Monitoring respiratory pressure therapy

Abstract

Methods and apparatus provide for automatic circuit disconnect monitoring, such as for respiratory apparatus or systems. Disconnection of a patient circuit, including a patient interface and an air delivery circuit, can be detected and a message or alarm activated. In some versions, the occurrence of a circuit disconnect event can be detected based on a change in a disconnect set value, such as by a processor, from a transient disconnect parameter. The disconnect set value can be determined based on the patient circuit type. The transient disconnect parameter can be determined from detected pressure and flow, and can be, for example, a conductance value or an impedance value. The disconnect event can be discriminated by one or more detected respiratory indicators. In some cases, transient impedance or conductance can be used to assess reconnection of the patient circuit, detect flow starvation, determine triggering and cyclic respiratory shape, and detect patient or circuit occlusion.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of Australian Provisional Patent Application No. AU2015903275, filed on August 14, 2015, the disclosure of which is incorporated herein by reference. Technical Field

[0003] This technology relates to one or more of the detection, diagnosis, treatment, prevention, and improvement of respiratory-related disorders. This technology also relates to medical devices or equipment and their uses. Specifically, this technology relates to monitoring the delivery of treatment in a respiratory device by determining the conductivity or impedance in the patient circuit. Background Technology

[0004] Human respiratory system and its disorders

[0005] The human respiratory system facilitates gas exchange. The nose and mouth form the airway entrance for the patient.

[0006] The airways consist of a series of branching tubes, which become narrower, shorter, and more numerous as they penetrate deeper into the lungs. The primary function of the lungs is gas exchange, allowing oxygen to enter the venous blood from the air and carbon dioxide to be expelled. The trachea divides into the left and right main bronchioles, which eventually branch into terminal bronchioles. The bronchi form the conduction airways but do not participate in gas exchange. Other branches of the airways lead to the respiratory bronchioles and ultimately to the alveoli. The alveolar region of the lungs is where gas exchange occurs and is called the respiratory zone. See *Respiratory Physiology*, 9th edition, published in 2011 by John B. West, Lippincott Williams & Wilkins.

[0007] There are a range of breathing disorders. Some disorders can be characterized by specific events, such as respiratory arrest, insufficiency, and hyperventilation.

[0008] Obstructive sleep apnea (OSA) is a form of sleep-disordered breathing (SDB) characterized by events involving closure or obstruction of the upper airway during sleep. It arises from a combination of abnormally small upper airway size and normal loss of muscle tone in the areas of the tongue, soft palate, and posterior oropharyngeal walls during sleep. This condition causes affected patients to stop breathing, typically for periods ranging from 30 to 120 seconds, sometimes 200 to 300 times per night. This often leads to excessive daytime sleepiness and can contribute to cardiovascular disease and brain damage. Concomitant symptoms are common, especially in middle-aged overweight men, but those affected may not be aware of the problem. See U.S. Patent No. 4,944,310 (Sullivan).

[0009] Cheyne-Stokes respiration (CSR) is another form of sleep-disordered breathing. CSR is a dysregulation of the patient's respiratory controller, characterized by rhythmic alternations of waxing and waning ventilation known as CSR cycles. CSR is characterized by repetitive hypoxia and reoxygenation of arterial blood. Due to the repetitive oxygen deprivation, CSR can be harmful. In some patients, CSR is associated with repetitive awakenings from sleep, leading to severe sleep disruption, increased sympathetic activity, and increased afterload. See U.S. Patent No. 6,532,959 (Berthon-Jones).

[0010] Respiratory failure is a broad term encompassing respiratory disorders in which the lungs are unable to inhale enough oxygen or exhale enough CO2 to meet the patient's needs, and is therefore characterized by abnormal blood gas tension. Respiratory failure may cover some or all of the following disorders.

[0011] Obesity hyperventilation syndrome (OHS) is defined as a combination of severe obesity and chronic hypercapnia at wakefulness, without any other known cause of hypoventilation. Symptoms include dyspnea, morning headache, and excessive daytime sleepiness.

[0012] Chronic obstructive pulmonary disease (COPD) encompasses any of a group of lower airway diseases that share certain common characteristics. These diseases include increased airflow resistance, prolonged expiratory portion of breathing, and loss of normal lung elasticity. Examples of COPD include emphysema and chronic bronchitis. COPD is caused by chronic smoking (a major risk factor), occupational exposure, air pollution, and genetic factors. Symptoms include exertional dyspnea, chronic cough, and sputum production.

[0013] Neuromuscular disease (NMD) is a broad term encompassing many diseases and ailments that impair muscle function directly through intrinsic muscle pathology or indirectly through neuropathology. Some NMD patients are characterized by progressive muscle damage that leads to loss of mobility, wheelchair use, dysphagia, respiratory muscle weakness, and ultimately death from respiratory failure. Neuromuscular disorders can be classified as rapidly progressive or slowly progressive: (i) rapidly progressive disorders: characterized by muscle damage that worsens over months and leads to death within years (e.g., amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD) in adolescents); (ii) variable or slowly progressive disorders: characterized by muscle damage that worsens over years and only slightly shortens life expectancy (e.g., limb-girdle type, facioscapulohumeral type, and ankylosing spondylitis). Symptoms of respiratory failure in NMD include: progressive general weakness, dysphagia, shortness of breath during and at rest, fatigue, somnolence, morning headache, difficulty concentrating, and mood swings.

[0014] The chest wall is a group of chest wall deformities that result in inefficient connection between the respiratory muscles and the thoracic cavity. These disorders are typically characterized by restrictive defects and have the potential to cause chronic hypercapnia-related respiratory failure. Scoliosis and / or kyphosis can cause severe respiratory failure. Symptoms of respiratory failure include: dyspnea during exercise, peripheral edema, orthopnea, recurrent chest infections, morning headache, fatigue, poor sleep quality, and loss of appetite.

[0015] A range of treatments have been used to treat or improve these symptoms. In addition, other healthy individuals may use these treatments to prevent respiratory distress.

[0016] Respiratory pressure therapy

[0017] Continuous positive airway pressure (CPAP) therapy has been used to treat obstructive sleep apnea (OSA). The mechanism of action is that CPAP acts as an air splint and can prevent upper airway obstruction by pushing the soft palate and tongue forward and away from the posterior oropharyngeal wall. Treatment for OSA with CPAP can be voluntary; therefore, patients may choose not to adhere to treatment if they find the device used to provide such treatment to be uncomfortable, difficult to use, expensive, or unsightly, or if so, in any of these ways.

[0018] Noninvasive ventilation (NIV) provides ventilatory support to patients through the upper airway to help them breathe and / or maintain adequate oxygen levels in the body by performing some or all of the work of breathing. Ventilatory support is delivered via a noninvasive patient interface. NIV has been used to treat chronic respiratory failure (CSR) and respiratory insufficiency in forms such as orthostatic hypoxia (OHS), chronic respiratory dysplasia (COPD), non-invasive respiratory disease (NMD), and chest wall disorders. In some forms, it can improve the comfort and effectiveness of these treatments.

[0019] Non-invasive ventilation (IV) provides ventilatory support for patients who are unable to breathe effectively on their own and can be delivered using a tracheostomy tube. In some forms, the comfort and effectiveness of these treatments can be improved.

[0020] Treatment System

[0021] These treatments can be provided by treatment systems or devices. Such systems and devices can also be used to diagnose symptoms without treating them.

[0022] The treatment system may include a respiratory pressure therapy device (RPT device), an air circuit, a humidifier, a patient interface, and data management.

[0023] Treatment systems may include a loop disconnection detection system that detects when a patient has been disconnected from the system. An example is the SmartStart CPAP and VPAP device described in US 6,240,921 and present in ResMed CPAP and VPAP devices such as the ResMed AirSense 10 CPAP device. TM Features. Depending on the patient’s impairment, appropriate actions may be automatic (a) to suspend treatment, (b) to terminate normal treatment and enter a non-therapeutic standby state for a variety of purposes, including conserving water or supplemental gas delivery, preventing reconnection, or (c) to issue an alarm in combination with (a) or (b), or, if possible, in combination with maintaining normal treatment.

[0024] An accidental disconnection along the gas flow path to a ventilator-dependent patient can be life-threatening; therefore, such systems may require an alarm to notify caregivers or clinicians upon patient disconnection. Many volumetric ventilators include a low-pressure alarm that can be configured to detect disconnection of a patient with certain circuit configurations and treatment modes. This relies on a pressure drop in the device due to a circuit disconnection that is significantly lower than the pressure present when connected, including during background leakage or strong patient effort. Such disconnection detection systems may generally not detect decannulation, such as with small tracheostomy tubes commonly used in infants and young children, with cuffless intubation associated with high leakage, with turbine-based ventilators that cannot withstand pressure drops due to their high flow capacity, or with oralpieces with high resistance. There is a general trend in non-invasive ventilation where even high leakage can be tolerated without pressure loss. With a wide range of variations in patient, circuit, ventilation mode, and ventilation technique, single-modal disconnection alarms (such as low pressure, high flow, high volume, and low volume) are unreliable in detecting disconnection in all cases.

[0025] A patient’s reconnection (if detected) can lead to the resumption of previous treatments or other appropriate actions to ensure the patient’s health status when connected to the device.

[0026] Patient Interface

[0027] A patient interface can be used to attach a breathing device to its wearer, for example, by providing an airflow into the airway. The airflow can be provided to the patient's nose and / or mouth via a mask, to the mouth via a tube, or to the patient's trachea via a tracheostomy tube. Depending on the treatment to be applied, the patient interface can form a seal with an area such as the patient's face, thereby facilitating the delivery of gas at a pressure sufficiently different from ambient pressure (e.g., a positive pressure of approximately 10 cmH2O relative to ambient pressure) to achieve the treatment. For other forms of treatment, such as oxygen delivery, the patient interface may not include a seal sufficient to facilitate the delivery of a gas supply at a positive pressure of approximately 10 cmH2O to the airway.

[0028] Sealing Formation Part

[0029] The patient interface may include a seal-forming portion. Because it comes into direct contact with the patient's face, the shape and construction of the seal-forming portion can directly affect the effectiveness and comfort of the patient interface.

[0030] The patient interface can be partially characterized based on the design intent of the sealing portion to engage with the face during use. In one form of patient interface, the sealing portion may include two sub-parts to engage with corresponding left and right nostrils. In another form of patient interface, the sealing portion may include a single element surrounding both nostrils during use. This single element may be designed, for example, to cover the upper lip and bridge of the nose area of ​​the face. In another form of patient interface, the sealing portion may include an element surrounding the mouth area during use, for example, by forming a seal on the lower lip area of ​​the face. In yet another form of patient interface, the sealing portion may include a single element surrounding both nostrils and the mouth area during use. These different types of patient interfaces can be given various names by their manufacturers, including nasal masks, full-face masks, nasal pillows, nasal sprays, and oronasal masks.

[0031] A series of patient interface sealing technologies are disclosed in the following patent applications assigned to ResMed Limited: WO 1998 / 004,310; WO 2006 / 074,513; WO 2010 / 135,785.

[0032] One form of nasal pillow was found in the Adam Circuit manufactured by Puritan Bennett. Another nasal pillow or nasal spray is the subject of U.S. Patent 4,782,832 (Trimble et al.), assigned to Puritan-Bennett Corporation.

[0033] ResMed Ltd. has manufactured the following products that combine a nose pillow: SWIFT TM Nose pillow mask, SWIFT TM II Nose pillow mask, SWIFT TM LT nose pillow mask, SWIFT TM FX Nose Pillow Mask and MIRAGE LIBERTY TM Full-face mask. The following patent application assigned to ResMed Ltd. describes an example of a nose pillow mask: International Patent Application WO 2004 / 073,778 (which describes a ResMed Ltd. SWIFT mask). TM Other aspects of the nose pillow); U.S. Patent Application 2009 / 0044808 (which describes ResMed Inc.'s SWIFT...) TM Other aspects of the LT nose pillow); International patent applications WO 2005 / 063,328 and WO 2006 / 130,903 (which describe ResMed Ltd. MIRAGE LIBERTY) TM Other aspects of the full-face mask); International Patent Application WO2009 / 052,560 (which describes ResMed Ltd.'s SWIFT)TM Other aspects of the FX nose pillow).

[0034] Positioning and stability

[0035] The sealing portion of the patient interface used in positive pressure therapy is subjected to a force corresponding to the air pressure that would disrupt the seal. Therefore, various techniques have been used to position the sealing portion and maintain it in a sealed relationship with the appropriate part of the face.

[0036] One technique involves using adhesives. See, for example, U.S. Patent Application Publication No. US 2010 / 0000534. However, using adhesives may be uncomfortable for some people.

[0037] Another technique is to use one or more straps and / or stabilizing harnesses. Many such harnesses suffer from one or more of the following: ill-fitting, bulky, uncomfortable, and awkward to use.

[0038] Respiratory Pressure Therapy (RPT) device

[0039] Air pressure generators are known in a range of applications, such as industrial-scale ventilation systems. However, air pressure generators for medical applications have specific requirements that are not met by more general air pressure generators, such as the reliability, size, and weight requirements of medical devices. Furthermore, even devices designed for medical use may have disadvantages related to one or more of the following: comfort, noise, ease of use, efficiency, size, weight, manufacturability, cost, and reliability.

[0040] One example of a specific requirement for certain RPT devices is noise.

[0041] Noise output level table for existing RPT devices (only one sample, measured in CPAP mode using the test method specified in ISO 3744 at 10 cmH2O).

[0042]

[0043] One known RPT device for treating sleep-disordered breathing is the ResMed S9 Sleep Therapy System. Another example of an RPT device is a ventilator. Ventilators such as the ResMed Stellar... TM The range of adult and pediatric ventilators can support a range of patients with invasive and non-invasive non-dependent ventilation for the treatment of a variety of conditions, such as, but not limited to, NMD, OHS and COPD.

[0044] ResMed Elis6e TM 150 ventilator and ResMed VS III TMVentilators provide support for invasive and non-invasive dependent ventilation suitable for adult or pediatric patients to treat a variety of conditions. These ventilators offer volumetric and pressure ventilation modes with single- or dual-branch circuits. RPT devices typically include a pressure generator, such as an electric motor-driven blower or a compressed gas reservoir, and are configured to supply airflow to the patient's airway. In some cases, airflow to the patient's airway can be supplied under positive pressure. The outlet of the RPT device is connected via an air circuit to a patient interface such as those described above.

[0045] The designer of a device may be presented with an almost infinite number of options. Design standards often conflict, meaning that some design choices are far from unconventional or unavoidable. Furthermore, certain aspects of comfort and efficiency may be highly sensitive to small and subtle changes in one or more parameters.

[0046] Humidifier

[0047] Delivering unhumidified airflow can lead to airway dryness. Humidifiers using an RPT device and patient interface generate humidified gas, minimizing nasal mucosal dryness and increasing patient airway comfort. Furthermore, in colder climates, warm air applied to the patient interface and the surrounding facial area is generally more comfortable than cold air. A range of artificial humidification devices and systems are known; however, they may not meet the specific requirements of medical humidifiers.

[0048] When needed, typically in areas where patients may sleep or rest (e.g., in hospitals), medical humidifiers are used to increase the humidity and / or temperature of an airflow relative to ambient air. Medical humidifiers intended for bedside placement can be very small. Medical humidifiers can be configured to humidify and / or heat only the airflow delivered to the patient, without humidifying and / or heating the patient's surrounding environment. Room-based systems (e.g., saunas, air conditioners, or evaporative coolers) may also humidify the air breathed by the patient; however, these systems also humidify and / or heat the entire room, which can cause discomfort to the occupant. Furthermore, medical humidifiers may have stricter safety restrictions than industrial humidifiers.

[0049] While many medical humidifiers are known, they may have one or more drawbacks. Some medical humidifiers may provide insufficient humidification, and some may be difficult or inconvenient for patients to use.

[0050] Data Management

[0051] There are many clinical reasons to obtain data to determine whether a patient is “adhering” to a prescription for respiratory pressure therapy, such as if the patient has been using their RPT device according to certain “adherence rules.” One example of an adherence rule for CPAP therapy is to require the patient to use their RPT device for at least four hours each night for at least 21 or 30 consecutive days to be considered adherent. To determine patient adherence, RPT device providers, such as healthcare providers, can manually obtain data describing the patient’s treatment with the RPT device, calculate usage over the predetermined time period, and compare it to the adherence rules. Once the healthcare provider has determined that the patient has been using their RPT device according to the adherence rules, the healthcare provider can inform the patient of the third part of adherence.

[0052] Patient treatment can benefit from other aspects of communication between treatment data and third-party or external systems.

[0053] Existing methods for communicating and managing such data may be one or more of the following: expensive, time-consuming, and error-prone. Summary of the Invention

[0054] This technology aims to provide medical devices for diagnosing, improving, treating or preventing respiratory disorders, which have one or more of the following: improved comfort, cost, efficacy, ease of use and manufacturability.

[0055] The first aspect of this technology relates to devices for diagnosing, improving, treating, or preventing respiratory disorders.

[0056] Another aspect of this technology relates to methods for diagnosing, improving, treating, or preventing respiratory disorders.

[0057] One aspect of certain forms of this technology is for providing methods and / or devices for detecting patient circuit disconnection.

[0058] Some embodiments of this technology include a method for detecting the occurrence of a loop disconnection event in a patient circuit of a respiratory device configured to supply pressurized airflow to a patient via the patient circuit. The method may include determining a disconnection setpoint based on the type of patient circuit. The method may include using one or more sensors to detect the pressure and flow rate of the pressurized airflow. The method may include calculating instantaneous disconnection parameters in a processor based on the detected pressure and flow rate. The method may include using the processor to detect the occurrence of a loop disconnection event based on changes in the disconnection setpoint using the instantaneous disconnection parameters.

[0059] In some models, the transient disconnect parameter can be a conductivity value. The transient disconnect parameter can be an impedance value. The disconnect setpoint can be a disconnect threshold. Detecting a loop disconnection event can include comparing the calculated transient disconnect parameter with the disconnect threshold.

[0060] The disconnection setting can be a profile, and detecting the occurrence of a loop disconnection event can include comparing multiple calculated instantaneous disconnection parameters with the profile.

[0061] In some embodiments, the method may include receiving patient-specific information from the respiratory device and using that information to determine a disconnect setting. The patient-specific information may include one or more of the patient's age, weight, height, and patient type. Optionally, the disconnect setting may be determined based on a lookup table stored in the respiratory device's memory. The method may include determining the type of patient circuit. The method may include receiving the type of patient circuit via the respiratory device's user interface. The type of patient circuit may include the configuration of the air circuit. The air circuit configuration may be at least one of ventilated, non-ventilated, single-branch and dual-branch, or single-branch and dual-branch. The type of patient circuit may include the type of patient interface. The type of patient interface may be at least one of invasive, non-invasive, ventilated, and non-ventilated.

[0062] In some cases, the method may include signaling the occurrence of a loop disconnection event upon detection. The method may include generating a response to the disconnection event upon detection. Generating a response to the disconnection event may include activating a message on the respiratory device's display. Generating a response to the disconnection event may include activating a disconnection alarm.

[0063] In some cases, the user interface of a breathing device is configured to have user control to silence the disconnect alarm for a predetermined period of time.

[0064] This method may include continuously detecting the occurrence of a loop disconnection event for a predetermined time limit before generating a response to the disconnection event. The predetermined time limit may be a set time between 5 seconds and 60 seconds. The predetermined time limit may be a predetermined number of breaths. The predetermined time limit may be adjusted via the user interface of the breathing device. This method may include calculating a transient disconnection parameter at least once per breath. This method may include calculating the transient disconnection parameter from the inspiratory phase of each breath. This method may include calculating the transient disconnection parameter at least once from the inspiratory phase of each breath and at least once from the expiratory phase of each breath. This method may include calculating the transient disconnection parameter at predetermined time intervals.

[0065] In some forms, the method may include determining a sensitivity setting and adjusting a disconnection setting based on the sensitivity setting. The method may include determining a sensitivity setting based on the type of patient circuit, according to a default sensitivity setting. The method may include determining the sensitivity setting from a testing phase. The testing phase may occur before the respiratory device provides respiratory therapy to the patient. The testing phase may occur while the respiratory device is providing respiratory therapy to the patient. The method may include generating a response to a disconnection event when a circuit disconnection event is detected from the testing phase. The sensitivity setting may be selected from a predetermined range of settings via the respiratory device's user interface. The predetermined range of settings may include values ​​between 1% and 100%. The predetermined range of settings may include values ​​provided in 5% increments between 5% and 95%. In some cases, the sensitivity setting for detecting a circuit disconnection event may be provided on the respiratory device's display.

[0066] In some forms, the method may include, upon detecting a circuit disconnection event, qualifying the detected event by monitoring respiratory indicators. In some cases, if respiratory indicators suggest the patient is still connected to the patient circuit, the method may include classifying the detected circuit disconnection event as false. In some cases, if respiratory indicators do not suggest the patient is still connected to the patient circuit, the method may include classifying the detected circuit disconnection event as true. Respiratory indicators may consist of one or more of the following: (i) expiratory flow rate indicating expiratory effort; (ii) inspiratory flow rate indicating inspiratory effort; (iii) the difference between an instantaneous disconnection parameter calculated from the inspiratory phase and an instantaneous parameter calculated from the expiratory phase; (iv) a comparison of the variance of the instantaneous disconnection parameter with a previous value of the instantaneous disconnection parameter; and (v) the change of the instantaneous disconnection parameter over time during the respiratory phase.

[0067] In some embodiments, the method may include comparing the detected flow rate with a predetermined threshold to confirm the occurrence of a loop disconnection event upon detection. The method may also include detecting reconnection of the patient circuit to the patient after the loop disconnection event has been detected. Reconnection of the patient circuit to the patient can be detected by comparing a transient disconnection parameter with a second threshold. Reconnection of the patient circuit to the patient can also be detected by detecting abrupt changes in the transient disconnection parameter.

