Identification of Acoustic Components for a Respiratory Therapy System

Abstract

A processor associated with the respiratory treatment device (7040) applies acoustic techniques, such as to identify air path components. The device may include a pressure generator configured to generate pressurized air that is supplied from an outlet along an air circuit to a patient interface. The device may include a sensor configured to generate an acoustic signal representative of sound within the air circuit. The device may include a damping structure configured to reduce sound reflections from the flow generator along the air circuit. A processor, such as a controller, may be configured to process the acoustic signal to identify the patient interface and / or the air circuit. This processing may detect and summarize acoustic signatures, such as by matching and averaging, and / or flatten the spectrum of the acoustic signal.

Description

Technical Field

[0001] 1 Cross - reference to related applications This application claims the benefit of Australian Provisional Application No. 2019901502, filed on May 2, 2019. The entire disclosure of this document is incorporated herein by reference and made a part hereof.

[0002] 2 Background of the technology 2.1 Field of the technology This technology relates to one or more of the detection, diagnosis, treatment, prevention, and improvement of respiratory - related diseases. This technology also relates to medical devices or apparatuses and their use. For example, the devices of this technology can provide acoustic technologies for the identification and / or control of components of such devices for the purpose of treatment generation.

Background Art

[0003] 2.2 Description of related technologies 2.2.1 The human respiratory system and its diseases The respiratory system of the body facilitates gas exchange. The nose and mouth form the entrances to the patient's airways.

[0004] These airways include a series of branching tubes that become narrower, shorter, and more numerous as they progress deeper into the lungs. The main function of the lungs is gas exchange, which involves moving oxygen from the inhaled air into the venous blood and moving carbon dioxide in the opposite direction. The trachea divides into the right and left main bronchi, which further divide and ultimately become terminal bronchioles. The bronchi constitute the airways for conduction and are not involved in gas exchange. When the airways further divide, they become respiratory bronchioles and ultimately alveoli. Gas exchange occurs in the alveolar region of the lungs, which is called the respiratory region. See the following: "Respiratory Physiology", by John B. West, Lippincott Williams & Wilkins, 9th edition published 2012.

[0005] There is a range of respiratory diseases. Specific diseases can be characterized by specific onset (e.g., apnea, hypopnea, and hyperventilation).

[0006] Obstructive sleep apnea (OSA) is a respiratory disorder characterized by events such as closure or obstruction of the upper airway during sleep. This is the result of a combination of an abnormally small upper airway and the normal loss of muscle tone in the tongue area, and the normal loss of the soft palate and posterior oropharyngeal wall during sleep. As a result, affected patients typically stop breathing for periods lasting between 30 and 120 seconds, sometimes 200 to 300 times a night. As a result, excessive daytime sleepiness occurs and can cause cardiovascular disease and brain damage. This syndrome is a common disease, particularly common in middle-aged overweight men, but patients have no awareness of the symptoms. See U.S. Patent No. 4,944,310 (Sullivan).

[0007] To treat or improve such conditions, a range of treatments are used. Furthermore, in other respects, healthy individuals can also advantageously utilize preventive treatment for respiratory diseases. However, there are a number of deficiencies in these.

[0008] 2.2.2 Therapy A variety of therapies (e.g., continuous positive airway pressure (CPAP) therapy, high-flow therapy (HFT), non-invasive ventilation (NIV), and invasive ventilation (IV)) are used for the treatment of one or more of the above respiratory diseases.

[0009] 2.2.3 Treatment System These treatments can be provided by a respiratory treatment system or device. Such systems and devices can also be used for diagnosis without treating the disease.

[0010] A respiratory treatment system can include a respiratory treatment device (RT device), an air circuit, a humidifier, a patient interface, and data management.

[0011] 2.2.3.1 Patient Interface The patient interface can be used to provide an interface to a breathing apparatus to a wearer, for example, by providing an airflow to the airway inlet. The airflow can be provided via a mask to the nose and / or mouth, a tube to the mouth, or a tracheotomy tube to the patient's trachea. Depending on the therapy applied, the patient interface can, for example, form a seal with the area of the patient's face, thereby promoting gas delivery at a sufficient distributed pressure along with the atmospheric pressure for therapy execution (e.g., at a positive pressure of about 10 cmH2O relative to the atmospheric pressure). In other treatment modalities such as oxygen delivery, the patient interface may not include a seal sufficient to promote the delivery of gas supply to the airway at a positive pressure of about 10 cmH2O.

[0012] 2.2.3.2 Respiratory Therapy (RT) Devices Respiratory Therapy (RT) devices, such as Respiratory Pressure Therapy (RPT) devices, can be used for the delivery of one or more of the above-described therapies, for example, by generating an air delivery flow to the airway inlet. This airflow can be pressurized. Examples of RPT devices include CPAP devices and ventilators. The Respiratory Therapy (RT) device can, in some cases, be a High-Flow Therapy (HFT) device that provides high-flow respiratory therapy.

[0013] Air pressure generators are known in a wide range of applications (e.g., industrial-scale ventilation systems). However, air pressure generators for medical use have specific requirements that cannot be satisfied by more general air pressure generators (e.g., reliability requirements, size requirements, and weight requirements of medical devices).

[0014] Examples of RPT devices include ventilators such as the ResMed S9 sleep therapy system, the ResMed Stellar® series of adult and pediatric ventilators, and the ResMed Astral® 150 ventilator.

[0015] 2.2.3.3 Humidifier When delivering an air flow without humidification, it can lead to drying of the airway. When a humidifier is used with an RT device and a patient interface, humidified gas is generated, minimizing drying of the nasal mucosa and increasing patient airway comfort. Additionally, in a cooler climate, generally adding warm air to the facial area around the patient interface increases comfort more than in the case of cold air.

[0016] 2.2.3.4 Ventilation technology Some forms of respiratory therapy systems may include a ventilation section for expelling exhaled carbon dioxide. This ventilation section enables gas flow from the internal space (e.g., the plenum chamber) of the patient interface to the outside (e.g., the surroundings) of the patient interface.

[0017] 2.2.3.5 Sensing and data management Patients, caregivers, clinicians, insurance companies, or technicians may wish to collect data related to respiratory therapy, whether it pertains to the patient, to individual components used in the treatment, or to the treatment system as a whole. When providing respiratory therapy to a patient, there are numerous situations in which one or more stakeholders can benefit by collecting treatment-related data and leveraging the collected data.

[0018] In particular, some components of a respiratory therapy system need to be replaced more frequently than other components for effective treatment. For example, a patient interface with a silicone seal-forming part can be replaced by the patient in a few months (e.g., 3 months), while the RT device can be replaced or upgraded every few years (e.g., 3 years). In the case of components that are replaced relatively frequently (e.g., the patient interface), patients or caregivers face challenges in receiving reliable and accurate notifications about component replacement times at low cost. When replacing a component, the patient or caregiver may need to change one or more settings in the therapy system (e.g., software settings in the RT device) so that the therapy system can make the most of the new component. Therefore, the ability to identify the components of a respiratory therapy system is important both for optimizing treatment and for informing patients and caregivers about replacement times.

[0019] To date, various solutions have been adopted or proposed in the field of respiratory therapy regarding component identification. For example, sensors / transducers have been used and proposed in a large number of forms to collect data regarding environmental conditions, patient-related information, component identification, treatment implementation conditions, etc. In fact, many RT devices are equipped with one or more sensors such as flow sensors, pressure sensors, humidity sensors, temperature sensors, etc. Signals generated by such sensors can be analyzed to generate treatment-related data such as identification information for specific components such as the patient interface within a respiratory therapy system.

[0020] However, the fact that sensors / transducers typically require a series of additional components can prevent their adoption in many forms. For example, data collected by a sensor / transducer needs to be transmitted, e.g., from the sensor to a memory and / or a processor, for storage and / or analysis. This, along with the above-mentioned sensors, may further increase the costs for medical device manufacturers involved in design, testing, and / or manufacturing, and / or increase the costs and complexities for patients.

[0021] In addition, incorporating expensive electrical and / or mechanical functions into frequently replaced components, such as patient interfaces, is disadvantageous for providing the most cost-effective treatments and may also become environmentally unsustainable due to increased waste.

[0022] Furthermore, many of the measures proposed in relation to sensors and / or transducers are limited in that they often further increase the complexity and cost of implementation when sensors are proposed to be installed in locations remote from where the data is stored and / or analyzed. For example, when a patient interface includes a sensor, an electrical connection to an RT device is required, which may further increase the complexity and / or cost of implementation.

[0023] Also, designers of RT devices are often faced with numerous options and tend to come up with different solutions compared to competing devices from other companies or devices from the same manufacturer but with different manufacturing times. As a result, the provided related electrical connectors may be connectable to only a specific RT device, which may have the unintended effect of creating incompatibilities that can be disadvantageous to a particular consumer segment and / or reducing the consumer's options. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0024] BRIEF DESCRIPTION OF THE TECHNOLOGY The present technology relates to the provision of medical devices for use in the diagnosis, amelioration, treatment, or prevention of respiratory diseases, and these medical devices have one or more of improved comfort, cost, effectiveness, ease of use, patient engagement, and manufacturability.

Means for Solving the Problems

[0025] A first aspect of the present technology relates to an apparatus for use in the diagnosis, amelioration, treatment, or prevention of respiratory diseases.

[0026] Another aspect of the present technology relates to a method for use in the diagnosis, amelioration, treatment, or prevention of respiratory disorders.

[0027] One aspect of the present technology relates to an improved respiratory therapy device configured to identify components of a respiratory therapy system by acoustic means. In particular, the disclosed device comprises a structure and process configured to analyze acoustic reflections from system components to identify those components more accurately from their "acoustic signature" than heretofore. This improvement is achieved at least in part by implementing one or more structures that reduce the back reflection of sound from the device end of the air circuit, which can, for example, improve the discriminability of the acoustic signatures of different patient interface types. This improvement can also be achieved at least in part by signal processing that "flattens" the spectrum of an acoustic signal, such as a logarithmic spectrum, before converting it to an acoustic signature.

