Heat and moisture exchanger for patient interface

Abstract

A patient interface for supplying a flow of breathable gas to an airway of a patient may include a heat and humidity exchanger (HME). The HME may be located in the course of a flow of breathable gas. The HME may absorb heat and moisture from the patient's exhaled gases, and may heat and humidify the incoming flow of breathable gases to be supplied to the patient's airways by the heat and moisture retained in the HME.

Description

[0001] This application is a divisional application of the invention patent application with application number 202110398845.0, filed on July 29, 2014, and the invention name is “Heat and Moisture Exchanger for Patient Interface”. The invention patent application 202110398845.0 is a divisional application of the invention patent application with application number 201810454937.4, filed on July 29, 2014, and the invention name is “Heat and Moisture Exchanger for Patient Interface”. The invention patent application 201810454937.4 is a divisional application of the invention patent application with application number 201480053828.1, filed on July 29, 2014, and the invention name is “Heat and Moisture Exchanger for Patient Interface”.

[0002] 1 CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to Australian patent application number AU 2013902810 filed on 29 July 2013 and New Zealand patent application number NZ 613874 filed on 7 August 2013. Each of the above applications is incorporated herein by reference in its entirety. 2 Technical Background 2.1 Technical Field

[0006] The present technology relates to one or more of the detection, diagnosis, treatment, prevention and improvement of respiratory-related diseases. In particular, the present technology relates to medical devices or apparatuses, and their use.

[0007] 2.2 Description of related technologies

[0008] 2.2.1 Human respiratory system and its diseases

[0009] The body's respiratory system facilitates gas exchange. The nose and mouth form the entrance to the patient's airway.

[0010] The airways consist of a series of branching tubes that become narrower, shorter, and more numerous as they go 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 allowing carbon dioxide to move out of the venous blood. The trachea is divided into the right and left main bronchi, which are further divided into terminal bronchioles. The bronchi constitute conducting airways and do not participate in gas exchange. Further branching of the airways leads to respiratory bronchioles and eventually to the alveoli. The alveolar region of the lungs is where gas exchange occurs and is called the respiratory region. See "Respiratory Physiology", by John B. West, Lippincott Williams & Wilkins, 9th edition published 2011.

[0011] There is a range of respiratory disorders. Some disorders may be characterised by specific events such as apnea, hypopnea and hyperpnea.

[0012] Obstructive sleep apnea (OSA) is a form of sleep-disordered breathing (SDB) characterized by events during sleep including occlusion or obstruction of the upper airway. OSA is caused by a combination of an abnormally small upper airway and normal loss of muscle tone in the area of ​​the tongue, soft palate, and posterior oropharyngeal wall during sleep. The condition causes affected patients to stop breathing sometimes 200 to 300 times per night, with a duration of typically 30 to 120 seconds. This usually results in excessive daytime sleepiness, and this may lead to cardiovascular disease and brain damage. Although the affected person may not be aware of the problem, the syndrome is a common condition, especially in middle-aged overweight men. See U.S. Patent 4,944,310 (Sullivan).

[0013] Cheyne-Stokes respiration (CSR) is another form of sleep-disordered breathing. CSR is a disorder of the patient's respiratory controller, in which there is a rhythmic alternation of enhanced ventilation and weakened ventilation, called the CSR cycle. CSR is characterized by repeated deoxygenation and reoxygenation of arterial blood vessels. Due to this repeated lack of oxygen, CSR may be harmful. In some patients, CSR is associated with repeated awakenings from sleep, which cause multiple sleep interruptions, increase sympathetic nerve activity and increase afterload. See U.S. Patent 6,532,959 (Berthon-Jones).

[0014] Obesity hyperventilation syndrome (OHS) is defined as the combination of severe obesity and chronic hypercapnia during wakefulness in the absence of other known causes of hypoventilation. Symptoms include dyspnea, morning headaches, and excessive daytime sleepiness.

[0015] Chronic obstructive pulmonary disease (COPD) includes any of a group of lower airway diseases that have certain common features. These diseases include increased resistance to air flow, a prolonged expiratory phase of breathing, and loss of normal elasticity of the lungs. Examples of COPD are emphysema and chronic bronchitis. COPD is caused by chronic smoking (a major risk factor), occupational exposure, air pollution, and genetic factors. Symptoms include: dyspnea on exertion, chronic cough, and sputum production.

[0016] Neuromuscular disease (NMD) is a broad term, which includes many diseases and disorders that damage muscle function directly or indirectly via neuropathology via intrinsic muscle pathology. Some NMD patients are characterized by progressive muscle damage, which leads to loss of walking ability, being bound to a wheelchair, dysphagia, weakening of respiratory muscles and eventually death from respiratory failure. Neuromuscular disorders can be divided into fast progressive and slow progressive: (i) fast progressive disorder: it is characterized by muscle damage that worsens over several months and causes death within several years (such as amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD) in adolescents); (ii) variable or slow progressive disorder: it is characterized by muscle damage that worsens over several years and only moderately reduces life expectancy (such as limb girdle, facioscapulobrachial and myotonic dystrophy). Symptoms of respiratory failure in NMD include: general weakness increases, dysphagia, dyspnea during exercise and rest, fatigue, drowsiness, morning headache and inattention and mood changes.

[0017] Chest wall disease is a group of thoracic deformities that result in inadequate coupling between the respiratory muscles and the thorax. The disease is usually characterized by localized defects and has the potential for prolonged hypercapnic respiratory failure. Scoliosis and / or kyphoscoliosis may lead to severe respiratory failure. Symptoms of respiratory failure include: dyspnea on exertion, peripheral edema, orthopnea, recurrent chest infections, morning headaches, fatigue, poor sleep quality, and loss of appetite.

[0018] Some therapies have been used to treat or improve such conditions. In addition, otherwise healthy people can use such therapies to prevent respiratory diseases from occurring. However, these have some disadvantages.

[0019] 2.2.2 Therapy

[0020] Nasal continuous positive airway pressure (CPAP) therapy has been used to treat obstructive sleep apnea (OSA). The premise is that the continuous positive airway pressure acts as an inflatable splint and can prevent upper airway occlusion by pushing the soft palate and tongue forward and away from the posterior oropharyngeal wall. Treatment of OSA via nasal CPAP therapy may be voluntary, and therefore, patients may choose not to comply with the therapy if they find the equipment used to deliver such therapy to be one or more uncomfortable, difficult to use, expensive, or unsightly.

[0021] Non-invasive ventilation (NIV) provides ventilation support to the patient through the upper airway to assist the patient in complete breathing and / or maintain adequate oxygen levels in the body by performing some or all of the work of breathing. The ventilation support is provided through a patient interface. NIV has been used to treat CSR, OHS, COPD, MD and chest wall diseases. In some forms, the comfort and effectiveness of these therapies can be improved.

[0022] Non-invasive ventilation (IV) provides ventilation support to patients who are no longer able to breathe effectively on their own and may be provided using a tracheostomy tube. In some forms, the comfort and effectiveness of these therapies may be improved.

[0023] 2.2.3 Diagnosis and treatment system

[0024] These therapies can be provided by a therapeutic system or device.Systems and devices can also be used to diagnose a condition without treating it.

[0025] A therapy system may include a respiratory pressure therapy device (RPT device), an air circuit, a humidifier, a patient interface, and data management.

[0026] Another form of treatment system is a mandibular repositioning device.

[0027] 2.2.3.1 Patient interface

[0028] The patient interface can be used to connect the respiratory device to its user, for example, by providing an air flow. The air flow can be provided to the nose and / or mouth via a mask, to the mouth via a tube, or to the user's trachea via a tracheotomy tube. Depending on the therapy to be administered, the patient interface can, for example, form a seal with the patient's facial area to facilitate the delivery of gas at a pressure sufficiently different from the ambient pressure, such as a positive pressure of about 10 cm of water column, to achieve treatment. For other forms of therapy, such as delivering oxygen, the patient interface may not include a sealing portion sufficient to facilitate the delivery of a gas supply to the airway at a positive pressure of about 10 cm of water column.

[0029] There are many challenges in designing a patient interface. The face has a complex three-dimensional shape. The size and shape of the nose varies greatly between individuals. Because the head is composed of bones, cartilage, and soft tissue, different areas of the face respond differently to mechanical forces. The jaw or mandible can move relative to other bones of the skull. The entire head may move over the course of a period of respiratory therapy.

[0030] As a result of these challenges, some masks have one or more drawbacks of being conspicuous, unsightly, expensive, poorly fitting, difficult to use, and uncomfortable (especially when worn for long periods of time or when the patient is unfamiliar with the system). For example, masks designed only for pilots, masks designed as part of a personal protective device (e.g., a filtering mask), a SCUBA mask, or a mask used for the administration of anesthetics may be tolerable for their initial application, but are undesirably uncomfortable for prolonged wear, such as several hours. This discomfort may lead to reduced patient compliance with treatment. This is especially true if the mask is worn during sleep.

[0031] Nasal CPAP therapy is very effective for treating certain respiratory conditions, assuming the patient complies with the treatment. If the mask is uncomfortable or difficult to use, the patient may not comply with the treatment. Because patients are often advised to clean their masks regularly, if the mask is difficult to clean (e.g., difficult to assemble or disassemble), the patient may not clean their mask and this may affect patient compliance.

[0032] While masks used for other purposes (eg, pilots) may not be suitable for treating sleep-disordered breathing, masks designed for treating sleep-disordered breathing may be suitable for other purposes.

[0033] For these reasons, patient interfaces for delivering nasal CPAP during sleep represent a distinct field.

[0034] 2.2.3.1.1 Seal forming part

[0035] The patient interface may include a seal-forming portion. Because it is in direct contact with the patient's face, the shape and structure of the seal-forming portion may directly affect the effectiveness and comfort of the patient interface.

[0036] The features of the patient interface are described in part according to the design intent of the seal-forming portion at the joint with the face in use. In one form of patient interface, the seal-forming portion may include two sub-portions that engage with the corresponding left and right nostrils. In one form of patient interface, the seal-forming portion may include a single element that surrounds both nostrils in use. Such a single element can be designed to, for example, cover the upper lip area and the bridge of the nose area of ​​the face. In one form of patient interface, the seal-forming portion may include an element that surrounds the mouth area in use, for example by forming a seal on the lower lip area of ​​the face. In one form of patient interface, the seal-forming portion may include a single element that surrounds both nostrils and the mouth area in use. These different types of patient interfaces may be named by their manufacturers by a variety of names, including nasal masks, full-face masks, nasal pillows, nasal puffs, and oral-nasal masks.

[0037] A seal-forming portion that may be effective in one area of ​​a patient's face may not be appropriate in another area, for example because of the different shapes, structures, variability, and sensitivity areas of the patient's face. For example, a seal on a swimming goggle that covers the patient's forehead may not be appropriate for use on the patient's nose.

[0038] Certain seal forming portions may be designed for mass manufacturing so that one design fits and is comfortable and effective for many different face shapes and sizes. To the extent there is a mismatch between the shape of the patient's face and the seal forming portion of the mass manufactured patient interface, one or both must be changed in order to form a seal.

[0039] One type of seal forming portion extends around the perimeter of the patient interface and is intended to seal against the user's face when a force is applied to the patient interface so that the seal forming portion is in facing engagement with the user's face. The seal forming portion may include an air or fluid filled cushion, or a surface molded or formed from a resilient sealing element made of an elastomer such as rubber. With this type of seal forming portion, if the fit is inadequate, there will be a gap between the seal forming portion and the patient's face, and additional force will be required to force the patient interface against the patient's face in order to achieve a seal.

[0040] Another type of seal forming portion includes a flap seal of thin material that is positioned around the perimeter of the mask so as to provide a self-sealing action against the patient's face when positive pressure is applied within the mask. Similar to the previous type of seal forming portion, if the fit between the patient's face and the mask is not good, additional force may be required to form a seal, otherwise the mask may leak unintentionally. In addition, if the shape of the seal forming portion does not match the patient, it may wrinkle or bend during use, resulting in unintentional leakage.

[0041] Another type of seal-forming portion may include friction-fit elements, for example for insertion into a nostril, but some patients find these uncomfortable.

[0042] Another form of seal forming portion can utilize adhesive to realize sealing.Some patients may find it inconvenient to apply and remove adhesive to their face constantly.

[0043] A range of patient interface seal forming part technology assigned to ResMed plc is disclosed in the following patent applications: WO 1998 / 004,310; WO 2006 / 074,513; WO 2010 / 135,785.

[0044] One form of nasal pillow is found in the Adam Circuit manufactured by Puritan Bennett. Another type of nasal pillow or nasal spray is the subject of U.S. Patent No. 4,782,832 (Trimble et al.), assigned to Puritan-Bennett Corporation.

[0045] ResMed Inc. has produced the following products that include nasal pillows: SWIFT nasal pillows mask, SWIFT II nasal pillows mask, SWIFT LT nasal pillows mask, SWIFT FX nasal pillows mask and LIBERTY full face mask. The following patent applications assigned to ResMed Inc. describe nasal pillows masks: International Patent Application WO 2004 / 073778 (which describes, among other things, aspects of ResMed's SWIFT nasal pillows), U.S. Patent Application 2009 / 0044808 (which describes, among other things, aspects of ResMed's SWIFT LT nasal pillows); International Patent Applications WO 2005 / 063,328 and WO 2006 / 130,903 (which describe, among other things, aspects of ResMed's LIBERTY full face mask); International Patent Application WO 2009 / 052,560 (which describes, among other things, aspects of ResMed's SWIFT FX nasal pillows).

[0046] 2.2.3.1.2 Positioning and stabilization

[0047] The seal forming part of the patient interface for positive air pressure therapy is subjected to the corresponding force of air pressure to interrupt the seal. Therefore, various technologies have been used to position the seal forming part and to maintain the sealing relationship between the seal forming part and the appropriate part of the patient's face.

[0048] One technique is to use adhesives. See for example US patent application US2010 / 0000534. However, these can be somewhat uncomfortable.

[0049] Another technique is to use one or more straps and stabilizing ties. Many of these devices have one or more drawbacks of poor fit, bulk, discomfort, and inconvenience in use.

[0050] 2.2.3.1.3 Ventilation hole technology

[0051] Some forms of patient interface systems may include vents to allow for the discharge of exhaled carbon dioxide. The vents may allow gas to flow from an interior space of the patient interface, such as a plenum, to the exterior of the patient interface, such as to the surrounding environment. The vents may include an orifice through which gas may flow when the mask is in use. Many such vents are noisy. Others may become blocked during use and provide inadequate washout. Some vents may disturb the sleep of a bed partner 1100 of the patient 1000, such as by noise or concentrated airflow.

[0052] ResMed Ltd. has developed a number of improved mask vent technologies. See WO 1998 / 034,665, WO 2000 / 078,381, US 6,581,594, US patent application, US 2009 / 0050156 and US patent application 2009 / 0044808.

[0053] Noise table of existing masks (ISO17510-2:2007, 10cm water column 1 meter pressure)

[0054] Mask name Mask type A-weighted sound pressure level A-weighted sound pressure year (approximately)

[0055]

[0056] (*One sample only measured in CAPA mode with 10 cm water column using the test method specified in ISO3744)

[0057] The following lists the sound pressure values ​​for various objects

[0058]

[0059] 2.2.3.2 Airway Pressure Therapy (RPT) Devices

[0060] Air pressure generators are known in a range of applications, such as industrial-scale ventilation systems. However, air pressure generators for medical applications have special requirements that are not met by more common air pressure generators, such as reliability, size and weight requirements for medical devices. In addition, even devices designed for medical use may suffer from disadvantages, including one or more of comfort, noise, ease of use, effectiveness, size, weight, manufacturability, cost and reliability.

[0061] One example of a special requirement for certain RPT devices is noise.

[0062] Table of noise output levels of existing RPT devices (one sample only measured in CAPA mode at 10 cm water column using the test method specified in ISO3744).

[0063]

[0064]

[0065] One known RPT device for treating sleep-disordered breathing is the S9 Sleep Therapy System manufactured by ResMed. Another example of an RPT device is a ventilator. A ventilator such as the ResMed Stellar TM The range of adult and pediatric ventilators can provide support for invasive and non-invasive independent ventilation for some patients to treat conditions such as, but not limited to, NMD, OHS and COPD.

[0066] ResMed Elisée TM 150 ventilator and ResMed VS III TM Ventilators can provide support for invasive and non-invasive dependent ventilation suitable for adult or pediatric patients to treat some conditions. These ventilators provide volume and pressure ventilation modes with single or double limb circuits. RPT devices typically include a pressure generator, such as an electric blower or a compressed gas reservoir, and are configured to supply air flow to the patient's airway. In some cases, the air flow can be supplied to the patient's airway at a positive pressure. The outlet of the RPT device is connected to a patient interface via an air circuit, such as those described above.

[0067] 2.2.3.3 Humidifier

[0068] Delivering an unhumidified air stream may cause drying of the airways. A humidifier is used with an RPT device and a patient interface to produce humidified gas that minimizes drying of the nasal mucosa and increases patient airway comfort. Warm air applied to the facial area in and around the patient interface is generally more comfortable than cold air, except in cool climates. A range of artificial humidification devices and systems are known, however they may not meet the specialized requirements of a medical humidifier.