[0068] Some embodiments of this technology may include a method for detecting the occurrence of a loop disconnection event in a patient circuit of a respiratory device configured to supply a pressurized airflow to a patient via the patient circuit. The method may include using one or more sensors to repeatedly detect the pressure and flow rate of the pressurized airflow. The method may include repeatedly calculating transient disconnection parameters in a processor based on the detected pressure and flow rate. The method may include comparing the processor with successive transient disconnection parameters to determine the level of variability of the transient disconnection parameters over time. The method may include detecting the occurrence of a loop disconnection event using the processor based on the level of variability. In some embodiments, the transient disconnection parameter may be a conductivity value. The transient disconnection parameter may be an impedance value.

[0069] Some embodiments of this technology may include a system for detecting the occurrence of a loop disconnection event in a patient circuit of a respiratory device configured to supply pressurized airflow to a patient via the patient circuit. The system may include a controller having at least one processor to access data representing pressure and flow rate of the pressurized airflow detected by one or more sensors. The controller may be configured to determine a disconnection setpoint based on the type of patient circuit. The controller may be configured to calculate an instantaneous disconnection parameter based on the accessed data representing pressure and flow rate. The controller may be configured to detect the occurrence of a loop disconnection event based on changes in the instantaneous disconnection parameter according to the disconnection setpoint. The instantaneous disconnection parameter may be a conductivity value. The instantaneous disconnection parameter may be an impedance value.

[0070] In some versions of this system, the disconnect setpoint can be a disconnect threshold, and the controller can be configured to compare calculated instantaneous disconnect parameters with the disconnect threshold to detect the occurrence of a loop disconnect event. The disconnect setpoint can be a distribution map, and the controller can be configured to compare multiple calculated instantaneous disconnect parameters with the distribution map to detect the occurrence of a loop disconnect event. The controller can be further configured to receive patient-specific information and use that information to determine the disconnect setpoint. Patient-specific information may include one or more of the patient's age, weight, height, and patient type. The controller can be configured to determine the disconnect setpoint based on a lookup table stored in the respiratory device's memory.

[0071] The controller can be configured to determine the type of patient circuit. The controller can be configured to receive the type of patient circuit via the user interface of the respiratory device. The type of patient circuit may include an air circuit configuration, and the air circuit configuration may be at least one of invasive, non-invasive, ventilated, non-ventilated, single-branch, and dual-branch. The controller can be configured to provide an indication of the circuit connection status on the user interface of the respiratory device. The controller can be configured to generate a response to a circuit disconnection event by activating a message on the user interface of the respiratory device. The controller can be configured to generate a response to a circuit disconnection event by activating a disconnection alarm. The controller can be configured to silence the disconnection alarm for a predetermined period of time in response to user activation of user control over the user interface of the respiratory device. The controller can be configured to prevent activation of the disconnection alarm until a predetermined time limit is reached after continuous detection of a circuit disconnection event. The predetermined time limit may be a set time between 5 seconds and 60 seconds. The predetermined time limit may be a predetermined number of breaths. The predetermined time limit may be adjustable.

[0072] In some configurations, the controller can be configured to calculate the transient disconnection parameter at least once per breath. The controller can be configured to calculate the transient disconnection parameter from the inspiratory phase of each breath. The controller can be configured to calculate the transient disconnection parameter at least once from the inspiratory phase of each breath and at least once from the expiratory phase of each breath. The controller can be configured to calculate the transient disconnection parameter at predetermined time intervals.

[0073] In some models, the controller can be further configured to determine a sensitivity setpoint and adjust the sensitivity of the disconnection setpoint based on the sensitivity setpoint. The controller can be configured to determine a default sensitivity setpoint based on the type of patient circuit. The controller can be configured to determine the sensitivity setpoint from a testing phase. The testing phase can occur before the respiratory device provides respiratory therapy to the patient. The testing phase can occur while the respiratory device may be providing respiratory therapy to the patient. During the testing phase, activation of the disconnection alarm can be disabled. The sensitivity setpoint can be selected from a predetermined setpoint range via the respiratory device's user interface. The predetermined setpoint range can include values ​​between 1% and 100%. The predetermined setpoint range can include values ​​provided in 5% increments between 5% and 95%. Optionally, a sensitivity setpoint indication can be provided on the respiratory device's display. The sensitivity setpoint indication can provide an indication of whether a disconnection event was detected using the determined sensitivity setpoint.

[0074] In some versions of this system, the controller may be further configured to screen for the occurrence of a determined loop disconnection event by monitoring respiratory indicators that suggest the patient may still be connected to the patient circuit if a loop disconnection event is determined to have occurred. If the respiratory indicators suggest the patient may still be connected to the patient circuit, the controller may be configured to screen the determined loop disconnection event as false. If the respiratory indicators do not suggest the patient may still be connected to the patient circuit, the controller may be configured to screen the determined loop disconnection event as true. The respiratory indicators consist of one or more of the following: (i) expiratory flow rate indicating expiratory effort; (ii) inspiratory flow rate indicating inspiratory effort; (iii) the difference between an instantaneous disconnection parameter calculated from the inspiratory phase and an instantaneous parameter calculated from the expiratory phase; (iv) a comparison of the variance of the instantaneous disconnection parameter with a previous value of the instantaneous disconnection parameter; and (v) the change of the instantaneous disconnection parameter over time during the respiratory phase.

[0075] The controller can be further configured to compare the flow rate with a predetermined threshold to confirm the occurrence of a loop disconnection event after it has been detected. The controller can be further configured to detect reconnection of the patient circuit to the patient after a loop disconnection event has been detected. Reconnection of the patient circuit to the patient can be detected by comparing a transient disconnection parameter with a second threshold. Reconnection of the patient circuit to the patient can be detected by detecting abrupt changes in the transient disconnection parameter.

[0076] In some cases, a breathing device may include any one or more of the aforementioned systems, and may also include one or more sensors, as well as a pressure generator configured to supply a pressurized airflow.

[0077] Some embodiments of this technology may include a respiratory therapy system configured to provide respiratory therapy to a patient breathing during a continuous respiratory cycle including inspiratory and expiratory phases. The system may include a pressure generator configured to supply a pressurized airflow. The pressure generator may be configured to be coupled to a patient interface via an air circuit to deliver pressurized air from the pressure generator to the patient. The system may include at least one sensor configured to provide one or more signals indicative of pressure and flow rate of the pressurized airflow. The system may include a controller including a processor configured to repeatedly detect instantaneous pressure and flow rate values ​​based on one or more signals from the at least one sensor. The processor-included controller may be configured to repeatedly calculate instantaneous conductivity values ​​based on the instantaneous pressure and flow rate values. The processor-included controller may be configured to monitor changes in the instantaneous conductivity value over time to detect the occurrence of respiratory events within the system.

[0078] In some cases, a respiratory event can be an obstruction. Obstruction can be detected when the transient conductivity drops below a predetermined threshold. Obstruction can also be detected when the transient conductivity remains constant over time. Obstruction can occur in the air circuit, the patient interface, or the patient's airway.

[0079] In some cases, a respiratory event can be flow starvation during a volumetric target mode. Flow starvation can be detected as a distribution function of instantaneous conductivity values ​​over the inspiratory phase of the respiratory cycle. Flow starvation can be detected when the instantaneous conductivity values ​​are higher during the early to mid-inspiratory phase compared to the late inspiratory phase. Flow starvation can be detected by comparing (a) the instantaneous conductivity value calculated from the inspiratory phase of the respiratory cycle with (b) a conductivity threshold. Flow starvation can be detected when the instantaneous conductivity value calculated from the inspiratory phase of the respiratory cycle exceeds the conductivity threshold. In some cases, upon detecting a respiratory event, the controller can be configured to activate a message to indicate the occurrence of the respiratory event.

[0080] Some embodiments of this technology may include a respiratory therapy system configured to provide respiratory therapy to a patient breathing during a continuous respiratory cycle including inspiratory and expiratory phases. The system may include a pressure generator configured to supply a pressurized airflow. The pressure generator may be configured to be coupled to a patient interface via an air circuit to deliver pressurized air from the pressure generator to the patient. The system may include at least one sensor configured to provide one or more signals indicative of pressure and flow rate of the pressurized airflow. The system may include a controller including a processor configured to repeatedly detect instantaneous pressure and flow rate values ​​based on one or more signals from the at least one sensor. The system may include a controller including a processor configured to repeatedly calculate instantaneous conductivity values ​​based on the instantaneous pressure and flow rate values. The system may include a controller including a processor configured to monitor changes in the instantaneous conductivity value over time to monitor respiratory therapy.

[0081] In some configurations, the controller can determine the level of difference between the instantaneous conductance value calculated from the beginning of the inspiratory phase and the instantaneous conductance value calculated from the end of the inspiratory phase. The controller can be configured to adjust the rise time setpoint based on the level of difference. The controller can be configured to adjust the peak inspiratory flow setpoint based on the level of difference. The controller can be configured to monitor the instantaneous conductance value over time to determine the inspiratory and expiratory phases of one or more respiratory cycles. The controller can be configured to monitor the instantaneous conductance value over time to detect inadequate ventilation. The controller can be configured to detect inadequate ventilation as an abnormally low conductance value compared to a recent baseline conductance value.

[0082] Some embodiments of this technology may include a respiratory therapy system configured to provide respiratory therapy to a patient breathing during a continuous respiratory cycle including inspiratory and expiratory phases. The system may include a pressure generator configured to supply a pressurized airflow. The pressure generator may be configured to be coupled to a patient interface via an air circuit to deliver pressurized air from the pressure generator to the patient. The system may include at least one sensor configured to provide one or more signals indicative of pressure and flow rate of the pressurized airflow. The system may include a controller including a processor configured to repeatedly detect instantaneous pressure and flow rate values ​​based on one or more signals from the at least one sensor. The system may include a controller including a processor configured to repeatedly calculate instantaneous impedance values ​​based on the instantaneous pressure and flow rate values. The system may include a controller including a processor configured to monitor changes in the instantaneous impedance values ​​over time to detect the occurrence of respiratory events within the system.

[0083] In some models, a breathing event can be an obstruction. An obstruction can be detected when the transient impedance exceeds a predetermined threshold. An obstruction can also be detected when the transient impedance remains substantially constant over time. Obstructions can occur in the air circuit, the patient interface, or the patient's airway.

[0084] In some models, a respiratory event can be flow starvation during a volume target mode. Flow starvation can be detected as a distribution function of instantaneous impedance values ​​over the inspiratory portion of the respiratory cycle. Flow starvation can be detected when the instantaneous impedance values ​​are lower during the early to mid-inspiratory phase compared to the late inspiratory phase. Flow starvation can be detected by comparing the instantaneous impedance values ​​calculated from the inspiratory phase of the respiratory cycle with an impedance threshold. Flow starvation can be detected when the instantaneous impedance values ​​calculated from the inspiratory phase of the respiratory cycle are lower than the impedance threshold.

[0085] In some cases, when a respiratory event is detected, the controller can be configured to provide a message to indicate that a respiratory event has occurred.

[0086] Some embodiments of this technology may include a respiratory therapy system configured to provide respiratory therapy to a patient breathing during a continuous respiratory cycle including inspiratory and expiratory phases. The system may include a pressure generator configured to supply a pressurized airflow. The pressure generator may be configured to be coupled to a patient interface via an air circuit to deliver pressurized air from the pressure generator to the patient. The system may include at least one sensor configured to provide one or more signals indicative of pressure and flow rate of the pressurized airflow. The system may include a controller including a processor configured to repeatedly detect instantaneous pressure and flow rate values ​​based on one or more signals from the at least one sensor. The system may include a controller including a processor configured to repeatedly calculate instantaneous impedance values ​​based on the instantaneous pressure and flow rate values. The system may include a controller including a processor configured to monitor changes in the instantaneous impedance value over time to monitor respiratory therapy.

[0087] In some models, the controller determines the level of difference between the instantaneous impedance value calculated from the beginning of the inspiratory phase and the instantaneous impedance value calculated from the end of the inspiratory phase. The controller can be configured to adjust the rise time setpoint based on the level of difference. The controller can be configured to adjust the peak inspiratory flow setpoint based on the level of difference. The controller can be configured to monitor instantaneous impedance values ​​over time to determine the inspiratory and expiratory phases of each respiratory cycle. The controller can be configured to monitor instantaneous impedance values ​​over time to detect inadequate ventilation. The controller can be configured to detect inadequate ventilation as an impedance value that is abnormally high compared to a recent reference impedance value.

[0088] One form of this technology includes a method and apparatus for detecting patient circuit disconnection based on the determination of transient impedance in the breathing circuit. The transient impedance can be compared with an impedance threshold or with an impedance profile (shape) consistent with a passive, disconnected circuit. The impedance threshold can be determined based on the patient circuit coupled to the device.

[0089] One form of this technology includes a method and apparatus for detecting patient circuit disconnection based on the determination of transient conductance in the breathing circuit. The transient conductance can be compared with a conductance threshold or a conductance distribution map (shape). The conductance threshold can be determined based on the patient circuit coupled to the device.

[0090] Another aspect of this technology is a method for detecting the occurrence of a loop disconnection event in a respiratory device configured to provide respiratory therapy to a patient via a patient circuit. The method includes determining the type of patient circuit configuration coupled to the respiratory device; determining a disconnection setpoint based on the type of patient circuit configuration; repeatedly determining pressure and flow parameters in the controller of the respiratory device, and determining an instantaneous disconnection parameter based on the pressure and flow parameters; and determining the occurrence of a loop disconnection event based on a change in the disconnection setpoint using the instantaneous disconnection parameter. In some forms, the disconnection setpoint and the instantaneous disconnection parameter may be conductivity values. In other forms, the disconnection setpoint and the instantaneous disconnection parameter may be impedance values.

[0091] Another aspect of this technology is a method for detecting the occurrence of a circuit break in a respiratory device configured to provide respiratory therapy to a patient via a patient circuit. The method includes: repeatedly determining pressure and flow parameters in a controller of the respiratory device, and repeatedly determining transient break parameters based on the pressure and flow parameters; comparing consecutive transient break parameters to determine the level of variability of the transient break parameters over time, and determining the occurrence of a circuit break based on the level of variability. The transient break parameter may be a conductivity value or an impedance value.

[0092] Another aspect of this technology is a loop disconnection system for detecting the occurrence of a loop disconnection event in a respiratory device. The system includes: a controller having at least one processor to access data representing pressure and flow parameters of a breathable gas; the controller being configured to determine a type of patient circuit configuration coupled to the respiratory device; determine a disconnection setpoint based on the type of patient circuit configuration; determine an instantaneous disconnection parameter based on the pressure and flow parameters; determine the occurrence of a loop disconnection event based on a change in the disconnection setpoint using the instantaneous disconnection parameter; and indicate the occurrence of the loop disconnection event. In some forms, the disconnection setpoint and the instantaneous disconnection parameter may be conductivity values. In other forms, the disconnection setpoint and the instantaneous disconnection parameter may be impedance values.

[0093] In some forms, a disconnection detection system or method may include a disconnection setpoint as a first disconnection threshold, and compare a determined instantaneous disconnection parameter with the first disconnection threshold to determine the occurrence of a loop disconnection event.

[0094] In other forms of disconnection detection systems or methods, the disconnection setpoint is a distribution pattern shape, and the occurrence of a loop disconnection event involves comparing multiple determined instantaneous disconnection parameters with the distribution pattern shape to determine the occurrence of a loop disconnection.

[0095] In some forms of disconnection detection systems or methods, patient-specific information can be entered into the respiratory device, and this patient-specific information can be used to determine the disconnection setting. Patient-specific information may include one or more of the patient's age, weight, height, or patient type.

[0096] In some forms of disconnection detection systems or methods, the disconnection setpoint can be determined based on a lookup table stored in the memory of the respiratory device.

[0097] In some forms of disconnection detection systems or methods, the type of patient circuit configuration can be automatically detected by the respiratory device. However, in other forms, the type of patient circuit configuration can be input into the respiratory device via a user interface. The type of patient circuit configuration can be identified as at least one of invasive, non-invasive, ventilated, non-ventilated, single-branch, or dual-branch.

[0098] In some forms of disconnection detection systems or methods, an indication of the loop connection status is provided on the user interface of the respiratory device. A disconnection indication can be provided when a loop disconnection event is detected. The disconnection indication may include providing a message on the respiratory device or activating a disconnection alarm. In some forms, the disconnection alarm can be muted for a predetermined period of time via the respiratory device's user interface. In some forms, the disconnection indication must be provided continuously for a predetermined time before the disconnection alarm is activated. The predetermined time may be a set time between 5 and 60 seconds or a predetermined number of breaths. The predetermined time may be adjustable.

[0099] In some forms of disconnection detection systems or methods, the transient disconnection parameter is determined at least once per breath. For example, the transient disconnection parameter is determined during the inspiratory phase of each breath, or it is determined at least once during the inspiratory phase and at least once during the expiratory phase of each breath. In other forms, the transient disconnection parameter can be determined at predetermined time intervals.

[0100] In some forms of disconnection detection systems or methods, a sensitivity setting is determined to adjust the sensitivity of the disconnection setting. The sensitivity setting can be determined as a default sensitivity setting based on the type of patient circuit configuration. The sensitivity setting can be determined during a testing phase, which can occur before or while the ventilator is providing respiratory therapy to the patient. During the testing phase, activation of the disconnection alarm can be disabled.

[0101] In some forms, the sensitivity setting can be selected from a predetermined range of settings via a user interface. The predetermined range of settings can include values ​​between 1% and 100%. For example, the predetermined range of settings can include values ​​provided in 5% increments between 5% and 95%.

[0102] In some forms, a sensitivity setting indicator can be provided on the display of the breathing device, which can indicate whether a disconnection event has been detected at the determined sensitivity setting.

[0103] In some forms following the detection of a circuit disconnection event, the disconnection detection system or method may monitor respiratory indicators that indicate the patient is still connected to the patient circuit to identify the disconnection event. For example, if the respiratory indicators do indicate that the patient is still connected to the patient circuit, the occurrence of the circuit disconnection event can be identified as false, thereby disqualifying it as a circuit disconnection event. Alternatively, if the respiratory indicators do not indicate that the patient is still connected to the patient circuit, the occurrence of the circuit disconnection event can be identified as true, thereby confirming the circuit disconnection event. The respiratory indicators may include one or more of the following: (i) detecting expiratory flow rate indicating expiration; (ii) detecting inspiratory flow rate indicating inspiration; (iii) the difference between an instantaneous disconnection parameter determined during the inspiration phase and an instantaneous parameter determined during the expiration phase; (iv) a comparison of the variance of the instantaneous disconnection parameter with a previously measured value of the instantaneous disconnection parameter; or (v) the change of the instantaneous disconnection parameter over time during the respiratory phase.

[0104] In some forms following the detection of a loop break event, the break detection system or method can compare the determined flow parameters with a predetermined threshold to confirm the occurrence of the loop break event.

[0105] In some forms following the detection of a circuit break event, a disconnection detection system or method can detect the reconnection of the patient circuit to the patient. Reconnection can be detected by comparing a transient disconnection parameter to a second threshold. Alternatively, it can be detected by detecting abrupt changes in the transient disconnection parameter.

[0106] Another aspect of this technology is a breathing device that includes a circuit disconnection system or a method for detecting circuit disconnection events.

[0107] Another aspect of this technology is a respiratory system configured to provide respiratory therapy to a patient breathing in a continuous respiratory cycle including an inspiratory phase and an expiratory phase. The system includes a pressure generator configured to supply pressurized gas; at least one sensor to provide signals indicating the pressure and flow rate of the pressurized gas; a patient engagement device coupled to an air delivery circuit to deliver pressurized gas from the pressure generator to the patient; and a controller including a processor configured to repeatedly determine instantaneous pressure and flow rate values ​​and to determine instantaneous conductivity values ​​based on the instantaneous pressure and flow rate values, wherein the controller monitors changes in the instantaneous conductivity values ​​over time to determine the occurrence of respiratory events within the system.

[0108] In some forms, a respiratory event is an obstructive event. An obstructive event can be detected when the transient conductance drops below a predetermined threshold. In some forms, obstruction is detected when the transient conductance remains constant over time. Obstructive events can occur in the patient circuit or the patient airway.

[0109] In other forms, a respiratory event is a flow starvation event that occurs during the volume target mode. A flow starvation event can be detected as a distribution function of instantaneous conductance values ​​during the inspiratory phase of the respiratory cycle. A flow starvation event can be detected when the instantaneous conductance values ​​during the early to mid-inspiratory phase are higher than those at the end of the inspiratory phase. A flow starvation event can be detected by comparing the instantaneous conductance value determined during the inspiratory phase of the respiratory cycle with a third conductance threshold. A flow starvation event can be detected when the instantaneous conductance value determined during the inspiratory phase of the respiratory cycle exceeds the third conductance threshold.

[0110] In some forms, the respiratory system controller can be configured to provide messages to indicate the occurrence of respiratory events.

[0111] Another aspect of this technology is a respiratory system configured to provide respiratory therapy to a patient breathing in a continuous respiratory cycle including an inspiratory phase and an expiratory phase. The system includes a pressure generator configured to supply pressurized gas; at least one sensor to provide signals indicating the pressure and flow rate of the pressurized gas; a patient engagement device coupled to an air delivery circuit to deliver pressurized gas from the pressure generator to the patient; and a controller including a processor configured to repeatedly determine instantaneous pressure and flow rate values ​​and determine instantaneous conductivity values ​​based on the instantaneous pressure and flow rate values, wherein the controller monitors changes in the instantaneous conductivity values ​​over time to monitor the therapy.

[0112] The controller can determine the level of difference between an instantaneous conductivity value determined at the beginning of the inspiratory phase and an instantaneous conductivity value determined at the end of the inspiratory phase. The controller can be configured to adjust the rise time setpoint or the peak inspiratory flow rate setpoint based on the level of difference.

[0113] In some forms, the controller can monitor instantaneous conductance values ​​over time to determine the inspiratory and expiratory phases of each respiratory cycle of the patient.

[0114] Another aspect of this technology is a respiratory therapy system configured to provide respiratory therapy to a patient breathing in a continuous respiratory cycle including an inspiratory phase and an expiratory phase. The system includes: a pressure generator configured to supply pressurized gas; at least one sensor to provide signals indicating the pressure and flow rate of the pressurized gas; a patient engagement device coupled to an air delivery circuit to deliver pressurized gas from the pressure generator to the patient; and a controller including a processor configured to repeatedly determine instantaneous pressure and flow rate values ​​and determine instantaneous impedance values ​​based on the instantaneous pressure and flow rate values, wherein the controller monitors changes in the instantaneous impedance values ​​over time to determine the occurrence of respiratory events within the system.