[0028] Some embodiments of the present technology can include a device that generates respiratory therapy. The device can include a pressure generator configured to generate pressurized air that is supplied from an outlet along an air circuit to a patient interface. The device can include a sensor configured to generate a sound signal representative of the sound of the pressure generator within the air circuit. The device can include a damping structure configured to reduce reflections of sound from the pressure generator along the air circuit. The device can include a controller. The controller can be configured to process the sound signal to identify the patient interface and / or the air circuit.

[0029] In some implementations, the damping structure can be formed by a through-pass damping duct configured to vary the acoustic impedance between the air circuit and the cavity of the housing of the pressure generator. The damping structure can define a cross-section of a passage through the through-pass damping duct or be defined by the cross-section of the passage, and the cross-section is configured to expand along the path of the passage due to the shape of the inner surface of the through-pass damping duct. The cross-section gradually expands as it moves away from the patient interface end of the air circuit. The device can include a waveguide formed at least by the outlet and the air circuit, the damping structure can be disposed between the sensor and the outlet along the waveguide, and the sensor can be disposed between the damping structure and the air circuit along the waveguide. The damping structure can be formed by a horn. The horn can have a conical shape.

[0030] Some implementations of the present technology include a method of identifying components of an air path coupled to a respiratory therapy device in a processor associated with the respiratory therapy device. The method can include processing a sound signal representative of sound within the air path to obtain a cepstrum. The processing can include flattening a spectrum of the sound signal. The processing can include separating an acoustic signature from the cepstrum. The processing can include comparing the acoustic signature to a set of predetermined acoustic signatures corresponding to respective components. The processing can include identifying a component based on a comparison of the acoustic signature and the set.

[0031] In some implementations, flattening can include removing a low-pass filtered sound signal from a logarithmic spectrum of the sound signal. Removing can include subtraction. The method can further include repeating the processing and separation at least once to generate a plurality of acoustic signatures. The method can further include combining the plurality of acoustic signatures into a composite acoustic signature. Comparing can be by comparing the composite acoustic signature to the set of predetermined acoustic signatures. Combining can include aligning one or more of the plurality of acoustic signatures with the composite acoustic signature. Combining can include averaging the plurality of acoustic signatures. The component can be a patient interface, and repeating can be synchronized with a respiratory cycle of a patient wearing the patient interface. Combining can be robust to slight variations in delay between the plurality of acoustic signatures. The method can include adjusting control parameters for operating a pressure generator of the respiratory therapy device based on the identification.

[0032] Some embodiments of the present technology can include a device that generates respiratory therapy. The device can include a pressure generator configured to generate pressurized air that is supplied from an outlet along an air circuit to a patient interface. The device can include a sensor configured to generate a sound signal representative of the sound of the pressure generator within the air circuit. The device can include a controller. The controller can be configured to process the sound signal to obtain a cepstrum. This processing can include flattening the spectrum of the sound signal. The controller can be configured to separate an acoustic signature from the cepstrum. The controller can be configured to compare the acoustic signature to a set of predetermined acoustic signatures corresponding to respective components. The controller can be configured to identify the patient interface and / or the air circuit based on the comparison of the acoustic signature to the set.

[0033] In some implementations, the device can include a damping structure configured to reduce reflections of sound from the pressure generator along the air circuit. The damping structure can be formed by a pass-through damping duct configured to vary the acoustic impedance between the air circuit and the cavity of the pressure generator housing. The damping structure can be formed by a horn. The horn can have a conical shape. The controller can be further configured to adjust control parameters for operating the pressure generator based on the identified patient interface and / or air circuit.

[0034] Some implementations of the present technology may include a method for identifying components of an air path connected to a respiratory therapy device in a processor associated with the respiratory therapy device. The method can include processing a sound signal representative of sound within the air path to obtain a cepstrum. The method can include separating an acoustic signature from the cepstrum. The method can include repeating the processing and separation at least once to generate a plurality of acoustic signatures. The method can include combining the plurality of acoustic signatures into a composite acoustic signature. The method can include comparing the composite acoustic signature to a set of predetermined acoustic signatures corresponding to respective components. The method can include identifying a component based on the comparison of the acoustic signature to the set.

[0035] In some implementations, the combining can include aligning one or more of the plurality of acoustic signatures with the composite acoustic signature. The combining can include averaging the plurality of acoustic signatures. The component can be a patient interface. The repeating can be synchronized with a respiratory cycle of a patient wearing the patient interface. The combining can be robust to variations in delay between the plurality of acoustic signatures. The processing can include flattening a spectrum of the sound signal. The flattening can include subtracting a low-pass filtered logarithmic spectrum from a logarithmic spectrum of the sound signal. The method can include adjusting control parameters for operating a pressure generator of the respiratory therapy device based on the identification.

[0036] Some implementations of the present technology may include a computer-readable medium having computer-readable instructions encoded thereon that, when executed by a processor of a controller of a respiratory therapy device, cause the processor to execute any one or more of the methods (s) or aspects described herein.

[0037] Some embodiments of the present technology may include a device for generating respiratory therapy. The device can include a pressure generator configured to generate pressurized air that is supplied from an outlet along an air circuit to a patient interface. The device can include a sensor configured to generate a sound signal representative of the sound of the pressure generator within the air circuit. The device can include a controller. The controller can be configured to process the sound signal to obtain a cepstrum. The controller can be configured to separate an acoustic signature from the cepstrum. The controller can be configured to repeat the processing and separation at least once to generate a plurality of acoustic signatures. The controller can be configured to concatenate the plurality of acoustic signatures into a composite acoustic signature. The controller can be configured to compare the composite acoustic signature to a set of predetermined acoustic signatures corresponding to respective components. The controller can be configured to identify the patient interface and / or the air circuit based on the comparison of the acoustic signature to the set.

[0038] In some implementations, the device can include an attenuation structure configured to reduce the reflection of sound from the pressure generator along the air circuit. This attenuation structure can be formed by a pass-through attenuation duct configured to vary the acoustic impedance between the air circuit and the cavity of the pressure generator housing. This attenuation structure can be formed by a horn. The horn can have a conical shape. To combine the plurality of acoustic signatures, the controller can be configured to align one or more of the plurality of acoustic signatures with the composite acoustic signature. To combine the plurality of acoustic signatures, the controller can be configured to average the plurality of acoustic signatures. The controller can be further configured to adjust control parameters for operating the pressure generator based on the identified patient interface and / or air circuit.

[0039] The methods, systems, devices, and apparatuses described herein enable improvement of functions in a processor (e.g., functions of a processor of a special-purpose computer, a respiratory monitor, and / or a respiratory therapy device). Further, the described methods, systems, devices, and apparatuses enable improvement in the technical field of automatic management, monitoring, and / or treatment of respiratory conditions (e.g., sleep disordered breathing).

[0040] Of course, some of the above aspects can form sub-aspects of the present technology. Also, various ones of the sub-aspects and / or aspects can be combined in various ways to form further aspects or sub-aspects of the present technology.

[0041] Other features of the present technology will become apparent in view of the information contained in the following detailed description, summary, drawings, and claims.

Brief Description of the Drawings

[0042] 4 Brief Description of the Drawings The present technology is shown for purposes of non-limiting illustration in the accompanying drawings. In the drawings, like reference numerals include the following like elements.

[0043] 4.1 Treatment System

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Best Mode for Carrying Out the Invention

[0044] 5 Detailed Description of Embodiments of the Technology Before further describing the present technology in detail, it should be understood that the present technology is not limited to the specific embodiments that may be described herein. It should also be understood that the terms used in the present disclosure are for the purpose of describing the specific embodiments described herein and are not limiting.

[0045] The following description is provided in relation to various embodiments that may share one or more common characteristics and / or features. It should be understood that one or more features of any one embodiment may be combined with one or more features of another embodiment or other embodiments. Additionally, any single feature or combination of features in any of these embodiments can constitute a further embodiment.

[0046] 5.1 Treatment Method In one form, the present technology includes a method for treating a respiratory disease. The method includes the step of applying positive pressure to the entrance of the airway of patient 1000.

[0047] 5.2 Treatment System In one form, the present technology includes a system for treating a respiratory disease. The respiratory therapy (RT) system may include an RPT device 4000 for delivering a positive pressure air supply to patient 1000 via a humidifier 5000, an air circuit 4170, and a patient interface 3000.

[0048] 5.3 Patient Interface An exemplary non-invasive patient interface 3000 is also shown in FIG. 3 and includes the following functional modalities. That is, a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilization structure 3300, a ventilation section 3400, one form of connection port 3600 for connection to the air circuit 4170, and a forehead support 3700. In some forms, the functional modalities can be provided by one or more physical components. In some forms, one physical component can provide one or more functional modalities. In use, the seal-forming structure 3100 is arranged to surround the inlet of the patient's airway so as to facilitate the supply of air at positive pressure to the airway.

[0049] A patient interface 3000 according to one form of the present technology is constructed and arranged to provide an air supply at positive pressure relative to the surroundings, for example, at least 4 cmH2O, or at least 10 cmH2O, or at least 20 cmH2O, or at least 25 cmH2O.

[0050] 5.3.1 Seal-forming structure In one form of the present technology, the seal-forming structure 3100 can provide a target seal-forming surface area and further provide a cushioning function. The target seal-forming area is the area in the seal-forming structure 3100 where sealing can occur. The area where sealing actually occurs (i.e., the actual sealing surface) can vary daily by the patient in a given treatment session depending on a range of factors (e.g., the placement position of the patient interface on the face, the tension in the positioning and stabilization structure, and the shape of the patient's face).

[0051] 5.3.2 Plenum chamber The plenum chamber 3200 has a perimeter of a shape that is complementary to the surface profile of an average person's face in the region where a seal is formed during use. During use, the peripheral edge of the plenum chamber 3200 is positioned close to the adjacent surface of the face. The actual contact with the face is provided by the seal forming structure 3100. The seal forming structure 3100 can extend around the entire edge of the plenum chamber 3200 during use. In some forms, the plenum chamber 3200 and the seal forming structure 3100 are formed from a single homogeneous piece of material. The acoustic generator 8500 can be formed as part of the plenum chamber 3200 or through the shell of the plenum chamber 3200.

[0052] 5.3.3 Positioning and Stabilization Structure The seal forming structure 3100 of the patient interface 3000 of the present technology can be held in a sealed position by the positioning and stabilization structure 3300 during use.

