Valve Assembly

Abstract

A combined one-way inhalation and exhalation valve assembly is provided for controlling airflow in a respiratory treatment system. The valve assembly includes a housing including a valve inlet, a valve outlet, and at least one ventilation opening, and a diaphragm sealingly connected to the housing at an outer periphery of the diaphragm, the diaphragm dividing the housing into a) an upstream portion in fluid communication with the valve inlet and b) a downstream portion in fluid communication with the valve outlet. The diaphragm has a circular, oval, elliptical, or stadium shape. An inner portion of the diaphragm defines a one-way inhalation valve. An outer portion of the diaphragm defines an exhalation valve. A method of characterizing ventilation flow in a respiratory treatment system including such valves is also described.

Description

[Technical field]

[0001] 1. Technical Field 1.1 Technical field The present invention relates to one or more of screening, diagnosis, monitoring, treatment, prevention and amelioration of respiratory related disorders. The present invention also relates to medical devices or apparatus and uses thereof. [Background technology]

[0002] 1.2 Background Technology 1.2.1 Human respiratory system and its disorders The body's respiratory system facilitates gas exchange. The nose and mouth form the entrance to a patient's airways.

[0003] The airways contain a series of branching tubes that become narrower, shorter, and more numerous the deeper they go into the lungs. The primary function of the lungs is gas exchange, allowing oxygen to move from inspired air into the venous blood and carbon dioxide to move in the opposite direction. The trachea divides into right and left main bronchi, which further divide and eventually become terminal bronchioles. The bronchi make up the conducting airways and do not participate in gas exchange. The airways further divide into respiratory bronchioles and ultimately into alveoli. The alveolar region of the lungs is where gas exchange occurs and is called the respiratory zone. See Respiratory Physiology by John B. West, Lippincott Williams & Wilkins (9th Edition, 2012).

[0004] There are a variety of respiratory disorders, and specific disorders may be characterized by specific events, such as apnea, hypopnea, and hyperpnea.

[0005] Examples of respiratory disorders include obstructive sleep apnea (OSA), Cheyne-Stokes respiration (CSR), respiratory insufficiency, obesity hyperventilation syndrome (OHS), chronic obstructive pulmonary disease (COPD), neuromuscular disorders (NMD), and chest wall disorders.

[0006] Obstructive sleep apnea (OSA) is a form of sleep-disordered breathing (SDB) and is characterized by events involving the obstruction or closure of the upper airway during sleep. It is the result of an abnormally small upper airway combined with the normal loss of muscle tone in the area of ​​the tongue, soft palate, and posterior oropharyngeal wall during sleep. This condition forces affected patients to stop breathing, usually for 30 to 120 seconds, and in some cases 200 to 300 times each night. It often causes excessive daytime sleepiness and can lead to cardiovascular disease and brain damage. The syndrome is a common disorder, especially in middle-aged, overweight men, but affected individuals may not be aware of the problem. See U.S. Pat. No. 4,944,310 (Sullivan).

[0007] Cheyne-Stokes respiration (CSR) is another form of sleep-disordered breathing. CSR is a disorder of the patient's respiratory regulator, which has rhythmically alternating periods of waxing and waning ventilation, known as CSR cycles. CSR is characterized by repeated deoxygenation and reaeration of arterial blood. CSR can be harmful because of repeated hypoxia. In some patients, CSR is associated with repeated awakenings from sleep, which causes severe insomnia, increased sympathetic activity, and increased afterload. See U.S. Patent No. 6,532,959 (Berthon-Jones).

[0008] Respiratory failure is a general term for breathing problems that occur when the lungs are unable to take in enough oxygen or expel enough CO2 to meet the patient's needs. Respiratory failure can include any or all of the following problems:

[0009] Patients with respiratory insufficiency (a type of respiratory failure) may experience abnormal shortness of breath during exercise.

[0010] Obesity hypoventilation syndrome (OHS) is defined as the combination of severe obesity and awake chronic hypercapnia with no other known causes of hypoventilation. Symptoms include dyspnea, morning headache, and excessive daytime sleepiness.

[0011] Chronic obstructive pulmonary disease (COPD) encompasses any of a group of lower airway disorders that share certain characteristics. These include increased resistance to air movement, prolongation of the expiratory phase of breathing, and loss of normal elasticity of the lungs. Examples of COPD include emphysema and chronic bronchitis. Causes of COPD include chronic smoking (primary risk factor), occupational exposure, air pollution, and genetic factors. Symptoms include dyspnea on exertion, chronic cough, and sputum production.

[0012] Neuromuscular diseases (NMD) is a broad term that encompasses numerous diseases and illnesses that impair muscle function directly through intrinsic muscle pathology or indirectly through neuropathology. Some NMD patients are characterized by progressive muscle impairment that leads to inability to walk, wheelchair use, difficulty swallowing, respiratory muscle weakness, and ultimately death due to respiratory failure. Neuromuscular disorders can be divided into fast-progressive and slow-progressive: (i) fast-progressive disorders: characterized by muscle impairment that worsens over months and leads to death within a few years (e.g., amyotrophic lateral sclerosis (ALS) and teenage Duchenne muscular dystrophy (DMD)); (ii) variable or slow-progressive disorders: characterized by muscle impairment that worsens over years but only mildly reduces life expectancy (e.g., limb-girdle, facioscapulohumeral, and myotonic muscular dystrophies). Symptoms of respiratory failure in NMD include increasing general weakness, difficulty swallowing, shortness of breath on exertion and at rest, fatigue, drowsiness, morning headaches, and difficulty concentrating and mood changes.

[0013] Chest wall disorders are a group of thoracic deformities that result in ineffective connection between the respiratory muscles and the rib cage. The disorders are usually characterized by restrictive disorders and share the potential for long-term hypercapnic respiratory failure. Scoliosis and / or kyphoscoliosis can cause severe respiratory failure. Symptoms of respiratory failure include exertional dyspnea, peripheral edema, orthopnea, recurrent chest infections, morning headache, fatigue, poor quality of sleep, and anorexia.

[0014] A variety of therapies have been used to treat or ameliorate such diseases, and in addition, otherwise healthy individuals may utilize such therapies to prevent the development of respiratory disorders, but these suffer from a number of deficiencies.

[0015] 1.2.2 Therapy A variety of respiratory therapies (e.g., continuous positive airway pressure (CPAP) therapy, non-invasive ventilation (NIV), invasive ventilation (IV), and high-flow therapy (HFT)) have been used to treat one or more of the aforementioned respiratory disorders.

[0016] 1.2.2.1 Respiratory pressure therapy Respiratory pressure therapy is the application of an air supply to the entrance to the airways at a controlled target pressure that is nominally positive relative to atmosphere throughout the patient's respiratory cycle (as opposed to negative pressure therapies such as tank ventilators or positive-negative extracorporeal ventilators (cuirass)).

[0017] Continuous positive airway pressure (CPAP) therapy has been used to treat obstructive sleep apnea (OSA). The mechanism of action is that the continuous positive airway pressure acts as a pneumatic splint, such as by pushing the soft palate and tongue forward and backward against the posterior oropharyngeal wall, and may prevent the closure of the upper airway. Because treatment of OSA with CPAP therapy can be voluntary, patients may choose not to comply with the therapy if they find one or more of the following about the devices used to deliver such therapy: uncomfortable, difficult to use, expensive, and poor aesthetics.

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

[0019] Invasive ventilation (IV) provides ventilatory support to patients who can no longer breathe effectively on their own and may be provided using a tracheotomy tube. Some forms may improve the comfort and effectiveness of these treatments.

[0020] 1.2.2.2 Flow therapy Not all respiratory therapies aim to deliver a prescribed therapeutic pressure. Some respiratory therapies aim to deliver a prescribed respiratory volume, perhaps by delivering an inspiratory flow profile superimposed on a positive baseline pressure for a target duration. In other cases, the interface to the patient's airway is "open" (unsealed) and the respiratory therapy may only supplement the patient's own spontaneous breathing with a flow of regulated or enriched gas. In one example, high flow therapy (HFT) is the provision of a continuous, heated, humidified air flow to the entrance to the airway through an unsealed or open patient interface at a "therapeutic flow" that can be held approximately constant throughout the respiratory cycle. The therapeutic flow is nominally set to exceed the patient's peak inspiratory flow. HFT has been used to treat OSA, CSR, respiratory failure, COPD and other respiratory disorders. One mechanism of action is that the high flow of air at the entrance to the airway improves ventilation efficiency by flushing or sweeping exhaled CO2 from the patient's anatomical dead space. Therefore, HFT is sometimes called Dead Space Therapy (DST). Other benefits may include increased warmth and humidification (possibly with a secretion management benefit) and the possibility of a gradual increase in airway pressure. As an alternative to a constant flow rate, the therapeutic flow rate may follow a profile that varies over the respiratory cycle.

[0021] Another form of flow therapy is long term oxygen therapy (LTOT) or supplemental oxygen therapy. A physician may prescribe a continuous flow of oxygen-enriched air at a particular oxygen concentration (fraction of oxygen in ambient air, from 21% to 100%) delivered to the patient's airways at a particular flow rate (e.g., 1 liter per minute (LPM), 2 LPM, 3 LPM, etc.).

[0022] 1.2.3 Respiratory Therapy Systems These respiratory therapies may be provided by respiratory therapy systems or devices. Such systems and devices may also be used to screen, diagnose, or monitor disease without treating it.

[0023] The respiratory therapy system may include a respiratory pressure therapy device (RPT device), an air circuit, a humidifier, a patient interface, an oxygen source, and data management.

[0024] 1.2.4 Patient Interface The patient interface may be used to provide the wearer with an interface to the respiratory appliance, for example by providing airflow to an entrance to the airway. The airflow may be provided via a mask to the nose and / or mouth, a tube to the mouth, or a tracheotomy tube to the patient's trachea. Depending on the therapy being applied, the patient interface may facilitate gas delivery at a pressure sufficiently different from ambient pressure, for example, about 10 cmH2O positive pressure relative to ambient pressure, by forming a seal with, for example, a portion of the patient's face, to effectively perform the therapy. For other forms of therapy, such as oxygen delivery, the patient interface may not include sufficient sealing properties to facilitate delivery of a gas supply to the airway at a positive pressure of about 10 cmH2O. For flow therapy, such as nasal HFT, the patient interface is positioned to insufflate the nares but not to completely seal. One example of such a patient interface is a nasal cannula.

[0025] Certain other mask systems may be functionally inadequate in the art, for example masks that are purely decorative may not be able to maintain adequate pressure, mask systems used for underwater swimming or diving may be constructed to protect against water intrusion from higher pressures from the outside, but not to maintain internal air at pressures higher than ambient.

[0026] For example, a particular mask may not be clinically suitable for the present invention if it blocks airflow through the nose and only allows airflow through the mouth.

[0027] In certain masks, where the patient must insert part of the mask structure into their mouth to create and maintain a seal via the lips, this may be uncomfortable or impractical for the present invention.

[0028] Certain masks may be impractical for use while sleeping (eg, when sleeping on one's side in bed with head resting on a pillow).

[0029] Respiratory Pressure Therapy (RPT) Devices Respiratory pressure therapy (RPT) devices can be used individually or as part of a system to deliver one or more of the numerous therapies discussed above, such as by operating the device to generate an airflow for delivery to an interface to the airway. The airflow can be pressure controlled (for respiratory pressure therapy) or flow controlled (for flow therapy such as HFT). Thus, RPT devices can also function as flow therapy devices. Examples of RPT devices include CPAP devices and ventilators.

[0030] Air pressure generators are known in a variety of applications, such as industrial-scale ventilation systems. However, air pressure generators for medical applications have specific requirements that are not met by more common air pressure generators (e.g., reliability, size and weight requirements of medical devices). In addition, even devices designed for medical treatment may suffer from deficiencies related to one or more of the following: comfort, noise, ease of use, effectiveness, size, weight, manufacturability, cost and reliability.

[0031] One example of a special requirement for a particular RPT device is acoustic noise.

[0032] Table 1 shows the noise output levels of conventional RPT devices (measured on one sample only at 10 cmH2O in CPAP mode using the test method specified in ISO3744).

[0033] [Table 1]

[0034] One known RPT device used to treat sleep disordered breathing is the S9 Sleep Therapy System manufactured by ResMed Limited. Another example of an RPT device is a ventilator. Ventilators (e.g., the ResMed Stellar® series of adult and pediatric ventilators) can provide invasive and non-invasive independent ventilatory support to a variety of patients to treat a number of diseases, including but not limited to NMD, OHS, and COPD.

[0035] The ResMed Elisee® 150 Ventilator and ResMed VSIII® Ventilator provide invasive and non-invasive support for dependent ventilation suitable for adult or pediatric patients to treat a number of illnesses. These ventilators provide volumetric and barometric ventilation modes using single or dual limb circuits. RPT devices typically include a pressure generator (e.g., an electric blower or compressed gas reservoir) and are configured to deliver airflow to the patient's airway. In some cases, the airflow may be delivered at positive pressure to the patient's airway. The outlet of the RPT device is connected via an air circuit to a patient interface as described above.

[0036] A device designer may be presented with a myriad of choices. Design criteria are often in conflict, meaning that certain design choices are unconventional or unavoidable. Furthermore, the comfort and effectiveness of certain aspects may be highly sensitive to small and subtle changes in one or more parameters.

[0037] A typical RPT device can consume up to 10W of power (excluding the power required to operate the humidifier). It is important to increase the efficiency of the device to minimise power consumption. This is important when the RPT is powered from a mains supply, but even more so when the device is battery operated, as high power consumption can reduce the time the RPT can operate from batteries when the RPT is portable, when mains power is not available (if the patient is camping), or when the mains power is disconnected.

[0038] The development of portable PAP devices, including wearable combination blower / mask systems, further calls for the use of smaller motors / turbines and power sources / batteries. However, compared to traditional PAP systems, these smaller systems generally have less pneumatic performance. One way to maintain a relatively high pneumatic performance is to optimize the performance of such systems by minimizing wasted energy and making the system more efficient. However, it is important to ensure that any change in any element of the system does not interfere with the remaining system elements and that the optimized system continues to be quiet, efficient, and does not cause inconvenience or increased effort to the user.

[0039] 1.2.4.1 Power supply RPT devices require a power source to operate. The power source adds volume and weight to the respiratory therapy system, especially if the system runs on batteries rather than mains power. Keeping power low again requires greater optimization, reducing inefficiencies and waste in the device's power management.

[0040] 1.2.4.2 Air Circuit An air circuit is a conduit or tube constructed and arranged to allow airflow to travel between two components of a respiratory therapy system (e.g., an RPT device and a patient interface) in use. In some cases, an air circuit may have separate branches for inhalation and exhalation. In other cases, a single-limb air circuit is used for both inhalation and exhalation.

[0041] 1.2.4.3 Humidifier Delivery of the airflow without humidification can lead to drying of the airway. When a humidifier is used with the RPT device and patient interface, humidified gas is produced, which minimizes drying of the nasal mucosa and creates humidified gas that increases comfort of the patient's airway. Additionally, in cooler climates, warm air applied to the facial area in and around the patient interface is generally more comfortable than cool air.

[0042] Various artificial humidification devices and systems are known, however, these may not meet the special requirements of a medical humidifier.

[0043] Medical humidifiers are typically used in locations where a patient may be sleeping or resting (e.g., in a hospital) to increase the humidity and / or temperature of an air stream relative to the ambient air when necessary. Bedside medical humidifiers may be small. Medical humidifiers may be configured to only humidify and / or heat the air stream delivered to the patient, without humidifying and / or heating the patient's immediate environment. For example, room-based systems (e.g., saunas, air conditioners, or evaporative coolers) may also humidify the air inhaled by the patient, but these systems may also humidify and / or heat the entire room, which may cause discomfort to the occupants. Additionally, medical humidifiers may have more stringent safety constraints than industrial humidifiers.

[0044] Although many medical humidifiers are known, these humidifiers suffer from one or more drawbacks: some medical humidifiers provide insufficient humidification, while others are difficult or inconvenient for the patient to use.

[0045] Data Management For clinical reasons, data may be obtained to determine whether a patient prescribed respiratory therapy is "compliant" (e.g., whether the patient is using his / her RPT device in accordance with one or more "compliance rules"). One example of a compliance rule for CPAP therapy may require a patient to use the RPT device for at least 4 hours per night for at least 21 days out of 30 consecutive days to be considered compliant. To determine patient compliance, a provider of the RPT device (e.g., a healthcare provider) may manually obtain data describing the patient's therapy with the RPT device, calculate a usage rate over a period of time, and compare this to the compliance rules. If the healthcare provider determines that the patient used his / her RPT device in accordance with the compliance rules, the healthcare provider may notify a third party that the patient is compliant.

[0046] There may be other aspects of a patient's therapy that would benefit from communication of therapy data to third parties or external systems.

[0047] Existing processes for communicating and managing such data can be one or more of: costly, time consuming, and error prone.

[0048] 1.2.4.4 Ventilation technology Some forms of treatment systems may include a vent to push out exhaled carbon dioxide, which may allow gas flow from an interior space of the patient interface (e.g., a plenum chamber) to an exterior of the patient interface (e.g., the surroundings).

[0049] The vent may include an orifice through which gas may flow when the mask is in use. In many cases, gas is continuously exhausted from the vent at all points during the patient's breathing cycle.

[0050] Many such vents are noisy. In others, they may become blocked when in use, resulting in insufficient pumping. Some vents may disrupt the sleep of the patient's bed companion 1100, for example, due to noise or airflow concentration.

[0051] ResMed Limited has developed several improved mask ventilation technologies, see International Patent Application Publication No. WO 1998 / 034,665, International Patent Application Publication No. WO 2000 / 078,381, U.S. Patent No. 6,581,594, U.S. Patent Application Publication No. 2009 / 0050156, U.S. Patent Application Publication No. 2009 / 0044808.

[0052] 1.2.5 Screening, diagnostic, and surveillance systems Polysomnography (PSG) is a conventional system for diagnosing and monitoring cardiopulmonary diseases, which typically requires expert clinical staff for system application. In PSG, typically 15-20 contact sensors are placed on the patient to record various body signals such as electroencephalography (EEG), electrocardiography (ECG), electrooculography (EOG), and electromyography (EMG). PSG for sleep-disordered breathing requires the patient to be observed for two nights in the clinic; the first night is purely diagnostic, and the second night is titration of treatment parameters by the clinician. Therefore, PSG is expensive and inconvenient. Screening / diagnosis / monitoring of sleep-disordered breathing is particularly unsuitable for home use.

[0053] In general, screening and diagnosis are the identification of disease by signs and symptoms of the disease. Screening usually gives a true / false result indicating whether a patient's SDB is severe enough to warrant further investigation, while diagnosis often provides clinically actionable information. Screening and diagnosis tend to be one-time procedures, whereas monitoring the course of a disease can continue indefinitely. Some screening / diagnostic systems are adapted for screening / diagnosis only, while some can be used for monitoring as well.

[0054] A clinical expert may adequately screen, diagnose, or monitor a patient based on visual observation of the PSG signal. However, there are situations where a clinical expert is not available or cannot be paid for. Different clinical experts may have different opinions about a patient's condition. In addition, a clinical expert may apply different criteria at different times. Summary of the Invention [Means for solving the problem]

[0055] The present invention relates to the provision of a medical device for use in screening, diagnosing, monitoring, ameliorating, treating or preventing respiratory disorders, having one or more of improved comfort, cost, effectiveness, ease of use and manufacturability.

