] 58. A patient interface according to claim 57, wherein the housing portion is configured to position the heat and moisture exchanger (HME) within the plenum chamber. [Additional note 59] 59. A patient interface according to any one of claims 53 to 58, wherein the inlet is configured to removably engage a conduit for delivering a flow of breathable gas to the inlet. [Additional note 60] 60. The patient interface of any one of claims 53 to 59, wherein the heat and moisture exchanger (HME) is configured for releasable engagement with the patient interface. [Additional note 61] 61. The patient interface of claim 60, wherein the heat and moisture exchanger (HME) comprises at least one engagement member for releasably engaging the patient interface. [Additional note 62] 62. A patient interface according to claim 61, wherein the engagement member is selected from one of the group consisting of an adhesively engageable portion, a clip, a resilient flange, a hook, or a loop. [Additional note 63] 63. A patient interface according to claim 62, wherein the engagement members are a plurality of clips. [Additional note 64] 64. A patient interface according to any one of claims 53 to 63, further comprising a frame for providing structural support to the heat and moisture exchanger (HME). [Additional note 65] 65. A patient interface as described in claim 64, wherein the frame circumferentially surrounds an outer peripheral surface of the heat and moisture exchanger (HME), and the layer is positioned within an opening extending through the frame such that a plurality of channels extend through the opening. [Additional note 66] 66. A patient interface according to claim 65, wherein the heat and moisture exchanger (HME) comprises multiple layers stacked within the opening in the frame. [Additional note 67] each layer comprising a corrugated structure for moisture exchange, the corrugated structure comprising a plurality of corrugations, the corrugations forming a plurality of channels for allowing a flow of breathable gas along a surface of the corrugated structure for moisture exchange; the corrugated structure retains moisture from the exhaled gas stream; 67. A patient interface according to claim 66, wherein the retained moisture is provided to a breathable gas flow for humidification. [Additional note 68] the frame includes an engagement member located on an outer surface of the frame; 68. A patient interface according to any one of claims 64 to 67, wherein the engagement member releasably engages an inner surface of the patient interface. [Additional note 69] 69. A patient interface according to claim 68, wherein the frame comprises a plurality of the engagement members. [Additional note 70] 70. A patient interface according to claim 69, wherein the frame further comprises a moisture retention reservoir to provide the retained moisture to the layer. [Additional note 71] 71. A patient interface according to claim 70, wherein the moisture retention reservoir is formed by a moisture absorbent material. [Additional note 72] 72. A patient interface according to claim 71, wherein the moisture absorbent material is a high density sponge. [Additional note 73] 1. A method of manufacturing a heat and moisture exchanger (HME) for humidifying a flow of breathing gas delivered by a patient interface, comprising: the heat and moisture exchanger (HME) has a desired flow impedance; corrugating at least one portion of the HME to form a plurality of channels for permitting the flow of breathable gas along a surface of the corrugated structure through the HME; adjusting the number of corrugations forming said channel to increase the flow rate of breathable gas through said channel to achieve a desired flow impedance; A method for providing the above. [Additional note 74] 1. A method of manufacturing a patient interface for delivering a flow of breathable gas to an entrance of a patient airway, comprising: the patient interface comprising a heat and moisture exchanger (HME) having a desired humidification performance for humidifying the breathable gas flow; manufacturing the patient interface; determining a volume of a plenum chamber of the patient interface for delivering a flow of breathable gas to a patient; corrugating at least one portion of the HME to form a plurality of channels for permitting the flow of breathable gas along a surface of the corrugated structure through the HME; adjusting the number of corrugations forming the channel to increase the surface area per unit volume of the HME based on the volume of the plenum chamber to obtain a desired added absolute humidity; removably or permanently securing the heat and moisture exchanger (HME) within the plenum chamber of the patient interface in a flow path of a breathable gas flow; A method for providing the above. [Additional note 75] 1. A method of manufacturing a heat and moisture exchanger (HME) having an increased surface area per unit volume to obtain a desired humidification performance for humidifying a breathing gas flow, comprising: determining a desired humidification performance; corrugating at least one portion of the HME to form a plurality of channels for permitting the flow of breathable gas along a surface of the corrugated structure through the HME; adjusting the number of corrugations forming the channel to increase the surface area per unit volume of the HME; stacking the HMEs into corrugated layers to further increase the surface area per unit volume of the HMEs to achieve a desired humidification performance; A method for providing the above. [Additional note 76] 1. A method of manufacturing a heat and moisture exchanger (HME) for humidifying a flow of breathing gas delivered by a patient interface to a desired level of humidification performance, the method comprising: determining a required humidification capacity of the heat and moisture exchanger (HME); laser cutting a plurality of channels through the heat and moisture exchanger (HME) to increase the surface area per unit volume to enhance the humidification performance of the HME; increasing the number of said channels by laser cutting until a desired humidification performance is achieved; A method for providing the above. [Explanation of symbols]