[0053] 5.3.4 Ventilation Port In one form, the patient interface 3000 includes a ventilation port 3400 configured and arranged to allow the extrusion of exhaled gas (e.g., carbon dioxide).

[0054] In certain forms, the ventilation port 3400 is configured to allow a continuous flow of ventilation from the inside of the plenum chamber 3200 to the atmosphere when the pressure in the plenum chamber is positive relative to the atmosphere. The ventilation port 3400 is configured such that, while maintaining the therapeutic pressure within the plenum chamber during use, the magnitude of the ventilation flow rate is large enough to reduce the rebreathing of exhaled CO2 by the patient. One form of the ventilation port 3400 according to the present technology includes a plurality of holes (e.g., from about 20 to about 80 holes, or from about 40 to about 60 holes, or from about 45 to about 55 holes).

[0055] The ventilation port 3400 can be disposed within the plenum chamber 3200. Alternatively, the ventilation port 3400 is disposed within a disconnect structure (e.g., a swivel).

[0056] 5.3.5 Connection Port The connection port 3600 enables connection to the air circuit 4170 and may optionally include an integrated acoustic generator 8500.

[0057] 5.4 RPT Device A respiratory pressure therapy (RPT) device 4000 according to one aspect of the present technology is shown in the exploded view of FIG. 4A and includes mechanical, pneumatic, and / or electrical components and is configured to execute one or more algorithms 4300. The RPT device 4000 can be configured to generate an air flow to be delivered to a patient's airway for treatment of one or more of the respiratory conditions described anywhere in this document, for example.

[0058] In one form, the RPT device 4000 is constructed and arranged to be able to deliver an air flow in the range of -20 L / min to +150 L / min while maintaining a positive pressure of at least 4 cmH2O or at least 10 cmH2O or at least 20 cmH2O or at least 25 cmH2O.

[0059] The RPT device can have an external housing 4010. The external housing 4010 is formed by two parts, an upper part 4012 and a lower part 4014. Further, the external housing 4010 can include one or more panels 4015. The RPT device 4000 includes a chassis 4016 that supports one or more internal components of the RPT device 4000. The RPT device 4000 can include a handle 4018.

[0060] The air of the RPT device 4000 Pressure channelThe circuit can include one or more air circuit items and a muffler 4120 (e.g., an inlet air filter 4112, an inlet muffler 4122, a pressure generator 4140 (e.g., a blower 4142) capable of supplying air under positive pressure, an outlet muffler 4124, and one or more transducers 4270 (e.g., a pressure sensor and a flow sensor)).

[0061] One or more of the air circuit items can be arranged within a removable integrated structure called a pneumatic block 4020. The pneumatic block 4020 can be arranged within an external housing 4010. In one form, the pneumatic block 4020 is supported by a chassis 4016 or formed as part of the chassis 4016.

[0062] The RPT device 4000 can have a power supply 4210, one or more input devices 4220, a central controller 4230, a treatment device controller 4240, a pressure generator 4140, one or more protection circuits 4250, a memory 4260, a transducer 4270, a data communication interface 4280, and one or more output devices 4290. The electrical components 4200 can be mounted on a single printed circuit board assembly (PCBA) 4202. In an alternative form, the RPT device 4000 can include more than one PCBA 4202.

[0063] 5.4.1 RPT Device Mechanical and Pneumatic Components The RPT device can include one or more of the following components in an integrated unit. In an alternative form, one or more of the following components can be arranged as separate units.

[0064] 5.4.1.1 Pressure Generator In one embodiment of the present technology, the pressure generator 4140 for generating a downstream air flow such as a flow or supplying air in positive pressure is a controllable blower 4142. The blower can deliver the air supply at a speed of, for example, up to about 120 liters per minute, at a positive pressure in the range of about 4 cmH2O to about 20 cmH2O, or in other embodiments up to about 30 cmH2O. The blower is described in any one of the following patents or patent applications, which are U.S. Patent No. 7,866,944, U.S. Patent No. 8,638,014, U.S. Patent No. 8,636,479, and PCT Patent Application Publication WO2013 / 020167. The entire above-mentioned documents are hereby incorporated by reference and made part of this specification.

[0065] The pressure generator 4140 is under the control of the treatment device controller 4240.

[0066] In other embodiments, the pressure generator 4140 can be a piston-driven pump, a pressure regulator connected to a high-pressure source (e.g., a pressurized air reservoir), or a bellows.

[0067] 5.4.1.2 Memory According to one embodiment of the present technology, the RPT device 4000 includes a memory 4260 (e.g., a non-volatile memory). In some embodiments, the memory 4260 can include a battery-powered static RAM. In some embodiments, the memory 4260 can include a volatile RAM.

[0068] The memory 4260 can be disposed on the PCBA 4202. The memory 4260 can be in the form of an EEPROM or a NAND flash.

[0069] Additionally or alternatively, the RPT device 4000 includes a removable memory 4260 (e.g., a memory card manufactured according to the Secure Digital (SD) standard).

[0070] In one form of the present technology, the memory 4260 functions as a non-transitory computer-readable storage medium. On this storage medium, computer program instructions or processor control instructions (e.g., one or more algorithms 4300) that represent one or more of the methods described herein are stored.

[0071] 5.4.1.3 Data Communication System In one form of the present technology, a data communication interface 4280 is provided and connected to the central controller 4230. The data communication interface 4280 can be connectable to a remote external communication network 4282 and / or a local external communication network 4284. The remote external communication network 4282 can be connectable to a remote external device 4286. The local external communication network 4284 can be connectable to a local external device 4288.

[0072] In one form, the data communication interface 4280 is part of the central controller 4230. In another form, the data communication interface 4280 is separate from the central controller 4230 and can include an integrated circuit or a processor.

[0073] In one form, the remote external communication network 4282 is the Internet. The data communication interface 4280 can use wired communication (e.g., via Ethernet or optical fiber) or a wireless protocol (e.g., CDMA, GSM, LTE) to connect to the Internet.

[0074] In one form, the local external communication network 4284 uses one or more communication standards (e.g., Bluetooth (registered trademark) or consumer infrared protocol).

[0075] In one form, the remote external device 4286 is one or more computers (e.g., a cluster of networked computers). In one form, the remote external device 4286 can be a virtual computer rather than a physical computer. In either case, such a remote external device 4286 can be accessible by appropriately authorized personnel (e.g., clinicians).

[0076] The local external device 4288 can be a personal computer, a mobile computing device such as a smartphone or a tablet device, or a remote control.

[0077] 5.4.2 RPT Device Algorithm As described above, in some forms of the present technology, the central control device 4230 can be configured to implement one or more algorithms 4300 represented as a computer program stored in a non-transitory computer-readable storage medium (e.g., the memory 4260). This algorithm 4300 is typically grouped into groups called modules.

[0078] 5.5 Humidifier 5.5.1 Overview of the Humidifier In one form of the present technology, the RT system includes a humidifier 5000 for changing the absolute humidity of the air to be delivered to the patient compared to the absolute humidity of the ambient air, between the RPT device 4000 and the air circuit 4170 (shown in FIG. 4A). Typically, the humidifier 5000 is used to increase the absolute humidity (relative to the ambient air) and the temperature of the air flow before it is delivered to the patient airway.

[0079] The humidifier 5000 can include (as shown, for example, in FIG. 5A), a humidifier reservoir 5110, a humidifier inlet 5002 for receiving an air flow, and a humidifier outlet 5004 for delivering a humidified air flow. In some forms, as shown in FIGS. 5A and 5B, the inlet and outlet of the humidifier reservoir 5110 can be the humidifier inlet 5002 and the humidifier outlet 5004, respectively. The humidifier 5000 can further include a humidifier base 5006. The humidifier base 5006 can be adapted to receive the humidifier reservoir 5110 and can include a heating element 5240.

[0080] 5.5.2 Components of the Humidifier 5.5.2.1 Water Reservoir According to one arrangement, the humidifier 5000 can include a water reservoir 5110 configured to contain or hold a certain amount of liquid (e.g., water) to be evaporated for humidifying the air flow. The water reservoir 5110 can be configured to contain a predetermined maximum amount of water to provide adequate humidification over at least a respiratory therapy session (e.g., an overnight sleep). Typically, the reservoir 5110 is configured to contain several hundred milliliters of water (e.g., 300 milliliters (ml), 325 ml, 350 ml, or 400 ml). In other forms, the humidifier 5000 can be configured to receive a water supply from an external water source (e.g., a building's water supply system).

[0081] According to one aspect, the water reservoir 5110 is configured to humidify the air flow from the RPT device 4000 as the air flow passes through the RPT device 4000. In one form, the water reservoir 5110 can be configured to facilitate movement of the air flow through a serpentine path in the reservoir 5110 while the air flow is in contact with a certain amount of water in the reservoir 5110.

[0082] According to one form, the reservoir 5110 is removable from the humidifier 5000 horizontally, as shown, for example, in FIGS. 5A and 5B.

[0083] The reservoir 5110 can also be configured to suppress liquid release from the reservoir 5110 when, for example, the reservoir 5110 is displaced and / or rotated from its normal operating direction (e.g., through any aperture and / or between its sub-components). Since the air flow to be humidified by the humidifier 5000 is often pressurized, the reservoir 5110 can also be configured to prevent air pressure loss through leakage and / or flow impedance.

[0084] 5.5.2.2 Conductive Portion In one arrangement, the reservoir 5110 includes a conductive portion 5120 configured to enable efficient heat transfer from the heating element 5240 to a certain amount of liquid in the reservoir 5110. In one form, the conductive portion 5120 can be arranged as a plate, although other shapes may also be suitable. All or part of the conductive portion 5120 can be constructed of a thermally conductive material such as aluminum (e.g., having a thickness of about 2 mm (e.g., 1 mm, 1.5 mm, 2.5 mm, or 3 mm)), another thermally conductive metal, or some plastic. In some cases, suitable thermal conductivity can be achieved with a lower conductivity material of appropriate geometry.