[0056] A first aspect of the invention relates to a device for use in screening, diagnosing, monitoring, ameliorating, treating or preventing a respiratory disorder.

[0057] Another aspect of the invention relates to methods used to screen for, diagnose, monitor, ameliorate, treat or prevent respiratory disorders.

[0058] It is an aspect of certain aspects of the present invention to provide a method and / or device for improving patient compliance with respiratory therapy.

[0059] One aspect of the present invention is a valve assembly.

[0060] Another aspect of the present invention is an air circuit that includes a valve assembly.

[0061] Another aspect of the present invention is a method for characterizing ventilation flow in a respiratory treatment system.

[0062] Another aspect of the present invention is a method for estimating ventilation flow from a patient interface in the presence of an expiratory actuated valve.

[0063] Another aspect of the present invention is a system for treating respiratory disorders including a patient interface, an air circuit, and an RPT device, the air circuit including a valve assembly.

[0064] Another aspect of the present invention is a system for treating disordered breathing in a patient, including a patient interface, an air circuit, and an RPT device, the RPT device being controlled to reduce output when patient exhalation is detected.

[0065] In some examples, the system includes a combination one-way inhalation valve-exhalation discharge valve between the RPT device and the patient, and the RPT device reduces output when it detects that pressure on the patient side of the one-way inhalation valve and the exhalation discharge valve exceeds a preselected pressure.

[0066] One aspect of one form of the present invention is a portable RPT device that can be carried by a person, for example, around their home.

[0067] Another aspect of the present invention is a respiratory therapy device for delivering pressurized air to the entrance of a patient's airways. a combination one-way inhalation valve-exhalation valve assembly for controlling airflow within the system, the system being configured to maintain a treatment pressure within a range suitable for treating a respiratory disorder; The combination one-way intake valve-exhale discharge valve assembly is a housing including a valve inlet, a valve outlet, and at least one ventilation opening; a diaphragm sealingly connected to the housing at an outer periphery of the diaphragm and dividing the housing into a) an upstream portion in fluid communication with the valve inlet and b) a downstream portion in fluid communication with the valve outlet; the diaphragm has a circular, oval, elliptical, or stadium shape; The inner portion of the diaphragm defines a one-way intake valve, the one-way intake valve comprising: - permitting flow from the valve inlet to the valve outlet when the pressure in the upstream portion of the housing exceeds the pressure in the downstream portion of the housing; and - configured to reduce or substantially prevent flow from the valve inlet to the valve outlet when the pressure in the downstream portion is greater than the pressure in the upstream portion; the outer portion of the diaphragm defines an expiratory release valve, the expiratory release valve comprising: - allowing flow from the downstream portion of the housing through at least one ventilation opening to the ambient atmosphere when the pressure in the downstream portion exceeds the pressure in the upstream portion; and configured to reduce or substantially prevent flow from the downstream portion of the housing through the at least one ventilation opening to the ambient atmosphere when the pressure in the upstream portion exceeds the pressure in the downstream portion.

[0068] In various instances, aa) the diaphragm has an elongated shape and a ratio of the major axis length of the diaphragm to the minor axis length of the diaphragm is at least 4:3; b) the one-way valve structure is configured as a duckbill valve and a base of the duckbill valve has a length dimension substantially parallel to the major axis of the diaphragm and a width dimension substantially parallel to the minor axis of the diaphragm, the length being greater than the width; and c) the ratio of the length to the width is at least 1.5:1 or 2:1; d) the diaphragm includes an outer retention flange; e) the diaphragm has a cylindrical wall and the retention flange is at one end of the cylindrical wall; f) a first portion of the diaphragm has at least one material or physical property different from adjacent portions of the diaphragm; g) the first portion of the diaphragm is made of a material different from adjacent portions; h) the diaphragm is integrally made of a single material; i) the diaphragm has regions of different thicknesses, one of the regions being at least twice as thick as the other regions; j) one of the regions being 2-8 times as thick as the other regions; k) the one-way inhalation valve has a first region having a first thickness and a second region having a second thickness adjacent to the first region; l) the exhalation release valve has a first region having a first thickness and a second region having a second thickness adjacent to the first region; m) the diaphragm has only one axis of symmetry; n) the at least one ventilation opening is at least one axially extending aperture; a plurality of ventilation openings spaced apart about an outer periphery of a downstream portion of the housing; o) the downstream portion of the housing includes a valve outlet, the diaphragm including a pair of lips that are forced toward each other to seal a path to the patient interface port when pressure in the downstream portion exceeds pressure in the upstream portion, the pair of lips forming an opening for passing airflow toward the patient interface port inlet when pressure in the upstream portion of the housing exceeds pressure in the downstream portion; p) a flow guide is provided at each ventilation opening, each flow guide configured to avoid or minimize i) sharp corners, ii) acute angles, and iii) sudden expansion of exhaled gases flowing from the valve outlet to a corresponding ventilation opening when pressure in the downstream portion exceeds pressure in the upstream portion; q) each flow guide includes a ramp portion that guides the exhaled airflow to an inlet of the ventilation opening; and / or r) each flow guide includes sidewall portions provided on either side of each corresponding ramp portion. b. Another aspect of the invention is a patient interface system for delivering airflow generated by a blower to a patient, comprising any of the valves described above. c. Another aspect of the present invention is a respiratory therapy system for delivering pressurized air to an entrance of a patient's airways, comprising: d. A blower for generating pressurized air; e. a patient interface for sealing the delivery of pressurized air to the patient's airway; f. A patient interface system including at least the combination one-way inhalation valve-exhalation valve assembly described above for controlling air flow to the patient interface.

[0069] In some examples, the system comprises: a) further comprising a pressure sensor configured to measure pressure in the patient interface, the system controlling the blower based on data from the pressure sensor; b) reducing flow from the blower when the pressure sensor detects a patient's exhalation; c) further comprising a conduit for delivering pressurized air to the patient interface, the combination valve being included in the conduit or patient interface; d) comprising a portable integrated blower / patient interface system wearable on the patient's face or head; and / or f) configured to be powered by one or more batteries.

[0070] Another aspect of the invention is a method of characterizing ventilation flow in a respiratory therapy system for delivering pressurized air to an entrance of a patient's airways, the system including a combination one-way inhalation valve-exhalation discharge valve as described above, the method comprising: a) performing at least one simulated breathing cycle using a respiratory treatment system; b) measuring the flow through the valve ventilation section, the pressure upstream of the valve, and the pressure downstream of the valve during at least one simulated breathing cycle; c) plotting ventilation flow versus the ratio of pressures on either side of the diaphragm; d) identifying whether there are boundary points that divide the plotted data into one or more continuous zones based on trends in the data; e) deriving an equation for a best fit curve for the data of each identified zone; f) deriving at least coefficients and constants from the fitting equations that characterize the corresponding function between pressure ratio and ventilation flow for each zone, at least at the first therapeutic pressure.

[0071] In some examples, a) the pressure ratio is the ratio of the pressure upstream of the valve to the pressure downstream of the valve; b) the method further comprises repeating steps a)-e) for at least one second treatment pressure to derive coefficients and constants characterizing each function for each zone at the at least one second treatment pressure from each fit equation; c) the method further comprises interpolating the derived coefficients and constants to derive further coefficients and constants for treatment pressures other than the at least first and second treatment pressures; d) the method further comprises calculating a respective ventilation flow for each of the one or more treatment pressures for a given ratio of pressures upstream and downstream of the valve using the derived and / or interpolated coefficients and constants; and e) the method further comprises pre-calculating and tabulating the derived and interpolated coefficients for a number of different treatment pressures. and using the tabulated values ​​as a reference for less computationally intensive ventilation flow derivation under various pressures; f) the method further comprises using the derived ventilation flows to derive patient flows at corresponding therapeutic pressures; g) the method further comprises using the derived and / or tabled ventilation flows to derive patient flows at each therapeutic pressure; h) the method further comprises calculating patient flows at each therapeutic pressure using the derived and / or tabled ventilation flows; and / or i) the step of calculating the patient flows at each therapeutic pressure further comprises measuring a blower flow rate of the respiratory treatment system and calculating unexpected leakage at the patient interface; and / or i) the step of dividing the plotted data into a plurality of contiguous zones comprises dividing the plotted data into three contiguous zones.

[0072] Another aspect of one form of the present invention is a patient interface that is shaped or constructed to have a perimeter that is complimentary to that of the intended wearer.

[0073] One aspect of the present invention is a method for manufacturing a device.

[0074] One aspect of certain forms of the present invention is a medical device that is easy to use, for example, by individuals with no medical training, who lack good dexterity or insight, or who have limited experience in using medical devices of this type.

[0075] One aspect of one form of the present invention is a portable RPT device that can be carried by a person, for example, around their home.

[0076] One aspect of one embodiment of the present invention is a patient interface that can be cleaned in the patient's home, for example with soapy water, without the need for special cleaning equipment.One aspect of one embodiment of the present invention is a humidifier tank that can be cleaned in the patient's home, for example with soapy water, without the need for special cleaning equipment.

[0077] The above-described methods, systems, devices, and apparatus may be implemented to improve the functionality of processors of special purpose computers, respiratory monitors, and / or respiratory therapy devices, etc. Additionally, the above-described methods, systems, devices, and apparatus may provide improvements in the art of automated management, monitoring, and / or treatment of respiratory conditions, including, for example, sleep-disordered breathing.

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

[0079] Other features of the present invention will become apparent in view of the information contained in the following detailed description, abstract, drawings and claims. [Brief description of the drawings]

[0080] The present invention is illustrated by way of non-limiting example in the diagrammatic views of the accompanying drawings in which like reference numbers refer to similar elements including: 3.1 Respiratory Therapy Systems [Figure 1A] A system is shown including a patient 1000 wearing a patient interface 3000. The system takes the form of nasal pillows and receives positive pressure air supplied from an RPT device 4000. Air from the RPT device 4000 is humidified in a humidifier 5000 and delivered to the patient 1000 through an air circuit 4170. A bed companion 1100 is also shown. The patient is sleeping in a supine sleep position. [Figure 1B] The system is shown to include a patient 1000 wearing a patient interface 3000 in the form of a nasal mask that receives air at positive pressure supplied from an RPT device 4000. Air from the RPT device is humidified in a humidifier 5000 and delivered along an air circuit 4170 to the patient 1000. [Figure 1C] The system is shown to include a patient 1000 wearing a patient interface 3000 in the form of a full face mask that receives air at positive pressure supplied from an RPT device 4000. The air from the RPT device is humidified in a humidifier 5000 and delivered along an air circuit 4170 to the patient 1000. The patient is sleeping in a lateral sleep position. 3.2 Respiratory System and Facial Anatomy [Figure 2A] 3.3 Patient Interface [Figure 3A] 3 shows a patient interface in the form of a nasal mask according to one embodiment of the present invention. [Figure 4A] 1 illustrates an RPT device according to one embodiment of the present invention. [Figure 4B]1 is a schematic diagram of a pneumatic path of an RPT device according to one embodiment of the present invention. Upstream and downstream directions are indicated with reference to the blower and the patient interface. Regardless of the actual flow direction at any particular moment, the blower is defined as being upstream of the patient interface, and the patient interface is defined as being downstream of the blower. Items in the pneumatic path between the blower and the patient interface are downstream of the blower and upstream of the patient interface. [Figure 4C] FIG. 2 is a schematic diagram of electrical components of an RPT device according to one embodiment of the present invention. [Figure 4D] FIG. 2 is a schematic diagram of an algorithm implemented within an RPT device according to one embodiment of the present invention. [Figure 4E] 4D according to one embodiment of the present invention. [Figure 5A] 1 shows an isometric view of a humidifier according to one embodiment of the present invention. [Figure 5B] An isometric view of a humidifier according to one embodiment of the present invention is shown, showing the humidifier reservoir 5110 removed from the humidifier reservoir dock 5130. 3.6 Breath Waveform [Figure 6] A model of a typical respiratory waveform for a sleeping human is shown. 3.7 Patient Interface According to the Invention [Figure 7] 1 illustrates a system including a patient interface, an air circuit, and an RPT device, according to one embodiment of the present invention. [Figure 8] 1 shows a schematic cross-sectional view of a valve assembly according to one aspect of the present invention. [Figure 9] 1 shows a perspective view of a valve member according to one aspect of the present invention. [Figure 10] 11 shows a schematic cross-section of the valve member of FIG. 10 with the duckbill valve in a closed configuration. [Figure 11] 1 shows a plan view of a valve member according to one aspect of the present invention. [Figure 12] FIG. 12 shows a side view of the valve member of FIG. [Figure 13]11 shows a schematic cross-section of the valve member of FIG. 10 with a duckbill valve in an open configuration. [Figure 14] 9 shows an exploded cross-sectional view of the valve assembly of FIG. 8. [Figure 15] 9 illustrates a cross-sectional view of the valve assembly of FIG. 8 with the upstream housing portion separated from the downstream housing portion. [Figure 16] 1 shows a schematic cross-sectional view of a valve assembly with the duckbill valve open and the diaphragm blocking flow to the vent, according to one embodiment of the present invention. [Figure 17] FIG. 17 shows an enlarged view of the diaphragm and vent of the valve assembly of FIG. [Figure 18] FIG. 9 shows a schematic cross-sectional view of the valve assembly of FIG. 8 with the duckbill valve closed and the diaphragm allowing flow to the vent. [Figure 19] FIG. 19 shows an enlarged view of the diaphragm and vent of the valve assembly of FIG. [Figure 20] 1 shows a schematic cross-sectional view of a valve assembly in which a diaphragm allows flow to a vent and a duckbill valve allows a small amount of flow, according to one embodiment of the present invention. [Figure 21] 1 shows an enlarged schematic cross-sectional view of a valve assembly according to one embodiment of the present invention, with the membrane shown in both a ventilated (dashed line) and non-ventilated configuration. [Figure 22] 1 shows a simplified respiratory curve for use with the valve member of the present invention. [Figure 23] 4 shows a simplified ventilation flow curve for use with the valve member of the present invention. [Figure 24] 1 illustrates an open duckbill valve and simulated flow through the duckbill valve, according to one embodiment of the present invention. [Diagram 25] 13 illustrates an example of an alternative form of a valve member without a duckbill valve, with exemplary portions of different thickness. [Figure 26] 1 is a flow chart and formulas relating to characteristics of a system for treating disordered breathing. [Figure 27]1 shows a portion of the experimental setup for performing a simulated breathing cycle. [Figure 28] 13 is a plot of ventilation flow versus pressure ratio for one form of the technique at one therapeutic pressure setting. [Figure 29] 13 is a graph showing estimated and measured patient flow versus time for a patient interface according to one embodiment of the present invention at a therapeutic pressure of 6 cmH2O. [Diagram 30] 13 is a graph showing estimated and measured patient flow versus time for a patient interface according to one embodiment of the present invention at a therapeutic pressure of 8 cmH2O. [Diagram 31] 13 is a graph showing estimated and measured patient flow versus time for a patient interface according to one embodiment of the present invention at a therapeutic pressure of 12 cmH2O. [Diagram 32] FIG. 1 is a perspective view of a passive humidifier according to one embodiment of the present invention. [Diagram 33] FIG. 33 is an exploded view of the passive humidifier of FIG. 32. [Diagram 34] 2 shows a schematic cross-sectional view of a valve assembly according to another aspect of the present invention. [Diagram 35] FIG. 35 shows a top perspective view of the downstream housing portion of the valve assembly of FIG. [Diagram 36] FIG. 9 illustrates a top perspective view of a downstream housing portion of the alternative valve assembly of FIG. 8. [Figure 37] 1 shows a perspective view of a valve member according to one aspect of the present invention. [Figure 38] 1 shows a perspective view of a valve member according to one aspect of the present invention. [Figure 39] 1 shows a perspective view of a valve member according to one aspect of the present invention. [Diagram 40] 1 shows a side perspective view of a valve member according to one aspect of the present invention. [Diagram 41] 1 is a flow chart illustrating steps in a method for characterizing ventilation flow in a respiratory treatment system, according to one aspect of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0081] Before describing the present invention in further detail, it is to be understood that the present invention is not limited to the particular examples described herein, as these may vary. It is also to be understood that the terminology used in this disclosure is for the purpose of describing only the particular examples discussed herein, and is not intended to be limiting.

[0082] The following description is provided in conjunction with various examples that may share one or more common characteristics and / or features. It should be understood that one or more features of any one example may be combined with one or more features of another or other example. In addition, any single feature or combination of features in any of these examples may be arranged into further examples.

[0083] 4.1 Therapy In one form, the invention includes a method of treating disordered breathing comprising applying positive pressure to the entrance of the airways of a patient 1000 .

[0084] In a particular example of the invention, a supply of air at positive pressure is provided to the patient's nasal passages via one or both of the nostrils.

[0085] In certain instances of the present invention, mouth breathing is restricted, limited or prevented.

[0086] 4.2 Respiratory Therapy Systems In one form, the present invention includes a respiratory therapy system for treating respiratory disorders. The respiratory therapy system may include an RPT device 4000 that provides an air flow to a patient 1000 via an air circuit 4170 and a patient interface 3000.

[0087] One form of such a system is shown in Figure 7. The example shown in Figure 7 is a portable integrated blower / patient interface system that can be worn on the face or head of a patient. The example shown in Figure 7 may be battery powered by one or more batteries.

[0088] Patient Interface As shown in FIG. 3A, a non-invasive patient interface 3000 according to one embodiment of the present invention includes as functional aspects a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilizing structure 3300, a ventilation section 3400, a form of connection port 3600 for connecting to an air circuit 4170, and a forehead support 3700. In some forms, the functional aspects can 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 positioned to surround the entrance(s) to the patient's 1000 airway to maintain positive pressure at the entrance to the airway. As such, the sealed patient interface 3000 is suitable for delivery of positive pressure therapy.

[0089] RPT Devices The RPT device 4000 according to one aspect of the present invention includes mechanical, pneumatic, and / or electrical components and is configured to execute one or more algorithms 4300 (e.g., any of the methods described herein, in whole or in part). The RPT device 4000 may be configured to generate an airflow for delivery to a patient's airway to treat one or more of the respiratory ailments described elsewhere herein.

[0090] In one form, the RPT device 4000 is constructed and arranged to deliver air flow in the range of -20 L / min to +150 L / min while maintaining a positive pressure of at least 6 cmH2O, or at least 10 cmH2O, or at least 20 cmH2O.

[0091] The RPT device 4000 may have an outer housing 4010 formed in two portions, an upper portion 4012 and a lower portion 4014. Further, the outer housing 4010 may include one or more panel(s) 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 may include a handle 4018.

[0092] The air pressure path of the RPT device 4000 may include one or more air path components, such as an inlet air filter 4112, an inlet muffler 4122, a pressure generator 4140 (e.g., a blower 4142) capable of supplying air at positive pressure, an outlet muffler 4124, and one or more transducers 4270, such as a pressure sensor 4272 and a flow sensor 4274.

[0093] One or more of the pneumatic path items may be located in a removable unitary structure referred to as a pneumatic block 4020. The pneumatic block 4020 may be disposed within the outer housing 4010. In one form, the pneumatic block 4020 is supported by or formed as part of the chassis 4016.

[0094] The RPT device 4000 can have a power supply 4210, one or more input devices 4220, a central controller 4230, a therapy device controller 4240, a pressure generator 4140, one or more protection circuits 4250, a memory 4260, a transducer 4270, a data communication interface 4280, and one or more output devices 4290. The electrical components 4200 can be implemented on a single printed circuit board assembly (PCBA) 4202. In an alternative, the RPT device 4000 can include more than one PCBA 4202.