[0115] In some forms, a respiratory event is an obstructive event. An obstructive event can be detected when the transient impedance exceeds a predetermined threshold. An obstructive event can also be detected when the transient impedance remains substantially constant over time. Obstructive events can occur in the patient circuit or the patient airway.

[0116] In some forms, a respiratory event is a flow starvation event that occurs during the volume target mode. A flow starvation event can be detected as a distribution function of instantaneous impedance values ​​over the inspiratory phase of the respiratory cycle. A flow starvation event can be detected when the instantaneous impedance value during the early to mid-inspiratory phase is lower than that at the end of the inspiratory phase. A flow starvation event can be detected by comparing the instantaneous impedance value determined during the inspiratory phase of the respiratory cycle with a third impedance threshold. A flow starvation event can be detected when the instantaneous impedance value determined during the inspiratory phase of the respiratory cycle is lower than the third impedance threshold. In some forms, the controller can be configured to provide a message indicating the occurrence of a respiratory event.

[0117] Another aspect of this technology is a respiratory system configured to provide respiratory therapy to a patient breathing in a continuous respiratory cycle including an inspiratory phase and an expiratory phase. The system includes a pressure generator configured to supply pressurized gas; at least one sensor to provide signals indicating the pressure and flow rate of the pressurized gas; a patient engagement device coupled to an air delivery circuit to deliver pressurized gas from the pressure generator to the patient; and a controller including a processor configured to repeatedly determine instantaneous pressure and flow rate values ​​and determine instantaneous impedance values ​​based on the instantaneous pressure and flow rate values, wherein the controller monitors changes in the instantaneous impedance values ​​over time to monitor the therapy.

[0118] In some forms, the controller can determine the level of difference between an instantaneous impedance value determined at the beginning of the inspiratory phase and an instantaneous impedance value determined at the end of the inspiratory phase. The controller can be configured to adjust a rise time setpoint or a peak inspiratory flow rate setpoint based on the level of difference. The controller can monitor the instantaneous impedance value over time to determine the inspiratory and expiratory phases of each respiratory cycle for the patient.

[0119] One aspect of this technology is a method for detecting the reconnection of the patient circuit to the breathing equipment.

[0120] Of course, some of these aspects can form sub-aspects of this technology. Sub-aspects and / or aspects of the aspects can be combined in various ways and also constitute other aspects or sub-aspects of this technology.

[0121] The methods, systems, apparatus, and devices described herein for loop disconnection detection can provide improved functionality in processors, such as processors in dedicated computers, and / or monitoring devices for respiratory equipment. Furthermore, in some cases, they can be integrated into the controller or processor of therapeutic devices, such as respiratory pressure therapy devices. Moreover, the described methods, systems, apparatus, and devices can provide improvements in the field of automated monitoring and / or respiratory equipment for respiratory systems or conditions, including, for example, sleep-disordered breathing, pediatric respiratory therapy, or respiratory insufficiency (e.g., COPD), by enabling loop disconnection detection, making it easier to identify potentially problematic or dangerous respiratory-related disconnection events.

[0122] Other features of the present technology will become apparent from the information contained in the following detailed description, abstract, drawings and claims. Attached Figure Description

[0123] This technology is illustrated by way of example and not limitation in the figures, and similar reference numerals in the figures refer to similar elements, including:

[0124] Treatment System

[0125] Figure 1A A system is shown in which a patient 1000 wearing a patient interface 3000 via a nose pillow receives a positive-pressure air supply from an RPT device 4000. The air from the RPT device 4000 is humidified in a humidifier 5000 and delivered to the patient 1000 along an air circuit 4170. A bed companion 1100 is also shown.

[0126] Figure 1BA system is shown in which a patient 1000 wearing a patient interface 3000 in the form of a nasal mask receives a positive pressure air supply from an RPT device 4000. The air from the RPT device is humidified in a humidifier 5000 and delivered to the patient 1000 along an air circuit 4170.

[0127] Figure 1C A system is shown in which a patient 1000 wearing a patient interface 3000 in a full-face mask receives a positive-pressure air supply from an RPT device 4000. The air from the RPT device is humidified in a humidifier 5000 and delivered to the patient 1000 along an air circuit 4170.

[0128] Respiratory system and facial anatomy

[0129] Figure 2A A schematic diagram of the human respiratory system is shown, including the nasal cavity and oral cavity, larynx, vocal cords, esophagus, trachea, bronchi, lungs, alveolar sacs, heart, and diaphragm.

[0130] Figure 2B This diagram shows a view of the human upper airway, including the nasal cavity, nasal bones, external nasal cartilages, greater alar cartilages, nostrils, upper lip, lower lip, larynx, hard palate, soft palate, oropharynx, tongue, epiglottis, vocal cords, esophagus, and trachea.

[0131] Patient Interface

[0132] Figure 3A A patient interface in the form of a nasal mask according to the present technology is shown.

[0133] RPT device

[0134] Figure 4A A perspective view of an RPT device in the form of a ventilator according to the present technology is shown.

[0135] Figure 4B yes Figure 4A Front view of a ventilator device.

[0136] Figure 4C yes Figure 4A Rear view of the ventilator device.

[0137] Figure 4D yes Figure 4A Bottom view of the ventilator device.

[0138] Figure 4E A schematic diagram of the arrangement of internal components in a ventilator according to one aspect of the present technology is shown.

[0139] Figure 4F A schematic diagram of the interior of a pneumatic block according to one aspect of the present technology is shown.

[0140] Figure 4G A schematic diagram of the pneumatic circuit of one form of the device according to the present technology is shown. The upstream and downstream directions are indicated.

[0141] Figure 4H A schematic diagram of the electrical components of an apparatus according to one aspect of the present technology is shown.

[0142] Figure 4I A schematic diagram of an algorithm implemented in an apparatus according to one aspect of the present technology is shown. In this figure, solid arrows indicate the actual information flow (e.g., via electronic signals).

[0143] Humidifier

[0144] Figure 5A This is an isometric view of one form of humidifier according to the present technology.

[0145] Figure 5B An isometric view of one form of humidifier according to the present technology is shown, which shows the humidifier reservoir 5110 removed from the humidifier reservoir dock 5130.

[0146] Figure 5C A schematic diagram of one form of humidifier according to the present technology is shown.

[0147] respiratory waveform

[0148] Figure 6A A model of a typical breathing waveform during sleep is shown.

[0149] Figure 6B The image shows the patient's normal breathing over approximately ninety seconds during non-REM sleep.

[0150] Fault detection

[0151] Figure 7A This is a flowchart of a loop disconnection detection method according to one aspect of this technology.

[0152] Figure 7B This is a flowchart of a loop disconnection detection method according to another aspect of this technology.

[0153] Figure 7C The recording lines show the changes in instantaneous conductivity, pressure, and flow rate over time relative to the conductivity threshold at 45% sensitivity setting.

[0154] Figure 7D The recording lines show the changes in instantaneous conductivity, pressure, and flow rate over time relative to the conductivity threshold at 20% sensitivity setting.

[0155] Figure 7EThe recording lines show the changes in instantaneous conductivity, pressure, and flow rate over time relative to the conductivity threshold at 15% sensitivity setting.

[0156] Figures 7F(i) and (ii) show the recording lines of respiratory flow and airway pressure over time, as well as the recording lines of instantaneous conductivity and conductivity change over time.

[0157] Figures 7G(i) and (ii) show the recording lines of respiratory flow and instantaneous conductance, which indicate the conductance trigger threshold.

[0158] Figures 7H(i) and (ii) show the recording lines of respiratory flow and airway pressure over time, and the recording lines of transient conductivity and transient impedance over time, respectively, indicating a patient circuit disconnection.

[0159] Figure 7I The graph shows the instantaneous conductance over time for pediatric patients in the case of a endotracheal tube with a dual-branch valve. Detailed Implementation

[0160] Before describing this technology in further detail, it should be understood that this technology is not limited to the specific instances described herein, and the specific instances described herein may be modified. It should also be understood that the terminology used in this disclosure is for the purpose of describing the specific instances described herein only and is not intended to be limiting.

[0161] The following description relates to various instances that may share one or more common features and / or characteristics. It should be understood that one or more features of any instance may be combined with one or more features of another instance or other instances. Furthermore, in any instance, any single feature or combination of features may constitute another instance.

[0162] treat

[0163] In one form, the technology includes a method for treating respiratory distress, the method comprising the step of applying positive pressure to the airway inlet of a patient 1000.

[0164] In some instances of this technique, positive pressure air is supplied to the patient’s nasal passages through one or both nostrils.

[0165] Treatment System

[0166] In one form, the technology includes a respiratory device or apparatus for treating respiratory disorders. The respiratory device or apparatus may include an RPT (Respiratory Pressure Test) device 4000 for supplying pressurized air to a patient 1000 via an air circuit 4170 leading to a patient interface 3000.

[0167] Patient Interface

[0168] According to one aspect of the present technology, the noninvasive patient interface 3000 includes the following functional aspects: a seal-forming structure 3100, an inflation chamber 3200, a positioning and stabilizing structure 3300, an air vent 3400, a connection port 3600 for connection to an air circuit 4170, and a forehead support 3700. In some forms, the functional aspects may be provided by one or more physical components. In some forms, a single physical component may provide one or more functional aspects. In use, the seal-forming structure 3100 is arranged around the inlet of the patient's airway to facilitate the supply of positive pressure air to the airway.

[0169] Sealing Formation Structure

[0170] In one form of this technology, the sealing forming structure 3100 provides a sealing forming surface and may additionally provide a cushioning function.

[0171] The sealing structure 3100 according to this technology can be configured from a soft, flexible and resilient material such as silicone.

[0172] In one embodiment, the sealing portion of the non-invasive patient interface 3000 includes a pair of nasal sprays or nasal pillows, each configured and arranged to form a seal with the corresponding nostril of the patient's nose.

[0173] In one embodiment, the non-invasive patient interface 3000 includes a sealing forming portion that, during use, forms a seal on the upper lip region (i.e., the upper lip) of the patient's face.

[0174] In one embodiment, the non-invasive patient interface 3000 includes a sealing forming portion that forms a seal on the chin region of the patient's face during use.

[0175] Positioning and stabilizing structure

[0176] The sealing structure 3100 of the patient interface 3000 of this technology can be kept in a sealed state during use by positioning and stabilizing structure 3300.

[0177] In one form of this technology, a positioning and stabilization structure 3300 is provided, configured in a manner consistent with that worn by a patient while sleeping. In one instance, the positioning and stabilization structure 3300 has a small side or cross-sectional thickness to reduce the sensing or physical volume of the patient interface. In one instance, the positioning and stabilization structure 3300 includes at least one strap with a rectangular cross-section. In one instance, the positioning and stabilization structure 3300 includes at least one flat strap.

[0178] In one form of this technology, the positioning and stabilizing structure 3300 includes a strap configured as a laminate of a fabric patient contact layer, a foam inner layer, and a fabric outer layer. In one form, the foam is porous to allow moisture (e.g., sweat) to pass through the strap. In another form, the fabric outer layer includes a loop material for engagement with a hook material portion.

[0179] In some forms of this technology, the positioning and stabilizing structure 3300 includes a strap that is extendable, for example, elastically extendable. For example, the strap may be configured to be taut during use and to guide forces to create a sealed contact between the pad and a portion of the patient's face. In one instance, the strap may be configured as a tie.

[0180] In some forms of this technology, the positioning and stabilizing structure 3300 includes a strap that is flexible and, for example, non-rigid. An advantage of this is that the strap makes it more comfortable for the patient to lie on it while sleeping.

[0181] Vent

[0182] In one form, the patient interface 3000 includes a ventilation port 3400 constructed and arranged to allow flushing of exhaled gases such as carbon dioxide.

[0183] One form of the vent 3400 according to the present technology includes a plurality of holes, for example, about 20 to about 80 holes, or about 40 to about 60 holes, or about 45 to about 55 holes.

[0184] The vent 3400 may be located in the inflation chamber 3200. Alternatively, the vent 3400 may be located in a decoupling structure, such as a rotating shaft.

[0185] Decoupling structure

[0186] In one form, the patient interface 3000 includes at least one decoupling structure, such as a swivel or a ball-and-socket joint.

[0187] Connection port

[0188] Connection port 3600 allows connection to air circuit 4170.

[0189] Forehead brace

[0190] In one configuration, the patient interface 3000 includes a forehead support 3700.

[0191] Anti-asphyxiation valve

[0192] In one configuration, the patient interface 3000 includes an anti-asphyxiation valve.

[0193] port

[0194] In one embodiment of this technology, the patient interface 3000 includes one or more ports that allow access to the volume within the inflation chamber 3200. In one embodiment, this allows a clinician to supply supplemental oxygen. In one embodiment, this allows for direct measurement of the properties of the gas within the inflation chamber 3200, such as pressure.

[0195] RPT device

[0196] According to one aspect of the present technology, the RPT device 4000 includes mechanical and pneumatic components, electrical components, and is configured to execute one or more algorithms.

[0197] An RPT device or ventilator 4000 according to this technology is shown in... Figures 4A to 4E The RPT device 4000 includes a housing 4012, an exhaled air inlet port 4014, and an inhaled air outlet port 4016. The air inlet port 4014 and the air outlet port 4016 can be connected to an air delivery tube (not shown) that can be inserted into a patient's trachea, coupled to a mask or nasal mask fitted to the patient's nose or mouth, or otherwise attached to the patient to assist breathing. The housing 4012 for the RPT device 4000 can be portable and includes a handle 4018 for carrying the ventilator. The housing may have an upper housing shell 4020, a chassis 4021, and a lower housing shell 4022 coupled together to form the outer surface of the RPT device. However, it should be understood that the housing may have other configurations, such as including only two components with an upper shell and a lower shell, or may have more than three components. RPT devices may include a ventilator or aspects of a ventilator as described in U.S. Patent Application No. 13 / 624,167, filed September 21, 2012 and disclosed as U.S. 2013 / 0263854 and incorporated herein in its entirety.

[0198] The chassis 4021 can provide a structural framework for the ventilator assembly. The chassis 4021 can be configured to receive the inlet filter assembly 4036 and the inlet seal 4038, which are described in more detail below, respectively. The inlet seal 4038 is also configured to be coupled to the inlet of the pneumatic block module 4056. Preferably, the inlet seal 4038 is formed of a compliant material such as silicone resin, and the inlet seal can be overmolded onto the inlet of the pneumatic block module 4056.

[0199] The chassis 4021 may also include a pneumatic block base in which the pneumatic block module 4056 is located to facilitate alignment and assembly of the pneumatic block module 4056 within the housing. The chassis 4021 may also include a portion of a handle 4018.

[0200] The rear of the chassis 4021 may include a series of interfaces for various connectors and switches on the rear panel. For example, interfaces for electrical connector 4049, switch 4051, data connector 4047, and oxygen connector or inlet port 4046.

[0201] The base 4021 may also provide multiple interfaces for positioning and holding components of the RPT device 4000, such as the cooling fan 4068, the printed circuit board (PCB) 4086, and components of the exhalation section 4031 positioned adjacent to the exhalation air port 4014 (see [link]). Figure 4E ).

[0202] The expiratory section 4031 of the ventilator 4000 is configured to allow insertion of an expiratory interface module to receive exhaled air from the patient via the exhaled air inlet port 4014. Different expiratory interface modules may include an expiratory valve and an expiratory adapter.

[0203] like Figures 4A to 4E As seen, the RPT device 4000 may include a battery compartment to locate and engage with a removable internal battery 4450. A removable battery cover 4052 is disposed on the outer bottom surface of the lower housing 4022 to allow access for battery insertion or removal. A removable exhalation mask 4048, oxygen sensor cover 4054, and grille 4044 may also be disposed on the outer bottom surface to allow heat dissipation from the components, such as... Figure 4D As shown. The lower housing 4022 may also include anti-slip feet or gripping surfaces or one or more anti-slip or gripping feet 4053 (such as thermoplastic polyurethane (TPU) feet) on its outer bottom surface to prevent the RPT device 4000 from slipping off smooth surfaces. The anti-slip or gripping feet 4053 may also raise the RPT device 4000 to prevent spilled water from accumulating below the bottom of the RPT device. A portion of the handle 4018 is also located within the lower housing 4022.

[0204] like Figure 4AAs shown, the upper housing 4020 provides the top surface of the RPT device 4000 and is configured to receive a user interface display device 4024. The housing may include a computer or processor-driven user interface display device 4024, such as a liquid crystal display (LCD) adapted to receive touch input from a computer. The display device may be flush with the top surface of the housing for easy visibility when the RPT device is in use. An alarm indicator light bar 4026, such as a light-emitting diode (LED) light bar, and a button 4028 for disabling audio or visual alarms may be adjacent to the display. However, it should be understood that other known user interface systems, such as screens, buttons, dials, keys, or combinations thereof, may be used. The base 4021, the lower housing 4022, and the upper housing 4020 are coupled together to assemble the complete housing 4012. Fasteners such as screws may be used to assemble the housing 4012, but any other known fasteners may also be used. A chassis 4021 is assembled between the upper housing 4020 and the lower housing 4022.

[0205] like Figure 4C As shown, the rear portion of housing 4012 may include a filter assembly 4036. Air to be pumped into the patient's lungs is drawn into an air inlet associated with the filter assembly. The air passes through a permeable filter membrane in the filter and enters an air passage for directing airflow to the patient.

[0206] The rear portion of the housing may include a data connection 4047 for communicating with digital devices such as computer networks, alarm systems, pulse oximeters (e.g., spO2), and digital recording media. A power connection 4049 and an on / off switch 4051 may also be located at the rear portion of the housing. An input grille 4044-I may provide an air inlet to cool components and allow heat generated by the operation of internal components (e.g., the blower motor and CPU). The movement of heated air through the internal components can be driven by a cooling fan 4068 within the housing, which may be located near the heated air output grille 4044-O (in...). Figure 4D (As shown in the diagram, it is located on the bottom of the housing). Additionally, an oxygen (O2) inlet port 4046 may be located at the rear of the housing, allowing connection to an oxygen source.

[0207] Figure 4DThe bottom of the RPT device 4000 is shown. A removable exhalation mask 4048, acting as an external inlet, provides access to and protection of the compartment for the exhalation portion or segment of the housing. Removing the exhalation mask 4048 provides access to any inserted exhalation guide module and the exhaled air inlet port 4014. It also allows for easy removal and replacement of exhalation guide modules, such as exhalation valves or exhalation adapters. The exhalation mask 4048 can be secured to the housing 4012 to reduce excessive play caused by a latch 4050 that can be turned by fingers. Optionally, in some embodiments, the latch can be used to lock the latch to prevent release. An optional latch release button 4050R can be operated to disengage the exhalation mask. The release button 4050R can be pressed down to unlock the exhalation mask 4048. Those skilled in the art will understand that alternative methods of removably securing and coupling the exhalation mask 4048 to the housing can also be utilized. The bottom of the housing may also have a removable battery cover 4052 for a replaceable internal battery and an oxygen sensor cover 4054 that can be removed to access the oxygen sensor 4064.

[0208] Figure 4E The internal components of an RPT device 4000 according to one aspect of the present technology are shown. The RPT device 4000 may include some or all of the following components: an inlet air filter 4034, an inlet seal 4038, an inlet silencer 4039, an oxygen supply path 4043, a pneumatic block module 4056, an inhalation section 4033, a safety valve 4085, an exhalation section 4031, a controller and PCB 4086, a cooling fan 4068, and an internal battery 4450.

[0209] A pneumatic block module 4056 is arranged within the RPT device 4000 such that its air passages are aligned with the filter assembly 4036 at the air inlet, inhalation outlet port 4016, and optional oxygen supply path 4043. Arrows indicate the paths of the airflow 4035 and oxygen flow 4045 through the ventilator 4000, respectively. The airflow 4035 enters via the inlet air filter 4034 and travels through the filter assembly 4036 and inlet seal 4038 to the inlet silencer 4039 of the pneumatic block module 4056. Optionally, an oxygen source can be connected to the oxygen inlet port 4046, and the oxygen flow 4045 is directed through the oxygen supply path 4043 and oxygen seal into the pneumatic block module 4056, where it merges with the inlet airflow 4035 within the inlet silencer 4039. Within the pneumatic block module 4056, the airflow 4035 is pressurized by the main blower 4104 (see...). Figure 4F Pressurized air flow 4035 and oxygen flow 4045 are directed out of pneumatic block module 4056 via outlet silencer 4084 and enter intake section 4033 through main seal 4040, and then flow out from intake outlet port 4016 to be delivered to patient interface (not shown) via air circuit (not shown).

[0210] An oxygen sensor 4064, located in the oxygen sensor compartment of the inspiratory section 4033, measures the amount of oxygen delivered to the patient. The oxygen sensor 4064 can be mounted in the housing 4012, allowing for easy replacement, and is adjacent to the inspiratory outlet port 4016. The oxygen sensor detects the oxygen level of the air pumped to the patient. Data from the oxygen sensor can be used to trigger an oxygen concentration-related alarm and provide data to a microprocessor to display the oxygen concentration on a user interface. The amount of oxygen supplied can be controlled by adjusting the known amount of air and oxygen supplied to the patient. However, the oxygen sensor can also optionally be used to regulate the amount of supplemental oxygen supplied through the oxygen inlet port 4046.

[0211] The oxygen sensor cover 4054 on the bottom of the housing (e.g.) Figure 4D (As shown) is removable to provide access to the oxygen sensor housed within the oxygen sensor compartment of the housing. The oxygen sensor is fitted into a mounting within the housing and is adjacent to the inspiratory outlet port 4016. A portion of the air flowing through the inspiratory outlet port 4016 is sensed by the oxygen sensor. The sensor generates a data signal indicating the oxygen level of the gas. The data is transmitted to a data connector, which in turn transmits the data to a processor. The processor analyzes the data to determine the amount of supplemental oxygen to be added to the air pumped to the patient.