[0069] Medical humidifiers are used to increase the humidity and / or temperature of an air stream relative to ambient air when needed, typically where a patient may be asleep or resting (e.g., in a hospital). Thus, a medical humidifier may be small for bedside placement, and it may be configured to humidify and / or heat only the air stream delivered to the patient without humidifying and / or heating the patient's surroundings. For example, room-based systems (e.g., saunas, air conditioners, evaporative coolers) may also humidify the air inhaled by the patient, but they also humidify and / or heat the entire room, which may cause discomfort to the occupants. In addition, medical humidifiers may have more stringent safety restrictions than industrial humidifiers.

[0070] Although many medical humidifiers are known, they may have one or more disadvantages. Some medical humidifiers may provide inadequate humidification, and some are difficult or inconvenient to use by patients.

[0071] 2.2.4 Heat and Moisture Exchanger (HME)

[0072] Heat and moisture exchangers are usually made of foam, paper or a material that can act as a condensation and absorption surface. The material may carry a hygroscopic salt to improve water retention. Suitable salts include calcium chloride.

[0073] HMEs can be utilized in RPT therapy, such as in PAP therapy, to partially recover heat and moisture present in gases exhaled from the patient's airway. This heat and moisture can be retained and passively recycled to the patient as the breathable gas stream flows through the HME prior to inspiration. Thus, the use of an HME can provide the required moisture and humidity (generally recognized as >10 mg / l) to most patients during PAP therapy to minimize any adverse effects associated with PAP therapy using non-humidified ambient air, while avoiding the need for a heated humidifier system. Using an HME rather than a heated humidifier can also reduce the possibility of condensation-induced occlusions in the air delivery tubing.

[0074] The use of HMEs in PAP therapy can avoid the need for the additional power required with heated humidifiers and can reduce the need for additional associated components. This can reduce manufacturing costs and also reduce the overall size of the CPAP therapy unit.

[0075] Common issues with using HMEs in CPAP therapy relate to the ability of the HME to provide adequate heat and moisture while also minimizing flow impedance and maintaining comfortable and safe CO2 washout levels. Flow impedance can affect the patient's breathing effort (work of breathing) and also affect event (apnea, hypopnea, snoring) detection algorithms, so in many cases attempts are made to minimize it. In addition, heat and moisture losses from ventilation should also be considered to ensure that the HME functions to offset such losses.

[0076] Current configurations of HMEs in RPT therapy have shown negligible patient humidification with flow impedance and / or CO2 washout issues. For example, placing an HME unit within an elbow, around an exhaust port, or on the flow generator side of a treatment system has shown issues with impedance and / or CO2 washout, with negligible patient humidification (hygroscopic) benefits. In this configuration, the exhaust flow is the dominant flow through the HME. The exhaust flow is the flow that flows from the patient or flow generator through the HME and is discharged directly through the vent. In addition, the current design of the HME does not allow for sufficient wet exchange during patient exhalation to provide adequate humidification levels to the patient. Therefore, it is necessary to provide a superior configuration and design for use of the HME in RPT therapy (such as PAP therapy) to achieve the desired patient humidification while having acceptable impedance and CO2 washout to the therapy's flow. 3. Summary of the invention

[0077] The present technology is directed to providing medical devices for diagnosing, ameliorating, treating or preventing respiratory disease having one or more of improved comfort, cost, efficacy, ease of use and manufacturability.

[0078] A first aspect of the present technology relates to a device for use in the diagnosis, amelioration, treatment or prevention of respiratory disease.

[0079] Another aspect of the present technology relates to methods for use in the diagnosis, amelioration, treatment or prevention of respiratory disease.

[0080] A form of the present technology includes a patient interface for conveying a breathable gas flow to an airway entrance of a patient including at least a nasal entrance of the patient, the patient interface including a HME, the HME including at least one corrugated structure. The corrugated structure may include a plurality of corrugations or flutes running through the HME along the surface of the corrugated structure, wherein the corrugated structure retains moisture from an exhaled flow, and wherein the retained moisture is provided to the breathable gas flow for humidification. Moisture may include liquid and steam forms. The term "corrugation" mentioned here is also generally referred to as flutes and can be used interchangeably. A plurality of corrugations increase the surface area of ​​the corrugated structure within a fixed volume, which increases the interaction between the surface of the HME and the air exhaled from the patient. This increases the heat and moisture exchange between the patient and the HME and can ultimately improve the humidification performance of the HME in the patient interface to a desired level. In addition, the increased humidification performance allows a smaller HME to play a role and reach a desired performance level, thereby occupying a smaller volume in the patient interface. The volume occupied by the HME can affect flow impedance, affect CO2 washout and / or cause a loss of therapeutic pressure delivered to the patient during PAP therapy. Therefore, the corrugated HME material has an increased surface area for moisture exchange per unit volume so that the effect of the HME on flow impedance is reduced. In addition, the corrugations allow the breathable gas flow to be closer to the heat and moisture exchange surface of the HME, thereby providing the HME with a high surface area per unit volume, which can provide better humidification to the patient.

[0081] Another aspect of one form of the present technology is a HME wherein the HME is oriented such that a plurality of channels defined in part or in full by the corrugations of the HME are substantially parallel to the flow path of the flow of breathable gas. The orientation of the channels allows the flow of breathable gas to flow directly through the HME along the surface of the moisture exchange layer, thereby reducing the effect of the HME on flow impedance.

[0082] Another aspect of one form of the present technology is a HME, which may further include a substantially flat base structure, and wherein the corrugated structure may be joined to the base structure to form a layer. The corrugated structure may include upper and lower folded portions and each lower folded portion may be joined to the base structure. The base structure may form a supporting plane base, wherein the corrugated structure may extend vertically therefrom to form the layer. Alternatively, the layer may further include a substantially flat top structure, so that the corrugated structure is disposed between the top and the base structure to form an accordion (concertina) layer. The HME may consist of a single accordion layer. The top and base structure may provide structural support to the corrugated structure and maintain the channel formed by the corrugations, thereby allowing the flow of breathable gas to pass through the HME along the surface of the corrugated structure. The top and / or base structure may be formed of a moisture non-absorbent material. Alternatively, the top and / or base structure may be formed of the same material as the corrugated structure. The weight of the top and / or base structure may be between 15-100 g / m 2 The thickness of the top and / or the base structure affects the rigidity of the structure and thus affects its ability to provide structural support. However, there is a trade-off between maximizing the thickness of the top and / or the base structure to provide support and minimizing the thickness to reduce the impact of the HME on flow impedance. The total thickness of the HME is a key factor in changing the density and surface area per unit volume of each HME. These factors in turn affect the overall humidification performance of the HME.

[0083] In another form of the present technology, the HME can be formed by forming a plurality of layers of a predetermined three-dimensional shape suitable for fitting in the plenum chamber of the patient interface. Each layer includes a corrugated structure and at least one substantially flat base structure for support. The patient interface has different shapes and sizes. Therefore, the HME must conform to the changing internal volume of the patient interface so as to fit in its inner wall. It is difficult to shape the HME into a desired three-dimensional shape so as to fit in the patient interface with a suitable orientation. In addition, making the HME fit with the correct orientation while maintaining its humidification efficacy and reducing the influence of the HME on flow impedance adds further complexity. Generally, the materials used in the manufacture of the HME cannot be molded into the ability to produce the desired three-dimensional shape while maintaining the humidification gas flow. Therefore, forming the HME from a plurality of layers in the desired three-dimensional shape can provide flexibility while maintaining its humidification performance when forming the HME. The HME of the present technology can be formed by stacking a plurality of layers. The layers can be stacked vertically along the vertical axis of the HME. The layers of stacked HME materials make the HME formed into the desired three-dimensional shape while positioning each layer in a suitable orientation to maximize performance. The multiple channels formed by the corrugated structure in each layer can be arranged substantially vertically with the multiple channels of the corrugated structure in the adjacent layer so as to maximize the flow of breathable gas through the channels for moisture exchange. Each layer can be formed by laser cutting its part to shape the layer into a predetermined three-dimensional shape. Alternatively, the entire HME can be shaped by laser cutting the HME into a predetermined three-dimensional shape. The layers can also be formed from different sizes and / or shapes and combined to form an HME with a desired three-dimensional shape as a whole. Layers with different sizes and shapes make the HME formed into irregular shapes so as to fit in the plenum chamber of the patient interface.

[0084] In another form of the present technology, the HME can also be shaped to avoid contact with the patient's face. The HME can include an inwardly curved portion to avoid contact with the patient's nose or mouth. Positioning the HME very close to the entrance of the patient's airway ensures maximum capture of exhaled moisture. However, contact with the patient's face should be avoided or at least minimized to prevent discomfort. Therefore, it is ideal that the HME is shaped to follow the patient's facial contour so that the HME is positioned very close to the entrance of the patient's airway, while avoiding or at least minimizing contact with the patient. For example, the HME can be bent to follow and avoid the contour of the patient's face in the patient interface.

[0085] In another form of the present technology, the HME is configured to have 4-14m 2 / m 3. The surface area per unit volume is directly related to the humidification performance of the HME. That is, having a high surface area per unit volume allows the moisture exchange between the HME and the moisture source to increase to capture moisture. In addition, the HME with a high surface area per unit volume allows the volume occupied by the HME within the plenum chamber to be minimized. The volume occupied by the HME in the plenum chamber can affect the flow impedance, affecting the CO2 washout and the treatment pressure delivered to the patient. Therefore, making the HME have a high surface area per unit volume can reduce the impact of the HME on the flow impedance. A way to reduce the surface area per unit volume is to introduce corrugations in the HME. In addition, the HME can be formed with multiple layers, each of which includes a corrugated structure. The corrugated structure forms multiple channels and allows the breathable gas flow to pass through the channels along the surface of the HME. In fact, corrugations and channels increase the surface area per unit volume of the HME.

[0086] In another form of the present technology, HME is selected as having a water absorption rate between 50-100mm / 10 minutes. Faster water absorption rate allows faster water exchange through HME. This allows to improve the moisture intake of HME comprehensively and then to transport moisture to the patient faster from HME again. Water absorption rate can be changed by the amount of the available HME material in the fixed volume. In addition, water absorption rate is also affected by the surface area of ​​the HME that can be used for water exchange. Therefore, HME can be selected as the amount of the HME material in the maximized predetermined volume, while attempting to maximize the surface area per unit volume of the HME that can be used for water exchange. In addition, water absorption rate can also be increased by adding biocompatible additives such as drying additives. For example, CaCl can be added to HME.

[0087] Another aspect of one form of the present technology is directed to an HME configured to have a flow impedance of between 0-2.5 cm H2O at a predetermined flow rate of 100 L / min. The flow impedance can be between 0-1.6 cm H2O 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 a flow of breathable gas through the HME along the surface of the corrugated structure. The plurality of channels can reduce the flow resistance of the HME to the flow of breathable gas to a predetermined flow impedance level. The plurality of channels can also reduce the surface density of the corrugated structure to a predetermined surface density to reduce the flow impedance to a predetermined range. The HME can be configured to have a predetermined density of 0.02-0.4 g / cm 3At least one corrugated structure. In addition, the number of channels can be increased to a predetermined number to reduce obstruction. The flow impedance can also be reduced to a predetermined range by increasing the spacing of each corrugation or groove to between 1 and 4 mm. The spacing can be understood as representing the width of the channel defined by the corrugation. The spacing of each corrugation or groove is between 1.7-3.5 mm. The flow impedance can also be reduced to a desired range by increasing the total volume of multiple channels in the process of the breathable gas flow. It can also be advantageous to reduce the flow impedance of the HME to the exhaled gas flow to allow the level of CO2 flushed from the patient interface to be sufficient to prevent significant inhalation of CO2 that may cause respiratory discomfort. However, it is also desirable to maintain the humidification performance of the HME to the breathable gas flow to improve breathing comfort. In order to improve the humidification performance to a predetermined level, a minimum amount of HME material may be required to exist in the HME. Therefore, a balance is desired between reducing the level of flow impedance to the exhaled gas flow caused by the HME and maintaining its humidification performance.

[0088] Another aspect of one form of the present technology is directed to an HME that is removably engaged to a patient interface to deliver a flow of breathable gas to an airway entrance of a patient, the airway entrance of the patient including at least a nares entrance of the patient, wherein the HME may include a rigid frame circumferentially surrounding a circumferential surface of the HME, wherein the frame may be configured to be removably engaged to an inner surface of a plenum chamber of a patient interface to place the HME in the flow of the flow of breathable gas. The rigid HME frame may provide structural support to the HME and provide a removable engagement portion to engage within a patient interface. The rigid frame includes at least one engagement member for engaging to the inner surface of the plenum chamber of the patient interface. The engagement member may include a clip for engaging to the inner surface of the plenum chamber. Alternatively, the engagement member may be in a form selected from an adhesive engagement portion, a clip, an elastic flange, a hook, and a ring.

[0089] Another aspect of a form of the present technology is directed to an HME frame that also includes a moisture retention reservoir to retain and resupply the HME material of the HME with additional moisture. For example, the reservoir can resupply the retained moisture to the layers of the HME. In addition to retaining moisture by the HME, an additional reservoir can be provided for retaining moisture for the frame. For example, a portion of the HME frame can be formed by a water-absorbing material. This material can be a high-density sponge. Moisture can be taken away by the high-density sponge frame of the HME through capillary action and resupplied to the HME to provide additional moisture.

[0090] Another aspect of a form of the present technology is directed to a patient interface for delivering a breathable gas flow to a patient's airway entrance including at least a patient's nasal entrance, the patient interface comprising a HME configured to divide a plenum chamber of the patient interface into a first antechamber and a second rear chamber. The HME may be located in the plenum chamber to humidify the breathable gas flow flowing from the first antechamber to the second rear chamber. The second rear chamber may include a seal forming structure for sealing on a portion of the patient's face. The first antechamber may include an inlet for receiving a breathable gas flow into the first antechamber and a vent for flushing an exhaled gas flow from the first antechamber. The position of the HME in this configuration may be advantageous because it ensures that the exhaled gas from the patient flows through the HME before flushing through the vent in order to retain moisture. In addition, the HME may be placed to ensure that the breathable gas flow flowing out of the inlet flows through the HME to re-deliver the retained moisture to the patient. Alternatively, additional vents may also be placed in the rear plenum chamber to offset the CO2 accumulated in this volume. For example, in the case of a full face mask, the extra volume (i.e., dead space volume) in the rear plenum chamber compared to a smaller mask can cause unwanted excess CO2 accumulation in the space. In order to mitigate this effect, an additional vent can be placed adjacent to the patient's airway, relative to the HME on the rear side or patient side of the plenum chamber. Placing a vent on the rear side of the HME can help the HME humidify the breathable gas flow before it is delivered to the patient. In order to compensate for this discharge of humidified gas, the overall humidification performance can be maintained by increasing the ability of the HME to humidify the breathable gas flow in the plenum chamber of a predetermined volume. The inlet can be adapted to be detachably engaged to a conduit so as to deliver a breathable gas flow into the inlet. The vent can be configured to regulate the flushing of exhaled gas with a substantially constant flow rate. The patient interface can further include a vent adapter, which includes a vent and an inlet. The vent adapter can also be adapted to be detachably engaged to the remainder of the patient interface to form a plenum chamber. The vent adapter can be detachably engaged to the remainder of the patient interface by an elastic clip. The front of the vent adapter may also form at least one wall of the first antechamber. The vent adapter may include a wall formed to accommodate a housing portion of the HME. The housing portion may be configured to position the HME into the plenum chamber. The vent adapter may ensure that the vent and inlet are positioned at the front side of the HME and the inlet of the patient's airway may be positioned at the rear side of the HME during use. The patient interface may also include a cushion assembly including a hole and a seal forming structure.

[0091] Another aspect of one form of the present technology is a method of manufacturing an HME for humidifying a flow of breathable gas delivered through a patient interface, the HME having a desired flow impedance. The method includes corrugating at least a portion of the HME to form a plurality of channels to allow a flow of breathable gas through the HME and along a surface of the corrugated structure, and adjusting the number of corrugations forming the channels to increase a flow rate of the flow of breathable gas through the channels to achieve the desired flow impedance.

[0092] 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 an airway of a patient, the patient interface comprising an HME having a desired humidification performance for humidifying the flow of breathable gas. The method may further include manufacturing the patient interface; determining the volume of a plenum chamber of the patient interface for delivering the flow of breathable gas to the patient, corrugating at least a portion of the HME to form a plurality of channels to allow the flow of breathable gas through the HME and along the surface of the corrugated structure, adjusting the number of corrugations forming the channels based on the volume of the plenum chamber to increase the surface area per unit of the HME to achieve a desired greater absolute humidity, and / or removably or permanently securing the HME to the plenum chamber of the patient interface in the flow of breathable gas.