[0085] 5.5.2.3 Humidifier Reservoir Dock In one form, the humidifier 5000 can include a humidifier reservoir dock 5130 configured to receive the humidifier reservoir 5110 (as shown in FIG. 5B). In some arrangements, the humidifier reservoir dock 5130 can include a locking function (e.g., a locking lever 5135 configured to hold the reservoir 5110 within the humidifier reservoir dock 5130).

[0086] 5.5.2.4 Water Level Indicator The humidifier reservoir 5110 can include a water level indicator 5150 as shown in FIGS. 5A - 5B. In some forms, the water level indicator 5150 can provide one or more indications about the amount of water in the humidifier reservoir 5110 to a user such as patient 1000 or a caregiver. These one or more indications provided by the water level indicator 5150 can include a maximum indication, an indication of a predetermined amount of water, or an indication of any portion thereof (e.g., 25%, 50%, or 75%, or amounts such as 200 ml, 300 ml, or 400 ml).

[0087] 5.5.2.5 Humidifier Transducer(s) The humidifier 5000 can include one or more humidifier transducers (sensors) 5210 instead of or in addition to the transducer 4270 described above. The humidifier transducer 5210 can include one or more of an air pressure sensor 5212, an air flow transducer 5214, a temperature sensor 5216, or a humidity sensor 5218. The humidifier transducer 5210 can generate one or more output signals. These output signals can communicate to a controller (e.g., central controller 4230 and / or humidifier controller 5250). In some forms, the humidifier transducer can be disposed outside of the humidifier 5000 (e.g., within the air circuit 4170) while communicating the output signal to the controller 5250.

[0088] 5.6 Air Circuit An air circuit 4170 according to one aspect of the present technology is a conduit or tube constructed and arranged such that during use a pressurized air flow moves between two components (e.g., the humidifier 5000 and the patient interface 3000).

[0089] Specifically, the air circuit 4170 can be in fluid communication with the outlet 5004 of the humidifier 5000 and the plenum chamber 3200 of the patient interface 3000.

[0090] 5.7 Transducer(s) The RT system may include one or more transducers (sensors) 4270 configured to measure one or more of any number of parameters related to the RT system, its patient, and / or its environment. The transducer can be configured to produce an output signal representing one or more parameters that the transducer is configured to measure.

[0091] This output signal can be one or more of any number of other signals known in the art, such as an electrical signal, a magnetic signal, a mechanical signal, a visual signal, an optical signal, an acoustic signal, etc.

[0092] The transducer can be integrated with other components of the RT system, and one exemplary arrangement is where the transducer is built into the RPT device. The transducer can be a substantially “stand-alone” component of the RT system, and an exemplary arrangement would be where the transducer is external to the RPT device.

[0093] The transducer can be configured to transmit its output signal to one or more components of the RT system, such as the RPT device, a local external device, or a remote external device. An external transducer can be placed, for example, on a patient interface or on an external computing device such as a smartphone. The external transducer can be placed, for example, on an air circuit or can form part of an air circuit (e.g., a patient interface).

[0094] One or more transducers 4270 can be constructed and arranged to generate a signal indicative of a property of air (e.g., flow rate, pressure, or temperature). The air can be the air flow from the RPT device to the patient, the air flow from the patient to the atmosphere, ambient air, or others. The signal can represent the nature of the air flow at a specific point, such as the air flow in the air pressure path between the RPT device and the patient. In one form of the present technology, one or more transducers 4270 can be located in the air pressure path of the RPT device, such as downstream of the humidifier 5000.

[0095] 5.7.1 Pressure Sensor According to one aspect of the present technology, one or more transducers 4270 include a pressure sensor located in fluid communication with the air pressure path. One example of a suitable pressure sensor is a transducer from the ASDX series manufactured by HONEYWELL. Another suitable pressure sensor is a transducer from the NPA series from GENERAL ELECTRIC. In one embodiment, the pressure sensor is located in the air circuit 4170 adjacent to the outlet 5004 of the humidifier 5000.

[0096] The pressure sensor (microphone) 4270 is configured to generate an acoustic signal representative of a change in pressure within the air circuit 4170. The acoustic signal from the microphone 4270 can be received by the central controller 4230 for acoustic processing and analysis, as configured by one or more of the algorithms 4300 described below. The microphone 4270 can be directly exposed to the air path to enhance its sensitivity to sound, or it can be encapsulated on the back side of a thin layer of flexible membrane material. This membrane can function to protect the microphone 4270 from heat and / or moisture.

[0097] 5.8 Acoustic Analysis According to one or more aspects of the present technology, acoustic analysis can be used for the purpose of determining one or more parameters related to a respiratory disease or a system for the treatment of a respiratory disease.

[0098] The acoustic analysis according to the aspects of the present technology can have one or more advantages over the prior art, such as reduction of treatment costs, provision of higher-quality treatment, improvement of the usability of treatment systems, reduction of waste, and provision of low-cost digital connection.

[0099] As will become apparent in the remainder of the context of this document, the terms "acoustic", "sound", and "noise" in this document are generally intended to include air vibrations regardless of whether they are audible. Therefore, the terms "acoustic", "sound", and "noise" in this document are intended to include air vibrations in the ultrasonic or subsonic regions unless otherwise stated.

[0100] Some implementations of the disclosed acoustic analysis technology may perform cepstrum analysis. The cepstrum can be regarded as, for example, the inverse Fourier transform of the logarithmic spectrum of the forward Fourier transform of the decibel spectrum. By this operation, the impulse response function (IRF) and the convolution of the sound source can be substantially converted into an addition operation, whereby the sound source can then be easily considered or the sound source can be removed so as to separate the IRF data for analysis. The technology of cepstrum analysis is described in detail in the scientific literature (title: "The Cepstrum: A Guide to Processing" (Childers et al., Proceedings of the IEEE, Vol. 65, No. 10, Oct 1977)) and Randall RB, Frequency Analysis, Copenhagen: Bruel & Kjaer, p. 344 (1977, revised ed. 1987). The application of cepstrum analysis to the characteristics of respiratory treatment system components is described in PCT Publication No. WO2010 / 091462 (title: "Acoustic Detection for Respiratory Treatment Apparatus"), and the entire document is incorporated herein by reference.

[0101] The cepstrum analysis can be understood from the nature of convolution. The convolution of f and g can be denoted as f*g. This operation can be the integral after the product of the two functions (f and g) is inverted and shifted. Therefore, it is a kind of integral transform as follows. [Mathematics]

[0102] Although the symbol t is used in the above formula, it is not necessary to represent the time domain. However, in that context, the convolution formula can be described as the weighted average of the function f(τ) at the instant t, and the weighting is given by g(-τ) simply shifted by the amount t. When t changes, this weighting function emphasizes different parts of the input function.

[0103] A mathematical model that can relate the input to the output of a time-invariant linear acoustic system, such as the pneumatic path of a respiratory therapy system, can be based on convolution. The sound signal generated by the microphone 4270 in the air circuit 4170 is regarded as the input sound signal "convolved" with the system impulse response function (IRF) as a function of time (t). y(t)=s1(t)*h1(t) (2)

[0104] In the formula, y(t) is the output sound signal generated by the microphone 4270, s1(t) is the input sound signal such as the sound generated in or by the pressure generator 4140 of the respiratory therapy device 4000, and h1(t) is the system IRF from the sound source to the microphone 4270. The system IRF h1(t) can be considered as the system response to a unit impulse input.

[0105] When equation (2) is transformed into the frequency domain by taking the Fourier transform (e.g., discrete Fourier transform ("DFT") or fast Fourier transform ("FFT")) of the sound signal y(t) and considering the convolution theorem, the following equation is obtained. Y(f) = S1(f)H1(f) (3)

[0106] Where Y(f) is the Fourier transform (spectrum) of y(t), S1(f) is the Fourier transform of s1(t), and H1(f) is the Fourier transform of h1(t). In other words, convolution in the time domain becomes multiplication in the frequency domain.

[0107] A logarithmic operation can be applied to equation (3) so that multiplication is converted to addition. Log{Y(f)} = Log{S1(f)} + Log{H1(f)} (4)

[0108] Equation (4) is transformed back to the time domain by the inverse Fourier transform (IFT) (e.g., inverse DFT or inverse FFT), resulting in a complex-valued "cepstrum" (the inverse Fourier transform of the logarithm of the spectrum Y(f)). [Number]

[0109] The τ on the abscissa is a real-valued variable called quefrency, and the unit of measurement is seconds. Therefore, the effect that is convolution in the time domain becomes additive in the logarithm of the spectrum and remains the same in the cepstrum and quefrency domains. In particular, the output cepstrum [Number] is the cepstrum of the input signal s1(t) [Number] and the cepstrum of the system IRF h1(t) [Number] consisting of two additive components.

[0110] By examining data values in the cepstrum domain, such as examining cepstrum analysis data, information regarding the RT system can be provided. For example, by comparing the cepstrum data of the system with a previous baseline or a known baseline of the cepstrum data of the system, differences or similarities of the system that can be used to implement automatic control for various functions or purposes can be recognized using comparisons such as differences.

[0111] 5.8.1 Identification of Components As described above, a respiratory therapy system can typically include an RPT device, a humidifier, an air delivery conduit, and a patient interface. A variety of different forms of patient interfaces can be used with a given RPT device (e.g., nasal pillows, nasal prongs, nasal masks, nasal and oral (naso-oral) masks, or full face masks). Further, different forms of air delivery conduits can be used. Even in a general form, among various models of the form of the patient interface (e.g., various nasal masks), there can be differences in design specifications such as size and / or shape. For improving the control of treatment delivery to the patient interface, measurement or estimation of treatment parameters (e.g., pressure and ventilation flow in the patient interface) can be advantageous. In a system using estimation of treatment pressure, by knowing the type of component the patient is using, the estimation accuracy of the treatment pressure can be increased, and thus the effect of the treatment can be enhanced. To grasp this, in some RPT devices, a menu system is included that enables the patient to select the type of system component (e.g., the patient interface being used) (e.g., brand, form, model, etc.). When the patient inputs the type of component, the RPT device controller can select appropriate operating parameters of the RPT device that optimally cooperate with the selected component.