[0212] The oxygen source can be either low-pressure or high-pressure. To supply high-pressure oxygen, an oxygen regulator (not shown) may be located within the oxygen supply path 4043 to reduce the pressure from the high-pressure oxygen source before the oxygen enters the inlet silencer 4039. The oxygen inlet port 4046 may be adapted to couple to a range of different oxygen connection adapters to allow for the connection of different types of oxygen connectors used in various jurisdictions, including but not limited to male or female diameter index safety systems (DISS), cannula indexing systems (SIS), the National Institute of Standards and Technology (NIST), and the French Association for Standardization (AFNOR).

[0213] In alternative arrangements (not shown), a high-pressure oxygen source may be located after the main blower 4104, such as within the outlet silencer 4084, where it is mixed with pressurized air. In some instances, high-pressure oxygen may be used to provide a pressure source for gas flow to the patient. In some arrangements, low-pressure oxygen may optionally be provided to the air circuit 4170 or the patient interface 3000.

[0214] Although the pneumatic block module 4056 is schematically shown as a rectangular shape, it should be understood that the pneumatic block module 4056 can have any shape, including an asymmetrical shape that conforms to the base in the housing and minimizes the possibility of the pneumatic block module 4056 being improperly inserted into the housing.

[0215] The main printed circuit board (PCB) 4086 can be assembled and mounted to the chassis 4021 and located between the chassis 4021 and the lower housing 4022. The main board's electronics may include a processor, electrical connectors for transmitting data signals from the pneumatic block module 4056, and power and data connectors for a blower, such as those for supplying pressurized air to the intake outlet port 4016. In this respect, the electrical connectors provide power and signal paths between the electronics on the PCB in the pneumatic block module 4056 and the electronics on the main PCB in the housing. The main board's electronics may also include data and power connectors for any sensors, such as the oxygen sensor 4064. The electronics in the housing can control the generation of images for the display device, sound signals for the speaker 4061 (such as for generating an audible alarm), detect signals from the pressure and oxygen sensors, and control the blower's rotational speed. The RPT device 4000 may optionally include a clock connected to the PCB 4086.

[0216] Figure 4F This is a schematic diagram of the internal components of the pneumatic block module 4056. The pneumatic block module 4056 includes a main blower 4104 with a volute assembly 4108, an inlet check valve assembly 4114, an optional oxygen inlet port 4144, a positive end-expiratory pressure (PEEP) blower 4124, an outlet silencer 4084, a safety valve 4085, a pressure sensor 4128, a flow sensor 4130 and a flow element 4132, and a PEEP pressure sensor 4142. The volute assembly 4108 forms most of the air path and performs some of the key functions of the pneumatic block module 4056.

[0217] Pneumatic block 4056 may include solenoid valve 4116 and flow control solenoid valve 4120, both configured to communicate with and control check valve assembly 4114. PEEP solenoid valve 4136 is configured to communicate with PEEP blower 4124 to control the pressure supply from PEEP blower 4124 to exhalation section 4031. A PEEP pressure line is coupled between the PEEP exhalation valve and the PEEP supply port in exhalation section 4031 to provide a PEEP pressure source. PEEP pressure sensor 4142 senses the PEEP pressure.

[0218] Figure 4GA schematic arrangement of another form of the RPT device 4000 is shown. The pneumatic path of the RPT device 4000 preferably includes an inlet air filter 4034, an inlet silencer 4039, a controllable source (pressure generator) 4140 (preferably, a main blower 4104) capable of supplying air at positive pressure, and an outlet silencer 4084. The pneumatic path includes one or more transducers 4270, such as a pressure sensor 4128 and a flow sensor 4130.

[0219] The preferred pneumatic block 4056 includes a portion of the pneumatic path located within the outer housing 4012.

[0220] The RPT device 4000 preferably includes a power supply 4210, one or more input devices 4220, a central controller 4230, a treatment device controller 4240, one or more protection circuits 4250, a memory 4260, a converter 4270, a data communication interface 4280, and one or more output devices 4290. Electrical components 4200 may be mounted on a single printed circuit board assembly (PCBA). In an alternative form, the RPT device 4000 may include more than one PCBA.

[0221] The central controller 4230 of the RPT device 4000 is programmed to execute a set of one or more algorithm modules 4300, preferably including a preprocessing module 4310, a treatment engine module 4320, a treatment control module 4330, and more preferably a fault status module 4340.

[0222] Mechanical and pneumatic components of the RPT device

[0223] The RPT device may include one or more of the following components in an integral unit. In an alternative form, one or more of the following components may be configured as separate units.

[0224] air filter

[0225] One form of RPT device according to the present technology may include one air filter 4110, or multiple air filters 4110.

[0226] In one configuration, the inlet air filter 4112 is positioned at the beginning of the pneumatic path upstream of the pressure generator 4140.

[0227] In one configuration, an outlet air filter 4113, such as an antibacterial filter, is positioned between the outlet of the pneumatic block 4056 and the patient interface 3000.

[0228] muffler

[0229] One form of RPT device according to the present technology may include one muffler 4120 or multiple mufflers 4118.

[0230] In one embodiment of this technology, the inlet silencer 4122 is positioned in the pneumatic path upstream of the pressure generator 4140.

[0231] In one embodiment of this technology, the outlet silencer 4121 is positioned in the pneumatic path between the pressure generator 4140 and the patient interface 3000.

[0232] pressure generator

[0233] In one form of this technology, the pressure generator 4140 for generating a positive pressure airflow or air supply is a controllable blower 4242. For example, the blower 4242 may include a brushless DC motor 4244 having one or more impellers housed in a volute. The blower may deliver the air supply, for example, at a rate up to about 120 liters per minute and at a positive pressure ranging from about 4 cmH2O to about 20 cmH2O, or in other forms up to about 30 cmH2O. The blower may be as described in any of the following patents or patent applications, which are incorporated herein by reference in their entirety: U.S. Patent No. 7,866,944; U.S. Patent No. 8,638,014; U.S. Patent No. 8,636,479; and PCT Patent Application No. WO 2013 / 020167.

[0234] The pressure generator 4140 is controlled by the treatment device controller 4240.

[0235] In other words, the pressure generator 4140 can be a piston-driven pump, a pressure regulator (e.g., a compressed air reservoir) connected to a high-pressure source, or a bellows.

[0236] converter

[0237] The transducer can be located inside or outside the RPT device. An external transducer can be positioned, for example, on or as part of an air circuit such as a patient interface. An external transducer can be in the form of a non-contact sensor, such as a Doppler radar motion sensor that transmits or transfers data to the RPT device.

[0238] In one embodiment of this technology, one or more converters 4270 may be located upstream and / or downstream of pressure generator 4140. One or more converters 4270 may be configured and arranged to measure characteristics such as flow rate, pressure, or temperature at that point in the pneumatic path.

[0239] In one form of this technology, one or more converters 4270 may be positioned proximal to the patient interface 3000.

[0240] In one embodiment, the signal from converter 4270 may be filtered, for example, by low-pass filtering, high-pass filtering, or band-pass filtering.

[0241] Flow sensor

[0242] The flow sensor 4130 according to this technology can be based on a differential pressure converter, such as the SDP600 series differential pressure converter from SENSIRION.

[0243] In one configuration, a signal representing flow rate is received from the flow sensor 4130 via a central controller 4230.

[0244] pressure sensor

[0245] The pressure sensor 4128 according to this technology is positioned in fluid communication with a pneumatic path. An example of a suitable pressure transducer is a sensor from the HONEYWELLAS DX series. An alternative suitable pressure transducer is a sensor from the GENERAL ELECTRIC NPA series.

[0246] In one configuration, a signal from a pressure sensor 4128 can be received via a central controller 4230.

[0247] Motor speed converter

[0248] In one embodiment of this technology, a motor speed converter 4276 is used to determine the rotational speed of the motor 4244 and / or the blower 4242. The motor speed signal from the motor speed converter 4276 can be provided to the treatment device controller 4240. The motor speed converter 4276 can be, for example, a speed sensor, such as a Hall effect sensor.

[0249] Anti-overflow valve

[0250] In one embodiment of this technology, an anti-backflow valve 4160 is positioned between the humidifier 5000 and the pneumatic block 4056. The anti-backflow valve is constructed and arranged to reduce the risk of water flowing upstream from the humidifier 5000 to, for example, the motor 4244.

[0251] air circuit

[0252] According to one aspect of the art, an air circuit 4170 includes at least one conduit or tube that is configured and arranged in use to allow airflow or gas to travel between two components, such as a pneumatic block 4056 and a patient interface 3000.

[0253] Specifically, the air circuit 4170 can be fluidly connected to the outlet of the pneumatic block 4056 and the patient interface 3000. The air circuit configuration may include, for example... Figure 1AThe single-branch configuration is shown. The single-branch body circuit can be used with a ventilator. The ventilator can be provided as a separate component, such as an anti-asphyxiation valve that fits into the air delivery tubing, or it can be included as part of the patient interface. The air delivery tubing connects to the outlet of a device, such as a ventilator or humidifier. In this single-branch ventilation configuration, inhaled air or gas flows from the RPT device through the air delivery tubing to the patient interface for delivery to the patient, and the patient's exhaled gas is expelled through the ventilator. The RPT device provides positive pressure at the ventilator to ensure that the patient's exhaled gas is expelled.

[0254] In an alternative configuration, a single-branch circuit can be used with a proximal pneumatic valve. The proximal pneumatic valve is located near the patient interface end of the air delivery tubing. The opposite end of the air delivery tubing connects to the device's outlet, such as a ventilator or humidifier. A small tube also connects between the device and the proximal pneumatic valve to provide a pressure control line. The RPT device applies control pressure to the proximal pneumatic valve to control the opening and closing of its exhaust port. During inspiration, the valve is fully closed, directing all airflow to the patient interface. During expiration, the valve is proportionally controlled to allow the patient to expel air from the exhaust port but at a specified back pressure (called positive end-expiratory pressure (PEEP)). The RPT device also continues to output a bias flow to ensure accurate control of PEEP and to counteract any leakage at the patient interface. The air pressure at the patient interface can be monitored using a pressure sensing line connected to the proximal pressure sensor within the RPT device.

[0255] In another configuration, a dual-branch circuit can be used. The dual-branch circuit comprises two tubes: an inspiratory tube that delivers air from the RPT device to the patient during inspiration; and an expiratory tube that delivers exhaled air from the patient to the expiratory port of the RPT device, and then out through the exhaust port. The two tubes can be geometrically arranged side-by-side or coaxially. The airflow between the expiratory and exhaust ports can be regulated by a pneumatic valve located inside the RPT device.

[0256] During inspiration, the valve closes completely, directing all airflow to the patient. During expiration, the valve is proportionally controlled to allow the patient to exhale from the outlet but to the specified PEEP pressure. The RPT device also continues to output bias flow to ensure accurate PEEP control and to counteract any leakage at the patient interface. The air pressure at the patient is monitored during inspiration via a proximal pressure sensor connected to the expiratory tubing within the RPT device; and during expiration via an output pressure sensor connected to the inspiratory tubing.

[0257] In some forms, the air circuit 4170 may include one or more heating elements configured to heat the air in the air circuit, for example, to maintain or raise the temperature of the air. For a dual-branch circuit, the inhalation tube or the exhalation tube, or both, may be heated. The heating element may be in the form of a heating wire circuit and may include one or more transducers, such as temperature sensors. In one form, the heating wire circuit may be helically wound around the axis of the air circuit 4170. The heating element may communicate with a controller such as a central controller 4230 or a humidifier controller 5250. An example of an air circuit 4170 including a heating wire circuit is described in U.S. Patent 8,733,349, which is incorporated herein by reference in its entirety.

[0258] Oxygen delivery

[0259] In one form of this technology, supplemental oxygen 4180 is delivered to one or more points in the pneumatic path (such as upstream of pneumatic block 4056), air circuit 4170 and / or patient interface 3000.

[0260] RPT device electrical components

[0261] power supply

[0262] The power supply 4210 can be located inside or outside the outer housing 4012 of the RPT device 4000.

[0263] In one embodiment of this technology, power supply 4210 supplies power only to RPT device 4000. In another embodiment of the invention, power supply 4210 supplies power to both RPT device 4000 and humidifier 5000. The power supply may include a power management system that controls the power supplied from internal and external batteries, as described in WO 2015 / 063218, which is incorporated herein by reference in its entirety.

[0264] Input device

[0265] In one form of this technology, the RPT device 4000 includes one or more input devices 4220 in the form of buttons, switches, or dials to allow personnel to interact with the device. The buttons, switches, or dials can be physical devices or software devices accessed via a touchscreen. In one form, the buttons, switches, or dials can be physically connected to an external housing 4012, or in another form, they can communicate wirelessly with a receiver electrically connected to a central controller 4230.

[0266] In one form, the input device 4220 may be configured or arranged to allow a person to select values ​​and / or menu options.

[0267] Central controller

[0268] In one form of this technology, the central controller 4230 is one or more processors adapted to control the RPT device 4000.

[0269] Suitable processors may include x86 Intel processors, based on those from ARM Holdings. Processors such as the STM32 series microcontrollers from ST Microelectronics. In some alternative forms of this technology, 32-bit RISC CPUs such as the STR9 series microcontrollers from ST Microelectronics, or 16-bit RISC CPUs such as the MSP430 series microcontrollers from Texas Instruments, are equally applicable.

[0270] In one form of this technology, the central controller 4230 is a dedicated electronic circuit.

[0271] In one form, the central controller 4230 is an application-specific integrated circuit (ASIC). In another form, the central controller 4230 includes discrete electronic components.

[0272] The central controller 4230 can be configured to receive input signals from one or more converters 4270, one or more input devices 4220, and humidifier 5000.

[0273] The central controller 4230 can be configured to provide output signals to one or more output devices 4290, treatment device controller 4240, data communication interface 4280 and humidifier 5000.

[0274] In some forms of this technology, the central controller 4230 is configured to implement one or more methods described herein, such as one or more algorithms 4300 represented as computer programs, which are stored in a non-transitory computer-readable storage medium such as memory 4260. In some forms of this technology, the central controller 4230 may be integrated with the RPT device 4000. However, in some forms of this technology, some methods may be performed by a remote positioning device. For example, the remote positioning device may determine the control settings of the ventilator or detect respiratory-related events by analyzing stored data such as from any of the sensors described herein.

[0275] clock

[0276] RPT device 4000 may include a clock 4232 connected to central controller 4230.

[0277] Treatment device controller

[0278] In one form of this technology, the treatment device controller 4240 is a treatment control module 4330, which constitutes part of the algorithm 4300 executed by the central controller 4230.

[0279] In one embodiment of this technology, the treatment device controller 4240 is a dedicated motor control integrated circuit. For example, in one embodiment, an MC33035 brushless DC motor controller manufactured by ONSEMI is used.

[0280] Protection circuit

[0281] One or more protection circuits 4250 according to the present technology may include electrical protection circuits, temperature and / or pressure safety circuits.

[0282] memory

[0283] According to one embodiment of the present technology, the RPT device 4000 includes a memory 4260, such as non-volatile memory. In some embodiments, the memory 4260 may include battery-powered static RAM. In some embodiments, the memory 4260 may include volatile RAM.

[0284] The memory 4260 can be located on the PCBA. The memory 4260 can be in the form of EEPROM or NAND flash memory.

[0285] Alternatively or alternatively, the RPT device 4000 includes a removable memory 4260, such as a memory card made according to the Secure Digital (SD) standard.

[0286] In one form of this technology, memory 4260 is used as a non-transitory computer-readable storage medium storing computer program instructions representing one or more methods described herein, such as one or more algorithms 4300.

[0287] Data communication system

[0288] In one embodiment of this technology, a data communication interface 4280 is provided and connected to a central controller 4230. The data communication interface 4280 can be connected to a remote external communication network 4282 and / or a local external communication network 4284. The remote external communication network 4282 can be connected to a remote external device 4286. The local external communication network 4284 can be connected to a local external device 4288.

[0289] In one embodiment, the data communication interface 4280 is part of the central controller 4230. In another embodiment, the data communication interface 4280 is separate from the central controller 4230 and may include an integrated circuit or a processor.

[0290] In one embodiment, the remote external communication network 4282 is the Internet. The data communication interface 4280 can connect to the Internet using wired communication (e.g., via Ethernet or fiber optic) or wireless protocols (e.g., CDMA, GSM, LTE).

[0291] In one form, the local external communication network 4284 utilizes one or more communication standards, such as Bluetooth or consumer infrared protocols.

[0292] In one form, the remote external device 4286 can be one or more computers, such as a cluster of networked computers. In another form, the remote external device 4286 can be a virtual computer rather than a physical computer. In either case, this remote external device 4286 can be accessed by appropriately authorized personnel, such as clinicians.

[0293] The local external device 4288 can be a personal computer, mobile phone, tablet, or remote control device.

[0294] Includes optional display and alarm output devices.

[0295] The output device 4290 according to this technology can take the form of one or more of visual, audio, and tactile units. The visual display can be a liquid crystal display (LCD) or a light-emitting diode (LED) display.

[0296] Display driver

[0297] The display driver 4292 receives characters, symbols, or images as input for display on the display 4294 and converts them into commands that cause the display 4294 to display those characters, symbols, or images.

[0298] monitor

[0299] The display 4294 is configured to visually display characters, symbols, or images in response to commands received from the display driver 4292.

[0300] RPT device algorithm

[0301] Preprocessing module

[0302] According to one form of the present technology, a preprocessing module 4310 receives a signal from a converter 4270 (e.g., a flow sensor 4130 or a pressure sensor 4128) as input and performs one or more processing steps to calculate one or more output values ​​that will be used as input to another module (e.g., a treatment engine module 4320).

[0303] In one form of this technology, the output values ​​include interface or mask pressure Pm, breathing flow rate Qr, and leakage flow rate Ql.

[0304] In various forms of this technology, the preprocessing module 4310 includes one or more of the following algorithms: pressure compensation 4312, ventilation flow estimation 4314, leakage flow estimation 4316, and respiratory flow estimation 4318.

[0305] Stress compensation

[0306] In one form of this technology, pressure compensation algorithm 4312 receives a signal indicating the pressure in the pneumatic path near the outlet of the pneumatic block as input. Pressure compensation algorithm 4312 estimates the pressure drop through air circuit 4170 and provides the estimated pressure Pm in patient interface 3000 as output.

[0307] Ventilation flow rate estimation

[0308] In one form of this technology, the ventilation flow estimation algorithm 4314 receives the estimated pressure Pm in the patient interface 3000 as input and estimates the air ventilation flow Qv from the air vent 3400 in the patient interface 3000.

[0309] Leakage flow estimation

[0310] In one form of this technology, the leakage flow estimation algorithm 4316 receives the total flow rate Qt and the exhaust flow rate Qv as inputs and provides an estimate of the leakage flow rate Ql as output. In another form, the leakage flow estimation algorithm estimates the leakage flow rate Ql by calculating the average of the difference between the total flow rate Qt and the ventilation flow rate Qv over a sufficiently long period of time that includes several respiratory cycles (e.g., about 10 seconds).

[0311] In one form, the leakage flow estimation algorithm 4316 receives the total flow rate Qt, the ventilation flow rate Qv, and the estimated pressure Pm from the patient interface 3000 as inputs, and provides the leakage flow rate Ql as output by calculating the leakage conductivity and determining the leakage flow rate Ql as a function of the leakage conductivity and pressure Pm. The leakage conductivity is calculated as the quotient of the low-pass filtered non-ventilation flow rate and the low-pass filtered square root of the pressure Pm, which is equal to the difference between the total flow rate Qt and the ventilation flow rate Qv, where the low-pass filter time constant has a sufficiently long time to include the value of several respiratory cycles (e.g., approximately 10 seconds). The leakage flow rate Ql can be estimated as the product of the leakage conductivity and the pressure Pm.

[0312] Respiratory flow estimation

[0313] In one form of this technology, the respiratory flow estimation algorithm 4318 receives total flow rate Qt, ventilatory flow rate Qv, and leakage flow rate Ql as inputs, and estimates the air respiratory flow rate Qr to the patient by subtracting the ventilatory flow rate Qv and leakage flow rate Ql from the total flow rate Qt.

[0314] Healing Engine Module

[0315] In one form of this technology, the treatment engine module 4320 receives one or more of the pressure Pm and the airflow rate Qr to the patient from the patient interface 3000 as inputs, and provides one or more treatment parameters as outputs.

[0316] In one form of this technique, the treatment parameter is the treatment pressure Pt.

[0317] In one form of this technique, the treatment parameters are one or more of amplitude, baseline pressure, and target ventilation.

[0318] In various forms, the treatment engine module 4320 includes one or more of the following algorithms: phase determination 4321, waveform determination 4322, ventilation determination 4323, inspiratory flow restriction determination 4324, apnea / insufficiency determination 4325, snoring determination 4326, airway patency determination 4327, target ventilation determination 4328, and treatment parameter determination 4329.

[0319] Phase determination

[0320] In one form of this technology, the RPT device has an uncertain phase of 4000.

[0321] In one form of this technology, the phase determination algorithm 4321 receives a signal indicating respiratory flow Qr as input and provides the phase φ of the patient's current respiratory cycle as output.

[0322] In some forms known as discrete phase determination, the phase output φ is a discrete variable. One implementation of discrete phase determination provides a dual-valued phase output with an inspiratory or expiratory value, respectively, at the detection of the start of spontaneous inspiration and expiration, for example, values ​​represented as 0 and 0.5 revolutions, respectively. The RPT device 4000, which performs "triggering" and "cycling," effectively performs discrete phase determination because the trigger and cycling points are the moments of phase change from expiration to inspiration and from inspiration to expiration, respectively. In one implementation of dual-valued phase determination, when the respiratory flow rate Qr has a value exceeding a positive threshold, the phase output is determined to be a discrete value of 0 (thus "triggering" the RPT device 4000), and when the respiratory flow rate Qr has a value more negative than a negative threshold, the phase output is determined to be a discrete value of 0.5 revolutions (thus "cycling" the RPT device 4000).

[0323] Another implementation of discrete phase determination provides a three-valued phase output Φ, which has one of the values ​​for inhalation, midpoint of inhalation pause, and exhalation.

[0324] In other forms known as continuous phase determination, the phase output Φ is a continuous value, such as varying from 0 to 1 revolution or 0 to 2 radians. The RPT device 4000 performing continuous phase determination can be triggered and cycled when the continuous phase reaches 0 and 0.5 revolutions, respectively. In one embodiment of continuous phase determination, fuzzy logic analysis of the respiratory flow Qr is used to determine the continuous value of the phase Φ. The continuous value of the phase determined in this embodiment is generally referred to as the "fuzzy phase". In one embodiment of the fuzzy phase determination algorithm 4321, the following rule is applied to the respiratory flow Qr:

[0325] 1. If the respiratory flow is zero and increases rapidly, the phase is 0 revolutions.