[0093] Another aspect of one form of the present technology is a method of manufacturing an HME having an increased surface area per unit volume to achieve a desired humidification performance for humidifying a flow of breathable gas, 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 a flow of breathable gas through the HME and along the surface of the corrugated structure, adjusting the number of corrugations forming 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 achieve the desired humidification performance.

[0094] Another aspect of one form of the present technology is a manufacturing method for increasing the humidification performance of a HME to humidify a flow of breathable gases delivered by a patient interface to a desired level, the method may include determining the desired humidification performance of the HME, laser cutting a plurality of channels through the HME to increase the surface area per unit volume, thereby increasing the humidification performance of the HME, and / or increasing the number of channels by laser cutting until the desired humidification performance is achieved.

[0095] Another aspect of one form of the present technology is a patient interface that is molded or otherwise configured with a clearly defined perimeter shape intended to match an intended wearer.

[0096] One aspect of one form of the present technology is a portable RPT device that can be carried by a person, such as around the person's home.

[0097] One aspect of one form of the present technology is a patient interface that can be washed in the patient's home, such as in soapy water, without the need for specialized cleaning equipment. One aspect of one form of the present technology is a humidifier canister that can be washed in the patient's home, such as in soapy water, without the need for specialized cleaning equipment.

[0098] Of course, a part of the aspects may form a sub-aspect of the present technology. In addition, a plurality of sub-aspects and / or aspects may be combined together in a variety of ways and also constitute other aspects or sub-aspects of the present technology.

[0099] Other features of the present technology will be apparent by considering the information contained in the following detailed description, abstract, drawings, and claims. 4. Description of the drawings

[0100] The present technology is illustrated by way of example and not limitation in the figures of the accompanying drawings in which like reference numerals refer to similar elements, including:

[0101] 4.1 Treatment system

[0102] Figure 1A A system is shown that includes a patient 1000 wearing a patient interface 3000, in the form of nasal pillows, receiving a supply of air at positive pressure from an RPT device 4000. Air from the RPT device is humidified in a humidifier 5000 and passed along an air circuit 4170 to the patient 1000. A bed partner 1100 is also shown.

[0103] Figure 1B A system is shown that includes a patient 1000 wearing a patient interface 3000, in the form of a nasal mask, receiving a supply of air at a positive pressure from a RPT device 4000. The air from the RPT device is humidified in a humidifier 5000 and passed along an air circuit 4170 to the patient 1000.

[0104] Figure 1C A system is shown that includes a patient 1000 wearing a patient interface 3000, in the form of a full face mask, receiving a supply of air at positive pressure from a RPT device 4000. The air from the RPT device is humidified in a humidifier 5000 and passed along an air circuit 4170 to the patient 1000.

[0105] Figure 1D Shown is a patient 1000 undergoing a polysomnography (PSG).

[0106] 4.2 Respiratory system and facial anatomy

[0107] Figure 2AAn overview of the human respiratory system is shown, including the nasal and oral cavities, larynx, vocal folds, esophagus, trachea, bronchi, lungs, alveolar sacs, heart, and diaphragm.

[0108] Figure 2B Shown is a view of the human upper airway including the nasal cavity, nasal bones, lateral nasal cartilages, greater alar cartilages, nostrils, supralabial, infralabial, larynx, hard palate, soft palate, oropharynx, tongue, epiglottis, vocal folds, esophagus, and trachea.

[0109] Figure 2C is a front view of the face with multiple surface anatomical features identified, including the superior lip, superior vermilion, inferior vermilion, inferior lip, mouth width, medial canthus, nasal wing, nasolabial fold, and corner of mouth. The superior, inferior, radially inward, and radially outward directions are also indicated.

[0110] Figure 2D It is a side view of the head with multiple surface anatomical features identified, including the brow, nasal root, nasal prominence, subnasal point, upper lip, lower lip, supramental point, nose bridge, alar ridge point, upper ear root point, and lower ear root point. It also indicates the front, back, upper, and lower directions.

[0111] Figure 2E is a further lateral view of the head. The approximate location of the Frankfort level and nasolabial angle are shown. The coronal plane is also indicated.

[0112] Figure 2F A bottom view of the nose is shown with multiple features identified, including the nasolabial folds, sublabial lip, upper vermillion, nostrils, subnasal point, columella, nasal process point, long axis of the nostrils, and sagittal plane.

[0113] Figure 2G A side view showing the surface features of the nose.

[0114] Figure 2H The subcutaneous structures of the nose are shown, including the lateral cartilage, septal cartilage, greater alar cartilage, lesser alar cartilage, sesamoid cartilage, nasal bone, epidermis, adipose tissue, frontal process of the maxilla, and fibroadipose tissue.

[0115] Fig.2I The medial anatomy of the nose is shown approximately a few millimeters from the sagittal plane to illustrate, among other things, the medial crus of the septal cartilage and the greater alar cartilage.

[0116] Figure 2J An anterior view of the skull bones is shown, including the frontal, nasal, and zygomatic bones. The nasal conchae are shown as are the maxilla and mandible.

[0117] Figure 2KA side view of the skull is shown with the outline of the surface of the head and various muscles. The following bones are shown: frontal, sphenoid, nasal, zygomatic, maxillary, mandibular, parietal, temporal, and occipital. The mental protuberance is shown. The following muscles are shown: digastric, masseter, sternocleidomastoid, and trapezius.

[0118] Figure 2L An anterolateral view of the nose is shown.

[0119] 4.3 Patient Interface

[0120] Figure 3 A patient interface in the form of a nasal mask in accordance with one form of the present technology is shown.

[0121] 4.4RPT equipment

[0122] Figure 4A A RPT device according to one form of the present technology is shown;

[0123] Figure 4B A schematic diagram of the pneumatic path of an RPT device according to one form of the present technology is shown. The upstream and downstream directions are indicated.

[0124] Figure 4C A schematic diagram showing the electrical components of an RPT device according to one aspect of the present technology.

[0125] Figure 4D A schematic diagram of an algorithm implemented in a RPT device according to one aspect of the present technology is shown. In this figure, solid arrows represent actual information flow, for example via electronic signals.

[0126] Figure 4E is a flow chart illustrating a method performed by the treatment engine module of FIG. 4d according to one aspect of the present technology.

[0127] 4.5 Humidifier

[0128] Figure 5A An isometric view of a humidifier according to one aspect of the present technology is shown.

[0129] Figure 5B An isometric view of a humidifier in accordance with one aspect of the present technology is shown, showing a humidifier reservoir 5110 removed from a humidifier reservoir dock 5130 .

[0130] Figure 5C A schematic diagram of a humidifier according to one aspect of the present technique is shown.

[0131] 4.6 Respiratory waveform

[0132] Fig. 6A A typical breathing waveform model of a person while sleeping is shown.

[0133] Figure 6B A patient is shown during non-REM sleep breathing, typically over a period of about 90 seconds.

[0134] Figure 6C A polychannel sleep recording of a patient before treatment is shown.

[0135] Fig.6D Shown are flow data for a patient while the patient was experiencing a series of total obstructive apneas.

[0136] Fig. 6E Shown is a scaled inspiratory portion of a breath when the patient is experiencing low frequency inspiratory snoring.

[0137] 4.7 Heat and Moisture Exchanger

[0138] Fig. 7A Shown is a cross-sectional view of an HME 7000 comprising a single layer 7001 in accordance with one aspect of the present technology.

[0139] Figure 7B An embodiment of a single corrugation 7030 of an HME 7000 in accordance with one aspect of the present technology is shown.

[0140] Figure 7C is a schematic diagram showing an HME 7000 including a plurality of layers 7001 stacked along vertical and horizontal axes.

[0141] Fig.7D is a diagram showing an HME under preload to compact the corrugations within a fixed volume such that the number of layers 7001 increases within the fixed volume.

[0142] Fig. 8A A corrugated structure 7002 is shown, comprising a plurality of corrugations 7030 , wherein the corrugated structure is rolled up to form the HME 7000 .

[0143] Figure 8B An embodiment of a patient interface 3000 in accordance with the present technology is shown that includes an HME 7000 positioned within a plenum chamber 3200 .

[0144] Figure 8C An embodiment of a patient interface 3000 in accordance with the present technology is shown that includes an HME 7000 positioned within a plenum chamber 3200 .

[0145] Fig.8D An embodiment of a patient interface 3000 in accordance with the present technology is shown that includes an HME 7000 positioned within a plenum chamber 3200 .

[0146] Fig. 9AAn exploded view of another patient interface 3000 in accordance with the present technology is shown, including a HME 7000 and housed within a vent adapter 3410 .

[0147] Fig. 9B An exploded view of another patient interface 3000 in accordance with the present technology is shown, including a HME 7000 and housed within a vent adapter 3410 .

[0148] Fig. 9C A top view of another embodiment of a patient interface 3000 in accordance with the present technology is shown.

[0149] Fig.9D A perspective view of another embodiment of a patient interface 3000 in accordance with the present technology is shown.

[0150] Fig.9E A rear view of another embodiment of a patient interface 3000 in accordance with the present technology is shown.

[0151] Fig.9F A side view of another embodiment of a patient interface 3000 in accordance with the present technology is shown.

[0152] Figure 9G A bottom view of another embodiment of a patient interface 3000 in accordance with the present technology is shown.

[0153] Figure 9H Shown is a bottom perspective view of another embodiment of a patient interface 3000 in accordance with the present technology.

[0154] Fig.9I A bottom perspective view of another embodiment of a patient interface 3000 in accordance with the present technology is shown.

[0155] Figure 9J A further embodiment of a patient interface 3000 according to the present technology is shown by Fig.9I A cross-sectional view taken along line 9J-9J.

[0156] Fig. 10A A front view of the HME frame 7003 of the removable HME 7000 is shown.

[0157] Fig. 10B A rear view of the HME frame 7003 of the removable HME 7000 is shown.

[0158] Fig. 10C A side view of the HME frame 7003 of the removable HME 7000 is shown.

[0159] Fig. 10D A bottom view of the HME frame 7003 of the removable HME 7000 is shown.

[0160] Fig.10E A first perspective view of the HME frame 7003 of the removable HME 7000 is shown.

[0161] Fig.10F A second perspective view of the HME frame 7003 of the removable HME 7000 is shown.

[0162] Fig.11A Yet another example of a removable HME 7000 is shown, wherein an enlarged view of layer 7001 is shown.

[0163] Fig. 11B A front view of a removable HME 7000 is shown.

[0164] Fig. 11C A rear view of the removable HME 7000 is shown.

[0165] Fig.11D A side view of a removable HME 7000 is shown.

[0166] Fig.11E A bottom view of the removable HME 7000 is shown.

[0167] Fig.11F A first perspective view of a removable HME 7000 is shown.

[0168] Fig.11G A second perspective view of a removable HME 7000 is shown.

[0169] Fig. 12A A front perspective view of the HME housing portion 3410 of the patient interface 3000 is shown.

[0170] Fig. 12B A rear perspective view of the HME housing portion 3410 of the patient interface 3000 is shown.

[0171] Fig. 12C A top perspective view of the HME housing portion 3410 of the patient interface 3000 is shown.

[0172] Fig.12D A rear view of the HME housing portion 3410 of the patient interface 3000 is shown.

[0173] Fig.13A A flow chart showing an exemplary process followed to select an appropriate heat and moisture exchanger (HME or HMX) is shown.

[0174] Fig. 13B Graph showing lung weight loss humidified with various types of humidification.

[0175] Fig. 13CSeveral embodiments of corrugation or flute configurations are shown that form corrugated structures that may be used in HMEs according to embodiments of the present technology.

[0176] Fig.13D Parameters of various exemplary corrugated structures are shown in accordance with embodiments of the present technology.

[0177] Fig.13E Shown is the Fig.13D The metrics for the parameters listed in the chart.

[0178] Fig.14A A rear view of a patient interface with an HME in accordance with one embodiment of the present technology is shown.

[0179] Fig. 14B A front perspective view of a patient interface having an HME in accordance with one embodiment of the present technology is shown.

[0180] Fig. 14C A front perspective view of a patient interface having an HME and a support membrane according to one embodiment of the present technology is shown.

[0181] Fig.14D A front view of a patient interface with an HME in accordance with one embodiment of the present technology is shown.

[0182] Fig.14E A front view of a patient interface with an HME and a support membrane according to one embodiment of the present technology is shown.

[0183] Fig.14F A side view of a patient interface with an HME on a patient strap is shown in accordance with an embodiment of the present technology.

[0184] Fig.15A A side view of a patient interface with an HME on a patient strap is shown in accordance with an embodiment of the present technology.

[0185] Fig. 15B A front view of a patient interface with an HME in accordance with one embodiment of the present technology is shown.

[0186] Fig. 15C A rear view of a patient interface with a HME and a support membrane is shown in accordance with one embodiment of the present technology.

[0187] Fig.16 A rear view of a HME and support membrane is shown according to one embodiment of the present technology.

[0188] Fig.17 The humidity increase over ambient humidity at different therapy pressures and flow rates was compared when the HME was placed in a known mask (ResMed Quattro FX).

[0189] 5. Detailed description of the technical embodiments

[0190] Before describing the present technology in more detail, it is to be understood that the technology is subject to variation and is not limited to the specific embodiments described herein. It is also to be understood that the terminology used in the disclosure herein is only for the purpose of describing the specific embodiments discussed herein and is not intended to be limiting.

[0191] Provide the following description about each embodiment that can share one or more common features and / or characteristics.It will be understood that one or more features of any one embodiment can be combined with one or more features of another embodiment or other embodiments.In addition, any single feature or the combination of features in any one embodiment can build another embodiment.

[0192] 5.1 Therapy

[0193] In one form, the present technology includes a method for treating a respiratory disease, the method comprising the step of applying positive pressure to an entrance to the airway of a patient 1000 .

[0194] In certain embodiments of the present technology, a supply of air at positive pressure is provided to the patient's nasal passages via one or both nostrils.

[0195] In certain embodiments of the present technology, mouth breathing is limited, restricted or prevented.

[0196] 5.2 Treatment system

[0197] In one form, the present technology includes an apparatus or device for treating respiratory disease. The apparatus or device may include an RPT device 4000 for supplying pressurized breathing gas, such as air, to a patient 1000 via an air circuit 4170 leading to a patient interface 3000.

[0198] 5.3 Patient Interface

[0199] A non-invasive patient interface 3000 according to one aspect of the present technology includes the following functional aspects: a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilization structure 3300, and a form of a connection port 3600 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, one physical component may provide one or more functional aspects. In use, the seal-forming structure 3100 is arranged to surround the entrance of the patient's airway so as to facilitate the supply of air under positive pressure to the airway.

[0200] 5.3.1 Sealing structure

[0201] In one form of the present technology, the seal-forming structure 3100 provides a seal-forming surface and may additionally provide a cushioning function.

[0202] The seal-forming structure 3100 in accordance with the present technology may be comprised of a soft, flexible, elastic material such as silicone.

[0203] In one form, the seal-forming structure 3100 includes a sealing flange 3110 and a support flange 3120. The sealing flange 3110 may include a relatively thin member having a thickness of less than about 1 mm, for example, a thickness of about 0.25 mm to about 0.45 mm, which extends around the perimeter 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 boundary edge 3220 of the plenum chamber 3200 and extends at least a section around the perimeter 3210. The support flange 3120 is or includes a spring-like element and is used to support the sealing flange 3110 from bending in use. In use, the sealing flange 3110 can easily respond to the system pressure in the plenum chamber 3200 acting on the bottom surface of the plenum chamber 3200 to push the sealing flange 3110 into a tight sealing engagement with the face.

[0204] In one form, the seal-forming portion of the non-invasive patient interface 3000 comprises a pair of nasal puffs or pillows, each nasal puff or pillow constructed and arranged to form a seal with a corresponding nostril of the patient's nose.

[0205] A nasal pillow according to one aspect of the present technology includes: a frustoconical body, at least a portion of which forms a seal on the underside of a patient's nose; and a handle on the underside of the frustoconical body and a flexible region connecting the frustoconical body to the handle. In addition, the structure to which the nasal pillows of the present technology are connected includes a flexible region adjacent to the base of the handle. The flexible region can act in concert to facilitate a universal joint structure that adjusts relative movement (both displacement and angle) of the frustoconical body and the structure to which the nasal pillows are connected. For example, the frustoconical body can move axially toward the structure to which the handle is connected.

[0206] In one form, the non-invasive patient interface 3000 includes a seal-forming portion that forms a seal in the upper lip region (ie, supra-lips) of the patient's face in use.

[0207] In one form, the non-invasive patient interface 3000 includes a seal-forming portion that forms a seal on the chin region of the patient's face in use.

[0208] 5.3.2 Pressurized chamber

[0209] The plenum chamber 3200 may have a perimeter 3210 shaped to complement the surface contours of a typical person's face in the area where a seal will be formed in use. In use, the boundary edge 3220 of the plenum chamber 3200 is placed in close proximity to the adjacent facial surface. Actual contact with the face is provided by the seal-forming structure 3100. The seal-forming structure 3100 extends around the entire perimeter 3210 of the plenum chamber 3200 in use.