[0112] The present technology can provide improvements to known devices for facilitating cooperation between an RPT device and the peripheral components of an RT system based on acoustic analysis to identify the components of the RT system. As used herein, "identification" of a component means identifying the type of that component so as to distinguish it from other different (e.g., pneumatically different) types of components that can be used in the RT system. Thereafter, such identification can permit access to data associated with the identification, such as pneumatic characteristics applicable in its pneumatic control (e.g., treatment control) by the controller of the RT device. Although there are patient interfaces that are not normally referred to as "masks", in the following content, for the sake of simplicity, "mask" is used synonymously with "patient interface".

[0113] The first embodiment of the present technology comprises a device, apparatus, and / or method for identifying components (s) within a respiratory treatment system. These components can be a mask and a conduit. This embodiment can identify the length of the conduit in use in addition to the mask connected to the conduit. This technology can identify the mask and the conduit regardless of whether the patient is wearing the mask at the time of identification.

[0114] The present technology can perform an analysis of the sound signal generated by the microphone 4270 arranged as described above.

[0115] According to the analysis method included in the present technology, it is possible to separate the reflection of the acoustic mask from other system noises and responses (non-limiting examples include blower noise). As a result, it becomes possible to identify the differences between the acoustic reflections of different masks (which are often determined by the shape, configuration, and material of the mask), and it becomes possible to identify different masks, such as without requiring intervention by the user or patient.

[0116] An example of a method for identifying a mask is to sample the output sound signal y(t) generated by the microphone 4270 at a desired sampling rate, such as 20 kHz, which is above the Nyquist rate. Cepstrum

Number

[0117] Alternatively, using the same method, the length of the conduit can be determined by obtaining the delay between the sound received from the RPT device and the reflection from the mask. This delay can be proportional to the length of the conduit. In addition, changes in the pipe diameter can enlarge or reduce the amplitude of the reflected signal and are thus distinguishable. Such an evaluation is performed by comparing the current reflection data with the previous reflection data. The change in diameter can be regarded as the ratio of the change in amplitude from the reflected signal (i.e., the reflection data).

[0118] Figure 7 is a schematic diagram of an RT system 7000 according to one aspect of the present technology. In this exemplary embodiment shown in Figure 7, a conduit 7010 (of length L) effectively functions as an acoustic waveguide for sounds generated by an RPT device 7040, such as sound from a speaker, or alternatively, only the operating noise of a blower (e.g., a motor and / or an impeller). In this exemplary embodiment, the input signal is the sound emitted by the RPT device 7040 (i.e., without the sound from the speaker). This input signal (e.g., an impulse) enters a microphone 7050 positioned at one end of the conduit 7010, moves along the air path within the conduit 7010 to a mask 7020, reflects back along the conduit 7010 due to the characteristics of the air path (including the conduit and the mask), and enters the microphone 7050 again. Therefore, the system IRF (output signal created by the input impulse) includes an input signal component and a reflected component. The main characteristic of the RT system 7000 is the time it takes for sound to travel from one end of the air path to the opposite end. Since the microphone 7050 receives the input signal from the RPT device 7040 and then, after a while, receives the input signal filtered by the conduit 7010 and reflected and filtered by the mask 7020 (and potentially other systems 7030 attached to the mask, such as a human respiratory system when the mask 7020 is worn by a patient), this interval is manifested in the system IRF. This means that the component of the system IRF (reflected component) associated with the reflection from the mask end of the conduit 7010 arrives at the microphone 7050 after a relatively short delay compared to the component of the system IRF (input signal component) associated with the input signal that arrives at the microphone 7050. (In practice, this short delay can be ignored, and the zero time can be approximated when the microphone 7050 first responds to the input signal). This delay is equal to 2L / c, where L is the length of the conduit and c is the speed of sound within the conduit).

[0119] Another feature of system 7000 is that, because losses are likely to occur in the air path, if the length of the conduit is sufficient, the input signal component of the system IRF will attenuate to a negligible amount by the time the reflected component of the system IRF begins. When this is the case, the input signal component can be separated from the reflected component of the system IRF. As an example, FIG. 8 shows an example of such a system IRF from a treatment system example where the input signal can originate from the blower 4142 of the RPT device. Alternatively, this input signal can include sound emitted from a speaker at the device end of the air path (with or without the sound generated by the RPT device 7040). FIG. 8 shows how the reflected component 8020 of the system IRF appears with a delay equal to 2L / c from the input signal component 8010 of the system IRF.

[0120] The cepstrum of the system IRF associated with the aforementioned equations (2), (4), and (5)

Number

Number

Number

Number

[0121] This separation can be achieved when the input signal s1(t) is non-stationary random (e.g., impulse) or stationary random. That is, the cepstrum input signal component

Number

Number

[0122] Figure 9 depicts the real parts of various cepstrum examples obtained from measurements of a treatment system implemented using three different masks, such as the system of Figure 7, where the input signal is the sound generated by an RPT device blower. Each mask in this example was tested at two different blower operating speeds of 10 krpm and 15 krpm. These speeds were used in these examples, but in particular, this technique can be implemented at other blower speeds if the resulting sound is detectable by microphone 7050.

[0123] In Figure 9, in all six cepstrums, it can be clearly confirmed that the reflection component starts from around 12 milliseconds (12 ms) of cepstrum. In this example of the treatment system, a 2-meter catheter is used, and since the speed of sound is 343 m / s, this position is as expected (2L / c). The graph in Figure 9 shows the cepstrum from the mask in the order from top to bottom. - ResMed Ultra Mirage (registered trademark) tested at -10 krpm, - ResMed Ultra Mirage (registered trademark) tested at -15 krpm, - ResMed Mirage Quattro (registered trademark) tested at -10 krpm, - ResMed Mirage Quattro (registered trademark) tested at -15 krpm, - ResMed Swift II (registered trademark) tested at -10 krpm, and - ResMed Swift II (registered trademark) tested at -15 krpm.

[0124] By increasing the length of the catheter, the arrival delay of the reflection from the mask can also be significantly increased. Compared with Figure 9, this increase in delay conforms to the aforementioned calculation that generates an approximation of the catheter length.

[0125] According to this technology, data associated with the reflection component, such as the data depicted in the center in the cepstrum of Figure 9, can be compared with similar data obtained from a set of predetermined acoustic signatures such that the data is included in a previously identified set of mask reflection components, or the memory or database of mask reflection components. Such a set can include data from one or more of such previously identified mask reflection components.

[0126] For example, the reflection component of a mask during testing (the "mask signature") can be separated from the cepstrum of the output signal generated by a microphone. This mask signature can be compared to the previous mask signature of a known mask or the reflection component of a predetermined mask signature stored as a data template of the device for purposes such as verifying the identification of a known mask. One way to do this is to calculate the cross-correlation between the mask signature of the mask being tested and the mask signatures previously stored for all known masks or data templates. The cross-correlation with the highest peak is likely to correspond to the mask being tested, and the position of the peak should be proportional to the length of the conduit.

[0127] However, by increasing the number of correlation points, the accuracy of the identification step of the present technology can also be improved. Therefore, additional data points can be utilized. Optionally, a least-squares algorithm using test data and known data sets can be implemented in the identification of components. Further, in some embodiments, additional feature extraction and recognition techniques based on artificial intelligence / machine learning structures and strategies such as neural networks and support vector machines can be utilized. Also, other information sources can be included as inputs to such structures and strategies to increase the accuracy of component identification. Specific examples include patient characteristics, treatment data, historical information such as previously identified components, geographical location, and related market data such as the sales volume of various components.

[0128] One factor that complicates the identification of acoustic components is the acoustic "back-reflection" from the device side of the conduit 7010. These back-reflections occur at the device end of the conduit 7010 as a result of a change in the acoustic impedance between the conduit 7010 and the internal cavity of the RPT device / humidifier 7040 to which the conduit 7010 is connected, after the sound reflected from the mask 7020 returns along the conduit 7010. Such back-reflections can have a confounding effect on the acoustic signature of the mask. For example, when the dimensions of the component being identified are on a physical scale similar to the distance between the microphone 7050 and any discontinuity in the cross-section inside the RPT device / humidifier 7040, the reflections from the component can superimpose on the output signal as a response to the back-reflection.

[0129] Figure 10 depicts a graph showing this effect. Trace 1050 is an output cepstrum that includes a distinct peak 1060 in the cepstrum associated with the sound transmitted from the microphone to the component being identified and the sound reflected back from that component to the microphone. The cepstrum trace 1050 also includes a distinct trough 1070 in the cepstrum associated collectively with (a) the sound transmitted from the microphone to the component, (b) the reflection from the component down the conduit and back to the blower device end of the conduit, and (c) the back-reflection from the blower device end to the microphone.

[0130] In some cases, it may be possible to improve the identification accuracy of the component by characterizing the back-reflection and deconvolving from the reflected component. Alternatively, if the back-reflection can be reduced or minimized by design, the identification accuracy of the component may be improved. In the latter case, it becomes complicated because it is necessary to maintain an open passage from the blower end to the patient interface so that the treatment pressure can be supplied to the waveguide formed by the treatment conduit.

[0131] In such an implementation form 1105 shown in FIG. 11, the end of the conduit 1110 that is closest to the microphone 1150 and distal from the patient's respiratory tract 1130 includes a dampening structure 1160 configured to reduce back reflection. Since the structure of such a dampening structure can generally be open so as to have a passage for (therapeutic) air flow and sound, it can be regarded as a through-pass (acoustic) damping conduit. Such a through-pass damping conduit may be a transitional conduit passage having an inner surface that defines a cross-section of the passage through its structure, and the cross-section expands linearly, for example, along the acoustic or air flow path of the conduit passage depending on the shape of the inner surface. As shown, the structure 1160 can be arranged along the conduit between the microphone and the blower so that the microphone comes between the structure and the patient interface along the conduit. The example of the structure 1160 in FIG. 11 is shown as a horn extending into the internal cavity of the RPT device / humidifier 1140 whose cross-sectional or lateral dimension (e.g., diameter) gradually increases in a direction away from, for example, the identified component, from the device end of the conduit 1110 that can have the same diameter as the conduit 1110. In this regard, the cross-section of the structure 1160 expands from its inner surface shape as the cross-section moves away from the patient interface end of the patient circuit. Since the acoustic impedance of an acoustic waveguide is related to the internal lateral dimension (e.g., diameter) of the waveguide, the horn structure 1160, unlike an absorbent material, minimizes back reflection by gently changing the acoustic impedance between the conduit 1110 and the cavity of the RPT device / humidifier 1140. The horn structure 1160 may be conical as shown in FIGS. 11 and 11A, and the shape of the horn may be curved like the bell of a brass instrument as in the example of FIG. 11B. The effect of the structure 1160 is to enhance the distinguishability of the system components by reducing the back reflection component in the acoustic signature of the system components 1120.