[0326] 2. If the respiratory flow is large, positive, and stable, the phase is 0.25 revolutions.

[0327] 3. If the respiratory flow is zero and decreases rapidly, the phase is 0.5 revolutions.

[0328] 4. If the respiratory flow is significantly negative and stable, the phase is 0.75 revolutions.

[0329] 5. If the respiratory flow is zero and stable and the absolute value of the 5-second low-pass filter for the respiratory flow is large, then the phase is 0.9 revolutions.

[0330] 6. If the respiratory flow is positive and it is the expiratory phase, the phase is 0 revolutions.

[0331] 7. If the respiratory flow is negative and it is the inspiratory phase, the phase is 0.5 revolutions.

[0332] 8. If the absolute value of the 5-second low-pass filter for respiratory flow is large, and the phase increases at a steady rate equal to the patient's respiratory rate, then the low-pass filter has a time constant of 20 seconds.

[0333] The output of each rule can be represented as a vector, with its phase being the result of the rule and its amplitude being the degree of ambiguity of the rule being true. The degree of ambiguity for respiratory flow such as "large" or "stable" is determined using an appropriate membership function. The results of the rules, represented as vectors, are then combined using certain functions, such as taking the centroid. In such combinations, the rules can be weighted equally or differently.

[0334] In another embodiment of continuous phase determination, the inspiratory time Ti and expiratory time Te are first estimated based on the respiratory flow rate Qr. The phase φ is then determined as half the proportion of the inspiratory time Ti that has elapsed since the previous trigger moment, or 0.5 revolutions plus half the proportion of the expiratory time Te that has elapsed since the previous cycle moment (whichever is more recent).

[0335] In some forms of this technology, the continuous determination of circuit impedance or circuit conductivity values ​​can be performed based on measured or estimated pressure (P) and flow (Q) parameters. The determined continuous impedance or conductivity values ​​can be used to distinguish passively disconnected circuits from circuits connected to a breathing patient, enabling the determination of circuit connection status. Passively disconnected circuits provide a relatively constant or unchanging conductivity or impedance value over time. Conversely, breathing circuits connected to a breathing patient provide a variable conductivity or impedance value over time.

[0336] In other forms of this technology, the continuous determination of instantaneous impedance or conductivity values ​​based on measured or estimated pressure (P) and flow (q) parameters can be used to estimate the phase of a patient's breathing. Instantaneous impedance or conductivity values ​​can be filtered to remove noise from the signal. For example, while a disconnected loop will have relatively constant conductivity or impedance measurements, conversely, a breathing patient connected to the loop can have a characteristic shape or distribution of conductivity or impedance values ​​within each corresponding breathing phase. Because this distribution contains information about pressure and flow relative to baseline conductivity levels, it may be more sensitive to patient activity than these parameters alone. For example, depending on the loop type, inspiratory activity may be associated with an increase in delivery flow or a decrease in airway pressure, or both. The opposite may occur during a patient's expiratory effort. The conductivity or impedance distribution used to estimate breathing phases can therefore be more sensitive and versatile in loop configurations. Thus, conductivity or impedance distributions or absolute amplitudes can be used to trigger and cycle the RPT device in sync with patient effort, or to provide clinicians with feedback on potential asynchrony between the machine's breathing phase and the patient's breathing phase. For example, the detection of “invalidity” triggering efforts can be performed in a manner similar to that described in U.S. Patent No. 8,603,006 and U.S. Patent Application No. 13 / 264,4012, published in U.S. 2012 / 0037159, the contents of which are incorporated herein by reference in their entirety.

[0337] Figure 7F(i) shows exemplary recording lines of respiratory flow and airway pressure for a patient simulating breathing on the system during CPAP therapy. Airway pressure 7108 remains relatively constant, and respiratory flow 7106 cycles through inspiratory and expiratory phases. Figure 7F(ii) shows the instantaneous conductance (G) 7112 determined based on the respiratory flow and airway pressure values. As indicated, the instantaneous conductance shows a respiratory cycle similar to the inspiratory and expiratory phases in the flow recording line 7106. The change in instantaneous conductance over time (dG / dt) 7114 shows a conductance that varies continuously over time, indicating the patient's breathing on the system.

[0338] Figure 7G(i) shows exemplary recording lines for respiratory flow 7106 and a defined instantaneous conductance 7112. An inspiratory phase 7102, an expiratory phase 7104, and a flow trigger point 7120 are indicated. The flow trigger point 7120 can be used to trigger a new inspiratory phase. A pressure trigger point 7130 is also indicated and can be used to trigger a new inspiratory phase. In Figure 7G(ii), the same defined instantaneous conductance 7112 recording line is provided, and a conductance trigger threshold 7100 is indicated. Whenever the instantaneous conductance 7112 is increasing and crosses the conductance trigger threshold 7100, the system can trigger a new inspiratory phase. Some instances where a conductance trigger event will trigger a new inspiratory phase are indicated at 7110.

[0339] Waveform determination

[0340] In one form of this technology, the treatment parameter determination algorithm 4329 provides an approximately constant treatment pressure throughout the patient's respiratory cycle.

[0341] In other forms of this technology, the treatment control module 4330 controls the pressure generator 4140 to provide a treatment pressure Pt that varies according to the phase φ of the patient's respiratory cycle, based on the waveform template Π(Φ).

[0342] In one form of this technology, waveform determination algorithm 4322 provides a waveform template Π(Φ) with values ​​in the range [0, 1] on the domain of phase values ​​provided by phase determination algorithm 4321 for use by treatment parameter determination algorithm 4329.

[0343] In a form suitable for discrete or continuous phase values, the waveform template Π(Φ) is a square wave template with a value of 1 for phase values ​​up to and including 0.5 revolutions, and a value of 0 for phase values ​​greater than 0.5 revolutions. In a form suitable for continuous phase values, the waveform template Π(Φ) includes two smoothly curved sections: a smooth curve (e.g., raised cosine) rising from 0 to 1 for phase values ​​up to 0.5 revolutions, and a smooth curve (e.g., exponential) decaying from 1 to 0 for phase values ​​greater than 0.5 revolutions. In a form suitable for continuous phase values, the waveform template Π(Φ) is based on a square wave, but has a smooth rise from 0 to 1 for phase values ​​with a rise time significantly less than 0.5 revolutions, and a smooth fall from 1 to 0 for phase values ​​within a fall time after 0.5 revolutions.

[0344] In some forms of this technology, the waveform determination algorithm 4322 selects a waveform template Π(Φ) from a waveform template library based on the settings of the PΠT device 4000. Each waveform template Π(Φ) in the library can provide a lookup table for values ​​relative to phase values. In other forms, the waveform determination algorithm 4322 uses a predetermined function form, possibly parameterized by one or more parameters (e.g., the time constant of the exponential curve portion), to calculate the "on-fly" waveform template Π(Φ). The parameters of the function form can be predetermined or depend on the current state of the patient 1000.

[0345] In some forms of discrete dual-phase measurements applicable to inhalation (Φ = 0 rpm) or exhalation (Φ = 0.5 rpm) in this technique, waveform determination algorithm 4322 calculates the "real-time" waveform template as a function of both the discrete phase measured since the most recent triggering moment and time t. In one such form, waveform determination algorithm 4322 calculates the waveform template Π(Φ, t) in both parts (inhalation and exhalation) as follows:

[0346]

[0347] Where i(t) and e(t) are the inspiratory and expiratory portions of the waveform template Π(Φ,t). In one such form, the inspiratory portion i(t) of the waveform template is a smooth rise from 0 to 1 parameterized by the rise time, and the expiratory portion Πe(t) of the waveform template is a smooth fall from 1 to 0 parameterized by the fall time.

[0348] Ventilation volume determination

[0349] In one form of this technology, the ventilation determination algorithm 4323 receives respiratory flow Qr as input and determines a measurement indicating the current patient ventilation Vent.

[0350] In some implementations, the ventilation determination algorithm 4323 determines a measured value of the ventilation volume Vent, which is an estimate of the actual patient ventilation volume. One such implementation involves optionally filtering half the absolute value of the respiratory flow Qr with a low-pass filter (such as a second-order Bessel low-pass filter with an angular frequency of 0.11 Hz).

[0351] In other embodiments, ventilation determination algorithm 4323 determines a measured value of ventilation volume Vent, which is approximately proportional to the actual patient ventilation volume. One such embodiment estimates the peak respiratory flow Q during the inspiratory portion of the cycle. 峰值This, along with many other procedures involving sampling respiratory flow Qr, produces measurements that are approximately proportional to the tidal volume, provided that the shape of the flow waveform does not change significantly (here, the shapes of two breaths are considered similar when the flow waveforms of breaths with normal time and amplitude are similar). Some simple examples include respiratory flow with a positive median, the median of the absolute values ​​of respiratory flow, and the standard deviation of the flow. Any linear combination of any order statistics of the absolute values ​​of respiratory flow using positive coefficients, or even some using both positive and negative coefficients, is approximately proportional to the tidal volume. Another example is the average of the respiratory flow at the midpoint K proportion (over time) of the inspiratory portion, where 0 < K < 1. If the flow shape remains constant, any number of measurements can exist that are precisely proportional to the tidal volume.

[0352] Inspiratory flow limit determined

[0353] In one form of this technology, the central controller 4230 executes an inspiratory flow limit determination algorithm 4324 for determining the degree of inspiratory flow limit.

[0354] In one form, the inspiratory flow limitation determination algorithm 4324 receives the respiratory flow signal Qr as input and provides a measure of the degree of inspiratory flow limitation exhibited by the inspiratory portion of the breath as output.

[0355] Determining respiratory arrest and insufficiency

[0356] In one form of this technology, the central controller 4230 executes a breathing apnea / insufficiency determination algorithm 4325 to determine the presence of breathing apnea and / or insufficiency.

[0357] The apnea / insufficiency determination algorithm 4325 receives the respiratory flow signal Qr as input and provides a flag indicating that apnea or insufficiency has been detected as output.

[0358] In one form, apnea is considered detected when a function of respiratory flow Qr falls below a flow threshold within a predetermined time period. This function can determine peak flow, relatively short-term average flow, or an intermediate flow between relatively short-term average and peak flow (e.g., RMS flow). The flow threshold can be a measurement of flow over a relatively long period.

[0359] In one form, insufficiency is considered detected when a function of respiratory flow Qr falls below a second flow threshold within a predetermined time period. This function can be determined by peak flow, a relatively short-term average flow, or an intermediate flow between a relatively short-term average flow and peak flow (e.g., RMS flow). The second flow threshold can be a measurement of a relatively long-term flow. The second flow threshold is greater than the flow threshold used to detect respiratory arrest.

[0360] Snoring confirmed

[0361] In one form of this technology, the central controller 4230 executes one or more snoring determination algorithms 4326 for determining the degree of snoring.

[0362] In one form, the snoring determination algorithm 4326 receives a signal of respiratory flow Qr as input and provides a measure of the degree of snoring presence as output.

[0363] The snoring determination algorithm 4326 may include the step of determining the flow signal strength in the range of 30-300 Hz. Furthermore, the snoring determination algorithm 4326 may include the step of filtering the signal of the respiratory flow Qr to reduce background noise (e.g., the sound of airflow from the blower in the system).

[0364] Airway patency confirmed

[0365] In one form of this technology, the central controller 4230 executes one or more airway occupancy determination algorithms 4327 for determining airway occupancy.

[0366] In one form, the airway occupancy determination algorithm 4327 receives the respiratory flow signal Qr as input and determines the power of the signal in a frequency range of approximately 0.75 Hz to approximately 3 Hz. A peak in this frequency range is considered an indication of airway occupancy. The absence of a peak is considered an indication of airway closure.

[0367] In one approach, the frequency range in which the peak value is located is the frequency of small forced oscillations in the treatment pressure Pt. In one embodiment, the forced oscillation frequency is 2 Hz and the amplitude is approximately 1 cmH2O.

[0368] In one form, the airway occupancy determination algorithm 4327 receives the respiratory flow signal Qr as input and determines the presence or absence of a cardiac signal. The absence of a cardiac signal is considered an indication of airway closure.

[0369] 4.4.3.2.8 Determination of Target Ventilation Rate

[0370] In one form of this technology, the central controller 4230 takes the measured value of the current ventilation volume Vent as input and executes one or more target ventilation volume determination algorithms 4328 to determine the target value Vtgt for measuring the ventilation volume.

[0371] In some forms of this technology, there is no target ventilation determination algorithm 4328, and the target value Vtgt is predetermined, for example by hard coding during the configuration of the RPT device 4000 or by manual input via the input device 4220.

[0372] In other forms of this technology, such as adaptive servo ventilation (ASV), the target ventilation determination algorithm 4328 calculates the target value Vtgt from the value Vtyp, which indicates the patient's typical recent ventilation.

[0373] In some forms of adaptive servo ventilation, the target ventilation volume Vtgt is calculated as a high percentage, but less than, of the typical recent ventilation volume Vtyp. This high percentage in such forms may be in the range of (80%, 100%), (85%, 95%), or (87%, 92%).

[0374] In other forms of adaptive servo ventilation, the target ventilation volume Vtgt is calculated to be several times larger than the typical recent ventilation volume Vtyp.

[0375] A typical recent ventilation volume (Vtyp) is a value in which current ventilation volume (Vent) measurements at multiple moments within a predetermined time range tend to cluster around their distribution; that is, it is a measure of the central tendency of the current ventilation volume measurements in recent history. In one implementation of the target ventilation volume determination algorithm 4328, the recent history is on the order of minutes, but should in any case be longer than the time range of the tidal crescendo and fading cycles. The target ventilation volume determination algorithm 4328 can use a variety of known measures of central tendency to determine the typical recent ventilation volume (Vtyp) from the current ventilation volume (Vent) measurement. One such measurement is the output of a low-pass filter on the current ventilation volume (Vent) measurement, with a time constant equal to 100 seconds.

[0376] Treatment parameters determined

[0377] In some forms of this technology, the central controller 4230 executes one or more treatment parameter determination algorithms 4329 to determine one or more treatment parameters using values ​​returned by one or more other algorithms in the treatment engine module 4320.

[0378] In one form of this technology, the treatment parameter is the instantaneous treatment pressure Pt. In one embodiment of this form, the treatment parameter determination algorithm 4329 uses the following equation to determine the treatment pressure Pt:

[0379] Pt=AΠ(Φ,t)+P0 (1)

[0380] in:

[0381] A is the amplitude.

[0382] ·(Φ, t) is the waveform template value (ranging from 0 to 1) at the current phase value and time t.

[0383] P0 is the base pressure.

[0384] If the waveform determination algorithm 4322 provides a waveform template Π(Φ, t) as a numerical lookup table indexed by phase, the treatment parameter determination algorithm 4329 applies equation (1) by locating the nearest lookup table entry to the current phase value returned by the phase determination algorithm 4321, or by interpolation between two entries across the current phase value.

[0385] Depending on the selected respiratory pressure treatment mode, the values ​​of amplitude A and baseline pressure P0 can be set by treatment parameter determination algorithm 4329.

[0386] Treatment control module

[0387] According to one aspect of the present technology, the treatment control module 4330 receives treatment parameters as input from the treatment parameter determination algorithm 4329 of the treatment engine module 4320, and controls the pressure generator 4140 to deliver an airflow according to the treatment parameters.

[0388] In one form of this technology, the treatment parameter is the treatment pressure Pt, and the treatment control module 4330 controls the pressure generator 4140 to deliver an airflow, wherein the mask pressure Pm of the airflow at the patient interface 3000 is equal to the treatment pressure Pt.

[0389] Fault Detection

[0390] In one form of this technology, the central controller 4230 executes one or more methods 4340 for detecting fault conditions. The fault conditions detected by the one or more methods 4340 may include at least one of the following:

[0391] • Power failure (no power, or insufficient power).

[0392] • Converter fault detection

[0393] • The presence of the component cannot be detected

[0394] • Operating parameters are outside the recommended range (e.g., pressure, flow rate, temperature, PaO2).

[0395] • The test alarm failed to generate a detectable alarm signal.

[0396] • The patient's circuit is disconnected.

[0397] Upon detecting a fault, the corresponding algorithm signals the presence of a fault through one or more of the following methods:

[0398] • Activate auditory, visual, and / or dynamic (e.g., vibration) alarms

[0399] Sending messages to external devices

[0400] • Record events

[0401] The patient slightly disconnected

[0402] According to one form of this technology, for example as part of fault detection method 4340, the RPT device 4000 includes a circuit disconnection detection system that detects the occurrence of a patient circuit disconnection event and can activate messages or alarms to notify the patient, clinician, or caregiver that a patient circuit disconnection event has occurred or to change control parameters of the RPT device (such as stopping treatment, reducing pressure, reducing flow rate, or reducing motor speed) or combinations thereof. The patient circuit includes an air circuit 4170 and a patient interface 3000. The patient interface can include invasive, non-invasive, ventilated, or non-ventilated patient interfaces, including masks, tracheostomy tubes (cuffed or non-cuffed), suction / tube interfaces, oral devices, or any other such patient interfaces.

[0403] A loop disconnection detection system includes monitoring one or more disconnection parameters independent of the provided treatment mode (i.e., volume- or pressure-controlled treatment mode) and treatment settings. Disconnection parameters may include loop conductivity or loop impedance. In some forms, the instantaneous disconnection parameter (D...) can be used. i ) and disconnection threshold (D thres A comparison is made to detect the occurrence of a disconnection event.

[0404] In other forms, the transient disconnect parameter (Di) can be monitored against a relatively constant or unchanging distribution map indicating a passively disconnected circuit (i.e., the patient is not connected to the circuit). In this type of form, the level of variability of the transient disconnect parameter, which is continuously determined over time, can provide an indication of a patient circuit disconnection. For example, if the continuously determined transient disconnect parameter has substantially equal values ​​(i.e., no change or very small change over time), this would indicate a patient circuit disconnection. Conversely, continuously determined transient disconnect parameters with different values ​​(i.e., the level of variability over time) would indicate that the patient is connected to the patient circuit.

[0405] Figure 7H(i) shows the recording lines of respiratory flow 7106 and airway pressure 7108 when the ventilator is connected to the system simulating a patient breathing on the system. Figure 7H(ii) shows a graph of the values ​​of transient conductivity 7112 and transient impedance 7116 determined based on the respiratory flow 7106 and airway pressure 7108 in Figure 7H(i). Arrow 7122 indicates two respiratory cycles when the patient circuit is connected to the system. When simulating breathing on the patient circuit, both transient conductivity 7112 and transient impedance 7116 show values ​​that change over time. A circuit break occurs at 7118, and the transient conductivity 7112 and transient impedance 7116 show very small changes over time, indicating that a patient circuit break event has occurred.

[0406] Figure 7IA graph showing the instantaneous conductance over time for a pediatric patient connected to the RPT device via a dual-value endotracheal tube. A conductance threshold of 7050 is indicated. The arrow labeled NB indicates the normal breathing period of the connected patient circuit. Arrow DC indicates the period of extubation. When an extubation event occurs first, there is a delay of 7064 for a predetermined time limit 7064 until a response to the disconnection event is generated during 7054 to ensure a true disconnection event occurs. Arrow DT indicates the period when endotracheal tube disconnection occurs. When endotracheal tube disconnection occurs first, there is also a delay of 7064 for a predetermined time limit 7064 before a response to the disconnection event is generated during 7054. The disconnection event response 7054 can be in the form of activating an alarm or a message. In some forms, an indication can be displayed on the RPT device's user interface when a disconnection event (DC or DT) is first detected; however, in other forms, an alarm can be activated only after the predetermined time limit 7064 has expired.

[0407] Disconnection threshold (D) thrss The threshold loop conductivity or threshold loop impedance is the threshold loop conductivity value. For the same loop and fluid, conductivity and impedance can be considered as reciprocals of each other. Impedance (resistance) refers to the degree to which a loop portion impedes flow when a pressure difference is applied across the loop. Conductivity refers to the degree to which a loop portion conducts flow when a pressure difference is applied across the loop.

[0408] Figure 7AThis is a flowchart of a patient circuit disconnection detection method 7000 that can be performed by a controller of an RPT device 4000 of one form of the present technology. The method 7000 begins at 7010 and determines the type of patient circuit coupled to the RPT device at 7012. Determining the patient circuit type 7012 may include determining the configuration of an air circuit 4170 coupled to the RPT device 4000 and / or the type of a patient interface 3000 coupled to the air circuit 4170. Determining the patient circuit type 7012 may include determining the configuration of the air circuit, which includes one or more of invasive, non-invasive, ventilated or non-ventilated, single-branch circuit or dual-branch circuit. In one embodiment, the type of patient circuit may be input into the RPT device 4000 via an input device 4220. In another embodiment, the type of patient circuit, including the configuration of the air circuit 4170 or the type of the patient interface 3000, or both, may be determined by the RPT device 4000. One such implementation includes applying certain predetermined values ​​of pressure and / or flow rate during the setup phase of operation in the absence of a patient, and measuring the interface pressure and / or flow rate at each value. The resulting measurements can be used to infer the type of patient circuit. Another such implementation, disclosed in PCT Publication No. WO 2010 / 091462 (the entire contents of which are incorporated herein by reference), includes acoustic analysis of sound reflected from the patient circuit to determine its characteristics, including the configuration of the air circuit 4170 and / or the type of the patient interface 3000. In other such implementations, sensors of the RPT device 4000 can detect an identifier of the patient circuit type from tags on the air circuit and / or the patient interface, such as via radio frequency identification (e.g., RFID).

[0409] In step 7014, a disconnection threshold (D) is determined based on the type of patient circuit from step 7012. thres The value of ) is set based on the predicted impedance or predicted conductivity of the patient circuit and the expected leakage to the atmosphere provided by the patient circuit. thres This is used to determine a range of impedance or conductivity values ​​that can detect a "true" patient circuit disconnection while distinguishing it from the expected background leakage level in the patient circuit during use. The disconnection threshold can be empirically determined based on prior characterization of a range of different patient circuit types to determine an appropriate range of impedance or conductivity values. In some forms, the RPT device 4000 can use a lookup table to set an initial value for the disconnection threshold based on the type of patient circuit coupled to the RPT device.