[0095] Mechanical and pneumatic components of RPT devices The RPT device may include one or more of the following components in an integrated unit: In one alternative, one or more of the following components may each be located as a separate unit.

[0096] Air filter(s) An RPT device according to one aspect of the present invention may include one air filter 4110 or multiple air filters 4110.

[0097] In one form, the inlet air filter 4112 is located upstream of the pressure generator 4140 at the beginning of the air pressure path.

[0098] In one form, the outlet air filter 4114, for example an antibacterial filter, is located between the outlet of the pneumatic block 4020 and the patient interface 3000.

[0099] Muffler(s) An RPT device according to one aspect of the present invention may include a muffler 4120 or multiple mufflers 4120.

[0100] In one form of the invention, the inlet muffler 4122 is located in the pneumatic path upstream of the pressure generator 4140 .

[0101] In one form of the invention, the outlet muffler 4124 is located in the pneumatic path between the pressure generator 4140 and the patient interface 3800.

[0102] 4.2.1.1 Pressure generator In one form of the invention, the pressure generator 4140 for generating an air flow or supply at positive pressure is a controllable blower 4142. For example, the blower 4142 may include a brushless DC motor 4144 having one or more impellers. The impellers may be arranged in a volute. The blower may be capable of delivering a supply of air at a rate of, for example, up to about 120 liters / min, at a positive pressure in the range of about 4 cmH2O to about 20 cmH2O, or in other forms up to about 30 cmH2O when delivering respiratory pressure therapy. The blower may be one of those described in any one of U.S. Pat. Nos. 7,866,944, 8,638,014, 8,636,479, and PCT Patent Application Publication No. WO 2013 / 020167, the contents of which are incorporated herein by reference in their entirety.

[0103] The pressure generator 4140 can be under the control of the therapy device controller 4240 .

[0104] In other forms, pressure generator 4140 may be a piston-driven pump, a pressure regulator connected to a high pressure source (eg, a pressurized air reservoir), or a bellows.

[0105] Transducer(s) The transducer may be internal to the RPT device or external to the RPT device. An external transducer may, for example, be located on or form part of the air circuit (e.g., the patient interface). An external transducer may take the form of a non-contact sensor, for example a Doppler radar motion sensor that transmits or transfers data to the RPT device.

[0106] In one form of the invention, one or more transducers 4270 may be located upstream and / or downstream of pressure generator 4140. The one or more transducers 4270 may be constructed and arranged to generate a signal representative of a characteristic of the airflow at that point in the pneumatic path, such as flow rate, pressure, or temperature.

[0107] In one form of the invention, the one or more transducers 4270 may be located proximate to the patient interface 3000.

[0108] In one form, the signal from the transducer 4270 may be filtered, such as by low-pass filtering, high-pass filtering, or band-pass filtering.

[0109] Flow Sensor The flow sensor 4274 according to the present invention may be based on a differential pressure transducer, for example the SDP600 series differential pressure transducer from SENSIRION.

[0110] In one form, a signal generated by the flow sensor 4274 and representative of the flow rate is received by the central controller 4230.

[0111] 4.2.1.1.1 Pressure Sensors A pressure sensor 4272 according to the present invention is positioned in fluid communication with the pneumatic path. Examples of suitable pressure sensors include transducers from the HONEYWELL ASDX series. Other suitable pressure sensors are transducers from the GENERAL ELECTRIC NPA series.

[0112] In one form, a signal generated by the pressure sensor 4272 and representative of the pressure is received by the central controller 4230.

[0113] Motor Speed ​​Transducer In one form of the invention, the motor speed transducer 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 sensor 4276 can be provided to the therapy device controller 4240. The motor speed transducer 4276 can be, for example, a speed sensor such as a Hall effect sensor.

[0114] Anti-spillback valve In one form of the invention, an anti-spillback valve 4160 may be located between the humidifier 5000 and the pneumatic block 4020. The anti-spillback valve 4160 is constructed and arranged to reduce the risk of water flowing upstream from the humidifier 5000, for example to the motor 4144.

[0115] RPT Device Electrical Components Power Supply The power supply 4210 may be located inside or outside the external housing 4010 of the RPT device 4000.

[0116] In one form of the invention, the power supply 4210 provides power only to the RPT device 4000. In another form of the invention, the power supply 4210 provides power to both the RPT device 4000 and the humidifier 5000.

[0117] Input devices In one form of the invention, 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 or software devices accessible via a touch screen. In one form, the buttons, switches, or dials may be physically connected to the external housing 4010, and in another form, may be in wireless communication with a receiver electrically connected to the central controller 4230.

[0118] In one form, the input device 4220 may be constructed and arranged to allow a person to select values ​​and / or menu options.

[0119] Central Controller In one form of the invention, the central controller 4230 is one or more processors suitable for controlling the RPT device 4000.

[0120] Suitable processors may include x86 INTEL processors, processors based on ARM Holdings' ARM® Cortex®-M processors (e.g., ST MICROELECTRONIC's STM32 series of microcontrollers). In certain alternative embodiments of the invention, 32-bit RISC CPUs such as the ST MICROELECTRONICS STR9 series of microcontrollers manufactured by TEXAS INSTRUMENTS, or 16-bit RISC CPUs such as processors from the MSP430 family of microcontrollers may also be suitable.

[0121] In one form of the invention, the central controller 4230 is a dedicated electronic circuit.

[0122] In one form, the central controller 4230 is an application specific integrated circuit. In another form, the central controller 4230 includes discrete electronic components.

[0123] The central controller 4230 may be configured to receive input signal(s) from one or more transducers 4270, one or more input devices 4220, and the humidifier 5000.

[0124] The central controller 4230 may be arranged to provide output signal(s) to one or more of the output device 4290, the therapy device controller 4240, the data communication interface 4280, and the humidifier 5000.

[0125] In some forms of the invention, the central controller 4230 is configured to implement one or more methods described herein, e.g., one or more algorithms 4300, which may be implemented by processor control instructions represented as a computer program stored in a non-transitory computer-readable storage medium (e.g., memory 4260). In some forms of the invention, the central controller 4230 may be integrated into the RPT device 4000. However, in some forms of the invention, some methodologies may be performed by a remotely located device. For example, the remotely located device may determine ventilator control settings or detect respiratory-related events by analysis of stored data (e.g., from any of the sensors described herein).

[0126] clock The RPT device 4000 may include a clock 4232 connected to the central controller 4230 .

[0127] Therapy Device Controller In one form of the invention, the therapy device controller 4240 is a therapy control module 4330 that forms part of the algorithm 4300 executed by the central controller 4230.

[0128] In one form of the invention, the therapy device controller 4240 is a dedicated motor control integrated circuit. For example, in one form, the MC33035 brushless DC motor controller manufactured by ONSEMI is used.

[0129] protection circuit The one or more protection circuits 4250 according to the present invention may include electrical protection circuits, temperature and / or pressure safety circuits.

[0130] Memory According to one aspect of the invention, the RPT device 4000 includes a memory 4260, such as a 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.

[0131] Memory 4260 may be located on PCBA 4202. Memory 4260 may be in the form of EEPROM or NAND flash.

[0132] Additionally or alternatively, the RPT device 4000 includes a form of removable memory 4260, such as a memory card manufactured in accordance with the Secure Digital (SD) standard.

[0133] In one form of the invention, the memory 4260 functions as a non-transitory computer-readable storage medium on which computer program instructions representing one or more methodologies described herein, such as one or more algorithms 4300, are stored.

[0134] Data Communication Systems In one form of the invention, a data communications interface 4280 is provided and connected to the central controller 4230. The data communications interface 4280 may be connectable to a remote external communications network 4282 and / or a local external communications network 4284. The remote external communications network 4282 may be connectable to a remote external device 4286. The local external communications network 4284 may be connectable to a local external device 4288.

[0135] In one form, the data communication interface 4280 is part of the central controller 4230. In another form, the data communication interface 4280 is separate from the central controller 4230 and can include an integrated circuit or processor.

[0136] In one form, the remote external communications network 4282 is the Internet. The data communications interface 4280 may use wired communications (e.g., via Ethernet or fiber optics) or wireless protocols (e.g., CDMA, GSM, LTE) to connect to the Internet.

[0137] In one form, the local external communications network 4284 utilizes one or more communications standards (eg, Bluetooth or consumer infrared protocols).

[0138] In one form, the remote external device 4286 is one or more computers, such as a cluster of networked computers. In one form, the remote external device 4286 may be a virtual computer rather than a physical computer. In either case, such remote external equipment 4286 may be accessed by appropriately authorized personnel (e.g., a clinician).

[0139] The local external device 4288 may be a personal computer, a cell phone, a tablet, or a remote control.

[0140] Optional display and output devices including alarms An output device 4290 according to the present invention may take the form of one or more of a visual, auditory and tactile unit. The visual display may be a Liquid Crystal Display (LCD) or a Light Emitting Diode (LED) display.

[0141] Display Driver The display driver 4292 receives as input characters, symbols or images to be displayed on the display 4294 and converts them into commands that cause the display 4294 to display those characters, symbols or images.

[0142] display Display 4294 is configured to visually display characters, symbols, or images in response to commands received from display driver 4292. For example, display 4294 may be an eight-segment display, in which case display driver 4292 converts each character or symbol (e.g., the number "0") into eight logic signals indicating whether each of the eight segments should be activated to display the particular character or symbol.

[0143] RPT Device Algorithm As previously mentioned, in some forms of the invention, the central controller 4230 may be configured to implement one or more algorithms 4300 expressed as a computer program stored in a non-transitory computer-readable storage medium, such as the memory 4260. The algorithms 4300 are grouped into groups commonly referred to as modules.

[0144] In other aspects of the invention, the algorithm 4300 may be implemented in part or in its entirety by a controller of an external device (e.g., a local external device 4288 or a remote external device 4286). In such aspects, data representative of the input signals and / or intermediate algorithm outputs required for the portion of the algorithm 4300 executed on the external device may be communicated to the external device via a local external communications network 4284 or a remote external communications network 4282. In such aspects, the portion of the algorithm 4300 executed on the external device may be expressed as a computer program stored on a non-transitory computer readable storage medium accessible to the controller of the external device, with processor control instructions, etc., executed by one or more processor(s). Such a program configures the controller of the external device to execute the portion of the algorithm 4300.

[0145] In such a form, therapy parameters generated by the external device via the therapy engine module 4320 (which in such a form are part of the algorithm 4300 executed by the external device) may be communicated to the central controller 4230 for transmission to the therapy control module 4330.

[0146] Pre-processing module A pre-processing module 4310 according to one form of the invention receives as input a signal from a transducer 4270, e.g., a flow sensor 4274 or a pressure sensor 4272, and performs one or more process steps to calculate one or more output values ​​that are used as input to another module, e.g., a therapy engine module 4320.

[0147] In one form of the invention, the output values ​​are the interface pressure Pm, the ventilation flow Qv, the respiratory flow Qr, and the leak flow Q L Includes.

[0148] In various aspects of the invention, the pre-processing module 4310 includes one or more of the following algorithms: an interface pressure estimation algorithm 4312 , a ventilation flow estimation algorithm 4314 , a leak flow estimation algorithm 4316 , and a respiratory flow estimation algorithm 4318 .

[0149] Interface Pressure Estimation In one form of the invention, the interface pressure estimation algorithm 4312 receives as input a signal from a pressure sensor 4272 indicative of the pressure in the pneumatic path near the pneumatic block outlet (device pressure Pd) and a signal from a flow sensor 4274 representing the flow rate of the airflow leaving the RPT device 4000 (device flow Qd). The device flow Qd can be used as the total flow Qt in the absence of supplemental gas 4180. The interface pressure algorithm 4312 estimates the pressure drop ΔP through the air circuit 4170. The dependence of the pressure drop ΔP on the total flow Qt can be modeled for a particular air circuit 4170 by a pressure drop characteristic ΔP(Q). The interface pressure estimation algorithm 4312 then provides the estimated pressure Pm as an output to the patient interface 3000. The pressure Pm in the patient interface 3000 can be estimated as the device pressure Pd minus the air circuit pressure drop ΔP.

[0150] Ventilation Flow Estimation In one form of the invention, a ventilation flow estimation algorithm 4314 receives as input the estimated pressure Pm at the patient interface 3000 from the interface pressure estimation algorithm 4312 and estimates the ventilation flow Qv of air from the ventilator 3400 at the patient interface 3000. The dependence of ventilation flow Qv on the interface pressure Pm for the particular ventilator 3400 in use may be modelled by a ventilation characteristic Qv(Pm).

[0151] In another form of the invention, the ventilation flow Qv is estimated based on one or more ratios between the pressures on either side of the valve's diaphragm 6060 (i.e., the pressure on the blower pressure side (Bp) and the pressure at the patient interface (Pp)), as described further below.

[0152] In one aspect of the invention, a leak flow estimation algorithm 4316 receives as input the total flow Qt and the ventilation flow Qv and calculates the leak flow Q LIn one form, the leak flow estimation algorithm calculates the leak flow Q by calculating the average value of the difference between the total flow Qt and the ventilation flow Qv over a period of time long enough to include several respiratory cycles (e.g., 10 s). L Estimate.

[0153] In one form, the leak flow estimation algorithm 4316 calculates the leak conductance to determine the leak flow Q L as a function of leak conductance and pressure Pm, taking as input the total flow Qt, ventilation flow Qv, and estimated pressure Pm at the patient interface 3000, and determining the leak flow Q L The leak conductance is calculated as the quotient of the low-pass filtered non-ventilation flow, which is equal to the difference between the total flow Qt and the ventilation 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 respiratory cycles, for example about 10 seconds. L can be estimated as a function of the product of the leak conductance and the pressure Pm.

[0154] Respiratory flow estimation In one form of the invention, the respiratory flow estimation algorithm 4318 calculates the total flow Qt, the ventilation flow Qv, and the leak flow Q L It takes as input the ventilation flow rate Qv and the leakage flow rate Q L The air respiratory flow Qr for the patient is estimated by subtracting Qt from the total flow Qt.

[0155] Therapy Engine Module In one form of the present invention, the therapy engine module 4320 receives as inputs one or more of the pressure Pm in the patient interface 3000 and the air breathing flow Qr to the patient and provides one or more therapy parameters as outputs.

[0156] In one form of the invention, the therapy parameter is the treatment pressure Pt.

[0157] In one form of the invention, the therapy parameters are one or more of the following: amplitude of pressure fluctuations, base pressure, and target ventilation.

[0158] In various embodiments, the therapy engine module 4320 includes one or more algorithms: a phase determination algorithm 4321, a waveform determination algorithm 4322, a ventilation determination algorithm 4323, an inspiratory flow limitation determination algorithm 4324, an apnea / hypopnea determination algorithm 4325, a snoring determination algorithm 4326, an airway patency determination algorithm 4327, a target ventilation determination algorithm 4328, and a therapy parameter determination algorithm 4329.

[0159] Phase determination In one form of the invention, the RPT device 4000 does not determine phase.

[0160] In one form of the invention, the phase determination algorithm 4321 receives as an input a signal indicative of respiratory flow Qr and provides as an output the phase Φ of the patient's 1000 current respiratory cycle.

[0161] In some forms, referred to as discrete phase determination, the phase output Φ is a discrete variable. One implementation of discrete phase determination provides a binary phase output Φ with a value of inspiration or expiration, e.g., a value represented by 0 and 0.5 revolutions, respectively, upon detecting the start of spontaneous inspiration and expiration, respectively. The "trigger" and "loop" RPT device 4000 can efficiently perform discrete phase determination because the trigger and loop points are the moments when the phase changes from expiration to inspiration and from inspiration to expiration, respectively. In one implementation of binary phase determination, the phase output Φ is determined to a discrete value of 0 (thus "triggers" the RPT device 4000) when the respiratory flow Qr has a value above a positive threshold, and is determined to a discrete value of 0.5 revolutions (thus "cycles" the RPT device 4000) when the respiratory flow Qr has a value more negative than a negative threshold. The inspiration time Ti and expiration time Te can be estimated as typical values ​​for many respiratory cycles of the time spent in phase Φ equal to 0 (representing inspiration) and 0.5 (representing expiration), respectively.

[0162] Another implementation of the discrete phase determination provides a ternary phase output Φ having one of the following values: inspiration, inspiration pause, expiration.

[0163] In another form, called continuous phase determination, the phase output Φ is a continuous variable, such as 0 to 1 revolution or 0 to 2π radian change. An RPT device 4000 with continuous phase determination may trigger and loop when the continuous phase is 0 revolutions and 0.5 revolutions, respectively. In one implementation of continuous phase determination, a fuzzy logic analysis of respiratory flow Qr is used to determine continuous values ​​of phase Φ. The continuous phase values ​​determined in this implementation are commonly referred to as "fuzzy phases." In one implementation of the fuzzy phase determination algorithm 4321, the following rules are applied to respiratory flow Qr: 1. If Qr is zero and increases rapidly, Φ is set to 0 rotations. 2. If Qr is large, positive, and stable, Φ is set to 0.25 revolutions. 3. If Qr is zero and decreasing rapidly, Φ is 0.5 revolutions. 4. If Qr is large and negative and stable, Φ is set to 0.75 revolutions. 5. If Qr is stable at zero and the 5-second low-pass filtered absolute value of Qr of respiratory flow is large, Φ is set to 0.9 revolutions. 6. When Qr is positive and the phase is expiration, Φ is set to 0 rotations. 7. If Qr is negative and the phase is intake, Φ is 0.5 revolutions. 8. 5-second low-pass filtered Qr absolute value of respiratory flow is large, Φ increases at a steady rate equal to the patient's respiratory rate and is low-pass filtered with a time constant of 20 seconds.

[0164] The output of each rule can be represented as a vector with a phase, which is the result of that rule, and a magnitude, which is a degree of ambiguity about the truth of that rule. Respiratory flow is ambiguity, such as "large", "stable", etc., as determined by appropriate membership functions. The results of the rules are represented as vectors and combined by some function, such as centroid. In this combination, the weights of the rules may be equal or different.

[0165] In another implementation of continuous phase determination, the phase Φ is first discretely estimated from the inspiration time Ti and expiration time Te based on the respiratory flow Qr as described above. The continuous phase Φ at any time can be half the percentage of the inspiration time Ti that has elapsed since the previous trigger time or half the percentage of the expiration time Te that has elapsed since the previous cycle time plus 0.5 revolutions (whichever is closer).

[0166] Waveform determination In one form of the invention, the therapy parameter determination algorithm 4329 provides a nearly constant therapy pressure throughout the patient's respiratory cycle.

[0167] In another aspect of the invention, the therapy control module 4330 controls the pressure generator 4140 to provide a therapy pressure Pt that varies as a function of the phase Φ of the patient's respiratory cycle according to a waveform template Π(Φ).

[0168] In one form of the invention, the waveform determination algorithm 4322 provides a waveform template Π(Φ) having values ​​in the range [0,1] on the domain of phase values ​​Φ for use by the therapy parameter determination algorithm 4329 .