[0132] The cepstrum can be calculated over a finite time window of the sampled output signal y(t). The longer the window, the cleaner separation can occur between the acoustic signature and the input signal components. However, since the acoustic characteristics of the air path can change over time due to factors such as pressure during the respiratory cycle, and / or flow rate during the respiratory cycle, and / or changes in humidity during the respiratory cycle, when evaluated by the patient during use, this window should not be made so long that a large change in the air path characteristics is expected midway. In one example, the duration of the window is 200 ms.

[0133] Performing the IFT of equation (5) to obtain the cepstrum

Number

Number

Number

Number

Number

[0134] Multiple output cepstra [Number] can be calculated over multiple windows, and the acoustic signatures extracted from each cepstrum can be combined into a single composite acoustic signature and then compared with previously measured acoustic signatures (e.g., template data). In some embodiments, this combination is the averaging of multiple acoustic signatures. Such a combination tends to reduce the effect of noise on the composite acoustic signature.

[0135] To minimize the variable effect of the breathing cycle on the acoustic characteristics of the air path, and thus the variability of the acoustic signature between windows, the timing of the windows can be aligned (synchronized) with specific points in the breathing cycle, such as the peak of the inspiratory flow or the pause at the end of exhalation. In a similar manner, the windows can be synchronized with a specific shaft rotation speed of the RT device to reduce or emphasize the effect of the rotating machine on the signature. In some embodiments, the acoustic analysis can include the diagnosis or prediction of the state of the machine, such as the failure of a bearing.

[0136] Even in such a "breathing-synchromized" embodiment, other sources of variability in the air path between the windows can affect the relative delays of each acoustic signature in the cephalic region. Depending on how the acoustic signatures are grouped, the composite acoustic signature can become unclear or blurred, affecting its discriminability.

[0137] Therefore, in some implementations, a combination method that is robust to small variations in the delay (relative shift along the cephalic axis) between multiple acoustic signatures can be selected. In such an embodiment, the newly calculated acoustic signatures are incorporated one by one into the composite acoustic signature, gradually building the composite acoustic signature from each newly calculated acoustic signature. To achieve this incorporation, each newly calculated acoustic signature can be compared with the composite acoustic signature to estimate the delay with respect to the composite acoustic signature. The estimated relative delay can be compensated by shifting the acoustic signature by the estimated delay amount before incorporating the newly calculated acoustic signature into the composite acoustic signature. In such an embodiment, the delay can be estimated by finding the position of a prominent feature of the acoustic signature, such as the largest negative peak. In an alternative implementation, the delay can be estimated by correlating the acoustic signature with the composite acoustic signature and identifying the peak of the correlation. The delay estimation and compensation of the acoustic signature can be referred to as alignment of the acoustic signature. In the case of combination by averaging, each shifted acoustic signature can be averaged with the combined signature.

[0138] Other combination techniques can create a composite acoustic signature that is robust to small variations in delay, such as a wavelet transform-based combination.

[0139] Figure 12 is a flowchart showing a method 1200 for identifying components of an air path of a respiratory therapy system according to one aspect of the present technology. Method 1200 may start at step 1210 of calculating an output cepstrum during the passage of a respiration-synchronized window as described above in relation to equation (5). Step 1210 optionally flattens the logarithmic spectrum Log{Y(f)} before calculating the output cepstrum as described above.

Number

Number

[0140] Subsequently, at step 1220, the reflection component (acoustic signature) is separated from the cepstrum calculated at step 1210. In the next step 1230, the acoustic signature is incorporated into the composite acoustic signature in a robust manner for a small shift in the cepstrum domain as described above. (In the first pass through this loop, step 1230 simply designates the acoustic signature as the composite acoustic signature).

[0141] Subsequently, step 1240 checks whether sufficient acoustic signatures have been incorporated to constitute the composite acoustic signature. If not ("N"), method 11000 proceeds to step 1260, waits for the next respiration-synchronized window, and then returns to step 1210 to calculate a new cepstrum. If so ("Y"), step 1250 identifies the current component by comparing the composite acoustic signature with a default signature dataset or a predetermined signature dataset, such as a signature dataset of previously measured acoustic signatures obtained from a system including known components. Next, method 1200 ends.

[0142] FIG. 13 depicts two graphs. The upper graph 1300 shows a set of unaligned acoustic signatures when the length of the tube varies between the windows. The lower graph 1350 shows the same set of acoustic signatures after alignment according to the above-described maximum negative peak embodiment. It can be confirmed that alignment results in a set of composite acoustic signatures that are more clearly defined than the set of unaligned acoustic signatures.

[0143] The signal processing analysis described in connection with FIG. 12 can be performed by a controller or processor, such as by using firmware, hardware, and / or software, as previously described. Such a controller can identify the mask and the conduit. This identification information or data related to the identity of the patient interface can then be relayed to a further controller, processor, system, or computer or used by the controller. This information can then be utilized when the respiratory therapy system performs respiratory therapy and when adjusting other settings for the purpose of treatment settings and control of the RPT device.

[0144] For example, the above technique can be implemented as part of a controller of a respiratory therapy system, such as a CPAP device. Such an implementation can help reduce the need for a user or clinician of the CPAP device to manually enter or adjust the settings of the device for use in combination with a particular mask. Thus, in some embodiments of the present technology, since such a system automatically sets the device with settings adjusted according to the automatically identified patient interface or mask configuration, a user can even replace the mask without performing the inputs and settings required for the CPAP device. In some cases, the identification information obtained by the above-described automated process can be used to prompt the user to simply enter confirmation of the identification information, thereby avoiding or reducing the need to scroll through a number of patient interface items on the user interface of the RT device for setup, thus simplifying the setup.

[0145] In addition, in some embodiments, information regarding the identity of a particular mask may be selectively transmitted to a manufacturer, physician, or clinician for use in assisting with patient troubleshooting. Such data can be transmitted, for example, by a wireless communication protocol such as Bluetooth® and / or Wi-Fi®.

[0146] In addition, in some embodiments, information regarding the identity of a particular mask can be used to trigger actions such as manually or automatically deploying personalized coaching or training content related to the particular mask, such as a tutorial regarding the implementation of mask adjustment. Such content can be communicated to the user via the screen of the treatment device or the corresponding mobile device application, or other communication means such as email or SMS messages.

[0147] Alternatively, in some embodiments of the present technology, a controller can be configured to detect whether a patient is currently wearing a mask, for example, by comparing test cepstrum data with template cepstrum data recorded during the patient's use, based on the nature of acoustic reflections. Similarly, the present technology can be implemented for the purpose of determining the presence or absence of technical problems with the mask, including leaks and / or twists of the system. This can also be detected by comparing current test cepstrum data with cepstrum data recorded when the mask was operating well and properly worn on the patient's face (e.g., without leaks).

[0148] In some embodiments, during the identification of components, a blower speed greater than the above speed can be implemented. For example, some ducts can use materials having properties that can reduce noise. In such a system, the acoustic losses of the system can vary. If the losses detected by the measured signal increase (e.g., a decrease in amplitude), the decibel of the sound source or noise source can be increased to overcome the influence of the sound loss. This can be achieved by increasing the speed of the blower during the test measurement process. In addition, other elements included in the air path can increase the acoustic losses. These elements can include, for example, humidifiers, noise baffles, valves, and the like. Again, the losses caused by these components can also be overcome by increasing the level or amplitude of the noise source. Typically, the appropriate volume level of the input signal can be above about 20 dBa.

[0149] The frequency range of the microphone 4270 can be selected according to the geometric resolution required for the identification of components. To resolve information about small dimensions, typically high-frequency components in the generated sound signal are required. A typical air circuit for respiratory therapy exhibits tube resonances with a fundamental frequency of less than 100 Hz, but harmonics above 10 kHz, which are integer multiples of the fundamental frequency, appear in the spectrum. The frequency range of the microphone 4270 can be selected such that the period associated with the harmonic spacing is large enough to sense sufficient resonant harmonics present in the inverse Fourier transform of the logarithmic spectrum. Thus, in one embodiment, the microphone 4270 has a frequency upper limit of at least 10 kHz.

[0150] As described above, some embodiments can generate sound impulses or white noise using a sound source such as a speaker. This can be particularly effective in a respiratory therapy system equipped with a very quiet blower that does not generate noise. For example, when using a ResMed® RPT device generally at a speed of less than 6 krpm, the blower is very quiet. In this situation, even using only the sound of the blower as the sound source to create an input signal may be insufficient for identifying some components. This problem can be overcome by including an additional sound source in the air path. This can be activated during the measurement period, such as when the mask is first attached to the conduit. The additional sound source can be a speaker, but other sound emitters can also be used. For example, a simple acoustic generator such as a reed that is selectively activated and deactivated (e.g., mechanically applied to and removed from the air path of the system) can be configured to vibrate in response to the air flow from the RPT device. This can serve to selectively generate sound impulses. Alternatively, the valve of an operating RPT device can be an additional sound source.

[0151] In addition, a sound source such as a speaker can be used for the purpose of filling in the gaps in the sound spectrum generated by the blower. For example, a speaker can be used to generate a signal designed to have a specific spectrum and add the sound of the blower and the sound of the speaker to generate a white spectrum. This can not only improve the detection accuracy of the system but also improve the perceived sound quality experienced by the user of the therapy device.

[0152] In some embodiments, the mask can be designed to have unique acoustic response characteristics. For example, a unique sound resonator or unique characteristic dimensions can be designed within the mask or conduit so that the acoustic reflection data of each mask can be easily distinguished.

[0153] In some embodiments, autocorrelation (i.e., the inverse Fourier transform of the power spectrum) can be performed instead of cepstrum analysis.