[0210] 5.3.3 Positioning and stabilizing the structure

[0211] The seal-forming portion 3100 of a patient interface 3000 of the present technology is held in a sealed position by a positioning and stabilising structure 3300 during use.

[0212] 5.3.4 Ventilation holes

[0213] In one form, the patient interface 3000 includes a vent 3400 constructed and arranged to allow exhaled carbon dioxide washout.

[0214] One form of vent 3400 according to the present technology includes a plurality of holes, such as about 20 to about 80 holes, or about 40 to about 60 holes, or about 45 to about 55 holes.

[0215] The vent 3400 is located in the plenum chamber 3200. Alternatively, the vent 3400 is located in a decoupling structure 3500, such as a swivel 3510.

[0216] 5.3.5 Decoupling structure

[0217] In one form, the patient interface 3000 includes at least one decoupling structure 3500 , such as a swivel 3510 or a ball and socket 3520 .

[0218] 5.3.6 Connection Port

[0219] The connection port 3600 allows connection to the air circuit 4170 .

[0220] 5.3.7 Forehead support

[0221] In one form, the patient interface 3000 includes a forehead support 3700 .

[0222] 5.3.8 Anti-suffocation valve

[0223] In one form, the patient interface 3000 includes an anti-asphyxia valve 3800 .

[0224] 5.3.9 Ports

[0225] In one form of the present technology, the patient interface 3000 includes one or more ports that provide access to the volume within the plenum chamber 3200. In one form, this allows a clinician to assist in the provision of oxygen. In one form, this allows direct measurement of properties of the gas within the plenum chamber 3200, such as gas pressure.

[0226] 5.4RPT equipment

[0227] The RPT device 4000 according to one aspect of the present technology includes mechanical and pneumatic components 4100, electronic components 4200 and is configured to execute one or more algorithms 4300. The RPT device can have an outer housing 4010 that can be formed in two parts, an upper portion 4012, and a lower portion 4014. In addition, the outer housing 4010 can include one or more panels 4015. The RPT device 4000 includes a chassis 4016 that supports one or more internal components of the RPT device 4000. The RPT device 4000 can include a handle 4018.

[0228] The pneumatic path of the RPT device 4000 can include one or more air path items, such as an inlet air filter 4112, an inlet muffler 4122, a pressure generator 4140 (e.g., a blower 4142) capable of supplying air under positive pressure, an outlet muffler 4124, and one or more transducers 4270, such as a pressure sensor 4272 and a flow sensor 4274.

[0229] One or more air path items may be located within a removable unitary structure that will be 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 may be supported by or formed as part of a chassis 4016.

[0230] 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 electronic components 4200 may be mounted on a single printed circuit board assembly (PCBA) 4202. In an alternative form, the RPT device 4000 may include more than one PCBA 4202.

[0231] 5.4.1 Mechanical and pneumatic components of RPT equipment

[0232] The RPT device may include one or more of the following components in one integral unit. In an alternative form, one or more of the following components may be arranged as separate units.

[0233] 5.4.1.1 Air filter

[0234] An RPT device according to one form of the present technology may include an air filter 4110, or multiple air filters 4110.

[0235] In one form, the inlet air filter 4112 is positioned at the beginning of the pneumatic path upstream of the pressure generator 4140. Figure 4B .

[0236] In one form, an outlet air filter 4114, such as an antimicrobial filter, is positioned between the outlet of the pneumatic block 4020 and the patient interface 3000. Figure 4B .

[0237] 5.4.1.2 Silencer

[0238] In one form of the present technology, the inlet muffler 4122 is positioned upstream of the pneumatic path of the pressure generator 4140. Figure 4B .

[0239] In one form of the present technology, the outlet muffler 4124 is positioned in the pneumatic path between the pressure generator 4140 and the patient interface 3000. Figure 4B .

[0240] 5.4.1.3 Pressure generator

[0241] In one form of the present technology, the pressure generator 4140 for generating an air flow or air supply at a positive pressure is a controllable blower 4142. For example, the blower 4142 may include a brushless DC motor 4144 having one or more propellers housed in a volute. The blower may be capable of delivering air supply at a positive pressure ranging from about 4 cm water column to about 20 cm water column at a rate of, for example, up to about 120 liters per minute, or in other forms of air supply up to about 30 cm water column. The blower may be described in any of the following patents or patent applications, the contents of which are incorporated herein in their entirety: U.S. Patent No. 7,866,944; U.S. Patent No. 8,638,014; U.S. Patent No. 8,636,479 and PCT Patent Application Publication No. WO 2013 / 020167.

[0242] The pressure generator 4140 is under the control of the treatment device controller 4240.

[0243] In other forms, the 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.

[0244] 5.4.1.4 Converter

[0245] The transducer may be internal to the RPT device, or external to the RPT device. An external transducer may be located, for example, on or form part of an air circuit (e.g., a patient interface). An external transducer may be in the form of a non-contact sensor, such as a Doppler radar motion sensor that transmits or transfers data to the RPT device.

[0246] 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 properties such as flow rate, pressure or temperature at that point in the pneumatic path.

[0247] In one form of the present technology, one or more transducers 4270 may be located proximate to the patient interface 3000 .

[0248] In one form, the signal from the converter 4270 may be filtered, for example by a low pass, high pass or band pass filter.

[0249] 5.4.1.4.1 Flow converter

[0250] A flow transducer 4274 according to the present technology may be based on a differential pressure transducer, such as, for example, SENSIRION's SDP600 series differential pressure transducer.

[0251] In one form, a signal representing flow rate, such as total flow Qt from flow transducer 4274, is received by the central controller 4230.

[0252] 5.4.1.4.2 Pressure transducer

[0253] 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 from General Electric.

[0254] In one form, a signal from the pressure transducer 4272 is received by the central controller 4230 .

[0255] 5.4.1.4.3 Motor speed converter

[0256] In one form of the present technology, a motor speed converter 4276 is used to determine the rotational speed of the motor 4144 and / or the blower 4142. A motor speed signal from the motor speed converter 4276 may be provided to the treatment device controller 4240. The motor speed converter 4276 may be, for example, a speed sensor such as a Hall effect sensor.

[0257] 5.4.1.5 Anti-spill back valve

[0258] In one form of the present technology, an anti-overflow check valve is located between the humidifier 5000 and the pneumatic block 4020. The anti-overflow check valve can be constructed and arranged to reduce the risk that water will flow back up from the humidifier 5000, for example to the motor 4144.

[0259] 5.4.1.6 Air circuit

[0260] The air circuit 4170 according to one aspect of the present technology is a conduit or tube constructed and arranged to allow air flow between two components, such as the pneumatic block 4020 and the patient interface 3000, in use.

[0261] In particular, the air circuit 4170 can be fluidly connected to the outlet of the pneumatic block and the patient interface. The air circuit can be referred to as an air delivery tube. In some cases, there can be separate circuit limbs for inspiration and exhalation. In other cases, a single limb is used.

[0262] 5.4.1.7 Oxygen delivery

[0263] In one form of the present technology, supplemental oxygen 4180 is delivered to one or more points in the pneumatic pathway, such as upstream of the pneumatic block 4020 , to the air circuit 4170 and / or the patient interface 3000 .

[0264] 5.4.2 RPT equipment electrical components

[0265] 5.4.2.1 Power supply

[0266] The power source 4210 may be located inside or outside the housing 4010 of the RPT device 4000 .

[0267] 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.

[0268] 5.4.2.2 Input Devices

[0269] 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 software devices accessed through a touch screen. In one form, the buttons, switches, or dials may be physically connected to the external housing 4010, or in another form, may be in wireless communication with a receiver that is electrically connected to a central controller 4230.

[0270] In one form, input device 4220 may be constructed and arranged to allow a person to select values ​​and / or menu options.

[0271] 5.4.2.3 Central Controller

[0272] In one form of the present technology, the central controller 4230 is one or more processors suitable for controlling the RPT device 4000.

[0273] Suitable processors may include x86 INTEL processors, processors based on the ARM Cortex-M processor from ARM Holdings, such as the STM32 series of microcontrollers from ST MICROELECTRONIC. In some alternative forms of the present technology, 32-bit RISC CPUs, such as the STR9 series of microcontrollers from ST MICROELECTRONICS, or 16-bit RISC CPUs, such as processors from the MSP430 microcontroller family, manufactured by TEXAS INSTRUMENTS, may also be suitable.

[0274] In one form of the present technology, the central controller 4230 is a dedicated electronic circuit.

[0275] In one form, the central controller 4230 is an application specific integrated circuit. In another form, the central controller 4230 includes discrete electronic components.

[0276] The central controller 4230 may be configured to receive input signals from one or more transducers 4270 , and one or more input devices 4220 .

[0277] The central controller 4230 may be configured to provide output signal(s) to one or more output devices 4290 , a therapy device controller 4240 , a data communications interface 4280 , and a humidifier controller 5250 .

[0278] In some forms of the present technology, the central controller 4230 is configured to implement one or more methods described herein, such as one or more algorithms 4300 represented as a computer program stored in a non-transitory computer-readable storage medium such as a 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 methods may be implemented by a remotely located device. For example, the remotely located device may determine control settings for the ventilator or detect breathing-related events by analyzing stored data such as from any of the sensors described herein.

[0279] 5.4.2.4 Clock

[0280] The RPT device 4000 may include a clock 4232 connected to a central controller 4230 .

[0281] 5.4.2.5 Therapeutic equipment controller

[0282] In one form of the present technology, the treatment device controller 4240 is a control module 4330 that forms part of the algorithm 4300 executed by the central controller 4230.

[0283] In one form of the present technology, the treatment 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.

[0284] 5.4.2.6 Protection circuit

[0285] One or more protection circuits 4250 in accordance with the present technology may include electrical protection circuits, temperature and / or pressure safety circuits.

[0286] 5.4.2.7 Memory

[0287] According to one form of the present technology, the RPT device 4000 includes memory 4260, for example, 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.

[0288] Memory 4260 may be located on PCBA 4202. Memory 4260 may be in the form of EEPROM or NAND flash memory.

[0289] Additionally or alternatively, the RPT device 4000 includes a removable form of memory 4260, such as a memory card made in accordance with the Secure Digital (SD) standard.

[0290] 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 expressing one or more of the methods described herein, such as one or more algorithms 4300 .

[0291] 5.4.2.8 Data Communication System

[0292] In one form of the present technology, a data communication interface 4280 is provided and connected to the central controller 4230. The data communication interface 4280 may be connected to a remote external communication network 4282 and / or a local external communication network 4284. The remote external communication network 4282 may be connected to a remote external device 4286. The local external communication network 4284 may be connected to a local external device 4288.

[0293] In one form, the data communications interface 4280 is part of the central controller 4230. In another form, the data communications interface 4280 is separate from the central controller 4230 and may include an integrated circuit or processor.

[0294] In one form, the remote external communication network 4282 is the Internet. The data communication interface 4280 may use wired communication (eg, via Ethernet or fiber optics) or wireless protocols (eg, CDMA, GSM, LTE) to connect to the Internet.

[0295] In one form, the local external communications network 4284 utilizes one or more communications standards, such as Bluetooth or consumer infrared protocols.

[0296] In one form, remote external device 4286 is one or more computers, such as a group of network computers. In one form, remote external device 4286 can be a virtual computer, rather than a physical computer. In both cases, such remote external device 4286 can be accessed by appropriate authorized persons such as clinicians.

[0297] The local external device 4288 may be a personal computer, a mobile phone, a tablet computer, or a remote control.

[0298] 5.4.2.9 Output devices including optional displays and alarms

[0299] Output devices 4290 according to the present technology may take the form of one or more visual, auditory, and tactile units.The visual display may be a liquid crystal display (LCD) or a light emitting diode (LED) display.

[0300] 5.4.2.9.1 Display Driver

[0301] The display driver 4292 receives as input characters, symbols, or images for display on the display 4294 and converts them into commands that cause the display 4294 to display those characters, symbols, or images.

[0302] 5.4.2.9.2 Display

[0303] The display 4294 is configured to visually display characters, symbols, or images in response to commands received from the display driver 4292. For example, the display 4294 may be an eight-segment display, in which case the display driver 4292 converts each character or symbol, such as the number "0," into eight logic signals indicating whether the eight corresponding segments are activated to display the particular character or symbol.

[0304] 5.4.3RPT device algorithm

[0305] 5.4.3.1 Preprocessing Module

[0306] A pre-processing module 4310 according to one form of the present technology receives as input a signal from a transducer 4270, such as a flow transducer 4274 or a pressure transducer 4272, and performs one or more processing steps to calculate one or more output values ​​to be used as input to another module, such as a treatment engine module 4320.

[0307] In one form of the present technology, the output values ​​include the interface or mask pressure Pm, the respiratory flow Qr, and the unintentional leakage flow Ql.

[0308] In various forms of the present technology, the pre-processing module 4310 includes one or more of the following algorithms: pressure compensation 4312, ventilation flow 4314 (e.g., intentional leak), leak flow 4316 (e.g., unintentional leak), and respiratory flow 4318.

[0309] 5.4.3.1.1 Pressure compensation

[0310] In one form of the present technology, the pressure compensation algorithm 4312 receives as 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 air circuit 4170 and provides as output an estimated pressure Pm in the patient interface 3000.

[0311] 5.4.3.1.2 Ventilation flow

[0312] In one form of the present technology, the ventilation flow calculation algorithm 4314 receives as input an estimated pressure Pm in the patient interface 3000 and estimates the ventilation flow Qv of air from the vent 3400 in the patient interface 3000 .

[0313] 5.4.3.1.3 Leakage flow

[0314] In one form of the present technology, the leak flow algorithm 4316 receives as input a total flow Qt and a ventilation flow Qv, and provides as output an estimate of an unintentional leak, i.e., a leak flow Ql, by calculating the average of the difference between the total flow Qt and the ventilation flow Qv over a period long enough to include several breathing cycles, e.g., about 10 seconds.

[0315] In one form, the leak flow algorithm 4316 receives as input the total flow Qt, the ventilation flow Qv and the estimated pressure Pm in the patient interface 3000, and provides as output a leak flow Q1 by calculating the leak conductance, and determines the leak flow Q1 as a function of the leak conductance and the pressure Pm. The leak conductance can be calculated as the quotient of the low-pass filtered non-ventilation flow equal to the difference between the total flow Qt and the leakage flow Qv, and the low-pass filtered square root of the pressure Pm, where the low-pass filter time constant has a value long enough to include several breathing cycles, for example, about 10 seconds.

[0316] 5.4.3.1.4 Respiratory flow

[0317] In one form of the present technology, the respiratory flow algorithm 4318 receives as input the total flow Qt, ventilation flow Qv and leak flow Ql, and estimates the air respiratory flow Qr to the patient by subtracting the ventilation flow Qv and leak flow Ql from the total flow Qt.

[0318] 5.4.3.2 Treatment Engine Module

[0319] In one form of the present technology, therapy engine module 4320 receives as input one or more pressures Pm in patient interface 3000, and respiratory flow Qr of air to the patient, and provides as output one or more therapy parameters.

[0320] In one form of the present technology, the therapy parameter is the CPAP treatment pressure Pt.

[0321] In one form of the present technology, the therapy parameters are one or more of pressure support level, and target ventilation.

[0322] In various forms, the therapy engine module 4320 includes one or more of the following algorithms: phase determination 4321, waveform determination 4322, ventilation determination 4323, inspiratory flow limitation determination 4324, apnea / hypopnea determination 4325, snoring determination 4326, airway patency determination 4327 and therapy parameter determination 4328.

[0323] 5.4.3.2.1 Phase determination

[0324] In one form of the present technology, the RPT device 4000 is not phase determined.

[0325] 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 a phase Φ of a respiratory cycle of the patient 1000 .

[0326] In one form, the phase output is a discrete variable of a value of inspiration or expiration. In one implementation of this form, the phase Φ is determined to have a discrete value of inspiration when the respiratory flow Qr has a positive value exceeding a positive threshold, and the phase Φ is determined to have a discrete value of expiration when the respiratory flow Qr has a value more negative than a negative threshold. By convention in this implementation, the phase value during inspiration can be set to 0, while the phase value during expiration can be set to 1.

[0327] In one form, the phase output is a discrete variable having a value of one of inspiration, mid-inspiratory pause, and expiration.

[0328] In one form, the phase output is a continuous variable, for example changing from 0 to 1, or from 0 to 2π radians.

[0329] 5.4.3.2.2 Waveform determination

[0330] In one form of the present technology, the therapy engine module 4320 provides a substantially constant treatment pressure throughout the patient's breathing cycle.

[0331] In one form of the present technology, the therapy engine module 4320 provides a treatment pressure that varies during the respiratory cycle based on a pressure versus phase waveform.

[0332] In one form of the present technology, the waveform determination algorithm 4322 provides as an output a pressure-phase waveform P(Φ). The pressure-phase waveform P(Φ) may take values ​​between 0 and 1.

[0333] The predetermined waveform P(Φ) may be provided as a look-up table of values ​​P as a function of the phase value Φ. The predetermined waveform P(Φ) may alternatively be provided as one or more parameters characterizing the waveform P(Φ) according to a predetermined parameter description.