[0396] 1000 patients 3000 Patient Interface 3100 Seal forming structure 3100 Seal forming part 3110 Seal flange 3120 Support flange 3130 Cushion Assembly 3135 Cushion assembly engaging member 3200 Plenum Chamber 3210 Outer perimeter 3220 Periphery 3230 Rear Plenum Chamber 3240 Forward Plenum Chamber 3240 Rear Plenum Chamber 3250 Mask Frame 3255 Mask frame engaging member 3260 Entrance 3300 Positioning and Stabilizing Structure 3301 Strap Connector 3400 Vent 3401 Auxiliary Vent 3410 Housing 3410 Vent Adapter 3415 Vent adapter engaging member 3420 HME housing part 3430 Baffle 3440 Receiving part 3450 Mounting material 3500 Tube separation structure 3510 Swivel 3520 socket 3600 connection port 3700 Frontal Support 3800 Anti-asphyxiation valve 4000 RPT equipment 4010 Outer Housing 4012 Upper 4014 Lower 4015 Panel 4016 chassis 4018 Handle 4020 Pneumatic Block 4100 Components 4110 Air Filter 4112 Inlet Air Filter 4114 Outlet air filter 4122 Inlet muffler 4124 Exit muffler 4140 Pressure Generator 4142 Blower 4144 Motor 4170 Air Circuit 4171 Heated Air Circuit 4180 Supplemental Oxygen 4200 Electrical Components 4210 Power supply 4220 input device 4230 Central Controller 4232 Clock 4240 Therapy Device Controller 4245 Treatment device 4250 protection circuit 4260 memory 4270 Transducer 4272 Pressure Sensor 4272 Pressure Transducer 4274 Flow Transducer 4274 Flow Sensor 4276 Motor Speed ​​Transducer 4280 data communications interface 4282 Remote External Communications Network 4284 Local External Communication Network 4286 Remote External Device 4288 Local External Device 4290 output device 4292 display driver 4294 display 4300 Algorithm 4310 Pretreatment Module 4312 Pressure Compensation Algorithm 4314 Vent flow rate calculation algorithm 4316 Flow Algorithm 4318 Respiratory Flow Algorithm 4320 Treatment Engine Module 4321 Phase Determination Algorithm 4322 Waveform Determination Algorithm 4323 Ventilation Volume Determination Algorithm 4324 Algorithm 4324 Inspiratory flow limit determination 4325 Apnea / hypopnea determination 4325 Algorithm 4326 Snoring Algorithm 4327 Airway Patency Algorithm 4328 Treatment parameter determination algorithm 4330 Treatment Control Module 5000 humidifier 5002 Humidifier inlet 5004 Humidifier outlet 5006 Humidifier Base 5110 Water reservoir 5110 Humidifier Reservoir 5120 Conduction part 5130 Humidifier Reservoir Dock 5135 Lock lever 5150 Water Level Indicator 5210 Humidifier Transducer 5212 Air pressure sensor 5212 Pressure Transducer 5214 Flow Transducer 5214 Air flow sensor 5216 Temperature Sensor 5216 Temperature Transducer 5218 Humidity Sensor 5240 heating element 5250 Humidifier Controller 5251 Central Humidifier Controller 5252 Heating Element Controller 5254 Heated Air Circuit Controller 7001 HME layer 7001 Bellows-shaped layer 7001 Single Strip Layer 7002 Wave structure 7003 HME Frame 7004 HME engagement member 7005 HME retaining member 7006 Frame opening 7010 Top board structure 7010 Top structure 7012 Upper Channel 7020 Lower end structure 7020 Lower end board structure 7022 Lower Channel 7030 Waveform section 7030 Wave structure 7031 Upper bend 7050 Support membrane 7050 Flexible support membrane