[0154] In a further embodiment of the present technology, in addition to identifying the type, acoustic reflections can be analyzed for the purpose of identifying specific mask characteristics. For example, system response data can be utilized for the purpose of identifying the characteristics of a mask or conduit. These characteristics include diameter, constituent material, cavity volume, overall configuration of the mask and conduit, and the like.

[0155] 5.9 Glossary For the purposes of disclosing the present technology, in certain forms of the present technology, one or more of the following definitions apply. In other forms of the present technology, other definitions may apply.

[0156] 5.9.1 General Air: In certain forms of the present technology, air means the atmosphere, and in other forms of the present technology, air may mean a combination of other breathable gases (e.g., an oxygen-rich atmosphere).

[0157] Atmosphere: In certain forms of the present technology, the term "atmosphere" should be taken to mean (i) outside of the respiratory therapy system or the patient, and (ii) that which directly surrounds the respiratory therapy system or the patient.

[0158] For example, the ambient humidity for a humidifier can be the humidity of the air that directly surrounds the humidifier (e.g., the humidity inside the room where the patient is sleeping). Such ambient humidity may differ from the humidity outside the room where the patient is sleeping.

[0159] Automatic Positive Airway Pressure (APAP) therapy: A CPAP therapy that can automatically adjust the therapy pressure between a minimum limit and a maximum limit, for example, during breathing, depending on the presence or absence of notification of the onset of SDB.

[0160] Continuous Positive Airway Pressure (CPAP) therapy: A respiratory pressure therapy in which the treatment pressure is approximately constant throughout the patient's respiratory cycle. In some forms, the pressure at the airway inlet rises slightly during exhalation and drops slightly during inhalation. In some forms, the pressure varies between different respiratory cycles of the patient (e.g., increased in response to detection of signs of partial upper airway obstruction and reduced in the absence of notification of partial upper airway obstruction).

[0161] Flow rate: The instantaneous amount (or mass) of air delivered per unit time. Flow rate can refer to the instantaneous amount. In some cases, when referring to flow rate, it refers to a scalar quantity (i.e., a quantity having only magnitude). In other cases, when referring to flow rate, it refers to a vector quantity (i.e., a quantity having both magnitude and direction). Flow rate may be assigned the symbol Q. The term "flow rate" may be abbreviated as "flow" or "airflow" for simplicity.

[0162] Leakage: The term "leakage" is taken as an unintended air flow. In one embodiment, leakage can occur due to an incomplete seal between the mask and the patient's face. In another embodiment, leakage can occur at the swivel elbow with respect to the surroundings.

[0163] Patient: A person with or without a respiratory disease.

[0164] Pressure: Force per unit area. Pressure can be expressed in various units (e.g., cmH2O, g-f / cm 2 , and hectopascal). 1 cmH2O is equal to 1 g-f / cm 2 and is approximately 0.98 hectopascal. In this specification, unless otherwise specified, pressure is given in units of cmH2O.

[0165] Respiratory Pressure Therapy (RPT): The addition of an air supply to the airway inlet at a therapeutic pressure that is typically positive pressure with respect to the atmosphere.

[0166] Seal: When used as a noun ("seal"), it can refer to a structure, and when used as a verb ("seal (off)"), it can refer to its effect. Two elements can be constructed and / or arranged to "seal" or obtain a "sealing" effect between them without the need for a separate "seal" element itself.

[0167] 5.9.2 Patient Interface Pneumatic Chamber: The mask pneumatic chamber is taken to mean a part of the patient interface having a wall that at least partially encloses a volume of space, and the air in the volume is pressurized to exceed atmospheric pressure during use. The shell can form part of the wall of the mask pneumatic chamber.

[0168] Shell: The shell is taken to mean a relatively thin, curved structure having bending, tensile, and compressive rigidity. For example, the curved structure wall of a mask can be a shell. In some forms, the shell can be faceted. In some forms, the shell can be airtight. In some forms, the shell may not be airtight.

[0169] Vent: (noun): A structure that allows air flow to the ambient air inside a mask or conduit, enabling a clinically effective flushing of the exhaled gas. For example, in a clinically effective flushing, a flow rate of about 10 liters per minute to about 100 liters per minute can be used depending on the mask design and the therapeutic pressure.

[0170] 5.10 Other Precautions Part of the disclosure of this patent document contains content that is protected by copyright. The copyright owner has no objection if someone reproduces this patent document or this patent disclosure by fax, as long as it appears in the patent file or record of the Patent Office. However, for other purposes, all copyrights are retained.

[0171] Unless otherwise clearly apparent from the context and unless a range of values is provided, it is understood that each intervening value between one-tenth of the unit of the lower limit, between the upper and lower limits of the range, and any other stated value or intervening value within the stated range is encompassed by the present technology. Even if the upper and lower limits of these intervening ranges independently included within an intervening range particularly exceed the limits in the stated range, they are still encompassed by the present technology. If the stated range includes one or both of these limits, ranges exceeding either or both of these stated limits are also encompassed by the present technology.

[0172] Furthermore, when values (singular or plural) are embodied as part of the present technology in this specification, unless otherwise specified, it is understood that such values can be approximated and used to any appropriate significant digits up to the range permitted or required by practical technical implementation.

[0173] Unless otherwise specified, all technical and scientific terms in this specification have the same meaning as commonly understood by those skilled in the art to which the present technology pertains. Any methods and materials similar to or equivalent to those described in this specification can be used in the practice or testing of the present technology, although a limited number of exemplary methods and materials are described in this specification.

[0174] Although a specific material is described as being preferably used for the construction of a component, obvious alternative materials with similar properties can be used as substitutes. Furthermore, unless stated to the contrary, any and all components described in this specification are understood to be manufacturable and can be manufactured either collectively or individually.

[0175] As used in this specification and the appended claims, it should be noted that the singular forms "a", "an" and "the" include their plural equivalents unless the context clearly indicates otherwise.

[0176] In this specification, the term "about" is used to represent an amount that varies by about 30%, preferably about 20%, more preferably about 10% with respect to a reference amount. Using the word "about" to modify a number merely indicates that the number should not be construed as an exact value.

[0177] All the published documents described in this specification shall, by reference to the disclosure and description of the methods and / or materials that are the subject of these published documents, form part of this specification. The published documents discussed in this specification are provided only for their disclosure prior to the filing date of this application. Nothing in this specification should be construed as an admission that the technology precedes such published documents for the purposes of prior art. Further, the dates of the published documents described may differ from the actual dates of the published documents and may need to be individually verified.

[0178] The terms "comprises" and "comprising" should be construed to refer to elements, components or steps in a non-exclusive sense, indicating that the recited elements, components or steps may be present, utilized or combined with other elements, components or steps not expressly recited. Thus, unless the context otherwise requires, throughout this specification, the word "comprising" is meant to suggest the inclusion of the recited step or element, or group of steps or elements, but not to suggest the exclusion of other steps or elements, or group of steps or elements. The term "including" as used in this specification is also an open term meaning at least including the element / feature following the term without excluding others. Thus, "including" is synonymous and equivalent to "comprising".

[0179] The various methods or processes outlined in this specification may be encoded as software executable by one or more processors using any of a variety of operating systems or platforms. Additionally, such software may be described using any of several suitable programming languages and / or programming tools or scripting tools, and may also be compiled as executable machine code or intermediate code to be executed on a framework or virtual machine.

[0180] In this regard, various inventive concepts may be embodied as a processor-readable medium or computer-readable storage medium (or plural such storage media) (e.g., computer memory, one or more floppy disks, compact disks, optical disks, magnetic tapes, flash memory, circuit configurations within a field programmable gate array or other semiconductor device, or other non-transitory media or tangible computer storage media) encoded with one or more programs or processor control instructions that, when executed by one or more computers or other processors, perform a method of implementing various embodiments of the techniques described above. This computer-readable medium (singular and plural) may be portable, and the program or programs stored thereon may be loaded onto one or more different computers or other processors to implement the various aspects of the present technology described above.

[0181] As used herein, the terms "program" or "software" are used in their ordinary sense and refer to any type of computer code or any set of computer-executable instructions that can be employed for the purpose of programming a computer or other processor to implement the various aspects of the embodiments described above. Additionally, according to one aspect, one or more computer programs that, when executed, implement the methods of the present technology need not reside on a single computer or processor and may be understood to be distributed in a modular fashion across a number of different computers or processors for implementing the various aspects of the present technology. For example, some versions of the present technology may include a server having access to either a computer-readable medium or a processor-readable medium described herein. The server may be configured to receive requests to download processor control instructions or processor-executable instructions of the medium to an electronic device such as a smart phone or a smart speaker over a communication network, the Internet, or a network such as the Internet. Thus, such an electronic device may also include such a medium for executing the instructions of the medium. Similarly, the present technology may be implemented as a method by which a server accesses any of the media described herein. The method(s) may include receiving, at the server, a request to download processor-executable instructions of the medium over a network to an electronic device, and a request to transmit the instructions of the medium to the electronic device in response to the request. Optionally, the server may access the medium for executing the instructions of the medium.

[0182] Computer-executable instructions can be in many forms, such as program modules, executed by one or more computers or other devices. In general, program modules may include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Typically, the functions of program modules can be combined or distributed as needed in various embodiments.

[0183] Also, the data structure can be stored in a computer-readable medium in any suitable format. For the sake of simplicity of illustration, the data structure can be shown as having fields that have relationships through their positions within the data structure. Such relationships can be similarly realized by assigning to the storage devices of each field the positions within the computer-readable medium that convey the relationships between those fields. However, any suitable mechanism can be used, such as using mechanisms like pointers or tags that establish relationships between data elements to establish relationships between the information within the fields of the data structure.

[0184] Regarding the technology in this specification, although specific embodiments have been described with reference to them, it should be understood that these embodiments are merely illustrative of the principles and applications of the technology. For example, in this specification, an acoustic generator and acoustic monitoring techniques are described in specific embodiments regarding the use of RPT device(s) and component(s). However, such acoustic generator and acoustic monitoring techniques can be similarly implemented in component(s) of any respiratory therapy (RT) device, such as a high-flow therapy (HFT) device that provides a controlled air flow at a therapeutic flow rate level through a patient interface. Therefore, the HFT device is similar to a pressure-controlled RPT device but is configured to have a controller for flow control. In such an embodiment, the acoustic generator can be configured to measure gas characteristics associated with the high-flow therapy generated by the HFT device and can be integrated to sample the gas flow in the patient circuit, its conduit coupler, and / or the patient interface of the HFT device. Therefore, the HFT device can optionally also include an acoustic receiver in addition to the processing techniques for acoustic analysis described herein to receive the acoustic / sound signals generated by the HFT device in which the acoustic generator is implemented.