[0334] In one form, the waveform remains at an approximately constant level for all phase values.

[0335] In one form, the waveform is a square wave having a constant higher value for some phase values ​​and a constant lower level for other phase values. In this form, the parameter returned may be a threshold value for the phase above which the waveform rises from a lower level to a higher level.

[0336] In one form, the waveform P(Φ) has two exponential parts, an exponential rise according to one time constant for phase values ​​up to a threshold, and an exponential decay for phase values ​​above the threshold. In this form, the returned parameters may be the two time constants and the threshold.

[0337] 5.4.3.2.3 Ventilation determination

[0338] In one form of the present technology, the ventilation determination algorithm 4323 receives as input the respiratory flow Qr and determines a measure Vent that represents the patient's ventilation.

[0339] In one form, the ventilation determination algorithm 4323 determines the current value of the patient's ventilation, Vent, as the semi-low-pass filtered absolute value of the respiratory flow Qr.

[0340] 5.4.3.2.4 Determining inspiratory flow limitation

[0341] In one form of the present technology, the central controller 4230 executes one or more algorithms 4324 for detecting inspiratory flow limitation.

[0342] In one form, the algorithm 4324 receives as input a respiratory flow signal Qr and provides as output a measure of the degree to which the inspiratory portion of the breath exhibits inspiratory flow limitation.

[0343] In one form of the present technology, the inspiratory portion of each breath is determined by a zero crossing detector. A number of evenly spaced points (e.g., 65) representing time points are interpolated along the inspiratory flow-time curve for each breath by an interpolator. The curve described by the points is then scaled by a scaler to have a uniform length (duration / cycle) and uniform area to remove the effects of changing respiratory rate and depth. The scaled breaths are then compared in a comparator to a pre-stored template representing a normal unobstructed breath, similar to Fig. 6A t is the inspiratory portion of the breath shown in . Breaths that deviate from this template by more than a specified threshold (usually 1 scaled unit) at any time during inspiration, such as those caused by coughing, sighing, swallowing, and hiccups, are rejected as determined by the test element. For data that are not rejected, the moving average of the first such scaled point is calculated by the central controller 4230 for the previous several inspiratory events. This process is repeated for the same inspiratory event for the second such point, and so on. Thus, for example, 65 scaled data points are generated by the central controller 4230 and represent the moving average of the aforementioned several inspiratory events, such as three events. The moving average of the continuously updated values ​​of (e.g., 65) points is referred to as the "scaled flow" hereinafter, designated as Qs(t). Alternatively, a single inspiratory event can be used instead of a moving average.

[0344] Based on the scaled flow, two shape factors relevant to the determination of partial blockage can be calculated.

[0345] Shape Factor 1 is the ratio of the average of the middle (e.g., 32) scaled flow points to the average of all (e.g., 65) scaled flow points. In the case where this ratio exceeds unity, the breathing is considered normal. In the case where the ratio is unity or less, the breathing is considered obstructed. A ratio of about 1.17 is considered the threshold between partial obstruction and unobstructed breathing and corresponds to a degree of obstruction that allows adequate oxygenation to be maintained for an average user.

[0346] Shape Factor 2 is calculated as the RMS deviation from unit scaled flow using the middle (e.g., 32) points. An RMS deviation of about 0.2 units is considered normal. An RMS deviation of zero is considered a completely flow-restricted breath. The closer the RMS deviation is to zero, the more flow-restricted the breath will be considered.

[0347] Shape factors 1 and 2 may be used as alternatives or in combination. In other forms of the present technology, the number of sampling points, breaths and intermediate points may be different from those described above. Furthermore, the thresholds may be different from those described.

[0348] 5.4.3.2.5 Identification of apnea and hypopnea

[0349] In one form of the present technology, the central controller 4230 executes one or more algorithms 4325 in order to determine the presence of apnea and / or hypopnea.

[0350] The one or more algorithms 4325 may receive as input the respiratory flow signal Qr and provide as output a flag indicating that an apnea or hypopnea has been detected.

[0351] In one form, apnea may be detected when the function of respiratory flow Qr falls below a flow threshold for a predetermined period of time. The function may determine a maximum flow, a relatively short-term average flow, or a flow intermediate between a relatively short-term average flow and a maximum flow, such as an RMS flow. The flow threshold may be a relatively long-term measure of flow.

[0352] In one form, hypopnea may be detected when the function of respiratory flow Qr falls below a second flow threshold for a predetermined period of time. The function may determine a maximum flow, a relatively short-term average flow, or a flow intermediate between a relatively short-term average flow and a maximum flow, such as an RMS flow. The second flow threshold may be a relatively long-term flow measure. The second flow threshold is greater than a flow threshold for detecting apnea.

[0353] 5.4.3.2.6 Determination of snoring

[0354] In one form of the present technology, the central controller 4230 executes one or more snoring algorithms 4326 for detecting snoring.

[0355] In one form, the snoring algorithm 4326 receives as input the respiratory flow signal Qr and provides as output a measure of the extent to which snoring is present.

[0356] Algorithm 4326 may include the step of determining the strength of the flow signal in the range of 30-300 Hz. In addition, algorithm 4326 may include the step of filtering the respiratory flow signal Qr to reduce background noise, such as the sound of airflow in the system from a blower.

[0357] 5.4.3.2.7 Ensure airway patency

[0358] In one form of the present technology, the central controller 4230 executes one or more algorithms 4327 for determining airway patency.

[0359] 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 and about 3 Hz. The presence of a peak within this frequency range is considered to indicate a patent airway. The absence of a peak is considered to indicate a closed airway.

[0360] In one form, the frequency range within which the peak is sought is the frequency of a small forced oscillation at the process pressure Pt. In one implementation, the frequency of the forced oscillation is 2 Hz and the amplitude is about 1 cm of water column.

[0361] In one form, the airway patency algorithm 4327 receives as input the respiratory flow signal Qr and determines the presence or absence of a cardiogenic signal. The absence of a cardiogenic signal is considered to indicate an airway closure.

[0362] 5.4.3.2.8 Determine treatment parameters

[0363] In one form of the present technology, the central controller 4230 executes one or more algorithms 4328 for determining one or more treatment parameters using values ​​returned by one or more other algorithms in the treatment engine module 4320.

[0364] 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

[0365] Pt=AP(Φ)+P0 (1)

[0366] in:

[0367] A is pressure support,

[0368] P(Φ) is the value of the pressure-phase waveform at the current phase value Φ (in the range 0 to 1),

[0369] P0 is the base pressure.

[0370] Various treatments may be defined based on the values ​​of the parameters A and P0. In some implementations of this form of the present technology, the pressure support A is constantly zero, so that the treatment pressure Pt is constantly equal to the base pressure P0 throughout the breathing cycle. Such implementations are generally referred to under the heading of CPAP therapy.

[0371] The base pressure P0 can be a constant value that is specified and / or manually input into the PAP device 4000. This alternative is sometimes referred to as constant CPAP therapy. Alternatively, the base pressure P0 can be continuously calculated as a function of an index or measure of one or more sleep disordered respiratory events such as flow limitation, apnea, hypopnea, patency, and snoring returned by various algorithms in the treatment engine module 4320. This alternative is sometimes referred to as APAP therapy.

[0372] In other implementations of this form of positive pressure ventilation, the pressure support A is non-zero. In some such implementations, where the RPT device 4000 acts as a servo ventilator, the treatment parameter determination algorithm 4328 takes as input the current ventilation measure Vent and the target ventilation value Vtgt and calculates the value of the pressure support A so that the current ventilation measure Vent approaches the target ventilation value Vtgt. In such an implementation, the pressure-phase waveform P(Φ) is configured so as to reach a higher value during the inspiratory portion of the breathing cycle and a lower value during the expiratory portion of the breathing cycle.

[0373] In such an implementation, the therapy parameter determination algorithm 4328 may apply a continuous control method to calculate the pressure support A. One such continuous control method is proportional-integral (PI) control, according to which the pressure support is calculated as:

[0374] A=G∫(Vent-Vtgt)dt (2)

[0375] Where G is the gain of the PI control.

[0376] Other continuous control methods that may be applied by the therapy parameter determination algorithm 4328 include proportional (P), proportional-derivative (PD), and proportional-integral-derivative (PID).

[0377] Other control methods, referred to as discrete control methods, return a pressure support A that is one of a discrete set of predetermined values.

[0378] Figure 4E45 is a flow chart illustrating a method 4500 implemented by the central controller 4230 as one implementation of the algorithm 4328. The method 4500 begins at step 4520, in which the central controller 4230 compares the measure of the presence of an apnea / hypopnea to a first threshold value, and determines whether the measure of the presence of an apnea / hypopnea exceeds the first threshold value for a predetermined period of time, indicating that an apnea / hypopnea is occurring. If so, the method 4500 proceeds to step 4540; otherwise, the method 4500 proceeds to step 4530. At step 4540, the central controller 4230 compares the measure of airway patency to a second threshold value. If the measure of airway patency exceeds the second threshold value, indicating that the airway is patent, the detected apnea / hypopnea is considered central and the method 4500 proceeds to step 4560; otherwise, the apnea / hypopnea is considered obstructive and the method 4500 proceeds to step 4550.

[0379] At step 4530, central controller 4230 compares the measured value of flow limitation to a third threshold. If the measured value of flow limitation exceeds the third threshold, indicating inspiratory flow limitation, method 4500 proceeds to step 4550; otherwise, method 4500 proceeds to step 4560.

[0380] At step 4550, the central controller 4230 increases the process pressure Pt by a predetermined pressure increment ΔP, assuming that the increased process pressure Pt will 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.

[0381] In step 4560, the central controller 4230 reduces the process pressure Pt by a decrement, assuming that the reduced process pressure Pt will not be below the lower limit Pmin. The method 4500 then returns to step 4520. In one implementation, the decrement is proportional to the value of Pt-Pmin, so that the reduction of Pt to the lower limit Pmin is exponential in the absence of any detected event. In one implementation, the constant of proportionality is set so that the time constant τ of the exponential decrease of Pt is 60 minutes, and the lower limit Pmin is 4cmH2O. In other implementations, the time constant τ can be as low as 1 minute and as high as 300 minutes, or as low as 5 minutes and as high as 180 minutes. Optionally, the decrement of Pt can be predetermined, so the reduction of Pt to the lower limit Pmin is linear in the absence of any detected event.

[0382] 5.4.3.3 Control Module

[0383] The therapy control module 4330 according to 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 based on the therapy parameters.

[0384] In one form of the present technology, the therapy parameter is a treatment pressure Pt, and the therapy control module 4330 controls the therapy device 4245 to deliver a gas flow with a mask pressure Pm at the patient interface 3000 equal to the treatment pressure Pt.

[0385] 5.4.3.4 Detecting Fault Conditions

[0386] In one form of the present technology, the central controller 4230 performs one or more methods for detecting fault conditions. The fault conditions detected by the one or more methods may include at least one of the following:

[0387] Power failure (no power or insufficient power)

[0388] Converter fault detection

[0389] The presence of the part is not detected

[0390] Operating parameters are outside the recommended range (such as pressure, flow, temperature, PaO2)

[0391] The test alarm does not produce a detectable alarm signal.

[0392] When a fault condition is detected, the corresponding algorithm indicates the presence of the fault by one or more of the following:

[0393] Activate audible, visual and / or motion (e.g., vibration) alarms

[0394] Send messages to external devices

[0395] Recording events

[0396] 5.5 Humidifier

[0397] 5.5.1 Humidifier Overview

[0398] In one form of the present technology, a humidifier 5000 (e.g., Figure 5A ) to change the absolute humidity of the air or gas for delivery to the patient relative to the ambient air. Typically, the humidifier 5000 is used to increase the absolute humidity and increase the temperature of the air flow (relative to the ambient air) before delivery to the patient's airway.

[0399] The humidifier 5000 may include a humidifier reservoir 5110, a humidifier inlet 5002 for receiving an air flow, and a humidifier outlet 5004 for delivering a humidified air flow. Figure 5A and Figure 5B As shown, the inlet and outlet of the humidifier reservoir 5110 can be a humidifier inlet 5002 and a humidifier outlet 5004, respectively. The humidifier 5000 can also include a humidifier base 5006, which can be adapted to receive the humidifier reservoir 5110 and include a heating element 5240.

[0400] 5.5.2 Humidifier mechanical parts

[0401] 5.5.2.1 Water storage tank

[0402] According to one arrangement, the humidifier 5000 may include a water reservoir 5110 configured to hold or store a large amount of liquid (e.g., water) to be used for humidification of the air flow. The water reservoir 5110 is configured to hold a predetermined maximum volume of water to provide sufficient humidification for at least the duration of respiratory therapy, such as a night's sleep. Typically, the reservoir 5110 is configured to hold hundreds of milliliters, such as 300 milliliters (ml), 325 ml, 350 ml, or 400 ml of water. In other forms, the humidifier 5000 may be configured to receive a water supply from an external water source, such as a building's water supply.

[0403] According to one aspect, water reservoir 5110 is configured to add humidity to the air flow from RPT device 4000 as the air flow travels through RPT device 4000. In one form, water reservoir 5110 may be configured to encourage air flow to take a tortuous path through reservoir 5110 while contacting a large amount of water therein.

[0404] According to one form, the reservoir 5110 may be detachable from the humidifier 5000, e.g. Figure 5A and Figure 5B In the horizontal direction shown.

[0405] The reservoir 5110 may also be configured to prevent liquid from flowing out thereof, such as through any holes and / or between its subcomponents, such as when the reservoir 5110 is displaced and / or rotated from its normal, working orientation. Since the air flow humidified by the humidifier 5000 is typically pressurized, the reservoir 5110 may also be configured to prevent loss of pneumatic pressure through leaks and / or flow resistance.

[0406] 5.5.2.2 Conduction part

[0407] According to one arrangement, the reservoir 5110 includes a conductive portion 5120 configured to allow efficient transfer of heat from the heating element 5240 to a volume of liquid in the reservoir 5110. In one form, the conductive portion 5120 may be arranged as a plate, although other shapes may also be suitable. All or part of the conductive portion 5120 may be made of a thermally conductive material such as aluminum (e.g., about 2 mm thick, such as 1 mm, 1.5 mm, 2.5 mm, or 3 mm), another thermally conductive metal, or some plastic. In some cases, suitable thermal conductivity may be achieved with a poorly conductive material having a suitable geometry.

[0408] 5.5.2.3 Humidifier reservoir dock

[0409] In one form, the humidifier 5000 may include a humidifier reservoir dock 5130 configured to receive the humidifier reservoir 5110 (e.g., Figure 5B ). In some arrangements, the humidifier reservoir dock 5130 may include a locking feature, such as a locking rod 5135 configured to retain the reservoir 5110 in the reservoir dock 5130.

[0410] 5.5.2.4 Water level indicator

[0411] The humidifier reservoir 5110 may include Figure 5A-5B 5150. In some forms, the water level indicator 5150 can provide a user, such as the patient 1000 or a caregiver, with one or more indications regarding the volumetric 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 volume of water or any portion thereof, such as 25%, 50%, or 75%, or a volume such as 200 ml, 300 ml, or 400 ml.

[0412] 5.5.3 Humidifier electrical and thermal components

[0413] Humidifier 5000 may include a number of electrical and / or thermal components, such as those listed below.

[0414] 5.5.3.1 Humidifier converter(s)

[0415] In place of or in addition to the transducer 4270 described above, the humidifier 5000 may include one or more humidifier transducers (sensors) 5210. The humidifier transducer 5210 may include, for example, Figure 5COne or more of an air pressure sensor 5212, an air flow sensor 5214, a temperature sensor 5216, or a humidity sensor 5218 are shown. The humidifier transducer 5210 may generate one or more output signals that may be transmitted 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 (such as in the air circuit 4170) while transmitting the output signal to the controller.

[0416] 5.5.3.1.1 Pressure transducer

[0417] In addition to or in lieu of the pressure transducer 4272 provided in the RPT device 4000 , one or more pressure transducers 5212 may be provided with the humidifier 5000 .

[0418] 5.5.3.1.2 Flow converter

[0419] In addition to or in lieu of the flow transducer 4274 provided in the RPT device 4000 , one or more flow transducers 5214 may be provided to the humidifier 5000 .

[0420] 5.5.3.1.3 Temperature converter

[0421] 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 air flow downstream of the humidifier outlet 5004. In some forms, the humidifier 5000 may also include a temperature transducer 5216 to detect the temperature of the ambient air.

[0422] 5.5.3.1.4 Humidity Sensor

[0423] In one form, the humidifier 5000 may include one or more humidity sensors 5218 to detect the humidity of a gas such as ambient air. The humidity sensor 5218 may be placed towards the humidifier outlet 5004 in some form to measure the humidity of the gas delivered from the humidifier 5000. The humidity sensor may be an absolute humidity sensor or a relative humidity sensor.