[0410] Optionally, in some forms, patient information 7013 may also be provided to the RPT device and used as the basis for determining or setting a disconnection threshold. Patient information may include at least one of the following: patient type (e.g., adult or child), patient weight, patient height, and patient age.

[0411] To monitor patient circuit disconnection during treatment, the RPT device can be configured to repeatedly detect measurements or estimates of the instantaneous pressure (Pm) in the patient interface and the instantaneous flow rate (Qt) in the patient circuit in step 7016. As previously described, the RPT device may include one or more of pressure sensor 4128 or flow sensor 4130 to measure or estimate pressure or flow rate, respectively. In step 7018, an instantaneous disconnection parameter (D) can be calculated based on the instantaneous pressure (Pm) and flow rate (Q) inputs. i Instantaneous disconnection parameter (D) i It can be calculated as a loop impedance value or a loop conductivity value.

[0412] In step 7020, the instantaneous disconnection parameter (D) is... i ) and disconnection threshold (D thres A comparison is made to detect whether a loop disconnection event has occurred. If the comparison indicates a loop disconnection event, a Boolean disconnection indicator (Disc) can be set to True. A True disconnection indicator signals the occurrence of a loop disconnection event. In step 7022, the system detects whether a disconnection event has been detected, and if the result is no, in step 7024, a non-disconnection state is signaled by setting the disconnection indicator (Disc) to False, and method 7000 loops back to repeat the detection of instantaneous pressure and flow values ​​in 7016. If the result in step 7022 is "yes," a disconnection event is signaled in 7026 by setting the disconnection indicator (Disc) to True. Method 7000 can continue to monitor the disconnection state by looping back to the detection of instantaneous pressure and flow values ​​in 7016. In some forms, a True disconnection indicator can be provided when a disconnection event is detected, but when no disconnection event is detected, method 7000 loops back to repeat the detection of instantaneous pressure and flow values ​​at step 7016.

[0413] After setting the disconnect indication in 7026, a disconnect alarm, message, counter, or timer can be activated. In some forms, the RPT device can provide a first indication when a disconnect event is first detected. For example, output device 4290 may include display 4294, on which an indication of a detected loop disconnect event can be provided. The indication on display 4294 can be in the form of a message or light (e.g., turning on a light, changing color, or flashing an LED) or other forms of visual indication. The RPT device can also, or alternatively, activate a counter or timer to monitor continuous detection of disconnect events over a predetermined time period. Alarm or message activation may be provided only after continuous detection of disconnect events over the predetermined time period. Alternatively, a second indication other than the first indication, such as in the form of an audio indication, such as an alarm, can be provided when disconnect events are continuously detected over the predetermined time period. In some forms, the status of a disconnect parameter compared to a threshold can be continuously indicated on output device 4290 of RPT device 4000. Such a disconnect status indication can provide real-time feedback to users, caregivers, or clinicians regarding the status of disconnect detection and help adjust the disconnect threshold (D). thres The level of the disconnection threshold (D) is used to ensure that disconnection events are detected correctly. The disconnection status can indicate the currently set disconnection threshold (D). thres Whether a disconnection indication will be provided, and whether users, caregivers, or clinicians can use this status information to adjust or tune the disconnection threshold (D) thres For example, users, caregivers, or clinicians could intentionally disconnect patient circuits or expose patient interfaces to test currently set disconnect thresholds (D). thres Whether to detect a loop break event and provide a break indication (Disc) in either of these cases. The break threshold (D) can be adjusted. thres This prevents the provision of a disconnect indication when a patient interface leak occurs, while still detecting patient loop disconnect events. The disconnect status allows for monitoring of the performance of the patient loop disconnect detection system.

[0414] Figure 7B This is a flowchart of a loop disconnection detection method 7000A that can be executed by the controller of an RPT device 4000 of another form of this technology. In this form, the disconnection indication (Disc) must provide a predetermined time limit before activating the disconnection alarm. The steps 7000A from start 7010 to "disconnection event detected" 7022 are similar to those in method 7000A. Figure 7AMethod 7000, as shown, uses similar item numbers to indicate the same or substantially similar steps. Similarly, in method 7000A, if no disconnection event is detected in step 7022, the disconnection indication (Disc) is set to false in step 7024, or if it was previously set to false, it remains false. However, in addition, the timer is reset to zero in step 7038 before returning to step 7016 to monitor instantaneous pressure and flow.

[0415] Similarly, if the result in step 7022 is "yes," meaning a disconnection event is detected, then in step 7026 the disconnection indicator (Disc) is set to true, or if it was previously set to true, it remains true. Furthermore, in step 7032, if the timer was not previously started, the timer is started, or if the timer was previously started, the timer is incremented. The timer can count up or down to a predetermined time limit. The disconnection indicator (Disc) can also be displayed on the output device 4290 of the RPT device 4000 (e.g., a user interface) to indicate the disconnection status to the user, caregiver, or clinician. This display of the disconnection indicator can help tune the disconnection threshold (D). thres Or monitor the performance of the patient circuit disconnection detection system as described above, or both.

[0416] In step 7034, the current value of the timer is compared with a predetermined time limit. The predetermined time limit may include a set duration, such as 5 to 60 seconds, or 5 to 30 seconds, or some other time limit. Alternatively, the predetermined time limit may be in the form of a counter and include a predetermined number of breaths, such as a count of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more breaths. The set time limit can be adjusted via the input device 4220 in seconds or minutes for the set time length or for the set number of breaths.

[0417] If the current value of the timer is not greater than or equal to the predetermined time limit, method 7000A loops back to continue monitoring instantaneous pressure and flow input and detecting disconnection status over time.

[0418] If the current value of the timer is greater than or equal to a predetermined time limit, an alarm or message can be activated in step 7040 to signal one or more of the patient, clinician, or caregiver that a patient circuit disconnection event has occurred. Optionally, method 7000A loops back to continue monitoring instantaneous pressure and flow inputs and detecting the disconnection status.

[0419] Therefore, in this manner, when a "true" disconnection event is detected for the first time, the timer starts and continues to monitor for the continuous occurrence of disconnection events until a predetermined time limit is reached or exceeded. Once the predetermined time limit is reached after a series of disconnection events, the RPT device will activate an alarm or message. However, if a "false" disconnection indication is detected before the predetermined time limit is reached, the counter is reset and the predetermined time limit is not reached, so no alarm or message is activated. The disconnection system continues to determine instantaneous disconnection parameters and monitor the disconnection status.

[0420] The instantaneous disconnection parameter can be calculated as either or both of impedance and conductivity based on the measured or estimated pressure (Pm) at the patient interface and the measured or estimated volumetric flow rate (Qt) from the RPT device 4000. As previously mentioned, the RPT device may include one or more of pressure sensor 4128 or flow sensor 4130 to measure or estimate pressure or flow rate, respectively. The instantaneous disconnection parameter value can be filtered to remove noise from the signal.

[0421] In one form of this technology, the instantaneous disconnection parameter can be calculated based on a measured or estimated value (Pm) of the pressure at the patient interface and a measured flow rate (Qt). The disconnection parameter can be calculated based on the following equation related to the pressure loss at the patient interface:

[0422]

[0423] Where Pm is the pressure at the patient interface, Z is the impedance, ρ is the air density, and Qt is the measured flow rate. In some forms, the air density can be estimated based on ambient pressure and gas temperature. Ambient pressure and gas temperature can be measured via sensors or input into the device via input devices.

[0424] The equation [1] can be rearranged to provide an impedance (Z) determination, which can be used as a form of instantaneous disconnection parameter:

[0425]

[0426] In this form, the disconnect threshold will be the impedance threshold, and if the instantaneous impedance is less than the disconnect threshold impedance, the patient circuit is determined to be disconnected.

[0427] Equation [2] can be transformed to provide a conductivity (G) determination, which can be used as another form of the instantaneous disconnection parameter:

[0428]

[0429] In this form, the disconnection threshold will be the conductivity threshold, and if the instantaneous conductivity is greater than the disconnection threshold and the conductivity reaches a predetermined time limit, the patient circuit is determined to be disconnected.

[0430] In some forms of this technology, the transient disconnection parameter is determined at predetermined time intervals. The predetermined time interval may include one or more breaths or a duration in milliseconds or seconds. In one form, the transient disconnection parameter is determined at least once during each breath. For example, the transient disconnection parameter is determined during the inspiratory phase of a breath. In other forms, the transient disconnection parameter is determined multiple times per breath, including during the inspiratory and expiratory phases. The transient disconnection parameter is determined based on an input of pressure (P) and flow rate (Qt) provided at least once per breath, preferably at least once during the inspiratory phase, or at least once during the inspiratory phase and at least once during the expiratory phase.

[0431] In other forms, the instantaneous disconnection parameter can be detected at predetermined time intervals.

[0432] Instantaneous pressure and flow inputs can be measured or estimated based on sensor signals sampled during the respiratory cycle. The inspiratory sampling time can be configured to minimize the impact of large patient inspiratory efforts on the signal, for example, at the end of the inspiratory portion of the breath. For example, inspiratory pressure and flow inputs can be determined at a predetermined time before the cycle (e.g., 10-30 ms before the cycle) or at a predetermined time after a new breath is triggered (e.g., 100-300 ms after the trigger). Expiratory pressure and flow inputs can be determined at times when unstable flow (such as unstable flow associated with valve switching) can be avoided. For example, expiratory pressure and flow inputs can be determined at a predetermined time after the cycle (e.g., 100-300 ms or 200-250 ms) or at a predetermined time before the trigger (e.g., 10-50 ms before the trigger). The sampling time can be selected based on whether patient effort needs to be measured. If patient effort measurement is required, sampling can be performed at a time immediately following the detection of the trigger and cycle events. Alternatively, to perform measurements with minimal patient impact, sampling can be performed at a time immediately before the trigger and cycle.

[0433] Those skilled in the art will understand that other pressure loss equations can be used to determine the instantaneous disconnection parameters (conductivity or impedance).

[0434] In some configurations, the circuit disconnection detection system is always able to detect a patient circuit disconnection. In other configurations, the circuit disconnection detection system can be disabled for non-dependent patients (i.e., spontaneously breathing patients) or depending on the circuit configuration coupled to the RPT device. Preferably, the circuit disconnection detection system is not disabled for ventilation-dependent patients.

[0435] In some forms, the RPT device may allow the disconnect alarm to be silenced for a predetermined period of time, such as 30 seconds to 5 minutes, or 30 seconds, 60 seconds, 120 seconds, or some other duration, after which it may be reactivated. The disconnect alarm can be silenced via the input device 4220 of the RPT device 4000, for example, by pressing a button or dial on the input device 4220. In some forms, the duration of the alarm silence can be adjusted via the input device 4220. Adjustment can be performed by a clinician, patient, or caregiver.

[0436] In some forms of this technology, the disconnection threshold (D) can be adjusted based on a sensitivity setpoint. thres The sensitivity setting can be used to adjust the disconnect threshold (D). thres The sensitivity setting is tuned to the level of disconnection event detection. The sensitivity setting can be considered a disconnection tolerance factor. Before connecting to the patient, the sensitivity setting can be manually tuned by the user, caregiver, or clinician to test the disconnection system with the coupled patient circuit (including air circuit 4170 and patient interface 3000). The sensitivity setting is configured to increase the likelihood of successfully detecting a circuit disconnection and / or decrease the likelihood of falsely detecting a circuit disconnection and activating an alarm or message during treatment. The disconnection indicator (Disc) display on the output device 4290 of the RPT device 4000 can be used to assist in tuning the sensitivity setting.

[0437] In one form, the sensitivity setpoint can be manually set during the testing phase based on empirical testing, using a series of sensitivity setpoints, to determine the minimum sensitivity setpoint at which the disconnect threshold is just sensitive enough to correctly detect the circuit disconnection event as indicated by the disconnection indication step 7026. The sensitivity setpoint can be set at the determined sensitivity setpoint or at one or more increased sensitivity levels to prevent partial blockage of the air circuit, which could compromise the effectiveness of the disconnection system during disconnection. The testing phase can occur before or simultaneously with the provision of treatment, such as in the initial stage of treatment.

[0438] In some forms, during the testing phase for sensitivity setting, the RPT device can disable or reduce the predetermined time limit required to activate the disconnect alarm, allowing for immediate feedback to help adjust the sensitivity setting.

[0439] In some forms, the RPT device can be configured to provide feedback via an output device 4290 (such as on a display 4294) on a sensitivity setpoint level that would detect a loop disconnection event based on currently measured instantaneous disconnection parameters. The sensitivity setpoint feedback can be provided as real-time feedback or stored in memory for subsequent analysis.

[0440] The sensitivity setting can be a percentage between 1% and 100%, such as 5% to 100%, or a fraction or value such as 0.01 to 1, or any proportion. In some forms, the sensitivity setting can be selected from a predetermined range of settings between an upper and lower limit, such as 5% increments between 5% and 95%. The disconnect threshold can be adjusted by the sensitivity setting to provide a final disconnect threshold that can be used for comparison with transient disconnect parameters. In some forms, the higher the sensitivity setting, the more tolerant the final disconnect threshold is of leakage from the system. Therefore, a lower sensitivity setting is more sensitive to disconnect detection than a higher sensitivity setting. However, those skilled in the art will understand that the sensitivity setting can be configured in other ways such that a higher sensitivity setting is more sensitive to disconnect detection than a lower sensitivity setting.

[0441] In some forms, the sensitivity setting can be set as the default sensitivity setting based on one or more of the air circuit configuration, the type of patient interface, or the patient type. In other forms, the default sensitivity setting can be set based on analysis of previous sensitivity data stored in memory from previous treatment periods or previous learning periods.

[0442] Figures 7C to 7E Exemplary test phases for the same patient circuit configuration under identical conditions but with different sensitivity setpoints are disclosed. The patient circuit comprises a single-branch circuit with a patient interface mask for use by adult patients. In these tests, circuit disconnection occurred between 52 and 74 seconds, and high leakage occurred between 96 and 153 seconds. The transient conductivity value (G) needs to be maintained above a conductivity threshold for a predetermined time limit, such as at least 5 consecutive breaths, to generate a disconnection event response, such as an alarm or message. Figures 7C to 7E In each of these, the top recording line shows the change in instantaneous conductivity (G) over time in seconds, while the bottom recording line shows the changes in instantaneous pressure (Pm) 7108 and instantaneous flow rate (Qt) 7106 over time in seconds.

[0443] Figure 7CThe test is illustrated with a conductivity threshold 7050 set as indicated by the dashed line on the conductivity trace at 15% sensitivity setting. As indicated at 7052 and 7056, when the instantaneous conductivity (G) exceeds the conductivity threshold 7050, a timer begins counting to assess whether the instantaneous conductivity continuously exceeds the threshold for a predetermined time limit as indicated by arrow 7064. After the predetermined time limit 7064 is exceeded, a disconnection event response 7054 is initiated, which may include activating a message or alarm during this time. However, a disconnection event can be detected whenever the instantaneous conductivity exceeds the conductivity threshold 7050, as indicated by the points provided along the conductivity threshold dashed line. A single disconnection event (i.e., a single point) will not generate a disconnection event response 7054. When the loop is reconnected, the instantaneous conductivity value drops below the conductivity threshold at point 7060, and the disconnection event response is aborted; that is, the message or alarm is deactivated. The shaded block indicated by arrow 7058 also indicates that the instantaneous conductance continuously exceeds the disconnection threshold 7050 for a period exceeding a predetermined time limit 7064, generating a disconnection event response, such as generating a message or alarm. However, in block 7058, a disconnection event is falsely detected when a high leakage event occurs without a loop disconnection, thus falsely indicating a loop disconnection. Therefore, the disconnection threshold is too sensitive, necessitating an increase in the sensitivity setting to reduce sensitivity and prevent false indications of loop disconnection events. Pressure 7108 and flow 7106 recording lines are provided in the lower recording line and indicate that a loop disconnection occurred between 52 and 74 seconds when the recurrent respiratory flow recording line 7106 was no longer present. However, the recurrent respiratory flow recording line 7106 remained present between 96 and 153 seconds, indicating that the patient continued to breathe on the patient circuit.

[0444] exist Figure 7DIn this context, the sensitivity setting has been increased to 35% to reduce the sensitivity of the conductivity threshold 7050. As described above, the instantaneous conductivity exceeds the conductivity threshold 7050 at point 7052 and continues to exceed the conductivity threshold for a predetermined time limit 7064, thereby causing a disconnection event response 7054. As described above, a disconnection event can be detected whenever the instantaneous conductivity exceeds the conductivity threshold 7050a, as indicated by the points provided along the conductivity threshold dashed line 7050. The disconnection event response 7054 includes activating a message or alarm to indicate a loop disconnection event when a disconnection indication is continuously detected for a predetermined time limit. When the loop is reconnected, the instantaneous conductivity value drops below the conductivity threshold at point 7060, and the disconnection event response is aborted, i.e., the message or alarm is deactivated. The instantaneous conductivity threshold 7050 is exceeded again at 7056, but not continuously for the predetermined time limit, because the instantaneous conductivity drops below the conductivity threshold at 7060, thus not causing a disconnection event response, i.e., no alarm or message is activated. However, due to the high leakage event, the instantaneous conductivity value again exceeds the conductivity threshold at 7062 and remains above the conductivity threshold for a predetermined time limit 7064, resulting in a second disconnection event response (e.g., activation of a message or alarm), thereby indicating a loop disconnection event in block 7058. However, as mentioned above, this is a false detection of a loop disconnection event caused by high leakage rather than an actual disconnection of the loop. Therefore, if high leakage occurs, the 35% sensitivity setting may still provide some false disconnection indication.

[0445] exist Figure 7E In this scenario, the sensitivity setting has been further increased to 45% to further reduce the sensitivity of the conductivity threshold 7050 in an attempt to prevent false disconnection event detection. As described above, the instantaneous conductivity exceeds the conductivity threshold 7050 at point 7052 and continues to exceed the conductivity threshold for a predetermined time limit 7064, thereby triggering a disconnection event response 7054. The disconnection event response 7054 provides a message or alarm to indicate the occurrence of a loop disconnection event. When the loop is reconnected, the instantaneous conductivity value drops below the conductivity threshold at point 7060, and the disconnection event response is aborted, i.e., the message or alarm is deactivated. The instantaneous conductivity threshold 7050 is exceeded again at points 7056 and 7062, as indicated by the points on the dashed disconnection threshold line 7050, but is only less than the predetermined time limit 7064 for a brief period before the instantaneous conductivity falls back below the conductivity threshold at 7060, thus not triggering a disconnection event response, i.e., no alarm or message is activated. This suggests that, for this instance, the most suitable sensitivity setting for this patient circuit configuration would be 45% or more to avoid misdetecting high leakage events as circuit disconnection events.

[0446] In some forms of this technology, a loop disconnection detection system may include disconnection mitigation to increase the likelihood of correctly activating a disconnection alarm or message. This mitigation may be performed after an initial disconnection event is detected, for example, by monitoring transient disconnection parameters for comparison with a disconnection threshold or with a distribution map indicating a passively disconnected loop. Disconnection mitigation may include detecting features that confirm a disconnection event or identifying false detections.

[0447] False disconnect relief, such as for disqualifying a previously / simultaneously detected disconnection event, may include detecting one or more of the following respiratory indicators that instruct the patient to remain connected to the patient circuit:

[0448] • Expiratory flow rate indicating expiratory effort;

[0449] • The inspiratory flow rate that indicates the effort required to inhale;

[0450] • The difference between the instantaneous disconnection parameter calculated during the inspiratory phase and the instantaneous disconnection parameter calculated during the expiratory phase of the respiratory cycle;

[0451] • Negative instantaneous disconnection parameter during the expiratory phase, i.e., negative respiratory flow (Qr) or negative pressure detected in the patient interface (Pm) during the expiratory phase; or

[0452] • The variance of the instantaneous disconnect parameter is compared with the variance of its previous value, which is calculated based on long-term measurements of the instantaneous disconnect parameter value immediately preceding the same phase (i.e., from the inspiratory or expiratory phase). Long-term measurements are based on a predetermined time constant, such as 30 to 300 seconds, 60 to 120 seconds, a predetermined number of breathing phases, or some other time constraint.

[0453] In the case of determining multiple transient disconnection parameters within each respiratory phase, the variation between these transient disconnection parameters within the respiratory phase can indicate "active" load (i.e., patient activity) and serve as a condition for rejecting false disconnection indications.

[0454] If one or more of the above false disconnect mitigation measures are detected after a loop disconnect event is detected, the loop disconnect event is identified as false, and the disconnect indication (Disc) is set to False.

[0455] Confirming disconnect mitigation may include detecting outflow exceeding a predetermined threshold, such as flow rates associated with extreme leaks or flow rates associated with fluid dispersion within the loop or humidifier.

[0456] The type of disconnection relief that can be utilized may depend on the patient circuit being used.

[0457] In some forms, the RPT device can be configured to detect reconnection to the patient circuit. In response to detecting reconnection, the RPT device can be configured to perform one or more of the following: restart treatment, abort a disconnection event response, and generate different responses to reconnection. A reconnection event can be detected by comparing a transient disconnection parameter to a reconnection threshold to indicate a change in the circuit disconnection state or a false disconnection indication. In another form, a reconnection event can be detected by detecting a change in a transient disconnection parameter within a respiratory cycle to indicate that the patient is breathing on the patient circuit.

[0458] Alternatively, a reconnection event can be detected by a mutation in the transient disconnect parameter, indicating the restoration of the patient's presence at the patient interface, during inhalation, exhalation, or closure of the patient interface. The required change in the transient disconnect parameter can be based on an increase or decrease in the transient disconnect parameter satisfying a second threshold or on the discontinuity of the transient disconnect parameter over time. For example, when using impedance, an increase in transient disconnect impedance above a second impedance threshold can signal a trigger for respiration. Alternatively, when using conductivity, a decrease in transient disconnect conductivity below a second conductivity threshold can signal a trigger for respiration.

[0459] A reconnection event can be indicated after activating a disconnection alarm or message, after detecting a single reconnection, or after multiple reconnection detections. The length of time prior to detecting a true disconnection event can be used as a basis for determining the response rate to a reconnection. In other forms, the response rate to a reconnection can be determined based on the patient circuit.