[0169] In one form, applied to a discrete or continuous valued phase, the waveform template Π(Φ) is a square wave template with a value of 1 for phase values ​​less than 0.5 revolutions and a value of 0 for phase values ​​equal to or greater than 0.5 revolutions. In a form suitable for a continuous valued phase, the waveform template Π(Φ) has two smoothly curved sections, i.e., a phase value from 0 to 1 in the smoothly curved section (e.g., a rising cosine) rising up to 0.5 revolutions, and a smoothly curved section (e.g., exponentially for phase values ​​greater than 0.5 revolutions) decaying from 1 to 0. In a form suitable for a continuous valued phase, the waveform template Π(Φ) is based on a square wave, but with phase values ​​smoothly rising from 0 to a "rise time" less than 0.5 revolutions and smoothly falling from 1 to 0 during a "fall time" after 0.5 revolutions, the "fall time" being less than 0.5 revolutions.

[0170] In some forms of the invention, the waveform determination algorithm 4322 selects a waveform template Π(Φ) from a waveform template library according to the settings of the RPT device. Each waveform template Π(Φ) in the library may be provided as a look-up table of values ​​Π versus phase values ​​Φ. In other forms, the waveform determination algorithm 4322 uses a predefined functional form (which may be parameterized by one or more parameters (e.g., time constants of exponential curve portions)) to "dynamically" calculate the waveform template Π(Φ). The parameters of the functional form may be predefined or may be dependent on the current state of the patient 1000.

[0171] In some embodiments of the invention, applied to a discrete binary phase of inspiration (Φ=0 revolutions) or expiration (Φ=0.5 revolutions), the waveform determination algorithm 4322 calculates a waveform template Π "dynamic" as a function of the discrete phase Φ measured since the most recent trigger instant, and of time t. In one such embodiment, the waveform determination algorithm 4322 calculates the waveform template Π(Φ,t) in two parts (inspiration and expiration) as follows:

number

[0172] Here, Π i (t), and Π e (t) is the inhalation-exhalation portion of the waveform template Π(Φ,t). In one embodiment, the inhalation portion of the waveform template Π i (t) is the smooth rise from 0 to 1 parameterized by the rise time, which is the expiratory portion of the waveform template, Π e (t) is the smooth fall from 1 to 0 parameterized by the fall time.

[0173] 4.2.1.1.2 Ventilation determination In one form of the invention, the ventilation determination algorithm 4323 receives respiratory flow Qr as an input and determines a measurement indicative of the current patient ventilation, vent.

[0174] In some implementations, the ventilation determination algorithm 4323 determines a measure of ventilation that is an estimate of the actual patient ventilation, vent. One such implementation takes half the absolute value of the respiratory flow, Qr, or filters it through a low pass filter, such as a second order Bessel low pass filter with a corner frequency of 0.11 Hz.

[0175] In other implementation forms, the ventilation determination algorithm 4323 determines a measured value of ventilation vent that is substantially proportional to the actual patient ventilation. In such an implementation form, the peak respiratory flow rate Qpeak of the estimated cycle inhalation section is realized. Many other programs, including this program and the sampling of the respiratory flow rate Qr, generate measured values that are approximately proportional to the ventilation volume on the premise that the shape of the flow rate waveform does not change much (here, when the respiratory flow rate waveforms normalized in terms of time and amplitude are similar, the shapes of both respirations are considered similar). Simple examples include the median of the positive respiratory flow rate, the median of the absolute value of the respiratory flow rate, and the standard deviation of the flow rate. Any linear combination of any order statistics of the absolute value of the respiratory flow rate using a positive coefficient, and even some combinations using both positive and negative coefficients, are also approximately proportional to the ventilation volume. Another example is the average value of the respiratory flow rate at the K-th ratio (time) in the middle of the inhalation part, where 0 < K < 1. When the flow rate shape does not change, there are arbitrarily multiple measured values proportional to the completeness of ventilation.

[0176] 4.2.1.1.3 Inhalation Flow Restriction Determination In one form of the present invention, the central controller 4230 executes an inhalation flow restriction determination algorithm 4324 to determine the degree of inhalation flow restriction.

[0177] In one form, the inhalation flow restriction determination algorithm 4324 receives the respiratory flow rate signal Qr as an input and provides, as an output, a measure of the degree to which the inhalation part of the respiration indicates an inhalation flow restriction.

[0178] In one form of the invention, the inspiration portion of each breath is identified by a zero crossing detector. A number of equally spaced points (e.g. 65) representative of each time point are interpolated along the inhalation flow-time curve of each breath with an interpolator. The curve described by the points is then scaled with a scalar to be of uniform length (duration / cycle) and uniform area to eliminate the effects of changes in breathing rate and depth. The scaled breath is then compared in a comparator to a pre-stored template representing a normal open breath, similar to the inspiration portion of the breath shown in FIG. 6A. Breaths that deviate from this template at any time during inspiration by more than a pre-defined threshold (usually one scaling unit), e.g., breaths due to coughing, sighing, swallowing, burping (as determined by a test element), are rejected. For data that is not rejected, a running average of the first such scaled points for the first few inhalation events is calculated by the central controller 4230. For the second such point, this is repeated for the same inhalation event, and so on. Thus, for example, 65 scaled data points are generated by the central controller 4230 to represent a moving average of the first few inhalation events (e.g., 3 events). The moving average of the continuously updated (e.g., 65) point values ​​is hereinafter referred to as the "scaled flow rate" and identified as Qs(t). Alternatively, a single inhalation event may be used in place of the moving average.

[0179] From the scaled flow, two shape factors can be calculated that are relevant to determining partial obstruction.

[0180] The shape factor 1 is the ratio of the average of the middle (e.g. 32) scaled flow points to the average of the total (e.g. 65) scaled flow points. If this ratio exceeds 1, the breath is considered normal. If the ratio is less than or equal to 1, the breath is considered obstructed. A ratio of approximately 1.17 is used as the threshold between partial obstruction and unobstructed breaths, and is equivalent to a degree of obstruction that allows adequate oxygenation to be maintained in a typical patient.

[0181] Shape factor 2 is calculated as the root mean square deviation from unity scaling flow and is taken above a midpoint (e.g., 32). A root mean square deviation of about 0.2 units is considered normal. A root mean square deviation of zero is considered to be a completely flow-limited breath. The closer the root mean square deviation is to zero, the more flow-limited the breath is.

[0182] Shape factors 1 and 2 may be used alternatively or in combination. In other aspects of the invention, the number of sampling points, breath points, and midpoints may be different than those described above. Also, the thresholds may be different from those described.

[0183] Determining Apnea and Hypopnea In one form of the invention, the central controller 4230 executes an apnea / hypopnea decision algorithm 4325 to determine the presence of apnea and / or hypopnea.

[0184] In one form, the apnea / hypopnea decision algorithm 4325 receives as an input the respiratory flow signal Qr and provides as an output a flag indicating that an apnea or hypopnea has been detected.

[0185] In one form, apnea is detected when a function of respiratory flow Qr falls below a flow threshold for a predetermined period of time. The function can be a peak flow, a relative short-term average flow, or a flow intermediate the relative short-term average and peak flow, e.g., RMS flow. The flow threshold can be a relatively long-term measure of flow.

[0186] In one embodiment, hypopnea is detected when a function of respiratory flow Qr falls below a second flow threshold for a predetermined period of time. The function may determine a peak flow, a relative short-term average flow, or a flow intermediate the relative short-term average and peak flow, e.g., RMS flow. The second flow threshold may be a relatively long-term measure of flow. The second flow threshold is greater than the flow threshold for detecting apnea.

[0187] 4.2.1.1.4 Snoring determination In one form of the invention, the central controller 4230 executes one or more snore determination algorithms 4326 to determine the severity of snoring.

[0188] In one form, the snore determination algorithm 4326 receives as an input the respiratory flow signal Qr and provides as an output a measure of the degree of the presence of snoring.

[0189] The snore determination algorithm 4326 may include determining the strength of the flow signal in the range of 30-300 Hz. Additionally, the snore determination algorithm 4326 may include filtering the respiratory flow signal Qr to reduce background noise, for example the sound of airflow in the system from a blower.

[0190] 4.2.1.1.5 Airway patency determination In one form of the invention, the central controller 4230 executes one or more airway patency determination algorithms 4327 to determine the degree of airway patency.

[0191] In one form, the airway patency determination algorithm 4327 receives as input the respiratory flow signal Qr and determines the power of the signal in the frequency range of about 0.75 Hz and about 3 Hz. The appearance of peaks in this frequency range indicates an open airway. The absence of peaks is considered to indicate airway closure.

[0192] In one form, the frequency range in which the peak is sought is the frequency of a small forced oscillation at the treatment pressure Pt. In one embodiment, the forced oscillation has a frequency of 2 Hz and an amplitude of approximately 1 cmH2O.

[0193] In one form, the airway patency determination algorithm 4327 receives as input the respiratory flow signal Qr and determines the presence or absence of a cardiogenic signal, the absence of which may be indicative of airway obstruction.

[0194] Target ventilation determination In one form of the invention, the central controller 4230 executes one or more target ventilation determination algorithms 4328 which take as input the current ventilation measurement, vent, and determine a target value for the ventilation measurement, Vtgt.

[0195] In some forms of the invention, there is no target ventilation determination algorithm 4328 and the target value Vtgt is predetermined, for example by being hard-coded into the configuration of the RPT device 4000 or by being manually entered via the input device 4220.

[0196] In other forms of the invention, such as adaptive servo ventilation (ASV), the target ventilation determination algorithm 4328 calculates a target value Vtgt from a value Vtyp indicative of the patient's typical recent ventilation.

[0197] In some forms of adaptive servo ventilation, the target ventilation Vtgt is calculated as a high percentage of the typical recent ventilation Vtyp, but less than it. The high percentage in this form may be in the range of (80%, 100%) or (85%, 95%) or (87%, 92%).

[0198] In other forms of adaptive servo ventilation, the target ventilation, Vtgt, is calculated as a unit multiple slightly larger than the typical current ventilation, Vtyp.

[0199] Typical recent ventilation Vtyp is the value to which the distribution of current ventilation vent at multiple time instants in a given time scale tends to converge, i.e., a measure of the convergence tendency of current ventilation in the recent past. In an implementation of the target ventilation determination algorithm 4328, the recent history is on the order of minutes, but in any case should be longer than the time scale of a Cheyne-Stokes rising and falling cycle. The target ventilation determination algorithm 4328 can use any of a variety of known convergence tendency measures to determine the typical recent ventilation Vtyp from the measurement vent of current ventilation. One such measure is the output of a low pass filter on the current ventilation vent measurement, with a time constant equal to 100 seconds.

[0200] Determination of Therapy Parameters In some forms of the invention, the central controller 4230 executes one or more therapy parameter determination algorithms 4329 to determine one or more therapy parameters using values ​​returned by one or more other algorithms in the therapy engine module 4320.

[0201] In one form of the invention, the therapy parameter is the instantaneous therapy pressure Pt. In one implementation of this form, the therapy parameter determination algorithm 4329 determines the therapy pressure Pt using the formula:

number

[0202] where A is the amplitude, Π(Φ,t) is the current value of the phase Φ and the waveform template value (in the range 0 to 1) at time t, and P0 is the base pressure.

[0203] If the waveform determination algorithm 4322 provides the waveform template Π(Φ,t) as a lookup table of values ​​Φ indexed by the phase Φ, the therapy parameter determination algorithm 4329 applies equation (1) by locating the lookup table entry closest to the current value Φ of the phase returned by the phase determination algorithm 4321 or by interpolating between two entries that intersect the current value Φ of the phase.

[0204] Depending on the respiratory pressure therapy mode selected, the therapy parameter determination algorithm 4329 may set the amplitude A and base pressure P0 values ​​as follows:

[0205] Therapy Control Module A therapy control module 4330 according to one aspect of the present invention receives therapy parameters as input from a therapy parameter determination algorithm 4329 of the therapy engine module 4320 and controls the pressure generator 4140 to deliver airflow in accordance with the therapy parameters.

[0206] In one form of the invention, the therapy parameter is a therapy pressure Pt, and the therapy control module 4330 controls the pressure generator 4140 to deliver an airflow such that the interface pressure Pm at the patient interface 3000 is equal to the therapy pressure Pt.

[0207] Fault Condition Detection In one form of the invention, the central controller 4230 executes one or more methods 4340 for detecting a fault condition. The fault condition detected by the one or more methods 4340 may include at least one of the following: - Power off (power off or power off insufficient) Sensor failure detection -Inability to detect the presence of parts Operating parameters exceeding recommended ranges (e.g. pressure, flow, temperature, PaO2) The test alarm cannot generate a detectable alarm signal.

[0208] When a fault condition is detected, the corresponding algorithm 4340 indicates the presence of a fault by one or more of the following signals: Initiating audio, visual and / or dynamic (e.g. vibration) alarms Send messages to external devices Event logging

[0209] Air Circuit The air circuit 4170 according to one aspect of the present invention is a conduit or tube constructed and arranged to allow air flow to travel between two components (e.g., the RPT device 4000 and the patient interface 3000) when in use.

[0210] In particular, the air circuit 4170 may be in fluid communication with the outlet of the pneumatic block 4020 and the patient interface. The air circuit may be referred to as an air delivery tube. In some cases, there may be separate branches of the circuit for inhalation and exhalation. In other cases, a single branch is used.

[0211] In some forms, the air circuit 4170 may include one or more heating elements configured to heat the air in the air circuit, e.g., to maintain or increase the temperature of the air. The heating elements may take the form of a heated wire circuit and may include one or more transducers, e.g., temperature sensors. In one form, the heated wire circuit may be spirally wound around the axis of the air circuit 4170. The heating elements may be in communication with a controller, e.g., the central controller 4230. One example of an air circuit 4170 including a heated wire circuit is described in U.S. Patent Application No. 8,733,349, the entirety of which is incorporated herein by reference.

[0212] 4.2.2 Valve Assembly In one form of the invention, the air circuit 4170 (FIGS. 1A-1C) or patient interface 3000 (FIGS. 1A-1C) of a positive air pressure (PAP) therapy system may include a valve assembly 6000 (FIG. 8). The valve assembly 6000 may be configured as a combined one-way inhalation valve-exhalation valve assembly.

[0213] The valve assembly 6000 should typically be located as close as possible to the patient interface 3000. If the valve assembly 6000 is too far from the patient interface 3000, more dead space may result, potentially causing unacceptable levels of CO2 to build up in the mask space. Thus, the valve assembly 6000 may be located in or on the patient interface 3000, or in / on the air circuit 4170, but may be located near the patient interface 3000. The valve assembly 6000 may include a housing 6010 and a pressure actuated valve member 6020.

[0214] The valve assembly 6000 includes: Inlet 6030 (also called RPT port) and an outlet 6040 (which in some embodiments may be located on the patient interface and therefore also referred to as a patient interface port); A ventilation section 6050 (also called an ambient port).

[0215] In one form, the pressure actuated valve member 6020 has a dual function combining a one-way inhalation or inhalation valve capable of providing pressurized airflow to the patient's airway (only or primarily during inhalation) and an exhalation discharge valve that controls ventilation flow to ambient atmosphere (only or primarily during exhalation). This allows the combination valve to effectively control airflow from the RPT device 4000 to the patient side of the mask 3000 and airflow from the interior of the mask 3000 to ambient atmosphere. In particular, the combination valve 6000 may be constructed and arranged to operate in two primary states. i. In a first state, air passes between the RPT port 6030 and the patient interface port 6040, and the flow path to the surroundings (e.g., the ventilation section 6050) is closed; and ii. In a second state, the RPT port is closed (e.g., air flow to the RPT port 6030 is blocked), while air flows from the patient interface port 6040 to the ambient port 6050 and from there to the ambient port 6050.

[0216] In one form, the valve assembly 6000 includes a valve member such as a diaphragm 6060 made from a silicone material and having a substantially circular profile, as shown, for example, in Figures 9 and 10. In other examples, the diaphragm 6060 may have an elongated shape, such as an oval, elliptical, or stadium shaped profile, as shown, for example, in Figures 11 and 12. In some examples, the cross-sectional shape of the patient interface port 6040 (or at least the entrance to that port) may be substantially the same as the shape of the diaphragm 6060, e.g., in examples with a substantially circular diaphragm 6060, the entrance to the patient interface port 6040 may be substantially circular, and in examples with a substantially elliptical diaphragm 6060, the entrance to the patient interface port 6040 may be substantially elliptical.

[0217] 11 and 12, the periphery 6070 of the diaphragm 6060 includes a retention flange feature 6080 configured to position and retain the diaphragm 6060 within the housing 6010. At the center of the diaphragm 6060 is a one-way valve 6090 configured as a duckbill valve. Referring to FIG. 16, the valve 6090 allows air to pass in only one direction through the diaphragm 6060, from the RPT port 6030 to the patient interface port 6040.

[0218] With reference to FIG. 10, the diaphragm 6060 has a membrane portion 6100 between the retaining flange 6080 and the duckbill valve 6090. The retaining flange 6080 may be the only part of the diaphragm 6060 that is fixed to the assembly, allowing the membrane portion 6100 to move in response to pressure differences acting on either side. They may be formed as part, but the duckbill valve 6090 and the membrane portion 6100 may operate independently of each other. The duckbill valve 6090 controls the airflow from the RPT device 4000 (or blower, see inlet 6030 in FIG. 8) to the patient interface 3000 (or mask, see outlet 6040 in FIG. 8), and the membrane portion 6100 controls the airflow from the patient interface 3000 (or mask) through the ventilation section 6050. The diaphragm 6060 is a dynamic component and responds to any significant pressure changes, including the user's breathing.

[0219] Exemplary properties of the diaphragm 6060 include material preferences of silicone, Shore hardness of 30-60 Shore (A), and manufacturing process of LSR or CMSR.

[0220] 4.2.2.1 Duckbill valve In one form, the diaphragm 6060 has a duckbill valve 6090 in the center of the membrane portion 6100. The duckbill valve is a one-way valve that allows air to pass through the diaphragm 6060 in only one direction. The pressure difference on either side of the duckbill valve 6090 determines whether the valve is open or closed. The material, dimensions, and shape of the duckbill valve 6090 affect the flow rate through the membrane and the impedance.

[0221] 9-12 show an example of a duckbill valve 6090 in a closed configuration.

[0222] 13 and 24 show an example of a duckbill valve 6090 in an open configuration.

[0223] Valve Assembly 8, 14, and 15, the retention flange 6080 positions the diaphragm 6060 between the two housing portions 6012, 6014. The retention flange 6080 may also act as a seal between the upstream portion 6012 and the downstream portion 6014 of the housing 6010, for example, between the RPT device (or blower) and the mask air path, and between the RPT device and the ambient port. When integrated, the retention flange 6080 may be the only portion of the diaphragm 6060 that is fixed to the assembly, thereby allowing the membrane portion 6100 to move in response to upstream and downstream pressure differentials.

[0224] In one form, the present invention includes a pressure sensor 6110 (see FIG. 16) connected directly or indirectly (i.e., via a connection to a conduit 4170) to the patient interface 3000. A controller (e.g., therapy device controller 4240) monitors the pressure within the patient interface 3000 (as measured by the pressure sensor 6110) and controls the pressure generator 4140 to regulate the flow rate of the generated air supply.

[0225] The retention flange 6080 of the diaphragm 6060 may sit within a recess 6120 in one housing part (e.g., the first plastic component). This feature ensures that the diaphragm 6060 is precisely positioned within the housing 6010 and prevents unwanted lateral movement.

[0226] When assembled, the retention flange 6080 of the diaphragm 6060 can form an interference seal between the two housing portions 6012, 6014, as shown in FIG.