[0424] 5.5.3.2 Heating elements

[0425] In some cases, a heating element 5240 may be provided to the humidifier 5000 to provide heat input to one or more water volumes and / or air flows in the humidifier reservoir 5110. The heating element 5240 may include a heat generating component, such as a resistive heating track. A suitable example of a heating element 5240 is a layered heating element, such as described in PCT Patent Application Publication No. WO2012 / 171072, the entire document of which is hereby incorporated by reference herein.

[0426] In some forms, a heating element 5240 may be provided in the humidifier base 5006, where heat may be provided to the humidifier reservoir 5110 primarily by conduction, such as Figure 5B shown.

[0427] 5.5.3.3 Humidifier controller

[0428] According to one arrangement of the present technology, the humidifier 5000 may include a humidifier controller 5250, such as Figure 5C In one form, the humidifier controller 5250 may be part of the central controller 4230. In another form, the humidifier controller 5250 may be a separate controller that may communicate with the central controller 4230.

[0429] In one form, the humidifier controller 5250 may receive as input, for example, measurements of air flow, properties of the water in the reservoir 5110 and / or the humidifier 5000, such as temperature, humidity, pressure and / or flow rate. The humidifier controller 5250 may also be configured to execute or implement a humidifier algorithm and / or deliver one or more output signals.

[0430] like Figure 5C As shown, 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 .

[0431] 5.6 Respiratory waveform

[0432] Fig. 6A Shows a typical breathing waveform model of a person sleeping. The horizontal axis is time and the vertical axis is respiratory flow. Although the parameter values ​​can vary, a typical breath can have the following approximate values: tidal volume, Vt, 0.5L, inhalation time, Ti, 1.6s, peak inspiratory flow, Q 最高 , 0.4L / s, exhalation time, Te, 2.4s, maximum exhalation flow, Q 最高, -0.5 L / s. The total duration of breathing Ttot is about 4 seconds. A person generally breathes at a rate of about 15 breaths per minute (BPM), and the ventilation Vent is about 7.5 L / min. A typical duty cycle, Ti to Ttot ratio is about 40%.

[0433] Figure 6B A patient is shown during a typical non-REM sleep breathing period of about 90 seconds, with about 34 breaths, being treated with auto-PAP, and with a mask pressure of about 11 cm H2O. The top channel shows blood oxygen saturation (SpO2) with a scale in the vertical direction ranging from 90 to 99% saturation. The patient maintained about 95% saturation throughout the period shown. The second channel shows quantitative respiratory airflow and has a scale in the vertical direction ranging from -1 to +1 LPS with positive inspiration. Chest and abdominal movements are shown in the third and fourth channels.

[0434] Figure 6C A multi-channel sleep record of a patient before treatment is shown. There are 11 signal channels from top to bottom with a 6-minute horizontal span. The top two channels are EEG (electroencephalogram) from different scalp locations. The periodic spikes in the second EEG represent cortical excitation and related activity. The third channel is the submental EMG (electromyogram). The increased activity around the awakening time represents the recruitment of the genioglossus muscle. The fourth & fifth channels are EOG (electrooculogram). The sixth channel is an electrocardiogram. The seventh channel shows pulse oximetry (SpO2), which is repeatedly desaturated from about 90% to less than 70%. The eighth channel is the respiratory airflow using a nasal cannula connected to a differential pressure transducer. 25 to 35 seconds of repetitive apnea alternates with 10 to 15 seconds of bursts of recovery breathing consistent with EEG awakening and increased EMG activity. The ninth channel shows the movement of the chest and the tenth shows the movement of the abdomen. The abdomen shows a crescendo movement within the length of the apnea that causes awakening. Both become chaotic during arousal due to the overall movement during recovery breathing enhancement. Therefore, the apnea is obstructive and severe. The bottom channel is posture, and it shows no change in this example.

[0435] Fig.6D Flow data for a patient who was experiencing a series of total obstructive apneas is shown. The duration of the recording was about 160 seconds. The flow rate ranged from about +1 L / s to about -1.5 L / s. Each apnea lasted about 10-15 seconds.

[0436] 5.7 Heat and Moisture Exchanger (HME)

[0437] 5.7.1 Overview of HME

[0438] Figures 7A to 7DAn embodiment of an HME according to the present technology is shown. Fig. 7A A cross section of an HME 7000 is shown that includes a corrugated structure 7002 that includes a plurality of corrugations 7030 between a substantially flat base top structure 7010 and a substantially flat base base structure 7020 to form an accordion layer 7001. Layer 7001 includes a plurality of upper channels 7012 formed between the upper surface of the corrugated structure 7002 and the top structure 7010. In addition, layer 7001 includes a plurality of lower channels 7022 between the lower surface of the corrugated structure 7002 and the base structure 7020. HME 7000 allows a flow of inhalable gas and a flow of exhaled gas to flow through a plurality of upper 7012 and lower 7022 channels along the surface of the corrugated structure to exchange heat and moisture. Moisture is absorbed by the exhaled gas exhaled from the patient and retained in the material of the corrugated structure 7002. The material of corrugation 7030, top structure 7010 and / or base structure 7020 can comprise paper or paper-based material capable of absorbing water and / or heat. The material of corrugation 7030, top structure 7010 and / or base structure 7020 can be porous, water-permeable and / or breathable. The retained moisture can be delivered to the patient by humidifying the respirable gas stream of the patient's airway subsequently. In other words, the flow of the respirable gas delivered to the patient's airway can absorb the moisture from HME 7000. Figure 7B Various dimensions of the HME are shown according to these embodiments.

[0439] The plurality of corrugations 7030 increase the surface area of ​​the corrugated structure 7002, which increases the effective surface area for heat and moisture exchange between the corrugated structure 7002 and the surrounding volume provided by the plurality of upper 7012 and lower 7022 channels. The top structure 7010 and the base structure 7020 may also be formed of the same heat and moisture exchange material as the corrugated structure 7030. Alternatively, the top structure 7010 and / or the base structure 7020 may be formed of a rigid or semi-rigid material that does not absorb moisture to support the corrugated structure 7002.

[0440] The humidification performance of HME 7000 depends on the effective surface area of ​​HME 7000 provided in a fixed spatial volume. The effective surface area is the surface area of ​​HME 7000 that is exposed to the flow of breathable gas flowing along the surface of the HME where heat and moisture exchange occurs. The surface area per unit volume of HME 7000 can be adjusted by providing corrugations 7030 in the heat and moisture exchange portion of HME 7000. In addition, the surface area per unit volume can also be adjusted by adjusting at least one of the thickness, spacing or height of the fins that have an effect on the surface area per unit volume of HME 7000.

[0441] The HME 7000 may include a plurality of layers 7001 stacked along a vertical axis of the HME 7000, such as Figure 7C As shown. These layers 7001 can be stacked vertically so that the base structure 7020 is stacked on top of the corrugated structure 7002 of the adjacent layer 7001 below. There can also be several layers 7001 of HME stacked in the horizontal direction. Having several layers 7001 including corrugated structures 7002 stacked along the vertical axis of the HME 7000 also increases the surface area per unit volume of the HME. This increased surface area within a predetermined volume increases the heat and moisture exchange efficiency of the HME 7000. In addition, the layers 7001 can be compressed under preload, such as Fig.7D As depicted, increasing the number of layers within a fixed volume increases the surface area per unit volume. By the formula: Calculate preload, where P is the preload and h 开始 is the corrugation or flute height before compression, and where h 最后 is the height of the corrugation after compression.

[0442] Alternatively, the final three-dimensional shape of the HME 7000 may be formed by combining layers 7001 of different sizes and shapes to produce an HME 7000 having an irregular shape suitable for fitting within the plenum chamber 3200 of the patient interface 3000. The layers 7001 may be laser cut to form the desired shape and size.

[0443] like Figures 8A to 8D , showing an alternative embodiment, the HME 7000 can be rolled from a single strip layer 7001, the single strip layer 7001 including a corrugated structure 7002 extending from the surface of the base structure 7020 to form a plurality of corrugations 7030. The single strip layer 7001 can be rolled so that the upper folded portion 7031 of the corrugation 7030 engages the lower surface of the base structure 7020. This configuration ensures that the plurality of channels 7012 are maintained between each roll of the single strip layer 7001. The HME 7000 can be positioned within the plenum chamber 3200 of the patient interface 3000.

[0444] Figures 9A to 9J, showing another embodiment of the present technology. The patient interface 3000 in this embodiment has a removably engaged cushion assembly 3130 including a plurality of cushion assembly engagement members 3135 in the form of a clip including an elastic flange that is removably engaged to a mask frame 3250. The mask frame 3250 includes a mask frame engagement member 3155 in the form of a groove or hole that allows the elastic flange of the cushion assembly engagement member 3235 to pass through and removably engage therewith. Optionally, the cushion assembly 3130 can be engaged to the mask frame by other methods, such as hooks, adhesives, meshing or frictional engagement. The cushion assembly 3130 includes a seal-forming structure 3100. The seal-forming structure 3100 can form a seal with the entrance of the patient's airway. In addition, the seal-forming structure 3100 of the patient interface 3000 can include a pair of nasal sprays or nasal pillows, each of which is constructed and arranged to form a seal with a corresponding nostril of the patient's nose. Optionally, the seal-forming structure may form a seal with the nostrils and the mouth.

[0445] The exemplary patient interface 3000 also includes a detachable HME 7000 that is detachably engaged with the patient interface 3000 and the HME 7000 can be located within the HME housing portion 3420 of the vent adapter 3410. The HME 7000 can include at least one HME engagement member 7004 located on the HME frame 7003. The at least one HME engagement member 7004 can include a clip and each of which can detachably engage a corresponding vent adapter engagement member 3415. The vent adapter 3410 can include a vent 3400 and a mask inlet 3260 located on a front side thereof. The vent adapter 3410 can be adapted to detachably engage to the remainder of the patient interface 3000 and position the detachably engaged HME 7000 within its HME housing portion 3420. The vent adapter 3410 can position the HME 7000 in the flow of breathable gas within the plenum chamber 3200 of the patient interface 3000 and can orient the multiple channels 7012 and 7022 of the HME to be substantially aligned or parallel to the flow of breathable gas, thereby allowing the flow through the HME to pass through the channels 7012 and 7022. Placing the HME 7000 close to the entrance of the patient's airway can maximize the capture and retention of moisture provided to the material of the HME 7000 during exhalation. In addition, the orientation of the channels 7012, 7022 can also allow the humidified gas flow exhaled from the patient to flow back through the channels 7012, 7022 of the HME.

[0446] exist Figures 12A to 12DThe vent adapter 3410 shown in FIG. 34 can position the HME 7000 within the plenum chamber 3200 and can divide the plenum chamber 3200 into a front plenum chamber 3240 and a rear plenum chamber 3230. This placement of the HME 7000 can place the vent 3400 and inlet 3260 on the front side of the HME 7000 as part of the front plenum chamber 3240, while the inlet to the patient's airway is located on the rear side of the HME 7000, adjacent to the rear plenum chamber 3230. This configuration can allow the flow of exhaled gas from the patient to flow into the rear plenum chamber 3240 before being discharged, which allows any moisture to remain in the HME 7000 before being lost from the vent 3400. In addition, this configuration also allows the flow of breathable gas to flow through the HME 7000 before re-delivering the captured moisture to the patient. Thus, the housing portion 3410 may provide a configuration for redelivering humidified air to the patient via the HME 7000 located in the flow path of the patient interface 3000 .

[0447] The vent adapter 3410 may also include a receiving portion 3440 to receive a corresponding engagement member 7004 of the HME frame 7003. The receiving portion 3440 may be releasably snap-fitted to the engagement member 7004. The vent adapter 3410 may also include an attachment member 3450 to releasably connect the vent adapter 3410 to the mask frame 3250. The attachment member 3450 may attach the vent adapter 3410 to the mask frame with a snap fit.

[0448] In addition, auxiliary vents 3401 may also be placed on the rear side of the HME in the rear plenum chamber 3240 to offset the CO2 accumulated in the volume. For example, in the case of a full face mask, the extra volume (i.e., dead space volume) in the rear plenum chamber 3240 may result in undesirable and / or excessive CO2 accumulation in the space compared to a smaller mask. To mitigate this effect, auxiliary vents 3401 may be placed on the rear side or patient side of the HME 7000, close to the patient's airway. Placing auxiliary vents 3401 on the rear side of the HME 7000 will result in some discharge of the humidified breathable gas flow before being delivered to the patient. To compensate for this discharge of humidified air, the overall humidification performance may be maintained by increasing the ability of the HME 7000 to humidify the breathable gas flow in the predetermined volume of the plenum chamber 3400.

[0449] The vent adapter 3410 may also include a baffle 3430 to separate the incoming breathable gas flow and the CO2 flushing flow. The baffle 3430 may separate these gas flows from each other so that the gas flows do not interfere with each other. U.S. Patent No. 7,934,501, which is incorporated herein by reference in its entirety, describes further embodiments and features of baffles that may be suitable for use with the exemplary patient interface 3000.

[0450] Figures 10 to 10F depict an embodiment of an HME frame 7003 according to the present technology. The HME frame 7003 may include one or more engagement members 7004. The engagement member 7004 may be releasably engaged with the vent adapter 3410. Optionally, the engagement member 7004 may also allow the HME frame 7003 to directly and 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 holes 7006 to allow the inhalable gas flow and / or the exhaled gas flow to flow through the frame holes 7006 and through the HME layer 7001. The HME frame 7003 may also include one or more HME retaining members 7005. The HME retaining member 7005 can hold the HME layer 7001 in place and the HME retaining member 7005 can also provide structural support for the HME frame 7003. The HME retaining member 7005 can be provided to the front and / or rear of the HME frame 7003. Respectively at Fig. 10A and 10B , the HME frame 7003 has a generally rectangular shape. It should be understood that the HME frame 7003 has other shapes and provides 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. Accordingly, the HME layer 7001 may be shaped to conform to the internal shape of the HME frame 7003 depending on the shape of the HME frame 7003. Fig. 10D A top view of the HME frame 7003 is shown and in this view it can be seen that the HME frame 7003 according to this embodiment of the present technology is swept back at its lateral ends to illustrate the shape of the patient interface 3000. It should be understood that the HME frame 7003 may also have a profile that is also flat or swept forward from this view, depending on the shape of the patient interface 3000.

[0451] As in Figures 11A to 11G7000 can be stacked in layer 7001 and further include rigid support HME frame 7003. HME layer 7001 can be retained in HME frame 7003 by one or more HME retaining members 7005. HME frame 7003 can include frame holes 7006 aligned with multiple channels 7012 and 7022 defined by corrugation 7030 and run through layer 7001 of HME 7000. Frame holes 7006 allow gas flow to flow through HME in two directions, which allows heat and moisture exchange to be retained and re-delivered to the patient. The predetermined three-dimensional shape of the inward curvature of the HME frame 7003 is suitable for fitting into the plenum chamber 3200 of the patient interface 3000 and avoiding contact with the patient's face when the patient interface 3000 is placed on the face. Other predetermined three-dimensional shapes can be provided to avoid contact with the patient's face while keeping the ability of HME 7000 fitting in the plenum chamber 3200 of the patient interface 3000.

[0452] Fig.13A A flow chart of an exemplary method that may be followed to select an appropriate heat and moisture exchanger (HME or HMX) is shown. The exemplary method may be used to test whether an HME is able to achieve desired parameters associated with humidification performance. This method is adapted from ISO 9360. The method includes simulating a humidified lung and placing the lung in fluid communication with a patient interface under various test conditions. The test conditions may include:

[0453] i) No humidification

[0454] ii) Passive humidification using HME in the mask. Use a corrugated HME comprising multiple layers including Fig. 13C The corrugated structure of the F-groove shown in FIG. Fig.13D Properties listed under 'Tested HME (Flute F)'.

[0455] iii) Active humidification using active humidifier H5i at 23°C, RH80%

[0456] iv) Active humidification using active humidifier H5i at 30°C, RH80%

[0457] As in Fig. 13B As shown in the exemplary results shown in , the humidified lung weight loss is used as an indicator of humidity loss in the lungs of a patient under simulated RPT therapy. As expected, non-humidified i) showed the highest weight loss, simulating humidity loss through a patient under RPT therapy without any additional humidification. This may ultimately lead to respiratory discomfort. Passive humidification performed better than active humidification via H5i at 23°C, RH80%. Passive humidification also performed close to extreme humidification at 30°C, RH80% using an active humidifier H5i. The tests were conducted under environmental conditions of 15.5°C, RH30%. According to Fig.13D The properties listed under 'Tested HME (Flute F)' are listed for the HME tested with a 5.4 m 2 / m 3 The surface area per unit volume.

[0458] Fig. 13C Various corrugation or flute configurations are shown for forming a corrugated structure included in a non-preloaded HME. F-flutes can be used to form a corrugated structure including multiple corrugated layers of HME. In a non-preloaded and assembled configuration, the corrugated structure can be formed from corrugated paper with a height of 0.9 mm and a paper grade of 65 gsm.