[0460] Treatment using conductivity or impedance monitoring

[0461] While the previously discussed methods are implemented to detect disconnection / reconnection events distinct from high-leakage events, in an alternative form of fault detection method 4340, conductivity or impedance values ​​can be used to detect the occurrence of a specific respiratory event within the system. In one such form, conductivity or impedance values ​​can be used to detect obstruction and optionally activate an alarm or message. Changes in conductivity or impedance over time can be monitored and compared to a recent baseline during treatment. The recent baseline can include determining a short-term average of conductivity or impedance values ​​over time, such as within 2–10 seconds or 2–10 breaths. For example, a constant conductivity nominally zero (or consistently excessive impedance) would indicate complete obstruction somewhere in the patient circuit or patient airway. Alternatively, a value associated with total obstruction can be derived relative to a recent baseline conductivity (or impedance) measurement. Using conductivity or impedance provides a configuration-free means of detecting obstruction that is consistent across treatment modes and can be automatic and always available.

[0462] In other forms of fault detection method 4340, conductivity or impedance values ​​can be used to detect “flow starvation” in a patient. Flow starvation can occur in spontaneously breathing patients ventilated in volume-targeted mode. This occurs if the configured peak inspiratory flow rate does not meet the patient’s inspiratory needs. Flow starvation causes the patient to attempt to draw more flow from the RPT device and circuit than the ventilator can or will supply, resulting in a decrease in airway pressure. This “drawing” can be seen as an abnormally high conductivity value compared to a recent baseline conductivity value, or as a specific distribution pattern during inspiration (e.g., higher conductivity in the early to mid-inspiratory phase than at the end of inspiration). As described above, an abnormally high conductivity value indicating flow starvation will be detected when the patient’s circuit connection is confirmed by detection of conductivity changes within the respiratory cycle or other false disconnection relief detection.

[0463] In some of these forms, the conductivity value during the inspiratory phase can be compared with a third conductivity threshold, and a flow starvation event can be detected if the instantaneous conductivity value exceeds the third conductivity threshold and inspiratory flow is detected.

[0464] Similarly, a low impedance value compared to a recent baseline impedance value, or an impedance value belonging to a specific profile during inspiratory flow, can signal a flow starvation event. A unique profile during inspiratory flow can include a low impedance value at the start of inspiratory flow, followed by an increase in impedance to a higher level at the end of inspiratory flow. A third impedance threshold can be provided, and a flow starvation event can be detected if an instantaneous impedance value from the inspiratory phase falls below the third threshold and inspiratory flow is detected.

[0465] Upon detecting a flow starvation event, the RPT device can provide an indication to caregivers or clinicians. This indication may be an activation of a message on the output device 4290 or an activation of an alarm. In some forms, the detection of a flow starvation event may lead to adjustments in treatment parameters.

[0466] In other forms of fault detection method 4340, conductivity or impedance values ​​can be used to detect insufficient ventilation. This can be detected as an abnormally low conductivity value compared to a recent baseline conductivity value or an abnormally high impedance value compared to a recent baseline impedance value. As described above, an abnormally low conductivity value indicating insufficient ventilation can be detected when confirming patient circuit connection based on the detection of conductivity changes during the respiratory cycle or other false disconnection relief detections.

[0467] In some of these forms, the conductivity value during the inspiratory phase can be compared to a fourth conductivity threshold, and if the instantaneous conductivity value is below the fourth conductivity threshold, insufficient ventilation can be detected. Alternatively, a fourth impedance threshold can be provided, and if the instantaneous impedance value exceeds the fourth impedance threshold, insufficient ventilation can be detected.

[0468] When insufficient ventilation is detected, the RPT device can provide instructions to caregivers or clinicians. These instructions may include activating a message or alarm on the output device 4290. In some versions, detecting insufficient ventilation may lead to adjustments in treatment parameters.

[0469] In other forms of fault detection method 4340, conductivity or impedance values ​​can be provided to detect inappropriate rise time or peak inspiratory flow (PIF) settings, consistent with the significant effort a patient expends during periods when they typically require emptying their lungs. Conductivity or impedance can be calculated continuously throughout the respiratory cycle. A high conductivity or low impedance value at the beginning of inspiration, compared to the conductivity or impedance value at the end of inspiration, can indicate an inappropriate rise time or peak inspiratory flow (PIF) setting. The conductivity or impedance value at the beginning of inspiration can be compared to the conductivity or impedance value at the end of inspiration, and adjustments to the rise time or PIF setting can be provided based on the level of the difference.

[0470] Humidifier

[0471] Humidifier Overview

[0472] In one form of this technology, a humidifier 5000 is provided (e.g., such as...). Figure 5A (As shown), to change the absolute humidity of the air or gas used to deliver to the patient relative to ambient air. Typically, the humidifier 5000 is used to increase the absolute humidity of the airflow and increase the temperature of the airflow (relative to ambient air) before it is delivered to the patient's airway.

[0473] The humidifier 5000 may include a humidifier reservoir 5110, a humidifier inlet 5002 for receiving airflow, and a humidifier outlet 5004 for delivering humidified airflow. In some forms, such as Figure 5A and Figure 5B As shown, the inlet and outlet of the humidifier reservoir 5110 can be a humidifier inlet 5002 and a humidifier outlet 5004, respectively. The humidifier 5000 may also include a humidifier base 5006, which is adapted to receive the humidifier reservoir 5110 and includes a heating element 5240.

[0474] Mechanical components of a humidifier

[0475] Water storage tank

[0476] According to one arrangement, the humidifier 5000 may include a water reservoir 5110 configured to maintain or retain a volume of liquid (e.g., water) for evaporation to humidify the airflow. The water reservoir 5110 may be configured to maintain a predetermined maximum water volume to provide adequate humidification for at least the duration of a respiratory pressure therapy session, such as one night of sleep. Typically, the reservoir 5110 is configured to hold several hundred milliliters of water, for example, 300 ml, 325 ml, 350 ml, or 400 ml. In other forms, the humidifier 5000 may be configured to receive a water supply from an external water source, such as a building's water supply system.

[0477] According to one aspect, the water reservoir 5110 is configured to increase the humidity of an airflow from the RPT device 4000 as airflow passes through it. In one form, the water reservoir 5110 may be configured to facilitate the airflow's travel in a curved path through the reservoir 5110 while in contact with the water volume therein.

[0478] According to one form, the storage 5110 can, for example, be along such a path. Figure 5A and Figure 5B The lateral direction shown is removed from the humidifier 5000.

[0479] The reservoir 5110 may also be configured to prevent liquid from flowing out of it, such as through any hole and / or between its sub-components, when the reservoir 5110 is displaced and / or rotated from its normal operating direction. Since the airflow to be humidified by the humidifier 5000 is typically pressurized, the reservoir 5110 may also be configured to prevent loss of pneumatic pressure due to leakage and / or flow resistance.

[0480] Conductive part

[0481] According to one arrangement, the reservoir 5110 includes a conductive portion 5120 configured to allow efficient heat transfer from the heating element 5240 to the liquid volume within the reservoir 5110. In one form, the conductive portion 5120 may be arranged as a plate, but other shapes are equally applicable. All or part of the conductive portion 5120 may be made of a thermally conductive material, such as aluminum (e.g., with a thickness of approximately 2 mm, such as 1 mm, 1.5 mm, 2.5 mm, or 3 mm), another thermally conductive metal, or some plastics. In some cases, suitable thermal conductivity may be achieved using materials with appropriate geometries and lower thermal conductivity.

[0482] Humidifier reservoir base

[0483] In one embodiment, the humidifier 5000 may include a humidifier reservoir base 5130 (e.g., Figure 5BAs shown, it is configured to receive humidifier reservoir 5110. In some arrangements, humidifier reservoir base 5130 may include locking mechanisms, such as locking lever 5135 configured to retain reservoir 5110 in humidifier reservoir base 5130.

[0484] Water level indicator

[0485] Humidifier reservoir 5110 may include, for example Figures 5A-5B The water level indicator 5150 is shown. In some forms, the water level indicator 5150 may provide a user (such as a patient 1000 or a caregiver) with one or more indications regarding the amount of water in the humidifier reservoir 5110. The one or more indications provided by the water level indicator 5150 may include an indication of the maximum predetermined volume of water, any portion thereof, such as 25%, 50%, 75%, or a volume such as 200 ml, 300 ml, or 400 ml.

[0486] Humidifier electrical & thermal components

[0487] The humidifier 5000 may include several electrical and / or thermal components, such as those listed below.

[0488] Humidifier converter

[0489] The humidifier 5000 may include one or more humidifier converters (sensors) 5210, in addition to or replacing the converter 4270 described above. For example... Figure 5C As shown, the humidifier converter 5210 may include one or more of an air pressure sensor 5212, an air flow converter 5214, a temperature sensor 5216, or a humidity sensor 5218. The humidifier converter 5210 may generate one or more output signals that can communicate with a controller (such as a central controller 4230 and / or a humidifier controller 5250). In some forms, the humidifier converter may be externally located to the humidifier 5000 (such as in the air circuit 4170) when communicating the output signal to the controller.

[0490] Pressure converter

[0491] In addition to or in addition to the pressure sensor 4128 provided in the RPT device 4000, one or more pressure converters 5212 may be provided to the humidifier 5000.

[0492] 4.5.3.1.2 Flow Converter

[0493] In addition to or in addition to the flow sensor 4130 provided in the RPT device 4000, one or more flow converters 5214 may be provided to the humidifier 5000.

[0494] Temperature converter

[0495] The humidifier 5000 may include one or more temperature transducers 5216. The one or more temperature transducers 5216 may be configured to measure one or more temperatures, such as the temperature of the heating element 5240 and / or the temperature of the airflow downstream of the humidifier outlet 5004. In some forms, the humidifier 5000 may further include a temperature sensor 5216 for detecting the ambient air temperature.

[0496] Humidity converter

[0497] In some forms, the humidifier 5000 may include one or more humidity sensors 5218 for detecting the humidity of a gas, such as ambient air. In some forms, the humidity sensor 5218 may be positioned toward the humidifier outlet 5004 to measure the humidity of the gas delivered from the humidifier 5000. The humidity sensor may be an absolute humidity sensor or a relative humidity sensor.

[0498] heating element

[0499] In some cases, heating element 5240 may be provided to humidifier 5000 to provide heat input to one or more water volumes in humidifier reservoir 5110 and / or to airflow. Heating element 5240 may include heating components, such as resistive electric heating rails. A suitable example of heating element 5240 is a layered heating element, such as the layered heating element described in PCT patent application publication number WO2012 / 171072, which is incorporated herein by reference in its entirety.

[0500] In some configurations, the heating element 5240 may be housed within the humidifier base 5006, such as... Figure 5B The heat shown can be supplied to the humidifier reservoir 5110 primarily through conduction.

[0501] Humidifier controller

[0502] According to one arrangement of this technology, such as Figure 5C The humidifier 5000 shown may include a humidifier controller 5250. In one embodiment, the humidifier controller 5250 may be part of a central controller 4230. In another embodiment, the humidifier controller 5250 may be a standalone controller that can communicate with the central controller 4230.

[0503] In one embodiment, the humidifier controller 5250 may receive, for example, measurements of characteristics (such as temperature, humidity, pressure, and / or flow rate) of airflow and water flow in the reservoir 5110 and / or humidifier 5000 as input. The humidifier controller 5250 may also be configured to execute or implement humidifier algorithms and / or deliver one or more output signals.

[0504] like Figure 5C As shown, the humidifier controller 5250 may include one or more controllers, such as a central humidifier controller 5251, a heating air circuit controller 5254 configured to control the temperature of the heating air circuit 4171, and / or a heating element controller 5252 configured to control the temperature of the heating element 5240.

[0505] respiratory waveform

[0506] Figure 6A A model of a typical breathing waveform in an adult during sleep is shown. The horizontal axis represents time, and the vertical axis represents respiratory flow. Although parameter values ​​may vary, typical breathing may have the following approximations: tidal volume, Vt, 0.5 L; inspiratory time, Ti, 1.6 s; peak inspiratory flow rate, Q-peak, 0.4 L / s; expiratory time, Te, 2.4 s; peak expiratory flow rate, Q-peak, -0.5 L / s. The total duration of breathing, Ttot, is approximately 4 s. A person typically breathes at a rate of 15 breaths per minute (BPM), with a ventilatory rate of approximately 7.5 L / min. The typical duty cycle, the ratio of Ti to Ttot, is approximately 40%.

[0507] Figure 6B The patient, during non-REM sleep, typically breathes approximately 34 times in about 90 seconds, treated with an automated PAP, and the mask pressure is approximately 11 cmH2O. The top channel displays a pulse oximetry (SpO2) reading, with a scale ranging from 90% to 99% saturation in the vertical direction. Throughout the period shown, the patient maintains approximately 95% saturation. The second channel shows a quantitative respiratory airflow, ranging from -1 to +1 LPS in the vertical direction, with inspiration being positive. Chest and abdominal movements are shown in the third and fourth channels.

[0508] Vocabulary

[0509] To achieve the purposes of this technical disclosure, one or more of the following definitions may be applied in certain forms of this technology. Alternative definitions may be applied in other forms of this technology.

[0510] General Rules

[0511] Air: In some forms of this technology, air may be considered to mean atmospheric air, and in other forms of this technology, air may be considered to mean some other combination of breathable gases, such as oxygen-rich atmospheric air.

[0512] Environment: In some forms of this technology, the term environment may have the following meanings: (i) outside the treatment system or the patient, and (ii) directly surrounding the treatment system or the patient.

[0513] For example, relative to the environment of the humidifier humidity This could be the humidity of the air directly surrounding the humidifier, such as the humidity inside the patient's sleeping room. This ambient humidity can differ from the humidity outside the patient's sleeping room.

[0514] In another instance, the environment pressure It can be pressure directly around the body or pressure outside the body.

[0515] In some forms, ambient (e.g., acoustic) noise can be considered as the background noise level in the patient's room, excluding noise generated by, for example, the RPT device or from the mask or patient interface. Ambient noise can be generated by sound sources outside the room.

[0516] Automated positive airway pressure (APAP) therapy: CPAP therapy in which the treatment pressure is automatically adjusted between a minimum and a maximum, for example, varying with each breath, depending on the presence of an indication of an SBD event.

[0517] Continuous positive airway pressure (CPAP) therapy: In this therapy, the treatment pressure can be approximately constant throughout the patient's respiratory cycle. In some forms, the pressure at the airway inlet will be slightly higher during expiration and slightly lower during inspiration. In other forms, the pressure will vary between different respiratory cycles, for example, increasing in response to an indication of partial upper airway obstruction and decreasing in response to the absence of such an indication.

[0518] Flow rate: The volume or mass of air or gas delivered per unit time. The flow rate as volume per unit time may be specifically referred to as "volumetric flow rate"; in this disclosure, it is the quantity represented by the unrestricted term "flow rate". Flow rate can refer to an instantaneous quantity. In some cases, the reference to flow rate will be to a scalar quantity, i.e., a quantity having only magnitude. In other cases, the reference to flow rate will be to a vector quantity, i.e., a quantity having both magnitude and direction. Flow rate can be given by the notation Q. 'Flow rate' is sometimes simply abbreviated as 'flow'.

[0519] In the context of patient breathing, flow rate can be nominally positive for the inspiratory portion of the patient's respiratory cycle and therefore negative for the expiratory portion. Total flow rate Qt is the airflow exiting the RPT device. Tidal flow rate Qv is the airflow exiting the ventilator to allow flushing of exhaled air. Leakage flow rate Ql is the leakage flow rate from the patient interface system. Respiratory flow rate Qr is the airflow received into the patient's respiratory system.

[0520] Noise, conducted (acoustic): In this document, conducted noise refers to noise delivered to the patient through pneumatic pathways, such as air circuits and patient interfaces, 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.

[0521] Noise, radiated (acoustic): Radiated noise in this document refers to noise delivered to the patient through the surrounding air. In one form, radiated noise can be quantified by measuring the sound power / pressure level of the object under discussion according to ISO 3744.

[0522] Noise, ventilation (acoustic): Ventilation noise in this document refers to the noise generated by the flow of air through any ventilation opening (such as a ventilation opening for a patient interface).

[0523] Patient: A person, whether or not they have a respiratory illness.

[0524] Pressure is the force per unit area. Pressure can be expressed in units (including cmH2O, gf / cm²). 2 The range of (and hectopascals). 1 cmH2O equals 1 g-f / cm 2 It is approximately 0.98 hectopascals. In this specification, unless otherwise stated, pressure is given in cmH2O.

[0525] The pressure in the patient interface is given by the symbol Pm, while the treatment pressure is given by the symbol Pt, which represents the target value obtained at the current moment through the mask pressure Pm.

[0526] Respiratory pressure therapy (RPT): Applying air supply to the airway inlet at a therapeutic pressure that is typically positive relative to the atmosphere.

[0527] Aspects of the respiratory cycle

[0528] Apnea: According to some definitions, apnea is considered to occur when the flow rate drops below a predetermined threshold for a sustained period of time (e.g., 10 seconds). Obstructive apnea is considered to occur when some obstruction of the airway prevents airflow even with patient effort. Central apnea is considered to occur when apnea is detected due to reduced or absent respiratory effort, even though the airway is patent. Mixed apnea is considered to occur when reduced or absent respiratory effort occurs simultaneously with airway obstruction.

[0529] Respiratory rate: The rate at which a patient breathes spontaneously, usually measured in breaths per minute.

[0530] Duty cycle: The ratio of inspiratory time Ti to total respiratory time Ttot.

[0531] Effort (breathing): The work accomplished by a person who breathes spontaneously by attempting to breathe.

[0532] The expiratory portion of the respiratory cycle: the time period from the start of expiratory flow to the start of inspiratory flow.

[0533] Flow restriction: Flow restriction is considered a state of breathing in which increased effort by the patient does not result in a corresponding increase in flow. Flow restriction occurring during the inspiratory portion of the respiratory cycle can be described as inspiratory flow restriction. Flow restriction occurring during the expiratory portion of the respiratory cycle can be described as expiratory flow restriction.

[0534] Types of flow-limited inhalation waveforms:

[0535] (i) Flattened: It has an upward movement, followed by a relatively flat section, and then a downward movement.

[0536] (ii) M-shape: has two local peaks, one at the leading edge and one at the trailing edge, and a relatively flat section between the two peaks.

[0537] (iii) Chair-shaped: It has a single local peak at the leading edge, followed by a relatively flat section.

[0538] (iv) Inverted chair shape: with a relatively flat section followed by a single local peak at the trailing edge.

[0539] Insufficient breathing: Preferably, insufficient breathing is considered as a reduction in flow rate, rather than a cessation of flow rate. In one form, insufficient breathing can be considered to have occurred when the flow rate drops below a threshold and persists for a period of time. Central insufficient breathing is considered to have occurred when insufficient breathing is detected due to a reduction in respiratory effort. In one form for adults, any of the following can be considered insufficient breathing:

[0540] (i) The patient’s respiratory rate decreases by 30% for at least 10 seconds plus a related 4% desaturation; or

[0541] (ii) The patient’s breathing is reduced (but less than 50%) for at least 10 seconds, accompanied by at least 3% desaturation or arousal.

[0542] Hyperventilation: Increased airflow to above normal levels.

[0543] The inspiratory portion of the respiratory cycle: The time period from the start of inspiratory flow to the start of expiratory flow is considered the inspiratory portion of the respiratory cycle.

[0544] Airway openness: The degree to which the airway is open or the extent to which the airway is open. An open airway is an open airway. Airway openness can be quantified, for example, with a value (1) for open and a value of zero (0) for closed (obstructed).

[0545] Positive end-expiratory pressure (PEEP): Pressure above atmospheric pressure present in the lungs at the end of expiration.

[0546] Peak flow (Q peak): The maximum flow rate during the inspiratory portion of the respiratory flow waveform.

[0547] Tidal volume (Vt): The volume of air inhaled or exhaled during normal breathing without additional effort.

[0548] (Inspiratory) time (Ti): The duration of the inspiratory portion of the respiratory flow waveform.

[0549] (Exhalation) Time (Te): The duration of the expiratory portion of the respiratory flow waveform.

[0550] (Total) Time (Ttot): The total duration between the start of the inspiratory portion of a respiratory flow waveform and the start of the inspiratory portion of a subsequent respiratory flow waveform.

[0551] Typical recent ventilation: The ventilation value that tends to cluster around its recent values ​​within a predetermined time range, which is a measure of the central tendency of recent ventilation values.

[0552] Upper airway obstruction (UAO): This includes partial and complete upper airway obstruction. This may be associated with a state of flow restriction, where the flow rate increases only slightly or even decreases as the pressure differential across the upper airway increases (Starling flow resistor behavior).

[0553] Ventilation: A measurement of the rate at which gases are exchanged by a patient's respiratory system. A measurement of ventilation can include one or both of inspiratory and expiratory flow rates (per unit of time). When expressed as volume per minute, this quantity is often referred to as "minute ventilation." Minute ventilation is sometimes simply given as volume and understood as volume per minute.

[0554] RPT device parameters

[0555] Leakage: The word "leakage" is considered to refer to undesirable airflow. In one instance, leakage can occur due to an incomplete seal between the mask and the patient's face. In another instance, leakage can occur in a bend in the conduit leading to the surrounding environment.

[0556] Terminology for ventilators

[0557] Adaptive Servo Ventilator (ASV): A servo ventilator with a variable rather than a fixed target ventilation. The variable target ventilation can be determined from some characteristics of the patient, such as the patient's breathing characteristics.

[0558] Standby rate: A parameter of the ventilator that determines the minimum respiratory rate (usually measured in breaths per minute) that the ventilator will deliver to the patient if not triggered by spontaneous breathing effort.

[0559] Cyclic: Termination of the inspiratory phase of a ventilator. When a ventilator delivers breaths to a spontaneously breathing patient, the ventilator cycle is considered to end at the end of the inspiratory phase of the respiratory cycle.

[0560] Positive Expiratory Airway Pressure (EPAP): The base pressure to which the pressure changes within the respiratory tract are added to produce the desired mask pressure that the ventilator will attempt to achieve at a given time.