[0227] 15-17, an intermediate portion 6102 of the diaphragm membrane 6100 is slightly outboard and / or peripheral to the inner duckbill valve portion 6090 and effectively controls access (e.g., from the patient interface port 6040 to the vent) by interacting (e.g., substantially perpendicular to the upstream-downstream direction) with an annular rib 6130 (which may extend inwardly in the upstream direction). The contact between portion 6102 of the diaphragm membrane 6100 and the annular rib 6130 controls the exit flow path from the downstream (mask side) space of the housing to the surroundings.

[0228] 18 and 19, the gap between the diaphragm membrane 6100 and the rib 6130 (outlet flow path inlet) defines a portion of the flow path from the patient interface 3000 to the ventilation section 6050, thereby controlling the ventilation flow. In some configurations, the ventilation section 6050 includes one ventilation opening, and in other configurations includes multiple ventilation openings 6052. The ventilation opening(s) 6052 may have a larger and open combined area than that defined by the expected maximum clearance gap between the diaphragm membrane 6100 and the rib 6130. Thus, the outer ventilation openings 6052 may have less of an effect on the flow rate through the ventilation section 6050 than the size of the clearance gap. In examples, the flow rate through the ventilation section is always only a function of the size of the clearance gap between the diaphragm membrane 6100 and the rib 6130.

[0229] 4.2.2.2 Valve Assembly - Intake 16 and 17, in certain forms of the invention, the patient interface pressure drops during inspiration due to an increase in volume caused by the contraction (downward movement) of the user's diaphragm. The pressure sensor 6110 may record this change and signal the RPT device to provide more airflow to achieve a predetermined pressure and / or maintain a set pressure. The RPT device airflow increases the RPT device pressure (P1) in the valve assembly 6000. This pressure (P1) is higher than the patient interface pressure (P2) and causes the diaphragm membrane 6100 to move towards the patient interface port rib 6130 until the membrane resistance (caused by the membrane's elastic properties and defined by the membrane's structural configuration and the membrane's material elastic properties) is overcome and contacts the patient interface port rib 6130. This at least partially closes the exhalation valve and reduces or prevents flow through the valve vent to the ambient atmosphere. A particular membrane design and / or material may close the valve under a particular target (predetermined) pressure differential. If the membrane resistance is negligible, the valve is said to close when the upstream pressure becomes higher than the downstream pressure. As will be explained in more detail later, the pressure differential may open the duckbill valve 6090 to allow air flow to the patient interface 3000. This air flow increases the patient interface pressure (P2) until the desired therapeutic pressure is reached.

[0230] Holding the diaphragm membrane 6100 in this closed (or at least partially closed) position during inspiration reduces both the airflow through the ventilation section 6050 and the potential associated pressure drop. As a result, the RPT device does not have to work as hard to maintain the required mask pressure P2. This reduction in airflow / pressure loss during inspiration therefore improves the overall efficiency of the blower and the RPT device.

[0231] 4.2.2.2.1 Duckbill Valve - Intake As previously mentioned, during inspiration the RPT device pressure is higher than the patient interface pressure and the duckbill valve 6090 opens, allowing airflow to the patient interface 3000. This airflow increases the patient interface pressure until the desired CPAP pressure is reached.

[0232] The duckbill valve 6090 can open whenever the RPT device pressure (upstream of the valve) exceeds the patient interface pressure (downstream of the valve). In some cases, the valve can be configured to open only if the upstream pressure exceeds the downstream pressure by more than a predetermined amount, and in some cases the predetermined amount can be very close to zero, so that the duckbill valve 6090 can be configured to open again almost immediately if the RPT device pressure is higher than the patient interface pressure. If the duckbill valve is designed to open at a predetermined pressure difference, the predetermined pressure difference at which the valve opens can be related to the resistance force that must be overcome to separate the two lips 6150. This resistance force can be related to the mechanical design, dimensions, and manufacturing materials of the valve. Changing these can cause the valve to open at a particular target (predetermined) pressure difference. If these resistance forces are negligible, it can be said that the valve opens when the upstream pressure starts to get higher than the downstream pressure.

[0233] 4.2.2.3 Valve Assembly - Exhalation 18 and 19, in some forms of the invention, the volume caused by the user's diaphragm relaxing (moving up) during exhalation decreases, causing an increase in patient interface pressure. The pressure sensor 6110 may record this change and send a signal to the RPT device 4000 to reduce or stop the airflow. As a result, the patient interface pressure becomes higher than the RPT device pressure of the valve assembly 6000, and the diaphragm membrane 6100 is introduced into the airflow path away from the patient interface port rib 6130 and into the atmosphere (i.e., via the ventilation section 6050), as shown in particular in FIG. 19. Also, the duckbill valve 6090 closes, ensuring that no backflow is allowed back into the RPT device. The pressure in the patient interface 3000 decreases as the user's exhalation progresses, and the airflow is vented to the atmosphere. The pressure sensor 6110 monitors this pressure drop, and in some examples, the RPT device airflow remains blocked until the patient interface pressure drops below a predetermined pressure or set CPAP pressure.

[0234] In some examples, the RPT device 4000 provides some flow during the exhalation phase even when the patient interface pressure is higher than the predetermined pressure or set CPAP pressure. This flow may be at a relatively low rate and can help entrain stagnant CO2, thus improving CO2 washout from the patient interface 3000.

[0235] In some examples, the pressure difference required to move the valve membrane away from the patient interface port rib 6130 (e.g., to initiate ventilation) is close to zero, such that ventilation begins almost immediately when the patient interface pressure becomes higher than the RPT device pressure.

[0236] The ventilation openings 6052 themselves are typically sized to have little or no effect on the flow rate through the ventilation section 6050 as the ventilation flow rate is controlled by the clearance cap between the diaphragm membrane 6100 and the ribs 6130 (the total area of ​​the ventilation openings 6052 is sufficiently larger than the area of ​​the flow between the diaphragm membrane 6100 and the ribs 6130 so as to have little or no effect on the flow rate). The structure surrounding the ventilation openings 6052 is provided to protect the diaphragm 6060 and to protect it from foreign objects.

[0237] 4.2.2.3.1 Duckbill valve - Exhalation In certain forms of the invention, when the patient interface pressure is higher than the RPT device pressure, the duckbill valve 6090 is closed. Thus, in some instances, there is no user airflow reaching the RPT device during exhalation.

[0238] 20, the valve (i.e., duckbill valve 6090) may be configured to avoid a complete seal when closed in order to allow some RPT flow to reach the patient interface 3000 even during the exhalation phase. This flow may be at a relatively low rate and may aid in the entrainment of stagnant CO2, thus improving the flushing of CO2 from the patient interface 3000.

[0239] 4.2.2.4 Diaphragm membrane 10 and 17, in one form, the diaphragm 6060 has a membrane portion 6100 connected to the duckbill valve 6090. At or near the base of the duckbill valve 6090 there is a section that interferes with the patient interface port ribs 6130, for example a small flat section (also called a portion) 6102 of the membrane 6100. In one form, the membrane portion 6100 may move up or down in response to a pressure differential acting on both sides. Movement of the membrane towards or away from the ribs 6130 does not significantly affect the outer diameter or the shape or performance of the duckbill valve 6090.

[0240] In examples, the diaphragm 6060 may have a first wall 6140 that extends from the retention flange 6080 to the periphery of the membrane portion 6100. In examples having a circular diaphragm, the first wall 6140 may be substantially cylindrical or conical (sloping). In examples where the diaphragm is substantially elliptical, the first wall may be an elliptical cylinder.

[0241] In some examples, the first wall 6140 extends downstream from the retention flange 6080 such that the edge of the membrane portion 6100 extending from the first wall 6140 is offset downstream from either the retention flange 6080 or the inlet of the patient interface port (e.g., rib 6130). This does not necessarily have to be the case, and the membrane portion 6100 may be flush with or extend upstream from either the retention flange 6080 or the rib 6130.

[0242] Forming the diaphragm 6060 as shown increases the ability of the diaphragm 6060 to move in response to pressure changes. As shown in Figures 18-21, when the downstream pressure is higher than the upstream pressure, the first wall 6140 is pivoted about the retention flange 6080 to the position shown in 6140a (Figure 21) as the diaphragm 6060 moves away from the rib 6130. Such movement allows the diaphragm 6060 to move away from the patient interface port 6040 without requiring the diaphragm material to stretch, as would be the case if the diaphragm 6060 were substantially planar. Additionally, the base of the duckbill valve 6090 can close, or at least substantially decrease in width, during patient exhalation, thereby increasing the gap between the portion 6102 and the annular rib 6130 of the patient interface port, allowing increased air to flow to the vent 6050, thus reducing the effort required to exhale.

[0243] Another advantage of the illustrated structure may relate to the ability of the membrane to perform its two functions substantially independently. In particular, the separation of these two functions may be facilitated by the ability of the membrane to pivot partially about the retaining flange 6080 and / or portion 6102. This pivoting may allow the motion of the central portion of the duckbill shaped membrane to function substantially as a reverse valve for the airflow generated by the RPT device, substantially separate from the valve-like function of the outer, more peripheral portions of the membrane (6102, 6140).

[0244] In some examples, the first wall 6140 may be substantially the same thickness as the remainder of the diaphragm 6060 (excluding the retention flange 6080). In some examples, the diaphragm is configured to be as thin and light as possible. Alternatively, a portion of the membrane (e.g., 6140 and / or 6102) may be thinner than the remainder of the membrane, for example to improve potential separation between various portions of the membrane.

[0245] Valve Assembly - Breathing Cycle In a particular form of the invention, the diaphragm dynamically moves between inhalation and exhalation positions during the user's breathing cycle, driven by the pressure differential described in the paragraph above (see simplified respiratory curve diagram in FIG. 22). The valve assembly can be referred to as an exhalation actuated valve (EAV), since its function is to facilitate an airflow path to the ambient atmosphere. However, as mentioned above, another important part of the function of this assembly is to act as a one-way valve, allowing the airflow generated by the RPT device to reach the mask only (or mostly) during inhalation, and to be restricted or completely stopped during exhalation. Thus, the function of the assembly is always responsive to all phases of the breathing cycle, and is not limited to the exhalation phase, and the simplified exemplary diagram herein describes only / mainly extreme situations.

[0246] 4.2.2.5 Valve Assembly - Ventilation Flow As highlighted in the previous section of this specification, in certain forms of the invention, the valve assembly 6000 is only vented to the atmosphere during exhalation. Therefore, the ventilation flow curve may not follow the constant flow characteristic of conventional systems, but may follow the shape of an "on-off" curve. FIG. 23 shows an example of what the ventilation flow of the valve assembly 6000 may look like when compared to conventional systems. In such an example, most or all of the ventilation flow that may occur in the valve assembly 6000 system is powered by the user's effort. The flow path to the ventilation section is only open part of the time, reducing the overall loss of pressure / flow and the humidity loss that comes with the loss of flow. This reduces the overall demand on the blower and humidification system and improves electrical and blower efficiency compared to conventional CPAPs. Such improved efficiency allows for the use of smaller blowers and / or heater plates used in the humidifier. This is particularly beneficial for portable devices, especially those that operate using batteries.

[0247] Alternatively, the valve member 6020 may be configured to maintain a limited ventilation flow to the surrounding atmosphere during inspiration to maintain airflow circulation and safe CO2 levels.

[0248] For the valve assembly described above to be successfully implemented in a PAP system, there are certain requirements that must be met. According to some forms of the invention, the valve assembly 6000 closes access to the air circuit 4170 during exhalation. Without access to this internal volume of the air circuit, most or all of the exhaled airflow in this configuration must be exhausted through the valve assembly 6000 to atmosphere via the ventilation section 6050. To reduce the risk of pressure build-up (fluctuations) such as during exhalation, the ventilation section 6050 and ventilation openings 6052 of the valve assembly 6000 may need to be configured to allow a high flow rate to reduce the impedance of the airflow being exhausted to atmosphere.

[0249] For example, in the example of the invention shown in FIG. 19, during the exhalation phase, the flow path to the ventilation section 6050 is open. This is prompted by the exhalation pressure creating a gap between the membrane 6100 and the patient interface port rib 6130. This configuration is at least partially self-regulating as the gap can increase with increasing patient interface pressure, thereby gradually decreasing the flow impedance with increasing patient interface pressure. The size of the opening created by the membrane away from the rib 6130 is limited by a resistance force created by the elastic properties of the membrane, which resists the membrane's deflection away from the equilibrium state. Due to this regulation mechanism, the patient faces a drop in impedance during exhalation, and generally the greater the respiratory effort, the greater the drop in respiratory impedance. This makes it easier for the patient to exhale due to the opening of the ventilation flow path during exhalation, reducing pressure fluctuations (changes in patient interface pressure) during exhalation. In contrast, prior art patient interfaces with fixed ventilation areas can experience increased patient interface pressure during peak expiratory flow rates. Thus, this valve assembly can provide some substantial benefits when used with a PAP system. This is even more important considering the fact that users of such systems are often asleep and sudden pressure fluctuations may wake them up. A self-regulating system that reduces these pressure fluctuations by dynamically adjusting the size of the airflow path to the ambient atmosphere may help to avoid such episodes, which may increase user comfort and improve compliance with prescribed treatment.

[0250] In examples of the present invention, the patient interface 3000 (and / or valve) may be configured to allow a small ventilation flow (e.g., 0.1 L / s) during the inspiration phase, such as when the membrane is closed against the patient interface port rib 6130. This ventilation flow may be much smaller (e.g., about 10%) than the ventilation flow of prior art patient interfaces. This smaller ventilation flow may aid in the removal of CO2 while reducing power requirements to the blower and humidification system.

[0251] The structure and function of the valve is best illustrated in Figure 24, which also shows a simulation of the flow through a duckbill valve 6090 according to one form of the present invention. As can be seen in Figure 24, the ends 6160 of the two lips 6150 are connected to each other, and when the duckbill valve 6090 is open, the lips 6150 are not parallel, but rather form an opening 6170 in the shape of a fish pouch or lens.

[0252] 34 and 35, in some examples, the downstream housing portion 6014 may include one or more flow guiding portions 6180 that direct the exhalation flow from an inlet of the patient interface port 6040 (e.g., a rib 6130) to one or more corresponding peripheral ports / outlets 6050 during exhalation.

[0253] In some examples, there are multiple flow guide portions, and each flow guide portion includes a ramp portion 6190. In some examples, each ramp portion 6190 slopes slightly downward from the level of the edge 6130 such that airflow (during exhalation) is directed away from the mask port 6040 and toward the lower edge of the opening of the respective port 6050.

[0254] The flow guide portion 6180 may include sidewall portions 6200 on either side of the ramp portion 6190 to form a channel. In some examples, the upper edge 6210 of each sidewall portion 6200 may be horizontal or may slope horizontally from the level of the upper surface of the respective peripheral port 6050 to approximately the level of the rib 6130. The slope may be upward or downward. This arrangement is such that the sidewall portions 6200 do not interfere with the closure of the diaphragm 6060.

[0255] The flow guiding portion 6180 may help reduce flow turbulence (e.g., during exhalation) into the peripheral port 6050 by avoiding, or at least reducing the magnitude of, a sudden expansion of exhaled gases. Conversely, gas may propagate near the flow guiding surfaces.

[0256] In contrast, the downstream housing portion 6014 of the example shown in Figures 17-21 and 1 is disposed as follows: During exhalation, the airflow passing through the relatively narrow gap between the rib 6130 and the membrane portion 6102 may have to flow around sharp edges, suddenly change direction, and suddenly expand into the relatively large chamber 6220 (see Figure 36), and therefore may become turbulent.

[0257] Turbulence between the ribs 6130 and the peripheral ports 6050 can cause the membrane 6100 to vibrate, resulting in variations in the clearance between the ribs 6130 and the membrane section 6102, which in turn can cause variations in the vent flow. The vibrations can also be accompanied by an audible effect and can be unpleasant for the user. In contrast, the smoother ventilation flow produced by the arrangement with the flow guides 6180 of the embodiment of Figures 34 and 35 can be smoother, more stable and quieter. This flow is also closer to laminar flow, and laminar flow can be more accurately estimated based on the models and methods described herein.

[0258] 4.2.4 Noise reduction As the valve configuration is constantly and dynamically re-adjusted during the user's breathing cycle, the membrane can produce the flapping (or banging) noise typical of membrane valves, which can be unpleasant for the user and can disrupt their sleep during prescribed therapy.

[0259] In some instances, such noises can be reduced if the valve member 6020 is made of a relatively soft material, such as silicone or silicone rubber. Alternative soft materials can be used. Thus, by making the valve member 6020 out of silicone or silicone rubber, among other benefits, noises generated when the duckbill portion 6090 of the valve closes can be reduced. If the valve member 6020 were made out of other materials, particularly harder materials, a flapping (thumping) noise could be generated whenever the two opposing portions of the duckbill valve 6090 come into contact when the valve is closed, and whenever the portion 6102 comes into contact with the rib 6130.

[0260] The use of an elongated valve member 6020, such as an oval or stadium shaped valve (e.g., as shown in Figures 11 and 12) and a correspondingly shaped duckbill valve 6090, can also reduce noise generation compared to a circular or disk shaped valve. The elongated shape creates a larger overall opening when the two opposing lips 6150 of the duckbill valve 6090 move only a small distance across the length of the "duckbill". This reduces the distance the part 6150 must travel to create a given flow area when moving between open and closed positions. The maximum speed the part 6150 can achieve during its movement is also reduced. The reduced distance and speed can reduce the overall noise associated with the movement.

[0261] 11 and 12, in some examples, the base of the duckbill valve 6090 may have a length dimension L substantially parallel to the major axis of the diaphragm 6060 and a width dimension W substantially parallel to the minor axis of the diaphragm 6090 (the minor and major axes are perpendicular to one another). The length L may be greater than the width W to achieve the noise reduction benefits of increasing the length of the valve. In some examples, the ratio of L:W may be at least 1.5:1, such as about 2:1. In some examples, the ratio of the length of the major axis of the diaphragm 6090 to the length of the minor axis of the diaphragm 6090 is at least 4:3.

[0262] Measures taken to reduce diaphragm resonance (eg, as described below) may also reduce noise.

[0263] 4.2.5 Resonance reduction In some examples, as discussed in the previous paragraph, cyclical changes in pressure differential across the valve membrane 6100 (including, for example, changes due to adjustments in blower flow rate) can cause the valve membrane 6100 to vibrate at a primary resonant frequency associated with its structure and configuration, which can generate undesirable noise and affect the operation of the diaphragm.

[0264] To reduce the likelihood of resonance occurring during normal operation of the device, the valve member 6020 may be formed with one or more portions or regions having a different thickness than one or more other portions or regions. This allows each portion to have a different resonant frequency, and there is not a single dominant resonant frequency for the entire membrane. In examples, arrangements are targeted where a resonant response may only occur under conditions outside the expected operating conditions of the system (e.g., in a system intended for use with a maximum pressure of up to 20 cmH2O, the system may be configured such that a resonant response is expected when the system is used at a pressure of 24 cmH2O).

[0265] In some cases, the change in resonant response can be altered by changing the shape or structure of the membrane 6100 (e.g. areas of different thickness) to an arrangement that has no axis of symmetry, only a single axis of symmetry, or no more than two axes of symmetry. Any of the above configurations can change the resonant behavior of the membrane and reduce the overall noise associated with the membrane resonance.