Claims

1. 1. A patient interface system configured to seal and deliver a continuous positive pressure airflow relative to atmospheric pressure to an entrance of a patient's airway, including at least the patient's nares, wherein the positive pressure airflow is approximately 4 cmH above atmospheric pressure in use throughout the patient's respiratory cycle while the patient is asleep to ameliorate sleep-disordered breathing. ２ Approximately 30cmH from O ２ 1. A patient interface system configured to maintain a therapeutic pressure in the range of O2, The patient interface system comprises: a plenum chamber removably connected to a frame of the patient interface, the plenum chamber configured to be pressurized to the treatment pressure in use; a seal-forming structure connected to the plenum chamber and configured to form a seal in an area around an entrance to the patient's airways, including at least the patient's nares, the seal-forming structure being constructed from a soft, flexible, and resilient material; a positioning and stabilising structure comprising at least one strap removably connected to a frame of the patient interface, the positioning and stabilising structure configured to maintain the seal-forming structure in sealing contact with an area surrounding an entrance to the patient's airway while maintaining the therapeutic pressure at the entrance to the patient's airway; a connection port configured to connect to an air circuit; Carbon dioxide (CO ２ a gas escape vent configured to vent the patient's exhaled airflow to the ambient air to minimize rebreathing of the exhaled air; a patient interface comprising: a heat and moisture exchanger (HME) disposed in the plenum chamber, the heat and moisture exchanger (HME) comprising: a rigid frame; and a hygroscopic HME material disposed within the rigid frame, the rigid frame including at least one engaging member configured to removably engage a frame of the patient interface such that the HME is removably connectable to the patient interface; 1. A patient interface system comprising:

2. 10. The patient interface system of claim 1, wherein the rigid frame further comprises at least one retention member configured to retain the HME material within the rigid frame.

3. 3. The patient interface system of claim 2, wherein the at least one retaining member is configured to provide structural support to the rigid frame.

4. 4. A patient interface system according to claim 2 or 3, further comprising a first retaining member disposed on a front side of the rigid frame and a second retaining member disposed on a rear side of the rigid frame.

5. 5. A patient interface system according to any one of claims 1 to 4, wherein at least one engagement member is configured to releasably engage a frame of the patient interface with a snap fit.

6. 6. A patient interface system according to any one of claims 1 to 5, wherein the rigid frame further comprises at least one frame opening oriented to allow airflow and / or a patient's exhaled airflow to reach the HME material.

7. the HME material includes a plurality of channels configured to allow airflow and the patient's exhaled airflow to pass through the HME material along a flow path; 7. The patient interface system of claim 6, wherein at least one of the frame openings is aligned with the flow path such that airflow and a patient's exhaled airflow pass through the at least one frame opening during use.

8. The HME material, in use, airflow travels in a first direction from the connection port through the HME material to the patient's airway; 8. A patient interface system according to any one of claims 1 to 7, wherein the patient interface is supported such that the patient's exhaled airflow travels in a second direction opposite the first direction, from the patient's airway, through the HME material, and out through the gas outflow vent to atmosphere.

9. 10. The patient interface system of claim 8, further comprising a baffle configured to separate airflow moving in the first direction from a patient's exhaled airflow moving in a second direction.

10. A patient interface system according to any preceding claim, wherein the HME material comprises multiple layers arranged in a predetermined three-dimensional shape.

11. 11. The patient interface system of claim 10, wherein each of the plurality of layers includes a corrugated structure with a plurality of corrugations forming a plurality of channels to allow airflow along a surface of the corrugated structure for moisture exchange, the corrugated structure configured to retain moisture from the exhaled air stream and provide the retained moisture to the air stream for humidification during use.

12. 12. A patient interface system according to claim 11, wherein the heat and moisture exchanger (HME) has a plurality of channels oriented generally parallel to an airflow path.

13. A patient interface system according to any one of claims 1 to 12, wherein the HME material comprises foam.

14. A patient interface system according to any one of claims 1 to 12, wherein the HME material is made of paper.

15. 15. The patient interface system of claim 14, wherein the paper HME material includes corrugations and the paper HME material is wound in a coil.

16. A patient interface system according to any preceding claim, wherein the HME material comprises paper.

17. A patient interface system according to any preceding claim, wherein the HME material comprises foam.

18. 18. A patient interface system according to any preceding claim, further comprising an auxiliary vent located on the patient side of the plenum chamber relative to the heat and moisture exchanger (HME).

19. 1. A respiratory therapy system for providing respiratory therapy to a patient, comprising: Approximately 4cmH against atmospheric pressure when in use ２ Approximately 30cmH from O ２ a respiratory treatment device including a pressure generator configured to generate a continuous positive pressure airflow in the range of O A patient interface system according to any one of claims 1 to 18; an air circuit configured to supply the air flow from the respiratory treatment device to the patient interface system; A respiratory treatment system comprising:

20. 20. The respiratory treatment system of claim 19, wherein the respiratory treatment system does not include a humidifier.

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