[0561] End-expiratory pressure (EEP): The desired mask pressure that the ventilator attempts to achieve at the end of the expiration phase. If the pressure waveform template (Φ) is zero at the end of expiration, i.e., Π(Φ) = 0, then EEP equals EPAP when Φ = 1.

[0562] Inspiratory positive airway pressure (IPAP): The maximum desired mask pressure that the ventilator attempts to achieve during the inspiratory phase of breathing.

[0563] Pressure support: A number indicating the increase in pressure during inspiration that exceeds the pressure during expiration, and generally refers to the pressure difference between the maximum pressure during inspiration and the baseline pressure (e.g., PS = IPAP - EPAP). In some cases, pressure support refers to the difference the ventilator is designed to achieve, rather than the difference it actually achieves.

[0564] Servo ventilator: A ventilator that measures a patient's ventilation volume, has a target ventilation volume, and adjusts the level of pressure support to enable the patient to achieve the target ventilation volume.

[0565] Spontaneous / Timed (S / T): A mode of operation for a ventilator or other device that attempts to detect the onset of spontaneous breathing in a patient. However, if the device fails to detect breathing within a predetermined time period, it will automatically initiate the delivery of breaths.

[0566] Oscillation: A term equivalent to pressure support.

[0567] Triggered: When the ventilator delivers breathing air to a patient who is breathing spontaneously, it is considered to be triggered by the patient's effort at the beginning of the breathing portion of the respiratory cycle.

[0568] Typical recent ventilation: Typical recent ventilation (Vtyp) is the value around which recent ventilation measurements tend to cluster within a predetermined time range. For example, a measure of the central tendency of recent historical ventilation measurements can be a suitable value for typical recent ventilation.

[0569] Ventilator: A mechanical device that provides pressure support to a patient to perform some or all of the breathing work.

[0570] Anatomical structure of the respiratory system

[0571] Diaphragm: A muscular plate that extends across the bottom of the ribcage. The diaphragm separates the thoracic cavity, which contains the heart, lungs, and ribs, from the abdominal cavity. As the diaphragm contracts, the volume of the thoracic cavity increases and air is drawn into the lungs.

[0572] The larynx: The larynx or larynx contains the vocal cords and connects the lower part of the pharynx (hypopharynx) to the trachea.

[0573] Lungs: The human respiratory organ. The conduction area of ​​the lungs includes the trachea, bronchi, bronchioles, and terminal bronchioles. The respiratory area includes the respiratory bronchioles, alveolar ducts, and alveoli.

[0574] Nasal cavity: The nasal cavity (or nasal socket) is a large, air-filled space located in the middle of the face above and behind the nose. It is divided into two parts by a vertical wing called the nasal septum. On the sides of the nasal cavity are three horizontal branches called nasal conchae (singular "concha"). The front of the nasal cavity is the nasal part, while the back connects to the nasopharynx via the internal nasal openings.

[0575] Pharynx: The part of the throat located just below the nasal cavity and above the esophagus and larynx. The pharynx is conventionally divided into three segments: the nasopharynx (hyperpharynx) (the nasal part of the pharynx), the oropharynx (middle pharynx) (the oral part of the pharynx), and the laryngopharynx (hypopharynx).

[0576] Material

[0577] Silicone resin or silicone elastomer: synthetic rubber. In this specification, reference to silicone resin refers to liquid silicone rubber (LSR) or molding silicone rubber (CMSR). One commercially available form of LSR is SILASTIC (included in the range of products sold under this trademark), manufactured by Dow Corning. Another manufacturer of LSR is Wacker Chemie. 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 using ASTM D2240.

[0578] Polycarbonate: Typically a transparent thermoplastic polymer of bisphenol A carbonate.

[0579] Terminology related to the use of mechanical articles

[0580] Resilience: The ability of a material to absorb energy during elastic deformation and release energy during release.

[0581] • 'Resilient': When de-energized, it releases virtually all of its energy. This includes, for example, certain silicones and thermoplastic elastomers.

[0582] Hardness: The ability of a material to resist deformation (e.g., as described by Young's modulus, or an indentation hardness scale measured on a standard sample size).

[0583] • 'Soft' materials may include silicone or thermoplastic elastomers (TPEs) and may be easily deformed, for example, under finger pressure.

[0584] · 'Hard' materials can include polycarbonate, polypropylene, steel or aluminum, and can be, for example, not easily deformed under finger pressure.

[0585] 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 moment, such as compression, tension, bending, or torsion. A structure or component can provide different resistances in different directions.

[0586] • 'Soft' structures or components: Structures or components that will change shape, such as bending, when subjected to a relatively short period of time, such as 1 second, to support their own weight.

[0587] • 'Rigid' structures or components: Structures or components that will not substantially change shape when subjected to the loads typically encountered during use. An example of this use could be setting up and maintaining a patient interface in a sealed relationship with the inlet of the patient's airway, for example, under a load of approximately 20 to 30 cm H2O pressure.

[0588] As an example, an I-beam can exhibit different flexural stiffness (resistance to bending loads) in the first direction compared to the second orthogonal direction. In another example, the structure or component is flexible in the first direction and rigid in the second direction.

[0589] Other notes

[0590] This patent document contains a portion of copyrighted material. The copyright holder does not object to the reproduction of this patent document or patent disclosure by any person in the form it appears in the patent office documents or records, but otherwise reserves all copyright rights.

[0591] Unless explicitly stated in the context and a numerical range is provided, it should be understood that every intermediate value between the upper and lower limits of the range, up to one-tenth of the lower limit unit, and any other value or intermediate value within the range are broadly included within this technique. The upper and lower limits of these intermediate ranges may be included independently within the intermediate range and within the scope of this technique, but are subject to any explicitly excluded boundaries within the range. Where the range includes one or both of the extreme values, this technique also includes ranges that exclude any one or both of those included extreme values.

[0592] Furthermore, where one or more values ​​described herein are implemented as part of this technique, it should be understood that such values ​​may be approximate unless otherwise stated, and such values ​​may be used to the extent permitted or required by the practical implementation of the technique for any appropriate valid digits.

[0593] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this technology pertains. Although any methods and materials similar to or equivalent to those described herein may be used in the practice or testing of this technology, a limited number of representative methods and materials are described herein.

[0594] When a particular material is identified for use in configuring a component, an obvious alternative material with similar properties is used as its substitute. Furthermore, unless otherwise stated, any and all components described herein are to be understood as being capable of being manufactured and therefore can be manufactured together or separately.

[0595] It must be noted that, unless the context clearly specifies otherwise, the singular forms “a,” “an,” and “the” used herein and in the appended claims include their plural equivalents.

[0596] All publications mentioned herein are incorporated herein in their entirety by reference to disclose and describe the methods and / or materials that are the subject of those publications. The publications discussed herein are provided only for those published prior to the filing date of this application. Nothing herein should be construed as an admission that the present technology is not entitled to priority of these publications due to prior invention. Furthermore, the publication dates provided may differ from the actual publication dates and may require separate verification.

[0597] The terms “comprises” and “comprising” should be understood as referring to each element, component, or step in a non-exclusive manner, indicating the marked element, component, or step that may be present or utilized, or in combination with other unmarked elements, components, or steps.

[0598] The headings used in the detailed description are for the convenience of the reader only and should not be used to limit the subject matter found in this disclosure or throughout the claims. The headings should not be used to interpret the scope of the claims or to limit the claims.

[0599] Although the present technology has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the present technology. In some cases, terms and symbols may imply specific details not required for the practice of the present technology. For example, although the terms "first" and "second" may be used, they are not intended to indicate any order unless otherwise specified, but rather to distinguish different elements. Furthermore, although process steps in a method may be described or illustrated in a certain order, this order is not necessary. Those skilled in the art will recognize that this order can be modified, and / or aspects of the order may be performed simultaneously or even concurrently.

[0600] Therefore, it should be understood that numerous modifications can be made to the exemplary embodiments described herein, and that other arrangements can be designed without departing from the spirit and scope of the present technology.

[0601] List of reference numerals

[0602] Project Reference Number

[0603] Patient 1000

[0604] Patient Interface 3000

[0605] Sealing Formation Structure 3100

[0606] 3200 air chamber

[0607] Stable structure 3300

[0608] Vent 3400

[0609] Connection port 3600

[0610] Forehead support 3700

[0611] RPT device (or ventilator) 4000

[0612] Outer casing 4012

[0613] Exhaled air inlet port 4014

[0614] Intake / Outtake Port 4016

[0615] 4018 Handle

[0616] Upper housing outer shell 4020

[0617] Base 4021

[0618] Lower housing 4022

[0619] User interface display device 4024

[0620] Alarm indicator light strip 4026

[0621] Button 4028

[0622] 4031 in the exhalation section

[0623] Inhalation section 4033

[0624] Inlet air filter 4034

[0625] Airflow 4035

[0626] Filter assembly 4036

[0627] Inlet seal 4038

[0628] Inlet silencer 4039

[0629] Main seal 4040

[0630] Oxygen supply path 4043

[0631] Grille 4044

[0632] Oxygen flow 4045

[0633] Oxygen connection or inlet port 4046

[0634] Data connection 4047

[0635] Exhalation mask 4048

[0636] Electrical connector 4049

[0637] Latch 4050

[0638] Switch 4051

[0639] Release button 4050R

[0640] Battery cover 4052

[0641] Grip feet 4053

[0642] Oxygen sensor cover 4054

[0643] Pneumatic block 4056

[0644] Speaker 4061

[0645] Oxygen sensor 4064

[0646] Cooling fan 4068

[0647] Export silencer 4084

[0648] Safety valve 4085

[0649] Printed circuit board or PCB 4086

[0650] Main blower 4104

[0651] 4108 volute assembly

[0652] 4113 Outlet air filter

[0653] Check valve assembly 4114

[0654] Electric valve 4116

[0655] Muffler 4118

[0656] Flow control solenoid valve 4120

[0657] Export silencer 4121

[0658] Inlet silencer 4122

[0659] Peep blower 4124

[0660] Pressure sensor 4128

[0661] Flow sensor 4130

[0662] Flow element 4132

[0663] PEEP solenoid valve 4136

[0664] Controllable pressure source device or pressure generator 4140

[0665] Peep pressure sensor 4142

[0666] Oxygen inlet port 4144

[0667] Return valve 4160

[0668] 4170 delivery pipe or air circuit

[0669] Air circuit 4171

[0670] Supplementing oxygen 4180

[0671] Electrical components 4200

[0672] Power Supply 4210

[0673] Input device 4220

[0674] Central controller 4230

[0675] Clock 4232

[0676] Treatment device controller 4240

[0677] Blower 4242

[0678] Electric motor 4244

[0679] Protection circuit 4250

[0680] Memory 4260

[0681] Converter or sensor 4270

[0682] 4276 Motor Speed ​​Converter

[0683] Data communication interface 4280

[0684] Remote external communication network 4282

[0685] Local external communication network 4284

[0686] Remote external device 4286

[0687] Local external device 4288

[0688] Output device 4290

[0689] Display driver 4292

[0690] Monitor 4294

[0691] Algorithm module 4300

[0692] Processing module 4310

[0693] Pressure compensation algorithm 4312

[0694] Ventilation flow rate estimation algorithm 4314

[0695] Leakage flow estimation algorithm 4316

[0696] Respiratory flow estimation algorithm 4318

[0697] Healing Engine Module 4320

[0698] Phase determination algorithm 4321

[0699] Waveform Determination Algorithm 4322

[0700] Algorithm 4323 for determining ventilation volume

[0701] Algorithm 4324 for determining inhalation flow limit

[0702] Algorithm 4325 for determining apnea / hypoventricular hypoventricular activity

[0703] Snoring detection algorithm 4326

[0704] Algorithm 4327 for determining airway occupancy

[0705] Target ventilation determination algorithm 4328

[0706] Treatment parameter determination algorithm 4329

[0707] Treatment control module 4330

[0708] Fault Status Module 4340

[0709] Internal battery 4450

[0710] Humidifier 5000

[0711] Humidifier inlet 5002

[0712] Humidifier outlet 5004

[0713] Humidifier base 5006

[0714] Storage 5110

[0715] Conductive component 5120

[0716] Humidifier reservoir base 5130

[0717] Locking lever 5135

[0718] Water level indicator 5150

[0719] 5210 Humidifier Converter or Sensor

[0720] Pressure transducer or sensor 5212

[0721] Flow converter 5214

[0722] Temperature sensor or converter 5216

[0723] Humidity sensor 5218

[0724] Heating element 5240

[0725] Humidifier controller 5250

[0726] Central humidifier controller 5251

[0727] Heating element controller 5252

[0728] Air circuit controller 5254

[0729] Loop Break Detection Method 7000

[0730] 7000A Circuit Break Detection Method

[0731] Start 7010

[0732] Determine the patient circuit type 7012

[0733] Provide patient information 7013

[0734] Determine the disconnect threshold as 7014

[0735] Test Q and P 7016

[0736] Calculate instantaneous disconnection parameter 7018

[0737] Compare the disconnect parameters with the disconnect threshold 7020

[0738] Check the detected disconnection event 7022

[0739] Set / keep the disconnect indicator to false 7024

[0740] Set / keep the disconnect indicator to true 7026

[0741] Start / Increment Timer 7032

[0742] Is the time greater than or equal to the time limit 7034?

[0743] Reset the timer to zero 7038

[0744] Activate alarm / message 7040

[0745] Conductivity threshold 7050

[0746] Exceeding thresholds 7052, 7056, and 7062

[0747] Disconnection event response 7054

[0748] False disconnection event response 7058

[0749] Drop below the threshold 7060

[0750] Reservation time limit 7064

[0751] Conductivity trigger threshold 7100

[0752] Inhalation phase 7102

[0753] Expiratory phase 7104

[0754] Instantaneous respiratory flow 7106

[0755] Instantaneous airway pressure 7108

[0756] Conductivity trigger point 7110

[0757] Instantaneous conductivity (G) 7112

[0758] Transmittance as a function of time (dG / dt) 7114

[0759] Instantaneous impedance (Z) 7116

[0760] Disconnection point 7118

[0761] Traffic trigger point 7120

[0762] Normal breathing phase 7122

[0763] Disconnection phase 7124

[0764] Pressure trigger point 7130

Claims

1. A respiratory therapy system configured to provide respiratory therapy to a patient breathing during a continuous respiratory cycle including an inspiratory phase and an expiratory phase, the system comprising: A pressure generator configured to supply a pressurized airflow, the pressure generator being configured to be coupled to a patient interface via an air circuit to deliver the pressurized air from the pressure generator to the patient; At least one sensor configured to provide one or more signals indicating the pressure and flow rate of the pressurized airflow; and A controller including a processor, the controller being configured to: Instantaneous pressure and instantaneous flow rates are repeatedly detected based on one or more signals from the at least one sensor; The instantaneous conductivity value is repeatedly calculated based on the instantaneous pressure value and the instantaneous flow rate value; as well as The instantaneous conductivity value is monitored over time to detect the occurrence of respiratory events within the system; The controller is configured to determine the level of difference between an instantaneous conductance value calculated from the beginning of the inhalation phase and an instantaneous conductance value calculated from the end of the inhalation phase, and the controller is configured to adjust the rise time setpoint based on the level of difference.

2. The respiratory therapy system of claim 1, wherein the respiratory event is an obstruction.

3. The respiratory therapy system of claim 2, wherein the obstruction is detected when the instantaneous conductivity value drops below a predetermined threshold.

4. The respiratory therapy system of claim 2, wherein the obstruction is detected when the instantaneous conductivity value remains constant over time.

5. The respiratory therapy system according to any one of claims 2 to 4, wherein the obstruction occurs in the air circuit, the patient interface, or the patient's airway.

6. The respiratory therapy system of claim 1, wherein the respiratory event is flow starvation during volume target mode.

7. The respiratory therapy system of claim 6, wherein the flow starvation is detected as a distribution function of the instantaneous conductance value during the inspiratory phase of the respiratory cycle.

8. The respiratory therapy system of claim 7, wherein the flow hunger is detected when the transient conductivity value of the initial to mid-inspiratory phase of the inspiratory phase is higher than that of the late inspiratory phase.

9. The respiratory therapy system of claim 6, wherein the flow starvation is detected by comparing (a) an instantaneous conductivity value calculated from the inspiratory phase of the respiratory cycle with (b) a conductivity threshold.

10. The respiratory therapy system of claim 9, wherein flow hunger is detected when the instantaneous conductivity value calculated from the inspiratory phase of the respiratory cycle exceeds the conductivity threshold.

11. The respiratory therapy system according to any one of claims 1 to 4 and 6 to 10, wherein upon detection of the respiratory event, the controller is configured to activate a message to indicate the occurrence of the respiratory event.

12. A respiratory therapy system configured to provide respiratory therapy to a patient breathing during a continuous respiratory cycle including an inspiratory phase and an expiratory phase, the system comprising: A pressure generator configured to supply a pressurized airflow, the pressure generator being configured to be coupled to a patient interface via an air circuit to deliver the pressurized air from the pressure generator to the patient; At least one sensor configured to provide one or more signals indicating the pressure and flow rate of the pressurized airflow; and A controller including a processor, the controller being configured to: Instantaneous pressure and instantaneous flow rates are repeatedly detected based on one or more signals from the at least one sensor; The instantaneous conductivity value is repeatedly calculated based on the instantaneous pressure value and the instantaneous flow rate value; as well as The change in the instantaneous conductance value over time is monitored to monitor the respiratory therapy; The controller is configured to determine the level of difference between an instantaneous conductance value calculated from the beginning of the inhalation phase and an instantaneous conductance value calculated from the end of the inhalation phase, and the controller is configured to adjust the rise time setpoint based on the level of difference.

13. The respiratory therapy system of claim 12, wherein the controller is further configured to adjust the peak inspiratory flow rate setpoint based on the difference level.

14. The respiratory therapy system of claim 12, wherein the controller is configured to monitor the instantaneous conductance value over time to determine the inspiratory and expiratory phases of one or more respiratory cycles.

15. The respiratory therapy system of claim 12, wherein the controller is configured to monitor the instantaneous conductivity value over time to detect insufficient ventilation.

16. The respiratory therapy system of claim 15, wherein the controller is configured to detect the insufficient ventilation flow as an abnormally low conductivity value compared to a recent baseline conductivity value.

17. A respiratory therapy system configured to provide respiratory therapy to a patient breathing during a continuous respiratory cycle including an inspiratory phase and an expiratory phase, the system comprising: A pressure generator configured to supply a pressurized airflow, the pressure generator being configured to be coupled to a patient interface via an air circuit to deliver the pressurized air from the pressure generator to the patient; At least one sensor configured to provide one or more signals indicating the pressure and flow rate of the pressurized airflow; and A controller including a processor, the controller being configured to: Instantaneous pressure and instantaneous flow rates are repeatedly detected based on one or more signals from the at least one sensor; The instantaneous impedance value is repeatedly calculated based on the instantaneous pressure value and the instantaneous flow rate value; as well as The instantaneous impedance value is monitored over time to detect the occurrence of respiratory events within the system; The controller is configured to determine the level of difference between an instantaneous impedance value calculated from the beginning of the inhalation phase and an instantaneous impedance value calculated from the end of the inhalation phase, and the controller is configured to adjust the rise time setting based on the level of difference.

18. The respiratory therapy system of claim 17, wherein the respiratory event is an obstruction.

19. The respiratory therapy system of claim 18, wherein the obstruction is detected when the instantaneous impedance value exceeds a predetermined threshold.

20. The respiratory therapy system of claim 18, wherein the obstruction is detected when the instantaneous impedance value remains substantially constant over time.

21. The respiratory therapy system according to any one of claims 18 to 20, wherein the obstruction occurs in the air circuit, the patient interface, or the patient's airway.

22. The respiratory therapy system of claim 17, wherein the respiratory event is flow starvation during volume target mode.

23. The respiratory therapy system of claim 22, wherein the flow starvation is detected as a distribution function of instantaneous impedance values ​​during the inspiratory portion of the respiratory cycle.

24. The respiratory therapy system of claim 23, wherein the flow hunger is detected when the transient impedance value of the early to mid-inspiratory phase of the inspiratory phase is lower than that of the late inspiratory phase.

25. The respiratory therapy system of claim 22, wherein the flow starvation is detected by comparing an instantaneous impedance value calculated from the inspiratory phase of the respiratory cycle with an impedance threshold.

26. The respiratory therapy system of claim 25, wherein flow starvation is detected when the instantaneous impedance value calculated from the inspiratory phase of the respiratory cycle drops below the impedance threshold.

27. The respiratory therapy system according to any one of claims 17 to 20 and 22 to 26, wherein, upon detection of the respiratory event, the controller is configured to provide a message indicating the occurrence of the respiratory event.

28. A respiratory therapy system configured to provide respiratory therapy to a patient breathing during a continuous respiratory cycle including an inspiratory phase and an expiratory phase, the system comprising: A pressure generator configured to supply a pressurized airflow, the pressure generator being configured to be coupled to a patient interface via an air circuit to deliver the pressurized air from the pressure generator to the patient; At least one sensor configured to provide one or more signals indicating the pressure and flow rate of the pressurized airflow; and A controller including a processor, the controller being configured to: Instantaneous pressure and instantaneous flow rates are repeatedly detected based on one or more signals from the at least one sensor; The instantaneous impedance value is repeatedly calculated based on the instantaneous pressure value and the instantaneous flow rate value; and The change in the instantaneous impedance value over time is monitored to monitor the respiratory therapy; The controller is configured to determine the level of difference between an instantaneous impedance value calculated from the beginning of the inhalation phase and an instantaneous impedance value calculated from the end of the inhalation phase, and the controller is configured to adjust the rise time setting based on the level of difference.

29. The respiratory therapy system of claim 28, wherein the controller is further configured to adjust the peak inspiratory flow rate setpoint based on the difference level.

30. The respiratory therapy system of claim 28, wherein the controller is configured to monitor the instantaneous impedance value over time to determine the inspiratory phase and the expiratory phase of each respiratory cycle.

31. The respiratory therapy system of claim 28, wherein the controller is configured to monitor the instantaneous impedance value over time to detect insufficient ventilation.

32. The respiratory therapy system of claim 31, wherein the controller is configured to detect insufficient ventilation as an abnormally high impedance value compared to a recent reference conductivity value.

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