[0266] In one example, the membrane 6100 may include one or more areas or sections characterized by one or more different material properties or characteristics. One example may be a variable (e.g., reduced) thickness that can accelerate and decelerate (and thus open and close) faster than other area(s) of the membrane. Instead of providing a two-dimensional (e.g., relatively wide) area of ​​reduced thickness as a means of varying the resonant response of the membrane 6100, the membrane 6100 may have one or more physical features (e.g., one or more substantially one-dimensional lines of reduced thickness, also referred to as grooves and / or cuts). Such different areas of different thickness or one or more grooves may define one or more portions of the membrane that are at least partially independently movable relative to other portions. Some of these portions may open and close more easily than other portions or may participate earlier or later in the opening and closing of the flap compared to other portions. This may also mean that one or more of these parts will resonate at different times or at different frequencies compared to the other parts, resulting in a more complex resonant behavior where the membrane 6100 resonates at a single frequency rather than a single body. This may reduce the overall noise associated with the resonant motion of the membrane. In another arrangement, instead of grooves, one or more reinforcing ribs may be introduced on the surface of the membrane or within the body of the membrane. The ribs may also split the membrane, creating an asymmetric structure and altering the resonant behavior of the membrane, potentially reducing the overall noise.

[0267] By way of illustration, Figure 25 shows an example of an alternative form of valve member that does not include a duckbill valve, but has exemplary portions of different thickness, in this case showing an area 6490 that is reduced in thickness, but can also be increased, compared to the main body of the membrane 6100. Although not shown in Figure 25, combinations of two or more different thicknesses are also possible, for example one or more areas of reduced thickness and one or more areas of increased thickness. Similarly, areas of different thickness may be introduced in conjunction with a duckbill arrangement.

[0268] 37, in one example, the resonant response of a peripheral portion of the diaphragm 6060 (e.g., membrane 6100) can be altered by adding one or more thickened portions 6500. In the example shown, the thickened portions 6500 are in the form of a generally C-shaped thickened portion 6510 disposed near the periphery of the duckbill valve 6090.

[0269] 38, in another example, where the desired response and resulting vibrations are to be achieved, the duckbill valve 6090 may have two opposing lips 6150 with areas of increased thickness. In the example shown, the areas of increased thickness are provided as thin lines of material 6520 extending from the base of each lip, for example, to the end of the respective lip 6150. As in the example shown in FIG. 37, the increased thickness 6510, 6520 may be integrally formed with the remainder of the valve member 6020 or may comprise separately formed components connected to the valve member 6020. In addition to affecting the mass of the component to which it is attached, areas of increased or decreased thickness may change the stiffness of the component or cause an asymmetric response to an otherwise symmetrical part.

[0270] FIG. 38 shows an example in which a thickened portion 6510 on the membrane 6100 is combined with a thickened portion 6520 on the lip 6150 of the duckbill valve 6090, however, in other examples, depending on the target resonance and location of vibration, the duckbill valve 6090 may have a thickened portion and the membrane 6100 may not be thickened.

[0271] Figure 39 shows another example of a technique having the C-shaped thickened portions 6510 shown in Figure 37 and linear thickened portions 6530 that extend radially across the membrane 6100. In the example shown, there are four radially extending thickened portions 6530, although in other examples a greater or lesser number may be provided. In other examples, the C-shaped portions 6510 may be omitted.

[0272] 40 shows another example having a thickened portion 6540 on the side of the duckbill valve 6020. In this example, the lip 6150 itself does not have a thickened portion 6540. The thickness of the thickened portion 6540 may be twice the thickness of the lip 6150.

[0273] Each of the above thickened portions may be integrally formed with the remainder of the valve member 6020, or may comprise a separately formed component that is connected (removably or not) to the valve member 6020. The separately formed components may be formed of the same material as the membrane 6100 or duckbill valve 6090, or may be formed of a different material. If different materials are used, the density and / or stiffness of the material forming the individual elements may differ from the density and / or stiffness of the material forming the adjacent or underlying portions of the valve member 6020.

[0274] In examples, the difference in thickness between the thickened portions 6490, 6500-6540 relative to adjacent portions of the valve member 6020 may vary from a ratio of about 1.5:1 to greater ratios, such as a ratio of 4:1 or 8:1 or 10:1. For example, if the majority of the membrane 6100 is about 0.5 mm thick, the thickened portion 6500 may be about 2 mm thick. Similarly, if the majority of the membrane 6100 is about 4 mm thick, the thinned portion 6490 may be about 3 mm thick.

[0275] As mentioned above, in other examples, additional elements may be layered on top of the valve member 6020 to modify its resonant characteristics. Such elements may not be connected to the valve member 6020 along its entire length. In one example, such elements may include a frame that is only secured to a respective portion of the valve member 6020 (the membrane 6100 or respective lip 6150) at the periphery of the valve member 6020, or not secured at all, but is mounted such that at least some movement of the valve member 6020 interferes with the frame.

[0276] In other examples, the valve member 6020 may have portions made of materials having different material properties. For example, portions of the valve member 6020 may have a different density and / or stiffness compared to other portions of the valve member 6020. In some examples, different portions may be made of different materials. In examples, the diaphragm 6060 may have multiple portions with different material properties.

[0277] Providing a variation in thickness at various portions of the membrane 6100 is a relatively low-cost process that helps improve the resonant response of the membrane. Using materials with different properties at various portions of the membrane or connecting / attaching additional components to such various portions can increase costs and manufacturing difficulties. However, these methods may still be applicable in some circumstances. For example, adding a C-shaped insert 6510 may be a preferred option for mitigating the resonant response of an existing membrane, such as the membrane 6100 (FIG. 37), since it can be relatively easily retrofitted into the membrane's bellows channel. Although various resonance reduction methods have been described above with reference to the example of a stadium shaped valve member 6020, the same methods may be applied to valve members of other shapes, such as circular valve members. Similarly, while various lines and areas have been described as examples of areas having different thicknesses and / or stiffness, other shapes and configurations may also be used.

[0278] 4.3 Ventilation flow estimation As mentioned above, in some examples, the RPT device 4000 may include an apnea detection algorithm.

[0279] To detect apnea, the RPT device 4000 must be able to measure or estimate the patient's respiratory flow during inspiration and expiration.

[0280] It may be difficult or impossible to directly measure the patient's respiratory flow. Therefore, (as in most prior art systems) the system measures the flow rate (Q B ) measurements can be relied upon to derive patient flow.

[0281] The flow rate delivered to the patient (Q p ) is estimated by using the patient flow (Q p In order to calculate the patient flow, ventilation (intentional leak Qv) and unintentional leak (Q L ) losses must be taken into account.

[0282] In prior art systems having a fixed ventilation area, the ventilation flow Qv is relatively easy to estimate based on the pressure in the patient interface 3000 and may be accurately estimated from the pressure at the outlet of the blower 4142. However, such prior art algorithms may not be able to accurately estimate the ventilation flow Qv from the valve assembly 6000 of the present invention due to the ability of the valve 6000 to dynamically change the ventilation flow opening in response to the pressure differential across the diaphragm 6060. This pressure differential is caused in part by the patient's breathing.

[0283] Applicant has discovered that in one or more examples of the present invention, ventilation flow Qv can be accurately estimated within a useful pressure range based on one or more ratios between the pressures on either side of the membrane (i.e., the blower pressure (Bp) and the patient interface pressure (Pp)).

[0284] 4.3.1.1 Methods for characterizing ventilation flows In order to estimate the ventilation flow Qv, the flow into the ventilation section needs to be mathematically modeled.

[0285] FIG. 27 shows an example of a system including an EAV, such as the EAV described with respect to FIGS. 8-24, having a downstream housing with the structure shown in FIGS.

[0286] Attempts to characterize the valve assembly 6000 of FIG. 27 statically (i.e., at various constant pressure / flow operating points) showed that the EAV exhibited some hysteresis. It was therefore decided to pursue dynamic data collection and analysis using various simulated breathing patterns at various therapeutic pressures. Various parameters associated with the valve assembly 6000 system are measured / estimated during one or more simulated dynamic breathing cycles. The measured / estimated parameters include at least blower pressure (Bp), patient interface pressure (Pp) and ventilation flow (Qv). The purpose of performing characterization during a breathing cycle is to capture the characteristics of the valve when exposed to various conditions. Thus, the simulated breathing cycle parameters are selected to provide a wide range of breathing rates, peak expiratory flows, and tidal volumes. The various selected simulated breathing characteristics facilitate analysis of the valve operation with respect to at least one of the following: a) one or more flow rates, b) one or more flow accelerations and / or decelerations, c) one or more peak expiratory flows, d) one or more tidal volumes, etc.

[0287] Repeat the test at several different mask pressures, e.g., 4cmH2O, 6cmH2O, and 8cmH2O.

[0288] Applicant has discovered that in all of the above cases, ventilation flow Qv can be reliably characterized as a function of the pressure ratio (e.g., Bp / Pp) between the pressures on either side of the membrane. Plot ventilation flow versus pressure ratio (Bp / Pp) for each treatment pressure. To better characterize, divide each plot into multiple regions or zones (e.g., 3 zones) based on trends in the data across the graph. In one example (see FIG. 28), Zone 1 is where Bp / Pp is less than 1.2, Zone 2 is where Bp / Pp is between 1.2 and 1.5, and Zone 3 is where Bp / Pp is greater than 1.5.

[0289] Next, using standard numerical techniques, a best fit curve equation for each zone is derived. Applicant has discovered that equations of different orders may be preferred for one or more different regions. For each zone, increasingly higher order equations are tried until the fit to the data stops improving.

[0290] In one aspect of the invention, the data in Zone 1 was found to best fit a third order polynomial for the Bp / Pp ratio. The data in Zone 2 was found to best fit a second order polynomial. The data in Zone 3 was found to best fit a linear equation. Thus, in one form of technology featuring the particular configuration of valves described herein (see FIG. 27), the pneumatic circuit and patient interface used, mask ventilation flow can be estimated using the following equation: Zone 1: Ventilation flow = a*(Bp / Pp)^3+b*(Bp / Pp)^2+c*(Bp / Pp)+d Zone 2: Ventilation flow = a*(Bp / Pp)^2+b*(Bp / Pp)+c Zone 3: Ventilation flow = a*(Bp / Pp)

[0291] It has also been discovered that the boundaries defining each zone can vary depending on the treatment pressure.

[0292] Linear interpolation is used to determine the appropriate polynomial coefficients and boundaries of the therapeutic pressure zones rather than the zones tested.

[0293] For one type of technology, Tables 2 and 3 below show the fitted equation coefficients and zone boundaries for two measured treatment pressures (4cmH2O and 6cmH2O), and the interpolated equation coefficients and zone boundaries for various treatment pressures between the two pressures (4cmH2O and 6cmH2O).

[0294] Tables 2 and 3 - Polynomial coefficients and zone boundaries [Table 2] [Table 3]

[0295] The derived equations, coefficients, and zone boundaries may depend on the mask spacing and configuration, and conduit spacing and configuration, as well as the overall configuration of the particular membrane and valve system. However, when they are derived for a particular combination of mask, conduit, and valve system, they may be able to cover a wide range of pressures and flows. The coefficients may also be pre-calculated and included in tables similar to Tables 2 and 3 above. Thus, the processor may reference the tabulated values ​​during operation of the RPT device rather than constantly calculating these coefficients. This greatly improves computational efficiency and reduces requirements on the processor.

[0296] An overview of the method for characterizing the ventilation flow is shown in FIG. 41 and includes the following steps: a. Perform at least one simulated breathing cycle using the respiratory treatment system (step 8000). b. Measure the flow through the valve ventilator, the pressure upstream of the valve, and the pressure downstream of the valve during at least one simulated breathing cycle (step 8010). c. Plot ventilation flow versus the ratio of pressures on either side of the diaphragm (step 8020). d. Identifying whether there are boundary points that divide the plotted data into one or more contiguous zones based on trends in the data (step 8030). e. Derive an equation for a best fit curve for the data of each identified zone (step 8040). f. Derive at least coefficients and constants from the fit equation that characterize the respective functions between pressure ratio and ventilation flow for each zone, at least at the first therapeutic pressure (step 8050).

[0297] The following optional steps are also shown: Repeat steps a) to e) for at least one second treatment pressure to derive coefficients and constants from each fitting equation characterizing the respective functions for each zone at the at least one second treatment pressure (step 8060). · Interpolating the derived coefficients and constants to derive coefficients and constants for treatment pressures other than at least the first and second treatment pressures (step 8070). · Calculate the respective ventilation flows for one or more respective therapy pressures for a given ratio of pressures upstream and downstream of the valve using the derived and / or interpolated coefficients and constants (step 8080).

[0298] The above method for calculating the ventilation flow Qv and the blower flow Q B and unexpected leakage current Q L Using existing methods of measuring and / or calculating Qp, the patient flow Qp can be calculated using the equation of FIG.

[0299] Figures 29, 30 and 31 show experimentally measured (solid lines) and estimated (dashed lines) flows for dynamically varying patient flow Qp at three different treatment pressures: 6 cmH2O (Figure 29), 8 cmH2O (Figure 30) and 12 cmH2O (Figure 31). These figures demonstrate that the above method can accurately estimate patient flow. The reference to dynamically varying flow rates is intended to illustrate the fact that the graphs do not use constant pressure and / or flow rates, but rather reflect a dynamic system that covers the range of pressures and flows typically associated with a patient's respiratory cycle during use of an RPT device.

[0300] The application of the above valve assembly 6000 to a PAP device provides the unique advantages of improved ease of use, efficiency and performance to the PAP system. The increased efficiency may allow the design of a more portable and energy and space efficient system. The self-regulating nature of at least some of the valve's functions is also useful in systems that operate on a closed control loop that maintains the pressure at the user's airway at a target pressure or within a target pressure range. However, due to the different structure and function of the valve assembly 6000, known methods of characterizing the system may no longer be appropriate or even applicable. The ability of the valve assembly to reliably derive the ventilation flow allows the user flow to be calculated and therefore all relevant therapeutic functions such as triggering, cycling, auto-setting algorithms, flow limitation detection, etc. This may facilitate the practical implementation of PAP systems using such dual function valve assemblies and allow the development of new and improved systems, including small portable systems.

[0301] It should be noted that several obvious alternatives are within the scope of the above disclosure. For example, while the above describes plotting ventilation flow versus pressure ratio (Bp / Pp) for multiple treatment pressures, it could also be plotted versus the inverse pressure ratio (Pp / Bp). Such plots would allow for subsequent analysis and derivation of equations / parameters similar to those described.

[0302] 4.3.2 Humidifier 4.3.3 Humidifier Overview In one form of the invention, a humidifier 5000 (e.g., as shown in Figure 5A) is provided for modifying the absolute humidity of air or gas for delivery to a patient relative to the ambient air. Typically, the humidifier 5000 is used to increase the absolute humidity and raise the temperature of the air stream (relative to the ambient air) before it is delivered to the patient's airways.

[0303] The humidifier 5000 may comprise a dock 5130, a humidifier reservoir 5110, a humidifier inlet 5002 for receiving an airflow, and a humidifier outlet 5004 for delivering a humidified airflow. In some forms, as shown in Figures 5A and 5B, the inlet and outlet of the humidifier reservoir 5110 may be the humidifier inlet 5002 and the humidifier outlet 5004, respectively. The humidifier 5000 may further comprise a humidifier base 5006. The humidifier 5000 may further comprise a humidifier base 5006 adapted to house the humidifier reservoir 5110 and may comprise a heating element 5240.

[0304] In some examples, the humidifier further comprises a conductive portion 5120 , a lock lever 5135 , and a water level indicator 5150 .

[0305] In one form of the invention, the anti-spillback valve 4160 is located between the humidifier 5000 and the pneumatic block 4020.

[0306] Another form of humidifier according to the present invention is a passive or condensing humidifier, sometimes referred to as a heat and moisture exchanger (HMX) 7000. One form of a passive humidifier is shown in Figures 32 and 33. The passive humidifier 7000 may include a moisture absorbent material 7010 held in place between two frame members 7020. In use, the passive humidifier 7000 may be positioned in the air circuit 4170 between the patient interface 3000 and the valve assembly 6000 to collect moisture exhaled by the patient.

[0307] In the present examples, one of the consequences of reducing the ventilation flow during the inhalation phase, compared to some prior art patient interfaces, is to reduce the water / humidity loss from the system. In these prior art systems, as the ventilation assembly ventilates to the atmosphere during inhalation, previously exhaled air leaves the system, potentially resulting in a significant amount of airflow (and therefore pressure) and humidity being lost to the atmosphere. In contrast, the ventilation arrangement described above is closed to the environment during inhalation, and most of the water / humidity contained in the exhaled air and generated by the humidifier 5000 is delivered to the patient's lungs. This can reduce the amount of humidity that must be provided by a humidifier such as shown in Figures 5A and 5B, and therefore the amount of water and energy consumed by such a humidifier. The reduced ventilation flow during inhalation can also help a passive humidifier 7000, such as shown in Figures 32 and 33, to provide sufficient humidity to the patient, even in the absence of additional moisture from a humidifier such as shown in Figures 5A or 5B. 4.4 Respiratory waveform

[0308] FIG. 6 shows a model of a typical breathing waveform for a sleeping human. The horizontal axis is time and the vertical axis is respiratory flow. Although parameter values ​​may vary, a typical breath may have approximate values ​​of tidal volume Vt 0.5 L, inspiration time Ti 1.6 seconds, peak inspiratory flow Qpeak 0.4 L / sec, expiration time Te 2.4 seconds, and peak expiratory flow Qpeak-0.5 L / sec. The total time of the breath Ttot is about 4 seconds. Typically, a person breathes at a rate of about 15 breaths per minute (BPM) with a vent of about 7.5 L / min. A typical duty cycle, Ti to Ttot ratio, is about 40%.

[0309] 4.5 Respiratory Therapy Mode A variety of respiratory therapy modes may be implemented by the disclosed respiratory therapy system.

[0310] CPAP therapy In some implementations of respiratory pressure therapy, the central controller 4230 sets the treatment pressure Pt according to the treatment pressure equation (1) as part of the therapy parameter determination algorithm 4329. In one such implementation, the amplitude A is zero as well, and therefore the treatment pressure Pt (representing the target value that the interface pressure Pm should achieve at this time) is the same as the base pressure P0 throughout the respiratory cycle. This implementation is often classified under the heading of CPAP therapy. In such an implementation, the therapy engine module 4320 does not need to determine the phase Φ or the waveform template Π(Φ).

[0311] In CPAP therapy, the base pressure P0 may be a hard-coded constant value or may be a constant value manually entered into the RPT device 4000. Alternatively, the central controller 4230 may iteratively calculate the base pressure P0 as a function of indicators or measurements of sleep disordered breathing, such as one or more of flow limitation, apnea, hypopnea, patency, and snoring, returned by corresponding algorithms in the therapy engine module 4320. This alternative therapy may be referred to as APAP therapy.

[0312] FIG. 4E is a flow chart illustrating a method 4500 executed by the central controller 4230 to continuously calculate the base pressure P0 as part of the APAP therapy implementation of the therapy parameter determination algorithm 4329 when the pressure support A is also zero.

[0313] The method 4500 begins at step 4520 where the central controller 4230 compares the measured presence or absence of apnea / hypopnea to a first threshold to determine whether the measured presence or absence of apnea / hypopnea exceeds the first threshold for a predetermined time period indicating that apnea / hypopnea is occurring. If so, the method 4500 proceeds to step 4540, otherwise the method 4500 proceeds to step 4530. In step 4540, the central controller 4230 compares the measured airway patency to a second threshold. If the measured airway patency exceeds the second threshold indicating a patent airway, the detected apnea / hypopnea is deemed to be central and the method 4500 proceeds to step 4560, otherwise the apnea / hypopnea is deemed to be obstructive and the method 4500 proceeds to step 4550.