[0459] Fig.13D Parameters of various corrugated structures according to embodiments of the present technology are shown. A "tested HME" comprising multiple layers in a fluted F configuration is under a 6% preload. This configuration provides the HME with a 8360 mm 3 The total volume and 5.42m 2 / m 3 The total surface area per unit volume was found to be 0.47 cm of water column. The HME under optimal conditions may include 26 layers stacked at 32% preload, resulting in 4560 mm 3 The total volume and 7.5m 2 / m 3 The HME has a flow impedance of 1.6 cm of water column, which can provide a smaller HME with improved humidification performance within an acceptable impedance range. Fig.13E The measured dimensions are shown to provide Fig.13D The corrugation circumference is the length of the paper material that forms a single corrugation or groove. Fig.13D As listed, this length remains between the tested HME and the optimal HME as the preload is increased to compress the corrugations to a smaller volume. A compressive force under preload is applied to the folded portion of the corrugations to reduce the flute height while maintaining the flute spacing. Stacking refers to multiple layers stacked vertically into the three-dimensional shape shown, wherein, as the preload increases, the stack height decreases, thereby increasing the surface area per unit volume of the HME.

[0460] The embodiment of the technology is directed to the HME 7000 located within the functional dead space of various full-face patient interfaces 3000 (see FIG. 14A to FIG. 14F , Fig.15A To Figure 15 and Fig.16). The HME 7000 can be positioned in 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 can be supported and held in place by a support film 7050, which can be connected to the inner wall of the plenum chamber 3200. The form of the HME 7000 in these embodiments is circular and has a thickness of about 5-10 mm. Optionally, the HME material can be formed into a contour shape that is directly assembled to the inner contour of the plenum chamber 3200, wherein the HME can present a shape complementary to the interior of the plenum chamber 3200. In this case, the shape can be a three-dimensional surface with a thickness of about 1-10 mm.

[0461] In one embodiment of a non-invasive patient interface 3000 according to one aspect of the present technology, the patient interface 3000 may include the following functional aspects: a seal-forming structure 3100, a plenum chamber 3200, an HME 6000 located in a functional dead space within the plenum chamber 3200, a support membrane 7050 configured to hold the HME 7000 in place, a positioning and stabilizing 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, one physical component may provide one or more functional aspects. In use, the seal-forming structure 3100 is arranged to surround the entrance to the patient's airway so as to facilitate air to be supplied to the airway at a positive pressure.

[0462] A positioning and stabilizing structure 3300 may also be provided to releasably secure the patient interface 3000 to the patient 1000. The positioning and stabilizing structure 3300 may include a plurality of straps that are adjustable in length to allow the patient interface to be comfortably and securely mounted to the patient 1000 such that a pneumatic seal is formed around the patient's airway by the seal-forming structure 3100. A strap connector 3301 may also be provided to releasably secure the straps of the positioning and stabilizing structure 3300 to the patient interface 3000. The straps of the positioning and stabilizing structure 3300 may include hook and loop material for length adjustment and to allow the straps of the positioning and stabilizing structure 3300 to be connected to and separated from the strap connector 3301. It should be understood that the strap connector 3301 may be releasably attached to the patient interface 3000 or it may be integrally formed therewith.

[0463] The positioning of HME 7000 in the patient interface can be changed to adjust the hygroscopic performance. For example, the distance between the airway of HME and patient 1000 can be adjusted. In addition, the distance between HME 7000 and vent 3400 and / or inlet 3260 can also be adjusted. The positioning of regulating HME 7000 can change the hygroscopic performance of HME by adjusting the position of HME 7000 relative to the airway of patient 1000. That is, the closer HME 7000 is to the airway of patient 1000, the closer it is to the humidity source during exhalation and the closer it is to the target of humidification during inhalation. However, HME 7000 can be positioned so that it avoids contacting with the patient's face. Similarly, the position of regulating HME 7000 may also affect the impedance to flow due to the positioning relative to inlet 3260, and affect the effect of CO2 washout affected by the relative position of vent 3400. By positioning the HME 7000 in the functional dead space of the patient interface 3000, the HME may occupy a larger volume than the volume that the HME 7000 will occupy in the air delivery conduit or elbow. This in turn can allow greater flexibility to position the HME 7000 in a larger volume to minimize the impedance and CO2 washout to the treatment flow, while allowing maximization of hygroscopic performance. Although all of the above benefits also apply to molded HME inserts, the HME insert concept can provide greater design control and can reduce the compromise between conflicting functions. Similarly, the thickness and area of ​​the HME 7000 can also be changed to adjust these characteristics. For example, an HME 7000 with an increased surface area can have increased hygroscopic performance. In addition, a thinner HME 7000 can increase its permeability and therefore reduce impedance.

[0464] In these embodiments, the flexible support membrane 7050 can be positioned to connect within the inner wall of the plenum chamber 3200 and support the HME 7000 within the functional dead space of the patient interface 3000. The flexible support membrane 7050 can be made of a flexible material such as silicone but can also be made from an HME material. This flexibility allows for easy manipulation and movement of the flexible support membrane 7050 holding the HME 7000. In addition, the flexible support membrane 7050 can be impermeable to the humidified air exhaled from the airway of the patient 1000 to avoid any humidification loss through the vent 3400. The impermeability of the flexible support membrane 7050 can ensure that the exhaled humidified air passes through the HME 7000 in order to maximize the hygroscopic performance.

[0465] In another embodiment, the HME 7000 may be positioned in the functional dead space within the plenum chamber 3200 of the patient interface 3000 , in the form of a nasal mask supported by the support membrane 7050 .

[0466] In one embodiment of the present technology, the Humiflo HME is used to measure the increased humidity above the ambient humidity, such as Fig.17 As shown, it has a diameter of 35 cm and a volume of 10 cm 3 The HME was positioned in the functional dead space of the ResMed Quattro FX patient interface. Of note, leaks at the patient interface can result in an increase in the mean value of the flow rate through the plenum chamber of the patient interface, ultimately having a negative impact by reducing the humidity within the patient interface due to losses through the system. Increased humidity was measured over a therapeutic pressure range of 4 cm of H2O to 20 cm of H2O (over a flow rate range of 20 L / min to 50 L / min). Fig.17 The increased absolute humidity of about 5 mg / L to 18 mg / L is shown. More specifically, the graph shows an increased absolute humidity of 9.5 mg / L to 17.5 mg / L at the same flow rate. The humidity over time at a specific pressure is within the range of the minimum humidity occurring during inspiration and the maximum humidity during exhalation. The average humidity measured over the entire breathing cycle is used as a comparative measure.

[0467] 5.8 Terminology

[0468] In certain forms of the present technology, one or more of the following definitions may apply for purposes of disclosure of the present technology. In other forms of the present technology, alternative definitions may apply.

[0469] 5.8.1 Conventional

[0470] Air: In some forms of the present technology, air may be understood as atmospheric air, while in other forms of the present technology, air may be understood as some other combination of breathable gases, such as an oxygen-enriched atmospheric air.

[0471] Environment: In certain forms of the present technology, the term environment may be understood as (i) external to the treatment system or patient and (ii) directly surrounding the treatment system or patient.

[0472] For example, regarding the environment of the humidifier humidity It may be the humidity of the air directly surrounding the humidifier, such as the humidity of the room the patient is sleeping in. Such ambient humidity may be different from the humidity outside the room the patient is sleeping in.

[0473] In another embodiment, the environment pressure This can be pressure directly around the body or outside the body.

[0474] In some forms, the environment (e.g., acoustic) noiseIt can be considered as the background noise level in the room where the patient is located, in addition to the noise generated by the RPT device or originating from the mask or patient interface, for example. Ambient noise can be generated by sources outside the room.

[0475] Continuous Positive Airway Pressure (CPAP): CPAP therapy refers to the application of an air supply to the airway entrance at a pressure that is continuously positive relative to atmosphere and approximately constant during the patient's breathing cycle. In some forms, the pressure at the airway entrance will be slightly higher during exhalation and slightly lower during inspiration. In some forms, this pressure will vary between different breathing cycles of the patient, for example increasing in response to detection of an indication of partial upper airway obstruction and decreasing in the absence of an indication of partial upper airway obstruction.

[0476] 5.8.2 Exhalation cycle

[0477] Apnea: Apnea is considered to have occurred when the flow drops below a predetermined threshold for a period of time, such as 10 seconds. Obstructive apnea is considered to have occurred when some obstruction of the airway does not allow air to flow despite the patient's efforts. Central apnea is considered to have occurred when an apnea is detected due to reduced breathing effort or absent breathing effort, despite an open airway. Mixed apnea occurs when a reduction or absence of breathing effort occurs simultaneously with airway obstruction.

[0478] Respiratory rate: The rate at which a patient breathes spontaneously, usually measured in breaths per minute.

[0479] Duty cycle: the ratio of inspiratory time Ti to total breathing time Ttot.

[0480] Effort (Breathing): Breathing effort is considered to be the work performed by a spontaneously breathing person attempting to breathe.

[0481] Expiratory portion of the respiratory cycle: the period from the start of expiratory flow to the start of inspiratory flow.

[0482] Flow Limitation: Flow limitation will be considered a state of patient breathing in which an increase in patient effort does not produce a corresponding increase in flow. When flow limitation occurs during the inspiratory portion of the respiratory cycle, it may be described as inspiratory flow limitation. When flow limitation occurs during the expiratory portion of the respiratory cycle, it may be described as expiratory flow limitation.

[0483] Types of flow-limited inspiratory waveforms:

[0484] (i) Flattened: Having a rise followed by a relatively flat portion and then a fall.

[0485] (ii) M-shape: having two local peaks, one at the leading edge and one at the trailing edge, and a relatively flat portion between the two peaks.

[0486] (iii) Chair shape: has a single local peak at the leading edge followed by a relatively flat section.

[0487] (iv) Reverse chair shape: has a relatively flat portion followed by a single local peak at the trailing edge.

[0488] Hypopnea: Hypopnea will be considered a decrease in flow, not an interruption in flow. In one form, when flow drops below a threshold for a period of time, then hypopnea may be considered to have occurred. Central hypopnea may be considered to have occurred when hypopnea is detected due to a decrease in respiratory effort. In one form in adults, any of the following may be considered hypopnea:

[0489] (i) The patient experiences a 30% decrease in respiration for at least 10 seconds with an associated 4% desaturation; or

[0490] (ii) The patient's breathing is reduced (but less than 50%) for at least 10 seconds, with associated desaturations or arousals of at least 3%.

[0491] Hyperpnea: The flow rate rises to a level higher than the normal flow rate.

[0492] Inspiratory portion of the respiratory cycle: The period from the start of inspiratory flow to the start of expiratory flow will be considered the inspiratory portion of the respiratory cycle.

[0493]

[00136] Patency (airway): The degree of airway openness or the extent to which the airway is open. An open airway is open. Airway patency may be quantified, for example with a value of one (1) being open and a value of zero (0) being closed (obstructed).

[0494] Positive End Expiratory Pressure (PEEP): The pressure above atmospheric pressure that exists in the lungs at the end of exhalation.

[0495] Maximum flow (Qpeak): The maximum value of flow during the inspiratory portion of the respiratory flow waveform.

[0496] Respiratory flow, airflow, patient airflow, respiratory airflow (Qr): These synonymous terms can be understood as estimates of the respiratory airflow of the RPT device, as opposed to "true respiratory flow" or "true respiratory airflow", which is the actual respiratory flow experienced by the patient, typically expressed in liters per minute.

[0497] Tidal volume (Vt): The volume of air inhaled or exhaled during normal breathing when no extra effort is exerted.

[0498] (Inspiratory) Time (Ti): Duration of the inspiratory portion of the respiratory flow waveform.

[0499] (Expiratory) Time (Te): Duration of the expiratory portion of the respiratory flow waveform.

[0500] (Total) Time (Ttot): The total duration between the start of the inspiratory portion in one respiratory flow waveform and the start of the inspiratory portion of the next respiratory flow waveform.

[0501] Typical Recent Ventilation: A ventilation value around which recent values ​​within some predetermined timescale tend to cluster, ie, a measure of the central tendency of recent ventilation values.

[0502] Upper airway obstruction (UAO): includes partial and total upper airway obstruction. This may be associated with a state of flow limitation, where the level of flow increases only slightly or even decreases as the pressure difference across the upper airway increases (Starling resistor behavior).

[0503] Ventilation (Vent): A measure of the total amount of gas exchanged through a patient's respiratory system, including both inspiratory and expiratory flow per unit time. When expressed as volume per minute, this quantity is often referred to as "minute ventilation". Sometimes minute ventilation is simply given as volume, which can be understood as volume per minute.

[0504] 5.8.3RPT device parameters

[0505] Flow rate (or flow): The instantaneous volume (or mass) of air delivered per unit time. Although flow rate has the same magnitude of volume or mass per unit time as ventilation, flow rate is measured over a shorter time period. In some cases, reference to flow rate will be reference to a scalar quantity, i.e., a quantity having only magnitude. In other cases, reference to flow rate will be reference to a vector quantity, i.e., a quantity having both magnitude and direction. When referred to as a signed quantity, the flow rate may nominally be positive for the inspiratory portion of the patient's breathing cycle and therefore negative for the expiratory portion of the patient's breathing cycle. The flow rate will be given the sign Q. The total flow Qt is the flow rate of air leaving the RPT device. The ventilation flow Qv is the flow rate of air leaving the vent to allow for the washout of exhaled gases. The leakage flow Ql is the flow rate of unintentional leakage from the patient interface system. The respiratory flow Qr is the flow rate of air received into the patient's respiratory system.

[0506] Leakage: The term leakage will be considered as air flow to the surrounding environment. Leakage can be intentional, for example, to allow flushing of exhaled CO2. Leakage can be unintentional, for example, due to an incomplete seal between the mask and the patient's face. In one embodiment, the leak may occur in the swivel elbow.

[0507] Noise, conducted (acoustic): Conducted noise in this document refers to the noise delivered to the patient by the pneumatic pathways such as the air circuit and patient interface and the air therein. In one form, conducted noise can be quantified by measuring the sound pressure level at the end of the air circuit.

[0508] Noise, radiated (acoustic): Radiated noise in this document refers to the noise that is delivered to the patient by the ambient air. In one form, radiated noise can be quantified according to ISO 3744 by measuring the sound power / pressure level of the subject in question.

[0509] Noise, Ventilation (Acoustic): Ventilation noise in this document refers to the noise generated by the flow of air through any vent, such as the vent in a patient interface.

[0510] Pressure: force per unit area. Can be expressed in cm of water column, gf / cm 2 The pressure is measured in the unit range of 10000 Pascals and 1 cm of water column. 1 cm of water column is equal to 1 g-f / cm2 and is close to 0.98 hectopascals. In this specification, unless otherwise stated, the pressure is given in cm of water column. The pressure in the patient interface is given the symbol Pm. The treatment pressure, which represents the target value to be achieved by the mask pressure Pm at the current instant in time, is given the symbol Pt.

[0511] Sound power: The energy per unit time carried by a sound wave. Sound power is proportional to the sound pressure multiplied by the square of the area of ​​the wave front. It is usually expressed in decibels SWL, which is relative to a sound wave, usually at 10 -12 The sound power is given in decibels relative to the reference power obtained in watts.

[0512] Sound Pressure: The local deviation from ambient pressure at a given moment due to the propagation of sound waves through a medium. Usually expressed in decibels (SPL), which is relative to 20x10 of what is usually considered the threshold of human hearing. -6 The sound pressure is given in decibels relative to a reference pressure taken in Pascals (Pa).

[0513] 5.8.4 Terminology used for ventilators

[0514] Adaptive servo ventilator: A ventilator with a variable rather than fixed target ventilation. The variable target ventilation may be learned from some characteristic of the patient, such as the patient's breathing characteristics.

[0515] Backup rate: A ventilator parameter that establishes the minimum rate of breaths (usually measured in breaths per minute) that the ventilator will deliver to the patient if not otherwise triggered.

[0516] Cyclic: The termination of the inspiratory phase of a ventilator. When a ventilator is delivering breaths to a spontaneously breathing patient, the ventilator is considered to have cycled to stop delivering breaths at the end of the inspiratory portion of the respiratory cycle.

[0517] EPAP (or EEP): The base pressure to which the intra-breath varying pressure is added to produce the desired mask pressure that the ventilator attempts to achieve at a given time.

[0518] IPAP: The desired mask pressure that the ventilator will attempt to achieve during the inspiratory portion of a breath.

[0519] Pressure Support: A number that indicates the increase in pressure during ventilator inspiration relative to the pressure during ventilator exhalation, and usually means the difference in pressure between the maximum during inspiration and the minimum during exhalation (e.g., PS = IPAP - EPAP). In some contexts, pressure support represents the difference that the ventilator intends to achieve, rather than the difference it actually achieves.

[0520] Servo ventilator: A ventilator that measures the patient's ventilation and has a target ventilation, and which adjusts the level of pressure support to cause the patient's ventilation to move toward the target ventilation.

[0521] Spontaneous / Timed (S / T) - A mode of a ventilator or other device that attempts to detect the initiation of a breath in a spontaneously breathing patient. However, if the device is unable to detect a breath within a predetermined period of time, the device will automatically initiate the delivery of a breath.