[0185] In some cases in this specification, terms and symbols may indicate specific details that are not necessary for the implementation of this technology. For example, terms such as "first" and "second" (etc.) are used, but unless otherwise specified, these terms are not intended to indicate any order and are used to distinguish separate elements. Further, the description or illustration of process steps in this method may be presented in an ordered manner, but such an order is not necessary. A person skilled in the art will recognize that such an order can be changed and / or the operations can be performed simultaneously or further synchronously.

[0186] Therefore, it should be understood that numerous variations are possible in exemplary embodiments without departing from the spirit and scope of this technology, and other arrangements can be devised. The description of the claims in the original application is as follows. Claim 1: A pressure generator configured to generate pressurized air supplied from an outlet along an air circuit to a patient interface; A sensor configured to generate a sound signal representing the sound of the pressure generator in the air circuit; An attenuation structure configured to reduce reflection of sound from the pressure generator along the air circuit; A controller configured to process the sound signal to identify the patient interface and / or the air circuit A device for producing respiratory therapy, comprising: Claim 2: The device according to claim 1, wherein the attenuation structure is formed by a through-pass attenuation duct configured to vary acoustic impedance between the air circuit and a cavity of the housing of the pressure generator. Claim 3: The device according to claim 2, wherein the attenuation structure defines a cross-section of a passage through the through-pass attenuation duct such that the cross-section expands along the path of the passage according to the shape of the inner surface of the through-pass attenuation duct. Claim 4: The device according to claim 3, wherein the cross-section gradually expands as it moves away from the patient interface end of the air circuit. Claim 5: The device according to any one of claims 1 to 4, comprising at least a waveguide formed by the outlet and the air circuit, wherein the attenuation structure is disposed between the sensor and the outlet along the waveguide, and the sensor is disposed between the attenuation structure and the air circuit along the waveguide. Claim 6: The device according to any one of claims 1 to 5, wherein the attenuation structure is formed by a horn. Claim 7: The device according to claim 6, wherein the horn has a conical shape. Claim 8: A method for identifying components of an air path coupled to a respiratory therapy device in a processor associated with the respiratory therapy device, the method comprising: Processing the sound signal, including flattening the spectrum of the sound signal representing the sound in the air path to obtain a cepstrum; Separating an acoustic signature from the cepstrum; comparing the acoustic signature with a set of predetermined acoustic signatures corresponding to respective components; identifying the component based on a comparison between the acoustic signature and the set; A method comprising the steps of. Claim 9: The method according to claim 8, wherein the flattening includes removing, from the logarithmic spectrum of the sound signal, the logarithmic spectrum of a low-pass filtered version of the sound signal. Claim 10: The method according to claim 9, wherein the removing includes subtracting. Claim 11: repeating the processing and separating at least once to generate a plurality of acoustic signatures; combining the plurality of acoustic signatures into a composite acoustic signature; The method according to any one of claims 8 to 10, further comprising comparing the composite acoustic signature with the set of predetermined acoustic signatures. Claim 12: The method according to claim 11, wherein the combining includes aligning one or more of the plurality of acoustic signatures with the composite acoustic signature. Claim 13: The method according to claim 11 or 12, wherein the combining includes averaging the plurality of acoustic signatures. Claim 14: The method according to any one of claims 11 to 13, wherein the component is a patient interface, and the repeating is synchronized with a respiratory cycle of a patient wearing the patient interface. Claim 15: The method according to any one of claims 11 to 14, wherein the combining is robust to small variations in delay between the plurality of acoustic signatures. Claim 16: The method according to any one of claims 8 to 15, further comprising adjusting control parameters for operating a pressure generator of the respiratory therapy device based on the identifying. Claim 17: a pressure generator configured to generate pressurized air supplied from an outlet along an air circuit to a patient interface; a sensor configured to generate a sound signal representative of the sound of the pressure generator within the air circuit; A process including flattening the spectrum of the sound signal is performed to obtain a cepstrum, an acoustic signature is separated from the cepstrum, the acoustic signature is compared with a set of predetermined acoustic signatures corresponding to respective components, and a controller configured to identify the patient interface and / or the air circuit based on the comparison between the acoustic signature and the set A device for generating a respiratory therapy comprising. Claim 18: The device according to claim 17, further comprising an attenuation structure configured to reduce reflection of sound from the pressure generator along the air circuit. Claim 19: The device according to claim 18, wherein the attenuation structure is formed by a pass-through attenuation duct configured to change acoustic impedance between the air circuit and a cavity of the housing of the pressure generator. Claim 20: The device according to claim 18 or 19, wherein the attenuation structure is formed by a horn. Claim 21: The device according to claim 20, wherein the horn has a conical shape. Claim 22: The device according to any one of claims 17 to 21, wherein the controller is further configured to adjust control parameters for operating the pressure generator based on the identified patient interface and / or air circuit. Claim 23: A method for identifying components of an air path connected to a respiratory therapy device in a processor associated with the respiratory therapy device, comprising: Processing a sound signal representing sound in the air path to obtain a cepstrum; Separating an acoustic signature from the cepstrum; Repeating the processing and separation at least once to generate a plurality of acoustic signatures; Combining the plurality of acoustic signatures into a composite acoustic signature; Comparing the composite acoustic signature with a set of predetermined acoustic signatures corresponding to respective components; and Identifying the components based on the comparison between the acoustic signature and the set. A method including. Claim 24: The method according to claim 23, wherein the combining includes aligning one or more of the plurality of acoustic signatures with the composite acoustic signature. Claim 25: The method according to claim 23 or 24, wherein the combining includes averaging the plurality of acoustic signatures. Claim 26: The method according to any one of claims 23 to 25, wherein the component is a patient interface, and the repeating is synchronized with the breathing cycle of a patient wearing the patient interface. Claim 27: The method according to any one of claims 23 to 26, wherein the combining is robust to variations in the delay between the plurality of acoustic signatures. Claim 28: The method according to any one of claims 23 to 26, wherein the processing includes flattening the spectrum of the audio signal. Claim 29: The method according to claim 28, wherein the flattening includes subtracting a low-pass filtered logarithmic spectrum from the logarithmic spectrum of the audio signal. Claim 30: The method according to any one of claims 23 to 29, further comprising adjusting control parameters for operating a pressure generator of the respiratory therapy device based on the identifying. Claim 31: A computer-readable medium having computer-readable instructions encoded thereon that, when executed by a processor of a controller of a respiratory therapy device, cause the processor to execute the method according to any one of claims 8 to 16 and claims 23 to 30. Claim 32: A pressure generator configured to generate pressurized air that is supplied from an outlet along an air circuit to a patient interface; A sensor configured to generate an audio signal representative of the sound of the pressure generator within the air circuit; A controller configured to process the audio signal to obtain a cepstrum, separate an acoustic signature from the cepstrum, repeat the processing and separating at least once to generate a plurality of acoustic signatures, combine the plurality of acoustic signatures into a composite acoustic signature, compare the composite acoustic signature with a set of predetermined acoustic signatures corresponding to respective components, and identify the patient interface and / or the air circuit based on the comparison of the acoustic signature with the set. A device for generating a respiratory therapy comprising the above. Claim 33: The device according to claim 32, further comprising an attenuation structure configured to reduce reflection of sound from the pressure generator along the air circuit. Claim 34: The device according to claim 33, wherein the damping structure is formed by a through-pass damping duct configured to change the acoustic impedance between the air circuit and the cavity of the housing of the pressure generator. Claim 35: The device according to claim 33 or 34, wherein the damping structure is formed by a horn. Claim 36: The device according to claim 35, wherein the horn has a conical shape. Claim 37: The device according to any one of claims 32 to 36, wherein, in order to combine the plurality of acoustic signatures, the controller is configured to match one or more of the plurality of acoustic signatures with the composite acoustic signature. Claim 38: The device according to claim 36 or 37, wherein, in order to combine the plurality of acoustic signatures, the controller is configured to average the plurality of acoustic signatures. Claim 39: The device according to any one of claims 32 to 38, wherein the controller is further configured to adjust control parameters for operating the pressure generator based on the identified patient interface and / or air circuit.

Explanation of Symbols

[0187]

Table 1A

Table 1B

Table 1C

Table 1D

Table 1E

Claims

1. A pressure generator configured to generate pressurized air supplied along a pneumatic path of a device for creating a respiratory therapy having an outlet, wherein the supply of the pressurized air is generated from the outlet along an air circuit to a patient interface, a sensor configured to generate a sound signal representative of the sound of the pressure generator within the air circuit, an attenuation structure configured to reduce reflection of sound from the pressure generator along the air circuit, wherein the attenuation structure is configured within the pneumatic path of the device and is between the pressure generator and the sensor, and a controller configured to process the sound signal to identify the patient interface and / or the air circuit A device for creating a respiratory therapy, comprising:

2. The device according to claim 1, wherein the attenuation structure is formed by a through-pass attenuation duct configured to vary acoustic impedance between the air circuit and a cavity of a housing of the pressure generator.

3. The device according to claim 2, wherein the attenuation structure defines a cross-section of a passage through the through-pass attenuation duct such that the cross-section expands along a path of the passage according to a shape of an inner surface of the through-pass attenuation duct.

4. The device according to claim 3, wherein the cross-section gradually expands as it moves away from a patient interface end of the air circuit.

5. The device according to any one of claims 1 to 4, wherein the device comprises a waveguide formed at least by the outlet and the air circuit, the attenuation structure is disposed between the sensor and the outlet along the waveguide, and the sensor is disposed between the attenuation structure and the air circuit along the waveguide.

6. The device according to any one of claims 1 to 5, wherein the attenuation structure is formed by a horn.

7. The device according to claim 6, wherein the horn has a conical shape.

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