[0314] In step 4530, the central controller 4230 compares the measured flow limitation to a third threshold value. If the measured flow limitation exceeds the third threshold value, indicating that the inspiratory flow is limited, the method 4500 proceeds to step 4550; otherwise, the method 4500 proceeds to step 4560.

[0315] In step 4550, the central controller 4230 increases the base pressure P0 by a predetermined pressure increment ΔP, provided that the resulting therapeutic pressure Pt does not exceed the maximum therapeutic pressure Pmax. In one implementation, the predetermined pressure increment ΔP and the maximum treatment pressure Pmax are 1 cmH2O and 25 cmH2O, respectively. In other implementations, the pressure increment ΔP can be as low as 0.1 cmH2O and as high as 3 cmH2O, or as low as 0.5 cmH2O and as high as 2 cmH2O. In other implementations, the maximum therapeutic pressure Pmax can be as low as 15 cmH2O and as high as 35 cmH2O, or as low as 20 cmH2O and as high as 30 cmH2O. The method 4500 then returns to step 4520.

[0316] In step 4560, the central controller 4230 decreases the base pressure P0 by a decrement, provided that the decreased base pressure P0 does not fall below the minimum therapeutic pressure Pmin. The method 4500 then returns to step 4520. In one implementation, the decrement is proportional to the value of P0-Pmin, so that the decrease of P0 to the minimum therapeutic pressure Pmin is exponential in the absence of a detected event. In one implementation, the proportionality constant is set such that the time constant τ of the exponential decrease of P0 is 60 minutes and the minimum therapeutic pressure Pmin is 4 cmH2O. 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. In other implementations, the minimum therapeutic pressure Pmin can be as low as 0 cmH2O and as high as 8 cmH2O, or as low as 2 cmH2O and as high as 6 cmH2O. Alternatively, the decrement of P0 can be predetermined such that the decrease of P0 to the minimum therapeutic pressure Pmin is linear in the absence of a detected event.

[0317] Bilevel Therapy In other implementations of this aspect of the invention, the value of the amplitude A in equation (1) may be positive. Such implementations are known as bilevel therapy because when the therapeutic pressure Pt is determined using equation (1) with a positive amplitude A, the therapy parameter determination algorithm 4329 oscillates the therapeutic pressure Pt between two values ​​or levels in synchronization with the spontaneous breathing efforts of the patient 1000. That is, based on the exemplary waveform template Π(Φ,t) described above, the therapy parameter determination algorithm 4329 increases the therapeutic pressure Pt to P0+A (referred to as IPAP) during inspiration at the start of inspiration and reduces the therapeutic pressure Pt to a base pressure P0 (referred to as EPAP).

[0318] In some forms of bilevel therapy, IPAP is the same therapeutic pressure of interest as the therapeutic pressure in CPAP therapy mode, and EPAP is IPAP minus amplitude A, which has a "small" value (a few cmH2O), also called expiratory pressure release (EPR). This form is sometimes called CPAP therapy with EPR, and is often more comfortable than direct CPAP therapy. In CPAP therapy with EPR, IPAP and / or EPAP may be constant values ​​hard-coded into the RPT device 4000 or may be constant values ​​manually entered. Alternatively, the therapy parameter determination algorithm 4329 may iteratively calculate IPAP and / or EPAP during CPAP with EPR. In this alternative, the therapy parameter determination algorithm 4329 iteratively calculates EPAP and / or IPAP as a function of the sleep disordered breathing indicators or measurements returned from each algorithm in the therapy engine module 4320. This is done similarly to the calculation of base pressure P0 in APAP therapy described above.

[0319] In another form of bilevel therapy, the amplitude A is large enough so that the RPT device 4000 completes some or all of the breathing effort of the patient 1000. In this form, called pressure support ventilation, the amplitude A is called pressure support or swing. In pressure support ventilation, IPAP is the base pressure P0 plus pressure support A, and EPAP is the base pressure P0.

[0320] In some forms of pressure support ventilation therapy, known as constant pressure support ventilation therapy, the pressure support A is fixed at a predetermined value (e.g., 10 cmH2O). The predetermined pressure support value is a setting by the RPT device 4000 and can be set, for example, by hard-coding during configuration of the RPT device 4000 or by manual entry via the input device 4220.

[0321] In another form of pressure-support ventilation therapy, broadly known as servo-ventilation, the therapy parameter determination algorithm 4329 takes as input certain currently measured or estimated parameters of the respiratory cycle (e.g., the current measurement of ventilation, vent) and a target value of that respiratory parameter (e.g., the target value of ventilation, Vtgt) and continuously adjusts the parameters of equation (1) to bring the current measurement of the respiratory parameter closer to the target value. In a form of servo-ventilation called adaptive servo-ventilation (ASV), which is used to treat CSR, the respiratory parameter is ventilation and the target ventilation value, Vtgt, is calculated by the target ventilation determination algorithm 4328 from a typical recent ventilation, Vtyp, as described above.

[0322] In some forms of servo ventilation, the therapy parameter determination algorithm 4329 applies a control method that iteratively calculates the pressure support A in order to move the current measured value of the respiratory parameter closer to the target value. One such control method is proportional-integral (PI) control. In one implementation of PI control applied to ASV mode, where the target ventilation Vtgt is set slightly smaller than a modern typical ventilation Vtyp, the pressure support A is iteratively calculated as follows:

number

[0323] where G is the gain of the PI control. A larger value of the gain G can result in positive feedback in the therapy engine module 4320. A smaller gain value G can result in residual untreated CSR or central sleep apnea. In some implementations, the gain G is fixed at a predetermined value (e.g., −0.4 cmH2O / (L / min) / sec). Alternatively, the gain G can be varied between therapy sessions (starting at a low value and increasing between sessions) until a value is reached that substantially eliminates CSR. Conventional means for retrospectively analyzing parameters of a therapy session to assess the severity of CSR during the therapy session can be used in such implementations. In other implementations, the gain G can vary depending on the difference between the current measured value of ventilation, vent, and the target ventilation, Vtgt.

[0324] Other servo ventilation control methods that can be applied by the therapy parameter determination algorithm 4329 include proportional (P), proportional-derivative (PD), and proportional-integral-derivative (PID).

[0325] The value of pressure support A calculated by equation (2) can be clipped within the range defined as [Amin, Amax]. In this implementation, by default, pressure support A sits at the minimum pressure support Amin until the current ventilation, vent, falls below the target ventilation, Vtgt, at which point A starts to increase, returning to Amin only when vent again exceeds Vtgt.

[0326] The pressure support limits Amin and Amax are settings of the RPT device 4000 and are set, for example, by hard-coded during configuration of the RPT device 4000 or by manual entry through the input device 4220.

[0327] In pressure support ventilation therapy mode, EPAP is the base pressure P0. Similar to the base pressure P0 in CPAP therapy, EPAP may be a constant value, defined or determined during titration. Such a constant EPAP may be set, for example, by hard-coding during configuration of the RPT device 4000 or by manual input via the input device 4220. This alternative therapy may be referred to as fixed EPAP pressure support ventilation therapy. Titration of the EPAP for a given patient may be performed by a clinician during a titration session with PSG for the purpose of preventing obstructive apnea, thereby maintaining airway access for pressure support ventilation therapy in a manner similar to titration of the base pressure P0 in constant CPAP therapy.

[0328] Alternatively, the therapy parameter determination algorithm 4329 may repeatedly calculate the base pressure P0 during pressure support ventilation therapy. In such an implementation, the therapy parameter determination algorithm 4329 repeatedly calculates EPAP as a function of one or more of the sleep disordered breathing indicators or measurements, such as flow limitation, apnea, hypopnea, patency, and snoring, returned by the corresponding algorithm in the therapy engine module 4320. Because the continuous calculation of EPAP is similar to a clinician manually adjusting the EPAP during titration of the EPAP, this process may also be referred to as auto-titration of EPAP, and the therapy mode is referred to as auto-titration EPAP pressure support ventilation therapy, or auto EPAP pressure support ventilation therapy.

[0329] 4.6 Glossary For purposes of this disclosure, in certain aspects of the invention, one or more of the following definitions may apply. In other aspects of the invention, alternative definitions may apply.

[0330] 4.6.1 Overview Air: In certain aspects of the invention, air may be taken to mean atmospheric air, while in other aspects of the invention air may be taken to mean some other combination of breathable gases, such as, for example, oxygen-enriched air.

[0331] Ambient: In certain aspects of the invention, the term ambient is taken to mean (i) external to the treatment system or patient, and (ii) immediately surrounding the treatment system or patient.

[0332] For example, the ambient humidity for a humidifier may be, for example, the humidity of the air adjacent to the humidifier, such as the humidity of the room in which the patient is sleeping. Such ambient humidity may be different from the humidity outside the room in which the patient is sleeping.

[0333] In another example, ambient pressure can be the pressure immediately surrounding the body or pressure outside the body.

[0334] In certain forms, ambient (e.g., acoustic) noise may be considered to be the background noise level within the room in which the patient is located, as opposed to, for example, noise generated by the RPT device or emanating from a mask or patient interface. Ambient noise may be generated from sources outside the room.

[0335] Automatic Positive Airway Pressure (APAP) Therapy: A CPAP therapy that can automatically adjust therapeutic pressure between minimum and maximum limits, for example, on a breath-by-breath basis, depending on the presence or absence of signs of an SDB event.

[0336] Continuous Positive Airway Pressure (CPAP) Therapy: Respiratory pressure therapy in which the therapeutic pressure is approximately constant throughout the patient's respiratory cycle. In some forms, the pressure at the entrance to the airways is slightly higher during exhalation and slightly lower during inhalation. In some forms, the pressure varies during different respiratory 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.

[0337] Flow Rate: The amount (or mass) of air delivered per unit time. Flow rate may refer to an instantaneous quantity. In some cases, a reference to flow rate is to a scalar quantity, i.e., a quantity that has only a magnitude. In other cases, a reference to flow rate is to a vector quantity, i.e., a quantity that has both a magnitude and a direction. Flow rate may be given the symbol Q. "Flow rate" may simply be written as "flow" or "airflow."

[0338] In the example of a patient breath, the flow rate may be nominally positive for the inhalation portion of the patient's breathing cycle, and therefore negative for the exhalation portion of the patient's breathing cycle. The device flow rate Qd is the flow rate of air leaving the RPT device. The total flow rate Qt is the flow rate of air that reaches the patient interface via the air circuit, plus any supplemental gas. The ventilation flow rate Qv is the flow rate of air leaving the ventilation section to allow for the pushing out of exhaled gas. The leak flow rate Q L Q is the rate of leakage from the patient interface system or elsewhere. Qr is the rate of air admitted into the patient's respiratory system.

[0339] Flow Therapy: A respiratory therapy that involves delivering airflow to the entrance of the airways at a controlled flow rate, called the therapeutic flow rate, that is typically positive throughout the patient's respiratory cycle.

[0340] Humidifier: The word humidifier shall be deemed to mean a humidification device positioned, installed, or physically constructed to provide a therapeutically beneficial amount of water (H2O) vapor to an airstream to improve the medical respiratory condition of a patient.

[0341] Leak: The word leak is considered to be an unintended flow of air. In one example, a leak can occur as a result of an imperfect seal between the mask and the patient's face. In another example, a leak can occur at the swivel elbow to the perimeter.

[0342] Conducted (acoustic) noise: Conducted noise, as used herein, refers to noise that is carried to the patient by pneumatic pathways, such as the air circuit and the 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.

[0343] Radiated (acoustic) noise: Radiated noise herein refers to noise that is carried to the patient by the surrounding air. In one form, radiated noise may be quantified by measuring the volume / pressure level of the object in question according to ISO 3744.

[0344] Ventilation (acoustic) noise: Ventilation noise herein refers to the noise generated by airflow through any ventilation, such as the ventilation holes of the patient interface.

[0345] Oxygen-enriched air: Air having an oxygen concentration greater than atmospheric concentration (21%), such as at least about 50% oxygen, at least about 60% oxygen, at least about 70% oxygen, at least about 80% oxygen, at least about 90% oxygen, at least about 95% oxygen, at least about 98% oxygen, or at least about 99% oxygen. "Oxygen-enriched air" is sometimes referred to as "oxygen" for short.

[0346] Medical Oxygen: Medical oxygen is defined as oxygen-enriched air with an oxygen concentration of 80% or greater. Patient: A person, whether or not suffering from a respiratory condition.

[0347] Pressure: force per unit area. Pressure is measured in cmH2O, gf / cm 2 1 cmH2O can be expressed in a variety of units, including 1 g-f / cm 2 which is approximately 0.98 hectopascals (1 hectopascal = 100 Pa = 100 N / m 2 = 1 mbar to 0.001 atm). In this specification, pressures are given in units of cmH2O unless otherwise stated.

[0348] The pressure in the patient interface is given the symbol Pm and the therapeutic pressure which represents the target value to be achieved by the interface pressure Pm at the current instant is given the symbol Pt.

[0349] Respiratory pressure therapy: is the application of air at a treatment pressure, typically positive relative to the atmosphere, to the entrance of the airways.

[0350] Ventilator: A mechanical device that provides pressure support to a patient to perform some or all of the work of breathing.

[0351] 4.6.1.1 Material Silicone or silicone elastomer: Synthetic rubber. In this specification, reference to silicone is a reference to liquid silicone rubber (LSR) or compression molded silicone rubber (CMSR). One form of commercially available LSR is SILASTIC (included within the range of products sold under this trademark) manufactured by Dow Corning. Another LSR manufacturer is Wacker. Unless otherwise specified, exemplary forms of LSR have a Shore A (or Type A) indentation hardness in the range of about 35 to about 45 as measured by ASTM D2240.

[0352] Polycarbonate: A thermoplastic polymer of bisphenol A carbonate.

[0353] 4.6.1.2 Mechanical properties Resilience: The ability of a material to absorb energy when elastically deformed and release the energy when the load is removed.

[0354] Elasticity: Virtually all of the energy is released when unloaded. Examples include certain silicone and thermoplastic elastomers.

[0355] Hardness: the ability of a material to resist deformation (expressed, for example, by Young's modulus or by the indentation hardness scale measured on a standardized sample size). "Soft" materials may include silicone or thermoplastic elastomers (TPEs) and may deform easily, for example under finger pressure. "Hard" materials may include polycarbonate, polypropylene, steel or aluminum, and do not easily deform under finger pressure, for example.

[0356] Stiffness (or Rigidity) of a Structure or Component: The ability of a structure or component to resist deformation in response to an applied load. The load can be a force or a moment (e.g., compression, tension, bending, or torsion). A structure or component may offer different resistance in different directions. The opposite of stiffness is flexibility.

[0357] Floppy Structure or Component: A structure or component that, when forced to support its own weight, changes shape (e.g., bends) within a relatively short period of time (e.g., one second).

[0358] Rigid Structure or Component: A structure or component that does not change shape substantially when subjected to loads typically encountered in use. An example of such an application is establishing and maintaining a patient interface in a sealing relationship with the entrance to a patient's airway, e.g., under a pressure load of approximately 20-30 cmH2O.

[0359] As one example, an I-beam may have a different bending stiffness (resistance to bending load) in a first direction compared to a second orthogonal direction, hi another example, a structure or component may be floppy in a first direction and rigid in a second direction.

[0360] 4.6.2 Respiratory cycle Apnea: According to some definitions, apnea is said to occur when flow rate falls below a predefined threshold for a period of time, e.g., 10 seconds. Obstructive apnea is said to occur when a partial obstruction of the airway prevents airflow despite the patient's efforts. Central apnea is said to occur when apnea is detected due to reduced or absent respiratory effort despite a patent airway. Mixed apnea occurs when reduced or absent respiratory effort coincides with an obstructed airway.

[0361] Respiratory rate: the patient's spontaneous breathing rate, usually measured in breaths per minute.

[0362] Duty cycle: The ratio of inspiration time Ti to total breathing time Ttot.

[0363] Effort (breathing): The effort required by a spontaneous breather to breathe.

[0364] Expiratory portion of the respiratory cycle: the period from the start of the expiratory flow to the start of the inspiratory flow.

[0365] Flow limitation: Flow limitation is considered to be a condition in a patient's breathing where an increase in the patient's effort does not result in a corresponding increase in flow. If flow limitation occurs during the inspiratory portion of the respiratory cycle, it may be described as inspiratory flow limitation. If flow limitation occurs during the expiratory portion of the respiratory cycle, it may be described as expiratory flow limitation. Flow-limited inspiratory waveform types: (i) Flattening: There is an upswing followed by a relatively flat section, then a downswing. (ii) M-shape: It has two local peaks, one at the leading edge and one at the trailing edge, with a relatively flat area between the two peaks. (iii) Chair Shape: Has a single local peak at the leading edge followed by a relatively flat section. (iv) Reverse chair shape: A relatively flat section followed by a single local peak, this peak being at the trailing edge.

[0366] Hypopnea: By some definitions, hypopnea is considered a reduction in flow but not a cessation of flow. In one form, hypopnea may be said to occur when flow is reduced below a threshold rate for a period of time. Central hypopnea is said to occur when hypopnea is detected due to a reduction in respiratory effort. In one form in adults, hypopnea may be considered when any of the following occur: (i) A 30% decrease in patient breathing for at least 10 seconds and an associated 4% desaturation; or (ii) A reduction in patient respiration (but less than 50%) for at least 10 seconds and associated desaturation or agitation of at least 3%.

[0367] Hyperventilation: An increase in airflow to a higher than normal level.

[0368] Inspiration portion of the respiratory cycle: The period from the start of the inspiratory flow to the start of the expiratory flow is taken as the inspiration portion of the respiratory cycle.

[0369] Patency (Airway): The degree to which the airway is open, or the extent to which the airway is open. A patent airway is open. Airway patency may be quantified, for example, as a value of one (1) for an open state and a value of zero (0) for a closed (occluded) state.

[0370] Positive end-expiratory pressure (PEEP): The pressure in the lungs above atmosphere that exists at the end of expiration.

[0371] Peak Flow (Qpeak): The maximum value of flow during the inspiratory portion of the respiratory flow waveform.

[0372] Respiratory flow, patient flow, respiratory flow (Qr): These terms may be understood to refer to the estimate of respiratory flow by an RPT device, as distinct from "true respiratory flow" or "true respiratory flow", which is the actual respiratory flow experienced by the patient, usually expressed in liters per minute.

[0373] Tidal Volume (Vt): The volume of air inspired or expired during normal breathing when no extra effort is applied. In principle, the inspiration volume Vi (volume of air inspired) is equal to the expiration volume Ve (volume of air expired), so a single tidal volume Vt can be defined as equal to either volume. In practice, the tidal volume Vt is estimated as some combination (e.g., the average of the inspiration volume Vi and expiration volume Ve).

[0374] (Inspiration) Time (Ti): The duration of the inspiratory portion of the respiratory flow waveform.

[0375] (Expiratory) Time (Te): The duration of the expiratory portion of the respiratory flow waveform.

[0376] Total) Time (Ttot): The total duration between the start of one inspiratory portion of the respiratory flow waveform and the start of the next inspiratory portion of the respiratory flow waveform.

[0377] Typical Recent Ventilation: The ventilation value around which the most recent values ​​of ventilationVent tend to cluster over a given time scale (i.e., the degree to which the most recent values ​​of ventilation tend to be central).