[0522] Swing: A synonym for Pressure Support.

[0523] Triggering: When a ventilator delivers a breath of air to a spontaneously breathing patient, it is considered to be triggered to do so by the patient's effort at the beginning of the breathing portion of the respiratory cycle.

[0524] Ventilator: A mechanical device that provides pressure support to a patient to perform some or all of the work of breathing.

[0525] 5.8.5 Facial anatomy

[0526] Ala: the outer wall or "wing" of each nostril (plural: alar)

[0527] Alar tip: The most lateral point on the wing of the nose.

[0528] Alanal curvature (or ala summit) point: The most posterior point in the base line of the curvature of each ala, visible in the groove wrinkle formed by the junction of the cheek and the ala.

[0529] Auricle: The entire external visible part of the ear.

[0530] (Nose) Bony framework: The bony framework of the nose includes the nasal bones, the frontal process of the maxilla, and the nasal part of the frontal bone.

[0531] (Nose) Cartilage framework: The cartilage framework of the nose includes the septum cartilage, lateral cartilage, major cartilage and minor cartilage.

[0532] Columella: The strip of skin that separates the nostrils and extends from the prona to the upper lip.

[0533] Columellar angle: The angle between a line drawn through the midpoint of the nostril aperture and a line drawn perpendicular to the Frankfort horizontal and intersecting the subnasal point.

[0534] Frankfurt horizontal plane: A line extending from the lowest point of the orbital rim to the left tragus point. The tragus point is the deepest point in the notch on the tragus of the auricle.

[0535] Glabella: Located on the soft tissue, the most prominent point in the mid-sagittal plane of the forehead.

[0536] Lateral nasal cartilage: A roughly triangular plate of cartilage. Its superior margin is attached to the nasal bones and the frontal process of the maxilla, and its inferior margin is connected to the larger alar cartilage.

[0537] Alar cartilage: A cartilaginous plate located below the lateral nasal cartilages. It curves around the front part of the nostril. Its posterior end is connected to the frontal process of the maxilla by a tough fibrous membrane consisting of three or four small cartilages of the ala.

[0538] Nostril (nose opening): An approximately oval opening that forms the entrance to the nasal cavity. The singular form of nares is naris (nose opening). The nostrils are separated by a nasal septum.

[0539] Nasolabial Folds or Nasolabial Creases: Folds or grooves of skin that extend from each side of the nose to the corners of the mouth, separating the cheeks from the upper lip.

[0540] Nasolabial angle: The angle between the columella and the upper lip, intersecting the subnasal point.

[0541] Auricular base: The lower attachment point of the auricle to the skin of the face.

[0542] Supraauricular base: The upper attachment point of the auricle to the skin of the face.

[0543] Nasal prominence: The most prominent point or tip of the nose, which can be identified in a side view of the rest of the head.

[0544] Philtrum: The midline groove extending from the lower border of the nasal septum to the top of the lip in the upper lip area.

[0545] Premental point: located on the soft tissue at the front-most middle point of the chin.

[0546] Bridge: The bridge of the nose is the midline protrusion of the nose extending from the nasion to the protuberance.

[0547] Sagittal plane: A vertical plane that passes from the front (front end) to the back (back end), dividing the body into right and left halves.

[0548] Nasion: Located on the soft tissue, the most concave point of the area covering the frontonasal suture.

[0549] Septal Cartilage (Nose): The septal cartilage forms part of the nasal septum and divides the front of the nasal cavity.

[0550] Posterior superior lateral flap: The point at the inferior edge of the alar base where the alar base joins the skin of the superior (upper) lip.

[0551] Subnasal point: located on the soft tissue at the point where the columella joins the upper lip in the mid-sagittal plane.

[0552] Chin point: The point of greatest concavity in the midline of the lower lip between the midpoint of the lower lip and the premental point of the soft tissue.

[0553] 5.8.6 Anatomy of the skull

[0554] Frontal Bone: The frontal bone consists of a large vertical portion, the squama, corresponding to the area called the forehead.

[0555] Mandible: The mandible forms the lower jaw. The mental protuberance is the bony protrusion of the jaw that forms the chin.

[0556] Maxilla: The maxilla forms the upper jaw and is located above the mandible and below the eye sockets. The frontal process of the maxilla projects upward on the side of the nose and forms part of its lateral border.

[0557] Nasal bones: The nasal bones are two small oval bones that vary in size and shape in different individuals; they are arranged side by side in the middle and upper part of the face and, through their union, form the "bridge" of the nose.

[0558] Nasion: The intersection of the frontal bone and the two nasal bones, the concave area just between the eyes and on the bridge of the nose.

[0559] Occipital Bone: The occipital bone is located at the back and bottom of the skull. It contains the oval hole, the foramen magnum, through which the cranial cavity communicates with the vertebral canal. The curved plate behind the foramen magnum is the squamata.

[0560] Socket: The bony cavity in the skull that holds the eyeball.

[0561] Parietal bones: The parietal bones are the bones that, when joined together, form the top and sides of the skull.

[0562] Temporal bones: The temporal bones are located at the base and sides of the skull and support the part of the face called the temple.

[0563] Zygomatic bones: The face includes two zygomatic bones located in the upper and sides of the face and forming the prominence of the cheeks.

[0564] 5.8.7 Anatomy of the respiratory system

[0565] Diaphragm: A sheet of muscle that stretches across the bottom of the chest cavity. The diaphragm separates the chest cavity, which contains the heart, lungs, and ribs, from the abdominal cavity. When the diaphragm contracts, the volume of the chest cavity increases and air is drawn into the lungs.

[0566] Larynx: The larynx or larynx houses the vocal cords and connects the lower part of the pharynx (hypopharynx) to the trachea.

[0567] Lung: The respiratory organ in the human body. The conducting area of ​​the lungs includes the trachea, bronchi, bronchioles, and terminal bronchioles. The respiratory area includes the respiratory bronchioles, alveolar tubules, and alveoli.

[0568] Nasal Cavity: The nasal cavity (or nasal fossa) is a large air-filled space above and behind the nose in the middle of the face. The nasal cavity is divided in two by a vertical fin called the nasal septum. On either side of the nasal cavity are three horizontal outgrowths called turbinates (conchae, in the singular) or nasal conchae. In front of the nasal cavity is the nose, and in the back of the nasal cavity it merges into the nasopharynx via the posterior nares.

[0569] Pharynx: The portion of the throat located just below (under) the nasal cavity and above the esophagus and larynx. The pharynx is usually divided into three parts: the nasopharynx (epipharnyx) (nasal portion of the pharynx), the oropharynx (mesopharynx) (oral portion of the pharynx), and the hypopharynx (hypopharnyx).

[0570] 5.8.8 Materials

[0571] Silicone or Silicone Elastomer: A 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 manufactured by Dow Corning (including a range of products sold under that trademark). Another manufacturer of LSR is Wacker. Unless otherwise specified to the contrary, forms of LSR have a Shore A (or Type A) indentation hardness ranging from about 35 to about 45 as measured using ASTM D2240.

[0572] Polycarbonate: A usually transparent thermoplastic polymer of bisphenol A carbonate.

[0573] 5.8.9 Patient Interface

[0574] Anti-Asphyxia Valve (AAV): A component or sub-assembly of a mask system that reduces the risk of the patient rebreathing excess carbon dioxide by opening to the atmosphere in a fail-safe manner.

[0575] Bend: A conduit that directs the axis of the airflow at an angle to change direction. In one form, the angle may be approximately 90 degrees. In another form, the angle may be less than 90 degrees. The conduit may have an approximately circular cross-section. In another form, the conduit may have an elliptical or rectangular cross-section.

[0576] Mask frame: A mask frame refers to a mask structure used to bear the tensile load between two or more connection points with the headgear. A mask frame can be a non-airtight load-bearing structure in a mask. However, some forms of mask frames can also be airtight.

[0577] Headband: Headband refers to a type of positioning and stabilizing structure designed to be worn on the head. The headband may include a collection of one or more struts, straps, and stiffeners configured to place and hold the patient interface in place on the patient's face for delivery of respiratory therapy. Some straps are formed of a laminate composite of soft, flexible, resilient materials such as foam and fabric.

[0578] Membrane: A membrane refers to a generally thin element that has no significant resistance to bending but has resistance to stretching.

[0579] Plenum: A mask plenum means a portion of a patient interface having walls enclosing a volume of space which, in use, has air therein pressurized above atmospheric pressure. The housing may form part of the walls of the mask plenum.

[0580] Seal: The noun form ("seal") refers to a structure or barrier that intentionally resists airflow across the interface of two surfaces. The verb form ("to make a seal") refers to resisting airflow.

[0581] Shell: Shell refers to a curved two-dimensional structure with a curved, elongated and compressible stiffness, such as a portion of a mask used to form the curved structural walls of the mask. It is thinner than the overall dimensions. In some forms, the shell is faceted. The walls may be airtight, but in some forms they may not be airtight.

[0582] Reinforcement: Reinforcement means a structural component designed to increase the bending resistance of another component in at least one direction.

[0583] Strut: A strut is a structural component designed to increase the compressive resistance of another component in at least one direction.

[0584] Swivel: (noun) A subassembly of an assembly configured to rotate independently and under low torque about a common axis. In one form, the swivel may be configured to rotate through an angle of at least 360 degrees. In another form, the swivel may be configured to rotate through an angle of less than 360 degrees. When used in the context of an air delivery conduit, this subassembly of the assembly includes a matched pair of cylindrical conduits. There is preferably little or no airflow leakage from the swivel in use.

[0585] Ties: Ties are structural components designed to resist tension.

[0586] a vent: (noun) A structure that allows the intentional flow of air from the interior of a mask or tube to the ambient air, e.g., to allow washout of exhaled breath.

[0587] 5.8.10 Terms related to patient interface

[0588] Curvature (of a surface): A surface with a saddle-shaped area that curves in one direction and curves down in a different direction is said to have negative curvature. A surface with a dome-shaped area that curves in the same way in two principal directions will be said to have positive curvature. A flat surface will be considered to have zero curvature.

[0589] Having one or more of the following properties of a material, structure, or composition:

[0590] a) Easily adaptable to acupressure.

[0591] b) is unable to maintain its shape when caused to support its own weight.

[0592] c) non-rigid.

[0593] d) easily stretch or bend elastically.

[0594] A floppy property may have an associated direction, so a particular material, structure, or composite may be floppy in a first direction but stiff or rigid in a second direction, such as a second direction orthogonal to the first direction.

[0595] Resilient: Capable of deforming elastically significantly within a relatively short period of time, such as 1 second, and releasing substantially all of the energy after unloading.

[0596] Rigid: Not easily deformed by finger pressure and / or tensions or loads normally encountered when establishing and maintaining a sealing relationship between the patient interface and the entrance to the patient's airway.

[0597] Semi-rigid: means sufficiently rigid to not deform significantly under the mechanical forces typically applied during positive airway pressure therapy.

[0598] 5.9 Other notes

[0599] A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyrights whatsoever.

[0600] Unless the context clearly indicates otherwise or a range of values ​​is provided, it is understood that each intervening value to the tenth of the unit of the lower limit between the upper and lower limits of the range and any other stated or intermediate values ​​in the described range are included in the present technology. The upper and lower limits of these intermediate values ​​that can be independently included in the intermediate ranges are included in the present technology, unless there are any specifically excluded limitations in the described ranges. In the case where the described range includes one or two limitations, ranges not including one or two of these limitations are also included in the present technology.

[0601] Furthermore, where values ​​are expressed herein as being implemented as part of the present technology, it is to be understood that the values ​​may be approximate unless otherwise indicated and that the values ​​may be used with any suitable significant figures as permitted or required for the particular technology application.

[0602] All technical and scientific terms described herein have the same meaning as commonly understood by one of ordinary skill in the art to which the technology belongs, unless otherwise stated. Although any methods and materials identical or equivalent to those described can also be used in the practice and testing of the present technology, a limited number of exemplary methods and materials are described herein.

[0603] When specific materials are considered to be used to configure a component, obvious alternative materials with similar properties may be used as substitutes. In addition, any and all components described herein are understood to be capable of being configured or manufactured separately or configured or manufactured together, unless specifically stated otherwise.

[0604] It must be noted that as used herein and in the claims, the singular forms "a," "an," and "the" include their plural equivalents unless the context clearly dictates otherwise.

[0605] All disclosures described herein are incorporated herein by reference, and they describe methods and / or materials of those disclosed themes. Disclosures described herein are provided to be used only for disclosures before the filing date of the present application. Anything herein should not be interpreted as allowing the present technology to not have qualifications earlier than the disclosure. In addition, the disclosed date provided may be different from the actual publication date, wherein, it may be necessary to independently confirm the actual publication date.

[0606] The terms “include” and “comprising” should be interpreted as referring to elements, components or steps in a non-exhaustive manner, indicating that the elements, components or steps referred to may be present or utilized or combined with other elements, components or steps not explicitly referred to.

[0607] The subject headings used in the detailed description are included for the reader's convenience and should not be used to limit the subject matter found throughout the disclosure or claims. The subject headings should not be used to interpret the scope of the claims or the limitations of the claims.

[0608] Although the technology of this article is described with reference to specific embodiments, it is to be understood that these embodiments are only used to illustrate the principles and applications of the technology. In some cases, terms and symbols may imply specific details that are not required for implementing the technology. For example, although the terms "first" and "second" may be used, they are not intended to indicate an arbitrary order but to distinguish between different elements unless otherwise specified. In addition, although the process steps of the method can be described or illustrated in order, the order is not necessary. Those skilled in the art will recognize that the order can be modified and / or its scheme can be performed simultaneously or even synchronously.

[0609] It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the technology.

Claims

1. A patient interface for delivering a flow of breathable gas to an airway entrance of a patient including at least a nares entrance of the patient, the patient interface comprising: plenum chamber; a heat and moisture exchanger (HME) located in the plenum chamber to divide the plenum chamber of the patient interface into a first anterior chamber and a second posterior chamber, the HME being configured to humidify a flow of breathable gas from the first anterior chamber to the second posterior chamber, wherein the HME is adapted to releasably engage a patient interface; wherein a seal-forming structure is provided for the patient interface to seal against a portion of the patient's face, the seal-forming structure being adjacent to the second posterior chamber; as well as The first antechamber includes an inlet for receiving a flow of breathable gas into the first antechamber and a vent for flushing an exhaled gas flow from the first antechamber, wherein the inlet and the vent are located on the first antechamber in front relative to the HME.

2. A patient interface according to claim 1, wherein the vent is configured to regulate the flushing of exhaled gas at a substantially constant flow rate.

3. The patient interface of claim 2, wherein the patient interface further comprises: a vent adapter including a vent and an inlet; as well as A gasket assembly including an opening and a seal forming structure; The vent adapter is adapted to be removably coupled to the cushion assembly to form a plenum chamber.

4. A patient interface according to claim 3, wherein a front portion of the vent adapter forms at least one wall of the first anterior chamber.

5. A patient interface according to claim 4, wherein the vent adapter includes walls forming a housing portion for receiving the HME.

6. A patient interface according to claim 5, wherein the housing portion is configured to position the HME within the plenum chamber.

7. A method of manufacturing a patient interface for delivering a flow of breathable gas to an entrance of an airway of a patient, the patient interface comprising a heat and moisture exchanger (HME) having desired humidification performance for humidifying the flow of breathable gas, the method comprising: manufacturing patient interfaces; determining a volume of a plenum chamber of a patient interface for delivering a flow of breathable gas to a patient; corrugating at least a portion of the HME to form a plurality of channels to allow a flow of breathable gas through the HME and along a surface of the corrugated structure, 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 increased absolute humidity; and The HME is removably or permanently secured within the plenum chamber of the patient interface during the flow of breathable gas.

8. A method of manufacturing a heat and moisture exchanger (HME) for humidifying a flow of breathable gas delivered through 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 a flow of breathable gas through the HME and along a surface of the corrugated structure; as well as The number of corrugations forming the channel is adjusted to increase the flow rate of the flow of breathable gas through the channel to achieve a desired flow impedance.

9. A method of manufacturing a heat and moisture exchanger (HME) having increased surface area per unit volume to achieve a desired humidification performance for humidifying a flow of breathable gas, the method comprising: Determining desired humidification performance; corrugating at least a portion of the HME to form a plurality of channels to allow a flow of breathable gas through the HME and along a surface of the corrugated structure; adjusting the number of corrugations forming the channels to increase the surface area per unit volume of the HME; as well as The HME is stacked into corrugated layers to further increase the surface area per unit volume of the HME to achieve the desired humidification performance.

10. A method of manufacturing for increasing the humidification performance of a heat and moisture exchanger (HME) to humidify a flow of breathable gas delivered by a patient interface to a desired level, the method comprising: Determining the required humidification performance of the HME; Laser cutting multiple channels through the HME to increase the surface area per unit volume, thereby increasing the humidification performance of the HME; as well as The number of channels is increased by laser cutting until the desired humidification performance is achieved.

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