[0378] Upper Airway Obstruction (UAO): Includes both partial and total upper airway obstruction. This can be associated with a state of flow limitation where flow increases slightly or may even decrease as the pressure difference across the upper airway increases (Starling resistance behavior).

[0379] Vent: A measure of the rate of gas exchange performed by a patient's respiratory system. Measures of ventilation may include either or both of the inhaled and exhaled airflow per unit time. When expressed as volume per minute, this amount is often called "minute ventilation." Minute ventilation is sometimes given simply as volume, which is understood to be volume per minute.

[0380] 4.6.3 Ventilation Adaptive servo ventilator (ASV): A servo ventilator that has a variable, rather than fixed, target ventilation that can be learned from some characteristics of the patient, for example the patient's breathing characteristics.

[0381] Backup Rate: A ventilator parameter that sets the minimum number of breaths (typically breaths per minute) that the ventilator will deliver to the patient unless triggered by spontaneous breathing effort.

[0382] Cycled: The end of the inspiratory phase of the ventilator. When a ventilator delivers breaths to a spontaneously breathing patient, at the end of the inspiratory portion of the breathing cycle, the ventilator is said to be cycled to stop delivering breaths.

[0383] Expiratory Positive Airway Pressure (EPAP): The base pressure to which varying pressures are applied within a breath to produce the desired interface pressure the ventilator attempts to achieve at a given time.

[0384] End-Expiratory Pressure (EEP): The desired interface pressure that the ventilator attempts to achieve at the end of the expiratory portion of an exhalation. If the pressure waveform template Π(Φ) is zeroed at the end of exhalation when Π=1, i.e., Π(Φ)=0, then EEP is equal to EPAP.

[0385] Inspiratory Positive Airway Pressure (IPAP): The maximum desired interface pressure that the ventilator attempts to achieve during the inspiratory portion of the breath.

[0386] Pressure Support: A measure of the pressure the ventilator is increasing above the pressure the ventilator is increasing above, typically referring to the difference in pressure between the maximum and base pressures during inspiration (e.g., PS=IPAP-EPAP). In some situations, pressure support refers to the difference the ventilator attempts to achieve, rather than the difference it actually achieves.

[0387] Servo Ventilator: A ventilator that measures patient ventilation, has a target ventilation, and adjusts the level of pressure support to move patient ventilation toward the target ventilation.

[0388] Spontaneous / Timed (S / T): A mode of a ventilator or other device that attempts to detect the onset of a breath in a spontaneously breathing patient. If the device does not detect a breath within a predetermined period of time, the device automatically begins delivering a breath.

[0389] Swing: A term equivalent to pressure support.

[0390] Triggering: When a ventilator or other respiratory therapy device (such as an RPT device or a portable oxygen concentrator device) delivers a constant amount of breathable gas to a spontaneously breathing patient, this is called a trigger. Due to the patient's efforts, the trigger usually occurs at or near the beginning of the respiratory portion of the respiratory cycle.

[0391] 4.6.3.1 Structure of the respiratory system Diaphragm: sheet of muscle that spans the base of the thoracic cavity. It separates the thoracic cavity, which contains the heart, lungs, and ribs, from the abdominal cavity. When the diaphragm contracts, it increases the volume of the thoracic cavity and draws air into the lungs.

[0392] Larynx: The larynx, or voice box, houses the vocal cords and connects the lower part of the pharynx (hypopharynx) with the trachea.

[0393] Lungs: human respiratory system. The conducting zone of the lungs includes the trachea, bronchi, bronchioles and terminal bronchioles. The respiratory zone includes the respiratory bronchioles, alveolar ducts and alveoli.

[0394] Nasal cavity: The nasal cavity (or nasal fossa) is a large air-filled space in the center of the face above and behind the nose. The nasal cavity is divided into two by a vertical fin called the nasal septum. On either side of the nasal cavity are three horizontal extensions called the nasal turbinates (conchae) or turbinates. At the front of the nasal cavity is the nose, which merges dorsally into the nasopharynx via the posterior nares.

[0395] Pharynx: part of the throat just below the nasal cavity and above the esophagus and larynx. The pharynx is usually divided into three parts: the epipharynx (nasal part of the pharynx), the mesopharynx (oral part of the pharynx), and the hypopharynx.

[0396] 4.6.4 Patient Interface Anti-Asphyxiation Valve (AAV): A component or subassembly of a mask system that reduces the risk of the patient rebreathing carbon dioxide (CO2) by venting to the atmosphere in a fail-safe manner.

[0397] Elbow: An elbow is an example of a structure that directs the airflow axis to redirect through an angle. In one form, the angle may be approximately 90 degrees. In another form, the angle may be greater than or less than 90 degrees. The elbow may have a generally circular cross section. In another form, the elbow may have an elliptical or rectangular cross section. In certain forms, the elbow may be rotatable, for example, about 360 degrees, relative to the mating component. In certain forms, the elbow may be removable from the mating component, for example, via a snap connection. In certain forms, the elbow may be assembled to the mating component via a one-time snap at the time of manufacture, but cannot be removed by the patient.

[0398] Frame: Frame is taken to mean a mask structure that supports a tensile load between two or more points that connect the headgear. A mask frame may be a non-airtight load-bearing structure in the mask. However, some forms of mask frames may be airtight.

[0399] Headgear: Headgear is a positioning and stabilizing structure designed for the head. For example, the headgear may include one or more sets of posts, ties, and stiffeners configured to position and hold the patient interface in position for respiratory therapy on the patient's face. Some ties are formed of soft, flexible, and resilient materials, such as laminated composites of foam and fabric.

[0400] Membrane: Membrane is taken to mean a typically thin-walled element, preferably offering substantially no resistance to bending and resistance to stretching.

[0401] Plenum Chamber: Mask plenum chamber is taken to mean a part of a patient interface having a wall that at least partially encloses a volume of space, the air in the volume being pressurized to exceed atmospheric pressure in use. The shell may form part of the wall of the mask plenum chamber.

[0402] Seal: When used as a noun ("seal") it can refer to a structure, and when used as a verb ("seal") it can refer to an effect. Two elements can be constructed and / or arranged to achieve a "seal" or "seal" between them, but not require a separate "seal" element per se.

[0403] Shell: A shell is taken to mean a curved, relatively thin structure that has bending, tensile, and compressive stiffness. For example, the curved structural wall of a mask may be a shell. In some forms, the shell may be faceted. In some forms, the shell may be airtight. In some forms, the shell may not be airtight.

[0404] Stiffener: A stiffener is taken to mean a structural component designed to increase the bending resistance of another component in at least one direction.

[0405] Strut: A strut is taken to mean a structural component designed to increase the compressive resistance of another component in at least one direction.

[0406] Swivel (noun): A subassembly of components configured to rotate, preferably independently, about a common axis, preferably under low torque. 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 connection with an air delivery conduit, the subassembly of components preferably includes a mating cylindrical conduit. In use, there may be little or no leakage of air flow from the swivel.

[0407] Tie (noun): A structure designed to resist tension.

[0408] Ventilator: (noun): A structure that allows airflow from the interior of the mask or conduit to the ambient air to clinically effectively flush exhaled gases. For example, for clinically effective flushing, flow rates of about 10 liters / minute to about 100 liters / minute may be used depending on the mask design and therapeutic pressure.

[0409] 4.7 Other precautions A portion of the disclosure of this patent specification contains material that is subject to copyright protection. The copyright owner has no objection to anyone copying the patent specification or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.

[0410] Where a range of values ​​is provided, unless the context clearly dictates otherwise, it is understood that to the tenth of the unit of the lower limit, each intervening value between the upper and lower limits of that range, and any other stated or intervening value in that stated range, is encompassed within the invention. The upper and lower limits of these intervening ranges, which may be independently included within an intervening range, are also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding one or both of those included limits are also included in the invention.

[0411] Furthermore, when a value(s) is described herein as being implemented as part of the present invention, unless otherwise noted, such value(s) may be approximate, and it is understood that such values ​​may be utilized to any suitable significant figure to the extent that practical technical implementations may permit or require.

[0412] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, a limited number of exemplary methods and materials are described herein.

[0413] Although particular materials are described as being preferred for use in the construction of a component, obvious alternative materials having similar properties may be substituted. Further, unless otherwise specified to the contrary, any components described herein are understood to be manufacturable and therefore may be manufactured together or separately.

[0414] Please note that as used in this specification and the appended claims, the singular forms "a," "an," and "the" include their plural equivalents unless the context clearly dictates otherwise.

[0415] All publications mentioned herein are incorporated herein by reference in their entirety to disclose and describe the methods and / or materials that are the subject of the publication. The publications discussed herein are provided solely for their disclosure prior to the filing date of this application. Nothing herein should be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates, which may need to be independently confirmed.

[0416] The terms "comprises" and "comprising" should be construed as referring to elements, components, or steps in a non-exclusive manner, indicating that a referenced element, component, or step can be present in, utilized in, or combined with other elements, components, or steps that are not specifically referenced.

[0417] The subject headings used in the detailed description are included for ease of reference to the reader only and should not be used to limit the subject matter found throughout this disclosure or the claims. The subject headings should not be used in interpreting the claims or claim limitations.

[0418] Although the technology herein has been described with reference to specific examples, it should be understood that these examples are merely illustrative of the principles and applications of the technology. In some instances, terms and symbols may suggest specific details that are not necessary for the practice of the invention. For example, the terms "first" and "second" may be used, but unless otherwise specified, these terms are not intended to indicate any order and may be utilized to distinguish separate elements. Furthermore, although process steps in a methodology may be described or illustrated in a sequence, such ordering is not required. Those skilled in the art will recognize that such ordering may be changed and / or aspects may occur simultaneously or even synchronously.

[0419] It is therefore to be understood that numerous modifications may be made in the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0420] 4.8 List of selected reference symbols 1000 patients 1100 Bedmate 3000 Patient Interface 3100 Seal forming structure 3200 Plenum Chamber 3300 Positioning and stabilizing structures 3400 Ventilation section 3600 Connection Port 3700 Forehead support 3800 Patient Interface 4000 RPT Devices 4010 Outer Housing 4012 Upper part 4014 Lower part 4015 Panel 4016 Chassis 4018 Handle 4020 Pneumatic Block 4110 Air Filter 4112 Inlet Air Filter 4120 Muffler 4122 Inlet muffler 4124 Exit muffler 4140 Pressure Generator 4142 Blower 4144 Motor 4160 Spillback Prevention Valve 4170 Air Circuit 4180 Refill Gas 4200 Electrical Components 4202 PCBA 4210 Power supply 4220 Input Device 4230 Central Controller 4232 Clock 4240 Therapy Device Controller 4250 protection circuit 4260 Memory 4270 Transducer 4272 Pressure Sensor 4274 Flow Sensor 4276 Motor Speed ​​Transducer 4280 Data Communication Interface 4282 Remote External Communications Network 4284 local external communications network 4286 Remote External Device 4288 local external connection 4290 output device 4292 Display Driver 4294 Display 4300 Algorithm 4310 Pretreatment Module 4312 Interface Pressure Estimation Algorithm 4314 Ventilation Flow Estimation Algorithm 4316 Leakage flow rate estimation algorithm 4318 Respiratory flow estimation algorithm 4320 Therapy Engine Module 4321 Phase Determination Algorithm 4322 Waveform Algorithm 4323 Ventilation Decision Algorithm 4324 Inspiratory Flow Limitation Decision Algorithm 4325 Apnea / Hypopnea Decision Algorithm 4326 Snoring Determination Algorithm 4327 Airway Patency Determination Algorithm 4328 Target ventilation decision algorithm 4329 Therapy Parameter Decision Algorithm 4330 Therapy Control Module 4340 method 4500 methods 4520 steps 4530 Steps 4540 Steps 4550 steps 4560 steps 5000 humidifier 5002 Humidifier inlet 5004 Humidifier outlet 5006 Humidifier Base 5110 Humidifier Reservoir 5120 Conductive part 5130 Reservoir Dock 5135 Lock lever 5150 Water Level Indicator 5240 heating element 6000 Valve Assembly 6010 valve housing 6012 Upstream housing part 6014 Downstream housing part 6020 Pressure operated valve components 6030 Inlet / RPT port 6040 Outlet / Patient Interface Port 6050 Ventilation / Perimeter Ports 6052 Ventilation opening 6060 diaphragm 6070 Circumference 6080 Retaining Flange 6090 One-way valve / Duckbill valve 6100 Membrane part 6102 Membrane section / membrane part 6110 Pressure Sensor (Patient Interface) 6120 Recess 6130 Rib 6140 1st wall 6150 Rib 6160 Lip end 6170 Opening 6180 Flow guide part 6190 Lamp 6200 side wall 6210 Upper edge 6220 Chamber 7000HMX 7010 Moisture absorbent 7020 Frame members L Valve base length W Valve base width

Claims

1. A combination one-way inhalation valve-exhalation discharge valve assembly for controlling airflow in a respiratory treatment system for delivering pressurized air to an entrance of a patient's airways, the respiratory treatment system being configured to maintain a therapy pressure within a range suitable for treating a respiratory disorder; The combination one-way inhalation valve-exhalation discharge valve assembly comprises: a housing including a valve inlet, a valve outlet, and at least one ventilation opening; a diaphragm sealingly connected to the housing at an outer periphery of the diaphragm, dividing the housing into a) an upstream portion in fluid communication with the valve inlet, and b) a downstream portion in fluid communication with the valve outlet; the diaphragm has an oval, elliptical, or stadium shape; an inner portion of the diaphragm defining a one-way intake valve; The one-way intake valve is permitting flow from the valve inlet to the valve outlet when the pressure in the upstream portion of the housing exceeds the pressure in the downstream portion of the housing; configured to reduce or prevent flow from the valve inlet to the valve outlet when the pressure in the downstream portion is greater than the pressure in the upstream portion; an outer portion of the diaphragm defining the exhalation release valve; The exhalation release valve is allowing flow from the downstream portion of the housing to ambient atmosphere through the at least one ventilation opening when the pressure in the downstream portion exceeds the pressure in the upstream portion; a combination one-way inhalation valve-exhalation discharge valve assembly configured to reduce or prevent flow from the downstream portion of the housing through the at least one ventilation opening to ambient atmosphere when the pressure in the upstream portion exceeds the pressure in the downstream portion.

2. 2. The combination one-way inhalation valve-exhalation discharge valve assembly of claim 1, wherein the diaphragm has an elongated shape and the ratio of the major axis length of the diaphragm to the minor axis length of the diaphragm is at least 4:

3.

3. 3. The combination one-way inhalation valve-exhalation discharge valve assembly of claim 2, wherein the one-way valve structure is configured as a duckbill valve, the base of the duckbill valve having a length dimension substantially parallel to a major axis of the diaphragm and a width dimension substantially parallel to a minor axis of the diaphragm, the length being greater than the width.

4. 4. The combination one-way inhalation valve-exhalation discharge valve assembly of claim 3, wherein the ratio of said length to said width is at least 1.5:1 or 2:

1.

5. The combination one-way inhalation valve-exhalation discharge valve assembly of any one of claims 1 to 4, wherein the diaphragm includes an outer retention flange.

6. 6. The combination one-way inhalation valve-exhalation discharge valve assembly of claim 5, wherein said diaphragm has a cylindrical wall, said outer retention flange being disposed at one end of said cylindrical wall.

7. The combination one-way inhalation valve-exhalation discharge valve assembly of any one of claims 1 to 4, wherein a first portion of the diaphragm has at least one material or physical property that is different from an adjacent portion of the diaphragm.

8. 8. The combination one-way inhalation valve-exhalation discharge valve assembly of claim 7, wherein a first portion of the diaphragm is made of a different material than adjacent portions.

9. The combination one-way inhalation valve-exhalation discharge valve assembly of any one of claims 1 to 4, wherein the diaphragm is integrally made of a single material.

10. A combination one-way inhalation valve-exhalation discharge valve assembly according to any one of claims 1 to 4, wherein the diaphragm has regions of different thickness.

11. 11. The combination one-way inhalation valve-exhalation discharge valve assembly of claim 10, wherein one of the regions has a thickness at least twice the thickness of the other region.

12. 12. The combination one-way inhalation valve-exhalation discharge valve assembly of claim 11, wherein one of the regions has a thickness that is 2 to 8 times the thickness of the other region.

13. 11. The combination one-way inhalation valve-exhalation discharge valve assembly of claim 10, wherein the one-way inhalation valve has a first region having a first thickness and a second region adjacent the first region having a second thickness.

14. 11. The combination one-way inhalation valve-exhalation discharge valve assembly of claim 10, wherein the exhalation discharge valve has a first region having a first thickness and a second region adjacent the first region having a second thickness.

15. A combination one-way inhalation valve-exhalation discharge valve assembly according to any one of claims 1 to 4, wherein said diaphragm has only one axis of symmetry.

16. 5. The combination one-way inhalation valve-exhalation discharge valve assembly of claim 1, wherein the at least one ventilation opening comprises a plurality of ventilation openings spaced around the circumference of the downstream portion of the housing.

17. 5. A combination one-way inhalation valve-exhalation discharge valve assembly according to claim 1, wherein the downstream portion of the housing includes the valve outlet, the diaphragm includes a pair of lips that are forced toward each other to seal a path to a patient interface port when pressure in the downstream portion exceeds pressure in the upstream portion, and the pair of lips form an opening to allow airflow to pass toward a patient interface port inlet when pressure in the upstream portion of the housing exceeds pressure in the downstream portion.

18. 18. The combination one-way inhalation valve-exhalation discharge valve assembly of claim 17, wherein each ventilation opening is provided with a flow guide, each flow guide configured to avoid or minimize a) sharp corners, b) acute angles, and c) sudden expansion of exhaled gases flowing from the valve outlet to the corresponding ventilation opening when the pressure in the downstream portion exceeds the pressure in the upstream portion.

19. 20. The combination one-way inhalation valve-exhalation discharge valve assembly of claim 18, wherein each flow guide includes a ramp portion that guides exhalation airflow to the entrance of the ventilation opening.

20. 20. The combination one-way inhalation valve-exhalation discharge valve assembly of claim 19, wherein each of the flow guides includes a sidewall portion on either side of each of the corresponding ramp portions.

21. A patient interface system for supplying airflow generated by a blower to a patient, the patient interface system comprising a combination one-way inhalation valve-exhalation discharge valve assembly according to any one of claims 1 to 4.

22. 1. A respiratory therapy system for delivering pressurized air to an entrance of a patient's airways, comprising: a. a blower that generates the pressurized air; b. a patient interface for sealing the delivery of pressurized air to the patient's airway; and c) a combination one-way inhalation valve-exhalation valve assembly according to any one of claims 1 to 4 for controlling airflow to the patient interface.

23. 23. The respiratory treatment system of claim 22, further comprising a pressure sensor configured to measure pressure within the patient interface, the respiratory treatment system controlling the blower based on data from the pressure sensor.

24. 24. The respiratory treatment system of claim 23, wherein the pressure sensor reduces flow from the blower when the patient exhales.

25. 23. The respiratory treatment system of claim 22, wherein the respiratory treatment system further includes a conduit for delivering pressurized air to the patient interface, and wherein the combination one-way inhalation valve-exhalation discharge valve assembly is included in the conduit or the patient interface.

26. 23. The respiratory treatment system of claim 22, wherein the respiratory treatment system includes a portable integrated blower / patient interface system wearable on the patient's face or head.

27. 23. The respiratory treatment system of claim 22, wherein the respiratory treatment system is configured to be powered by one or more batteries.

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